Bearing Locking Assembly for Stable Preload on Shafts
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Solution Overview
Problem
Existing bearing systems face challenges in maintaining a consistent preload, which is essential for balancing the lifetime and performance of bearings. Conventional methods often result in loose fastening or difficulty in controlling the preload amount.
Innovation Solution
A locking system comprising two nuts arranged on a shaft and a locking screw screwed through aligned through holes of both nuts, allowing for controlled application of torque to maintain a consistent preload on the bearing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single nut is used to apply preload to the bearing, then the structure is simple, but the preload cannot be maintained consistently during operation
Solution Approach 1:
The single nut is divided into two separate nuts (first nut and second nut) positioned at different locations on the shaft. The first nut applies preload to the bearing while the second nut serves as a locking element. This segmentation allows the preload application function and the locking function to be separated, enabling consistent preload maintenance without requiring a complex integrated locking mechanism.
Solution Approach 2:
A locking screw is introduced as an intermediary element that passes through the second nut and engages with the first nut. This locking screw acts as a mediator that transfers and maintains the locking force, ensuring that the first nut remains securely positioned against the bearing inner ring throughout operation, thereby maintaining consistent preload.
2Reliability
If conventional fastening methods are used, then the structure is simple, but the fastening becomes loose during operation
Solution Approach 1:
The locking screw is pre-positioned to pass through both the first nut and the second nut before operation begins. This preliminary locking action ensures that the nuts are securely fastened together and to the shaft before the bearing is subjected to operational loads, preventing any loosening during operation.
Solution Approach 2:
The locking screw automatically maintains the locking force through its threaded engagement with the nuts. The spring-loaded or tensioned locking screw continuously applies locking force, making the system self-maintaining without requiring external adjustment or monitoring during operation.
3Reliability
If the preload amount is increased to improve bearing performance, then the bearing lifetime may be reduced due to excessive stress
Solution Approach 1:
The locking system enables precise control of the preload parameter by adjusting the position of the first nut relative to the bearing inner ring. The locking screw and second nut provide a stable reference point that allows the preload force to be set to an optimal value, balancing bearing performance improvement with acceptable stress levels to ensure long lifetime.
4Reliability
If an adjustable locking structure is added to maintain preload, then the preload can be kept unchanged, but the assembly and disassembly becomes more difficult
Solution Approach 1:
The locking structure is segmented into independent components (first nut, second nut, and locking screw) that can be assembled and disassembled separately. This segmentation allows for straightforward sequential assembly and disassembly operations while maintaining the stability of the locked preload position during operation.
Solution Approach 2:
The locking function is extracted as a separate removable component (locking screw) that can be easily inserted and removed. This extraction allows the locking mechanism to be independently adjusted or replaced without affecting the bearing or nuts, simplifying maintenance and assembly operations while ensuring preload stability during normal operation.
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 proposed locking system ensures a reliable and consistent preload on the bearing, maintaining its performance and extending its lifetime while allowing for easy assembly and disassembly.
Implementation Method 1
at least one locking screw adapted to be screwed at least through a first through hole of the second nut and a second through hole of the first nut
Implementation Method 2
The at least one locking screw is adapted to be screwed through the first through hole and the second through hole to apply a second torque to the bearing along the axial direction
Data Source
Figure 1
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AI summary
A locking system (100) and a manufacturing method thereof, a bearing assemble and a robot having the same. The locking system (100) comprises a first nut (110) arranged on a shaft (220) and adapted to contact with an upper side of an inner ring (211) of the bearing (210). The locking system (100) further comprises a second nut (120) arranged on the shaft (220) and separated from the first nut (110) at a predetermined distance. The locking system (100) also comprises at least one locking screw (130) adapted to be screwed at least through a first through hole of the second nut (120) and a second through hole of the first nut (110) while the first through hole and the second through hole are aligned with each other, to thereby apply a force to a bearing (210) on the shaft (220) along an axial direction (X) of the shaft (220). In this way, a reliable fasten solution could be achieved, which may maintain the preload unchanged during the operating of the bearing assembly. Furthermore, this locking structure is easy for assembly and disassembly.