Coaxial Wheel Drive Module Without Intermediate Gears

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Solution Overview

Problem

Existing wheel drive modules suffer from low efficiency, noise, and high wear due to complex mechanical interactions and intermediate gears between electric motors and sprockets.

Innovation Solution

A wheel drive module with coaxially arranged annular gear rims and electric motors, where the rotors are directly connected to the gear rims, eliminating intermediate gears and reducing mechanical components, allowing for efficient and quiet operation by superimposing rotations to drive and steer the wheel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If intermediate gears and mechanical transmission components are used between electric motors and gear rings, then the wheel drive module can achieve wheel steering and driving functions, but the efficiency is low and mechanical wear is high

Engineering Contradiction:
ImproveefficiencyVSAvoidmechanical transmission components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes intermediate gears and mechanical transmission components from the system. The electric motors directly drive the gear rings, eliminating the need for complex intermediate transmission mechanisms. This extraction of unnecessary components directly improves efficiency and reduces mechanical wear.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the traditional mechanical transmission system with a more efficient configuration where electric motors directly couple to the gear rings. This substitution eliminates the mechanical losses associated with intermediate gears and reduces the overall mechanical complexity of the drive module.

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

2Ease of operation

If multiple intermediate gears and mechanical components are used for transmission, then the wheel can be steered and driven, but the noise level is high

Engineering Contradiction:
Improvewheel steering and driving functionVSAvoidnoise
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes the noisy intermediate gears and mechanical transmission components from the system. By having electric motors directly drive the gear rings, the source of mechanical noise is eliminated while the essential wheel steering and driving functions are preserved.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If complex mechanical interactions with multiple components are used, then the wheel drive module can perform steering and driving, but the mechanical wear is significant

Engineering Contradiction:
Improvesteering and driving capabilityVSAvoidmechanical wear
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent removes the wear-prone intermediate gears and mechanical transmission components from the system. The direct connection between electric motors and gear rings eliminates the mechanical contact and friction that cause wear, thereby improving reliability while maintaining full steering and driving capability.

Inventive Principle:
Principle #2Taking out (Extraction)

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

The solution enhances efficiency, reduces noise, and minimizes wear by direct motor-to-gear rim connections, achieving effective wheel drive and steering with reduced mechanical complexity.

Implementation Method 1

The first electric motor (31) for driving the first gear ring (11) has a first annular rotor (13) which is fixed in a fixed position on the first gear ring (11) so as to rotate around the axis of rotation (R). Furthermore, the second electric motor (32) for driving the second gear ring (12) has a second annular rotor (14) which is fixed in a fixed position on the second gear ring (12) around the rotation axis (R).

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4119378B1Wheel drive module for steering and driving a wheel
Publication Date: 2024.02.21 EBM PAPST ST GEORGEN GMBH & CO KG
  • EP4119378B1 patent drawingFigure 1~2

AI summary

The invention relates to a wheel drive module (1) for steering and driving a wheel (2) with a gearbox, a first electric motor and a second electric motor, wherein the gearbox has a pinion shaft (10) as well as a first annular gear ring (11) and a second annular gear ring (12), wherein the first gear ring (11) and the second gear ring (12) are arranged coaxially to each other rotatably about a common axis of rotation (R), wherein the pinion shaft (10) is rotatable by a respective rotation of the first gear ring (11) and the second gear ring (12) about the axis of rotation (R) as the steering axis of the wheel (2) and is rotatable about a pinion shaft axis (A) of the pinion shaft (10), so that the wheel (2) connectable to the pinion shaft (10) is steerable about the steering axis and, by a rotation of the pinion shaft (10) about the pinion shaft axis (A), about a wheel axis of the wheel (2). is propellablewherein the first electric motor for driving the first gear ring (11) has a first ring-shaped rotor (13) which is fixed around its axis of rotation (R) in a positionally fixed position on the first gear ring (11) and the second electric motor for driving the second gear ring (12) has a second ring-shaped rotor (14) which is fixed around its axis of rotation (R) in a positionally fixed position on the second gear ring (12).