Single-Tooth Gear Transmission for Reversible High-Reduction Drive
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gear drives with a drive wheel having a single tooth (Z=1) are not designed for easy reverse rotation, which is essential in applications requiring manual operation during power failures, such as automotive and building technologies.
Innovation Solution
A gear transmission design with a drive wheel having external teeth Z=1 and a counter gear with Z≥1, where the tooth height and root radius factors are optimized to allow easy reverse rotation, ensuring a total overlap greater than 1.3 and compliance with specific root and addendum height factors, enabling reverse rotation independently of the pressure angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If gear drives with Z=1 are designed for high speed reduction ratio, then torque is increased, but reverse rotation capability is lost
Solution Approach 1:
The patent applies parameter changes by optimizing specific geometric parameters of the gear teeth: the addendum height factor haP is set to 0.6-0.8, the root height factor hfP is set to 0.2-0.4, and the root radius factor rfpP is set to 0.1-0.4. These parameter modifications enable the gear drive to achieve both high torque through speed reduction and maintain reverse rotation capability, resolving the technical contradiction between force multiplication and operational reversibility
2Strength
If tooth height is increased for better meshing, then gear strength is improved, but reverse rotation becomes difficult
Solution Approach 1:
The patent resolves this contradiction through precise parameter changes in tooth geometry. The addendum height factor haP is limited to 0.6-0.8 (preventing excessive tooth height that would hinder reverse rotation), while the root height factor hfP is set to 0.2-0.4 and root radius factor rfpP is set to 0.1-0.4 (ensuring adequate strength). This balanced parameter optimization allows the gear to maintain both strength and reversibility
3Force
If pressure angle is increased for higher load capacity, then torque transmission is improved, but reverse rotation capability deteriorates
Solution Approach 1:
The patent addresses this contradiction by optimizing the pressure angle parameter within a specific range and combining it with optimized tooth geometry parameters. The pressure angle is set to provide adequate load capacity while the addendum height factor (0.6-0.8) and root radius factor (0.1-0.4) are adjusted to ensure the tooth profile allows smooth reverse rotation even at higher pressure angles, maintaining both torque transmission and reversibility
Data Source
Figure 1a~1b
Figure 2a~2c
Figure 3a~3b
AI summary
To create a gear transmission with a reduction gear ratio comprising a drive gear with external teeth Z = 1, which is self-locking or reliably reversible from the output side, separate sets of gear parameters are proposed, each in combination with a specific total contact ratio εγ of the drive and mating gears, wherein the total contact ratio εγ is the sum of the profile contact ratio εα and the jump contact ratio εβ of the drive and mating gears. With the invention, the gear transmissions can be designed to be reliably reversible or self-locking, largely independent of the pressure angle.