Stepped Shaft Sliding Member Axial Positioning

A sliding member is introduced as an intermediary component between the first sun gear and the second sun gear. This sliding member has a sliding surface that contacts the end surface of the first sun gear, providing reliable axial positioning without requiring a large dimensional difference between the male spline part and first sun gear. The sliding member acts as a mediator that transfers and stabilizes the axial position while allowing the gear dimensions to be optimized for higher speed reduction ratios.

The axial load bearing function is extracted from the output shaft bearing system and transferred to the sliding member. The sliding member, which is already present for positioning purposes, is given the additional function of bearing axial loads through its sliding surface contact with the first sun gear. This eliminates the need for expensive taper roller bearings, allowing the use of simpler and more cost-effective bearing solutions while maintaining axial load bearing capability.

The sliding member serves as an intermediary that contacts the first sun gear for axial positioning instead of allowing direct contact between the first sun gear and the output shaft. This intermediary arrangement protects the bearing from excessive axial loads while maintaining positioning functionality. The sliding member absorbs and manages the axial load forces, preventing them from being transmitted to the bearing system.

The sliding member is designed to perform multiple functions: it provides axial positioning of the first sun gear, bears axial loads, and creates a stable sliding surface through its contact with both the first and second sun gears. By making the sliding member multi-functional, the patent achieves improved positioning stability without significantly increasing device complexity, as the same component serves multiple purposes rather than requiring additional specialized parts.