DMS Bushed Pin calculation of strengths..

design of machine elements

1. BHARATI VIDYAPEETH COLLEGE OF ENGINEERING, NAVI MUMBAI DEPARTMENT OF MECHANICAL ENGINEERING DMS 2022-23 Presented By: 1) Sumit Maji(4744) 2) Anup Maurya(4745) 3) Tanmay Mhatre(4749) 4) Sumit Mishra (4751)                                                                                     Prof: GANESH KATKE Bushed Pin Flexible Coupling

2. Content Sr No. Topic Pg No. 1 Coupling 1 2 Types of Shaft Coupling 2-3 3 Bushed Pin type Flange Coupling 4 4 CAD Model 5 5 Analytical design of bushed pin flange coupling 6-7 6 Design of Hub 8 7 Design for Key 9 8 Design for Flange 10 9 Design for Bolts 11-12 10 Python Coding 13-16 11 Output 17-19

3. Coupling Coupling s are mechanical elements that ‘couples’ two drive elements(shafts) which enables motion to be transferred from one element to another.

4. Types of Shafts Couplings 1. Rigid Coupling 2. Flexible Coupling Rigid Coupling: It is used to connect two shafts which are perfectly aligned. Types of Rigid Coupling are Sleeve or muff coupling Clamp or split-muff coupling

5. 2.Flexible coupling : It is used to connect two shafts having both lateral and angular misalignment. Types of flexible coupling are Bushed pin type coupling, Universal coupling, Oldham coupling

6. Bushed Pin Type Flange Coupling

7. Analytical Design of Bushed pin flexible coupling It is required to design a bushed pin type. Flexible coupling to connect the output shaft of an electric motor to the shaft of a centrifugal pump. The motor delivers 20KW power at 720 rpm. The starting torque of the motor can be assumed to 150% of the rated torque. Design the coupling and specify the dimensions of its components with suitable material. . To calculate different Stresses in it we will follow:

8. Python Coding # Online Python - IDE, Editor, Compiler, Interpreter import math print("For keys,bolts and shaft, the material selected is C20 mild steel") print("Hence the corresponding tensile strength(TS1)= 110MPa and the shear strength (SS1)= 55MPa") print("For coupling(Hub), the material selected is cast iron GCI15" ) print("Hence the corresponding tensile strength(TS2)= 37.5MPa and the shear strength (SS2)= 18.75MPa") TS1 = 110 TS2 = 37.5 SS1 = 55 SS2 = 18.75 P= int(input("Power(W):")) N=int(input("Driver speed(rpm):")) Ks=float(input("Factor of safety:")) print("Assuming bearing pressure between the bush and the coupling=2MPa ") print("") #shaft diameter print("Step 1: Calculation of shaft diameter") print("") T=(P*60*Ks*1000)/(2* math.pi *N) print( f'Torque T (in Nmm ):{T}') d = math.pow (T*16/( math.pi *SS1), 1/3) print( f'Diameter of shaft in mm:{d}') stdds = 35 print("") # dimension dimension_coupling = (P * Ks * 100)/N print( f'Kilowatt per 100 RPM: { dimension_coupling }') print("") print("Step 2:Dimensions of coupling") print("According tp PSG,corresponding to 100 KW per 100 rpm we choose coupling=6") print("Values corresponding to coupling numer 6 are:") CONTD .

9. print("Diameter of hub(D1)=C=100mm") print("Diameter of bolt circlr (D2)=D=150mm") print("Outer diameter of flange(D3)=B=200mm") print("Length of hub=Length of key=E=L=56mm") print("Overall thickness=G=40mm") print("Thickness of protected flange(H)= tp =15mm") print("Thickness of flange=G-H= tf =25mm") print("Diameter of bush= db =30mm") print("Thickness between two flanges=4mm") print("Diameter of bolt=F=12mm") print("Number of bolts=4") print("") #dimenson of key print("Step 3:Dimension of keys") print("From PSG,for the following diameter d:") print("w=10mm") print("t=8mm") print("") print("Step 4:Checking for strength of coupling") print("A. Considering hub as a hollow shaft") D1=100 SS2ch=(16*T*D1)/( math.pi *((D1**4)-( stdds **4))) print( f'calculated shear strength for hub:{SS2ch}') if(SS2>SS2ch): print("The design is safe") else: print("The design is unsafe") print("") print("B. Considering the flange") tf =25 SS2cf=(T)/( math.pi *D1* tf *0.5*D1) print( f'calculated shear strength for flange:{SS2cf}') if(SS2>SS2cf): print("The design is safe") else: print("The design is unsafe") print("") CONTD .

10. print("Step 5:Checking strength of keys") print("A. Considering shear") l=56 w=10 SS1ck=(T)/(l*w* stdds *0.5) print( f'calculated shear strength for keys:{SS1ck}') if(SS1>SS1ck): print("The design is safe") else: print("The design is unsafe") print("") print("B. Considering crushing") t=8 TS1ck=(T*4)/(l*t* stdds ) print( f'calculated tensile strength for keys:{TS1ck}') if(TS1>TS1ck): print("The design is safe") else: print("The design is unsafe") print("") # print("Step 6: Design of bolts") print("A. Considering shear") db =30 D2=150 n=4 SSb =(T*8)/( math.pi *( db **2)*D2*n) print( f'Shearing strength of bolt:{ SSb }') print("") print("B. Considering bending") print("Ft=(2*T)/(D2)=5305.06 N") G=40 F=12 Ft=5305.06 Mb=(Ft*(t+0.5*(G-0.66*F))*(1/n)) z=( math.pi *( db **3))/32 CONTD .

11. BM = (Mb/z) SS1cb=(0.5*( math.sqrt ((BM**2)+(4* SSb )))) print( f'Shearing strength of bolt due to bending:{SS1cb}') if(SS1>SS1cb): print("The design is safe") else: print("The design is unsafe") print("") # print("Step 7: Checking the crushing strength of bolt") dbush =30 Pbc =(Ft)/( dbush *((G-0.66*F)*(n))) Pba =2 if( Pba > Pbc ): print("The design is safe") else: print("The design is unsafe") print("")

12. Output CONTD.

13. Thank You