Drive Flange Protective Plate Against Bolt Loosening From Road Impact

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In drive devices for vehicles, external forces from the road surface can cause loosening of bolts at the connecting parts between the gearbox and rotary electric machine, leading to misalignment of rotation axes and issues in motive power transmission.

Innovation Solution

A protecting plate made of a rigid material is positioned underneath the connecting parts of the gearbox and rotary electric machine flanges, ensuring that external forces are absorbed by the plate before reaching the bolts, thereby minimizing the risk of loosening and misalignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If an undercover is provided underneath the drive device to protect against road surface contact, then protection against minor external forces is improved, but the connecting part of the flange remains vulnerable to major external forces from below causing bolt loosening

Engineering Contradiction:
Improveprotection against road surface contactVSAvoidbolt connection stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

A protecting plate is introduced as an intermediary component between the undercover and the flange connecting part. This plate specifically targets and blocks major external forces from below before they reach the bolts, while the undercover continues to provide general protection against road surface contact. The protecting plate acts as a specialized mediator that addresses the specific vulnerability of the connecting part without compromising the overall protection system.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of making the entire undercover more rigid or thicker, the invention applies a localized protecting plate only at the critical connecting part of the flange. This local quality approach provides enhanced protection exactly where needed (at the bolt connection) while maintaining the lightweight and cost-effective characteristics of the resin undercover in non-critical areas.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If the lower surface of the gearbox flange is positioned lower than the rotary electric machine flange, then the protecting plate can effectively intercept external forces, but the structural design becomes more complex

Engineering Contradiction:
Improveexternal force interceptionVSAvoidflange positioning structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The protecting plate is designed with a predetermined shape and positioning features that enable it to be pre-installed in the correct location and orientation. The plate's geometry is预先 designed to automatically align with the flange connecting part, and its shape is optimized to intercept external forces from below before they reach the bolts, eliminating the need for complex real-time adjustments or complex structural designs.

Inventive Principle:
Principle #10Preliminary action

3Strength

If a protecting plate made of rigid material is added to the undercover, then protection against major external forces is improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveprotection against major external forcesVSAvoidundercover assembly
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The protecting plate is designed as a separate, modular component that can be manufactured independently from the resin undercover using appropriate metal forming processes. This segmentation allows each component to be optimized for its specific manufacturing process and quality requirements, and simplifies assembly by allowing the protecting plate to be installed as a distinct module rather than requiring complex integration into the undercover structure.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4163520B1Protective structure for drive device
Publication Date: 2023.12.27 NISSAN MOTOR CO LTD
  • EP4163520B1 patent drawingFigure 1
  • EP4163520B1 patent drawingFigure 2
  • EP4163520B1 patent drawingFigure 3

AI summary

A rotary electric machine and a gearbox are connected to each other by a rotary electric machine flange of a rotary electric machine housing and a gearbox flange of a gearbox housing. The rotary electric machine flange and the gearbox flange are formed such that a lower surface of the gearbox flange is positioned lower than a lower surface of the rotary electric machine flange. An undercover is provided with a protecting plate formed of a material more rigid than a material of the undercover. The protecting plate is provided on an underside of a part linking the rotary electric machine flange and the gearbox flange, and is provided facing the connecting part.