Ball Screw Nut Structure With Cylindrical Ball Circulation Path
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Solution Overview
Problem
Existing ball screw devices face issues with smooth circulation of balls due to bent portions in the circulation path, leading to hindered rotation of the nut and screw shaft, and poor workability in assembly.
Innovation Solution
The ball screw device features a circulation path formed along a cylindrical portion of the nut's outer surface, with a gentle bending angle at the boundary between the circulation and connection paths, and a cover that fits onto the nut without protruding, allowing easy assembly and smooth ball circulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the circulation path is formed along a flat surface of the nut main body, then the device size is reduced, but bent portions are formed at the boundary between circulation path and connection path, causing balls to be caught and circulation to be hindered
Solution Approach 1:
The circulation path is formed to follow the curved outer circumferential surface of the nut main body rather than a flat surface. This curvature eliminates bent portions at the boundaries with connection paths, allowing balls to circulate smoothly without being caught, while maintaining a compact device size.
2Reliability
If a tube protrudes from the outer circumference of the nut to form a circulation path, then ball circulation is smooth, but the device size increases
Solution Approach 1:
The circulation path is merged with the outer circumferential surface of the nut main body, eliminating the need for a separate protruding tube. This integration maintains smooth ball circulation while reducing the overall device size.
Solution Approach 2:
The circulation path utilizes the natural curvature of the nut's outer surface, following its cylindrical shape. This curved path design ensures smooth ball flow without requiring additional protruding structures, thus maintaining compact dimensions.
3Device complexity
If the guide plate is fixed to the flat surface of the nut main body, then the circulation path is formed, but bent portions are created at the boundaries, hindering ball circulation
Solution Approach 1:
The guide plate is configured to follow the curved outer circumferential surface of the nut main body. This curved configuration eliminates bent portions at the boundaries with connection paths, ensuring smooth ball circulation while maintaining the circulation path structure.
Data Source
AI summary
A ball screw device includes a nut including a nut main body and a cover, a screw shaft, a rolling path formed by a screw groove of the nut main body and a screw groove of the screw shaft, a circulation path formed by an outer circumferential surface of the nut main body and the cover, a pair of connection paths that allow one end of the circulation path and one end of the rolling path to be communicated with each other and allow the other end of the circulation path and the other end of the rolling path to be communicated with each other, respectively, and a large number of balls disposed in the rolling path, the circulation path, and the pair of connection paths. The circulation path is formed along a cylindrical path of the outer circumferential surface of the nut main body.