Friction Roller Transmission Holding Device Axial Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Friction roller-type transmissions face challenges in maintaining dynamic balance and power transmission efficiency at high speeds due to centrifugal forces, leading to increased vibration and noise, especially when rotating at ultrahigh speeds exceeding 30,000 rpm, where the strength of holding devices is compromised and precise dynamic balance correction is difficult.
Innovation Solution
The friction roller-type transmission incorporates a holding device with guide protrusions and guide grooves that maintain axial position and prevent inclination, combined with a cam mechanism that adjusts contact pressures based on rotary torque, ensuring balanced operation and reduced sliding resistance across rollers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the input shaft rotates at high speed, then power transmission capability is improved, but centrifugal force increases causing thrust to be applied to the sun roller element and cam ring, lowering power transmission efficiency
Solution Approach 1:
A holding device is introduced as an intermediary component between the sun roller element and the cam ring. This holding device has a pocket that receives the rolling element and is configured to absorb the thrust generated by centrifugal force during high-speed rotation. The holding device acts as a mediator that isolates the thrust from the sun roller element and cam ring, preventing the thrust from affecting power transmission efficiency while allowing the system to operate at high speeds with improved power transmission capability
2Loss of energy
If a holding device is provided to suppress thrust, then power transmission efficiency is improved, but the axial position and inclination of the holding device must be precisely restrained, increasing device complexity
Solution Approach 1:
The holding device is merged with the existing cam mechanism structure. The pocket of the holding device is formed as an integral part of the cam ring structure, and the holding device shares the rotational motion with the cam ring. This merging approach allows the holding device to suppress thrust effectively while minimizing additional structural complexity, as the holding device utilizes the existing rotational framework rather than requiring a completely separate positioning and inclination restraint system
3Reliability
If the rolling element is held on the cam surfaces, then the loading cam mechanism functions correctly, but excessive thrust is applied to the sun roller element and cam ring at high speeds, increasing loss of transmission
Solution Approach 1:
The holding device with its pocket serves as an intermediary that modifies the interaction between the rolling element and the cam surfaces. The pocket receives and holds the rolling element in a controlled manner, allowing the loading cam mechanism to function correctly by maintaining proper contact between the rolling element and cam surfaces, while simultaneously absorbing the excessive thrust generated at high speeds. This intermediary function prevents the thrust from being transmitted to the sun roller element and cam ring, thereby reducing transmission loss while preserving mechanism functionality
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 achieves excellent dynamic balance and maintains power transmission efficiency at high speeds by restricting axial position and inclination of the holding device, reducing vibration and noise, and allowing for precise adjustment of contact pressures to prevent excessive sliding.
Implementation Method 1
When the input shaft 5 rotates at high speed, a high centrifugal force is applied to the rolling elements 8 of the loading cam mechanism 9
Implementation Method 2
respective facing surfaces of the cam ring 6 and the sun roller element 2B are formed with cam surfaces 7 at a plurality of places along a circumferential direction
Implementation Method 3
The friction roller-type transmission incorporates a holding device with guide protrusions and guide grooves that maintain axial position and prevent inclination
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A sun roller of a friction roller-type transmission includes a movable sun roller element (23) capable of moving in an axial direction. Furthermore, the sun roller is provided with a loading cam mechanism which is formed along the circumferential direction of an input shaft (12), the loading cam mechanism having a first cam surface (75), a second cam surface (77) arranged facing the first cam surface (75) and secured to the input shaft (12), rolling elements (63) held between the first and second cam surfaces (75, 77), and an annular holding device (51), and the loading cam mechanism axially displacing the movable sun roller element (23). The holding device (51) has an inside-diameter-surface guiding part (81) for positioning the holding device relative to the input shaft by being fitted over the input shaft, the guiding part being provided to the inside diameter surface.