Rotation Transmission Device Spring Support Design

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing rotation transmission devices face difficulties in easily mounting elastic members due to interference issues and potential deformation of spring holders, which affects the reliable engagement of the two-way clutch, and handling is complicated by exposed lead wires.

Innovation Solution

The design includes plate-shaped spring support pieces with gaps for easy insertion of elastic members and omits the lead wire by using a detachable male connector, ensuring accurate engagement and improved handling by encapsulating the electromagnetic coil.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If elastic members are inserted into through holes perpendicular to the length direction of the bars, then the elastic members are constrained to prevent radial movement, but the bars interfere with the elastic members during insertion, making mounting difficult

Engineering Contradiction:
Improvestable position of elastic membersVSAvoidease of mounting elastic members
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the insertion direction of elastic members from a direction perpendicular to the bars (through holes in spring support pieces) to a direction parallel to the bars (through gaps between adjacent bars). This dimensional change eliminates interference during insertion while still achieving reliable constraint of the elastic members in the radial direction.

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

2Reliability

If the spring holder is rotationally fixed by engagement between flat surfaces, then the spring holder maintains neutral positions of retainers, but the flat surfaces deform or get damaged due to hard collision between bars and protruding pieces

Engineering Contradiction:
Improveaccurate engagement of two-way clutchVSAvoidintegrity of engaging surfaces
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent replaces the mechanical flat-surface engagement system with a magnetic field-based positioning system. The spring holder includes a magnet arranged to attract the input shaft, providing rotational fixation without physical contact between flat surfaces. This eliminates wear and deformation while maintaining accurate positioning for reliable clutch engagement.

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

3Ease of operation

If lead wires are exposed for connecting the electromagnetic coil, then the electromagnetic clutch can be powered, but handling becomes complicated and the lead wires may get caught on external parts

Engineering Contradiction:
Improvepower connection capabilityVSAvoidhandling complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent nests the lead wires inside the housing, routing them through internal pathways rather than exposing them externally. The electromagnetic coil and its connections are contained within the housing structure, eliminating the problem of exposed lead wires getting caught on external parts while maintaining full power connection capability.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 solution allows for easy and accurate mounting of elastic members and eliminates handling issues by preventing interference and deformation, enhancing the reliability and ease of use of the rotation transmission device.

Implementation Method 1

elastic members mounted between the respective opposed pairs of engaging elements and biasing the respective opposed pairs of engaging elements away from each other toward stand-by positions

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

an electromagnetic clutch configured to move the control retainer in the axial direction when the electromagnet of the electromagnetic clutch is energized

Methodology Applied
Scientific EffectElectromagnetic force: Electromagnet

Data Source

PatentEP2833014B1Rotation transmission device
Publication Date: 2018.07.18 NTN CORP
  • EP2833014B1 patent drawingFigure 1
  • EP2833014B1 patent drawingFigure 2~3
  • EP2833014B1 patent drawingFigure 4~5

AI summary

A rotation transmission device includes a control retainer (16A) and a rotary retainer (16B) having bars (22 and 26) arranged circumferentially alternating with each other such that pockets (27) are defined between the adjacent pairs of bars (22 and 26). A pair of rollers (15) are mounted in each pocket (27) with an elastic member (20) disposed between the pair of rollers (15) such that the pair of rollers (15) are pushed by the respective bars (22 and 26) to their respective disengaged positions when the control retainer (16A) and the rotary retainer (16B) rotate relative to each other. A spring holder (33) is fitted on an input shaft (1) while abutting one axial end surface of an inner ring (13). The spring holder (33) has spring support pieces (37) provided on the outer periphery thereof and preventing radially outward movement of the elastic members (20). The spring support pieces (37) are plate-shaped members disposed radially outwardly of the elastic members to extend in the axial direction in parallel to the outer periphery of the inner ring (13).