PIC Design - RBC Bearings

E*P*S DRIVER SYSTEM SELECTION PROCEDUREIn order to select the correct drive system for your application, thefollowing procedure is recommended:1. Determine the design horsepower (Dhp).Dhp = rated hp x SFService factors (SF) of 1.5 to 2.0 are recommended forminiature timing belts. In drive systems which require a highdegree of dependability or have high stock loads, higher servicefactors are recommended.2. Belt pitch and pulley selectiona. Using the E*P*S drive belt selection chart, select thepitch belt which has the Dhp capacity at the smaller pulleyspeed.b. The Speed Ratio is determined by dividing the larger speed,pulley pitch diameter or groove number by the lesser speed,pulley pitch diameter or groove number.c. To select the proper pulley, refer to pulley dimensions listedwith corresponding pitch.d. The pitch line velocity of the smaller pulley should notexceed 6500 FPM.PLV = .262 x Pulley PD (in.) x Pulley RPM3. To determine the proper belt length at nominal center distance,use the following formula:L = 2C + (D-d)2 + 1.57 (D + d)4CWhere L = Belt Pitch LengthC = Center DistanceD = Pitch Diameter Large Pulley (inches)d = Pitch Diameter Small Pulley (inches)4. To determine the center distance in inches when belt lengthand pulleys are known.CAPPROX = K + K2 -32 (D-d) 216Where K = 4L - 6.28 (D + d)Other useful formulas:HP =Torque ( in-lbs.) x RPM63025Belt Speed fpm = Pitch Diameter x RPM x .262NOTE:If the number of teeth in mesh on the smaller pulley is lessthan 6, correct the design hp by the following factors:Teeth in Mesh Design HP Multiplication Factor5 1.24 1.53 2.02 Suggest Alternative Drive1 Suggest Alternative DriveL EXACT= 2C Cos ∅ + π (D +d) π ∅ (D -d)+2 180Where ∅ = sin -1( D-d 2C )E*P*S Drive Selection ChartDesign Horsepower Per Inch of Belt Width5-24Phone: 800-243-6125 ■ FAX: 203-758-8271E-Mail: sales@pic-design.comDESIGN®www.pic-design.comInteractive catalog ■ CAD ■ e-commerce