Rotation Transmission Assembly With Snap Ring Axial Restraint

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Solution Overview

Problem

Existing rotation transmission devices fail to reliably restrict the movement of the inner member toward the other axial end relative to the inner ring of the rolling bearing, leading to potential malfunctions of the clutch mechanism under excessive axial loads.

Innovation Solution

The rotation transmission device incorporates a second snap ring attached to the inner member and a shaft connected to the outer member, with a telescopically fitted portion and an engagement wall, to restrict movement of the inner member and prevent pullout, ensuring coaxial alignment and torque transmission while preventing abnormal contact between the rotor and armature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If only press-fitting of the inner ring to the end portion of the inner member is used to restrict movement, then the device structure remains simple, but the inner member may be pulled out under excessive axial loads causing clutch mechanism malfunction

Engineering Contradiction:

Improveprevention of inner member pulloutVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The axial restraint function is segmented between two components: the press-fitted inner ring provides primary restraint, while the snap ring provides secondary restraint. This division allows each component to perform its specific function optimally without requiring one component to handle all restraint forces, thereby improving reliability without excessive complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The snap ring is pre-installed on the inner member before final assembly with the inner ring. This preliminary action ensures that the snap ring is already in position to prevent pullout, and the inner ring is then press-fitted to lock the snap ring in place, creating a redundant restraint system that enhances reliability

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If the inner member is allowed to move axially under excessive load, then the device can accommodate abnormal conditions, but the clutch mechanism components move improperly causing malfunction

Engineering Contradiction:

Improvetolerance to abnormal axial loadsVSAvoidclutch mechanism proper operation

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The snap ring acts as a protective measure installed beforehand to cushion against the harmful effect of excessive axial loads. By providing this preliminary protective barrier, the system can tolerate abnormal load conditions without allowing the inner member to pull out and cause clutch mechanism malfunction

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If a snap ring is attached to the inner member to prevent pullout, then movement restriction is improved, but the assembly process becomes more difficult

Engineering Contradiction:

Improveprevention of inner member movementVSAvoidassembly difficulty

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The snap ring is installed on the inner member before the final assembly step where the inner ring is press-fitted. This preliminary installation makes the snap ring placement easier, as the inner ring's subsequent press-fitting action automatically locks the snap ring in its grooves, simplifying the overall assembly process while ensuring reliable movement restriction

Inventive Principle:

Principle #10Preliminary action

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 configuration effectively prevents malfunction of the clutch mechanism by restricting the inner member's movement and maintaining coaxial alignment, even under axial loads, ensuring reliable operation of the electromagnetically controlled engaging elements.

Implementation Method 1

a rolling bearing (3) disposed between the inner peripheral portion (2a) and an end portion (1a) of the inner member (1) at one axial end

Methodology Applied

Scientific EffectRolling bearing: Ball Bearing

Implementation Method 2

a clutch mechanism for electromagnetically switching the state of the engaging elements between an engageable state in which the engaging elements can engage with the inner and outer members, and an unengageable state in which the engaging elements cannot engage with the inner and outer members

Methodology Applied

Scientific EffectElectromagnetic force: Electromagnet

Data Source

PatentUS11965562B2Rotation transmission device

Publication Date: 2024.04.23 NTN CORP

AI summary

An outer member of a rotation transmission device has an opening integral with an inner peripheral portion of the outer member. Engaging elements are disposed between an inner member and the inner peripheral portion. An outer ring is fitted to the inner peripheral portion. A first snap ring is attached to the inner peripheral portion. An inner ring is fitted to an end portion of the inner member at one axial end thereof. A second snap ring is attached to the end portion through the opening. A shaft is connected to the opening so as to be rotatable in unison with and coaxially with the outer member.