Discrete Roller Helical Drive for Low-Friction Linear Translation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional worm drives experience significant frictional drag forces and wear due to sliding friction, and existing solutions with rolling elements fail to accommodate engagement and disengagement between screw and nut sections.
Innovation Solution
A discrete roller assembly-based helical drive system featuring a roller worm with discrete roller assemblies arranged in a helical pattern, allowing for engagement and disengagement with an engagement structure, reducing friction through rotational motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a conventional worm gear is used to provide motion transmission, then the mechanism can mechanically translate a payload along an axis, but sliding frictional drag force is generated during operation
Solution Approach 1:
The worm gear is segmented into discrete roller assemblies spaced along the helical path, with each roller assembly containing multiple rollers that contact the rack independently. This segmentation allows the continuous sliding contact of conventional worm gears to be replaced by discrete rolling contacts, reducing sliding frictional drag force while maintaining motion transmission capability
Solution Approach 2:
The sliding friction mechanism is replaced with a rolling friction mechanism by introducing rollers between the worm gear and rack. The rollers convert the sliding contact into rolling contact, substituting the mechanical interaction mode to eliminate sliding frictional drag force while preserving the translational motion function
2Force
If a conventional worm gear is used to lift a payload, then translation along the axis is achieved, but additional fixed frictional drag force is generated from the payload weight
Solution Approach 1:
The lifting force is distributed across multiple discrete roller assemblies spaced along the helical path, with each roller assembly sharing the load. This segmentation reduces the frictional drag force generated by payload weight at any single contact point, as the total weight is distributed over multiple rolling contacts rather than concentrated in a single sliding contact
3Loss of energy
If sliding friction elements are replaced with rolling elements in a ball screw, then frictional losses are reduced, but engagement and disengagement between screw and nut sections cannot be accommodated
Solution Approach 1:
The continuous ball screw mechanism is segmented into discrete roller assemblies spaced along the helical path. This segmentation allows individual roller assemblies to engage and disengage independently from the rack, providing the adaptability and versatility needed for selective engagement while maintaining the low frictional losses of rolling contact through the use of rollers in each assembly
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
The system minimizes frictional losses and wear by utilizing rotational motion, enabling efficient linear translation with reduced power consumption and component degradation.
Implementation Method 1
discrete roller assemblies, each having a respective roller element configured to rotate about a roller assembly axis... reducing friction through rotational motion
Data Source
AI summary
Systems and methods for operation and assembly of a helical drive are provided. A helical drive includes a discrete roller assembly-based roller worm including a body portion and a plurality of discrete roller assemblies disposed in a first helical pattern about the body portion. The helical drive includes an engagement structure including a primary axis, wherein the roller worm is configured to rotate about a central axis to cause linear translation of the roller worm along a length of the engagement structure and the primary axis. The engagement structure includes a plurality of tracks disposed along the length of the engagement structure, where each of the tracks is configured to receive at least one of the roller assemblies during the rotation of the roller worm.