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Wall Mounted Jib Crane (H-Type)

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Wall Mounted Jib Crane (H-Type)
Mechanical System Design
Department of Mechanical Engineering
Executive Summary
Jib crane is a machine that is used to lift heavy loads of greater than 1 ton. There are two main
kinds of jib cranes like Column Jib cranes and Wall mounted Jib cranes. Column jib cranes are
the cranes which utilize a vertical column that is fixed on the Earth with the help of nuts and
bolts. Wall mounted jib cranes do not contain vertical columns rather they have brackets that are
used to fix the crane beam with the wall. Jib Cranes are further divided into three different kinds
on the basis of beam used i.e. C-Type Jib cranes, H-Type Jib Cranes and T-Type Jib cranes. Our
Project is to design an “H-Type” Jib crane. Talking about H-Type jib cranes, these cranes have
an H-Type beam on which the trolley is mounted.
Some required specifications, given by the client, have been utilized to design a particular jib
crane. The designed H-Type jib crane has maximum capacity of 1850 kg, a span length of 7.25
meters, maximum height of 8 meters and slewing angle is 300 degrees. Travelling mode is
manual i.e. the movement of trolley is controlled manually whereas slewing mode is motor
controlled i.e. left right turning movement of the beam shall be controlled by motor. After
considering all parameters, it has been calculated that hoist motor should have a power of 68 kW
or higher to lift the maximum desired capacity load.
Table of Contents
Executive Summary ........................................................................................................................ 2
1.
2.
Problem Definition.................................................................................................................. 9
1.1.
Problem Scope.................................................................................................................. 9
1.2.
Technical Review ............................................................................................................. 9
1.3.
Design Requirements ..................................................................................................... 10
Design Description................................................................................................................ 10
2.1.
Overview ........................................................................................................................ 10
2.2.
Structural Components ................................................................................................... 11
2.3.
Applied forces to the supported structure ...................................................................... 11
2.3.1. Loading Calculations .................................................................................................. 12
2.4.
Moment and Shear diagrams .......................................................................................... 14
2.5.
Deflection in the Beam ................................................................................................... 15
2.6.
Trolley Design ................................................................................................................ 16
2.7.
Beam Structure ............................................................................................................... 18
2.8.
Pivot Assembly .............................................................................................................. 20
2.9.
Hoist Assembly .............................................................................................................. 23
2.9.1.
Trolley Hoist ........................................................................................................... 24
2.9.2.
Hoist Selection Factors ........................................................................................... 24
2.9.3.
Selected Hoist ......................................................................................................... 26
2.9.4.
Hoisting Equipment ................................................................................................ 26
2.9.5. Hook Assembly........................................................................................................... 26
2.9.6. Gear Assembly ............................................................................................................ 27
2.9.7. Rope Drum .................................................................................................................. 27
2.9.8. Ropes........................................................................................................................... 28
2.9.9. Selection of Electric Motor ......................................................................................... 29
3.
2.10.
Detailed Description ................................................................................................... 29
2.11.
Drive Assembly .......................................................................................................... 30
Welding Analysis .................................................................................................................. 31
3.1.
General Instructions: ...................................................................................................... 31
3.2.
Welding Design .............................................................................................................. 32
3.2.1.
4.
Types of Weldings Used ......................................................................................... 33
3.3.
Beam Bracket Construction: .......................................................................................... 34
3.4.
Bottom Bracket Construction ......................................................................................... 34
3.5.
Tie Rod ........................................................................................................................... 36
3.6.
Crane Rail (Steel Supported Rail) .................................................................................. 37
3.6.1.
DIN “A” BURBACK rail ....................................................................................... 37
3.6.2.
Installation of rail .................................................................................................... 38
Hoist Motor ........................................................................................................................... 39
4.1.
Selection of Motor .......................................................................................................... 39
5.
Bearing Analysis (Slewing Bearing) .................................................................................... 40
5.1.
Material .......................................................................................................................... 41
5.2.
Components.................................................................................................................... 41
5.3.
Functioning and Analysis ............................................................................................... 42
5.4.
Attachment Bolts ............................................................................................................ 43
6.
Cost Analysis ........................................................................................................................ 43
6.1.
Trolley and Hoist Set...................................................................................................... 44
6.2.
H Beam ........................................................................................................................... 44
6.3.
Slewing Bearing ............................................................................................................. 45
6.4.
Welding and Bolts .......................................................................................................... 46
6.5.
Tie Rod ........................................................................................................................... 46
7.
Conclusion ............................................................................................................................ 47
APPENDICES .............................................................................................................................. 50
9.
Bill of Material ...................................................................................................................... 50
10.
ASTM BTH Standards ....................................................................................................... 51
11.
Manufacturing Details ....................................................................................................... 54
11.1.
H-Beam Manufacturing .............................................................................................. 54
11.2.
Hoist Manufacturing ................................................................................................... 54
11.3.
Hook Manufacturing................................................................................................... 55
11.4.
Trolley Manufacturing ................................................................................................ 55
11.5.
Tie Rod Manufacturing .............................................................................................. 56
11.6.
Bearing Manufacturing ............................................................................................... 56
12.
Cost Estimate ..................................................................................................................... 57
12.1.
Trolley and Hoist ........................................................................................................ 57
12.2.
H Beam ....................................................................................................................... 57
12.3.
Slewing Bearing ......................................................................................................... 58
12.4.
Welding and Bolts ...................................................................................................... 58
12.5.
Tie Rod ....................................................................................................................... 58
13.
Drawings ............................................................................................................................ 59
13.1.
Bracket Exploded View .............................................................................................. 64
13.2.
Crane Exploded View ................................................................................................. 65
List of Figures
Fig. 01: General Parts and Description of a Jib Crane .................................................................. 10
Fig. 02: Structural Concept of H-Type Jib Crane ......................................................................... 11
Fig. 03: Application of Forces ...................................................................................................... 12
Fig. 04 (a, b): Force Analysis........................................................................................................ 12
Fig. 05: Bending moment and Shear Force diagrams ................................................................... 14
Fig. 06: Moment of Inertia Calculation ........................................................................................ 15
Fig. 07: Push girder trolley-Single pin .......................................................................................... 16
Fig. 08: Crane trolley with 4 vertical flange wheels ..................................................................... 16
Fig. 09: Schematic Diagram for the cross-sections of an H-Beam ............................................... 18
Fig. 10: Moment Diagram of Crane Cantilever Beam .................................................................. 18
Fig. 11: Bracket Dimensions [In inches] ...................................................................................... 20
Fig. 12: Plumbing pivot mounting assembly ................................................................................ 21
Fig. 13: Orienting Bearing, Figure: Installing boom welding ...................................................... 21
Fig. 14: Installing upper pivot mounting assembly ...................................................................... 21
Fig. 15: Installing friction brakes on wall-mounted pivot assembly ............................................ 22
Fig. 16: Adjusting the secondary arm on wall-mounted pivot assembly...................................... 23
Fig. 17: Double girder crane hoist ................................................................................................ 23
Fig. 18: Hoist Assembly ............................................................................................................... 25
Fig. 19: Flow diagram for Crane Support Structure Design ......................................................... 30
Fig. 20: Drive Assembly ............................................................................................................... 31
Fig. 21: Single-flare-bevel-groove welds ..................................................................................... 33
Fig. 22: Single-flare-V-Groove Weld ........................................................................................... 33
Fig. 23: Joint Penetration Welds in Shear (Used for making rails runway) ................................ 33
Fig. 24: Beam Bracket Construction ............................................................................................. 35
Fig. 25 [a, b]: Bottom Brackets assembling with welding, bolt and bearing positions ................ 36
Fig. 26: Tie Rod with right hand threads on both ends ................................................................. 36
Fig. 27: Junction details ................................................................................................................ 37
Fig. 28: A soft mounted rail .......................................................................................................... 37
Fig. 29: BURBACK over steel support installation...................................................................... 38
Fig. 30: Welded joints in rails ....................................................................................................... 39
Fig. 31 (a): Motor Data of the drawings (Appendix) .................................................................... 39
Fig. 31(b): Dimensional Drawings ............................................................................................... 40
Fig. 32: Components of slewing bearing (Appendix)................................................................... 41
Fig. 33: Bolts positions in bearing and their lengths .................................................................... 43
List of Tables
Table 01: Specimen Standard Design Parameters ........................................................................ 19
Table 02: Sheaves and Drum Standard Values ............................................................................. 28
Table 03: Chemical Composition of E7018 Soldering Stick ........................................................ 32
Table 04: Mechanical Composition of E7018 Soldering Stick .................................................... 32
Table 05: Calculations for Welding Process ................................................................................. 32
Table 06: Some standard channel thicknesses .............................................................................. 34
Table 7: Flat bar welding .............................................................................................................. 37
Table 8: BURBACK over Steel Support Parameters ................................................................... 38
Table 09: Hoist Motor standards................................................................................................... 39
Table 10: Selection of bearing ...................................................................................................... 40
Table 11: Minimum Mechanical Characteristics of Bearing ........................................................ 42
Table 12: Track diameters and corresponding thicknesses........................................................... 42
Table 13: Standard Tolerances (ISO 286-2 Standard) .................................................................. 43
1. Problem Definition
1.1.
Problem Scope
While working in industry, especially in mechanical field, we deal with a lot of heavy load.
Heavy loads include any machinery with engine power mechanism, any vehicle like car, trolley
or van. This is the case when we intentionally use cranes for moving them when these things are
not movable on their own. Moreover, we also deal with accidents everywhere. When huge loads
are disturbed accidently, then cranes are also employed to deal with these accidently fallen loads.
Jib cranes are basically kind of overhead cranes. These cranes have a large horizontal arm and
are fixed with the wall, or earth via long column, to lift a load in a particular defined range of the
arm. These types of cranes have a big application that these are highly used for construction
purposes. Hospitals, Banks, Plazas etc are all constructed by the assistance of jib cranes. These
are also called as tower cranes.
1.2.
Technical Review
When I talk about technical review, then I am going to deal with the structural components and
its technical specifications. Main structural components of the crane are boom or a particular
type of Beam, tie rod, brackets, gusset and trolley. Length of boom is called span and it is usually
6 to 8 meters, I have 7.25 m in my case. Bolts and welding are also used while assembling these
components. Technical design and detail of each component shall be discussed in further
sections of this report.
1.3.
Design Requirements
I am going to design a “Wall-mounted Jib Crane” with H-type.
2. Design Description
2.1.
Overview
Actually, a unique power drive (electric) with built in adjustable clutch is used to power the
crane. There is a “VFD” Controller Rotation Panel attached to the motor. Slewing power is
transmitted by gears i.e. pinion and ring gear. Collector rings and cable grip is provided for the
given rotation i.e. 300 degrees. The hoists and trolleys of jib cranes are slow moving with a
manual travelling mode whereas slewing is motor controlled. Brackets shall be used to connect
crane on the wall.
Fig. 01: General Parts and Description of a Jib Crane (Design Concepts for Jib Cranes, n.d.)
2.2.
Structural Components
The main components with some specified details are highlighted below:
Fig. 02: Structural Concept of H-Type Jib Crane (H Beam Design, n.d.)
2.3.
Applied forces to the supported structure
When we talk about wall-mounted jib crane, then there is no need to use mast. Only wall
brackets are used where there are two kinds of forces exerted; pull on one bracket and thrust on
the other. As applied load is towards down, hence tie rod will tend to extend itself which will
exert a pull on bracket. A thrust will be generated on the other bracket to accommodate this pull.
Fig. 03: Application of Forces (Design Concepts for Jib Cranes, n.d.)
2.3.1. Loading Calculations
(a)
Angle between tie rod and boom is kept low; let us assume it to be 10 degrees, then;
(b)
Fig. 04 (a, b): Force Analysis (Design Concepts for Jib Cranes, n.d.)
Here,
A = Span = 7.25 m
P = Maximum load = 1850 kg = Resultant
Acting at top hinge only;
1
𝐴
𝐹𝐻 = [π‘Šπ‘™π‘–π‘“π‘‘π‘’π‘‘ + π‘Šπ΅π‘œπ‘œπ‘š + π‘Šπ‘‡π‘Ÿπ‘œπ‘™π‘™π‘’π‘¦ ] π‘π‘œπ‘  ( ) , … … … (1)
2
𝐡
π‘ˆπ‘ π‘–π‘›π‘”,
tan πœƒ =
𝐡
𝐴
𝐡 = 𝐴 tan πœƒ = (7.25π‘š) × tan 10 = 1.278 π‘š
𝑩 = 𝟏. πŸπŸ•πŸ– π’Ž
Hence, using equation (1);
𝐹𝐻 = (18148.5) × π‘π‘œπ‘  (
7.25
)
1.278
𝑭𝑯 = πŸπŸ•πŸ–πŸ•πŸ. πŸ•πŸ– 𝑡
Now, for vertical forces, we can write:
1
𝐴
𝐹𝑣 + 𝐹𝑏 = [π‘Šπ‘™π‘–π‘“π‘‘π‘’π‘‘ + π‘Šπ΅π‘œπ‘œπ‘š + π‘Šπ‘‡π‘Ÿπ‘œπ‘™π‘™π‘’π‘¦ ] ( ) , . … … … … (2)
2
𝐸
π»π‘œπ‘–π‘ π‘‘
Let us assume that sum of lifted weight, boom weight and trolley weight is equal to the capacity
of the crane and is given as (1850 x 9.81) N. Also let us consider A=E, hence we can write:
π‘Šβ„Žπ‘’π‘Ÿπ‘’,
𝑭𝒗 = π‘·π’”π’Šπ’ (𝟏𝟎) = πŸπŸ–πŸπŸ’πŸ–. πŸ“ 𝐬𝐒𝐧(𝟏𝟎) = πŸ‘πŸπŸ“πŸ. πŸ’πŸ“ 𝑡
𝐹𝑣 + 𝐹𝑏 = 1850 × 9.81 π‘œπ‘Ÿ 3151.45 + 𝐹𝑏 = 1850 × 9.81
𝑭𝒃 = πŸπŸ’πŸ—πŸ—πŸ•. πŸŽπŸ“ 𝑡
2.4.
Moment and Shear diagrams
Considering impact factor of 1.3, we can write bending moment as:
πΌπ‘šπ‘π‘Žπ‘π‘‘ 𝐡𝑒𝑛𝑑𝑖𝑛𝑔 π‘€π‘œπ‘šπ‘’π‘›π‘‘ = 1.3 × π‘ƒπ‘¦ × π΄
Where
P y = Maximum vertical load = P sin 𝜽 = 18148.5 (sin 10) = 3151.45 N
A = span length = 7.25 m
π‘°π’Žπ’‘π’‚π’„π’• π‘©π’†π’π’…π’Šπ’π’ˆ π‘΄π’π’Žπ’†π’π’• = 𝟏. πŸ‘ × πŸ‘πŸπŸ“πŸ. πŸ’πŸ“ × πŸ•. πŸπŸ“ = πŸπŸ—πŸ•πŸŽπŸ. πŸ’πŸ π‘΅π’Ž
Maximum Shear force is constant due to a point load and hence given as:
π‘‰π‘šπ‘Žπ‘₯ = 𝑃𝑦 = 18148.5 sin(10) = 3151.45 𝑁
Maximum bending moment can be written as
π‘€π‘šπ‘Žπ‘₯ = 𝑃𝑦 𝐴 = 3151.45 × 7.25 = 22848.013 𝑁
Fig. 05: Bending moment and Shear Force diagrams (Shear forces and Bending Moment
Diagrams, n.d.)
2.5.
Deflection in the Beam
Considering boom section as an H-beam section, we can label and write the moment of inertia:
Fig. 06: Moment of Inertia Calculation (H Beam Moment of Inertia, n.d.)
2𝑏𝐻 3 + π‘‘β„Ž3
π‘€π‘œπ‘šπ‘’π‘›π‘‘ π‘œπ‘“ π‘–π‘›π‘’π‘Ÿπ‘‘π‘–π‘Ž = 𝐼 =
12
Width and thickness can be taken equal and equal to 0.5’, hence B = H = 0.1524 m, thickness is
taken as 0.5 inch, hence b = 0.0127 m, h = 2b = 0.0254 m, d = 0.127 m
2𝑏𝐻 3 + π‘‘β„Ž3 2(0.0127)(0.1524)3 + (0.127)(0.0254)3
𝐼=
=
12
12
𝐼 = 7.66 × 10−6 π‘š4
Material = ASTM A36 Steel
Modulus of Elasticity = E = 200 GPa
Using deflection formula for cantilever beam, maximum deflection with full load is:
π‘’π‘šπ‘Žπ‘₯ =
π‘’π‘šπ‘Žπ‘₯
𝑃𝐴3
3𝐸𝐼
(18148.5)(7.25)3
=
3(200 × 109 )(7.66 × 10−6 )
π‘’π‘šπ‘Žπ‘₯ = 1.505 π‘š
This value is much greater than expected; hence tie rods are essential for this kind of crane.
When we will use tie rod, then load will be divided into components. Vertical component will be
responsible for the deflection:
π‘’π‘šπ‘Žπ‘₯
′
𝑃𝑦 𝐴3
18148.5 𝑠𝑖𝑛(10)(7.25)3
=
=
3𝐸𝐼
3(200 × 109 )(7.66 × 10−6 )
π’–π’Žπ’‚π’™ ′ = 𝟎. πŸπŸ”πŸ π’Ž = πŸπŸ”πŸ π’Žπ’Ž
Boom will undergo 261 mm of deflection when loaded fully, which is acceptable.
2.6.
Trolley Design
Trolley could be a unit that carries the hoisting mechanism that travels on the bridge rails in the
direction perpendicular to the Crane runway. Crane trolley frame is actually the basic structure of
the trolley on that the hoisting and traversing mechanisms are mounted.
Fig. 07: Push girder trolley-Single pin (Hoist and trolley full catalog, n.d.)
Fig. 08: Crane trolley with 4 vertical flange wheels (final load distribution trolley beam twocrane picks)
Here,
𝑍𝑗 = π‘€β„Žπ‘’π‘’π‘™ π‘£π‘’π‘Ÿπ‘‘π‘–π‘π‘Žπ‘™ π‘“π‘œπ‘Ÿπ‘π‘’π‘ 
𝑙 = π‘π‘Ÿπ‘Žπ‘›π‘’ π‘ π‘π‘Žπ‘›
π‘β„Ž = π‘Ÿπ‘Žπ‘–π‘™ β„Žπ‘’π‘Žπ‘‘ π‘€π‘–π‘‘π‘‘β„Ž
𝑀𝑏 = π·π‘–π‘ π‘‘π‘Žπ‘›π‘π‘’ 𝑏𝑒𝑑𝑀𝑒𝑒𝑛 π‘‘β„Žπ‘’ 𝑔𝑒𝑖𝑑𝑒 π‘šπ‘’π‘Žπ‘›π‘ 
𝑑𝑗 = π‘‘π‘–π‘ π‘‘π‘Žπ‘›π‘π‘’ π‘“π‘Ÿπ‘œπ‘š π‘‘β„Žπ‘’ 𝑔𝑒𝑖𝑑𝑒 π‘šπ‘’π‘Žπ‘›π‘  π‘‘π‘œ π‘‘β„Žπ‘’ π‘€β„Žπ‘’π‘’π‘™ 𝑗
π‘Šβ„Žπ‘’π‘Ÿπ‘’,
πΉπ‘œπ‘Ÿπ‘π‘’ π‘œπ‘› π‘‘β„Žπ‘’ 𝑔𝑒𝑖𝑑𝑒 π‘šπ‘’π‘Žπ‘›π‘  = π‘ŒπΉ = ∑ π‘Œπ‘—
π‘€π‘–π‘›π‘–π‘šπ‘’π‘š π‘Ÿπ‘’π‘π‘œπ‘šπ‘šπ‘’π‘›π‘‘π‘’π‘‘ π‘‘π‘Ÿπ‘œπ‘™π‘™π‘’π‘¦ π‘‘π‘Ÿπ‘Žπ‘π‘˜ π‘π‘™π‘’π‘Žπ‘Ÿπ‘Žπ‘›π‘π‘’ π‘£π‘Žπ‘™π‘’π‘’ = π‘ π‘”π‘šπ‘–π‘› = 4 π‘šπ‘š
πΉπ‘Ÿπ‘œπ‘š π‘“π‘–π‘”π‘’π‘Ÿπ‘’, 𝑀𝑒 π‘˜π‘›π‘œπ‘€ π‘‘β„Žπ‘Žπ‘‘,
𝑆 = 𝑍1 + 𝑍2 + 𝑍3 + 𝑍4
𝑆𝑑 = 𝑍1 𝑑1 + 𝑍2 𝑑2 + 𝑍3 𝑑3 + 𝑍4 𝑑4
𝑆𝑑𝑑 = 𝑍1 𝑑1 2 + 𝑍2 𝑑2 2 + 𝑍3 𝑑3 2 + 𝑍4 𝑑4 2
𝐻𝑒𝑛𝑐𝑒,
π‘‡β„Žπ‘’π‘Ÿπ‘’π‘“π‘œπ‘Ÿπ‘’,
𝑏=
𝑆𝑑
𝑆𝑑𝑑
πΏπ‘Žπ‘‘π‘’π‘Ÿπ‘Žπ‘™ π‘“π‘œπ‘Ÿπ‘ π‘’ π‘Žπ‘‘ π‘‘β„Žπ‘’ 𝑔𝑒𝑖𝑑𝑒 π‘šπ‘’π‘Žπ‘›π‘  𝐹𝑦 = π‘ŒπΉ = 𝑒𝑓 (𝑆 − 𝑆𝑑 𝑏)
Where, “u f” is friction slip coefficient. This is a design procedure for the trolley. Some selected
standard values have been mentioned in the table attached in appendix (Table 01, Table 03).
2.7.
Beam Structure
Let us consider an H-Beam with the following nomenclature:
Fig. 09: Schematic Diagram for the cross-sections of an H-Beam (H Beam Calculations, n.d.)
Fig. 10: Moment Diagram of Crane Cantilever Beam (H Beam Calculations, n.d.)
Where, d=depth, b= width, t
thickness can be obtained as:
w
= web thickness and t f = flange thickness. Minimum wing plate
Where, Z0 is Plastic Modulus and S0 is Section modulus of the beam. These can be found by:
Let us consider that Ls is length of welding zone and L b is length of span i.e. 7.25 m, hence
π·π‘’π‘šπ‘Žπ‘›π‘‘ π‘€π‘œπ‘šπ‘’π‘›π‘‘ = π‘€π·π‘’π‘šπ‘Žπ‘›π‘‘ =
𝐿𝑏
𝑀
𝐿𝑏 − 𝐿𝑠 𝑝
Where, M p is plastic moment and it can be measured by using:
𝑀𝑝 = 𝐹𝑦 𝑍0
Where, “F y” is a yielding stress of steel.
Table 01: Specimen Standard Design Parameters (ASME B16.21-2011 (Revision of ASME
B16.21-2005) Nonmetallic flat gaskets for pipe flanges, n.d.)
Some standard values for the H-Beam structure are given in the appendix (Table 04 and Table
05)
2.8.
Pivot Assembly
Pivot assembly is very essential towards boom installation. Here are some steps required to make
pivot assembly for boom installation:
Fig. 11: Bracket Dimensions [In inches] (Hoist and trolley full catalog, n.d.)
Determine the position of upper pivot mounting assembly on the support structure, and drill bolt
holes. Quickly bolt the upper pivot mounting assembly to the support structure (don’t use lock
washers).
Determine position of lower pivot mounting assembly by dropping bob (by others) through pivot
holes
Drill bolt holes and bolt lower pivot mounting assembly to support structure. Don’t force bolts
till boom assembly is put in.
Remove the upper pivot mounting assembly from support structure.
Fig. 12: Plumbing pivot mounting assembly (Hoist and trolley full catalog, n.d.)
Clean pivot pins with a clean, dry cloth. Slide the bearings on pivot pins. Ensure to orient
bearings properly.
Lift boom weldment up and insert lower pivot pin into lower pivot mounting assembly
Fig. 13: Orienting Bearing, Figure: Installing boom welding (mediathek, n.d.)
Place higher pivot mounting assembly on higher pivot pin of boom assembly Bolt higher pivot
mounting assembly to support structure.
Fig. 14: Installing upper pivot mounting assembly (Hoist and trolley full catalog, n.d.)
At 45° intervals, make sure pivot pins of crane are plumb. Shimming of higher and/or lower
pivot mounting assembly is also needed (shims included).
Once pins are plumb and shimmed, tighten all mounting bolts to manufacturer’s specifications.
Carefully swing boom through entire journey and guarantee boom is obvious of obstructions and
doesn't drift. If boom drifts, support structure is also inadequate and/or pivot mounting assembly
might not be aligned
Attach 2 brake pads to the lower pivot mounting assembly by using two 1/4” socket head cap
screws, lock washers, and lock nuts.
Fig. 15: Installing friction brakes on wall-mounted pivot assembly (mediathek, n.d.)
Adjust brake by alteration 2 lock nuts to get the desired motility resistance of the first arm.
To adjust the secondary arm, loosen the set screw and jam nut.
Adjust set screw for desired motility resistance.
Tighten the jam nut.
Fig. 16: Adjusting the secondary arm on wall-mounted pivot assembly (mediathek, n.d.)
2.9.
Hoist Assembly
A hoist may be a device used for lifting or lowering a load with the help of a drum or lift-wheel
around that the rope or chain is wrapped. Cranes and Hoists are somewhat interchangeable things
since the particular lifting mechanism of a crane is usually stated as a hoist. Hoists could also be
integral to a crane or mounted in a fixed position, temporarily or permanently. Once a hoist is
mounted to a self-propelled trolley on a single rail system, 2 directions of load motion are
available i.e. forward or reverse, up or down. Once the hoist is mounted on a crane, 3 directions
of load motion are available i.e. right or left, forward or reverse, up or down.
The hoist mechanism may be a unit consisting of a motor drive, coupling, brakes, gearing, drum,
ropes, and cargo block designed to lift, hold and lower the most rated load. Hoist mechanism is
mounted on the trolley.
Fig. 17: Double girder crane hoist (Hoist and trolley full catalog, n.d.)
2.9.1. Trolley Hoist
An electric hoist and high running motorized self-propelled vehicle i.e. trolley combined in one
unit provides correct load positioning during a kind of applications. Wheels, drives and
management packages are unremarkably designed specifically for the appliance. Out there to be
used on category A through D cranes having capacities from five tons to thirty tons with normal
lifts of a hundred feet or additional.
Common Applications: Moderate service together with significant machine retailers, metal
fabricating plants and steel reposition.
Selection Considerations: Sturdy, welded steel frame; back-geared limit switches; variable
hoist and self-propelled vehicle speeds and controls; heat treated wheels; heavy-duty crane rated
motors; double reeving for true vertical lift; heavy-duty, long bearings.
2.9.2. Hoist Selection Factors
1) The load to be upraised together with below-the-hook lifting, load supporting, and
positioning devices.
2) Physical size of the load.
ο‚·
Holding and orienting devices.
ο‚·
Design for centre of gravity (control & stability).
ο‚·
Lift – the vertical distance the load will be affected.
3) Clearance concerns
ο‚·
Headroom
ο‚·
Obstacles to be cleared throughout the load transfer.
ο‚·
Design for vertical raise needed together with device height.
4) Lifting Speed concerns
ο‚·
Distance the load is to be raised and down
ο‚·
Frequency of usage
ο‚·
Required positioning accuracy
ο‚·
Nature of the load being upraised
5) Hoist duty Cycle concerns based mostly on:
ο‚·
Number of lifts per hour
ο‚·
Total range of lifts per shift
ο‚·
Maximum range of starts and stops per hour
ο‚·
Number of shifts per day
ο‚·
Average distance load is raised and down
ο‚·
Average weight to be upraised
ο‚·
Maximum weight to be upraised
ο‚·
Frequency of lifts with most weight.
Fig. 18: Hoist Assembly (Hoist and trolley full catalog, n.d.)
2.9.3. Selected Hoist
Hoist Name: Overhead Electric Wire Rope Hoist
Standard: ASME-HST-4
2.9.4. Hoisting Equipment
Sheaves
A “Sheave” may be a grooved wheel or pulley-block used with a rope or chain to vary direction
and purpose of application of an actuation force.
Load Block
Load Block is associated with an assembly of hook, swivel, bearings, sheaves, pins and frame
suspended from the hoisting ropes. In a "short type" block, the hook and also the sheaves are
mounted on a similar member, referred to as the swivel. However, in a "long type" block, the
hook and also the sheaves are mounted on separate members.
The supporting member for the sheaves is termed as the sheave pin and also the supporting
member for the hook is termed as the trunnion.
2.9.5. Hook Assembly
1) Load blocks and hook assembly shall be non-sparking, non-corroding kind, fictional of AISI
kind304, 18-8 chrome-nickel, corrosion-resistant steel or a bronze alloy of appropriate strength
and section for the rated capability load. Hook material will be cast steel for non-hazardous
areas.
2) Hook assembly for electrical hoists shall be carried on antifriction bearings to allow free
swivel below rated-capacity load while not twisting load chain or wire.
3) Every hook assembly shall embrace a machined and rib shaft and swivel nut with an efficient
lockup device to stop nut from backing off.
4) Every hook shall have an elastic device safety latch.
2.9.6. Gear Assembly
1) Gear shafts shall be factory-made from high-carbon steel or steel, machined and ground for
correct work and splined for fitting to the union gear.
2) Gear-train assembly shall be carried on antifriction bearings and encircled within the hoist
frame casting.
Assembly shall operate during a sealed oil tub.
3) Frame casting shall be supplied with lubrication fittings and review ports.
2.9.7. Rope Drum
Selection of rope will be made in line with the quality knowledge out there in appendix (Table
02).
1) Rope drum shall be hardened steel or special-grade forged iron.
2) Drum shall have correct, machine-cut grooves, move full depth of wire-rope radius, with
rounded corners of dimension as needed for the indicated raise. Groove diameter and pitch
centers shall be not but 1/32 in. (0.79mm) bigger than diameter of rope.
Table 02: Sheaves and Drum Standard Values (ASME B16.21-2011 (Revision of ASME B16.212005) Nonmetallic flat gaskets for pipe flanges, n.d.)
2.9.8. Ropes
In selecting hoisting ropes, the Crane manufacturer's recommendation shall be followed. The
rated load divided by the quantity of components of rope shall not exceed twenty % of the
nominal breaking strength of the rope.
1) Wire rope for normal applications shall be further versatile, preformed, and improved, plow
steel, 6 by37, fiber-core wire conformist to FS RR-W-410, Type I, Class 3.
2) Wire rope for single-line application shall be performed, improved plow steel, 18 by 7, fibercore, non-rotating wire conformist to FS RR-W-410, Type IV, and sophistication a pair of.
3) Wire rope for non-corroding, non-sparking hoist application shall be performed, AISI kind
304, 18-8 corrosion-resistant steel, 6 by 19, bright end, conformist to FS RR-W-410, Type I,
Class 2.
4) Wire rope shall have a FOS (Factor of Safety) of not less than five, based on the minimum
final strength of the fabric used, for different classes of cranes like A and B cranes, and a factor
of safety of six for Category C cranes.
5) Not less than 3 wraps of rope shall stay on the drum once the hook is in its extreme low
position and make sure that one extra rope flip will be accommodated once the hook is at its
higher limit of hoisting (i.e. the rope shall not overlap once the hook is at its highest point).
2.9.9. Selection of Electric Motor
Let us assume that lifting speed varies from 50 to 130 mm/s.
π‘ƒπ‘œπ‘€π‘’π‘Ÿ = 𝑷 =
2πœ‹π‘π‘‡
60
Speed of drum = ω = 4 x 0.13/R = 2N
For drum rotating angular speed ω, we can write:
π‘ƒπ‘œπ‘€π‘’π‘Ÿ = 𝑷 = π‘‡πœ” = π‘ƒπ΄πœ” = (18148.5)(7.25)(4π‘₯0.13)
π‘·π’π’˜π’†π’“ = 𝑷 = πŸ”πŸ–πŸ’πŸπŸ—. πŸ–πŸ’πŸ“ 𝑾𝒂𝒕𝒕 = πŸ”πŸ–. πŸ’πŸ π’Œπ‘Ύ
2.10. Detailed Description
There is a particular procedure that must be followed before making a crane structure. There are
some considerations which are of primary importance and these can’t be ignored. Primary level
requirements include the codes and standards, loading, the steel structure design, clearances and
Earthworks. Earth works must be done on the soil to make sure that it can bear heavy loads.
Fig. 19: Flow diagram for Crane Support Structure Design (Thompson, n.d.)
2.11. Drive Assembly
There are two requirements that must be fulfilled before selecting wall bracket jib crane:
1) There should be a structurally adequate wall, column or truss to support the crane. Note
that the responsibility for determining if the support is adequate or not, rests entirely on
the customer. Information on the loading of the support by the crane can be found by
checking the manufacturer’s guides for cranes e.g. WB100.
2) There should be sufficient clearance (nominally 3 inches) above the tie rod throughout its
arc.
Before selecting wall brackets, tie rod, drive motor and rotation arm, we should know the
mechanism to be utilized for making the drive assembly. General mechanism can be seen in the
figure below:
Fig. 20: Drive Assembly (Wall mounted jib crane, n.d.)
3. Welding Analysis
3.1.
General Instructions:
οƒΌ All welds should have 4 mm fillet
οƒΌ All bolts should be M16 or higher
οƒΌ Gusset Plates must be 8 mm thick
οƒΌ Internal bracing shown 65 x 50 x 6 to use common section (Size can be reduced if others
available)
οƒΌ All sections should be in grade 43 steel
οƒΌ Purlin supports: 70 x 70 x 6 with 2 x 6 Ø holes.
3.2.
Welding Design
(Structural Fabrication Materialsof crane = CCT38 and ASTM A36 Steels)
Type of Welding = Automatic Welding (Electric Arc Welding)
Welding Quality = Uniform metal welding of chemical composition is high
Electrodes = Low-Hydrogen Welding Electrodes (Welding rods must be thoroughly dry)
Soldering Stick (Standard E7018)
Table 03: Chemical Composition of E7018 Soldering Stick (Book, n.d.)
Table 04: Mechanical Composition of E7018 Soldering Stick (Book, n.d.)
Table 05: Calculations for Welding Process (Book, n.d.)
3.2.1. Types of Weldings Used
Fig. 21: Single-flare-bevel-groove welds (Design for Welding, n.d.)
Fig. 22: Single-flare-V-Groove Weld (Design for Welding, n.d.)
Fig. 23: Joint Penetration Welds in Shear (Used for making rails runway) (Welding
guidlines, n.d.)
3.3.
Beam Bracket Construction:
ο‚·
It connects tie rod to the beam near end of span.
ο‚·
It consists of a formed clevis fastened to the tie rod, and bolted to the formed beam
channel.
ο‚·
Design does not rely on any tension welds
ο‚·
Pivot bolt is in double shear
3.4.
Bottom Bracket Construction
1) Bottom bracket accepts the downward and compressive forces which actually crane
applies, yet provides optional ease of rotation and resistance to drift the boom.
2) It has a formed channel which is bolted to the supporting structure.
3) It has two beam connecting plates that are welded to a steel tube, which contains two
bronze bushings.
4) The bolts that connect the plates to the beam are in double shear, with a minimum
dependency on welds in carrying the load.
5) The beam bracket assembly normally rests on an oil-impregnated bronze thrust washer
and is held in a formed wall channel by using a pivot bolt assembly that is in double
shear.
6) A grease fitting is also provided for field lubrication.
Table 06: Some standard channel thicknesses (Welding guidlines, n.d.)
Fig. 24: Beam Bracket Construction (Behavior of welded CFT column to H-beam connections
with external stiffeners, n.d.)
(a)
(b)
Fig. 25 [a, b]: Bottom Brackets assembling with welding, bolt and bearing positions
(Behavior of welded CFT column to H-beam connections with external stiffeners, n.d.)
3.5.
Tie Rod
i.
A single tie rod made up of ASTM A36 and right hand threaded at each end is used.
ii.
Tie rod offers ease of leveling
iii.
It assures that the bottom bracket and H-Beam will be loaded evenly.
iv.
The design of single tie rod is superior to a double tie rod arrangement that depends on
even adjustments of the two tie rods, which can increase installation time as well as costs.
Fig. 26: Tie Rod with right hand threads on both ends (abus overhead cranes, n.d.)
3.6.
Crane Rail (Steel Supported Rail)
Table 7: Flat bar welding (Design for Welding, n.d.)
Fig. 27: Junction details (Design for Welding, n.d.)
3.6.1. DIN “A” BURBACK rail
Fig. 28: A soft mounted rail (Wall mounted jib crane, n.d.)
Rail profile must fulfill the requirements of DIN 536 and should have minimum tensile strength
of 650 MPa.
Length of each portion should be big enough in order to reduce the number of junctions.
3.6.2. Installation of rail
Fig. 29: BURBACK over steel support installation (Wall mounted jib crane, n.d.)
Table 8: BURBACK over Steel Support Parameters (Thompson, n.d.)
Fig. 30: Welded joints in rails (Design for Welding, n.d.)
4. Hoist Motor
4.1.
Selection of Motor
Standard: Crane and Hoist Duty Motors Type MC Foot Mounted (B3) TEFC Series
Type of Frame: Frame 355L
Table 09: Hoist Motor standards (crane hoist duty motors catalog, n.d.)
Fig. 31 (a): Motor Data of the drawings (Appendix)
Fig. 31(b): Dimensional Drawings (crane hoist duty motors catalog, n.d.)
5. Bearing Analysis (Slewing Bearing)
Slewing Bearing is a main component used in jib cranes. It is responsible to reduce friction in
slewing. When crane slews or turns at a certain angle like 300 degrees in our case, this bearing
turns out to be an essential part to help this rotation. It basically contains two rings, one inside
and one outside. A lubricant is added between these two rings to reduce friction.
Table 10: Selection of bearing
5.1.
Material
Steel is used as a basic manufacturing material. Different alloys of steel are prepared for better
strength. These materials are specially prepared for this purpose.
5.2.
Components
Fig. 32: Components of slewing bearing (Appendix)
5.3.
Functioning and Analysis
Table 11: Minimum Mechanical Characteristics of Bearing
Table 12: Track diameters and corresponding thicknesses
Table 13: Standard Tolerances (ISO 286-2 Standard)
5.4.
Attachment Bolts
Where,
Fig. 33: Bolts positions in bearing and their lengths (Appendix)
6. Cost Analysis
Cost estimation for each part of the crane will be done according to the companies recently
manufacturing these parts. Complete cost and product details shall be provided in this section
along with their references from reliable sources.
6.1.
Trolley and Hoist Set
Trolleys with complete hoist are easily available in market. It can be selected by visiting
companies who produce different kinds of crane trolleys. We have got a similar hoist and trolley
assembly which also includes hoist motor as well as hook assembly.
CD Electric Wire rope hoist has only one normal speed whereas MD Electric wire rope hoist
gives two speeds i.e. normal and low speed. At a low speed, it can do precise loading and
unloading.
Reference:https://www.alibaba.com/product-detail/2-ton-3-ton-5ton_1491014450.html?spm=a2700.7724838.2017115.32.4b0e4059nOE9Fo
6.2.
H Beam
We have found some companies who manufacture H-Beams of different dimensions. We can
easily select one beam of our desired dimensions. The minimum price we can get for a 7.25 m
long H beam is $550.
The selected company produces H-Beams with lengths 6m to 12 m and flange width of 100 mm
to 900 mm hence we can get our desired beam section here.
Reference:https://www.alibaba.com/product-detail/China-manufacturer-construction-structuralH-beam_60772883253.html?spm=a2700.7724838.2017115.126.4b0e4059nOE9Fo
6.3.
Slewing Bearing
Reference:https://www.alibaba.com/product-detail/hydraulic-marine-crane-jib-craneslewing_1950500507.html?spm=a2700.7724838.2017115.1.39b02f0a28cETe&s=p
6.4.
Welding and Bolts
Reference:https://www.alibaba.com/product-detail/high-pressure-stud-bolt-arcwelding_60509355067.html?spm=a2700.7724838.2017115.28.39b02f0a28cETe&s=p
6.5.
Tie Rod
Reference:https://www.alibaba.com/product-detail/Formwork-parts-Self-color-Galvanizingsteel_60624521291.html?spm=a2700.7724838.2017115.11.64867cd0RWsClm&s=p
7. Conclusion
Some required specifications, given by the client, have been utilized to design a particular jib
crane. The designed H-Type jib crane has maximum capacity of 1850 kg, a span length of 7.25
meters, maximum height of 8 meters and slewing angle is 300 degrees. Travelling mode is
manual i.e. the movement of trolley is controlled manually whereas slewing mode is motor
controlled i.e. left right turning movement of the beam shall be controlled by motor. After
considering all parameters, it has been calculated that hoist motor should have a power of 68 kW
or higher to lift the maximum desired capacity load.Detailed Engineering Drawings were made
and are attached in the Appendix. All drawings were made in SolidWorks 2016. Main
components, which were considered in making drawings, were H-Beam, Trolley Assembly and
Hoist Assembly, Tie rod, Wall Brackets and Fasteners like nuts and bolts. Standard dimensions
were used and all dimensions can be seen mentioned in the drawing files.
8. References
[1] abus
overhead
cranes.
(n.d.).
Retrieved
from
www.abuscranes.com:
https://www.abuscranes.com/download/ac79cd9ff7e1eb9da9d1c851bc67fb50/abus_overh
ead_cranes.pdf
[2] ASME B16.21-2011 (Revision of ASME B16.21-2005) Nonmetallic flat gaskets for pipe
flanges. (n.d.). Retrieved from b-ok: http://b-ok.xyz/book/2075926/2c6bb0
[3] Behavior of welded CFT column to H-beam connections with external stiffeners. (n.d.).
Retrieved from ar.booksc.org: http://ar.booksc.org/book/3023206/ad4efd
[4] Book, E. (n.d.). ASM Metals Handbook, Vol 02 Properties and Selection: Nonferrous
Alloys
and
Special-Purpose
Materials.
Retrieved
from
b-ok:
http://www.b-
ok.xyz/book/542821/aaeeae
[5] crane
hoist
duty
motors
catalog.
(n.d.).
Retrieved
from
http://www.bharatbijlee.com/media/13634/crane_hoistdutymotorscatalogue.pdf
[6] Design
Concepts
for
Jib
Cranes.
(n.d.).
Retrieved
from
Scribd:
https://www.scribd.com/document/356475547/Design-Concepts-for-Jib-Cranes-pdf
[7] Design
for
Welding.
(n.d.).
Retrieved
from
lecturer.ppns.ac.id:
http://lecturer.ppns.ac.id/munir/wp-content/uploads/sites/14/2015/09/71005378-Designfor-Welding.pdf
[8] final load distribution trolley beam two-crane picks. (n.d.). Retrieved from www.iti.com:
https://www.iti.com/hs-fs/hub/78935/file-705583916-pdf/docs/~final_load_distribution__trolley_beam__two-crane_picks_042914r1.pdf
[9] H
Beam
Calculations.
(n.d.).
Retrieved
from
ar.booksc.org:
from
ar.booksc.org:
http://ar.booksc.org/s/?q=H+beam+calculations&t=0
[10]
H
Beam
Design.
(n.d.).
Retrieved
http://ar.booksc.org/s/?q=H+beam+design&t=0
[11]
H
Beam
Moment
of
Inertia.
https://www.pinterest.co.uk/pin/349169777339870818/
(n.d.).
Retrieved
from
[12]
Hoist and trolley full catalog. (n.d.). Retrieved from www.cmworks.com:
https://www.cmworks.com/Public/11144/Hoist%20and%20Trolley%20Full%20Catalog.
pdf
[13]
how to calculate the load capacity of a jib crane. (n.d.). Retrieved from hunker:
https://www.hunker.com/12462977/how-to-calculate-the-load-capacity-of-a-jib-crane
[14]
mediathek.
(n.d.).
Retrieved
from
www.gis-ag.ch:
https://www.gis-
ag.ch/mediathek/pdf/englisch/05-laufkran-englilsch/laufkrane_en.pdf
[15]
Shear forces and Bending Moment Diagrams. (n.d.). Retrieved from
notendur.hi.is: https://notendur.hi.is/mvg1/ch4.pdf
[16]
Thompson.
(n.d.).
Structural
Design. Retrieved from scholar.sun.ac.za:
https://scholar.sun.ac.za/bitstream/handle/10019.1/1904/Thompson,%20G.B.pdf?sequenc
e=1
[17]
wall mounted cantilever jib cranes. (n.d.). Retrieved from cisco eagle:
http://www.cisco-eagle.com/catalog/category/4343/wall-mounted-cantilever-jib-cranes
[18]
Wall mounted jib crane. (n.d.). Retrieved from Supporting Structures:
http://smakmanutention.com/products/supportings-structures/Wall-mounted-Jib-crane/
[19]
Welding
guidlines.
(n.d.).
Retrieved
from
homepages.cae.wisc.edu:
http://homepages.cae.wisc.edu/~me349/lecture_notes/welding_guidelines.pdf
APPENDICES
9. Bill of Material
Sr. No.
Name of Component
Quantity
Material
1.
Crane Hook
1
Wrought Iron
2.
Trolley
1
Cast Iron Body
3.
Hoist
1
Carbon Steel
4.
H-Beam
1
Carbon Steel
5.
Tie Rod
1
Mild Steel
6.
Bolts and Nuts
(for each hole)
Alloy steel
7.
Rope
1
Steel Wires
8.
Slewing Bearing
1
Carbon Steel
Internal Gears
2
Case Hardened Cast
9.
Iron
10.
ASTM BTH Standards
Table I: Basic Crane Data
Table II: Selection of rope
Table III: Push Girder Trolley Standard Dimensions
Table IV: Suggested Wing Plate widths
Table V: Plastic Shear Forces
Table VI: minimum effective Throat for Partial joint Penetration groove welds in steel
Table VII: Hoist Motor Data
11.
Manufacturing Details
11.1. H-Beam Manufacturing
11.2. Hoist Manufacturing
11.3. Hook Manufacturing
11.4. Trolley Manufacturing
11.5. Tie Rod Manufacturing
11.6. Bearing Manufacturing
12.
Cost Estimate
12.1. Trolley and Hoist
12.2. H Beam
12.3. Slewing Bearing
12.4. Welding and Bolts
12.5. Tie Rod
13.
Drawings
13.1. Bracket Exploded View
13.2. Crane Exploded View
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