Ball Screw Preload Module for In-Place Accuracy Adjustment
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Solution Overview
Problem
Current double-nut ball screw devices require disassembly for preload adjustment, increasing operation time and cost, and affecting production capacity due to manufacturing tolerances and the need for preload spacers.
Innovation Solution
A linear motion system with a preload adjusting module that includes a preload assembly and regulator, allowing for adjustment of preload values without disassembly, using a thrust mechanism to adjust the preload value generated by rolling members, and incorporating a preload sensing member and monitoring device for real-time feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a preload spacer is added between two nuts to achieve sufficient offset for preload, then the preload function is improved, but the total number of components increases and manufacturing tolerance accumulates, worsening positioning accuracy
Solution Approach 1:
The preload adjustment function is merged into the nut structure itself through the adjustable groove design. The groove can be positioned at different depths to provide different offset values, eliminating the need for separate preload spacers. This integration reduces the total number of components and eliminates additional tolerance accumulation from multiple parts, while maintaining the preload function.
Solution Approach 2:
The groove depth parameter is made variable to adjust the offset between balls and nuts. By changing the groove depth, different preload values can be achieved without adding or removing components. This parameter adjustment allows optimization of the preload function while maintaining high positioning accuracy through reduced component tolerance accumulation.
2Reliability
If the ball screw device is disassembled to adjust or replace components for preload correction, then the preload issue is resolved, but operation time and cost increase significantly, reducing production capacity
Solution Approach 1:
The system provides self-adjustment capability through the adjustable groove design. The groove can be repositioned or reconfigured without disassembling the entire ball screw device. This self-service feature allows operators to correct preload issues quickly by simply adjusting the groove position, eliminating the need for time-consuming disassembly and reassembly operations, thereby maintaining high production capacity.
Solution Approach 2:
The groove position is made dynamically adjustable rather than fixed. This dynamic design allows the offset between balls and nuts to be modified in situ without disassembly. The ability to change the groove position on-demand enables quick preload correction during operation or maintenance, significantly reducing downtime and preserving production capacity.
3Device complexity
If the number of components is reduced by eliminating the preload spacer, then device complexity is lowered, but achieving sufficient offset for preload becomes more difficult
Solution Approach 1:
The adjustable groove is placed locally within the nut structure at the specific location where offset adjustment is needed. This localized feature allows the groove to provide the necessary offset between balls and nuts without requiring a separate preload spacer component. The local quality modification maintains the preload function while reducing overall device complexity.
Data Source
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AI summary
A linear motion system comprises a guiding member, a moving member, a plurality of rolling members and a preload adjusting module. The moving member is slidably disposed on the guiding member. The moving member and the guiding member together form a circulation path. When the guiding member moves with relative to the moving member, the moving member can generate a linear movement with relative to the guiding member. The rolling members are accommodated in the circulation path. The preload adjusting module is disposed on the moving member, and comprises a preload assembly and a preload regulator. The preload regulator applies a thrust to the preload assembly to adjust a preload value generated by the rolling members and applied to the moving member.