OF TECHiV 0 OCT 2 1961 LIBRARV ON THE DYNAMICS OF WOOL SPINNING by ALY H.M. EL-SHIEKH B.Sc. "Mechanical" Alexandria University Alexandria, U.A.R. (1956) SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY August 1961 Signature of Author Signature redacted-Depaftment of Mechanical Engineering Textile Division, August 18, 1961 Certified by Signature redacted ThesIs Supervisor Accepted by Signature redacted Chairman, Department Committee on Graduate Students 'The tapestry is woven -- watch the fabric grow As ply the shuttles 'neath the weavers skillful hand; Following the pattern far above, where pulse and glow Rich colors brought together as the master planned. Faint outlined are the figures, for the cloth is turned Face-in before a mirror, where there will be found An image of the whole design. Fires of creation burned When first the master painted sharp against the ground desires, and then hung it there behind the weaver heart's His Where it is not seen directly, but reflected through the mist of thread which forms a gauzy curtain.' Edward R. Schwarz ii ON THE DYNAMICS OF WOOL SPINNING by ALY H.M. EL-SHIEKH Submitted to the Department of Mechanical Engineering, Textile Division, on August 18, 1961 in partial fulfillment of the requirements for the degree of Master of Science. ABSTRACT In this investigation, four differently designed spindles were used to measure the vibration of each on the spinning frame. The tests were carried out to find the most stable of the four spindles. A high sensitivity, high frequency response tensiometer was used to measure the yarn tension with three of the spindles. The average tensions were applied to the balloon theory of De Barr for the purposes of verification of his expressions. Vibration results indicate that there is no significant difference betwen the four spindles. They also indicate that the driving shaft, and the flyer at the top of the bobbin, are the main sources of vibrations. Tension measurements indicate that two of the four spindles are quite stable, and that the balloon theory of De Barr is fairly well substantiated. iii Massachusetts Institute of Technology Department of Mechanical Engineering Textile Division Cambridge 39, Massachusetts August 18, 1961 Professor Philip Franklin Secretary of the Faculty Massachusetts Institute of Technology Cambridge 39, Massachusetts Dear Sir: In accordance with the requirements for the degree of Master of Science in Textile Technology, I hereby submit my thesis entitled "On the Dynamics of Wool Spinning". Respectfully submitted, Signature redacted Aly H. M. El-Shiekh AES :rm iv ACKNOWLEDGEMENTS I express my sincere gratitude to Professor Stanley Backer for his guidance, criticism and encouragement during the course of this investigation. I also extend my thanks to the Davis & Furber Machine Company of North Andover, Massachusetts and particularly to Messrs. J. Kooistra and J. Frye for their cooperation all through the duration of this study. Special thanks are due to my friends J. Krizik, S.K. Batra, and B.J. Park for their help during this work. I wish to express my appreciation to Miss Rose Messoumian for her many typing hours in the preparation and typing of this thesis. I take this opportunity to recognize the patience and sacrifices of my mother and wife for their encouragement and devotion, V CONTENTS Page Chapters I. Introduction............... 1 II. Instrumentation............ 7 III. Balloon theory............. 14 IV. Vibration theory........... 24 V. Experiments and observation 37 55 VI. VII. Calculations and results... 87 VIII. Discussion................. 93 IX. Conclusion. X. Recommendation for spinning frame 103 improvements............... .* . * .. e. APPENDIX 1: * ................... 106 Use of spinning frame for further, 110 2: Plotting of vibration data......... APPENDIX 3: Typical tension signals and balloon configurations REFERENCES . .... .. . .. .. . .. ..... . APPENDIX 112 141 153 .. . . . . . . . .. . . . . . .. vi LIST OF FIGURES _Page Figures 1 Diagramatic representation of ring spinning 3 la Basic action in ring spinning.............. 3 2 Spinning frame............................. 5 3 4 9 Equipment for vibration measurements....... Frequency characteristic of vibration pick-up 10 5 Capacitance of vibration pick-up vs. temperature........................... . . 6 Equipment for measurement of tension....... 7 Forces acting on an element of yarn in the 10 13 . . . . . 18 8 Forces acting ontraveller................. 18 9 18 10 Yarn tension as a function of angle of lead Tension at balloon apex vs. balloon height 11 Tension at balloon apex vs. weight of balloon..... . . . . . . . . . . 21 traveller....... ............. 22 12- Tension at balloon apex vs. weight of yarn 23 13 Fixed 14 Deflection curve of spindle................ Diagramatic sketch of the package on spindle 28 P1 and P 2 vs. a L 35 15 16 17 column............................... 28 28 s Effect of package diameter on spindle . ........ vibration.................. ..... 36 18 Mounting of spindle #1..................... 39 18a Cross-section of spindle #l............... 40 19 20 Mounting of spindle #2..................... 41 42 21 Diagramatic sketch of spindle #3........... Mounting of spindles #3 and #4............. 22 Spindle and pulley drive.................. 46 vii 43 LIST OF FIGURES (Continued) 23 Diagramatic sketch of shaft vibration measurement arrangement................... 46 24 Calibration curve of tensiometer.......... 51 25 Damage and wear of traveller....... 52 26 Rupturing strength vs. twist 27 Amplitude of vibration of shaft vs. r.p.m. e..... 53 of spindle................................ 54 Experimental tension vs. balloon height.... 102 29 Cross-section of sugge sted shaft...... .0.. 108 30 Diagramatic sketch of suggested spindle rai 1 109 31 Plott of test A 1 113 . . 28 Plott of test A 2 Plott of test A 114 . 32 ..... 33 115 . 3 '' ' ' ' ''' ' .. 0 . . . . . . . .. 0 . . . . . * Plott of test A . 34 .. g.................. g..... ' ' ' 116 ..... Plott of test B 1 Plott of test B . . 117 . . 118 . 35 36 . . . 2 Plott of test B 3 Plott of test B ..................... ..... 119 . 37 Plott of test C 1 Plott of test C 121 ..... ..... . 39 120 . 38 2 ..... Plott of test C 3 Plott of test C ..................... 123 . 41 122 0 .e... . 40 42 ,.. 124 . 4 ... Plott of test D 1 Plott of test D . 43 44 ..... 125 ..... ..... 0 126 . 2 ..... Plott of test E 1 Plott of test E ..... . 47 48 128 . 46 127 Plott of test D 3 Plott of test D . 45 129 130 . 2 131 Plott of test E 3 Plott of test E4 . 49 132 . 50 viii LIST OF FIGURES (Continued) 133 51 Plott of test 52 Plott of test F 2 53 Plott of test F3 . .... 54 Plott of test F4 . .... 55 Plott of test 56 57 Plott of test G 2 . Plott of test 58 Plott of test 59 Test I H 60 Test I H 61 Test I H 62 Test J H 63 Test J H 64 Test J H 65 Test K H 66 Test K H 67 Test K H 68 Test L H 69 Test L H 70 Test L H 71 72 Balloon shape for Test Balloon shape for Test 73 F1 . .... 000 0 135 00.0 0 136 137 138 .... 139 140 G1 31...... - 0 0000 143 - 143 10.5".. 14. 0".. . 000 143 - 14. 0" - 13 *0". - 144 10.5". is.o''... 145 - - 144 16.5".. 145 0 0000 144 . .. 145 146 - - 000 - 0 146 16.5"... 146 311* 147 148 Balloon shape for Test 10.5" 14.0" 74 Balloon shape for Test 13.0" 150 75 Balloon shape for Test 15.o0" 151 76 Balloon shape for Test 16o5" 152 ix L 134 0 000 *** 149 9 19 09 o o0 00 0 00 6L 00 9 o0*0o*0o0o000o* 0 0..0. 00 00 0 0 0 00 0 0 0 0 00 0 0 0 0 * 0 0 0 0 0 0 0 00 0 0 0000 0 0 * 0 0 0 *0 o 0 o 0 a0 0 0 0 0 0 0 0 0 0 0 0 0 0a 00 0*0 * 0o 0 00 x ooo o 0 0 0*000 0 0 000 o 0 0 0 ooo#oo 0 0 000 0* 0 00 0 0 0 0 0 0 0 0 a 0 (47D) EDt) (1j) (1751) C5 0 0 0 (1 0 0 0 0 o *o so9o ooo I s 61 l9 :iS 1 , :a S lE :1 So T) :3 (D*0 :1 Q ( Tg) 0 *0 0 0 olO ol6 a Sl 1L :12 s :1Sl lc :4s J :199, Soj 91 O 91 -I Sl ) 71 :iSol (47,) 9o o * o 1 ) (CT 0 0 0 0 E~D) 0 0 0 0 0 0 0 0 0 0 0 0 00 000 0 00 1 9o I 91So 63 (4 y 00 0 * 0 0 0 0 & 0**0 0 (sa) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 * 0 (470 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 *0 0 0 0 0 0 :4~ 3) (TZ) aT a 000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 90 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 *0 0 00 0 0 0 0 0 *0 0 0 0* 0 * 0* 0 0 0 0 0 0 0 0 00 o ooooo 00 00 00 0 0 0 0 0 0 0 0 0 0 *0 00 0 0 19 09 0 0 * 0 00 * 0 0 0 0 qZ~ L (~ 0 0 0 & 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 ID~) (VAd) 0 00 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0. 0 0 0 *o o 0 0 0 0 0 0 00 oo 0 0 0 a 0 0 0 0 0 0 0 0 0 0 000000 ) 0 00 0 00 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 o 0 0 0 0 0 0 0 oo o 0 0 0 0 0 0 0 0 0 0 0 0 0 0* 0 0 0 0 0 0 0 o 0 0 0 0 0 0 0 0 0 00 00 0 0 0 0 0 00 000 0 0 0 0 0 9 97L CL0 170o CL 69 99 9 99 0 0 0 0 0 99 479 0 0* 69 * 0 1 so, L000 09 9* oo*9*9**o****(7) : g o0 0 0 0 0 O O O O O O 1l3 3 4 O o o o(y Z 3~ T a~flpaqos Ia uo-jIaqJA IO -oqaaiso 047 o1qul I3a STI9V1 AO LsilI LIST OF TABLES (Continued) vibration of main shaft... 000 ... 84 31 Test (H) 32 Test (I) experimental results at 5, 000 r.p.m. 85 33 Test (J) experimental results at 6, 000 r.p.m. 85 34 Test (K) experimental results at 5,000 r.p.m. 86 35 Test (L) experimental results at 6,000 r. p.m. 86 36 Results for spindle #1............. 92 37 Results for spindle #3 92 38 Results for spindle #4 92 xi 1 I. INTRODUCTION 2 Spinning has been defined as the art of twisting fibrous materials to form a continuous yarn suitable for weaving. The process of spinning is composed of several continuous sub-processes (Fig. 1). To produce a yarn suitable for weaving, one which has coherence strength and extensibility, the spinning process should permit uniform quantities of fibers to be drawn out in a continuous manner and uniform twist to be inserted at a specified level. Thousands of years ago, spinning was carried out in India and such yarns were woven into fine fabrics. It would appear that the Indian spinning had gone on through the ages with the same degree of perfection as was observed at the time when the spinning mule was developed. Ring spinning was brought to the United States in 1828 and applied to the cotton industry. However, its introduction to the Bradford system in the U.S.A. did not come until 1930, a century after its invention, even though it had been universally used by the cotton spinners for a number of years. Ring spinning is most suitable for the production of worsted yarns varying from 1 to 70s qualities. After replacement of the mule frame by the ring spinning system, improvements in ring spinning have been 3 Front roller Flyer Balloon Bobbin N Spindle Guiding ring "N r Traveller Ring Ring r:il Figure 1 Diagramatic Representation of Ring Spinning I -I-- 0- V 10 Ua (Or Figure la Basic Action in Ring Spinning (After Schwarz 10) 4 concentrated previously ip the area of spinning larger packages at higher rates of speed. The fact that large packages can be used here enables a spinner to produce long lengths of continuous yarns for Practical experience and weaving and knitting purposes. scientific tests have definitply established the fact that quality of the yarn does not suffer in any way from the use of large yarn packages. They are preferred in many cases because they contain only about 25% of the knots found in cap-spun yarn which is limited in package size. With the increase of spinning speeds numerous troubles were encountered, troubles primarily in the form of mechanical vibrations, yarn breakage and traveller wear. We are concerned here primarily with the vibration problem. These vibrations restricted the manufactures to a certain range of speeds, not to be exceeded, without breaking the yarn or damaging the machine. This thesis is a study of certain vibration problems encountered in woolen spinning. The spinning frame which we have used in this study was manufactured by the Davis and Furber Machine Company of North Andover, Massachusetts. The frame (Model F ) shown in (Fig. 2) consists mainly of a head stock containing the driving motor and 5 Figure 2 Spinning Frame 6 all gears which transmit power to the different parts of the machine. This power is transmitted to a main shaft carrying a series of pulleys from which the spindle (in groups of four) are belt driven. To permit continuous winding of the package, a spindle rail is provided with vertical reciprocating motion. To prevent large balloon heights and accompany high balloon tension the manufacturer of this frame has introduced a flyer fixed on the top of the bobbin. The use of this flyer as the apex point of the balloon instead of the usual pig tail shortens the balloon considerably and by reducing spinning tension permits higher spinning speeds. On the other hand the use of the flyer increases the forces on the spindles, which causing it to deflect and vibrate excessively at higher speeds. Thus the limitation on speed is no longer the yarn property, but is the machine construction. 7 II. INSTRUMENTATION 8 In our investigation of the vibration of this spinning frame different pieces of equipment were used to measure the following quantities. a. The vibration amplitude of different parts of the machine. b. The yarn tension during spinning. In measuring the amplitude of vibration a vibration meter manufactured by General Radio Company 2 while a tensiometer 2 was used, was used in measuring the yarn tension during spinning. Description of the vibration meter The type 761-A vibration meter (No. 2, Fig. 3) can be used for measurements of low frequency vibration. It is mounted in a carried case and operates from an internal battery. The vibration meter is supplied with a vibration pick up (No. 1, Fig. 3) of the piezo-electric type. The electrical circuit of the vibration meter consists mainly of two electrical integrators built in as a part of the amplifier because the pick-up is of the inertia type, i.e. an accelerometer. In the pick-up used, the crystal is deflected by its own inertia when it is subjected to vibration. The voltage 9 Figure 3. Equipment for Vibration Measurements 1. Vibration Pick-up 2. Vibration Meter 10 .0 5 - - -- r4 0 ___ ___4- 0-00~- __ , _ __- - Tw 50 /00 ;O 5 10 20 Frequency Cycles/sec. 1000 2-0 Figure 4 Frequency characteristic of vibration pick up (after E. Gross (1) L /0000 -- 0r U PI aI -<I I~L~ I C.) C-, 000 N~K~ I ilititiI I I-I 0 q0 60 80 100 I bo Temperature of pick up *F Figure 5 Capacitance of vibration pick up versus temperature (after E. Gross (1) I 11 generated by the crystal is proportional to the inertial force exerted on the crystal, which is proportional to the acceleration. The vibration meter reads and measures directly the r.m.s. (root mean square) of displacement, velocity, and acceleration. It measures as low as 16 micro-inches displacement, 160 micro-inches/ sec. velocities or as low as 0.16 inches/sec acceleration. Characteristics of the pick-up were as follows. An inertia operated Rochelle salt crystal performing as an accelerometer. Fig. 4. Its frequency characteristic is shown in As with all Rochelle salt devices, its maximum safe operating temperature is 115*F. Its temperature characteristics is shown in Fig. 5. Tension Measuring Instruments Fig. 6 shows the arrangement of the equipment used in measuring the yarn tension. The tensiometer Fig. 6-1 consists of an aluminum cantilever beam with a system of pulleys together with a linear variable differential transformer. The core of the transformer is attached to the end of the beam, so that it can change position according to the deflection of the beam. The linear differential transformer is an electro- 12 mechanical transducer producing an electrical output which is linearly proportional to the displacement of its movable core. The electrical output appears as two voltages in opposite direction and the net output of the gage in the difference between them. As the position of the core where the two voltages are of the same magnitude the net output of the gage is zero, and is referred to as the minimum balance point or mechanical null point. However in practice the output voltage at the null point does not quite reach zero because of small residual voltage components which do not cancel. Together with the tensiometer, some other standard measuring instrumentation is used (Fig.62,3,4,5 ,6 inclusive). A Tektronix oscilloscope (Fig. 65) employed to measure the voltage, a Polaroid camera (Fig. 66) to record the scope measurement, a Hewlett Packard audio-oscillater (Fig. 62 to provide the excitation for the gage, an R.C.A. Voltohmyst (Fig. 63) to monitor the excitation voltage at all times and a phase correcting network (Fig. 64) to attain maximum sensitivity. 13 Figure 6 Equipments for Measuring Tension 1. 2. 5. Tensiometer Voltohmyst Oscilloscope 2. Audio-Osillater 4. Phase Correccing Network Polaroid Camera 6. mmm-M 14 III. BALLOON THEORY mi 15 NOMENCLATURE The following terms, used in the chapter on Balloon 'theory are defined in the order in which they appear: Tw - Winding tension in the absence of air drag. - Coefficient of friction between traveller and ring. c - Centrifugal force on traveller M - Mass of traveller. R- -M R W2 Radius of rotation of the center of gravity of the traveller. - o are as defined in Figure 8. &'< TT - Yarn tension just before traveller. - Coefficient of friction between yarn and traveller. - Angle of wrap of yarn on traveller. m R Angular velocity of traveller Mass/unit length of yarn. - Radius of rotation of point of contact between yarn and traveller. TwA - Increase in yarn tension due to air drag. C1 - Coefficient of air drag. - Air density d - Yarn diameter A - Maximum radius of balloon H - Balloon height TW - Winding tension including the effect of air drag. 16 Many balloon theories of ring spinning have been proposed over the last 75 years. Some of these theories 3 ,4'5 are in readily usable form while others involve elliptic integrals, or necessitate the use of electronic computers to solve their resulting complicated expressions. Grishin3 in his treatment of the balloon theory neglected the secondary radicals leading to elliptic functions. In his analysis, Grishin assumed that the yarn lies in a vertical plane at maximum and minimum balloon diameters. The work of Cappello practical value. is also considered of great He developed experimental solution for the balloon problem by taking a series of two pictures with synchronized cameras whose axis were perpendicular to each other, thus providing the projection of the balloon shape in two perpendicular planes. One of these two projections can be assumed to be a straight line whose equation can easily be determined, and by the use of simple geometry one can obtain the equation of the entire balloon. De Barr5 in 1958 came up with some expressions which we consider of great practical value. His expressions are employed here as a comparison with our experimental data, obtained by the use of the tensiometer described above. "9. 17 The forces considered by De Barr which act on both an element of the yarn and on the traveller are shown on Figures 7 and 8 respectively. It should be noticed that in his analysis De Barr assumed that the yarn lies in a vertical plane at the point where it passes through the On the other hand his analysis included the traveller. influence of air drag which will deviate the yarn from a vertical plane to a three dimensional shape. Thus it is seen that approximate equations have been established and solved exactly resulting in valid formulae for practical use. Neglecting air drag De Barr showed that the winding tension after tI! traveller and before the bobbin is given by: ___ __ Tr =- e a (1)U __ = = 7(,r. a (2) (3) = (4) Substituting (1) into (2) we get Tr = --d4:% C< cmo 9 +./.4 C'ev C (5) 18 -rS 7; C Fr Figure 8 Forces acting on traveller Figure 7 Forces acting on an element of yarn in the balloon i i 1.0 L- i I I I I I ~1 - 0.6 .1-I 0 4.3 q,4 0. nj- 0.2 0 - Figure 9. 40* A0g 80* 60* Angle of lead Yarn tension as a function of angle of lead (after De Barr (5) 19 Also it can be easily seen that the yarn tension at the apex of the balloon is given by -- Tr r= (6) using the expression for TT we get MU 2 Fig. 9 represents a plot of 0< ( vs / Z (7) ) reported by De Barr for equation (7) neglecting the last term (since in practice T0 and TT do not differ by more than a few percent). In the actual case where the effect of air drag is considered, De Barr found that the increase in winding tension (due to air drag) is given by c, P*a.dA' 3 A 7,- k- 12 4 RAv0 H (8) combining 1 and 8 The total winding tension can be given by AC 7Trr .c I2 ' C -U" c 1*A 33A ra Fig. 10 shows the yarn tension T (9) +C,r 1 d A e3 49J-, ] (10) . To "'eCG~~tA~E as calculated from equation (10) with the rotational angular velocity 20 varied, while Fig. 11 shows it as a function of the traveller size. Also T is plotted in Fig. 12 as a function of the yarn weight/unit length. F000006,- 21 500 400 3 I 1 H- w 0 0 0 300 - r-4 r-4 0 E1 0 y( With flyer at 500C r.p.m. A No flyer at 5000 r.p.m. o With flyer at 6000 r.p.m. a No flyer at 6000 r.p.m. I 10 Balloon height I I 20 30 fo H cm. Figure 10 Tension at the balloon apex vs. balloon height 50 22 3tO 0 I A AA- 0.2 0.3 AA ---- a 0.4 0.5 8 1.0 o0 - p / 0 i / / 20001- 0 r-4 1110 C) 1oool- / I-0 0I *H 0 0 .25 - V 0.5 0.75 Weight of traveller gms. Figure 11 Tension at the balloon apex vs. weight of traveller 23 Ant) I I I I- 350 ,,A , 0 *0 r-I 300, r4 4J 0 e 250 k AD.J I I 3 I 4 Weight of yarn/cm gm/cm 6 Figure 12 Teaision at the balloon apex vs. wcin;ht of yarn/cm length 24 IV. VIBRATION THEORY 4 25 NOMENCLATURE The terms used in the following chapter are defined in the order of their appearance in the text. P.E. = Potential Energy E = Young's modulus of the shaft I - Shaft cross sectional moment of inertia K.E. - Kinetic Energy $s - Mass density of shaft a - Natural frequency of shaft or spindle - Static deflection of a shaft under a static force A - Cross sectional area of shaft - Period of vibration of spindle without package - Period of vibration of spindle with a package on it - L Length of bobbin Spindle diameter D Db = Outside diameter of bobbin D - Max.diameter of package a - Distance between the base of the bobbin and the point where the winding starts. - Spindle mass density Bobbin mass density y - Package (yarn) mass density 26 Vibration in th-Textile Industry Vibration is of great importance in the textile industry because of the delicacy of its product, the speed of its In spinning, machinery and the effect on its mill structures. two types of vibrations can affect the quality of the yarn: 1. Whirling of spindle 2. Torsional vibration of the front roller Both of these two kinds of vibrations affect significantly the quality of the yarn spun. We concentrate here on the first type of spinning frame vibration. In investigating spindle vibration, it is of great importance to examine their flexural vibration, together with the whirling speeds of the spindle blades. This is done for a typical spinning frame manufactured and distributed commercially. Theoretical Background Very little attention had been paid to the problem of spindle vibration in the past. Nissan in an excellent report6 treated the effect of the package on the whirling speeds of spindles. In his analysis he assumed a parabolic shape for the package and applied Dunkerly's principles8 in solving the problem of its vibration. 27 In dealing with the frequencies of flexural vibration we will treat a simple example to show the application of Rayleigh's method. The method equates the maximum potential and kinetic energies of the system. Case 1: By considering the spindle as a column (Fig. 13) fixed at one end and free at the other end, and by assuming a known shape of deflection for the spindle we can now determine its frequencies. Let us assume now that the spindle will follow the shape shown in (Fig. 14) and is given by: 2 LS (11) where The deflection at any point y x - Is measured on the spindle axis Y - Maximum deflection at the free end L - Spindle length The maximum energy in the spindle is given by: P.E El f (12) Substituting for y from (11) we get: which can be integrated to give P.. I S (13) 28 If 7 Ix X Y Y Figure 13. Figure 14. Deflection Curve of Spindle Fixed Column X ===Mo -L 00 71 /i//I/,,, Y Figure 15 Diagramatic sketch of the package on spindle 29 On the other hand the kinetic energy is given by: jiLO~ 0 f6 %a~j ~(14) which, on substituting for y and integrating, gives: k- E = 0.// (s codf !1 aLS (15) Equating the expressions for the K.E. and P.E. we get an expression for the natural frequency of the vibration which is given by: = (16) 6 S .7 The exact solution 5 for the case discussed has the factor 3.52 in it with 0.4% less than the solution discussed here. Case 2: Static Case of a Vertical Light Shaft With a Force Applied at the Free End In the following section we discuss the case of a light shaft having a static force F acting on its free end while the other end is fixed. First we have to determine the static deflection at the tip of the shaft. From strength of materials we know that the deflection under a static force on a cantilever beam is given by: 3(17) 13E I l III 30 From (17) one can obtain a general expression for the force / unit deflection (K): K E. - (18) L3 It is also known that the frequency of vibration W, of a mass m on a massless rod is given by W=J ((19) Then z = (20) Wn Applying these principles to our case we get zir Tx A .. 3 (21) A dx = The period at, a length x of the shaft = Mass density of shaft = Cross sectional area Element of length dx X - Force / unit deflection for a length x Substituting for kX in (21) we get sX A ( i 1 L)2 (22) ,3 E from which (r)a (a2 r) L z r f Ax 31 which after integrating and substituting for the limits gives: O Is the period of the free vibration of the - spindle which can be written as 7n 217'2 (24) where m Mass / unit length of shaft - Effect of the Mass of the Package on the Whirling Speed of the Spindle In discussing the effect of the package of yarn on the spindle vibration we have to assume that the package has a The shape in which the yarn is wound on the known shape. bobbin can take different forms, however we shall assume that the package takes the shape of an ellipsoid. Fig 15 shows a diagramatic sketch of the package. Assuming that the equation of the package is of the form: "W.N A . a. 8 (25) 32 where A and B are constants. Using the boundary conditions we get: A (26) 4 4 LC B Now consi derin- (27) an element of length the weight of the element of the spindle +~ fi from 0 64J ;C - we obtain package combination D 0/j < L-L equals I- s from L- - (* (02 --D|) s (4 4 L and equals from L -a K L The period of vibration of this weight, on a weightless shaft mass is given by 3 where m is the mass of the weight calculated before at point x. We assume that the modulus of the spindle (E) is not 33 affected by the addition of the package and that the moment of inertia I is constant all through the spindle corresponding to its crcss sectional area. We also notice that the spindle blade is the only component (considered here) firmly anchored at one end. Thus to calculate the period of vibration, 'te we can use Dunkerly's principle8 as follows: L 2 - 0 or I.LL 2, {( fJL Xq3 (0- ,)÷ e-I(4 3 '-D-0 XI{f,( D > Z2(o z-4 ')lc dx ~ (28) 2 -O which after integrating between the limits indicated and dividing by t 2 yields T' D, (-p 8 D P where P, P 2 are functions of depending on the ratio L Ls Lc bF , C (29) k c is a constant c and they are given by: ~9~~5 (30) 34 L )4 L)3 ,5 '' 4-( L L s + L)2( -C3 )-3 + 2( ct )4 15 ) 3 (-aL3- ) -1- 6 L z LS Ls Is Fig. 16 shows a plot for the functions P D; 8 - L L while L$ 20 , taking (paper (wool 13 s Db = s 1.144 steel) steel) (31) .4 4 LIS and P 2 Fig. 17 shows a plot for - versus - + versu s )3 4 ( L LS L,5 (32) 35 & P2 1.0 equtios 3-an 1 2 a- 32 6 - 36 O 5 4 0) 0 J-j r-r r13 'V 4-4 0 *4 'r4 O4 'V 0 "-4 . L x 0 1.05 /.5 as rs a r = 0.1 = 0.15 = 0.20 a25 Max. diam. of package/ spindle diameter Figure 17 Effect of package diameter on spindle vibration 37 V. EXPERIMENTS AND OBSERVATIONS 38 In our investigation, four different spindles were chosen on which to run the tests. These spindles have the following constructions: 1. Spindle #1: This spindle shown in Fig. 18 is the original spindle with which the spinning frame is now working. 2. Spindle #2: Is exactly the same as spindle #1 except it has a ball bearing instead of the sleeve in #1 Fig. 19. 3. Spindle #3: in construction. This spindle differs from #1 and #2 It is longer and bigger in diameter, and has a step (point) bearing on which it rests Figs. 20 and 21. 4. Spindle #4: In construction, it looks like spindle #1, but it has a step (point) bearing as #3 on which it rests Fig. 21. These four spindles were chosen so as to permit study of the effect of the different mounts and the different constructions. Tests were carried on to measure the amplitude of vibration at the spindles by means of the vibration meter through the vibration pick-up which was placed on the spindle socket Fig. 3. Tests were conducted on the spindles while they were running free less bobbin, while spinning with the experimental flyer and while spinning without the flyer. *I9( Ball bearing Spindle HousIng Floatg st p bearingg ze Fgure 13 Mouncing oE Spindle #1 J,1_0 it 40 Partially slotted aluminum sleeve I KI *Sd Figure 18a Cross-section of spindle #1 L 41 gall Bearing' Spindl \ouiI Ball //cal Moutin ofSpidle#2 earin houisng 42 Alum inum block to hold the bobbin A Roller bearing Scal e 1 2 Figure 20 Diagramatic sketch of spindle #3 43 /r Spindle i . S1 St.-p Bearir Scale full size ~~rurr~ 21 Mcun: of Spind~es #3 and 4 44 In running the tests while spinning with and without the flyer, three positions for the bobbin were chosen. a. Winding at the bottom of the bobbin. b. Winding at its middle point. c. Winding at its top portion. In all tests readings were taken at intervals of 500 r.p.m. starting at a spindle speed of 1000 r.p.m. The tests data were obtained both on the increasing and decreasing speeds sections of the vibration-speed test cycle. After running the first few tests it was noticed that the two guiding pulleys Fig. 22 which guide the belt driving the spindles from the main shaft, were vibrating excessively. The behavior of these pulleys suggested that additional tests be run with different pulleys conditions: 1. With top and bottom pulleys vibrating. 2. With top pulley fixed while bottom one vibrates. 3. With top and bottom pulleys fixed. 4. With pulley vibrating while bottom is fixed. Tests were also carried on to determine the critical speeds of the driving shaft, for it was noticed to be whirling with a very large amplitude. The tests were carried on by hanging the vibration pick-up by means of a small, well lubricated,smooth steel wire on the shaft 45 31 and plotted in Fig. 23. Data are tabulated in Table Fig. 27, In this latter case the tests were carried on as before, by increasing and decreasing the speeds at intervals of 500 r.p.m. spindle speed. However the special shaft experiments were carried on with no spindles being driven. Test schedules are shown on Table 1. An attempt was made to provide a 3rd bearing support the top of the bobbin while spinning, but practical difficulties prevented the success of this experiment. The fact that the bobbins were not regular in shape and not firmly fixed to the spindles caused the journal of the test spindle to run extremely hot. This objectionable increase in temperature of the spindle was due to its excessive bending strain energy caused by its deflection resulting from the poor allignment of the 3rd bearing. The data for vibration measurements are tabulated in Tables 3 to 31, and plotted in appendix 2 (Figs. 31 to 56). Yarn Tension Measurements: (Table 2) In measuring the yarn tension, the tensiometer was mounted on an external support instead of being mounted on the frame so as to avoid the effect of the latter's vibration. This external support was clamped on a pad mounted table to damp out the frame vibrations. The 46 ,- Top roly G _ Ut main Shaft I7nt _ TensiOP7 Spr.n ! -i Sp indle Spindle orsk, Spri!? Lower Gudin' Pulley 1' Figure 22. Spindle and pulley drive 56" H- 4~77 U-L L Vibration pick up Figure 23. Diagramatic sketch of shaft vibrations measurement arrangement. 47 TABLE 1 Test Schedule for Spindle Vibration Measurement a A1 A2 A3 A4 Pulley Conditions Bottom Pulley v inixCnios mBotmP 1V Tnn Puill t Spinning Conditions Vibrating Fixed fixed Vibrating Vibrating Vibrating Fixed Fixed No Spinning Spinning with Flyer B1 B2 B3 B4 3 3 3 3 Vibrating Fixed Fixed Vibrating Vibrating Vibrating Fixed Fixed C C2 C3 C4 15 15 15 15 Vibrating Fixed Fixed Vibrating D 1 D2 D2 D4 10 10 10 10 E1 E2 E3 E4 it ", it If " Test To Hr it i if ItI ItI it it Vibrating Vibrating Fixed Fixed II it it "I I "I I Vibrating Fixed Fixed Vibrating Vibrating Vibrating Fixed Fixed if to it it it it "1 it 14 14 14 14 Vibrating Fixed Fixed Vibrating Vibrating Vibrating Fixed, Fixed FI F2 F3 F4 17 17 17 17 Vibrating Fixed Fixed Vibrating Vibrating Vibrating Fixed Fixed G G2 G23 G4 15 15 15 15 Vibrating Fixed Fixed Vibrating Vibrating Vibrating Fixed Fixed ____I ___________ Spinning without Flyer "t it -___ I to I " it "t t 48 TABLE 2 K L Spinning Conditions 3.0 5000 With flyer 10.5 5000 " " J R.P.. 14.0 5000 " " I H 3.0 6000 With flyer 10.5 6000 14.0 6000 " 13.0 5000 15.0 5000 16.5 5000 13.0 6030 15.0 6000 16.5 6000 f No flyer No flyer " " Test " Tension Tests Schedule R4 49 changing positions of the yarn resulting from the traversing of the yarn guide caused excessive end breakages when the yarn was unduly strained on the stationary pulley system of the tensiometer. To avoid this, the traversing thread board was secured at its mid position. Another time consuming difficulty was the threading of the end under the central pulley of the tensiometer. Kyros 2 found that satisfactory sensitivity could be achieved by passing the yarn over the three pulley system, rather than having an over-under-over geometry. In the trial tests, observations of the tensions in the scope revealed what appeared to be a significant change in tension with each sweep of the signal. Typical tension signals are shown in appendix 3 flgs.to 69). Also it was noticed that the balloon diameters pulsated to a great degree. From these observations it was clear that any attempt to relate a single sweep photograph of the tension signal to one for the balloon would have little validity without synchronized pictures of the tension signals and the balloon. For this study, visual observations were adapted as less expensive and less time consuming. A series of tests were carried on three different spindles namely (#1, #3 and #4) at three different positions 50 of the ring rail. These tests were carried on at two different spindle speeds with the flyer at the top of bobbin and without the flyer. Table 2 shows the schedule for the tension measurements. Photographs recorded typical tension signals for all the tests at all the conditions previously mentioned. The balloon envelopes were photographed to illustrate the differences that existed as a result of the various changes in test conditions. (Photographs are illustrated in appendix 3.) The tensiometer was calibrated before each test by means of hanging different weights by a thread passing on its poly-system. (A calibration curve is shown in Fig. 24). An external triggering source was used in recording the tension signals to allow only one sweep of the signal to be photographed. The experimental results of average yarn tension are shown in Tables 32 to 35. In all the tests conducted while spinning at high speeds excessive yarn breakages occurred. In all such high speed tests excessive damage and wear of the traveller was common. Typical damaged travellers are shown in Fig. 25. To overcome these troubles a heavy traveller (weight = 0.5 gm) was used together with a heavy two pl-y yarn (total woolen run - 0.53) to withstand the higher tension due to higher 51 speed. To allow the twist to flow over the tensiometer pulley system without breakage. The 0.53 woolen run yarn was twisted to 8.3 turns/inch which is higher than normal for this yarn number (normal is 4 turns/inch). To study the effect of ply twist/inch on yarn breaking load, different twist levels were inserted in different samples both on the spinning frame and on a hand twister. Draft in the frame was 1.069. The twisted yarns were then tested on an Instron Tensile Testing Machine to determine this breaking strength. The gauge length tested was fairly long (12") to allow for fiber slippage. The results obtained from these tests are plotted in Fig. 26. I I I cm. *1~ 4) 0 4 .t- v-I I cii I Oov - 1 00 200 300 Load Figure 24 Calibration curve of tensiometer - - I Saa 60 52 Figure 25 Damage and Wear of Traveller 53 4000 J-j CU CO 0 'r4 4) 05 /0 Twist turns/inch Figure 26 Rupturing strength vs. twist (turns/inch) X Yarn twisted on hand twister 0 Yarn twisted on spinning frame /5 54 350 30Q ~0 OrO P - co H 50-'0 r4 Figure 27. Spindle speed 1000 r.p.m. Amplitude of Vibration of Shaft vs. r.p.m. of spindle 55 VI. DATA 56 TABLE 3 Test A 1 Conditions: No Spinning Top Pulley: Vibrating; Bottom Pulley: Vibrating Vibration Amplitude* 100kA inch Spindle Speed Spindle #1 #2 #3 #4 1.0 1.0 1.5 1.2 2.1 1.5 2.0 2.5 2.4 2.5 2.0 2.5 2.6 3.0 3.0 2.5 7.0 8.0 10.0 8.0 3.0 5.5 4.5 5.2 4.0 3.5 4.5 3.5 3.5 4.5 4.0 4.7 4.0 3.5 5.0 4.5 5.5 4.0 5.7 5.0 5.0 6.0 5.5 6.2 6.0 5.5 7.0 8.5 18.0 20.0 6.0 10.0 15.0 20.0 15.0 6.5 10.0 16.0 8.0 10.0 7.0 7.0 10.0 6.0 20.0 7.5 9.0 18.0 7.5 26.0 8.0 21.0 22.0 30.0 28.0 8.5 25.0 18.0 28.0 22.0 9.0 26.0 15.0 28.0 22.0 9.5 26.0 15.0 26.0 21.0 1000 R.P.M. *Values used here and in the following tables are the average of 6 readings. 57 TABLE 4 Test A 2 Conditions: No Spinning Top Pulley: Fixed; Spindle Speed 1000 R.P.M. Bottom Pulley: Vibrating Vibration Amplitude 100 * inch Spindle #1 #2 #3 #4 1.0 1.0 2.2 2.0 1.5 1.5 2.0 2.4 2.2 2.4 2.0 2.5 2.8 4.5 2.5 2.5 5.0 5.5 6.0 5.5 3.0 6.0 3.5 4.0 5.0 3.5 5.0 4.5 4.0 5.0 4.0 5.5 5.0 4.5 5.0 4.5 6.5 4.5 4.5 6.0 5.0 7.5 8.0 10.0 7.0 5.5 16.0 10.0 15.0 12.0 6.0 20.0 22.0 20.0 22.0 6.5 7.0 15.0 18.0 12.0 7.0 7.5 8.0 10.0 20.0 7.5 9.0 15.0 12.0 25.0 8.0 24.0 26.0 26.0 26.0 8.5 28.0 18.0 30.0 23.0 9.0 28.0 20.0 32.0 22.0 9.5 24.0 21.0 28.0 22.0 58 TABLE 5 Test A 3 Conditions: No Spinning Top Pulley: Fixed; 1000 R.P.M. _ _ Fixed Vibration Amplitude' 100 Spindle Speed L Bottom Pulley: Spindle #1 4A inch #2 #3 #4 1.0 1.0 2.2 1.8 1.5 1.5 1.8 2.4 2.3 2.0 2.0 2.5 3.0 3.0 4.5 2.5 5.0 7.0 6.0 5.0 3.0 5.0 4.0 5.0 4.3 3.5 4.5 3.5 4.0 4.0 4.0 5.0 4.0 4.0 4.0 4.5 5.5 7.0 4.5 6.5 5.0 7.0 9.0 7.0 7.0 5.5 12.0 15.0 15.0 20.0 6.0 15.0 26.0 20.0 24.0 6.5 9.0 20.0 20.0 15.0 7.0 8.0 15.0 7.0 12.0 7.5 20.0 21.0 21.0 24.0 8.0 28.0 24.0 22.0 25.0 8.5 30.0 26.0 28.0 22.0 9.0 28.0 21.0 30.0 22.0 9.5 24.0 21.0 28.0 21.0 _ _ _ I 59 TABLE 6 Test A 4 Conditions: No Spinning Top Pulley: Vibrating; Spindle Speed 1000 R.P.M. Bottom Pulley: Vibration Amplitude Spindle #1 Fixed 100,a inch #2 #3 #4 1.0 1.5 2.0 2.2 2.1 1.5 2.1 2.3 2.5 2.5 2.0 3.0 3.0 3.0 4.5 2.5 5.5 5.5 6.0 8.0 3.0 7.0 4.0 5.5 4.0 3.5 4.0 4.5 4.0 5.0 4.0 4.5 3.5 4.0 4.5 4.5 5.5 5.0 5.5 6.0 5.0 5.5 6.0 5.5 7.0 5.5 9.0 10.0 8.0 18.0 6.0 9.0 22.0 10.0 20.0 6.5 7 0 12.0 6.0 12.0 7.0 8.0 7.0 5.5 15.0 7.5 15.0 18.0 15.0 30.0 8.0 26.0 25.0 20.0 25.0 8.5 27.0 22.0 26.0 22.0 9.0 28.0 20.0 28.0 22.0 10.0 26.0 20.0 27.0 22.0 60 TABLE 7 Test B Conditions: H - Spinning with Flyer 3 inches Top Pulley: Spindle Speed Vibrating; Bottom Pulley: Vibrating Amplitude of Vibration 100," inch Spindle #1 #2 #3 #4 3.0 18.0 18.0 20.0 22.0 3.5 9.0 24.0 7.0 12.0 4.0 10.0 18.0 15.0 12.0 4.5 18.0 21.0 18.0 21.0 5.0 20.0 24.0 10.0 15.0 5.5 21.0 26.0 21.0 22.0 6.0 22.0 32.0 24.0 25.0 6.5 28.0 40.0 30.0 28.0 7.0 28.0 55.0 37.0 32.0 7.5 55.0 210.0 250.0 8.0 85.0 300.0 200.0 8.5 9.5 260.0 200.0 9.0 7.0 230.0 180.0 1000 R.P.M. 61 TABLE 8 Test B 2 Conditions: H - Spinning with Flyer 3 inches Top P ulley: Spindle Speed 1000 R.P.M. Fixed, Bottom Pulley: Vibrating Amplitude of Vibration 100 -"inch Spindle #1 #2 #3 #4 3.0 9.0 22.0 20.0 12.0 3.5 10.0 22.0 70.0 15.0 4.0 9.0 20.0 7.0 10.0 4.5 15.0 22.0 8.5 20.0 5.0 12.0 24.0 7.0 10.0 5.5 21.0 26.0 30.0 12.0 6.0 21.0 27.0 20.0 22.0 6.5 27.0 35.0 33.0 26.0 7.0 27.0 32.0 35.0 40.0 7.5 55.0 180.0 60.0 200.0 8.0 75.0 300.0 240.0 8.5 70.0 260.0 240.0 9.0 65.0 240.0 230.0 62 TABLE 9 Test B 3 Conditions: H - Spinning with Flyer 3 inches Top Pulley: Spindle Speed 1000 R.P.M. Fixed; Bottom Pulley: Fixed Amplitude of Vibration 100A-inch Spindle #1 #2 #3 #4 3.0 12.0 22.0 7.0 15.0 3.5 15.0 21.0 6.5 12.0 4.0 15.0 23.0 5.5 8.0 4.5 20.0 28.0 8.0 12.0 5.0 20.0 30.0 8.0 21.0 5.5 23.0 35.0 25.0 26.0 6.0 23.0 35.0 24.0 21.0 6.5 37.0 40.0 29.0 40.0 7.0 32.0 45.0 32.0 30.0 7.5 90.0 400.0 100.0 260.0 8.0 150.0 300.0 - 280.0 8.5 120.0 370.0 ___ 210.0 9.0 100.0 350.0 200.0 P. 63 TABLE 10 Test B4 Conditions: H - Spinning with Flyer 3 inches Top Pulley: Spindle Vibrating; Bottom Pulley: Fixed Amplitude of Vibration 100sM inch peed 1000 R.P.M. Spindle #1 #2 #3 #4 3.0 17.0 20.0 8.0 25.0 3.5 12.0 21.0 20.0 10.0 4.0 10.0 20.0 5.0 15.0 4.5 18.0 22.0 22.0 15.0 5.0 20.0 25.0 25.0 30.0 5.5 21.0 25.0 30.0 25.0 6.0 22.0 25.0 32.0 26.0 6.5 30.0 42.0 75.0 40.0 7.0 30.0 37.0 35.0 45.0 7.5 8.0 200.0 210.0 8.0 85.0 240.0 220.0 8.5 80.0 230.0 180.0 9.0 70.0 220.0 150.0 64 TABLE 11 Test C Conditions: H m Spinning with Flyer 15 inches Top Pulley: Spindle Speed Vibrating; Bottom Pulley: Vibrating Amplitude of Vibration 100 .-" inch Spindle #1 #2 #3 #4 3.0 5.5 9.0 5.0 20.0 3.5 10.0 5.5 4.0 20.0 4.0 15.0 15.0 9.0 35.0 4.5 18.0 15.0 9.0 21.0 5.0 18.0 15.0 18.0 21.0 5.5 21.0 20.0 10.0 25.0 6.0 20.0 20.0 21.0 30.0 6.5 30.0 24.0 22.0 40.0 7.0 32.0 28.0 50.0 40.0 7.5 65.0 45.0 60.0 8.0 80.0 200.0 250.0 8.5 95.0 210.0 220.0 9.0 75.0 150.0 210.0 1000 R.P.M. 65 TABLE 12 Test C 2 Conditions: H = Spinning with Flyer 15 inches Top Pulley: Spindle Speed Fixed; Bottom Pulley: Vibrating Amplitude of Vibration 100-o inch Spindle #1 #2 #3 #4 3.0 3.5 8.5 4.5 25.0 3.5 7.0 5.5 4.0 20.0 4.0 8.0 18.0 5.0 22.0 4.5 20.0 18.0 6.5 25.0 5.0 12.0 20.0 7.0 18.0 5.5 20.0 20.0 7.5 30.0 6.0 21.0 21.0 20.0 26.0 6.5 30.0 30.0 22.0 26.0 7.0 30.0 26.0 22.0 27.0 7.5 60.0 55.0 30.0 35.0 8.0 200.0 85.0 ___ 55.0 8.5 200.0 220.0 - 65.0 9.0 180.0 210.0 - 55.0 1000 R.P.M. 66 TABLE 13 Test C 3 Conditions: H = Spinning with Flyer 15 inches Top Pulley: Spindle Speed 1000 R.P.M. Fixed; Fixed Bottom Pulley: Amplitude of Vibration 100-.einch Spindle #1 #2 #3 #4 3.0 6.0 9.0 4.5 7.0 3.5 20.0 10.0 5.5 6.0 4.0 20.0 18.0 5.0 10.0 4.5 20.0 18.0 7.0 10.0 5.0 20.0 20.0 6.5 10.0 5.5 55.0 20.0 8.0 12.0 6.0 25.0 21.0 9.0 15.0 6.5 35.0 23.0 20.0 25.0 7.0 32.0 29.0 22.0 27.0 7.5 70.0 45.0 29.0 37.0 8.0 90.0 80.0 60.0 8.5 80.0 200.0 90.0 9.0 70.0 180.0 85.0 67 TABLE 14 Test C, Conditions: H - Spinning with Flyer 15 inches Top Pulley: Spindle Speed 1000 R.P.M. Vibrating; Bottom Pulley: Fixed Amplitude of Vibration 100., Spindle #1 #2 #3 inch #4 3.0 5.5 8.0 4.0 6.5 3.5 7.0 8.0 3.0 7.0 4.0 20.0 18.0 5.5 20.0 4.5 15.0 15.0 6.5 25.0 5.0 15.0 22.0 40.0 21.0 5.5 21.0 23.0 25.0 21.0 6.0 21.0 24.0 18.0 23.0 6.5 30.0 30.0 22.0 26.0 7.0 35.0 32.0 22.0 40.0 7.5 55.0 65.0 30.0 57.0 8.0 75.0 200.0 ____ 210.0 8.5 85.0 210.0 240.0 9.0 65.0 180.0 220.0 P 68 TABLE 15 Test D1 Conditions: Spinning with Flyer 10 inches H Top Pulley: Spindle Speed 1000 R.P.M. Vibrating; Bottom Pulley: Vibrating Amplitude of Vibration 100.. Spindle #1 #2 inch #3 #4 3.0 15.0 8.0 10.0 12.0 3.5 15.0 6.0 20.0 12.0 4.0 10.0 8.0 25.0 18.0 4.5 20.0 15.0 25.0 22.0 5.0 21.0 20.0 35.0 30.0 5.5 22.0 20.0 60.0 22.0 6.0 23.0 21.0 35.0 27.0 6.5 27.0 23.0 35.0 30.0 7.0 35.0 27.0 50.0 54.0 7.5 55.0 55.0 65.0 230.0 8.0 90.0 200.0 100.0 250.0 8.5 220.0 150.0 80.0 250.0 9.0 200.0 100.0 70.0 230.0 69 TABLE 16 Test D2 Conditions: Spinning with Flyer 10 inches H Top Pulley: Spindle Speed 1000 R.P.M. Fixed; Bottom Pulley: Vibrating Amplitude of Vibration 100-ou inch Spindle #1 #2 #3 #4 3.0 22.0 12.0 5.5 12.0 3.5 24.0 15.0 5.5 20.0 4.0 26.0 15.0 5.0 21.0 4.5 30.0 18.0 6.5 23.0 5.0 32.0 20.0 6.5 25.0 5.5 30.0 22.0 26.0 27.0 6.0 40.0 22.0 40.0 30.0 6.5 40.0 24.0 40.0 30.0 7.0 45.0 32.0 55.0 40.0 7.5 70.0 58.0 65.0 65.0 8.0 300.0 220.0 85.0 250.0 8.5 300.0 200.0 80.0 260.0 9.0 240.0 180.0 65.0 240.0 70 TABLE 17 Test D3 Conditions: H - Spinning with Flyer 10 inches Top Pulley: Spindle Speed 1000 R.P.M. Fixed; Fixed Bottom Pulley: Amplitude of Vibration 100 -' inch Spindle #1 #2 #3 #4 3.0 9.0 ib.o 5.0 15.0 3.5 12.0 7.0 4.0 10.0 4.0 18.0 6.0 4.0 12.0 4.5 28.0 21.0 6.0 20.0 5.0 35.0 20.0 15.0 23.0 5.5 30.0 21.0 21.0 23.0 6.0 28.0 28.0 20.0 27.0 6.5 35.0 28.0 20.0 27.0 7.0 35.0 35.0 30.0 42.0 7.5 60.0 65.0 60.0 60.0 8.0 95.0 220.0 95.0 24.0 8.5 95.0 230.0 80.0 23.0 9.0 80.0 220.0 60.0 22.0 71 TABLE 18 Test Dg Conditions: H - 10 inches Top Pulley: Spindle Speed 1000 R.P.M. I Spinning with Flyer Vibrating; Bottom Pulley: Fixed Amplitude of Vibration 100 -.4 inch Spindle #1 #2 #3 #4 3.0 10.0 6,0 5.0 18.0 3.5 10.0 8.0 4.0 12.0 4.0 10.0 8.0 4.0 15.0 4.5 20.0 15.0 7.0 20.0 5.0 12.0 21.0 8.0 22.0 5.5 15.0 21.0 9.5 23.0 6.0 18.0 21,0 18.0 25.0 6.5 21.0 23.0 21.0 28.0 7.0 24.0 29.0 24.0 38.0 7.5 37.0 55.0 40.0 80.0 8.0 65.0 210.0 80.0 230.0 8.5 85.0 200.0 70.0 220.0 9.0 60.0 150.0 60.0 210.0 72 TABLE 19 Test E Conditions: H - 14 inches Top Pulley: Spindle Speed 1000 R.P.M. [ No Flyer Vibrating; Bottom Pulley: Vibrating Amplitude of Vibration 100.." inch Spindle #1 #2 #3 #4 3.0 7.0 5.5 7.6 6.0 3.5 8.0 6.5 8.5 8.0 4.0 7.5 7.0 6.5 7.0 4.5 7.0 7.2 8.5 7.0 5.0 8.5 6.0 8.0 7.5 5.5 9.5 6.0 18.0 8.0 6.0 20.0 9.0 20.0 10.0 6.5 21.0 20.0 25.0 20.0 7.0 23.0 22.0 29.0 24.0 7.5 30.0 28.0 50.0 32.0 8.0 60,0 70.0 55.0 3.5 50.0 75.0 65.0 9.0 45.0 65.0 60.0 73 TABLE 20 Test E 2 Conditions: H - No Flyer 14 inches Top Pulley: Spindle Speed 1000 R.P.M. Fixed; Vibrating Bottom Pulley: Amplitude of Vibration 100..uinch Spindle #1 #2 #3 #4 3.0 6.0 4.5 5.0 7.0 3.5 7.0 5.5 6.0 8.0 4.0 6.5 6.0 5.5 8.0 4.5 7.0 6.5 6.0 8.0 5.0 7.0 6.5 6.5 8.5 5.5 8.5 7.5 8.0 9.0 6.0 20.0 9.0 10.0 8.5 6.5 23.0 24.0 21.0 21.0 7.0 21.0 22.0 30.0 22.0 7.5 27.0 28.0 55.0 26.0 8.0 55.0 55.0 ____ 40.0 8.5 70.0 70.0 9.0 60.0 60.0 65.0 ____ 55.0 74 TABLE 21 Test E3 Conditions: H - No Flyer 14 inches Top P ulley: Spindle Speed 1000 R.P.M. Fixed; Bottom Pulley: Fixed Amplitude of Vibration 100,4 inch Spindle #1 #2 #3 #4 3.0 6.5 5.0 4.5 7.0 3.5 5.5 6.0 5.0 7.5 4.0 6.0 6.0 5.5 6.5 4.5 6.0 6.0 5.5 6.5 5.0 5.7 6.5 6.0 7.0 5.5 6.0 6.5 6.2 7.5 6.0 8.5 20.0 9.0 22.0 6.5 20.0 21.0 18.0 24.0 7.0 22.0 20.0 21.0 22.0 7.5 30.0 26.0 45.0 30.0 8.0 60.0 70.0 - 60.0 8.5 80.0 80.0 - 80.0 9.0 65.0 70.0 - 70.0 75 TABLE 22 Test E -4 Conditions: H M No Flyer 14 inches Top Pulley: Spindle Speed 1000 R.P.M. Vibrating; Bottom Pulley: Fixed Amplitude of Vibration 100 Spindle #1 #2 .A #3 inch #4 3.0 5.0 6.5 6.0 7.0 3.5 5.0 7.0 6.5 7.0 4.0 6.5 7.0 7.0 7.5 4.5 6.5 6.0 6.5 6.0 5.0 5.0 6.0 7.0 8.0 5.5 7.0 8.0 7.0 8.0 6.0 8.0 9.0 8.5 10.0 6.5 18.0 22.0 10.0 20.0 7.0 24.0 23.0 20.0 23.0 7.5 28.0 34.0 40.0 25.0 8.0 50.0 65.0 7.0 60.0 8.5 60.0 75.0 7.0 70.0 9.0 55.0 60.0 55.0 76 TABLE 23 Test F1 Conditions: H - No Flyer 17 inches Top Pulley: Spindle Speed 1000 R.P.M. Vibrating; Botton Pulley: Vibrating Amplitude of Vibration 100 Ainch #1 Spindle nd e #1 3.0 3.0 #2 23 3.0 3.5 3.0 3.0 2.6 3.5 4.0 4.0 4.0 3.5 5.0 4.5 3.5 4.0 3.5 6.0 5.0 4.5 5.0 3.5 6.5 5.5 4.0 4.0 4.0 6.5 6.0 5.0 6.0 5.5 8.5 6.5 5.5 6.0 7.5 21.0 7.0 7.0 20.0 20.0 22.0 7.5 25.0 21.0 24.0 25.0 8.0 27.0 30.0 33.0 32.0 8.5 35.0 50.0 37.0 57.0 9.0 35.0 50.0 37.0 50.0 , #3 #4 2.8 3.5 Flop" 77 TABLE 24 Test F 2 Conditions: H - No Flyer 17 inches Top Pulley: Spindle Fixed; Bottom Pulley: Vibrating Amplitude of Vibration 10O- inch Speed 1000 R.P.M. Spindle #1 #2 #3 #4 3.0 3.0 4.0 3.0 4.5 3.5 3.5 4.5 3.0 4.5 4.0 4.0 4.5 3.5 5.0 4.5 4.0 4.5 4.0 5.5 5.0 4.5 5.0 4.5 7.0 5.5 4.5 5.5 4.5 6.5 6.0 5.0 6.0 7.0 7.0 6.5 7.0 8.0 9.0 20.0 7.0 7.5 8.5 20.0 20.0 7.5 12.0 21.0 23.0 23.0 8.0 20.0 24.0 35.0 30.0 8.5 23.0 32.0 37.0 40.0 9.0 21.0 27.0 32.0 35.0 78 TABLE 25 Test F 3 Conditions: H - No Flyer 17 inches Top Pulley: Spindle Speed 1000 R.P.M. Fixed; Bottom Pulley: Fixed Amplitude of Vibration 100 -. inch Spindle #1 #2 #3 #4 3.0 3.2 3.0 3.5 5.0 3.5 3.5 4.0 3.5 5.0 4.0 3.8 4.5 3.0 4.5 4.5 3.8 3.5 4.0 4.2 5.0 4.0 5.0 4.0 6.0 5.5 3.5 6.0 4.0 6.0 6.0 6.0 6.0 6.0 7.0 6.5 7.0 7.5 8.0 20.0 7.0 8.0 9.5 21.0 23.0 7.5 9.0 21.0 25.0 25.0 8.0 21.0 30.0 35.0 40.0 8.5 26.0 40.0 45.0 55.0 9.0 25.0 40.0 40.0 50.0 79 TABLE 26 Test F 4 Conditions: H - No Flyer 17 inches Top Pulley: Spindle Speed 1000 R.P.M. Vibrating; Bottom Pulley: Fixed Amplitude of Vibration 10O 4tinch Spindle #1 #2 #3 #4 3.0 3.5 3.0 3.5 3.5 3.5 3.5 3.5 3.5 4.0 4.0 4.0 4.0 4.5 5.0 4.5 4.5 4.5 4.6 5.0 5.0 5.0 5.5 4.0 7.0 5.5 4.0 5.0 4.5 6.5 6.0 5.5 6.5 6.0 8.0 6.5 6.0 6.5 9.0 9.5 7.0 8.0 18.0 22.0 23.0 7.5 18.0 23.0 26.0 26.0 8.0 22.0 27.0 40.0 40.0 8.5 35.0 45.0 37.0 60.0 9.0 35.0 45.0 35.0 50.0 80 TABLE 27 Conditions: H - No Flyer 15 inches Top Pulley: Spindle Vibrating; Bottom Pulley: Vibrating Amplitude of Vibration 100-4 inch Speed 1000 R.P.M. Spindle #1 #2 #3 #4 3.0 6.0 5.0 4.2 5.0 3.5 7.0 4.0 4.2 3.5 4.0 7.0 6.0 4.5 5.0 4.5 7.0 7.0 6.0 6.0 5.0 20.0 9.0 6.5 7.0 5.5 21.0 9.0 7.0 8.5 6.0 30.0 9.5 8.0 9.0 6.5 48.0 15.0 9.0 18.0 7.0 30.0 21.0 20.0 21.0 7.5 37.0 45.0 30.0 28.0 8.0 50.0 40.0 37.0 45.0 8.5 70.0 80.0 30.0 60.0 9.0 60.0 60.0 28.0 50.0 81 TABLE 28 Test G Conditions: No Flyer 15 inches H Top Pulley: Spindle Speed 1000 R.P.M. Fixed; Bottom Pulley: Vibrating Amplitude of Vibration 100 Atinch Spindle #1 #2 #3 #4 3.0 6.0 5.5 4.0 5.0 3.5 7.0 5.5 4.2 5.0 4.0 8.0 5.0 4.5 5.2 4.5 8.5 6.0 6.5 6.0 5.0 9.0 7.0 7.0 6.0 5.5 25.0 20.0 12.0 8.0 6.0 28.0 18.0 18.0 15.0 6.5 35.0 15.0 18.0 18.0 7.0 40.0 18.0 20.0 20.0 7.5 55.0 24.0 30.0 26.0 8.0 70.0 32.0 42.0 42.0 8.5 80.0 80.0 45.0 60.0 9.0 60.0 70.0 30.0 55.0 82 TABLE 29 Test G3 Conditions: H - No Flyer 15 inches Top Pulley: Spindle Speed 1000 R.P.M. Fixed; Fixed Bottom Pulley: Amplitude of Vibration 100/ Spindle #1 #2 #3 inch #4 3.0 7.0 5.0 4.5 5.0 3.5 5.0 4.5 4.5 4.5 4.0 6.0 5.0 5.0 5.5 4.5 8.0 5.0 6.0 6.0 5.0 23.0 7.5 7.5 7.0 5.5 50.0 15.0 20.0 12.0 6.0 55.0 20.0 18.0 15.0 6.5 35.0 15.0 20.0 20.0 7.0 35.0 18.0 23.0 20.0 7.5 42.0 21.0 35.0 27.0 8.0 40.0 32.0 40.0 50.0 8.5 70,0 70.0 35.0 70.0 9.0 60.0 60.0 33.0 65.0 83 TABLE 30 Test G Conditions: H - No Flyer 15 inches Top Pulley: Spindle Speed 1000 R.P.M. Vibrating; Bottom Pulley: Fixed Amplitude of Vibration 100,a inch Spindle #1 #2 #3 #4 3.0 6.0 6.0 5.5 4.5 3.5 4.0 4.5 5.5 5.0 4.0 5.5 6.0 6.0 5.5 4.5 6.5 5.5 9.0 6.0 5.0 8.0 7.0 7.0 8.0 5.5 8.5 8.0 9.5 8.0 6.0 9.0 9.0 12.0 9.0 6.5 8.0 8.0 18.0 15.0 7.0 12.0 25.0 23.0 21.0 7.5 23.0 30.0 40.0 25.0 8.0 37.0 40.0 40.0 42.0 8.5 36.0 60.0 38.0 60.0 9.0 30.0 50.0 35.0 50.0 84 TABLE 31 Test H Vibration of Main Shaft Spindle Speed r.p.m. Shaft Speed r.p.m. Amplitude of Vibration 100 < in. 1000 186 4.0 1500 279 6.8 2000 372 24.0 2500 465 26.0 3000 558 31.0 3500 651 39.0 4000 744 59.0 4500 847 87.0 5000 930 230.0 5500 1023 200.0 6000 1116 64.0 6500 1209 42.0 7000 1302 36.0 7500 1395 33.0 8000 1488 34.0 8500 1581 360.0 9000 1674 370.0 9500 1763 300.0 10000 1860 280.0 85 TABLE 32 Experimental Results R.P.M. H Test I Spindle # To gm Dmaxi 3.0 5000 1 84 5.00 10.5 5000 1 110 5.80 14.0 5000 1 160 6.27 3.0 5000 3 - 5.00 10.5 5000 3 156 5.80 14.0 5000 3 180 6.27 3.0 5000 4 50 5.00 10.5 5000 4 60 5.80 14.5 5000 4 70 6.27 TABLE 33 ExperimenLal Results H R.P.M. Text J Spindle # Togm Dmax" 6000 1 206 5.00 10.5 6000 1 276 5.82 14.0 6000 1 306 6.15 3.0 6000 3 - 10.5 6000 3 254 5.82 14.0 6000 3 310 6.15 3.0 6000 4 76 5.00 10.5 6000 4 80 5.82 14.0 6000 4 94 6.15 - 3.0 86 TABLE 34 Experimental results H R.P.M. 13.0 5000 15.0 Test K Spindle # Togm. Dmax" 1 140 5.40 5000 1 160 5.72 16.5 5000 1 194 6.08 13.0 5000 3 176 5.40 15.0 5000 3 186 5.72 16.5 5000 3 390 6.08 13.0 5000 4 171 5.40 15.0 5000 4 178 5.72 16.5 5000 4 180 6.08 To gm. Dmax TABLE 35 Experimental results Test L H R.P.M. 13.0 6000 1 286 5.40 15.0 6000 1 350 5.50 16.5 6000 1 374 5.92 13.0 6000 3 360 5.40 15.0 6000 3 434 5.50 16.5 6000 3 440 5.90 13.0 6000 4 400 5.40 15.0 6000 4 416 5.50 16.5 6000 4 434 5.92 Spindle # 87 VII. CALCUIATIONS AND RESULTS 88 A. VIBRATION Calculation of natural frequencies for different parts of the machine. Spindle #1 has the construction Spindle #1 a shown in Fig. 18 . In our calculation, here, we shall 1. assume that the aluminum sleeve has no effect on the moment of inertia of the shaft since it is most rigidly fixed to it. This sleeve can be considered as an additional weight carried by the spindle. However, we shall neglect its weight as compared to the weight of the spindle. From equation 16, the natural frequency of the spindle is given by V A for the spindle we have L - 11" E = 3 x 10 7 lb/inch 2 for steel I inch __ 2 slug/inch3 032.28. cl - A d - - 4 7 - inch 2 inch Substit u ti ng these values we get 0 or (A - 600 cycle/sec. - 36,000 r.p.m. 89 2. The natural frequency of a simply Main Shaft: supported shaft is given by: where 3 x 10 E I - D - 64 1.5 lb/inch 2 inch inch IiYgL inch 2 A 56 L - 32.2 inch 12 slug/inch giving (A)PI or n 28 M cycle/sec. 28 x 60 = 1680 cycle/min. Actually the natural frequency of the shaft will be decreased, due to the weight of the pulleys and to the tension force in the belt. B. TENSION The data of test L was chosen for purposes of comparisen between the experimental and theoretical results. 90 Test L Experimental Data - 32.5 cm - 2001f 2A = Dnmax To - 400 gm. H rad/sec. 13.7 cm - Theoretical Evaluation Equation 10 gives 00(A3 +.M~.Cv~O( + . 7M j taking 5 Cl - 0.5 - 0.4 (assumed as did De Barr) - a 5.62 x 10-6 gm/cm. m R - M sin v Ce 6.25 cm radius of bobbin sinO( d 1.7 radius of ring 2.5 a = 0.4 - 0.5 x 10- 2 cm - 6 - 1.2 x 10-3 gm/cm3 - MR W2- =2..75 t.1 + r 91 Sin o< cos 7 + c. cos << .Scc C Sin o( COB 3 C 1 fa d A 3 - 0.713 gm. - 716 gm. - 52 gm. 4cs< H 4 R sinoc - %jm U) 2 R T 0 - 14 gm. 398 gm. The results are tabulated in Tables 36, 37 and 38. 92 TABLE 36 Spindle #1 Experimental H Dmax To gms. 5UUU 16000 9 5000 6000 rp.m. r.p.m rn . r.D.m. r.p.m. 3 10.5 14.5 84 110 160 206 276 360 5.0 5.8 6.3 13.0 15.0 16.5 140 160 190 360 434 440 5.4 5.7 6.1 . . 4- Theoretical To 5000 6000 rnpm . r 5.00 5.82 6.20 268 283 294 386 409 424 5.40 5.50 5.90 284 292 299 398 409 426 TABLE 37 3 - - - - - Spindle #3 10.5 14.5 156 180 254 310 5.8 6.3 5.82 6.20 283 294 409 424 13.0 15.0 16.5 176 186 390 360 434 440 5.4 5.7 6.1 5.40 5.50 5.90 284 292 299 398 409 426 TABLE 38 Spindle #4 3 10.5 14.5 50 60 70 76 80 94 5.0 5.8 6.3 5.00 5.82 6.20 268 283 294 386 409 424 13.0 15.0 16.5 171 178 180 400 416 434 5.4 5.7 6.1 5.40 5.50 5.90 284 292 299 396 409 426 m 93 VIII. DISCUSSION 94 In the spinning frame, certain parts are considered as sources of noise and vibration. These parts may be rotating, reciprocating, or stationary. The parts which may produce noise and vibrations are: 1. Gear trains and driving motor 2. Guiding pulleys 3. Spindles 4. Flyer 5. Main shaft 6. Yarn guide 7. Ring rail 8. Spindle rail 9. The lever of spindle brake. As a part of this work, we shall discuss the effect of each element on the performance of the machine. 1. Gear trains and driving motor. Most of the gears in the frame are running at slow speeds, which does not exceed 1800 r.p.m. All the gears in the frame are mounted on either a short cantelever supported shaft. shaft or a short simply For this reason, these shafts have very high natural frequencies. In othei words we can say that the vibration of the gear trains does not affect the frame to a significant degree. 95 2. Guiding pulleys. The function of the guiding pulleys is to guide the belts used in driving the spindles. These pulleys are attached to springs to allow for the reciprocating motions of the spindles. All the test showed three peaks of spindle vibrations. The first of these peaks is eliminated after fixing of the top guiding pulley of the frame (see Fig. 21). The effect of this top pulley was significant only in the low speed range, which is not a desirable working speed. On the other hand when the bottom pulley was fixed, no significant change in the amplitude of vibration took place. 3. Spindles. Three out of the four spindles tested namely #1, #2, and #4 did not differ in their behavior. Spindle #3 while spinning with the flyer did not lend itself to use at speeds higher than 7000 r.p.m. This was due to the fact that the yarn running through the flyer introduces a force on the top of the bobbin which in more conventional spinning is taken up at the pigtail guide fixed directly to the frame. As the speed starts to increase this force increases. Because spindle #3 is longer than the other three, the bending moment exerted by the flyer force is higher and its deflection became significantly greater causing severe vibration at high speeds. 96 4. Flyer. As said before the flyer introduces a new force to the bobbin top. This force is proportional to the yarn tension at the apex of the balloon and depends on: a. Spindle speed b. Balloon height c. Weight of traveller d. Yarn count The force will vary as the square of speed, as the balloon height, traveller weight and as the count of the yarn spun. The tests at high speeds showed the vibration amplitude with the flyer to be 10 times that with no flyer. 5. Main shaft. The tests showed this shaft be the main source of exitation for the entire spinning frame. It was concluded that the different parts of the machine were forced to vibrate by the dynamic forces exerted by the shaft. This conclusion followed from the fact that the vibrations of the spindle went through a peak at a frequency corresponding to the critical speed of the shaft. The vibration of the shaft may be related tc Tension ir Belts (see Fig. 21) As the spindle rail moves up and down the inclination of the belts changes, resulting in a change of the vertical and lateral components acting en the shaft. The change of these 97 components will change the defection in the shaft and its natural frequencies. 6. Yarn guide. (Used without the flyer). The yarn guide is a hinged plate with a slot to provide a space for the yarn. The guide is fastened and its hinged end to the frame and thus it vibrates with the frame. It also vibrates with the impact of yarn slubs. 7. Ring rail. The ring rail carries the traveller on the ring and it is not rigidly connected to the frame. It is carried by the frame by means of steel wires, which allow for its vertical reciprocating motion. The vibration of the ring rail may be related to: 8. a. Eccentricity of spindle b. Vibration of traveller c. Change in yarn tension d. Frame vibration e. Its natural vibrations Spindle rail. The spindle rail significantly affects the behavior of the spindle - bobbin combination. Its vibration is transmitted to the spindle. As is the case for the ring rail it is also not rigidly connected to the frame but is also carried by steel ropes to provide vertical reciprocating motions for the spindles. The vertical 98 reciprocation of the ring rail provides a short term winding coverage of the bobbin, while the reciprocation of the spindle rail covers a wider range at a longer interval to ensure completion of the bobbin package wind. The factors affecting the vibration of the spindle rail are: a. Yarn tension b. Eccentricity of spindle in ring c. Spindle vibration d. Frame vibration e Its own natural vibration When the spindle rail vibrates it increases the eccentricity of the spindles in the rings. As this eccentricity changes, the tenion (force on spindle) will change, resulting a change in the defflection of the spindle. 9. Lever of the spindle brakes. The lever brake is provided for slowing down the spindle for doffing or for repairing broken ends is free to oscillate in its normal position. It is very light compared to the other parts of the spindle, but at high speeds this lever vibrates severely producingan objectionable noise. 99 Fig. 26 shows the relationship between the vibration amplitude of the shaft and its rotational speed. From the graph it is clear that the shaft has twc critical speeds. These two critical speeds correspond to 5000 and 9000 r.p.m. of spindle speed. The vibration as measured at the spindle rail was also found to have two peaks at these speeds, thus pointing to the shaft as a main source of spindle vibration. The tests alse showed that the flyer is another source of vibration because the magnitude of the vibration amplitude with the flyer was found to be 10 times that without the flyer. The results of these tests are plotted in appendix 2 (Figs. 31 to 56). Tensions After a close look at our results we found that the factors affecting the yarn tension are: 1. Spindle speed 2. Balloon height 3. Yarn size 4. Traveller size 5. Eccentricity of spindle in ring 6. Bobbin diameter 100 In our work we kept the items #3, #4, and #5 unchanged. The tests were run at different spindle speeds, balloon heights and bobbin diameters. In some tests specially when using spindle #3 the eccentricity was noticed to be larger than usual. In that case the test signals appeared to have the spindle frequency which suggests that for this case the eccentricity was the dominant factor. In this case the bobbin diameter may be considered as if it were changing from maximum to minimum during each spindle revolution, instead of remaining constant as in the case of concentricity. It was also shown that as the bobbin diameter increases the yarn tension decreases, while it increases as the balloon height increases. The tests showed that the tension was increased with the square of the spindle speed. The tension which was given by equation 10 also depends to a great extent onA and chapter #3. a, as defined in In our calculation for the theoretical values of the tension we used assumed data 5 for these two factors. The difference between theoretical yarn tension and the experimental values reported in Tables 36, 37 and 38 may be due to an error in these assumed values. It is noticed that in the case of no flyer the change 101 in balloon height was in a small range (13" to 16.5"). While on the other hand when using the flyer the change was very wide (3" to 15"). This means that the variation in the yarn tension with flyer will have a larger range than that without the flyer for corresponding speeds. This is taken adeount in the design of the machine through speed control (i.e. reductioL at larger balloon heights and increase at low balloon heights). All the tests showed that the tension measured in the case of the flyer is smoother and more regular than that measured without the flyer. This is due to the fact that the positioni and the geometry of the flyer (relative to the pigtail guide) decreases dhc lateral vibration of the yarn. The tests also showed spindle #4 to be the most applicable one at high speeds, while using the flyer. The tests on spindle #4 showed a nearly constant tension, with minimum irregularities. The experimental data obtained, ate plotted in Fig. 27 which represents the yarn tension as a function of balloon height. Figure 28 Tension vs. Balloon Height I i Spindle, #1 Spindle #3 I- 0 Spindle #4 44*11 #0I- 4,c0F 9 T 2ool- - 20 K /Oc4- I 8 0 I 0 I I I 30 40 gO I 1 I __ 0, 40 50 p 10 0 I I 30 40 Balloon Height (cms .) A With flyer aZ 5000 r.p.m. A Without flyer at 5000 r.p.m. MWith flyer at 6000 r.p.m. Without lyer at 6000 r.p.m. 8 103 IX . CONCLUSIONS 104 It was found that experimental average tension data obtained during spinning on a conventional woolen frame, correspond to the theoretical expressions reported by De Barr. The exact solution of these expressions was quite long, and needs quite a number of factors to be determined but these were assumed for the calculations at hand. In most cases the theoretical values of the tension exceeded the experimental values. This was surprising because it would be expected that the opposite would be true, that is, that the experimental tension values should be greater than the theoretical ones due to the frictional forces at the yarn guide, at the flyer, at the guiding ring and at the pulley system of the tensiometer. These forces are not accounted for in the De Barr equations. It was noticed on short balloon (H - 3"), that the diameter of the yarn configuration never reached a maximum. Actually an imaginary maximum diameter forms at an imaginary height below the ring for such cases. The fact that theoretical tension values were higher than the experimental ones may be due to errors in the values of the coefficients of friction, which were assumed in computing these tensions. In most tests spindle #2 had the higher amplitude 105 of vibration while spindle #3 did not lend itself to work at high speed when using the flyer. It was found that spindles #1 and #4 are the most workable spindles and that there was no significant difference between them. The causes of vibrations in the machine were found to be: 1. The Main Shaft. As discussed before, this shaft is the principal cause of spindle vibration. It was noticed during high speed operation that this shaft actually seemed to shake the whole frame. The critical speeds of the shaft lie within the workable speed range of the frame, and therefore provides severe limitation on the working range of the frame. 2. The Flyer. The flyer was found to be a second source of vibration in the spindle. The tests showed that the vibration amplitude with the flyer were far larger than those obtained without the flyer. This was due to the force exerted by the thread on the flyer and in turn by the flyer to the top of the bobbin. This force increases the deflection of the spindle-bobbin combination causing it to vibrate with excessive amplitude at high speeds. The third cause of vibration is the flexible structure of both the ring and spindle rails. 106 X. RECOMMENDATION FOR FRAME IMPROVEMENTS -A 107 To improve the frame we suggest the following: 1. The main shaft should be changed to a larger, hollow shaft to increase its critical speed. Fig. 29 shows a cross-section of the suggested shaft. The critical speed of such a shaft should reach (3500 r.p.m.) corresponding to spindle speeds of 20,000 r.p.m. The shaft should be closely alligned in its bearings. 2. If the above change is not sufficient to permit continuous high speed spinning the flyer should be removed from the top of the bobbin. The yarn guide alone may satisfy the spinning requirements, but it would be much better if the flyer is placed between the yarn guide and the top of the bobbin. This will ensure retention of the benefits of the flyer without introducing its disadvantages. 3. Both the ring and spindle rails should have stiffer constructions and support. The spindle rail instead of having a single flange can have a double flanged rail (Fig. 30) and be supported. In such a way that its motion is restrained in a vertical direction translation. The ring rail should also be supported rigidly so that it will not be affected by the tension forces exerted on it through the traveller. 4. The spindle brake levers should be held in such a position as to stop their oscillation. This can be done 108 by using a spring to force the lever into a single position when not in use. 5. The last suggestion is to centre the spindle within the ring rail to reduce the extreme changes in yarn tension (during each spindle rotation) due to eccentricity. Figure 29 Cross-section of suggested shaft Spindle I 109 Housing 4 I LII- 3 Brake seat i "I It' -~ 4 I I // - -1--.h N .Ap Aluminum / channels 1 .- -I 1 .4.w,/ _______I I Fiue 3 0 Diagrametic sketch of suggested spindle rail scale full size. 110 APPENDIX NO. 1 Use of the Spinning Frame for Further Engineering Studies r 111 The present spinning frame can be used as an educational subject in many different ways. It is highly desirable for a student to become familiar with the spinning equipment and to learn the theory of spinning through actual experiments. The tensiometer may be used together with other equipments described in this thesis to meaure yarns tensions under varying spinning conditions and compare them with the values obtained theoretically. Such data can be used to check the theoretical expressions for tension proposed by several authors. The frame can also be used to confirm equations for the balloon shape and for the yarn tension in the balloon by the Cappello method. In comparing the results of future tests with the theoretical computed data, it would be desirable to determine more accurately the coefficient of frictions between the yarn and different parts of the frame. Also it would be of great value to determine accurately all the different parameters of equation 10, e.g. the angle of warp of yarn on traveller the air drag coefficient and the maximum balloon diameter. Finally the role of the yarn properties as they interact with the traveller performance and the contact guides should be taken into account. 112 APPENDIX NO. 2 Plott of Vibration Data 113 o Spindle #1 Spindle #2 A Spindle #3 a .30 * - -o Spindle #4 0 '0 -4 *r4 0 44J /0 A - 5 Spindle speed 1000 r.p.m. Figure 31 Test A 1 114 o Spindle #1 30 - Spindle #2 A Spindle #3 A Spindle #4 25 20 04 04 -0 0 ar4 *4 0 Spindle speed 1000 r.p.m. Figure 32 Test A 2 115 o Spindle #1 130 _ Spindle #2 A Spindle #3 + Spindle #4 15 - G4 0 ,0 4 S35 7 Spindle speed 1000 r.p.m. Figure 33 Test A 3 9 116 o 30 _ Spindle #1 Spindle #2 A Spindle #3 + Spindle #4 0 zo0 '0 ,1r4 r14 /r-- 0 4 > /0 ~Test A Spindle speed 1000 r.p.m. Figure 34 Test A4 117 I I o Spindle #1 * Spindle #2 230 .- 14o - A Spindle #3 + Spindle #4 U r14 0 0 o4) *A 5 .3 7 p5 Spindle speed 1000 r.p.m. Figure 35 Test B, 9 118 7-'- I I i I - I I Sp nole Iri A. Spindle #2 A Spindle #3 230 I- /Or5 7 I 4- Spindle #4 @1-4 r-4 4-) *A 0 140 4-- 0,-I - Sl 5 7 3 Spindle speed 1000 r.p.m. Figure 36 Test B 2 9 P 119 o Spindle #1 * Spindle #2 A Spindle #3 230 + Spindle #4 - /85- 0 r /40 *1-4 95 '- 13 15 7 Spindle speed 1000 r.p.m. Test B 3 120 -i I I I I I I I I | I I v Spindle #1 0 Spindle #2 & Spindle #3 + Spindle #4 - 230 is I;lI 41 "14 4010 "4 *4 95 50 5 3 '5Spindle speed 1000 I.p.m. Figure 38 Test D 4 9 121 o Spindle #1 o Spindle #2 A Spindle #3 C) - + Spindle #4 ,230 /85- 0 0 9-4 4) *v-- 0 e-A 4-) cr4 96 50 73 Spindle speed 1000 r.p.m. Figure 39 Test C 1 ' Spindle # 122 o Spindle #1 * Spindle #2 A Spindle #3 230 _ Spindle #4 0 r4 '0 o4- r14 R 0 *r4 .0 Fig/404 959 ~Spindle speed 1000 r.p.m. Figure 40 Test C2 123 Spindle #1 o Spindle #2 230-- U Spindle #3 A Spindle #4 .r4 "4) .o 9.5 .1-4 50, .1-3 Spindle speed 1000r.p.m. Figure 41 Test C3 124 o Spindle #1 v Spindle #2 A Spindle #3 A Spindle #4 /I85 - *-4 0 0 41) *r4 1 40 -... H so 3 Ipindle speed 1000r. p.m.3 Figure 42 Test C4 125 l 2 7S * Spindle #1 Spindle #2 Spindle #3 + Spindle #4 0- r4/5 0 0 "4 /4 140 ,,r4 95' 3 5spindle speed 1000 7 r.p.m. Figure 4 Test D 126 o Spindle #1 * Spindle #2 A Spindle #3 #4 Z3 Spindle i0 C) 4 "4 v-4 /40 04 Cr 4j *14 50 '3 5 Spindle speed 10007 r.p.m. Figure 44 Test D2 S 127 Z75. Spindle IVl Spindle #2 A Spindle #3 280 - + Spindle #4 *14 ~'Its v-4 "4 r-4 0 *r4 "4i > - 04 5 Spindle speed 1000 7rpm. Figure 45 Test D3 128 o Spindle #1 a Spindle #2 230 - a Spindle #3 x Spindle #4 Spindle #4 C: r~4 4) "4r14 Ra o40 0 4-i 1.0 395 3 $ Spindle speed 1000 7r.p.m. Figure 46 Test D o Spindle #1 a Spindle #2 70 A Spindle #3 + Spindle #4 60 *r4 40 - ~- 40 0 - 50 4/- ?o /0 SpindLe speed 1000 r.p.m.7 Figure 47 TO&C - v 130 - 70 o Spindle #1 a Spindle #2 A Spindle #3 + Spindle #4 60 50 oC # Spidle 402 -r-4 4-i *r1 '- 30 20 k- /O F I 0 '3 5 7 Spindle speed 1000 r.p.m. Figure 48 Timh ca-I I 9 0 O Spindle #1 70 * Spindle #2 Spindle #3 + Spindle #4 60 50 IC) 0 40 k- J '-4 ,a ,30 I- 20 10 1- 0 3 7 5 Spindle speed 1000 r.p~m. FIgure 49 *1..- ", . J-j 132 70 o a k x Spindle Spindle Spindle Spindle #1 #2 #3 #4 60 00 r4 r4 0 v-4 co 0 *r4 > 30 Ttt 0 Spindle speed 1000 r~p~m. Figure 50 Test E 133 o Spindle #1 o Spindle #2 70 A Spindle #3 + Spindle #4 60 0 r-4 50 4o T-4 it Cd ,0 40 20 3 3 Spindle speed 1000 7r.p.m. Figure 51 Test F1 134 6 -o Spindle #1 * Spindle #2 A Spindle #3 + Spindle #4 50 40- s~o 0 '*0 ,0 0 I - 7 5 Spindle speed 1000 r.p.m. Figure 52 Test F2 --- 8 135 o Spindle #1 I Spindle #2 A Spindle #3 + Spindle #4 50- *r#4 o40 0 '-4 4) . SH 4 0 20 3 A79 Spindle speed 1000 r.p.m. Fioyurc 53 Test F 3 A 136 a 60 Spindle #1 5 Spindle #2 A Spindle #3 + Spindle #4 601- .f.4 40 k- r4 30 10 _____________________I 20 I- . 4J /0 0 3 5 p7 Spindle speed 1000 r.p.m. Figure 54 Test F 4 19 137 70 0 Spindle #1 a Spindle #2 A Spindle #3 + Spindle #4 60 u 50 14, 0 -I 0 4 o4 0 10 30 -4 20 '3 79 - Spindle speed 1000 r.p.m. Figure 55 Test G, 138 Spindle #1 Spindle #2 70. Spindle #3 Spindle #4 60- 44 0 '4 44 "-4 0 "41 3 5 6 7 Spindle speed 1000 r.p.m. Figure 56 Test GI, 8 9 139 Spindle #1 70 - * Spindle #2 Spindle #3 Spindle #4 50- 0 0 -If 4) .1-4 r-4 0 4 *rI 3 sn Spindle speed 1000 r.p.m. Figure 57 T..ta - r- 140 o Spindle #1 * Spindle #2 x Spindle #3 Spindle #4 So r4O 00 r4 S30 0 01.4 4-i "14 I) Spindle speed 1000 r.p.m. Figure 58 Test G4 141 APPENDIX NO. 3 Typical Signals of Yarn Tension and Balloon Configuration 142 In all pictures of yarn tension (Figures 59 to 70), the signals are arranged in the following order: Spindle #1 Spindle #3 Spindle #4 143 Test I No = 5000 r.p.m. with flyer Figure 59 H = Spindles #1, 3"1 and 4 IU L -I i~T~ 3 -~ I H = 10.5" Spindles #1,3 and 4 Figure 61 H - Figure 60 14.0" Spindles #1,3 and 4 144 Test J N 6000 r.p.m. r~nrrrrrrnr~ Figure 62 & Spindles #1, H rrxATTTT = 3" EU.LE J 1 Figure 63 Spindles #1,3 and 4 H 4 10.5" Figure 64 Spindles #1, H = 3 and 4 14.0" 145 Test K N 5000 r.p.m. no flyer = Figure 65 Spindles #1, 3 and 4 13.0" H I I Figure 66 Spindles #1, 3 and 4 H=15. 0" ~z~JLi~ - I Figure 67 Spindles Il, 3 and 4 H = 16.5" LI :LIa 146 Test L N = 6000 r.p.m. no flyer Figure 68 Spindles- #1, 3 & 4 H = - 13. 0" - rT~~ I: UhLjt. LA2 Li a. a x & Figure 70 Figure 69 Spindles #1, H 3 and 4 15.0" Spindles j1,3 and 4 H = 16.5 147 Figure 71 Test I H - 3" N - 5000 r.p.m. Spinning with Flyer 148 Figure 72 Test I H - 10.5" N - Spinning with Flyer 5000 r.p.m. 149 Figure 73 Test I H - 14'' N - 5000 r.p.m. Spinning with Flyer 150 Test K H - 13.0" N - 5000 r.p.m. Spinning without Flyer 151 Figure 75 Test K H - 15" N - 5000 r.p.m. Spinning without Flyer 152 Figure 76 Test K H - 16.5" N - 5000 r.p.m. Spinning without Flyer - m ~-~------------------------- I 153 REFERENCES General 1. Gross, E. Erwin, "Measurement of Vibration" Radio Company, Massachusetts, 1955. 2. Kyros, William, "Investigation of ring spinning with special reference to yarn tensions and their relationship to balloon diameters", M.I.T. unpublished, S.M. Thesis, 1957. 3. Grishin, P.F., "Balloon Control", Platte Bulletin, Oldam, England, 1956. 4. Capello, A., "The Spinning Balloon", T.I.J. Vol. 49 1958. 5. "A Descriptive Account of Yarn Tensions De Barr, A.E., and Balloon Shapes in Ring Spinning", T.I.J., Vol. 49, 1958. 6. "Some Observations on the Wroe, D. and Nissan, A.H., Vibration and Whirling of Continuously Loaded Spindles" T.R.J. Vol. 29, 1959. 7. Den Hartog, J.P., "Mechanical Vibration" 4th Ed., McGraw-Hill Book Company, Inc., 1956. 8. Dunkerley, J.,"Phil. Trans. Royal Society", A-185, 279 (1894). 9. 10. Von Bergen and Mauersberger, "American Vool Handbook" 2nd Ed., Textile Book Publishers, Inc., 1948. Schwarz, E.R., "Basic Actions as Approach to Textile Processing", T.R.J. Vol. 28, 1958.