Sliding camshaft with improved compressive residual stress

摘要

A sliding camshaft for shifting to a selected one of a plurality of selectable cam lobes includes an inner shaft and an outer shaft. The inner shaft has an external spline. The outer shaft has an inner surface, an outer surface, a coating, and an outer portion. The inner surface is subjectable to wear and is configured with an internal spline for transferring torque from and sliding axially on the external spline of the inner shaft. The outer surface is subjectable to wear and loading and is configured with the plurality of selectable cam lobes. The coating on the inner surface is for wear resistance. The outer portion is case hardened for wear resistance of the outer surface and to create a compressive residual stress in the outer portion for load carrying capability.

主权项

1. An outer shaft having an outer portion, an inner portion, an outer surface formed on the outer portion and subjectable to wear and loading, and an inner surface formed on the inner portion and subjectable to wear and configured with an internal spline for transferring torque from and sliding axially on an externally splined inner shaft, the outer shaft comprising:
a coating on the inner surface for wear resistance; wherein the outer portion is case hardened for wear resistance of the outer surface such that the inner portion is softer than the case hardened outer portion to create a compressive residual stress in the outer portion for load carrying capability.