Ball Screw Circulation Assembly Without Bolt Fastening
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Solution Overview
Problem
The existing ball screw devices require a metal plate attachment component and a bolt for retaining the return tube, increasing the number of components and necessitating a threaded hole on the nut, as well as a screw tightening process during assembly.
Innovation Solution
A ball screw device design that incorporates a circulation component with leg parts and a pin component, where the leg parts are inserted into through holes on the nut, and the pin component is provided radially outside to suppress displacement, eliminating the need for a metal plate and bolt, and omitting the need for a threaded hole on the nut.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal plate attachment component and bolt are used to retain the return tube, then the circulation component can be securely fixed, but the number of components increases and the device complexity increases
Solution Approach 1:
The pin component merges the functions of the attachment component and bolt into a single element. The pin has a head portion that contacts the circulation component and a shaft portion that inserts through the through hole, combining the retention and fastening functions that previously required separate metal plate and bolt components.
Solution Approach 2:
The invention extracts and eliminates unnecessary components from the original design. By using the pin component with head and shaft portions, the metal plate attachment component is completely removed, reducing the number of parts while maintaining securing functionality.
2Reliability
If a metal plate attachment component and bolt are used to retain the return tube, then the circulation component can be securely fixed, but the manufacturing process becomes more complex due to threaded hole formation and screw tightening
Solution Approach 1:
The invention removes the threaded hole formation and screw tightening processes by replacing the bolt and attachment component with a pin component. The pin simply inserts through a through hole without requiring threading, eliminating complex manufacturing steps.
Solution Approach 2:
The fastening mechanism changes from threaded connection to simple insertion. The pin component uses a head portion for retention and shaft portion for insertion, changing the connection parameter from threaded engagement to friction fit and geometric constraint, simplifying the manufacturing process.
3Stability of the object's composition
If a pin component is provided radially outside the leg part in an overlapping manner, then the displacement of the circulation component is suppressed, but the structural complexity increases
Solution Approach 1:
The pin component merges the displacement suppression function into the same element that provides retention. The head portion prevents movement in one direction while the shaft portion inserted through the through hole constrains movement in perpendicular directions, combining multiple stabilization functions in one component.
Solution Approach 2:
The pin component is segmented into functional portions: the head portion for preventing displacement in the axial direction and the shaft portion for constraining radial displacement through the through hole. This segmentation allows each portion to address specific stability requirements efficiently.
Data Source
AI summary
A ball screw device includes: a screw shaft the outer peripheral surface of which has a first thread groove; a nut the inner peripheral surface of which is provided with a second thread groove that matches the first thread groove, and the outer peripheral surface of which is provided with a through hole; a plurality of balls that roll between the first thread groove and the second thread groove; a circulation component including a main body part and a pair of leg parts provided on both ends of the main body part, and that is provided on the nut; and a pin component that fixes the circulation component to the nut. Each of the leg parts is inserted into the through hole, the pin component is provided on the leg part in an overlapping manner, and the leg part is retained in the through hole by the pin component.