Removable Centering Head for Rotor Shaft Axial Assembly

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

During the axial assembly of electric machine and transmission shafts in a motor vehicle powertrain, the risk of damaging the sealing ring exists due to misalignment, where sharp external splines of the rotor shaft can slide along the sealing lips, potentially causing permanent damage.

Innovation Solution

A removable centering head with an ogive-shaped front section and a tubular sleeve is attached to the rotor shaft's free end section, ensuring coaxial alignment with the primary shaft, preventing contact between the splines and sealing lips during assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If axial assembly of rotor shaft and primary shaft is performed without centering aid, then assembly speed is improved, but manufacturing precision deteriorates due to misalignment between splined sections

Engineering Contradiction:

Improveassembly speedVSAvoidcoaxial alignment precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The centering head is attached to the rotor shaft before assembly, performing the centering function in advance. The ogive-shaped front section and tubular sleeve create preliminary alignment conditions that ensure coaxial positioning during the subsequent axial insertion, eliminating the need for slow manual alignment adjustments

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The centering head acts as an intermediary device between the rotor shaft and primary shaft during assembly. The tubular sleeve fits into the complementary axial hole of the rotor shaft, while the ogive-shaped section guides alignment with the primary shaft, mediating the alignment process and preventing direct contact between misaligned splined sections

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If axial assembly is performed without centering aid, then device complexity is reduced, but object-affected harmful factors increase due to risk of sealing ring damage

Engineering Contradiction:

Improveassembly system complexityVSAvoidsealing ring damage risk

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The centering head provides beforehand protection by ensuring proper alignment before the splined sections make contact. The ogive-shaped front section and tubular sleeve act as protective elements that prevent the sharp edges of external splines from directly contacting and damaging the sealing lips during the critical alignment phase

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The centering head serves as a protective intermediary that prevents harmful contact between the rotor shaft splines and sealing ring. By maintaining coaxial alignment through the tubular sleeve and ogive section, it mediates the assembly process to eliminate the harmful sliding contact that would otherwise occur with misaligned shafts

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP3895923B1System to assist with the centring of a rotor shaft and a supplementary primary transmission shaft of an electric power train

Publication Date: 2023.05.03 RENAULT SA

Figure 1
Figure 2
Figure 3

AI summary

The invention proposes a centering aid system for a front free end section (42) of a first shaft (40) inside a second rear free end section (44) of a second complementary hollow shaft (20), which belong in particular to a powertrain group (10), characterized in that the system comprises a removable centering head (62) which is attached to the first front free end section (42) of the first shaft (40).