Hi-Ratio Compound Pulleys for ¼ and ½ hp. drives provide economy and exceptional efficiency at speed ratios up to 7 to 1. Pulley faces are made of highly durable plastic containing special additives to insure long service life.
The pulley itself is comprised of two parts, either of which can be used independently. These are:
No. HR-2 Variable Speed Pulley Assembly which is needle-bearing mounted on a hardened and ground countershaft. It requires a control of some type for operation.
No. HRB-2 Control Base. On the majority of applications, this base eliminates the necessity for a pivoted motor base to maintain proper belt tension.
Operating Principles
The Hi-Ratio Pulley is needle-bearing mounted on a hardened and ground crankshaft. Speed variation is accomplished by moving the countershaft between the driving and driven sheaves. Movement towards the driver (Fig. 1) reduces the driven speed. Movement away from the driver increases the driven speed
