Rotor Cooling Air Rectification to Limit Shaft Size and Vibration

Solution Overview

Problem

The existing rotating electric machine systems face issues with increased rotor shaft size and vibrations due to the incorporation of fins within the rotor shaft, which are necessary for air cooling, leading to inefficiencies in cooling and stability at high speeds.

Innovation Solution

A rotating electric machine system with a rectifying structure comprising non-rotating fins that rectify the flow of cooling gas, supplied separately, to enhance cooling efficiency while minimizing the radial size of the rotor and reducing vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If fins are provided in the interior of the rotor to force air into the cooling passage, then cooling efficiency is improved, but the rotor shaft becomes large in scale in the radial direction and vibrations are generated at high rotation speeds

Engineering Contradiction:

Improvecooling efficiencyVSAvoidrotor shaft radial dimension

Core Design Contradiction:

TemperatureVSLength of moving object

Solution Approach 1:

The invention extracts the fins from the rotating rotor and relocates them to a stationary rectifying structure in the housing. This allows the cooling function to be maintained while eliminating the problem of large radial dimensions in the rotor shaft and vibrations at high rotation speeds.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a rectifying structure as an intermediary component between the air supply source and the rotor cooling passage. This rectifying structure with fins forces air into the cooling passage without requiring fins to be attached to the rotating rotor itself.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Temperature

If fins are provided in the interior of the rotor to force air into the cooling passage, then cooling efficiency is improved, but vibrations are generated when the rotor is rotated at high speed

Engineering Contradiction:

Improvecooling efficiencyVSAvoidvibrations

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The invention extracts the fins from the rotating rotor and relocates them to a stationary rectifying structure in the housing. This allows the cooling function to be maintained while eliminating the problem of large radial dimensions in the rotor shaft and vibrations at high rotation speeds.

Inventive Principle:

Principle #2Taking out (Extraction)

3Temperature

If the outer diameter of the fins is increased to draw air at a predetermined flow rate, then cooling efficiency is improved, but the rotor shaft becomes large in scale in the radial direction

Engineering Contradiction:

Improvecooling efficiencyVSAvoidrotor shaft radial dimension

Core Design Contradiction:

TemperatureVSLength of moving object

Solution Approach 1:

The invention extracts the fins from the rotating rotor and relocates them to a stationary rectifying structure in the housing. This allows the cooling function to be maintained while eliminating the problem of large radial dimensions in the rotor shaft and vibrations at high rotation speeds.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a rectifying structure as an intermediary component between the air supply source and the rotor cooling passage. This rectifying structure with fins forces air into the cooling passage without requiring fins to be attached to the rotating rotor itself.

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

The system effectively suppresses the increase in rotor shaft size and vibrations, ensuring smooth gas flow and efficient cooling without enlarging the rotor's radial dimensions.

Implementation Method 1

a rectifying structure including a plurality of fins configured to rectify flow of the gas

Methodology Applied

Scientific EffectFluid flow rectification:

Implementation Method 2

heat is exchanged between the heated rotor (the rotor shaft) and the air, and thereby the rotor is cooled

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

air passes through the plurality of fins, and is forcibly drawn into the air passage from the introduction opening portion. When the air flows along the air passage to the outlet opening portion, heat is exchanged

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentUS12603538B2Rotating electric machine system

Publication Date: 2026.04.14 HONDA MOTOR CO LTD

AI summary

A rotor of a rotating electric machine system is equipped with cooling passages and gas flow passages through which compressed air for cooling flows. The rotating electric machine system is equipped with a rectifying structure having a plurality of fins that are capable of rectifying the flow of the compressed air. The rectifying structure is fixed to a non-rotating portion inside a main housing. The rectifying structure faces toward the cooling passages and the gas flow passages.