Rolling Torque Coupling for Parallel Offset Shafts

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing power transmission couplings between parallel offset axes often require large and complex components to maintain constant speed and torque, especially when the distance between shafts is small, leading to inefficiencies and high frictional losses due to sliding contact.

Innovation Solution

A torque coupling design featuring a centre member and side members with congruent holes, utilizing torque transfer elements like cylindrical, elliptical, or spherical rollers that rotate about a third axis parallel to both main and secondary axes, enabling smooth rolling contact for efficient torque transfer without speed or direction change.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If gears, chains, sprockets and belts are used to transfer power between parallel offset axes, then power transfer is achieved, but the components become large and complex when no speed difference is required

Engineering Contradiction:
Improvecomplexity of power transfer componentsVSAvoidmaintaining constant speed and torque
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The coupling is divided into three separate members (centre member, left side member, right side member) that can be manufactured and assembled independently. Each member contains holes positioned at specific radii, and the torque transfer elements connect these members without requiring them to be a single complex component. This segmentation allows for simpler individual parts while achieving the overall function of constant speed and torque transfer between parallel offset axes.

Inventive Principle:
Principle #1Segmentation

2Length of moving object

If the distance between two rotating shafts is relatively small, then compact design is achieved, but prior art requires large and complex components to continuously transfer power

Engineering Contradiction:
Improvedistance between shaftsVSAvoidsize of power transfer components
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The invention introduces a third axis of rotation for the torque transfer elements that is midway between the main axis and secondary axis. This dimensional approach allows the torque transfer elements to rotate about an intermediate axis, enabling effective torque transfer even when the distance between the parallel shafts is small. The torque transfer elements engage with holes in all three members through this intermediate rotational dimension, solving the problem of component size in compact configurations.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Power

If sliding contact is used for torque transfer, then torque can be transferred between axes, but frictional losses increase

Engineering Contradiction:
Improvetorque transfer capabilityVSAvoidfrictional losses
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The torque transfer elements are designed with curved surfaces (cylindrical, elliptical, or spherical rollers) that enable rolling contact between the centre member and side members. This curvature allows the elements to roll rather than slide during torque transfer, significantly reducing frictional losses while maintaining effective torque transmission capability between the parallel offset axes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention replaces the traditional sliding contact mechanism with a rolling contact mechanism using torque transfer elements. This substitution transforms the mechanical interaction from high-friction sliding to low-friction rolling, reducing energy losses while maintaining the ability to transfer torque between the parallel offset axes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 allows for efficient torque transfer between parallel offset axes with minimal frictional losses, maintaining constant speed and direction, and can be compactly integrated with gear sets, enhancing packaging efficiency and reducing the need for secondary gear sets.

Implementation Method 1

transfer torque between the centre member and the side members through rolling contact between the torque transfer elements and the holes of the centre and side members

Methodology Applied
Scientific EffectRolling contact: Roller

Data Source

PatentEP3177841B1One-to-one torque coupling
Publication Date: 2022.03.09 KER TRAIN HLDG
  • EP3177841B1 patent drawingFigure 1~2
  • EP3177841B1 patent drawingFigure 3
  • EP3177841B1 patent drawingFigure 4(a)~4(b)

AI summary

A one-to-one torque coupling includes a centre member, left and right side members, and a plurality of torque transfer elements. The centre member is disposed between the side members, has a main axis of rotation and includes a plurality of holes disposed about the main axis at a radius. The side members each have a common secondary axis of rotation that is parallel to and offset from the main axis. Each side member also includes a plurality of holes that are congruent with the holes in the centre member and are disposed about the secondary axis at the radius. The torque transfer elements extend through the holes of the centre member into the holes of the side members, and rotate about a third axis that is parallel to and disposed midway between the main axis and the secondary axis. The torque transfer elements transfer torque between the centre member and the side members through rolling contact between the torque transfer elements and the holes of the centre and side members.