Ball Screw Anti-Rotation Guide with Self-Aligning Groove Contact
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Solution Overview
Problem
Existing anti-rotation devices in ball screw drives for automated manual transmissions experience significant wear due to tolerances, friction pairings, and uneven surface pressure, leading to reduced component lifespan and increased maintenance costs.
Innovation Solution
The anti-rotation device features a securing element with protrusions that engage with guide elements having grooves, allowing for increased contact surface area and alignment to distribute rotational forces, reducing wear and maintaining anti-rotation functionality with minimal installation space and material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a locking element is guided in grooves of a guide sleeve with a closed cross-sectional profile, then the anti-rotation function is achieved, but significant wear occurs between the locking element and the groove due to tolerances, friction pairs, and uneven surface pressure
Solution Approach 1:
The guide element is designed with rotational freedom about its longitudinal axis, allowing it to dynamically adjust its orientation during operation. This dynamic capability enables the guide element to align itself with the locking element, optimizing the contact area and distributing surface pressure more evenly, thereby reducing wear while maintaining the anti-rotation function
Solution Approach 2:
The invention changes the contact parameters by transitioning from a fixed guide sleeve with closed cross-section to a guide element with open cross-section that can rotate. This parameter change allows the contact area between the locking element and guide element to increase, reducing surface pressure and wear while preserving the anti-rotation functionality
2Adaptability or versatility
If the guide element is designed as a thin sheet metal part clamped on one side and free on the opposite side, then the guide sleeve can twist slightly to accommodate rotation, but this results in very small contact area between the locking element and the housing, causing high wear
Solution Approach 1:
The guide element is designed with rotational freedom about its longitudinal axis, allowing it to dynamically adjust its orientation during operation. This dynamic capability enables the guide element to align itself with the locking element, optimizing the contact area and distributing surface pressure more evenly, thereby reducing wear while maintaining the anti-rotation function
Solution Approach 2:
The invention employs a composite structural approach by combining the guide element with different rotational constraints - fixed at one end and free to rotate about its longitudinal axis at the other. This composite constraint system allows the structure to accommodate rotational movements while maintaining optimal contact area, preventing the high wear associated with the previous design
Data Source
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AI summary
The present invention relates to an anti-rotation safeguard of an axially moving element, and to a ball screw drive with an anti-rotation safeguard, in particular for use in an automated manual transmission (AMT) for the conversion of rotational into translational movement. The ball screw has a spindle (3), a nut (4) which rotates on balls around the spindle (3), at least one securing element (2) which is provided in the spindle (3), and at least one guide element (5) which, in a groove, guides a part of the securing element (2) along the longitudinal direction of the spindle (3), which part projects out of the spindle (3). Here, the at least one securing element (2) and the at least one guide element (5) with the groove are the anti-rotation safeguard. In the case of a translational movement of the spindle (3) in its longitudinal direction, a rotation of the spindle (3) can be prevented by way of the guidance of the securing element (2) in the groove of the at least one guide element (5). Here, the at least one guide element (5) is accommodated in a cut-out of the enclosure and can rotate about its longitudinal axis. An alignment of the at least one guide element (5) can be achieved by way of the open degree of rotational freedom, as a result of which an introduction of force via the securing element (2) and the groove into the guide element (5) over as large as possible a surface area is ensured, and therefore the wear of the groove of the at least one guide element (5) and of the securing element (2) can be reduced.