178
CHAPTER 7
BELT DRIVES, CHAIN DRIVES
AND WIRE ROPE
V-Belt Drives
ͳǤ ܥܦ൑ʹͶǤͲǢܦଶൌͳ͵ǤͻͷǢܦଵൌͷǤʹͷǢ͵ ȏ͹ǦͳʹȐ
ʹǤ CD͹Ǧͳ͵ǣܮ௣ൌ͹ͷ
͵Ǥ ߠଵൌͳͺͲιെሺʹሻݏ݅݊ିଵቀଵଷǤଽହିହǤଶହ
ଶሺଶଶǤ଴ሻቁൌ૚૞ૠǤ૛ι ȏ͹ǦͳͶȐ
ͶǤ ܥܦ൑͸ͲǤͲǢܦଶൌʹ͹Ǥ͹ǢܦଵൌͺǤͶǢͷȏ͹ǦͳʹȐ
ͷǤܥܦൌ૞૞Ǥ૞૜ܑܖȏ͹Ǧͳ͵Ȑ
179
ͳͳǤ ݒ௕ൌܴ
ଵ߱ଵൌ଼Ǥସ୧୬
ଶൈଵଵ଺଴୰ୣ୴
୫୧୬ ൈଶ஠୰ୟୢ
୰ୣ୴ ൈଵ୤୲
ଵଶ୧୬ ൌ૛૞૞૚܎ܜȀܕܑܖ
ͳͺǤ ǣൌͳǤͷǢൌͳǤͷሺʹͷሻൌ͵͹Ǥͷ
 ͹Ǧͳ͵Ȃͷ
 ൌͺ͹ͲȀ͵ͳͲൌʹǤͺͳ
ݒ
௕ൎͶͲͲͲȀǢܦଵൌଵଶሺସ଴଴଴ሻ
గሺ଼଻଴ሻൌͳ͹Ǥͷ͸
180
ͳͻǤ ǣൌͳǤʹǢൌͳǤʹሺͷሻൌ͸ǤͲ՜͵
 ൌͳ͹ͷͲȀ͹ʹǤͷൌʹǤͶͳǢܦଵൎͳʹሺͶͲͲͲሻȀߨሺͳ͹ͷͲሻൌͺǤ͹
ʹͲǤ ǣൌͳǤͶǢൌͳǤͶሺͶͲሻൌͷ͸՜ͷ
 ൌͳͷͲͲȀͷͷͲൌʹǤ͹͵ǢܦଵൎͳʹሺͶͲͲͲሻȀߨሺͳͷͲͲሻൌͳͲǤʹ
ʹͳǤ ǣൌͳǤͶǢൌͳǤͶሺʹͲሻൌʹͺ՜͵
 ൌͳʹͷͲȀ͸ͻͷൌͳǤͺͲǢܦଵൎͳʹሺͶͲͲͲሻȀߨሺͳʹͷͲሻൌͳʹǤʹ
181
ʹʹǤ ǣൌʹǤͲሺǤሻ
 ൌʹǤͲሺͳͲͲሻൌʹͲͲ՜ͷ
 ൌͺ͹ͲȀ͸ʹͷൌͳǤ͵ͻǢܦଵൎͳʹሺͶͲͲͲሻȀߨሺͺ͹Ͳሻൌͳ͹Ǥ͸

182
Roller Chain Drives
ʹ͵Ǥ ǤͳͶͲǣൌͳͶ ͺ
ൗൌͳ͵Ͷ
ൗ
ʹͶǤ Ǥ͸Ͳǣൌ͸ͺ
ൗൌ͵Ͷ
ൗ
ʹͷǤ ൌܹ ൌͳʹͷͲǢൌͳͲܹ ൌͳʹͷͲͲ
ʹͺǤ ȏ͹ǦͳͷȐǣǤ͸ͲǡʹͲǡ͹ͷͲ
 ൌʹͳǤ͸ͻሺሻǢሺሻ
͵ͲǤ ȏ͹ǦͳͶȐǣǤͶͲǡͳʹǡͺ͸Ͳ
͵ͳǤ Ͷǣൌ͵Ǥ͵Ǣൌሺ͵Ǥ͵ሻሺ͵Ǥ͹Ͳ݄݌ሻൌ૚૛Ǥ૛૚ܐܘ
͵ʹǤ ȏ͹Ǧͳ͸ȐǣǤͺͲǡ͵ʹǡͳͳ͸Ͳ
͵͵Ǥ ʹǣൌͳǤ͹ǢൌሺͳǤ͹ሻሺ͸ͷǤͷ͹ሻൌͳͳͳǤͷ
͵ͶǤ Ǥ͸ͲǢܰଵൌͳͷǢܰଶൌͷͲǢܥܦ൑͵͸െ͹െͳͻ
͵Ͷ
͵ͷǤ ܮ௖ൌͳʹͺǢܥܦ͹െͳͻ
ଵ
͵͸Ǥ ǤͶͲǣܰଵൌͳͳǢܰଶൌͶͷǢܥ ൑ʹͶ
ͳʹ
͵͹Ǥ ܥܦൌଵ
ସቆͳʹͶെସହାଵଵ
ଶ൅ටቀͳʹͶെସହାଵଵ
ଶቁଶെ଼ሺସହିଵଵሻమ
ସగమቇൌͶ͹Ǥ͸ͻ
͵ͺǤ ǣʹͷǡ݊ଵൌ͵ͳͲǢ݊ଶൌͳ͸ͲǢൌ͵ͳͲȀͳ͸ͲൌͳǤͻͶ
 ൌͳǤͷǢൌͳǤͷሺʹͷ݄݌ሻൌ͵͹Ǥͷ
184
͵ͺǦͶʹ
Ǥ͹Ǧͷ
͵ͺǤ

185

CHAIN DRIVE DESIGN
Application Heavy conveyor driven by a gasoline engine
Example Problem 7-5
Power input: 15 hp
Service factor: 1.4 Table 7-17
Input speed: 900 rpm
Nunber of teeth-Driver sprocket: 17
Computed no. of teeth-Driven sprocket: 65.11
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
Computed nominal chain length: 122.5 pitches
Enter: Specified no. of pitches: 122 pitches Even number recommended
Actual chain length: 91.50 in
Computed actual center distance: 39.766 pitches
Actual center distance: 29.825 in
Angle of wrap-Driver sprocket: 157.9 degrees Should be greater than 120 degrees
Angle of wrap-Driven sprocket: 202.1 degrees
Initial Input Data:
Computed Data:
186

CHAIN DRIVE DESIGN
Application: Hammer mill driven by an electric motor
Problem 7-38
Power input: 25 hp
Service factor: 1.5 Table 7-17
Input speed: 310 rpm
Nunber of teeth-Driver sprocket: 15
Computed no. of teeth-Driven sprocket: 29.06
Enter: Chosen number of teeth: 29 Check availability from vendor
Actual output speed: 160.3 rpm
Enter: Nominal center distance: 40 pitches 30 to 50 pitches recommended
Computed nominal chain length: 102.1 pitches
Enter: Specified no. of pitches: 102 pitches Even number recommended
Actual chain length: 102.00 in
Computed actual center distance: 39.938 pitches
Actual center distance: 39.938 in
Angle of wrap-Driver sprocket: 173.6 degrees Should be greater than 120 degrees
Angle of wrap-Driven sprocket: 186.4 degrees
Initial Input Data:
Computed Data:
187

CHAIN DRIVE DESIGN
Application Agitator driven by a gasoline engine
Problem 7-39
Power input: 5hp
Service factor: 1.0 Table 7-17
Input speed: 750 rpm
Nunber of teeth-Driver sprocket: 16
Computed no. of teeth-Driven sprocket: 36.92
Enter: Chosen number of teeth: 37 Check availability from vendor
Actual output speed: 324.3 rpm
Enter: Nominal center distance: 32 pitches 30 to 50 pitches recommended
Computed nominal chain length: 90.8 pitches
Enter: Specified no. of pitches: 90 pitches Even number recommended
Actual chain length: 45.00 in
Computed actual center distance: 31.573 pitches
Actual center distance: 15.787 in
Angle of wrap-Driver sprocket: 167.9 degrees Should be greater than 120 degrees
Angle of wrap-Driven sprocket: 192.1 degrees
Initial Input Data:
Computed Data:
188

CHAIN DRIVE DESIGN
Application: Heavy conveyor driven by a 6-cylinder Engine
Problem 7-40
Power input: 40 hp
Service factor: 1.4 Table 7-17
Input speed: 500 rpm
Nunber of teeth-Driver sprocket: 14
Computed no. of teeth-Driven sprocket: 28.00
Enter: Chosen number of teeth: 28 Check availability from vendor
Actual output speed: 250.0 rpm
Enter: Nominal center distance: 36 pitches 30 to 50 pitches recommended
Computed nominal chain length: 93.1 pitches
Enter: Specified no. of pitches: 94 pitches Even number recommended
Actual chain length: 94.00 in
Computed actual center distance: 36.432 pitches
Actual center distance: 36.432 in
Angle of wrap-Driver sprocket: 173.0 degrees Should be greater than 120 degrees
Angle of wrap-Driven sprocket: 187.0 degrees
Initial Input Data:
Computed Data:
189

CHAIN DRIVE DESIGN
Application: Centrifugal pump driven by a steam turbine
Problem 7-41
Power input: 20 hp
Service factor: 1.0 Table 7-17
Input speed: 2200 rpm
Nunber of teeth-Driver sprocket: 25
Computed no. of teeth-Driven sprocket: 70.97
Enter: Chosen number of teeth: 71 Check availability from vendor
Actual output speed: 774.6 rpm
Enter: Nominal center distance: 30 pitches 30 to 50 pitches recommended
Computed nominal chain length: 109.8 pitches
Enter: Specified no. of pitches: 110 pitches Even number recommended
Actual chain length: 55.00 in
Computed actual center distance: 30.110 pitches
Actual center distance: 15.055 in
Angle of wrap-Driver sprocket: 151.9 degrees Should be greater than 120 degrees
Angle of wrap-Driven sprocket: 208.1 degrees
Initial Input Data:
Computed Data:
190
͵ͺǦͶʹǤ
CHAIN DRIVE DESIGN
Application: Rock crusher driven by a hydraulic drive
Problem 7-42
Power input: 100 hp
Service factor: 1.4 Table 7-17
Input speed: 625 rpm
Nunber of teeth-Driver sprocket: 21
Computed no. of teeth-Driven sprocket: 58.33
Enter: Chosen number of teeth: 58 Check availability from vendor
Actual output speed: 226.3 rpm
Angle of wrap-Driven sprocket: 197.0 degrees
Initial Input Data:
Computed Data:
191
Synchronous Belt Drives
͹Ǧʹ͹͹Ǧʹͺ
ǤǡǤͶ͵
ͶͶǤ
͹Ǧ͵͹ǦͶǦ
Ǥ
Ͷ͵ ǣαn1αͺͲͲǢαn2α͸ͲͲǢͳͶͶͲǦͺ
 ȋȌ
 ȋȌǡvbǡ
 αnͳȀnʹǣαͺͲͲȀ͸ͲͲαͳǤ͵͵͵Ǣ͹Ǧ͹
Example:͹Ǧ͹ǣȂʹͶǢȂ͵ʹǢCDαʹ͵Ǥͻ͵

ͶͶ ǣαn1αͳʹͲͲǢαn2α͸ͲͲǢͳͺͲͲǦͺǦ͵Ͳ
 αͳʹͲͲȀ͸ͲͲαʹǤͲͲͲǢ͹Ǧ͹
 ȋȌ
vb=(D1/2)(nͳȌαȋʹǤʹͲ͸ȀʹȌȋͳʹͲͲȀȌȋʹSȀȌȋͳȀͳʹȌα͸ͻ͵ǤͲȀ
Sprocket
sets
CD
(in)
D1(in)D2(in) Belt
speed,vb
(ft/min)
BushingDmin
(in)
Dmax
(in)
 ʹʹǣ
ͶͶ ͵ͲǤʹʹ ʹǤʹͲ͸ ͶǤͳͳͳ ͸ͻ͵ǤͲ ͳͳͲͺ
ʹͲͳʹ ͲǤͷͲͲ
ͲǤͷͲͲ ͲǤͺ͹ͷ
ͳǤͺ͹ͷ
 ʹͶǣ
Ͷͺ ʹͻǤ͹Ͷ ʹǤͶͲ͸ ͶǤͺͲʹ ͹ͷͷǤͻ ͳͳͲͺ
ʹͲͳʹ ͲǤͷͲͲ
ͲǤͷͲͲ ͲǤͺ͹ͷ
ͳǤͺ͹ͷ
 ͵͸ǣ
͹ʹ ʹ͸Ǥͺ͹ ͵Ǥ͸Ͳͻ ͹Ǥʹͳͺ ͳͳ͵͵Ǥͺ ͳ͸ͳͲ
ʹͷͳ͹ ͲǤͷͲͲ
ͲǤͷͲͲ ͳǤͷͲͲ
ʹǤʹͷͲ