Differential Ring Gear Welding Layout for Position Accuracy
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Solution Overview
Problem
The existing differential devices face issues with position accuracy of the differential ring gear due to solidification contraction after welding, leading to gear noise and reduced accuracy, especially when the distance between the tooth surface and the fixed portion is long.
Innovation Solution
The differential device incorporates a coupling portion with a plate shape that couples the tooth and fixed portions, featuring a flange portion and restricting surfaces to prevent inclination during solidification contraction, with the welding position located differently from the abutting parts, maintaining position accuracy and reducing gear noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If welding is performed on the abutting portion of the differential ring gear to fix it to the differential case, then the differential ring gear is securely fixed, but the welding portion is pulled towards the differential case side due to solidification contraction, causing the differential ring gear to incline and position accuracy to deteriorate
Solution Approach 1:
The invention divides the differential ring gear into three distinct portions: a tooth portion, a fixed and supported portion, and a coupling portion. By segmenting the structure, the welding is performed on the coupling portion rather than directly on the abutting portion, isolating the welding-induced deformation from the critical meshing area. This segmentation allows the tooth portion to maintain its position accuracy while still achieving secure fixing through the coupling portion.
Solution Approach 2:
The coupling portion acts as an intermediary element between the tooth portion and the fixed and supported portion. It serves as the welding zone that absorbs the solidification contraction effects, preventing these effects from directly impacting the abutting portion and differential ring gear inclination. The coupling portion mediates the mechanical connection while isolating the harmful thermal effects of welding from the precision-critical areas.
2Adaptability or versatility
If the distance in the inner/outer peripheral direction of the differential ring gear is made long due to layout requirements, then the speed change mechanism and differential device can be properly arranged, but the differential ring gear becomes more prone to inclination during welding
Solution Approach 1:
The long-distance structure is segmented into tooth portion, coupling portion, and fixed and supported portion. This segmentation allows the coupling portion to serve as a dedicated welding zone that can accommodate the longer distance without compromising the position accuracy of the tooth portion. The segmentation enables the structure to adapt to layout requirements while maintaining manufacturing precision through proper zone separation.
3Reliability
If the differential ring gear is welded on the outer peripheral side, then the abutting portion receives thrust force and welding portion damage is reduced, but the welding portion is pulled towards the differential case side due to solidification contraction, increasing gear noise
Solution Approach 1:
The differential ring gear is segmented so that the coupling portion serves as the welding zone, separating the welding function from the thrust-bearing function. The abutting portion continues to receive thrust forces reliably, while the coupling portion handles the welding process. This segmentation prevents the welding-induced inclination from affecting the thrust force transmission, thereby reducing gear noise while maintaining welding portion reliability.
Solution Approach 2:
The coupling portion acts as an intermediary that absorbs the welding-induced solidification contraction effects, preventing these effects from transmitting to the abutting portion and causing gear noise. It mediates between the welding process and the thrust force transmission, allowing both functions to operate effectively without interfering with each other.
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
This configuration effectively maintains the position accuracy of the differential ring gear after welding, preventing gear noise and ensuring reliable operation by allowing the flange portion to deform and absorb contraction stress.
Implementation Method 1
the welding portion is pulled towards the differential case side due to solidification contraction after welding is performed
Data Source
AI summary
A differential device includes a differential case (10) that has a flange portion (11) and a differential ring gear (40) that has a tooth portion, a fixed and supported portion (45), and a coupling portion. The differential case (10) has a first abutting surface (10a) and a restricting portion (10b). The differential ring gear (40) has a second abutting surface (40a) and an abutting portion (40b). A welding portion that is formed by welding the flange portion (11) of the differential case (10) and the fixed and supported portion (45) of the differential ring gear (40) is disposed at a position that is different from an abutting part between the first abutting surface (10a) and the second abutting surface (40a) and an abutting part between the restricting portion (10b) and the abutting portion (40b).