A Variable Speed Pulley (also called a Variable Pitch Pulley or Adjustable Pulley) is a mechanical device used to change the rotational speed (RPM) of a driven shaft without changing the motor speed. It achieves this by altering the effective diameter of the pulley, thereby changing the gear ratio between the driving and driven pulleys.

Key Benefits

• Allows speed adjustment without stopping the motor
• Simple and cost-effective method of speed control
• No electronics needed
• Can help optimize performance for varying loads or material types

How It Works

• The pulley consists of two conical sheaves (halves) that move closer together or farther apart.
• As the sheaves move, the belt rides higher or lower on the pulley, changing the pitch diameter.
• This causes the driven equipment to speed up or slow down depending on the pulley’s adjustment.