178
CHAPTER 7
BELT DRIVES, CHAIN DRIVES
AND WIRE ROPE
V-Belt Drives
CD
182
Roller Chain Drives
183
185
CHAIN DRIVE DESIGN Application Heavy conveyor driven by a gasoline engine
Example Problem 7-5
Power input: 15 hp
Design speed ratio: 3.83
Number of strands: 1 1 2 3 4
Enter: Chosen number of teeth: 65 Check availability from vendor
Actual output speed: 235.4 rpm
Enter: Nominal center distance: 40 pitches 30 to 50 pitches recommended
Center Distance, Chain Length and Angle of Wrap:
Initial Input Data:
Computed Data:
Design Decisions–Chain Type and Teeth Numbers:
Computed Data:
186
CHAIN DRIVE DESIGN Application: Hammer mill driven by an electric motor
Problem 7-38
Power input: 25 hp
Design speed ratio: 1.94
Number of strands: 3 1 2 3 4
Actual output speed: 160.3 rpm
Enter: Nominal center distance: 40 pitches 30 to 50 pitches recommended
Center Distance, Chain Length and Angle of Wrap:
Initial Input Data:
Computed Data:
Design Decisions–Chain Type and Teeth Numbers:
Computed Data:
187
CHAIN DRIVE DESIGN Application Agitator driven by a gasoline engine
Problem 7-39
Number of strands: 1 1 2 3 4
Actual output speed: 324.3 rpm
Enter: Nominal center distance: 32 pitches 30 to 50 pitches recommended
Center Distance, Chain Length and Angle of Wrap:
Initial Input Data:
Computed Data:
Design Decisions-Chain Type and Teeth Numbers:
Computed Data:
188
CHAIN DRIVE DESIGN Application: Heavy conveyor driven by a 6-cylinder Engine
Problem 7-40
Power input: 40 hp
Number of strands: 3 1 2 3 4
Enter: Nominal center distance: 36 pitches 30 to 50 pitches recommended
Center Distance, Chain Length and Angle of Wrap:
Initial Input Data:
Computed Data:
Design Decisions–Chain Type and Teeth Numbers:
Computed Data:
189
CHAIN DRIVE DESIGN Application: Centrifugal pump driven by a steam turbine
Problem 7-41
Number of strands: 2 1 2 3 4
Actual output speed: 774.6 rpm
Center Distance, Chain Length and Angle of Wrap:
Initial Input Data:
Computed Data:
Design Decisions-Chain Type and Teeth Numbers:
Computed Data:
190
CHAIN DRIVE DESIGN Application: Rock crusher driven by a hydraulic drive
Problem 7-42
Desired output speed: 225 rpm
Design power: 140 hp
Number of strands: 4 1 2 3 4
Actual output speed: 226.3 rpm
Enter: Nominal center distance: 40 pitches 30 to 50 pitches recommended
Center Distance, Chain Length and Angle of Wrap:
Initial Input Data:
Computed Data:
Design Decisions-Chain Type and Teeth Numbers:
Computed Data:
191
Synchronous Belt Drives
n1n2
CD D1D2vb
192
n1n2
Dmin Dmax
Sprocket
sets
CD
(in)
D1(in) D2(in) Belt
speed, vb
(ft/min)
Bushing Dmin
(in)
Dmax
(in)