E
12
®
RINGFEDER Locking Assemblies
00
Catalogue
RfN 7012
For highly-stressed shaft-hub
connections and high machining tolerances
RINGFEDER Products are available from MARYLAND METRICS
P.O. Box 261 Owings Mills, MD 21117 USA email: sales@mdmetric.com web: http://mdmetric.com
phones: (410)358-3130 (800)638-1830 faxes: (410)358-3142 (800)872-9329
Locking Connections
RINGFEDER® Locking Assemblies RfN 7012
Please note that our guarantee refers to our products only. Because of the unlimited number of applications and all different types of machines, it is
not possible for our engineers to know all factors
that may affect or change the technical data or our
products.
This publication may not be reproduced, either partly or wholly, without the source being quoted.
We reserve the right to modify design by way of
technical improvement.
Locking Connections
Certified by DIN EN ISO 9001 and VDA 6.1
RINGFEDER Products are available from MARYLAND METRICS
P.O. Box 261 Owings Mills, MD 21117 USA email: sales@mdmetric.com web: http://mdmetric.com
phones: (410)358-3130 (800)638-1830 faxes: (410)358-3142 (800)872-9329
Index
Page
Characteristics
..........................................................................................4
Dimension table for Locking Assemblies RfN 7012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Hub outside diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Calculations:
Locking Assemblies RfN 7012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Hollow shaft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Fitting and removing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Hints on construction – Typical constructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
The ABC of the Locking Assemblies RfN 7012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Torque wrenches and accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Strength values: Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Cast steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
ISO-Table of tolerances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Mounting suggestions, required data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3
RINGFEDER® Locking Assemblies RfN 7012
For highly-stressed shaft-hub connections
The shrink fit is unsurpassable. No other shaft-hub connections
can offer anywhere near the same performance regarding
fatigue strength under alternating torsional stresses. These fits
are nevertheless rare, as they call for involved calculations,
extremely close machining tolerances, cause considerable
trouble when fitting and removing the parts in question, and
give rise to problems during repair work (exchangeability,
adjustments, centering, etc.).
The locking Assembly RINGFEDER Connections is a shrink fit
- a shrink fit of special kind.
CHARACTERISTICS
Fig. 1 · Locking Assembly RINGFEDER® RfN 7012
TRANSMISSION OF HIGH PERIPHERAL FORCES
Several Locking Assemblies RfN 7012 can be used in series.
The transmissible torques and axial loads are added
(see page 7)
OPTIMUM DEPENDABILITY
We guarantee the torque/axial load transmission values as given
in this publication, regardless of whether the connection is subjected to static, dynamic or impact loads. However, the values
given in this catalogue must not be exceeded.
SIMPLIFIED MANUFACTURES
Locking Assemblies RfN 7012 can bridge large clearances
between k 11 and h 11 resp. N 11 and H 11 are possible (cf.
Page 7).
EASY EXCHANGEABILITY
Locking Assemblies RfN 7012 bridge large clearances and need
no stops or other mechanical devices of this type. In contrast
to all other shafthub connections, close machining tolerances
are unnecessary.
EASY MOUNTING
The temperature difference between shaft and hub for shrinkage
fits is eliminated. Locking Assemblies RfN 7012 are tightened
using standard screws and standard tools. Machining or fitting
work is not required.
EASY REMOVAL
Release the locking screws, and the Locking Assembly RfN
7012 can be removed. The steep angle of the double tapers
(approx. 28∞) prevents selflocking and ensures that the
Locking Assembly can be released without difficulty.
4
RINGFEDER® Locking Assemblies RfN 7012
LOW SUSCEPTIBILITY TO CONTAMINATION
When the locking screws are tightened down, the contact
(functional) surfaces are pressed firmly together, so preventing
the ingress of dirt and moisture.
UNLIMITED APPLICATION RANGE
Locking Assemblies RfN 7012 are most suitable for securing all
types of bosses and hubs on shafts and axles. They efficiently
replace shrink fits, key and polygon connections, splined shafts,
etc. These Locking Assemblies are used for the connection of
gearwheels, chain sprockets, levers, cams, cam plates, belt
pulleys, brake drums, flywheels, couplings and clutches, shaftmounted gearings, flanges, rope sheaves, track wheels,
impellers, ship and aircraft propellers, etc. and are giving every
satisfaction in these and countless other applications.
EASY ADJUSTABILITY
Locking Assemblies RfN 7012 need no stops. Bosses and hubs
can therefore be located and locked at any point of the shaft.
PERFECT TRUE RUNNING
Forming a frictional lock connention, Locking Assemblies RfN
7012 have absolutely no play.
FREEDOM FROM WEAR
Having no moving parts, Locking Assemblies RfN 7012 can be
tightened and released as often as required. The locking screws
are standard items and thus readily available.
HIGH FATIGUE STRENGTH UNDER ALTERNATING TORSIONAL STRESSES
Neither shaft nor hub have keyways. Thus, notch effect is
minimized and a high polar section modulus is at the disposal
of the designer.
OVERLOAD PROTECTION EFFECT
When the permissible load is exceeded, Locking Assemblies
RfN 7012 will slip. In this way, they can safeguard valuable
machine components against damage. However, the Locking
Assembly connection is subject to the same laws as all other
frictional lock connections, and is not suitable for use as
slipping clutches.
EASY CALCULATIONS
This catalogue lists all interesting data in the form of quickreference tables.
5
RINGFEDER® Locking Assemblies RfN 7012
Locking Assembly designation for shaft diameter = 70 mm: Locking Assembly RINGFEDER® 70 x 110 RfN 7012
Surface pressures
between Locking
Transmissible
Assembly and
torques
axial
hub
forces shaft
Locking Assembly dimensions
Ident-No.
6 996 124
990 930
990 957
990 985
990 937
990 981
990 981
7 990 332
991 007
5 996 236
991 015
7 990 359
991 023
7 990 367
991 031
991 040
991 058
991 066
991 074
991 082
991 090
991 104
991 112
991 120
991 139
991 147
991 155
991 163
991 171
991 180
991 198
991 201
991 210
991 228
991 236
991 244
991 252
991 260
991 279
991 287
991 295
991 309
991 317
991 325
991 333
991 341
991 350
991 368
991 376
991 384
991 392
991 406
991 414
991 422
991 430
991 449
991 457
991 465
991 473
991 481
991 490
991 511
991 520
dxD
mm
19
20
22
24
25
28
30
32
35
38
40
42
45
48
50
55
60
65
70
75
80
85
90
95
100
110
120
130
140
150
160
170
180
190
200
220
240
260
280
300
320
340
360
380
400
420
440
460
480
500
520
540
560
580
600
620
640
660
680
700
720
740
760
780
800
820
840
860
880
900
920
940
960
980
1000
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
47
47
47
50
50
55
55
60
60
65
65
75
75
80
80
85
90
95
110
115
120
125
130
135
145
155
165
180
190
200
210
225
235
250
260
285
305
325
355
375
405
425
455
475
495
515
545
565
585
605
630
650
670
690
710
730
750
770
790
810
830
850
870
890
910
930
950
970
990
1010
1030
1050
1070
1090
1110
L
20
20
20
20
20
20
20
20
20
20
20
24
24
24
24
24
24
24
28
28
28
28
28
28
33
33
33
38
38
38
38
44
44
52
52
56
56
56
66
66
78
78
90
90
90
90
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
102
I
mm
L1
17 27,5
17 27,5
17 27,5
17 27,5
17 27,5
17 27,5
17 27,5
17 27,5
17 27,5
17 27,5
17 27,5
20 33,5
20 33,5
20 33,5
20 33,5
20 33,5
20 33,5
20 33,5
24 39,5
24 39,5
24 39,5
24 39,5
24 39,5
24 39,5
26
47
26
47
26
47
34
52
34
52
34
52
34
52
38
60
38
60
46
68
46
68
50
74
50
74
50
74
60 86,5
60 86,5
72 100,5
72 100,5
84
116
84
116
84
116
84
116
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
96
130
T or
Nm
255
270
300
360
380
470
500
630
700
870
920
1500
1610
1700
1770
2270
2470
3040
4600
4900
5200
6300
6600
7900
9600
10500
13100
17600
20900
24200
28000
32800
37800
46500
52500
68000
85500
104000
128000
153000
210000
224000
294000
308000
322000
374000
455000
470000
515000
560000
600000
630000
680000
735000
775000
825000
865000
925000
965000
1030000
1070000
1140000
1210000
1250000
1300000
1370000
1450000
1520000
1590000
1650000
1710000
1790000
1870000
1940000
2000000
Fax
kN
p
27
27
27
30
30
33
33
40
40
46
46
72
72
71
71
83
83
93
132
131
131
148
147
167
192
191
218
272
298
324
350
386
420
490
525
620
715
800
915
1020
1310
1310
1630
1620
1610
1780
2060
2040
2160
2240
2320
2340
2440
2540
2580
2660
2700
2800
2840
2960
2980
3080
3180
3220
3260
3340
3460
3540
3620
3680
3720
3820
3900
3960
4000
220
210
195
195
190
185
175
192
180
188
180
226
210
196
190
200
180
190
210
195
180
195
180
195
195
180
185
165
165
170
170
160
165
150
150
150
160
165
145
150
150
145
145
135
130
135
130
125
125
125
125
120
120
120
120
120
115
120
115
115
115
115
115
115
115
115
115
115
115
115
110
110
115
110
110
Bold printed types are standard
6
Locking screws
DIN EN ISO 4762
(DIN 912) – 12.9
Thread
p´
Qty.
90
90
90
95
95
95
95
105
105
110
110
125
125
115
115
130
120
130
130
125
120
130
125
135
135
125
135
115
125
125
130
120
125
115
115
115
125
130
115
120
120
115
115
110
105
110
105
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
8
8
8
9
9
9
9
12
12
15
15
12
12
12
12
14
14
16
14
14
14
16
16
18
14
14
16
20
22
24
26
22
24
28
30
26
30
34
32
36
36
36
36
36
36
40
40
40
42
44
45
45
48
50
50
52
54
56
56
60
60
62
64
65
66
68
70
72
74
75
76
78
80
81
82
dG
TA
Nm
N/mm2
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
6
6
6
6
6
6
6
6
6
6
6
8
8
8
8
8
8
8
10
10
10
10
10
10
12
12
12
12
12
12
12
14
14
14
14
16
16
16
18
18
20
20
22
22
22
22
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Hilfs- Weigh
gewinde
t
18
18
18
18
18
18
18
18
18
18
18
22
22
22
22
22
22
22
25
25
25
25
25
25
30
30
30
35
35
35
35
40
40
45
45
50
50
50
60
60
70
70
80
80
80
80
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
14
14
14
14
14
14
14
14
14
14
14
35
35
35
35
35
35
35
70
70
70
70
70
70
125
125
125
125
125
125
125
190
190
190
190
295
295
295
405
405
580
580
780
780
780
780
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
dD
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
8
8
8
8
8
8
8
8
8
8
8
10
10
10
10
10
10
10
12
12
12
12
12
12
14
14
14
14
14
14
14
16
16
16
16
20
20
20
22
22
24
24
27
27
27
27
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
≈
kg
0,24
0,24
0,23
0,26
0,25
0,3
0,29
0,34
0,32
0,36
0,34
0,6
0,57
0,62
0,6
0,63
0,69
0,73
1,26
1,33
1,4
1,49
1,53
1,62
2,01
2,15
2,35
3,51
3,85
4,07
4,3
5,78
6,05
8,25
8,65
11,22
12,2
13,2
19,2
20,5
29,6
31,1
42,2
44
46
50
64,6
67,4
71
72,6
80
82
85
88
91
93
96
99
102
104
107
110
113
116
118
121
124
127
129
132
135
138
140
143
146
Explanations to the opposite table
Locking Assemblies RINGFEDER® RfN 7012 are not selfcentering. Consequently, the true running of hubs mounted with
these Locking Assemblies is governed by the efficiency of the
shaft centering action is governed by the play between the
remaining boss or hub bore and the shaft, as well as by the
mating length between hub and shaft
Fitting Locking Assemblies:
The values for T, Fax, p and p´ apply to Locking Assemblies that
are lightly oiled prior to being fitted (µ = 0,12).
Fig. 2 · Locking Assembly RINGFEDER® RfN 7012
For more details see page 12.
d x D, L, l, L1 = Basic dimensions, Locking Assembly not
tightened
T
Surfaces finishes:
For shafts and hub bores:
Ra 3,2 µm
Corresponds to RMS < 125 micro-inches.
= Transmissible torque
Fax = Transmissible axial force
p
Tolerances:
= Approx. Surface pressure between Locking Assembly
and shaft
Locking Assemblies RfN 7012 can bridge large deviations from
nominal sizes without any torque losses.
p´ = Approx. Surface pressure between Locking Assembly
and hub
We do not stipulate any particular clearances. The following
may be taken as guide values:
TA = Required tightening torque per locking screw (tighten
with torque wrench)
Shaft: all fits between k11 and h 11.
Hub: all fits between N 11 and H 11.
dD = Auxiliary thread in the front thrust ring. The screws at
these points are special marked for easy indentification.
The Locking Assembly should be located as symmetrically as
possible between shaft and hub bore in order to avoid excessive deformations of the relatively thickwalled thrust rings. If the
shaft is smaller than nominal d, the bore should exceed nominal D to the same extent and vice versa. The difference between
both deviations of the nominal dimensions should not exceed
IT 9 (with regard to d).
Typical application:
Location of several Locking Assemblies RfN 7012:
If several Locking Assemblies are to be installed the transmission values of the opposite table can be added in case the
Locking Assemblies are located within a distance of 4 L1.
Change of screw tightening torques:
The Locking Assemblies are generally equipped with screws of
the quality 12.9. If required, the transmission values can be increased by increasing the tightening torques of the screws (for
quality 12.9 see page 10). A reduction of the surface pressures
and the transmission values by diminished tightening of the
screws also is possible. The admissible lower limit results from
the multiplication of theTA-values of the opposite table by 0,6.
There is an approximate linear relationship between TA, T,
Fax, p and p´ (Hub and hollow shaft calculation according to
the equations on page 11)!
Fig. 3 · Hub mounted with Locking Assembly RfN 7012
DN = Diameter of the hub above the Locking Assembly, see pages 8, 9 and 10 (radial load).
b L1; L1 table on page 6
7
RINGFEDER® Locking Assemblies RfN 7012
Required hub outside diameter DN when using one Locking Assembly RfN 7012 depending on the yield point of the hub material
The values in the table for DN apply to:
The use of one Locking Assembly RfN 7012
Width of the hub
Depth of the bore
B2l
b L1
Hub section unweakened
(see hub calculation page 11)
Cast hubs should be of perfect quality (flawless).
Locking Assembly
RfN 7012
tightening
torqueper
dimension
screw
dxD
mm
19
20
22
24
25
28
30
32
35
38
40
42
45
48
50
55
60
65
70
75
80
85
90
95
100
110
120
130
140
150
160
170
180
190
200
220
240
260
280
300
320
340
360
380
400
420
440
460
480
500
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
47
47
47
50
50
55
55
60
60
65
65
75
75
80
80
85
90
95
110
115
120
125
130
135
145
155
165
180
190
200
210
225
235
250
260
285
305
325
355
375
405
425
455
475
495
515
545
565
585
605
Required min. hub outside diameter DN (mm) for:
yield point Rp0,2 ( N/mm2)
150
180
200
220
270
300
350
400
58
58
58
62
62
68
68
76
76
84
84
100
100
104
104
115
118
128
149
153
158
169
173
185
198
206
225
234
252
266
284
296
313
325
338
370
405
440
462
493
533
553
592
610
630
660
695
715
740
765
57
57
57
61
61
67
67
74
74
81
81
97
97
101
101
111
115
124
144
148
154
164
168
178
192
200
218
228
245
258
275
288
303
316
329
360
394
425
450
480
517
537
575
594
615
650
675
695
715
740
55
55
55
59
59
65
65
72
72
79
79
93
93
98
98
107
111
120
138
143
148
158
162
172
184
193
209
220
237
249
265
278
292
305
317
348
380
410
433
462
500
519
556
576
595
625
655
675
695
720
54
54
54
58
58
64
64
71
71
77
77
91
91
95
95
104
108
116
134
139
144
153
157
166
178
187
203
214
230
242
257
270
284
298
310
339
369
396
423
450
486
506
542
562
585
608
640
660
680
705
DN
mm
TA
Nm
14
14
14
14
14
14
14
14
14
14
14
35
35
35
35
35
35
35
70
70
70
70
70
70
125
125
125
125
125
125
125
190
190
190
190
295
295
295
405
405
580
580
780
780
780
780
1000
1000
1000
1000
250
69
69
69
75
75
82
82
96
96
105
105
130
130
132
132
151
152
169
196
200
203
223
226
247
265
269
302
297
330
347
374
380
408
413
430
470
530
578
585
642
693
700
748
762
790
828
853
865
895
925
65
65
65
70
70
77
77
87
87
96
96
117
117
120
120
136
138
152
176
180
184
199
203
219
236
242
268
270
296
312
335
344
366
375
390
428
475
518
533
572
618
636
680
700
715
758
786
800
825
855
62
62
62
67
67
74
74
84
84
92
92
111
111
114
114
128
131
143
166
171
175
189
193
208
223
230
254
257
282
297
317
328
349
357
372
408
453
490
507
545
590
610
653
670
690
726
755
770
800
825
61
61
61
66
66
72
72
81
81
89
89
107
107
111
111
123
126
138
160
165
169
181
186
199
214
222
243
250
272
286
304
316
336
346
360
395
436
472
492
526
568
588
630
646
665
705
732
750
775
805
8
59
59
59
63
63
69
69
78
78
85
85
103
103
106
106
118
121
132
152
157
161
173
178
189
203
212
231
240
260
273
291
302
321
333
346
379
416
450
472
505
545
564
605
623
640
675
705
725
750
775
RINGFEDER® Locking Assemblies RfN 7012
Required hub outside diameter DN when using two or more Locking Assemblies RfN 7012 depending on the yield point of the
hub material
The values in the table for DN apply to:
The use of two or more Locking Assembly RfN 7012
Width
of the hub
B L1 · (1+ n)
n = number of Locking Assemblies used
Hub section unweakened
(see hub calculation page 11)
Cast hubs should be of perfect quality (flawless).
Locking Assembly
RfN 7012
tightening
torqueper
dimension
screw
dxD
mm
19
20
22
24
25
28
30
32
35
38
40
42
45
48
50
55
60
65
70
75
80
85
90
95
100
110
120
130
140
150
160
170
180
190
200
220
240
260
280
300
320
340
360
380
400
420
440
460
480
500
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
47
47
47
50
50
55
55
60
60
65
65
75
75
80
80
85
90
95
110
115
120
125
130
135
145
155
165
180
190
200
210
225
235
250
260
285
305
325
355
375
405
425
455
475
495
515
545
565
585
605
Required min. hub outside diameter DN (mm) for:
yield point Rp0,2 ( N/mm2)
150
180
200
220
270
300
350
400
62
62
62
67
67
73
73
83
83
91
91
111
111
114
114
128
131
143
165
170
174
188
192
206
221
229
252
257
280
295
315
326
347
357
371
406
450
488
506
544
587
606
649
666
683
722
752
767
794
821
60
60
60
65
65
71
71
80
80
88
88
106
106
110
110
122
125
136
158
163
167
179
184
197
211
219
241
247
269
283
301
313
332
343
357
391
431
467
487
522
564
583
625
643
660
697
727
743
769
795
58
58
58
62
62
69
69
77
77
84
84
101
101
105
105
115
119
129
149
154
159
170
174
186
199
208
227
236
255
268
285
298
315
327
340
373
409
442
465
497
537
556
596
614
632
666
696
713
738
763
56
56
56
61
61
67
67
74
74
81
81
97
97
101
101
111
115
124
144
148
153
163
168
178
191
200
218
227
245
258
274
287
303
316
329
360
394
424
449
479
517
537
575
594
613
644
674
692
716
741
DN
mm
TA
Nm
17
14
14
14
14
14
14
14
14
14
14
35
35
35
35
35
35
35
70
70
70
70
70
70
125
125
125
125
125
125
125
190
190
190
190
295
295
295
405
405
580
580
780
780
780
780
1000
1000
1000
1000
250
79
79
79
87
87
96
96
113
113
127
127
168
168
163
163
200
192
223
258
257
256
294
291
335
359
347
409
368
425
447
493
480
525
511
531
582
682
764
725
800
864
868
929
931
932
1009
1026
1024
1060
1097
72
72
72
78
78
86
86
99
99
111
111
140
140
141
141
164
163
184
213
215
218
242
243
270
290
290
330
316
355
374
406
408
440
440
457
501
571
628
624
680
734
747
800
811
821
879
904
911
943
976
69
69
69
75
75
82
82
94
94
104
104
130
130
132
132
151
152
169
196
199
202
222
225
247
265
268
302
296
329
346
374
380
407
411
428
469
528
578
584
633
683
699
748
762
775
826
853
863
894
924
66
66
66
72
72
79
79
90
90
99
99
122
122
125
125
142
144
159
184
188
192
209
212
231
248
253
282
281
310
327
351
359
384
390
406
445
498
543
554
599
647
664
710
726
740
787
815
827
856
886
9
63
63
63
68
68
75
75
85
85
94
94
115
115
118
118
132
135
148
171
176
180
195
199
214
230
237
262
265
290
306
327
337
359
368
383
419
466
506
522
562
607
625
669
686
702
744
773
787
815
843
RINGFEDER® Locking Assemblies RfN 7012
Calculations
Transmissible torques
T
Resulting torques TR
Transmissible axial forces
Fax
When torque and axial force act simultaneously, one has to
check whether the resulting torque TR can be safely transmitted by the Locking Assemblies.
A connection made with a Locking Assembly RfN 7012 is
similar to a shrink fit. In both cases, transmission of peripheral
force Fax or torque T is effected by contact pressures in the
joints between inner ring and shaft and outer ring and hub. In
the case of shrink fits, the pressure is generated by contraction
or expansion (after heating the hub or chilling the shaft), and in
the case of the Locking Assembly RfN 7012 by radial deformation of the inner and outer rings following axial displacement of
two double tapers.
TR =
1)
Fax = FN · 2)
If the Locking Assemblies RfN 7012 are subject to radial forces,
the surface pressure prad generated by them (table on page 6)
must be higher than the surface pressure prad resulting from
the radial load Fr.
Formulae 3 to 5 give due consideration to the special shape of
the Locking Assembly (cf. Fig. 4). In formula 3, k is a safety
factor governed by the size of the Locking Assembly.
Fax = 2 · T
d
FN =
F
tan ( + )
=
F
0,381
g
Radial load Fr
d
T = FN · ·
2
d
·k
2
6)
2
2
g
Where:
Tg = max. torque to be transmitted
Fg = max. axial force to be transmitted
d = shaft diameter
Formulae 1 and 2 are generally applicable.
T = FN · ·
d
T + (F · )
2
prad =
Fr
d·l
7)
3)
Where d = shaft diameter and I the load-bearing width of the
Locking Assembly. The admissible pressure prad is limited. We
like to be of assistance.
The composed surface pressure(p + prad) must be borne in
mind when calculating the hub and the hollow shaft (page 11)
4)
Screws, technical data
The formulae given above clearly show that the obtainable
frictional connection is directly proportional to the sum of screw
pre-tension forces Fv. For this reason, the locking screws must
always be tightened down using a torque wrench.
Information about the torque wrench on page 26.
5)
tan = 0,25
tan = = 0,12
The following table contain the most important data on common
screw sizes and grades.
In the Locking Assemblies RfN 7012 the clamping force F is
obtained by screws. F corresponds to the sum of initial
clamping forces Fv.
Regular thread 1 (metric)
8.8
dG
10
Fv
TA
12.9
Fv
TA
Fv
M
M
M
4
5
6
2,9
6,0
10
3900
6350
9000
4,1
8,5
14
5450
8950
12600
4,9
10
17
6550
10700
15100
(M
M
(M
7)
8
9)
16
25
36
13200
16500
22000
23
35
51
18500
23200
30900
28
41
61
22200
27900
37100
M 10
M 12
M 14
49
86
135
26200
38300
52500
69
120
190
36900
54000
74000
83
145
230
44300
64500
88500
M 16
M 18
M 20
210
290
410
73000
88000
114000
295
405
580
102000
124000
160000
355
485
690
123000
148000
192000
M 22
M 24
M 27
550
710
1050
141000
164000
215000
780
1000
1500
199000
230000
302000
930
1200
1800
239000
276000
363000
M 30
1450
262000
2000
368000
2400
442000
1)
Fig. 4 · Forces acting on the plane Locking Assembly profile.
10.9
TA
According to Bauer & Schaurte
TA = Tightening torque (Nm)
Fv = Initial clamping force (N)
(Screws oiled, µtotal = 0,14)
RINGFEDER® Locking Assemblies RfN 7012
Hub and hollow shaft calculation
because of the differing hub and hollow shaft configurations.
Constructions in which Locking Assemblies are intended to be
arranged under or above bearings should therefore be avoided
as far as possible, or be more closely investigated (e.g. test
clamping).
Equations for thick-walled cylinders give good service in the
estimation of the tangential (tension) stresses occuring in the
hub and hollow shaft. Exact determination of the true stresses
and deformations (expanding, contraction) is very difficult in
view of the wide scatter of the coefficients of friction and
Hub calculation
Shaft calculation
1)
p´
p· d
D
1)
aW
2)
aN
=
DN
D
2)
tiW 2 · p · C3 ·
3)
tiN =
p´(aN2 + 1)
aN2 – 1
; B=l
3)
taW p · C3 ·
4)
taN =
2 · p´
aN2 – 1
; B=l
4)
dB
5)
tiN =
6)
taN =
7)
DN
d
dB
d·
2l
C3 · p´· 2
aN2 – 1
2l
; B
5)
dB
d·
DN
D·
aW2 + 1
aW2 – 1
R
Rp0,2W – 2 · p · C3
a)
R
C · p´
Rp0,2N + C3 · p´
R
C · p´
Rp0,2N + C3 · p´
R
Rp0,2W – 2 · p · C3
– dG
b)
p0,2W
dB · tiW
6)
dB a)
7)
d
b)
8)
Rp0,2W
p
c)
9)
pzul. Rp0,2W 1 –
EW
p · d · (m – 1)
+ dG
c)
EW · m
p0,2N – 3
8)
aW2
aW2 – 1
p0,2W
C3 · p´(aN2 + 1)
; B
aN2 – 1
D·
=
c)
p0,2N – 3
9)
10)
DN p´zul. DN · taN
EN
Rp0,2N
C3
·
DN2 – D2
DN2 + D2
d dB
2
a)
C3 · 2
a)
a) cross section of the hollow shaft below the Locking Assembly, unweakened and
hollow shaft longer than 2 l (generally the case. Hollow shafts 2 l are very rare).
C3 = 0,6 for one Locking Assembly
C3 = 0,8 for two or more Locking Assemblies
a) cross section of the hub above the Locking Assembly, unweakened.
C3 = 0,6 for one Locking Assembly and B 2 l
C3 = 0,8 for two or more Locking Assemblies and
B L1 · (1 + n); n = number of Locking Assemblies
C3 = 1 for one or more Locking Assemblies and
B = l bzw. B = L1 · n
b) if bores or threads (dG) in the hollow shaft.
C3 = 0,8
b) if bores or threads(dG) in the hub.
C3 = 0,8 if B 2 l or B L1 · (1 + n)
C3 = 1 if B = l or B = L1 · n
c) for solid shafts
for steel:
E
= 210000 N/mm2
m = 10/3
c) approximated value. A higher scatter range is possible, as the value depends
on the actual coefficient of friction and the shape of the hub.
Fig. 5 Sketch for hub and hollow shaft calculation
11
RINGFEDER® Locking Assemblies RfN 7012
Installation and removal instructions*
Installation
Removal
Since the force is transmitted by contact pressure and friction
between functional surfaces, condition of contact surfaces and
proper tightening of the locking screws are of great importance
(see point 1).
Locking Assemblies RINGFEDER® RfN 7012 are not selflocking. The taper of the individual rings is such that the inner
and outer rings spring apart. On the last screw being loosened.
The washers under the special marked screws protect the
auxiliary (removal) threads against damage; these washers
must be replaced after having been used several times.
1. All contact surfaces, including screw threads and screw head
bearing surfaces, must be clean and slightly oiled. In this
condition, the shaft, hub and Locking Assemblies are to be
assembled. (Do not use Molybdenum Disulphide!)
If relatively high forces are needed to to extract a Locking
Assembly that has already been loosened (e.g. if the Locking
Assembly has to be pushed against the weight of a heavy boss
or hub), any type of removal device may be used, but the screws
must only be slackened and not screwed out too far. As long as
this instruction is followed, there is no objection against the use
of a removal device, provided the forces applied are kept low.
2. Tighten locking screws lightly and align hub.
3. Tighten screws evenly in diametrically opposite sequence and
do this in two or three stages up to the indicated tightening
torque TA.
4. Re-check tightening torque by applying it to all screws all the
way around. When no screw will turn any more, the assembly
is completed.
The auxiliary threads have only abour 3-5 effective courses
and are not cut right through.
Do not use these holes for jack screws.
Information about the torque wrench on page 26.
Dirty or used Locking Assemblies must be disassembled and
cleaned before fitting. For reassembly the sequence as per fig.
6 is recommended.
The special marked screws are fitted with washers in order to
protect the auxiliary threads in the front thrust ring. In all other
respects they have the same function as the other screws and
serve only to identify the position of the auxiliary threads.
Fig. 7 If the rear thrust ring is not automatically released, the screws have to be
turned out by a few threads. Light tapping against the screw heads causes the rear
thrust ring to spring backwards.
1
2
3
4
5
6
rear thrust ring
outer ring
inner ring
front thrust ring
washer
locking screw
Fig. 8 Should the front thrust ring jam, it is released in a similar way. The special
marked screws are removed to expose the auxiliary threads of the front thrust ring.
The front thrust ring can be released and a Locking Assembly which is located
deeply in the hub bore can be removed by corresponding screws.
Fig. 6 ·Locking Assembly RINGFEDER® RfN 7012. Designation of components.
12
RINGFEDER® Locking Assemblies RfN 7012
Constructions hints
Fig. 9 · Locking Assembly RINGFEDER®. Connection. Design, designations
Fig. 10 · Locking Assembly RINGFEDER® RfN 7012
Fig. 11 · Track wheel mounted using one Locking Assembly RfN 7012.
The Locking Assembly must transmit above all the torque. The minor bore of the
hub should be as long as possible and have close clearances in order to improve
true running and to absorb stresses resulting from the axial force acting off-centre
on the rim.
Fig. 12 · Coupling half mounted with one Locking Assembly RfN 7012.
In this arrangement, the shaft is stepped to permit the largest possible hub crosssection.
13
RINGFEDER® Locking Assemblies RfN 7012
Constructions hints
Fig. 13 · Connection of two shafts using one Locking Assembly RfN 7012 per
shaft. The hub bore need not be stepped; if a through-bore hub is used, it is
recommended that a centering ring be fitted to improve trueness of running.
Fig. 14 · Lever mounted using one Locking Assembly RfN 7012.
Frictional-connection Locking Assembly permits stepless movement of the lever
to any degree of accuracy required.
Fig. 15 · Flywheel mounted using one Locking Assembly RfN 7012.
Fig. 16 · Bevel gear mounted using one Locking Assembly RfN 7012.
In this case the Locking Assembly transmits both the torque and the tooth
pressure axial component.
14
RINGFEDER® Locking Assemblies RfN 7012
Constructions hints
Fig. 17 · Shaft-mounted gearing secured using 3 Locking Assemblies RfN 7012.
Belt drum mounted using 2 Locking Assemblies RfN 7012.
1/2000
to 1/3000 as related to the bearing spacing (recommended empirical value as
quoted by the relevant industry). The drum-shaft connection on the drive side
must be calculated for the full torque to be transmitted.
Fig. 18 · Belt drum mounted with Locking Assemblies RfN 7012.
With this and similar constructions, it must be ensured that the shaft deflections
are kept within permissible limits. For practical purposes, the shaft deflection of
15
RINGFEDER® Locking Assemblies RfN 7012
Constructions examples
Fig. 19 · Cable drum of a 400 kN foundry crane.
The drum is mountedusing Locking Assemblies RfN 7012
Messrs. Koninklijke Nederlandsche Grofsmederij, Leiden, Netherlands,
works photograph
Fig. 20 · Ossberger turbine
The rotor is mounted using 2 Locking Assemblies RfN 7012.
Messrs. Ossberger Turbinenfabrik, Weissenburg, works photograph
Fig. 21 · Precision stamping press.
Gearwheels mounted using Locking Assemblies RfN 7012.
Messrs. Osterwalder AG, Lyss/Switzerland, works photograph
Fig. 22 · Primary crusher, Type 2 -1001.
Vee-belt pulley and disc-type flywheel mounted with Locking Assemblies RfN 7012.
Messrs. A. M¸ller, Rottweil, works photograph
16
RINGFEDER® Locking Assemblies RfN 7012
Constructions examples
Fig. 23 · ANKER (R) Screw-type automatic injection moulding machine.
Locking Assemblies RfN 7012 are used for securing the cranks actuating
the clamping plate.
Messrs. Ankerwerk Gebr. Goller, N¸rnberg, works photograph
Fig. 24 · Details of the injection moulding machine shown in Fig. 23, with the
cranks, Locking Assemblies RfN 7012, and plate.
Messrs. Ankerwerk Gebr. Goller, N¸rnberg, works photograph
Fig. 25 · Crank press.
Gearwheel mounted with Locking Assemblies RfN 7012.
Messrs. Hatebur, works photograph
Fig. 26 · Bucket wheel excavator.
Locking Assemblies RfN 7012 used in bucket wheel, the bucket wheel drive,
travelling gear drive, the belt drums, etc.
Messrs. Krupp, works photograph
17
RINGFEDER® Locking Assemblies RfN 7012
Constructions examples
Fig. 27 · Bucket-wheel excavator.
Locking Assemblies RfN 7012 used in the bucket-wheel, slewing and travelling
drives.
Messrs. DEMAG-Lauchhammer, works photograph
Fig. 28 · Shaft couplings.
Fitted with Locking Assemblies RfN 7012.
Messrs. B. Willy Lein, Hilden, works photograph
Fig. 29 · Automatic thread rolling machine.
Cam disc mounted using one Locking Assembly RfN 7012.
Messrs. Reed Rolled Thread Die Co., Holden/USA, works photograph
Fig. 30 · Single-column eccentric press.
Gearwheels mounted on the crankshaft with Locking Assemblies RfN 7012.
Messrs. A. Richter, Kassel-Lohfelden, works photograph
18
RINGFEDER® Locking Assemblies RfN 7012
Constructions hints
Fig. 31 · Ship propeller.
Mounted with 2 Locking Assemblies RfN 7012.
Fig. 32 · Ship propeller being fitted-fig. 31.
Deutsche Werft, works photograph
Fig. 33 · Cam actuator.
For the Ossberger turbine, cams mounted using Locking Assemblies RfN 7012.
Messrs. Ossberger Turbinenfabrik, Weissenburg, works photograph
Fig. 34 · Lever mountings.
These levers are used in a hydraulic welding press; they are mounted using
Locking Assemblies RfN 7012.
Messrs. Keller & Knappich GmbH, Augsburg, works photograph
19
RINGFEDER® Locking Assemblies RfN 7012
Constructions examples
Fig. 35 · Bogiflex Drive TSP.
Locking Assemblies RfN 7012 in the pinion support.
Messrs. Tool Steel Gear & Pinion Co., Cincinnati/USA
Fig. 36 · Conveying belt drums.
Mounted on the drum shaft using Locking Assemblies RfN 7012.
Messrs. Italsider Co./Italy
Fig. 37 · Textile machine.
A Locking Assembly 55 x 85 RfN 7012 is used for mounting the cam.
Messrs. Tsudakoma Industrial Co., Ltd., Kanazawa/Japan
SACAM, Mulhouse / France
Fig. 38 · Medical betatron ray machine for cancer treatment.
Positioning for radial guide with Locking Assemblies 70 x 110 RfN 7012.
Messrs. Shimazu Seisakusho, Kyoto/Japan
20
RINGFEDER® Locking Assemblies RfN 7012
Constructions examples
Fig. 39 · DEMAG standard-gauge Diesel-driven crane.
Bevel gears mounted with Locking Assemblies RfN 7012.
Waggonfabrik Uerdingen AG, works photograph
Fig. 40 · Ore transporter.
Locking Assemblies RfN 7012 used in belt drums and shaft mounted gearings.
Pohlig-Heckel-Bleichert AG, Rohrbach, works photograph
Fig. 41 · Saw frame.
Connecting rod mounted with Locking Assembly RfN 7012.
Esterer AG, Altˆtting, works photograph
Fig. 42 · Pipe cutting mill.
Locking Assemblies RfN 7012 used in vee-belt pulleys.
Messrs. Pallman, Zweibrücken
21
RINGFEDER® Locking Assemblies RfN 7012
Constructions examples
Fig. 43 · Winder machine.
Lever mounted with Locking Assemblies 300 x 375 RfN 7012.
Messrs. Nishimura Co. Ltd., Japan
Fig. 44 · Bolt forming machine.
Pinion mounted with Locking Assembly 120 x 165 RfN 7012.
Messrs. Sakamura Machine Mfg. Co. Ltd., Japan
Fig. 45 · Bolt forming machine.
Locking Assemblies RfN 7012 used in levers, can discs and vee-belt pulleys.
Messrs. Sakamura Machine Mfg. Co. Ltd. Japan
Fig. 46 · Chain conveyor.
Sprockets mounted with Locking Assemblies 70 x 110 RfN 7012.
Messrs. Hitachi Zosen Co. Ltd., Japan
22
The ABC of Locking Assemblies RINGFEDER® RfN 7012
Adjustability
Fatigue strength under alternating torsion stresses
The friction-lock connection by means of Locking Assemblies
RfN 7012 is infinitely variable and can be adjusted with a high
degree of accuracy.
The greatest variable stress component oscillating about the
mean stress zero a specimen can resist an unlimited number of
times without fracture or inadmissible deformation (see DIN
50100). This value is influenced by shape and surface finish.
The ratio between the fatigue strength of the unnotched and
polished specimen is referred to a notch factor .
varies from material to material and decreases in value as
the static tensile strength value increases.
Axial force Fax
The axial thrust that can be transmitted by Locking Assemblies
RfN 7012, regardless of the type of load encountered (static,
increasing, alternating or impact). Fax can be calculated by
dividing the torque by the shaft radius (Fax = 2 x T/d). In comparison with these theoretical values, substantially higher
values have been established in practical operations. (values for
Fax see table on page 6.)
When Locking Assemblies RINGFEDER® RfN 7012 are used,
both shaft and hung retain their full crosssections, i.e. are not
grooved. Consequently, the stress states at the connection point
are virtually identical with those of a smooth shaft, i.e. the material is utilized by almost 100%.
Calculations
Locking Assemblies RfN 7012:
Hubs:
Hollow shafts:
see page 10
see page 11
see page 11
Fitting
see page 12
Fretting / Galling
Centering action
Damage to or destruction of shaft, hub bore or Locking Assembly surfaces as a result of overloading followed by → Slip.
Fretting can always be avoided by correct dimensioning of the
connection.
Guiding action of the shaft in the minor bore of the hub. The
clearance between shaft and hub bore and the length of the
minor bore have the greatest effect on True running of the
mounted hub.
Fretting corrosion
Corrosion between the contact surfaces of ferrous metals. Even
the smallest relative movements favour and accelerate fretting
corrosion; lubricants can delay the process, but not stop it
altogether. Longterm prevention of fretting corrosion can be
achieved only by designing the connection in such a way that
relative movement is impossible. Locking Assemblies RfN 7012
greatly facilitate the solving of this problem.
Locking screws – securing of
Screws subjected to static loads need not be secured against
slackening (in some cases, lock washers, etc. can even be
harmful). The screws used in conjunction with Locking
Assemblies are normally subjected to static loads only; consequently, they need not be secured against loosening. Tightening
down to the specified torque value is quite adequate.
Fig. 47 · Locking Assembly RINGFEDER®
Principle sketch.
Clearances
see page 7
Coefficient of friction
Molykote
The catalogue values (table page 6) apply to = 0,12. Surfaces
of the Locking Assemblies, shaft and hub bore slightly oiled with
lubricants which do not contain → Molykote.
Trade name of a lubricant containing molybdenum disulphide
(MoS2). As MoS2 reduces the Coefficient of friction, it is used
for frictional connections between shafts and hubs in exceptional cases only. We urgently recommend that our advice be
sought if it is intended that lubricants containing MoS2 be used
in conjunction with Locking Assemblies.
Contact pressure p, p’
p = contact pressure between inner ring and shaft.
p’ = contact pressure between outer ring and hub
p and p’ – together with the → Coefficient of friction – determine the frictional connection value. In order to avoid deformation in the plastic range, the following values must obtain:
p
p´
Rp0,2W and
Rp0,2N
Deformations
see page 11
Exchangeability
see page 4
23
The ABC of Locking Assemblies RINGFEDER® RfN 7012
Continuation
Notch factor k
Safety
→ Fatigue strength under alternating torsion stresses.
The frictional connection values given in the tables are achieved
or even exceeded if designing is correct and the connection
properly made. The theoretical values are higher. Frictional
connections of all types – including shrink fits and press fits –
must be designed in such a way that the load peaks vary so
greatly from case to case that we are unable to give any
recommendations as regards specific safety factors.
Locking Assembly connections are insensitive to impact loads
(see fig. 48).
Notch impact strength figure
k
Produkt of the → Shape factor k (governed by material configuration) and the → Notch factor k (governed by material properties):
Formel..........
k - 1
k =
k - 1 values for
Approximate
k
0,4...0,8 – light metals and c-steels
0,6...1
– heat-treatable steels.
Overload protection
see page 5
Play, freedom from
Connections with Locking Assemblies RfN 7012 are absolutely
free of play. Like other frictional connections there is no danger
of lateral oscillation.
Fig. 48
Polar section modulus Wp
Shape factor k
In the case of circular cross sections, Wp is defined thus:
Wp = d3 /16
Proportionally factor covering stress conditions at bores, crosssection transitions, clamping points, grooves, etc. The following
applies:
The value of Wp is significantly reduced by keyways, grooves
for Woodruff and feather keys, etc. When using Locking
Assemblies RfN 7012, the full cross-section of the shaft is
available (see Shape factor k).
max
Höchstspannung
Formel......
k =
=
n
Nennspannung
(use smallest cross-sections and/or resistance moments when
determining n).
For smooth shafts k = 1
Radial load, admissible
Locking Assemblies RINGFEDER® RfN 7012 can also absorb
radial loads. It must be considered, however, that the surface
pressure resulting from the radial load with respect to the
projected surface of the locking Assembly, is smaller than the
surface pressure generated by the clamping (see also calculation on page 10).
Releasability
Locking Assemblies RfN 7012 are not self-locking. The angel of
the tapered rings is such that releasability is guaranteed even
after prolonged heavy loading. Extractors are not required.
Removal
see page 12
Rust
Because of the relatively high pressures per unit of area, rusting
cannot take place between the effective surfaces of a Locking
Assembly as well as shaft and hub Because of their split inner
and outer rings the Locking Assemblies RfN 7012 cannot
hermetically seal the clamping point. In this case we advise to
use corrosion inhibitors, seals, etc. in order to protect the
Locking Assemblies (locking screws) against corrosion.
r
grooved –
t
= 0,5
r
grooved – = 0,2
t
e. g. r = 2,5 mm
k = 2,1
W’p = 6 cm3
e. g. r = 1 mm
k = 3,4
W’p = 3,7 cm3
r
grooved – = 0,1
t
e. g. r = 0,5 mm
k = 5,4
W’p = 2,32 cm3
Fig. · 49 · Influence of the groove shape on shape factor k and thus on the
→Polar moment of resistance; extract from the work of Prof. Thum. 40 mm
(Wp = 12,56 cm3).
For smooth shafts k = 1.
24
Spannsätze RINGFEDER® RfN 7012
Slip
All shrink fits slip on overloading taking place.
→ Fretting of the contact (slipping) surfaces normally
unavoidable. Locking Assemblies subjected to high pressures
per unit of area and rotating at high peripheral speeds can be
completely destroyed. Under normal circumstances, the degree
and type of destruction do not indicate the cause of slipping.
Slipping clutch
Fig. 52 · Due to the relatively close fit between shaft and hub, the heat is dissipated readily and no significant difference in temperature occurs. The contact
pressure and thus the transmissible torque remain constant.
Locking Assemblies RINGFEDER® RfN 7012 are not suitable for
use as a slipping clutch. With their overload protection effect
they can only safeguard valuable machine components against
damage (see also page 5).
Tightening torque TA
Controlled torque per locking screw generated by the torque
wrench (see page 6, 7 and 10).
Surface finish
Surface condition of shaft and hub bore. When using Locking
Assemblies RfN 7012, Rt 16 µm.
(RMS 125 micro-inches).
Torque wrench
Standard tool indicating the tightening torque exerted on the
screw heads. As the friction lock of the Locking Assemblies
RINGFEDER® RfN 7012 is proportional to the srew tightening
torque, it is advised to use a torque wrench (see page 26).
Tangential stresses
Tensile stress in the hub bore or compression stress in the bore
of hollow shafts as a result of the
→ Contact pressures between outer locking ring and hub and/or
inner locking ring and hollow shaft. See page 11 for calculation.
True running
The relatively narrow Locking Assembly RINGFEDER® RfN
7012 serve mainly to transmit high torques and axial forces.
They are not self-centering. True running of the hub/boss is thus
governed by the → Centering action and the care taken during
→ Fitting.
Fig. 50 · Tangential stresses in shrink fits.
Temperature, influence of
Shrink fits – and thus Locking Assembly RfN 7012 connections,
too – give perfect service as long as the contact pressure in the
joint does not drop below a certain minimum value. Consequently, contact pressure in the joint at operating temperature
must be the subject of close attention. Please contact us for
advice.
Fig. 53 · Pre-centering by selection of correct fit between shaft and hub.
Wear
Fig. 51 · The air cushion between shaft and hub/boss has an insulating effect;
consequently, heat transmission is poor. The result is a difference in temperature between shaft and hub. If both hub and shaft have the same linear expansion
coefficients, the hub undergoes a higher degree of expansion than the shaft; the
diminishing contact pressure reduces the frictional connection value.
25
see page 5
Torque Wrenches
For controlled tightening of locking screws of Locking Assemblies RINGFEDER®, we offer suitable torque wrenches and
attachments. These tools facilitate the installation of our
Locking Assemblies RfN 7012 particularly on straight through
shafts. They can be used, of course, also for mounting of
Locking Assemblies RINGFEDER® RfN 7013, 7014, 7015 and
Locking Elements RINGFEDER® RfN 8006 and other screwed or
bolted connections.
The rigid square drives SSD and hex bit sockets exhibit compact
over-all dimensions and can be combined with commercially
available axtensions. The SSD-drives fit with all MCCM torque
handles. Square drives and hex bit sockets drives required for
any given Locking Assembly size are listed in following table.
Locking Assemblies
RfN 7012
Size
from
to
d
d
19
40
Recommended Tools
Hex bit
Sockets
Square
Drives
1/4– 5
Torque
Wrench
Handles
MCCM - 20 Nm
SSD– 1/4
42
65
1/4– 6
70
95
3/8– 8
100
160
3/8–10
170
200
1/2–12
220
300
1/2–14
MCCM - 100 Nm
SSD– 3/8
MCCM - 200 Nm
SSD– 1/2
MCCM - 600 Nm
Torque wrenches for larger Locking Assemblies are readily
available
Description and operation
When preset torque is reached, you hear a click and feel the
breakover. No disadvantages are caused by dials and indicators.
Torque setting is achieved by turning the adjustable micrometer
torque habdle. Every setting point is felt by a distinct stop.
Torque setting cannot accidentally change while wrench is in
use. By turning the lock screw located at the end of handle
counter-clockwise (“Lock”), the adjustable handle is locked. By
turning it clockwise (“Unlock”), the handle is unlocked.
Frictionless adjustment mechanism permits high torque
accuracy even after prolonged use.
Slim design and light weight for better accessibility to fasteners
and minimum operator fatigue.
Required attachments slide on easy onto the dovetailed and pin
locked torque handle. For release of attachments, the spring
loaded lock pin can be easily depressed by a pin or screw driver.
26
...and accessories
Torque Wrench Handles
MCCM
- 20 Nm
MCCM
- 100 Nm
MCCM
- 200Nm
MCCM
- 600 Nm
Calibration in
Nm
Nm
Nm
Nm
Torque range
4 – 20
Designation
Graduation
20 – 100 50 – 200 100 - 600
0,2
1
1
0,5
Weight
kg
0,32
0,5
0,64
3,9
A max.
mm
235
330
406
915
A min.
mm
216
303
384
903
B
mm
78
107
107
254
C
mm
51
102
118
660
F
mm
25
25
25
51
Square Drives
Designation
Square
Drive size
A
B
C
D
SSD – 4
4"
44
14
19
19
SSD – s
s"
46
20
22
25
SSD – 2
2"
48
22
25
28
mm
Hex bit Sockets
Designation
27
Square
Drive size
S
L
mm
D
4 –5
4"
5
55
11
4 –6
4"
6
55
11
s –8
s"
8
52
18
s – 10
s"
10
52
18
2 – 12
2"
12
60
24
2 – 14
2"
14
60
24
Material standards – selection
Hints for material specifications and according values of yield strength
replaced by
DIN
DIN EN
designation
aproximate range
of yield point*
N/mm2
1629
seamless tubes
for
special requirements
215
up to
355
1681
cast steel
for
common use
200
up to
300
Beibl. 1
1691
cast iron
1692
malleable cast iron
200
up to
530
1693
spheroidal graphite cast iron
250
up to
500
1705
copper - tin
and
copper - tin - zinc - alloys
90
up to
180
98 up to 228
(0,1 – limit of elongation)
1725
575
aluminium alloys
70
up to
380
17100
10025
structural and constructural steels
175
up to
365
17200
10083
heat-treatable steel
300
up to
560
17245
ferritic creep resistant cast steel
125
up to
540
17440
stainless steels
185
up to
600
* dependent on quality, kind of product and intended use
28
ISO-tolerances for shafts and bores
Allowances in µm (1 µm = 39.37 µin)
Nominal
diameter
of shaft
(mm)
d 11
e8
e7
f8
f7
g6
h 11
h9
h8
h7
above
to
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
3
6
10
6
10
18
– 30
– 40
– 50
– 105
– 130
– 160
– 20
– 25
– 32
– 38
– 47
– 59
– 20
– 25
– 32
– 32
– 40
– 50
– 10
– 13
– 16
– 28
– 35
– 43
– 10
– 13
– 16
– 22
– 28
– 34
–
–
–
4
5
6
– 12
– 14
– 17
0
0
0
– 75
– 90
– 110
0
0
0
– 30
– 36
– 43
0
0
0
– 18
– 22
– 27
0
0
0
– 12
– 15
– 18
18
30
50
30
50
80
– 65
– 80
– 100
– 195
– 240
– 290
– 40
– 50
– 60
– 73
– 89
– 106
– 40
– 50
– 60
– 61
– 75
– 90
– 20
– 25
– 30
– 53
– 64
– 76
– 20
– 25
– 30
– 41
– 50
– 60
– 7
– 9
– 10
– 20
– 25
– 29
0
0
0
– 130
– 160
– 190
0
0
0
– 52
– 62
– 74
0
0
0
– 33
– 39
– 46
0
0
0
– 21
– 25
– 30
80
120
180
120
180
250
– 120
– 145
– 170
– 340
– 395
– 460
– 72
– 85
– 100
– 126
– 148
– 172
– 72
– 85
– 100
– 107
– 125
– 146
– 36
– 43
– 50
– 90
– 106
– 122
– 36
– 43
– 50
– 71
– 83
– 96
– 12
– 14
– 15
– 34
– 39
– 44
0
0
0
– 220
– 250
– 290
0
0
0
– 87
– 100
– 115
0
0
0
– 54
– 63
– 72
0
0
0
– 35
– 40
– 46
250
315
400
315
400
500
– 190
– 210
– 230
– 510
– 570
– 630
– 110
– 125
– 135
– 191
– 214
– 232
– 110
– 125
– 135
– 162
– 182
– 198
– 56
– 62
– 68
– 137
– 151
– 165
– 56
– 62
– 68
– 108
– 119
– 131
– 17
– 18
– 20
– 49
– 54
– 60
0
0
0
– 320
– 360
– 400
0
0
0
– 130
– 140
– 155
0
0
0
– 81
– 89
– 97
0
0
0
– 52
– 57
– 63
Nominal
diameter
of shaft
(mm)
above
to
h6
h5
j6
k6
k5
m6
m5
n6
p6
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
3
6
10
6
10
18
0
0
0
– 8
– 9
– 11
0
0
0
– 5
– 6
– 8
+ 7
+ 7
+ 8
– 1
– 2
– 3
–
+ 10
+ 12
–
+ 1
+ 1
–
+ 7
+ 9
–
+ 1
+ 1
+ 12
+ 15
+ 18
+
+
+
4
6
7
+ 9
+ 12
+ 15
+ 4
+ 6
+ 7
+ 16
+ 19
+ 23
+ 8
+ 10
+ 12
+ 20
+ 24
+ 29
+ 12
+ 15
+ 18
18
30
50
30
50
80
0
0
0
– 13
– 16
– 19
0
0
0
– 9
– 11
– 13
+ 9
+ 11
+ 12
– 4
– 5
– 7
+ 15
+ 18
+ 21
+ 2
+ 2
+ 2
+ 11
+ 13
+ 15
+ 2
+ 2
+ 2
+ 21
+ 25
+ 30
+ 8
+ 9
+ 11
+ 17
+ 20
+ 24
+ 8
+ 9
+ 11
+ 28
+ 33
+ 39
+ 15
+ 17
+ 20
+ 35
+ 42
+ 51
+ 22
+ 26
+ 32
80
120
180
120
180
250
0
0
0
– 22
– 25
– 29
0
0
0
– 15
– 18
– 20
+ 13
+ 14
+ 16
– 9
– 11
– 13
+ 25
+ 28
+ 33
+ 3
+ 3
+ 4
+ 18
+ 21
+ 24
+ 3
+ 3
+ 4
+ 35
+ 40
+ 46
+ 13
+ 15
+ 17
+ 28
+ 33
+ 37
+ 13
+ 15
+ 17
+ 45
+ 52
+ 60
+ 23
+ 27
+ 31
+ 59
+ 68
+ 79
+ 37
+ 43
+ 50
250
315
400
315
400
500
0
0
0
– 32
– 36
– 40
0
0
0
– 23
– 25
– 27
+ 16
+ 18
+ 20
– 16
– 18
– 20
+ 36
+ 40
+ 45
+ 4
+ 4
+ 5
+ 27
+ 29
+ 32
+ 4
+ 4
+ 5
+ 52
+ 57
+ 63
+ 20
+ 21
+ 23
+ 43
+ 46
+ 50
+ 20
+ 21
+ 23
+ 66
+ 73
+ 80
+ 34
+ 37
+ 40
+ 88
+ 98
+ 108
+ 56
+ 62
+ 68
Nominal
diameter
of bore
(mm)
D 11
E8
E7
F8
F7
G7
H 11
H9
H8
H7
above
to
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
3
6
10
6
10
18
+ 105
+ 130
+ 160
+ 30
+ 40
+ 50
+ 38
+ 47
+ 59
+ 20
+ 25
+ 32
+ 32
+ 40
+ 50
+ 20
+ 25
+ 32
+ 28
+ 35
+ 43
+ 10
+ 13
+ 16
+ 22
+ 28
+ 34
+ 10
+ 13
+ 16
+ 16
+ 20
+ 24
+
+
+
4
5
6
+ 75
+ 90
+ 110
0
0
0
+ 30
+ 36
+ 43
0
0
0
+ 18
+ 22
+ 27
0
0
0
+ 12
+ 15
+ 18
0
0
0
18
30
50
30
50
80
+ 195
+ 240
+ 290
+ 65
+ 80
+ 100
+ 73
+ 89
+ 106
+ 40
+ 50
+ 60
+ 61
+ 75
+ 90
+ 40
+ 50
+ 60
+ 53
+ 64
+ 76
+ 20
+ 25
+ 30
+ 41
+ 50
+ 60
+ 20
+ 25
+ 30
+ 28
+ 34
+ 40
+ 7
+ 9
+ 10
+ 130
+ 160
+ 190
0
0
0
+ 52
+ 62
+ 74
0
0
0
+ 33
+ 39
+ 46
0
0
0
+ 21
+ 25
+ 30
0
0
0
80
120
180
120
180
250
+ 340
+ 395
+ 460
+ 120
+ 145
+ 170
+ 126
+ 148
+ 172
+ 72
+ 85
+ 100
+ 107
+ 125
+ 146
+ 72
+ 85
+ 100
+ 90
+ 106
+ 122
+ 36
+ 43
+ 50
+ 71
+ 83
+ 96
+ 36
+ 43
+ 50
+ 47
+ 54
+ 61
+ 12
+ 14
+ 15
+ 220
+ 250
+ 290
0
0
0
+ 87
+ 100
+ 115
0
0
0
+ 54
+ 63
+ 72
0
0
0
+ 35
+ 40
+ 46
0
0
0
250
315
400
315
400
500
+ 510
+ 570
+ 630
+ 190
+ 210
+ 230
+ 191
+ 214
+ 232
+ 110
+ 125
+ 135
+ 162
+ 182
+ 198
+ 110
+ 125
+ 135
+ 137
+ 151
+ 165
+ 56
+ 62
+ 68
+ 108
+ 119
+ 131
+ 56
+ 62
+ 68
+ 69
+ 75
+ 83
+ 17
+ 18
+ 20
+ 320
+ 360
+ 400
0
0
0
+ 130
+ 140
+ 155
0
0
0
+ 81
+ 89
+ 97
0
0
0
+ 52
+ 57
+ 63
0
0
0
Nominal
diameter
of bore
(mm)
H6
J7
above
to
upper
lower
3
6
10
6
10
18
+ 8
+ 9
+ 11
18
30
50
30
50
80
80
120
180
250
315
400
J6
K7
K6
upper
lower
upper
lower
upper
lower
upper
0
0
0
+ 5
+ 8
+ 10
–
–
–
7
7
8
+ 4
+ 5
+ 6
– 4
– 4
– 5
–
+ 5
+ 6
–
– 10
– 12
–
+ 2
+ 2
–
–
+ 13
+ 16
+ 19
0
0
0
+ 12
+ 14
+ 18
– 9
– 11
– 12
+ 8
+ 10
+ 13
– 5
– 6
– 6
+ 6
+ 7
+ 9
– 15
– 18
– 21
120
180
250
+ 22
+ 25
+ 29
0
0
0
+ 22
+ 26
+ 30
– 13
– 14
– 16
+ 16
+ 18
+ 22
– 6
– 7
– 7
+ 10
+ 12
+ 13
315
400
500
+ 32
+ 36
+ 40
0
0
0
+ 36
+ 39
+ 43
– 16
– 18
– 20
+ 25
+ 29
+ 33
– 7
– 7
– 7
+ 16
+ 17
+ 18
M7
M6
N7
N6
lower
P7
lower
upper
lower
upper
lower
upper
lower
upper
lower
upper
lower
–
7
9
0
0
0
– 12
– 15
– 18
–
–
–
1
3
4
– 9
– 12
– 15
–
–
–
4
4
5
– 16
– 19
– 23
–
–
–
5
7
9
– 13
– 16
– 20
– 8
– 9
– 11
– 20
– 24
– 29
+ 2
+ 3
+ 4
– 11
– 13
– 15
0
0
0
– 21
– 25
– 30
–
–
–
4
4
5
– 17
– 20
– 24
–
–
–
7
8
9
– 28
– 33
– 39
– 11
– 12
– 14
– 24
– 28
– 33
– 14
– 17
– 21
– 35
– 42
– 51
– 25
– 28
– 33
+ 4
+ 4
+ 5
– 18
– 21
– 24
0
0
0
– 35
– 40
– 46
–
–
–
6
8
8
– 28
– 33
– 37
– 10
– 12
– 14
– 45
– 52
– 60
– 16
– 20
– 22
– 38
– 45
– 51
– 24
– 28
– 33
– 59
– 68
– 79
– 36
– 40
– 45
+ 5
+ 7
+ 8
– 27
– 29
– 32
0
0
0
– 52
– 57
– 63
– 9
– 10
– 10
– 41
– 46
– 50
– 14
– 16
– 17
– 66
– 73
– 80
– 25
– 26
– 27
– 57
– 62
– 67
– 36
– 41
– 45
– 88
– 98
– 108
29
Technical service
Based on your technical drawings and data we are ready
to execute installation proposals to solve your specific
problems.
Many years of experience and modern calculation
methods open extraordinary possibilities of assistance.
VDA 6.1
Type approvals by:
Fax enquiry
(410)358-3142 (800)872-9329 Maryland Metrics
For technical assistance
To: RINGFEDER VBG GMBH, department KM
From:
Messrs.: ..................................................................
..................................................................................
..................................................................................
address: ................................................................
..................................................................................
..................................................................................
contact: ...................................................................
phone: ..................................................................
department: ............................................................
fax: .........................................................................
To make it easier for our technical staff and to avoid errors or mistakes your enquiry should include the following information:
Information for technical service
Expected maximum loads:
Max. torque
Max. bending moment
Max. axiall load
Max. radial load
Tg
Mg
Fg
Fr
max.
max.
max.
max.
=
=
=
=
……………………… Nm
……………………… Nm
……………………… kN
……………………… kN
=
=
=
=
=
=
=
=
……………………… mm
……………………… mm
……………………… 1/min
……………………… mm
……………………… mm
……………………… N/mm2
……………………… N/mm2
……………………… °C
Dimensionens, materials:
shaft diameter
In case of hollow shaft, internal diameter
Speed/revolutions
Hub outside diameter
Hub width
Hub material/yield strength
Shaft material/yield strength
Temperature at the connection
dW
dB
n
DN
B
Rp0,2N
Rp0,2W
Temp.
Additional information:
.................................................................................
.................................................................................
.................................................................................
.................................................................................
Please send a drawing or sketch together with your enquiry!
RINGFEDER Products are available from MARYLAND METRICS
P.O. Box 261 Owings Mills, MD 21117 USA email: sales@mdmetric.com web: http://mdmetric.com
phones: (410)358-3130 (800)638-1830 faxes: (410)358-3142 (800)872-9329
For shaft-hub connections we supply:
RINGFEDER® Shrink Discs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . for external clamping
RfN 4071 / 4091 / 4051 / 4073 / 4171
RINGFEDER® Shaft Couplings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . for an absolutely rigid connection of shafts
and high accuracy of alignment
Special designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . on request
Torque wrenches and accessories . . . . . . . . . . . . . . . . . . . . . . . . . for correct tightening conditions
S. 119.1. 31.1.01
RINGFEDER® Locking Assemblies RfN 7012 . . . . . . . . . . . . . . . . . for highly stressed shaft-hub connections
and big machining tolerances
RINGFEDER® Locking Assemblies RfN 7012-IN . . . . . . . . . . . . . . . for shafts with inch-dimensions
RINGFEDER® Locking Assemblies RfN 7013 . . . . . . . . . . . . . . . . . for higher demands to concentricity
RINGFEDER® Locking Assemblies RfN 7013-IN . . . . . . . . . . . . . . . for shafts with inch-dimensions
RINGFEDER® Locking Assemblies RfN 7014 . . . . . . . . . . . . . . . . . for extremely stressed shaft-hub connections
RINGFEDER® Locking Assemblies RfN 7015 . . . . . . . . . . . . . . . . . self-centering, for highest transmission values
as well as for the use in belt drums
RINGFEDER® Locking Elements RfN 8006 . . . . . . . . . . . . . . . . . . . adaptable design for special requirements
RINGFEDER® Locking Assemblies RfN 7110 . . . . . . . . . . . . . . . . . compact dimensions, excellent centering ability
Locking Connections
RINGFEDER Products are available from MARYLAND METRICS
P.O. Box 261 Owings Mills, MD 21117 USA email: sales@mdmetric.com web: http://mdmetric.com
phones: (410)358-3130 (800)638-1830 faxes: (410)358-3142 (800)872-9329