See discussions, stats, and author profiles for this publication at: https://www.researchgate.

net/publication/331154663

Design and Analysis of Bushed Pin Flexible Coupling

Article · April 2017

CITATIONS READS

3 24,191

1 author:

Timur Choban Khidir

Kirkuk University
17 PUBLICATIONS   9 CITATIONS   

SEE PROFILE

Some of the authors of this publication are also working on these related projects:

Online and Distance Learning View project

Design and Analysis of Pneumatic Bag Air Jack View project

All content following this page was uploaded by Timur Choban Khidir on 16 February 2019.

The user has requested enhancement of the downloaded file.

International Journal of All Research Education and Scientific Methods (IJARESM)
ISSN: 2455-6211, Volume 5, Issue 4, April 2017, Impact Factor: 2.287

Design and Analysis of Bushed Pin Flexible

Coupling
Timur Choban Khidir

Kirkuk University / College of Engineering - Mechanical Dept.

ABSTRACT

In this research, Design of bushed pin flexible coupling by using the standard equation for design and
applying finite amount of torque for testing purposes to find the main deformation in the couplings thus
trying to improve the design for maximizing the bearing effect for the coupling body and that’s by using
the Solidworks simulation in order to visualize the failure spots on the body. For extra testing we applied
a maximum torque with both bushed rubber and brass, single bush (Brass, Rubber, and Aluminum) and
a solid pin for comparing the results to find the optimum design.

Keywords: Design, Solidworks, Flexible coupling, Rubber and brass bushed, single bush.

I. INTRODUCTION

Bush pin type flange coupling is used to connect of shafts which having a small parallel misalignment, angular
misalignment or axial misalignment. This is a modification of the protected type flange coupling which has pins
(covered by rubber or leather bushes) and it works with coupling bolts. Generally it is used to assemble electric
motors and machines. [1].

In the engines there is a cylindrical flange coupling to union assembled parts. The sensitive piece is a flange to
the parameters like moment, torque, etc. Normally the coupling problems treated as a beam theory. As we know
in mechanical engineering the coupling is used for connection of two shafts to transmit the power. In gear unit
applications the rigid coupling is designed especially for this purpose. [2].

The parameters that effect to the flange and nut-bolts deformation are force and contact stiffness factor. To
study effect of parameters like normal stiffness, the pretension force and friction coefficient under external loads
the simulations of model bolted joint were carried out, ANSYS 14 software used for this simulation. To obtain
accurate results we need a predefined process in this program. In flanged and nut-bolted jointed we can see the
force and stress have direct proportional relation. [3].

In this study, the flanged join is modeled and simulated by using Solidwork v. 2016 .the finite element analysis
procedure required in Solidwork simulation is presented as a predefined process to obtain accurate results.

For the first procedure the coupling is designed as a solution of the given example which finds the dimensions
for the main coupling body and its parts, the simulation is applied on the designed coupling by using Solidwork
model designer and solidwork Simulation add-on for better results on the main stress and deformation areas that
obtained from main acting forces, as a results from the solution of the problem.

The procedure is also aims improving the coupling performance and reducing the stress by applying different
bushes with different materials, for this study only (Rubber, Brass, Aluminum and solid pin alone) is used for
the test.

38
International Journal of All Research Education and Scientific Methods (IJARESM)
ISSN: 2455-6211, Volume 5, Issue 4, April 2017, Impact Factor: 2.287

II. METHODOLOGY:

A. CAD-Models

Fig. 1: Front view of CAD model of Fig. 2: Isometric view of CAD model
bushed pin flexible coupling of bushed pin flexible coupling

The solid model of bearing component is created in SOLIDWORKS V. 2016 software.

B. Analytical Design of Bushed pin flexible coupling

To design a bushed-pin type flexible coupling for alloy steel shaft transmitting 40 Kw at 1000 r.p.m. The
bearing pressure in the rubber bush and allowable shear stress in the pins are to be 0.45 N/mm 2, 25 Mpa and the
Diameter of shaft is 50 mm. [4]. To calculate different Stresses in it we will follow:

Given data,

P = 40× 103 W; N = 1000 r.p.m.; d = 50 mm

The torque transmitted by the shaft,
T = (p×60)/ (2πN) = (40×1000×60)/ (2π×1000) = 382.16×103 N.mm
Considering the shaft in shearing
π
T = 16 × τs × d3
π
382.16×103 = 16 × τs × 503
τs = 15.57 MPa (shear stress induced in shaft)

Design for hub

Outer diameter of the hub (D) = 2d = 100 mm

Length of hub (L) = 1.5 d = 75 mm
Shear stress induced in hub by considering it as hollow shaft.
π D4 − d4
T = 16 × τc D
π 100 4 − 50 4
382.16×103 = 16 × τc 100
τc = 2.0797 Mpa

Design for key

Width of key (w) = 16 mm

Thickness of key (t) = 10 mm
Length of key (L) = 1.5 d = 75 mm
Considering the key in shearing
d
T = L× w× τk × 2
50
382.16×10 3 = 75× 16× τk × 2
τk = 12.738 MPa

39
International Journal of All Research Education and Scientific Methods (IJARESM)
ISSN: 2455-6211, Volume 5, Issue 4, April 2017, Impact Factor: 2.287

Considering the key in crushing

t d
T = L× 2 × σck × 2
10 50
382.16×10 3 = 75× 2
× σck × 2
σck = 40.763 MPa

Design for flange

Thickness of flange (t f ) = 0.5d = 25 mm Shear stress in flange

π D2
T= 2
× τc × t f
π 100 2
382.16 × 103 = × τc × 25
2
τc = 0.97 MPa

Design for bolt

0.5 d
d1 = Nominal diameter of bolts = = 10.2 mm
n
In order to allow for the bending stress induced due to the compressibility of the rubber bush, the diameter of the
pin (d1 ) may be taken as 20 mm.
d = diameter of the shaft = 50 mm
Number of pins (n) = 6

The length of the pin of least diameter d1 = 20 mm is threaded and secured in the right hand coupling half by a
standard nut and washer. The enlarged portion of the pin which is in the left hand coupling half is made of 24
mm diameter. On the enlarged portion, a brass bush of thickness 2 mm is pressed. A brass bush carries a rubber
bush. Assume the thickness of rubber bush as 6 mm. Overall diameter (d2 ) of rubber bush,
d2 = 24 + 2×2 + 2×6 = 40 mm
Diameter of the pitch circle of the pins (D1 ) = 2 d + d2 + 2× n = 152 mm
Outside diameter of flange (D2 ) = 4d = 4×50 = 200 mm
W = pb × d2 × l, where (l) is length of the bush in the flange
W = 0.45 × 40 × l =18 l N
T = W× n× D1/2
382.16×103 = 18 l×6×152/2
l = 46.5 mm say 50 mm
W =18l = 900 N
Direct stress due to pure torsion in the coupling halves,
W 900
τ = π 2 = π 2 = 2.86 N/mm2
(d 1 ) (20)
4 4
Since the induced shear stress in the shaft is less than 25 MPa therefore the design is safe.

Meshing of bushed pin flexible coupling

In this work, SOLIDWORK SIMULATION is used for a meshing of bushed pin flexible coupling. It creates
sufficient smooth meshing as shown in figures below.

Fig. 3: Meshing of hub Fig. 4: Meshing of shaft

40
International Journal of All Research Education and Scientific Methods (IJARESM)
ISSN: 2455-6211, Volume 5, Issue 4, April 2017, Impact Factor: 2.287

The flange coupling body is made of Gray Cast iron C.(A48) with maximum shear and tensile strength 50000
N/mm2 , 151.658N/mm2 respectively the two part are connected with pin bushed bolts and fixed on the shaft
with key .

The shaft used on the test is made of alloy steel type (SS) with max tensile stress of 723.8 N/mm2 is connected
with the coupling by using gib head key.

Fig. 5: Meshing of Nut-Pin- Bushed assembly Fig. 6: Meshing of keys

The assembly of Nut-Pin contains two bushed where made out of Brass and Rubber with thickness of 2 mm and
6 mm consequently which absorbs the main share force acting on the pin neck, and pin itself is made of steel
which can withstand a high shear stress.

The used Gib Head Key is rectangular in cross section having a head at the large end. The head makes it easier
to remove the key from the hub and shaft. The slot for gib head key must have an open end to permit assembly.
For this reason it is placed at the end of a shaft.

Fig. 7: Meshing of bushed pin flexible coupling

C. Boundary condition

A fix support is used to fix a flange from one end.

41
International Journal of All Research Education and Scientific Methods (IJARESM)
ISSN: 2455-6211, Volume 5, Issue 4, April 2017, Impact Factor: 2.287

Fig. 8: Fixed point

D. Analysis:

Test of bushed pin flexible coupling (Both Brass and Rubber bushed).
Test by applying torque at (T = 382.16 N.m obtained from the calculation).

Fig. 9: Equivalent stress of bushed Fig. 10: Total deformation of bushed

pin flexible coupling pin flexible coupling

E. Further Analysis test

Failure test by applying high torque at (T = 1000 N.m)

Fig. 11: Equivalent stress of bushed Fig. 12: Total deformation of bushed
pin flexible coupling pin flexible coupling

42
International Journal of All Research Education and Scientific Methods (IJARESM)
ISSN: 2455-6211, Volume 5, Issue 4, April 2017, Impact Factor: 2.287

Replacing Both Brass and Rubber bushed with

 Only Brass bush with thickness of 8 mm shown in Fig.13

 Only Rubber bush with thickness of 8 mm shown in Fig.14
 Using Aluminum bush with thickness of 8 mm Fig.15
 Solid pin attached to the pin hole shown in Fig.16

Equivalent stress Total deformation

Fig. 13: Brass Bush on high Torque test (T = 1000 N.m)

Equivalent stress Total deformation

Fig. 14: Rubber Bush on high Torque test (T = 1000 N.m)

Equivalent stress Total deformation

Fig. 15: Aluminum Bush on high Torque test (T = 1000 N.m)

43
 International Journal of All Research Education and Scientific Methods (IJARESM)
ISSN: 2455-6211, Volume 5, Issue 4, April 2017, Impact Factor: 2.287

Equivalent stress Total deformation

Fig. 16: Solid Bolt on high Torque test (T = 1000 N.m)

IV. Results and Discussion

Further test applied on the couplings by accessing torque applied on the free end, the material limit is showing
the optimum results on the failure possibilities when change of the bush types or removing it, thus to find the
main deformation that occurs in the main coupling body that happens when using different bush like Brass,
Rubber and Aluminum or removing it completely. Brass bush shows that the both sides of the coupling deforms
with small amount of change due to twisting, while in the Rubber bush the deformation is less and the torque
loss is high as acts like dumper and spring which causes vibrations, while the Aluminum do not shows any
difference compared to the brass as it also causes much deformation and stress for the coupling, thus the
optimum solution is using both Brass and Rubber together to get the best result.

REFERENCES

[1]. Wikipedia, https://en.wikipedia.org/wiki/Coupling.

[2]. Shivaji G. Chavan, Stress Analysis of Flanged Joint Using Finite Element Method, International Journal of Science
and Research (IJSR) ISSN (Online): 2319-7064 Volume 3 Issue 8, August 2014.
[3]. Swati N. Datey, S.D. Khamankar, Hershel C. Kuttarmare, Finite Element Analysis of Universal Joint of IOSR.
[4]. Machine Design – R.S. Khurmi.

AUTHOR

TIMUR CHOBAN KHIDIR

B.Sc. University of Technology–Baghdad / Mech. Eng. – 2005
MsD. Gazi University (Ankara) / Turkey – 2010
Specialist: Applied mechanic
Lecturer in College of Engineering / Kirkuk University

44

View publication stats