Development of Long-Life Needle Roller and Cage Assembly with Special Specification and Shaft with Unique Heat Treatment

A newly developed roller in the needle roller and cage assembly has a special heat treatment and special surface modifications. A newly developed shaft, where the outer surface acts as the inner raceway for the rollers, also has an unique heat treatment.

The life comparison test results show that the combination of the new rollers and new shaft has an approximately 3.0 times longer life than the conventional product.

In the bench test, the new rollers and new shafts are installed in an actual planetary type transmission of a construction vehicle. The bench test shows 2.9 times longer life. After the bench test, both the new rollers and new shafts show no sign of damage.