Rear Wheel Steering Planetary Gear Support Using Universal Pin
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rear wheel steering apparatuses for vehicles face increased costs due to the need for dedicated flat head pins and suffer from frictional issues with synthetic resin locking members that absorb grease and produce heat, deteriorating their function.
Innovation Solution
A rear wheel steering apparatus using a circular columnar pin to support the planetary gear, with a locking member having a concave portion and protruding ridges to reduce contact area and prevent co-rotation, allowing the use of general-purpose pins and synthetic resin locking members, thereby reducing costs and maintaining effective support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dedicated flat head pin is used to support the planetary gear, then the planetary gear can be reliably supported, but the manufacturing cost increases
Solution Approach 1:
The patent replaces the dedicated flat head pin with a general-purpose circular columnar pin that can be used in multiple applications. This pin, combined with a synthetic resin locking member, achieves the same planetary gear support function without requiring a specialized component, thereby reducing manufacturing costs while maintaining reliability
Solution Approach 2:
The patent introduces a synthetic resin locking member as an intermediary component that works together with the general-purpose pin to retain the planetary gear. This locking member, made of grease-resistant synthetic resin, prevents the pin from co-rotating with the planetary gear while allowing smooth rotation, thus achieving reliable support without needing a dedicated flat head pin
2Ease of manufacture
If a synthetic resin locking member with simple disk shape is used, then the manufacturing cost decreases, but frictional heat is produced and the locking member co-rotates with the planetary gear
Solution Approach 1:
The patent modifies the locking member by providing contact portions only at specific locations (radially around the pin) rather than a complete disk shape. This localized contact design reduces the surface area in contact with the planetary gear, preventing grease absorption and co-rotation while maintaining the locking function, thus resolving the contradiction between manufacturing simplicity and functional reliability
3Strength
If the locking member has large contact area with the planetary gear, then the locking function is strong, but grease is absorbed and frictional heat is produced
Solution Approach 1:
The patent designs the locking member with contact portions located only at the radial edges around the pin, creating localized contact points rather than a large continuous contact area. This design maintains sufficient locking strength through concentrated contact while minimizing grease absorption and frictional heat generation by reducing the overall contact surface area with the planetary gear
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively supports the planetary gear, reduces frictional heat, and lowers costs by utilizing general-use pins and easily manufactured synthetic resin locking members, ensuring reliable operation and reduced co-rotation of the locking member.
Implementation Method 1
a rod which is screwed to the nut member and is connected to the second connecting member, and converts the rotational motion of the nut member into the linear motion of the rod
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A rear wheel steering apparatus for a vehicle includes: a housing (1) connected via first and second connecting members to a suspension mechanism supporting rear wheels (RL, RR) of a vehicle; an electric motor (3a) accommodated in the housing; a planetary gear mechanism (30) having a sun gear (31) connected to an output shaft (20) of the electric motor, a ring gear (33) non-rotatably supported inside the housing, a planetary gear (32) meshing with the ring gear and the sun gear, and a carrier connected to the planetary gear, and reducing the output of the electric motor; and a linear motion mechanism (3c) having a nut member (36) connected to the planetary gear mechanism and forming the carrier, and a rod (2) screwed to the nut member and connected to the second connecting member, and converting the rotational motion of the nut member into the linear motion of the rod.