E*P*S Driver System Selection Procedure

In order to select the correct drive system for your application, the

following procedure is recommended:

1. Determine the design horsepower (Dhp).

• Dhp = rated Hp X Sf
• Service factors (Sf) of 1.5 to 2.0 are recommended for
• miniature timing belts. In drive systems which require a high
• degree of dependability or have high stock loads, higher service
• factors are recommended.

2. Belt pitch and pulley selection

• a. Using the E*P*S drive belt selection chart, select the pitch
  • belt which has the Dhp capacity at the smaller pulley speed.
• b. The speed ration is determined by dividing the larger speed,
  • pulley pitch diameter or groove number by the lesser speed.
  • c. To select the proper pulley, refer to pulley dimensions
  • listed with corresponding pitch.
• d. The picth line velocity of the smaller pulley should not exceed 6500 rpm
• PLV = .262 x Pulley PD (in.) x Pulley RPM

3. To determine the proper belt length at normal center distance, use

• the following formula:
• 

WHERE: L = Belt pitch length

C = Center Distance

D = Pitch Diameter Large Pull

ey (inches)

d = Pitch Diameter Small Pulley (inches)

4. To determine the center distance in inches when belt length

and pulleys are known.

• 
• Other Useful Formulas:
• 
• Belt Speed fpm = Pitch Diameter x RPM x .262

NOTE: If the number of teeth in mesh on the smaller pulley is less

than 6, correct the design HP by the following factors:

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