Shaftless Pump Gear Integration for Compact Electric Oil Pumps

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Solution Overview

Problem

Conventional electric oil pumps (EOP) have a complex structure with multiple parts, leading to increased size and manufacturing costs, as well as potential damage during assembly.

Innovation Solution

The pump design eliminates the need for a rotation shaft by integrating a stator, pump gear, and magnet within a housing, where the magnet is mounted on an external gear with a specific curvature and groove design, reducing the number of parts and enhancing rotational efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional EOP structure with separate motor and pump regions is used, then the pump can function properly, but the number of parts increases and the overall size increases

Engineering Contradiction:
Improvepump functionVSAvoidnumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The motor region and pump region are merged into a single integrated structure where the motor stator serves as the pump housing and the motor rotor and pump gears share the same space. This merging eliminates the need for separate housings and reduces the number of parts while maintaining both motor and pump functions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The motor stator is designed to serve dual functions: as the stationary component of the motor and as the housing for the pump chamber. The motor rotor and pump inner rotor are integrated, allowing the same rotating assembly to perform both motor rotation and pump gear functions.

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

2Reliability

If a conventional EOP structure with separate motor and pump regions is used, then the pump can function properly, but the overall size increases in the axial direction

Engineering Contradiction:
Improvepump functionVSAvoidaxial length
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The design transitions from a stacked axial arrangement to a radial arrangement where the pump chamber is formed within the motor stator's radial space. The pump gears rotate radially within the motor rotor, utilizing the radial dimension rather than extending axially, thereby reducing the overall axial length.

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

3Volume of moving object

If an integrated pump-integrated structure is used, then volume and weight are reduced, but damage to the pump may occur during motor assembly

Engineering Contradiction:
Improvepump volumeVSAvoidpump damage risk
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The pump is divided into separable components (pump gears, seal, etc.) that can be assembled into the motor stator housing after the motor assembly is complete. This segmentation allows the pump components to be installed separately, avoiding damage during motor assembly while maintaining the compact integrated structure.

Inventive Principle:
Principle #1Segmentation

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

This design reduces the number of parts, lowers manufacturing costs, enables miniaturization, prevents fluid leakage, and reduces noise by housing the gears in the innermost space of the housing.

Implementation Method 1

a magnet disposed on the external gear

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 2

the stator, a pump gear disposed to correspond to the stator

Methodology Applied
Scientific EffectElectromagnetic interaction: Electromagnetic Induction

Data Source

PatentEP4063655B1pump
Publication Date: 2025.02.19 LG INNOTEK CO LTD
  • EP4063655B1 patent drawingFigure 1
  • EP4063655B1 patent drawingFigure 2
  • EP4063655B1 patent drawingFigure 3

AI summary

A pump comprises: a housing: a stator disposed inside the housing; a pump gear which is disposed to correspond to the stator and which includes an external gear and an internal gear; and a magnet disposed on the external gear, wherein the magnet includes a first outer circumferential surface , the external gear includes a second outer circumferential surface , and the curvature of the first outer circumferential surface can be smaller than the curvature of the second outer circumferential surface.