Tensile Gear Meshing With Pulling Sliding Friction
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Solution Overview
Problem
Conventional gear transmissions with involute gearing experience high mechanical stress, noise, and wear due to high friction and inadequate lubrication, especially under changing load conditions, which limits their suitability for applications like vehicle transmissions and wind power generators.
Innovation Solution
A gear transmission design featuring a head gear with reduced tooth height and a foot gear with root flank engagement starting at the pitch point, utilizing pulling sliding friction to minimize wear and friction, and potentially made from fiber-reinforced materials for enhanced durability and low maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional involute gearing is used, then torque transmission is achieved, but high friction and wear occur due to unfavorable contact pressure conditions
Solution Approach 1:
The patent inverts the conventional tooth engagement approach by using a crown gear with teeth extending beyond the pitch circle that engage with a pinion. This inversion creates favorable contact pressure conditions where the contact point moves from the tooth tip toward the tooth root, ensuring continuous lubrication film and reducing friction and wear compared to conventional involute gearing.
Solution Approach 2:
The patent changes the geometric parameters of gear engagement by positioning the contact point outside the pitch circle and allowing it to move toward the tooth root during engagement. This parameter change creates optimal contact pressure distribution and ensures continuous lubrication, thereby reducing friction and wear while maintaining torque transmission capability.
2Strength
If steel gears are used for high mechanical stress applications, then durability is improved, but weight and complexity increase
Solution Approach 1:
The patent employs fiber-reinforced plastic materials (such as glass fiber or carbon fiber reinforced plastics) for the crown gear and pinion, creating a composite material solution that provides high mechanical stress resistance while significantly reducing weight compared to conventional steel gears. The fiber reinforcement direction is optimized to withstand the specific stress patterns in the tooth engagement zone.
3Adaptability or versatility
If frequent direction changes and load changes occur, then adaptability is improved, but mechanical stress and noise increase
Solution Approach 1:
The patent designs the tooth flanks with specific curvature radii that dynamically adapt to changing load conditions and direction changes. The crown gear tooth flanks are curved to guide the contact point smoothly during engagement, reducing impact forces and mechanical stress during frequent direction and load changes, thereby enabling high adaptability with reduced noise and stress.
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
The design achieves low-friction, quiet, and wear-resistant tooth meshing, suitable for high-load applications with reduced maintenance needs, and can be used in both directions of rotation, improving torque transmission efficiency and extending component lifespan.
Implementation Method 1
a first tooth engagement of the tooth tip flanks of the peripheral teeth of the first driving gear with the tooth root flanks of the peripheral teeth of the second driven gear paired with it occurs at the earliest at the pitch point during rolling along the meshing line, so that the gear transmission forms a tensile toothing with exclusively pulling sliding friction during operation
Data Source
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AI summary
The invention relates to a gear transmission (20) wherein at least a first, driving gear (21) and at least a second, driven gear (31) are meshed together and their toothing comprises interlocking circumferential teeth, wherein the rolling engagement of the two interlocking gears (21, 31) takes place along a line of engagement.The at least one first, driving gear (21) is designed as a head gear (Za) with circumferential teeth whose tooth height (ha) corresponds to a simple module (m) of their tooth tip flanks (26) including a tip clearance (cb), and the at least one second, driven gear (31) is designed as a foot gear (Zb) with circumferential teeth whose tooth height (hb) corresponds to a simple module (m) of their tooth root flanks (36) including a tip clearance (ca), and wherein a first tooth engagement of the tooth tip flanks (26) of the circumferential teeth of the first, driving gear (21) with the tooth root flanks (36) of the circumferential teeth of the paired second, driven gear (31) occurs at the earliest at the pitch point (C) when rolling along the line of engagement (C,E), so that the gear drive (20) in operation has a tensile gear with exclusively tensile sliding friction (39) trains.