Spindle-Carrier Wheel Drive Assembly Noise Reduction

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Solution Overview

Problem

Current wheel drive systems for light, medium-speed vehicles face challenges with space constraints, noise, leaks, and poor efficiency, particularly in non-axle vehicles that rely on hydraulic motors.

Innovation Solution

A compact electric wheel drive assembly integrates a spindle-carrier that combines the functions of bearing support, wheel mounting, and torque multiplication, using an electric motor with an input sun gear, input planet gears, and output planet gears to reduce noise and length, replacing traditional hydraulic systems with a quiet and efficient electric motor and gearbox.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If traditional hydraulic motors are used to drive wheels in non-axle vehicles, then power transmission is achieved, but the system produces noise, leaks, and has poor efficiency

Engineering Contradiction:
Improveenergy efficiencyVSAvoidnoise and leaks
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the hydraulic motor system with an electric motor coupled to a planetary gear system. This substitution eliminates hydraulic fluid leaks and reduces noise while improving energy efficiency. The electric motor directly drives the input sun gear, which then transmits power through the planetary gears to the output carrier, achieving the same wheel drive function without hydraulic components.

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

Solution Approach 2:

The patent changes the fundamental operating parameters from hydraulic pressure-driven motion to electromagnetic rotation. By using an electric motor with controlled electrical parameters instead of hydraulic pressure, the system achieves cleaner operation, reduced noise, and improved efficiency while maintaining the required torque and speed output for vehicle propulsion.

Inventive Principle:
Principle #35Parameter changes

2Length of moving object

If separate spindle and carrier components are used in the wheel drive assembly, then bearing support and wheel mounting functions are provided, but the overall length and complexity of the gearbox increase

Engineering Contradiction:
Improvegearbox lengthVSAvoidnumber of separate components
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The patent merges the spindle and carrier into a single integrated component called the 'output carrier' or 'spindle-carrier'. This unified component performs both bearing support and wheel mounting functions simultaneously. The output carrier is supported by bearings on the fixed housing and extends outward to provide the wheel mounting interface, eliminating the need for a separate spindle component and reducing overall gearbox length.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The output carrier is designed as a multi-functional component that simultaneously serves as the bearing support structure, the rotational output shaft, and the wheel mounting interface. This universal component replaces what would traditionally require separate spindle and carrier parts, simplifying the overall assembly and reducing the number of parts needed in the differential mechanism.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2329983B1Wheel drive assembly and a spindle carrier
Publication Date: 2011.11.02 FAIRFIELD MFG CO INC
  • EP2329983B1 patent drawingFigure 1
  • EP2329983B1 patent drawingFigure 1A
  • EP2329983B1 patent drawingFigure 1B

AI summary

A wheel drive assembly includes a rotatable spindle-carrier affixed to a wheel. A fixed housing includes an output ring gear and the spindle-carrier resides generally within the housing. An output sun gear driven by an input carrier drives output planetary gears which, in turn, interengage the output ring gear driving and rotating the spindle-carrier. A fixed drive end housing includes an input ring gear and houses a noise reducing radially floating input carrier and a plurality of input planet gears rotatably mounted in the input carrier. The input sun gear is driven by an electric motor and drives the plurality of input planet gears which mesh with the input ring gear causing rotation of the input carrier about its true center. The input carrier is partially nested within the spindle-carrier and the motor is partially nested within the fixed drive end housing.