Rolling Bearing Wedge Preload Assembly for Stable Rigidity
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Solution Overview
Problem
Existing rolling bearing preloading methods face challenges such as increased complexity, cost, and maintainability issues, particularly with fixed position preloading, where preload changes due to thermal expansion and axial loads lead to accuracy deviations and creep, and hydraulic mechanisms complicate the structure.
Innovation Solution
The method employs wedge members between the outer and inner rings and the housing/rotating shaft to apply a fixed position preload, leveraging the wedge effect to firmly fix the rings without increasing the bearing mechanism's size or impairing maintainability, allowing for adjustable rigidity and resistance to displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If fixed position preloading is used to obtain higher rigidity, then the rigidity is improved, but the preload amount changes due to thermal expansion and dimensional changes, causing excessive preload or loss of preload
Solution Approach 1:
The invention uses a preload adjustment ring with a coefficient of thermal expansion different from the inner ring spacer to compensate for dimensional changes. By selecting materials with appropriate thermal expansion coefficients, the system maintains consistent preload under temperature variations and axial loads, resolving the contradiction between rigidity and preload consistency.
2Reliability
If a preload adjustment ring with different thermal expansion coefficient is provided to cancel preload change, then preload consistency is improved, but the number of parts increases and the structure becomes complicated
Solution Approach 1:
The preload adjustment ring is integrated into the existing bearing assembly structure, combining the functions of preload adjustment and thermal compensation into a single component that works with the inner ring spacer. This merging approach maintains preload consistency without significantly increasing the number of parts or structural complexity.
3Strength
If hydraulic mechanism is used to preload rolling bearing, then rigidity can be maintained and changed, but the mechanism becomes large and the structure becomes complicated
Solution Approach 1:
The invention extracts the essential function of rigidity control from complex hydraulic mechanisms and implements it through a simplified mechanical structure using the wedge member and preload adjustment ring. This extraction eliminates the need for large hydraulic systems while maintaining the ability to control and adjust rigidity through dimensional differences and thermal expansion compensation.
4Device complexity
If press fitting is used to prevent relative movement, then the structure is simple, but the fixing strength against backlash in radial direction is weak, causing accuracy deviation and creep
Solution Approach 1:
The invention applies preliminary action by using the wedge member to create a preload that firmly fixes the inner ring to the rotating shaft and the outer ring to the housing before operation begins. This preliminary fixing through wedge effect and dimensional difference prevents accuracy deviation and creep under load, while maintaining structural simplicity.
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 approach provides a stable and maintainable rolling bearing preloading method that maintains preload consistency across temperature changes and axial loads, ensuring high accuracy and rigidity without the need for complex hydraulic mechanisms or additional processing, thus reducing costs and simplifying assembly and disassembly.
Implementation Method 1
at least one of the outer ring and the inner ring of the bearing can be directly and firmly fixed to at least one of the housing and the rotating shaft by the wedge effect of the wedge member
Data Source
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AI summary
In the present invention, in a housing that supports a rotating shaft via a rolling bearing which is subjected to predetermined position precompression, a wedge member, the radial thickness of which increases from the leading end towards the base end thereof, is inserted between the housing and the outer circumferential surface of the outer race of the rolling bearing and between the rotating shaft and the inner circumferential surface of an inner race of the rolling bearing, the wedge member being inserted from the leading end thereof along the radial direction of the rotating shaft. The wedge member is fixed by being fastened, ahead in the insertion direction, by bolts and nuts, so that precompression force along with predetermined position precompression is imparted to the rolling bearing.