Ball Screw Recirculation Shell Assembly Without Sleeve Fasteners
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Solution Overview
Problem
The existing ball screw drive systems, particularly the ball deflection devices, are complex and costly to manufacture and assemble, requiring multiple parts and a sleeve for securement, which can lead to unreliable ball guidance and assembly challenges.
Innovation Solution
A simplified ball deflection device design using two main components, an upper shell and a lower shell, which are fastened within the spindle nut without additional mechanical fasteners, utilizing a clip mechanism or welding for secure attachment, and optionally an expanded upper shell that forms an integral part of the spindle nut for enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sleeve is used to secure the ball deflection device, then the ball guidance is supported, but the assembly complexity and manufacturing costs increase
Solution Approach 1:
The invention extracts and eliminates the sleeve component from the ball deflection device assembly. The ball deflection device is designed to be directly secured to the spindle nut body through integrated mounting features, removing the intermediate sleeve that previously complicated the assembly while maintaining secure attachment and reliable ball guidance.
Solution Approach 2:
The invention merges the ball deflection device with the spindle nut structure by integrating mounting features directly into the nut body. The ball deflection device and spindle nut are combined into a more unified assembly, eliminating the need for separate fastening components like the sleeve and reducing the total part count.
2Reliability
If a sleeve is used to hold the ball deflection device, then the components are secured, but the assembly process becomes more difficult and time-consuming
Solution Approach 1:
The sleeve component is extracted from the assembly, eliminating the time-consuming process of fitting and securing the sleeve over the ball deflection device. The direct mounting approach allows for faster assembly while maintaining component security through integrated features.
Solution Approach 2:
The ball deflection device is designed with pre-integrated mounting features that are prepared during manufacturing. These preliminary actions enable the device to be directly attached to the spindle nut without requiring the additional step of installing a sleeve, thereby reducing assembly time while ensuring secure component attachment.
3Stability of the object's composition
If a sleeve is used to fasten the ball deflection device, then the structure is stabilized, but the manufacturing costs increase
Solution Approach 1:
The sleeve component is removed from the design, eliminating the manufacturing costs associated with producing and procuring this separate part. The structural stability previously provided by the sleeve is achieved through integrated mounting features built into the spindle nut and ball deflection device, reducing overall manufacturing complexity and cost.
Solution Approach 2:
The mounting features are merged into the existing spindle nut and ball deflection device structures. This consolidation eliminates the need for separate fastening components, reducing the total number of parts to manufacture and assemble, thereby lowering manufacturing costs while maintaining structural stability.
Data Source
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AI summary
A ball screw drive consisting of a threaded spindle and a spindle nut features a ball recirculation system located in an opening in the outer surface of the spindle nut. This recirculation system is at least two-part, comprising an upper shell and a lower shell, with the lower shell positioned radially closer to the longitudinal axis of the spindle nut than the upper shell. The lower shell has a substantially semi-shell-like contour. Both the upper and lower shells are secured in the spindle nut without any additional, discrete mechanical fasteners, and the resulting ball recirculation system does not protrude beyond the outer contour defined by the spindle nut. Various fastening methods are described, as well as different versions of the upper shell, e.g., in metal and plastic.