Ball Spline Bypass Track Structure for Nut Rotation and Bending Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ball splines do not allow the nut to rotate with respect to the spline shaft, leading to potential damage from ball contacts and interference with the spline shaft during movement.
Innovation Solution
The ball spline with detour tracks features a bar-shaped spline shaft, a cylindrical nut, and retainer components with load and non-load circulating grooves, where the detour tracks are formed deeper and inclined to allow the balls to move between the load and detour tracks, enabling the nut to rotate by creating gaps and reducing contact points, thus enhancing bending resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the nut is constrained to move only linearly along the spline shaft, then the structure is simple and manufacturing is easy, but the nut cannot rotate with respect to the spline shaft causing ball contact damage and interference
Solution Approach 1:
The track is segmented into multiple sections: load-bearing track sections for supporting balls during linear motion, and detour track sections that allow balls to bypass restricted zones. This segmentation enables the nut to rotate relative to the spline shaft while maintaining proper ball circulation and preventing contact damage.
Solution Approach 2:
The detour track acts as an intermediary path for the balls, allowing them to bypass the restricted zone where the nut and spline shaft interfaces prevent direct ball passage. This intermediary track enables rotational movement without causing ball interference or damage.
2Ease of manufacture
If the track groove is machined with standard arch-shaped sections, then manufacturing is straightforward, but balls make 4-point contacts causing damage during movement
Solution Approach 1:
The track groove is designed with different local geometries: standard arch-shaped sections where balls make stable 2-point contacts, and detour track sections with modified geometry to guide balls through bypass paths. This local differentiation maintains manufacturing simplicity while improving ball contact stability and preventing damage.
3Ease of operation
If balls are allowed to circulate freely between load tracks and non-load circulating holes, then linear motion is smooth, but balls interfere with the spline shaft during nut movement
Solution Approach 1:
The detour track extracts the problematic portion of ball circulation by creating a separate bypass path that removes balls from the interference zone. This allows the main load-bearing tracks to maintain smooth linear motion while the detour path prevents ball interference with the spline shaft during nut movement.
Data Source
AI summary
A ball spline with detour tracks includes spline shaft, nut part movable along a longitudinal direction of the spline shaft, and balls between the nut part and the spline shaft, wherein the nut part includes nut adapted to insert the spline shaft thereinto and retainers on longitudinal sides of the nut, the spline shaft includes tracks extended along the longitudinal direction, the nut includes load track grooves formed in longitudinal direction on inner peripheral surface into which the spline shaft is inserted and non-load circulating portions formed in the longitudinal direction, each retainer includes circulating grooves on the inner peripheral surface to face the load track groove and non-load circulating portion, the balls run between the tracks and the load track grooves, and each track includes track groove formed in longitudinal direction of the spline shaft and detour tracks whose longitudinal sides are connected to the track groove.