Variable-Width Gear Teeth for Load-Dependent Meshing Resistance
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Solution Overview
Problem
Gear transmission devices with non-uniform rotation faces experience increased surface pressure and frictional loss as load varies with rotational angle, leading to operational resistance, wear, and heat generation, while existing solutions either increase size or cost due to design constraints.
Innovation Solution
The gear transmission device features tooth portions with varying widths on the driven gear, allowing for increased contact area under high loads and reduced meshing resistance under low loads, maintaining constant surface pressure through proportional tooth width adjustment, and incorporating a helical pinion gear and face gear configuration for compactness and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the tooth width is increased to withstand maximum load, then the strength and durability are improved, but the size and weight of the gear increase unnecessarily
Solution Approach 1:
The patent applies local quality by varying the tooth width along the circumferential direction of the driven gear. Specifically, the tooth width is set to be larger in regions where large driving loads occur and smaller in regions where small loads occur. This localized adjustment ensures that each tooth portion has the appropriate strength for its specific load condition, avoiding the need to increase the overall gear size and weight to handle peak loads throughout the entire gear.
2Loss of energy
If the pressure angle is reduced to improve efficiency, then the energy loss is reduced, but the manufacturing difficulty and cost increase
Solution Approach 1:
The patent maintains a constant pressure angle throughout the gear transmission, which simplifies manufacturing. Instead of varying the pressure angle to reduce frictional loss, the patent achieves efficiency improvement through local quality variation of tooth width. This approach reduces energy loss by optimizing the contact area between teeth while keeping the pressure angle constant, thereby avoiding increased manufacturing complexity and cost.
3Reliability
If the surface pressure is reduced to prevent wear and heat generation, then the durability is improved, but the gear size increases to maintain adequate contact area
Solution Approach 1:
The patent reduces surface pressure and improves durability through local quality variation of tooth width rather than increasing overall gear volume. By making teeth wider in high-load regions, the contact area is increased locally, which distributes the load more effectively and reduces surface pressure in those critical areas. This localized approach prevents wear and heat generation where they are most likely to occur without unnecessarily increasing the volume of the entire gear.
Data Source
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AI summary
[Solution] A drive gear G2 and a driven gear G1 meshing therewith are provided. The driven gear G1 has a plurality of areas that provide driving loads variable with a rotational angle. Tooth widths of tooth portions 5 included in the plurality of areas are set different from each other.