Ball Screw Circulation Component Positioning With Three-Point Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing screw devices face challenges in managing the tolerance of the contact area between the circulation component and the nut's recess, making it difficult to ensure proper alignment and circulation of rolling elements.
Innovation Solution
The screw device incorporates a circulation component housed in a recess of the nut with clearance, where the component is secured by a lid member using fastening means, allowing the centrifugal force of rolling elements to bring it into contact at multiple points, thereby stabilizing its position without the need for fixed fastening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the circulation component is fitted into the recess of the nut within predetermined tolerance, then the contact area between the circulation component and the recess is increased, but it becomes difficult to manage the tolerance of the large contact portion
Solution Approach 1:
The invention changes the contact configuration from a large-area continuous contact to discrete point contacts. Specifically, the circulation component is designed to contact the recess at three specific points (first, second, and third contact points) rather than across a large surface area. This localizes the contact quality requirements to specific points, making tolerance management much easier while still ensuring reliable positioning through the combined effect of multiple points.
Solution Approach 2:
The contact interface is segmented into three distinct contact points rather than a continuous contact area. The circulation component has a circumferential length that is intentionally limited so that it contacts the recess at discrete locations. This segmentation transforms the tolerance management problem from managing a large continuous area to managing three separate points, significantly reducing complexity.
2Ease of manufacture
If the circulation component is housed in the recess with clearance, then it is easy to house the circulation component, but the position of the circulation component needs to be fixed without fastening means
Solution Approach 1:
The invention changes the parameter of circumferential length of the circulation component to a specific range (0.05D to 0.2D, where D is the nut's outer diameter). This parameter optimization ensures that the component is short enough to contact the recess at only three discrete points rather than along a long arc, enabling stable positioning through point contacts without requiring fastening means. The clearance housing combined with this specific length parameter achieves both ease of assembly and position stability.
3Stability of the object's composition
If the circulation component is fixed to the nut using a screw, then the position is secured, but the complexity of the structure and assembly increases
Solution Approach 1:
The invention extracts and eliminates the fastening means (screw) from the structure by designing the circulation component to be self-retaining through its geometric configuration. The component's circumferential length and contact point arrangement create sufficient positional stability that mechanical fastening is unnecessary. This removes the screw and associated fastening holes, simplifying both the structure and assembly process while maintaining position fixation.
Solution Approach 2:
The circulation component serves its own positioning function through its geometric design rather than requiring an external fastening mechanism. The three-point contact configuration with the recess, combined with the specific circumferential length, enables the component to self-stabilize in the correct position. The structure is self-sufficient, eliminating the need for separate fastening elements and reducing overall complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design simplifies the housing of the circulation component and ensures smooth circulation of rolling elements, as the centrifugal force maintains the component's position, reducing the complexity of managing tolerances to just the contact points, thus facilitating easier assembly and operation.
Implementation Method 1
upon a centrifugal force acting on a rolling element moving along the circulation path, the circulation component comes into contact at at least three points with the recess, or the recess and the lid member
Data Source
AI summary
A screw device is provided which can facilitate management of a tolerance of a recess where a circulation component is housed. A circulation component is housed in a recess of a nut with clearance. At least part of the circulation component is blocked by a lid member fixed to the nut by fastening means. Upon a centrifugal force acting on a rolling element moving along a circulation path in the circulation component, the circulation component comes into contact at three points with the recess as viewed in an axial direction.