Project Members :

M.Nishanth (21008114072)Rahul S. Nair (21008114085)B.Shivakumar (21008114100)Waseem G.M. (21008114132)

Project Guide :

C.Karthikeyan. M.E, PhDAssistant Professor,Department of Mechanical Engineering,Panimalar Engineering College

OBJECTIVE

• The objective of this project is to design and fabricate a Bushed-pin type flexible coupling.

• Its function is to transmit power between shafts that are partially misaligned and it also absorbs shock loads.

• It employs rubber bushes fitted over pins that transmit torque by means of shear resistance.

• Design will be carried out by choosing a prime mover having an output of 5000 W and a speed of 750 rpm.

PHOTOGRAPHIC VIEWS OF THE COUPLING

AUTOCAD DIAGRAM OF THE COUPLING

LIST OF COMPONENTS USED

• INPUT FLANGE : It is keyed to the input shaft coming from the prime mover and transmits power to the pins through the rubber bush.

• OUTPUT FLANGE : It obtains power from the pins by means of shear resistance, is keyed to the output shaft.

• PINS : The pins here are nothing but unthreaded bolts. They connect the two flanges and also maintain a clearance between the two shafts for angular misalignment.

• RUBBER BUSHES : These rubber bushes are provided to absorb shock loads, torsional vibrations and angular misalignments. They are provided with brass linings to reduce wear.

Design of the Bushed-pin Coupling

Materials chosen to carry out design of coupling :

• SHAFTS : Since shafts are subjected to torsional shear stresses, “PLAIN CARBON STEEL” is chosen on strength basis. Grade : 40C8 , Yield stress : 380 N/mm2 , FOS : 2

• KEYS : Subject to shear and compressive stresses.• PINS : Subject to shear and bending stresses. Grade : 30C8 , Yield stress : 400 N/mm2 , FOS : 2

• FLANGE : Manufactured by casting due to their complex shape. Grade : GCI FG200 , Ultimate stress : 200 N/mm2, FOS : 6

• The design calculations were carried out such that the “Shaft governed the design”

• Using Initially assumed values of Power and prime mover speed, the shaft diameter was obtained as 16mm.

• Now by using data from PSG Data book (page 7.108, table 2) the various parameters were obtained.

• Further , actual stress values were calculated for the keys, pins, bushes and flanges. The design was calculated to be lesser than the permissible values of design, hence the design is “safe”.

DESIGN SYNOPSIS

DESIGN OUTPUT DIAGRAM DRAWN USING AUTOCAD

DESIGN OUTPUT PARAMETERS

• SHAFT DIAMETER : 16mm • OUTER FLANGE DIAMETER : 100 mm• HUB DIAMETER : 30mm• PCD of PINS : 63mm• LENGTH OF HUB : 30mm• PIN DIAMETER : 10mm• LENGTH OF BUSH : 20mm• PROTECTIVE LAYER : 12mm THICKNESS• NUMBER OF PINS : 4• DIAMETER OF BUSH : 22mm• CLEARANCE : 2mm

ADVANTAGES

• It can tolerate 0.5mm of lateral or axial misalignment and 1.5 degrees of angular misalignment.

• Prevents transmission of shock from one shaft to the other and absorbs vibrations.

• It can be used for transmitting high torques.

• It is simple in construction and easy to assemble and dismantle.

• It is easy to design and manufacture the coupling.

• For the same size of shafts, flexible bush coupling has larger number of bolts or larger pitch circle diameter than rigid type coupling. This reduces the force acting on the pins and lowers bearing pressure on the rubber bush.

DISADVANTAGES

• The cost of flexible coupling is more than that of rigid coupling due to additional parts.

• It requires more radial space compared with other types of coupling.

• Maximum allowable peripheral speed of the coupling is 30m/s.

THANK YOU