Rotating Electric Machine Oil Passage Segmentation

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Solution Overview

Problem

Conventional rotating electric machines face a tradeoff between improving rotor core cooling and reducing drag loss in the multiple disc clutch, as excessive oil supply for cooling increases drag loss.

Innovation Solution

The design incorporates a first oil passage that passes through the multiple disc clutch to reach the rotor core, and a second oil passage that bypasses the clutch to directly reach the rotor core, allowing for independent optimization of oil supply for both components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If operating oil is supplied to cool the rotor core, then cooling performance is improved, but drag loss of the clutch increases

Engineering Contradiction:

Improverotor core temperatureVSAvoiddrag loss of clutch

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

The oil passage system is segmented into multiple independent passages: a first oil passage that supplies oil to the clutch, a second oil passage that supplies oil to the rotor core without passing through the clutch, and a third oil passage that supplies oil to both the clutch and rotor core. This segmentation allows independent control of oil flow to each component, enabling the rotor core to be cooled without unnecessarily increasing drag loss in the clutch.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different oil supply paths are provided for different components based on their specific needs. The second oil passage provides dedicated cooling oil flow to the rotor core area, while the first oil passage provides lubrication oil to the clutch. This local differentiation ensures that cooling requirements of the rotor core are met without forcing excessive oil through the clutch, thereby reducing unnecessary drag loss.

Inventive Principle:

Principle #3Local quality

2Temperature

If operating oil flowing amount for cooling rotor core is increased, then cooling performance is improved, but oil supply amount becomes excessive for clutch lubrication

Engineering Contradiction:

Improverotor core coolingVSAvoidoperating oil supply amount

Core Design Contradiction:

TemperatureVSQuantity of substance

Solution Approach 1:

The oil supply system is divided into separate passages that can independently control oil flow quantities. The second oil passage is dedicated to rotor core cooling and can supply the necessary oil quantity without affecting the clutch lubrication oil supply in the first passage. This allows precise control of oil quantity for each component.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The third oil passage acts as an intermediary that can distribute oil to both the clutch and rotor core, allowing flexible allocation of oil quantity. By using this intermediate passage, the system can optimize the distribution of oil quantity to meet both lubrication and cooling requirements without waste.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 configuration enhances cooling performance for the rotor core while minimizing drag loss in the clutch by optimizing oil distribution, thereby improving overall machine efficiency.

Implementation Method 1

a rotor core and a first shaft. The rotor core faces an inner side of the stator in a radial direction with respect to the rotation center and includes a permanent magnet provided such that electromagnetic force acts between the permanent magnet and the coil

Methodology Applied

Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

operating oil (oil) flowing from an inner side towards an outer side in the radial direction lubricates and cools the multiple disc clutch

Methodology Applied

Scientific EffectLubrication: Lubrication

Implementation Method 3

operating oil (oil) flowing from an inner side towards an outer side in the radial direction lubricates and cools the multiple disc clutch, and then cools the rotor core

Methodology Applied

Scientific EffectConvection cooling: Convection

Data Source

PatentUS10944310B2Rotating electric machine

Publication Date: 2021.03.09 TOYOTA JIDOSHA KK

AI summary

A rotating electric machine includes a case, a stator, a first rotary member including a rotor core and a first shaft, a second rotary member including a second shaft, and a multiple disc clutch. A first oil passage and a second oil passage are provided inside the case. The first oil passage starts from an inside of the first shaft or an inside of the second shaft, passes through the multiple disc clutch from an inner side to an outer side in a radial direction with respect to a rotation center, and reaches an inner side of the rotor core in the radial direction. The second oil passage starts from the inside of the first shaft or the inside of the second shaft and reaches the inner side of the rotor core in the radial direction without passing through the multiple disc clutch.