Speed Reducer Roller Gap Control for Vibration Reduction
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Solution Overview
Problem
Conventional roller type speed reducers suffer from manufacturing errors leading to varying roller gaps, resulting in inefficient speed transmission, vibration, and reduced lifespan due to excessive surface pressures, as they often fail to maintain roller gaps within an optimal range.
Innovation Solution
The method involves adjusting roller gaps between rollers and internal gear teeth within a range of 0 to 20 µm by measuring the root radius of the internal gear, radius of the rolling bearing, and outer diameter of the rollers, ensuring consistent and stable operation by preventing collisions and excessive surface pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional speed reducers are assembled without controlling the roller gaps, then the assembly process is simple and fast, but the roller gaps vary from one speed reducer to another, causing vibration, torque loss, and reduced efficiency
Solution Approach 1:
The patent applies preliminary action by pre-adjusting the roller gaps to a predetermined value during the assembly process. Specifically, the adjustable mechanism allows the roller gap to be set to a predetermined value before final assembly completion, ensuring consistency across all speed reducers while maintaining a relatively simple assembly process. This resolves the contradiction by implementing precision control without significantly increasing assembly complexity.
2Ease of operation
If the roller gaps are too large, then the assembly is easier with more tolerance, but the rollers collide against the tooth bottoms causing vibration and instability
Solution Approach 1:
The patent applies parameter changes by making the roller gap adjustable rather than fixed. The adjustable mechanism allows the roller gap parameter to be optimized to a specific range that prevents roller collision with tooth bottoms, thereby ensuring operational stability and reliability. This resolves the contradiction by enabling precise parameter control that maintains both assembly ease and operational reliability.
3Manufacturing precision
If the roller gaps are too small, then the speed transmission is more precise, but excessive surface pressures are generated causing premature peeling and reduced lifespan
Solution Approach 1:
The patent applies parameter changes by enabling adjustment of the roller gap to an optimal value that balances speed transmission precision with component lifespan. The adjustable mechanism prevents excessive surface pressures by maintaining the roller gap within an appropriate range, thereby avoiding premature peeling while preserving precise speed transmission. This resolves the contradiction by optimizing the roller gap parameter to simultaneously achieve precision and durability.
4Ease of manufacture
If the roller gaps are not controlled within an optimum range, then the manufacturing process is simpler, but the speed reducer cannot rotate at constant speed and efficiency is reduced
Solution Approach 1:
The patent applies preliminary action by pre-setting the roller gap to a predetermined optimal value during assembly. This ensures that the speed reducer operates at constant speed with high efficiency while maintaining manufacturing simplicity. The adjustable mechanism allows the roller gap to be predetermined and controlled without significantly complicating the manufacturing process, thereby resolving the contradiction between manufacturing simplicity and operational efficiency.
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 adjustment reduces vibration and stabilizes the speed reducer's quality by maintaining optimal roller gaps, ensuring constant speed transmission and minimizing torque loss and premature wear.
Implementation Method 1
rolling bearings press-fitted on the radially outer surfaces of the respective eccentric disks
Implementation Method 2
rollers are received in the respective pockets so as to engage the internal teeth of the internal gear one after another while rolling along the radially outer surfaces of the rolling bearings
Data Source
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AI summary
It is desired to reduce vibration of a speed reducer. The speed reducer includes a fixed internal gear (3), an input shaft (7) coaxial with the internal gear (3), and an eccentric disk (9) provided on the input shaft (7) and rotatable inside the internal gear (3). A cage (14) is provided at an end of an output shaft (12) coaxial with the input shaft (7) so as to be rotatable between the internal gear (3) and the eccentric disk (9). The cage (14) is formed with pockets (18) which are fewer in number than the internal teeth (4) of the internal gear (3). Rollers (19) are received in the respective pockets (18) such that when the input shaft (7) is rotated once, and the eccentric disk (9) is rotated together with the input shaft, each of the rollers (19) is pushed by the rolling bearing (11) fitted on the eccentric disk (9) and circumferentially moves by a distance equal to the width of one internal tooth (4) while kept in meshing engagement with the internal tooth (4), causing the output shaft to be rotated at a reduced speed. The root radius of the internal gear (3), the radius of the circumcircle of the rolling bearing (11), the circumcircle having a center lying on the center axis of the input shaft (7), and the outer diameter of the rollers (19) are measured beforehand, and determined such that the smallest one of roller gaps (20) defined between the rollers (19) and the tooth bottoms of the internal gear (3) are controlled to reduce vibration.