How do i know what size pulley i need for my compressor

Measuring Pulley Outside Diameter

Place your pulley face down on a flat surface, then put your ruler or caliper on top, measure from outside edge to outside edge across the circle of the pulley. Check carefully to make sure you are measuring across the center.

Pulleys of Different or Same Size

If a smaller pulley turns a larger one, the larger one will turn slower, but with more power available at the shaft. If a bigger pulley turns a smaller one, the smaller one will turn much faster than the bigger one but with less power available at the shaft.

Increasing Speed: When the powered pulley is larger than the non-powered pulley then the speed of the non-powered pulley is higher in proportion to the circumferences of the pulleys. … The non-powered pulley will move slower but it will be able to generate twice as much torque.

A larger diameter pulley wheel (aka sheave) is technically more efficient than a smaller diameter pulley. But it’s a trade off: a larger pulley has increased bulk, weight and cost. … This efficiency increases with really big loads (600 lbs+) and larger mechanical advantage, such as 6:1 and 9:1.

A larger pulley turning a smaller pulley results in the smaller one turning faster but with less shaft power. For example, a truck in high gear would have a slower turning engine but faster turning wheels, resulting in a faster truck.

Pulleys and belts have two uses; to increase or reduce speed or torque, or to transfer power from one shaft to another. If the transfer of power is all you need, then two pulleys of the same diameter will do the trick.

Pulleys and Speed

A smaller pulley turning a larger pulley results in the larger one moving more slowly but with more shaft power. … For example, a truck in high gear would have a more slowly turning engine but fast turning wheels, resulting in greater speed of the truck.

Pulleys provide a simple way to transfer power from one shaft to another. By using pulleys with various diameters, you can specify the mechanical advantage and the relative speeds of the shafts. As with other simple machines, pulleys may exhibit a mechanical advantage by trading distance for force.

You could say, in general, that the pulley load reduction is the reciprocal of the number of ropes supporting the load, but few practical pulley systems have more than four ropes. Consequently, the maximum pulley load reduction you can realize is one-quarter the weight of the load.

Increasing the pulley to 3.2 inches also increases the amp draw to 7.8. The motor is now running continuously at its service factor, generating additional heat and shortening the motor’s useful life. Increasing the pulley sizes to 3.45 or 3.55 will leave the motor continually operating in an overloaded mode.

Add half of the diameter of each pulley to twice the shaft-center-to-shaft-center distance. Get the next larger standard size of belt. Install the belt on the pulleys and move the units apart until the belt has a slack of about 1/2 inch.

Find the speed of the driven pulley by solving the pulley speed equation (N1)(D1)=(N2)(D2). D1 is the diameter of the driven pulley, D2 is the diameter of the drive pulley, N1 is the speed of the driven pulley and N2 is the speed of the drive pulley.

According to Ohms Law (I=E/R or Amps=Volts/Ohms) if the voltage in the circuit remains constant and the resistance is increased, the current should decrease. Try adding resistance to the circuit to lower the current output.