Page 54 - Mechanical Engineer's Data Handbook

STRENGTHS OF MATERIALS 43

Sleeve shaji coupling

Symbols used :
D = shaft diameter
Do = sleeve outer diameter
T= torque transmitted
7 =allowable shear stress
Friction lining N=speed
P = power
b=key width
L = key length

Solid bolted shaft coupling
Torque capacity of shaft T= nD3r f 16
Symbols used:
DbLt
D =shaft diameter Torque capacity of key T=-
D,=pitch circle diameter of bolts 2
D, = bolt diameter Power capacity of shaft P=n2ND3rJ8
n = number of bolts Torque capacity of sleeve T= nt(D: - D4)/16D,
b = width of key (allowance to be made for keyway)
L = length of key and hub For equal strength of sleeve and shaft Do= 1.220.
P= power transmitted
N = shaft speed Pinned sleeve shaft coupling
FS=factor of safety
7,, =shear yield stress Symbols used:
D = shaft diameter
d = pin diameter
Torque capacity of pin T= nd2Drf4

I -i-d

I .6.5 Bonded rubber shaft coupling
Power capacity P = n2NnD,D~zYJ4 FS
Key FS=nDNbLr,JP Symbols used:
Shaft FS = n2ND3ryJ8P 0 =angle of twist
If bolts and shaft have same material and FS, then: T= torque
Bolt diameter D, = Jm G =shear modulus
s = spring constant = TJ9