What Are the Differences Between Internal Five-Star Motors and External Five-Star Motors? When to Use Each Type? Can Both Be Equipped with a Braking System? Additionally, How to Deal with the Impact on Workpieces When the Motor Stops?

The internal five-star motor is also known as the SAI motor. Its pressure and transmission ratio are slightly higher than those of the external five-star motor, and its size is slightly smaller. It can be said to be a modified version of the external five-star motor. Both types of motors can be modularized, and a braking system can be added according to customer requirements.

What Are the Differences Between Internal Five-Star Hydraulic Motors and External Five-Star Hydraulic Motors, and What Do They Refer to Respectively?

The key differences lie in three aspects:

Different oil distribution methods: The internal five-star motor adopts axial oil distribution via an oil distribution plate (as noted by hydraulic motor manufacturers), while the external five-star motor adopts radial oil distribution via an oil distribution shaft.

Different indirect connection methods between connecting rod bearings and crankshafts: The connecting rod bearings of the internal five-star motor act on the crankshaft; in contrast, the connecting rod bearings of the external five-star motor are fixed to the crankshaft by a pipe clamp. When the motor is under load, the connecting rod bearings of the external five-star motor may break away from the crankshaft, causing abnormal wear.

Different pressure-resistant methods for piston cylinders: The piston cylinder of the external five-star motor is the housing itself, meaning the motor housing bears high pressure; whereas the internal five-star motor has a dedicated piston cylinder, and the housing does not bear high pressure.