Gear Drive Device With Biasing Member And Partially Removed Teeth
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Solution Overview
Problem
In gear drive devices, the inter-axial distance between paired gears must be the sum of their pitch diameters, but tolerance variations can cause interference, preventing smooth mesh and torque transmission when the distance is decreased.
Innovation Solution
A gear drive device with a biasing member, such as a torsion spring, that brings the gears into contact at specific tooth surfaces, and partially removes non-contacting tooth surfaces on at least one gear to maintain torque transmission and prevent interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the inter-axial distance is set to the sum of pitch diameters, then smooth gear mesh is achieved, but interference between teeth occurs when tolerance is at its worst
Solution Approach 1:
The harmful portion of the tooth (non-contacting tooth surface) is selectively removed through partial cutting. This extraction eliminates the source of interference while preserving the functional contacting surfaces, allowing the gear to operate reliably even at reduced inter-axial distances.
Solution Approach 2:
The tooth structure is modified locally rather than uniformly. The non-contacting portions are removed while the contacting tooth surfaces are preserved. This localized modification addresses the interference problem without compromising the overall gear strength or meshing quality.
2Object-affected harmful factors
If the inter-axial distance is increased to prevent interference, then tooth interference is eliminated, but the gears do not come into contact on an involute curve
Solution Approach 1:
By removing the non-contacting tooth surfaces, the effective tooth profile is modified to ensure contact occurs only on the involute curve portion. This extraction of harmful material allows the gear to function properly at the optimal inter-axial distance without requiring increased spacing.
3Object-affected harmful factors
If the non-contacting tooth surface is partially removed, then interference is prevented, but gear strength may be compromised
Solution Approach 1:
The tooth is modified locally by removing only the non-contacting portions that cause interference. The contacting surfaces and critical load-bearing regions are preserved intact. This selective local modification prevents interference while maintaining sufficient gear strength for torque transmission.
Solution Approach 2:
Instead of removing entire teeth or excessive material, only the specific non-contacting portions are partially removed. This partial action is sufficient to eliminate interference while conserving enough material to maintain gear strength.
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 ensures smooth gear mesh and torque transmission even when the inter-axial distance is reduced, eliminating the risk of interference and maintaining gear strength.
Implementation Method 1
a biasing member that applies rotational torque in one direction to the first gear or the second gear
Data Source
AI summary
A gear drive device includes a first gear, a second gear that meshes with the first gear to allow torque transmission, and a biasing member that applies rotational torque in one direction to the first gear or the second gear. The first gear and the second gear are brought into contact at a contacting tooth surface thereof by the biasing member. At least one of the first gear and the second gear includes a non-contacting tooth surface that is on an opposite side of the contacting tooth surface and partially removed.