BEARING OD SHIM

This shim is a thin metal ring. It goes around the outside of a bearing.

Think of it like a thin metal sleeve or wrapper. You put it on the bearing before you press the bearing into the pump housing. It takes up extra space. It makes the bearing fit tighter .

Shims in vacuum pumps are used for adjustment and alignment. They help keep the right amount of space between moving parts .

Specifically, a bearing OD shim does two main jobs:

1. Adjusts the fit: If the bearing is a little loose inside the housing, the shim fills the gap. The bearing fits tight and does not spin inside the housing.

2. Controls end play: In some pumps, these shims also help set how much the rotor can move back and forth (end clearance) .