Roller Screw Diagonal Scooping Guide for Jam Prevention
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Solution Overview
Problem
Conventional roller screws face issues with rollers colliding with the edge of the scooping portion during transfer from the unloaded return path to the loaded roller rolling path, leading to potential jamming and breakage, and also experience skewing due to inadequate constraint areas.
Innovation Solution
The design incorporates a scooping portion with diagonal corresponding parts that gradually narrow to securely guide rollers into the unloaded return path, and includes retainers and a lip portion with specific cross-sectional shapes and orientations to prevent collisions and skewing, ensuring smooth roller movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the unloaded return path is arranged in the tangential direction of the loaded roller rolling path, then the scooping portion can be positioned to guide rollers, but the scooping portion cannot be close enough to the loaded roller rolling path without compromising structural strength
Solution Approach 1:
The scooping portion is positioned not only in the tangential direction but also extended in the axial direction of the nut. This multi-dimensional positioning allows the scooping portion to be close to the loaded roller rolling path while maintaining sufficient thickness for structural strength.
2Manufacturing precision
If the lip portion is formed with narrowed entry to guide rollers, then roller alignment is improved, but rollers may collide with the lip portion edge causing breakage or jamming
Solution Approach 1:
The scooping portion is positioned to scoop rollers before they reach the lip portion, pre-aligning them in the unloaded return path. This preliminary action prevents rollers from colliding with the lip portion edge, eliminating breakage and jamming risks.
3Ease of operation
If the scooping portion is positioned closer to the loaded roller rolling path, then roller constraint is improved, but the scooping portion may contact the screw shaft
Solution Approach 1:
The scooping portion is positioned in both the tangential direction and the axial direction, allowing it to extend close to the loaded roller rolling path while the axial offset prevents contact with the screw shaft.
4Ease of operation
If the unloaded return path diameter is larger than the loaded roller rolling path diameter, then clearance is provided for roller movement, but a difference in diameters requires tapered lip portion design
Solution Approach 1:
The scooping portion pre-aligns rollers in the unloaded return path before they enter the loaded roller rolling path. This preliminary alignment action simplifies the lip portion geometry by eliminating the need for complex tapered designs to achieve proper roller orientation.
Data Source
AI summary
Provided is a roller screw capable of preventing rollers moving from an unloaded return path to a loaded roller rolling path from coming into collision with a scooping portion. The roller screw has: a screw shaft 1 having a spiral roller rolling surface 1a formed on an outer peripheral surface thereof; a nut 2 having a loaded roller rolling surface 2a formed in an inner peripheral surface thereof; a circulation member 3 having an unloaded return path connecting one end of the loaded roller rolling surface 2a of the nut 2 to an opposite end thereof; and a plurality of rollers 4 arranged in a loaded roller rolling path 6 and the unloaded return path. In the circulation member 3, as a scooping portion that juts toward the screw shaft 1 and provided for scooping the rollers 4 moving in the loaded roller rolling path 6 up into the unloaded return path, a pair of diagonal corresponding parts 14 is provided which are in contact with diagonal parts 4e of a rectangular side surface of each roller 4 and a width between which is gradually narrower as they are deeper in the unloaded return path in such a manner that a cross section of the unloaded return path is closer to a rectangle.