Sunken Wheel-Side Drive Axle Layout for Wider Bus Aisles

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The narrow aisle width in new energy commercial buses due to large drive motors required for high torque in conventional wheel-side motor drive axles compromises passenger comfort.

Innovation Solution

A sunken wheel-side motor drive axle design where the drive motor assembly is positioned at the bottom of the axle beam, utilizing multi-stage reducers to reduce motor size and space, with brake air chambers determining the aisle width, allowing for increased aisle width and improved passenger comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the size of the drive motor is increased to ensure large driving torque, then the driving torque is improved, but the distance between the two drive motor end faces is reduced, resulting in smaller bus aisle width and low passenger comfort

Engineering Contradiction:
Improvedriving torqueVSAvoidbus aisle width
Core Design Contradiction:
ForceVSLength of moving object

Solution Approach 1:

The drive motor assembly is repositioned from a horizontal arrangement to a vertical arrangement at the bottom of the axle beam. This dimensional change allows the motor to generate large torque vertically while freeing up horizontal space, thereby increasing the distance between drive motor end faces and expanding the bus aisle width for improved passenger comfort.

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

Solution Approach 2:

The drive system is segmented into multiple independent components: the drive motor assembly, multi-stage reducer assembly, and brake assembly. This segmentation allows each component to be optimized independently and arranged in a space-efficient vertical configuration, resolving the contradiction between torque generation and aisle width.

Inventive Principle:
Principle #1Segmentation

2Force

If the size of the drive motor is increased to ensure large driving torque, then the driving torque is improved, but the space occupied by the drive motor assembly is increased

Engineering Contradiction:
Improvedriving torqueVSAvoidspace occupied by drive motor assembly
Core Design Contradiction:
ForceVSVolume of moving object

Solution Approach 1:

The patent employs a nested configuration where the multi-stage reducer assembly is integrated with the brake assembly, and both are vertically arranged around the drive motor assembly. This nesting approach allows multiple functional components to occupy overlapping or adjacent spatial volumes, reducing the overall space occupied by the drive motor assembly while maintaining large torque output capability.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

By transitioning from a horizontal to vertical arrangement, the system utilizes the vertical dimension for torque generation and component stacking, thereby reducing the horizontal footprint and total volume occupied by the drive motor assembly.

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

3Power

If conventional wheel-side motor drive axle design is used with large drive motors, then large driving torque is achieved, but the bus aisle width is reduced and passenger comfort is compromised

Engineering Contradiction:
Improvedriving torqueVSAvoidpassenger comfort
Core Design Contradiction:
PowerVSEase of operation

Solution Approach 1:

The drive motor assembly is repositioned from a horizontal arrangement to a vertical arrangement at the bottom of the axle beam. This dimensional change allows the motor to generate large torque vertically while freeing up horizontal space, thereby increasing the distance between drive motor end faces and expanding the bus aisle width for improved passenger comfort.

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

Solution Approach 2:

The patent adopts an asymmetric vertical arrangement where the drive motor assembly is positioned at the bottom rather than symmetrically at the ends. This asymmetric configuration optimizes space utilization and maximizes the aisle width while maintaining the required power output.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP3978283B1Sunken wheel-side motor drive axle
Publication Date: 2025.01.01 JING JIN ELECTRIC TECH CO LTD
  • EP3978283B1 patent drawingFigure 1~2

AI summary

A sunken wheel-side motor drive axle is disclosed. The sunken wheel-side motor drive axle comprises an axle beam assembly (8), and further comprises two drive motor assemblies, two reducer assemblies and two hub assemblies, and the two drive motor assemblies, two reducer assemblies and two hub assemblies are respectively disposed at left and right ends of the axle beam assembly (8); the drive motor assemblies are symmetrically disposed at a bottom of the left and right ends of the axle beam assembly (8) respectively; and the drive motor assemblies transmit power to the reducer assemblies, and the reducer assemblies drive the hub assemblies to rotate. In the wheel-side electric drive axle, the drive motors are disposed at the bottom of the axle beam assembly (8), thereby reducing the occupied space, increasing the aisle width of new energy commercial bus, and improving the comfort of passengers; moreover, the transmission speed ratio is increased through the three-stage speed reducing transmission, thereby reducing the requirement for the output torque of the drive motor while ensuring the same wheel end drive torque, and also effectively reducing the size of the drive motor.