Overhanging Ring Gear Structure for Higher Differential Torque
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Solution Overview
Problem
Existing differential assemblies face challenges in increasing the length of ring gear teeth without expanding the outside diameter, which would increase size, weight, and cost, and require more space in the axle housing.
Innovation Solution
The differential assembly design includes a ring gear with a mounting flange and teeth that overhang the fastener hole, allowing the teeth to extend further towards the axis without increasing the ring gear's outside diameter, facilitated by a configuration where the inner side of the ring gear is closer to the axis than the fastener hole, enabling longer teeth without enlarging the ring gear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the ring gear teeth are extended to increase surface area and torque transmission capacity, then the torque transmission capacity is improved, but the outside diameter of the ring gear increases
Solution Approach 1:
The patent applies dimensionality change by moving the teeth radially inward toward the axis of rotation, utilizing the axial dimension rather than increasing the radial dimension. This allows the teeth to overhang the fastener holes and extend further toward the axis, increasing the effective tooth surface area and torque transmission capacity without increasing the outside diameter of the ring gear.
2Power
If the ring gear outside diameter is increased to accommodate longer teeth, then the torque transmission capacity is improved, but the space required in the axle housing increases
Solution Approach 1:
The invention resolves this contradiction by changing the dimensional approach from radial extension to axial extension. The teeth are configured to overhang the fastener holes, extending radially inward toward the axis while maintaining the same outside diameter. This utilizes the existing axial space within the ring gear structure, allowing increased torque transmission capacity without requiring additional space in the axle housing.
3Area of moving object
If the ring gear teeth are extended radially outward, then the surface area of teeth is improved, but the weight of the ring gear increases
Solution Approach 1:
The patent resolves this contradiction by extending the teeth in the opposite radial direction - inward toward the axis rather than outward. This configuration increases the tooth surface area through the overhang structure while actually reducing the amount of material required compared to outward extension, thereby decreasing the weight of the ring gear while maintaining or improving torque transmission capacity.
Data Source
AI summary
A differential assembly having a case and a ring gear. The ring gear is mounted to the case and may include a mounting flange and a set of teeth. The mounting flange may have a fastener hole. The set of teeth overhangs the fastener hole such that the set of teeth extend further toward the axis than at least a portion of the fastener hole.