What Is a GM21VA Rotary Group?

The GM21VA Rotary Group is the main internal rotating assembly of a hydraulic travel motor. It is commonly used in the final drive system of crawler excavators.

These motors are typically part of the **Nabtesco GM series hydraulic motors.

Parts Included in a GM21VA Rotary Group

A typical rotary group contains several components, such as:

• Cylinder block

• Pistons

• Piston shoes

• Retainer plate

• Ball guide

• Drive shaft

• Swash plate

All these parts work together to convert hydraulic pressure into rotational power.