Rotating Electric Machine Front Bearing with Belt Tension Adjuster

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Solution Overview

Problem

Existing rotary electrical machines face challenges in integrating a belt tension adjustment device without increasing the size of the rear bearing, which can lead to mechanical interference and require complex assembly, compromising air circulation and electronic component compatibility.

Innovation Solution

A specific front bearing design with a forward-offset nose and flared zone for air inlet openings, allowing the belt tension adjustment device to be fixed to the casing while maintaining the rear bearing's size, and incorporating a device with tension rollers and central air passages to manage vibrations and air flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the belt tension adjustment device is integrated into the front bearing, then the device complexity is reduced, but the rear bearing size must be increased which causes mechanical interference

Engineering Contradiction:
Improveintegration complexityVSAvoidrear bearing size
Core Design Contradiction:
Device complexityVSVolume of moving object

Solution Approach 1:

The front bearing is segmented into distinct functional zones: a mounting zone for the belt tension adjustment device and a ventilation zone for air circulation. This segmentation allows the device to be integrated without increasing the rear bearing size, as the mounting nose and flared zone provide dedicated space for the adjustment mechanism while maintaining the original rear bearing dimensions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The front bearing structure extends in the axial direction with a forward-offset mounting nose and flared zone, utilizing the axial dimension to accommodate the belt tension adjustment device. This dimensional extension allows integration without increasing the radial size of the rear bearing, thereby avoiding mechanical interference with surrounding components.

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

2Device complexity

If the front bearing is modified to accommodate the adjustment device, then the device integration is simplified, but air circulation pathways are blocked

Engineering Contradiction:
Improveintegration simplicityVSAvoidair circulation blockage
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The front bearing exhibits local quality differentiation with distinct zones: a solid mounting nose and flared zone for device attachment, and strategically positioned air inlet openings and air outlet openings for ventilation. This local differentiation ensures that the belt tension adjustment device is accommodated while air circulation pathways remain unblocked, allowing cooling air to pass through the bearing structure.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If the rear bearing size is increased to accommodate the adjustment device, then the integration is easier, but mechanical interference with other components occurs

Engineering Contradiction:
Improveintegration easeVSAvoidcomponent compatibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The front bearing is segmented into distinct functional zones: a mounting zone for the belt tension adjustment device and a ventilation zone for air circulation. This segmentation allows the device to be integrated without increasing the rear bearing size, as the mounting nose and flared zone provide dedicated space for the adjustment mechanism while maintaining the original rear bearing dimensions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The front bearing structure extends in the axial direction with a forward-offset mounting nose and flared zone, utilizing the axial dimension to accommodate the belt tension adjustment device. This dimensional extension allows integration without increasing the radial size of the rear bearing, thereby avoiding mechanical interference with surrounding components.

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

4Reliability

If the belt tension adjustment device is added, then the belt tension control is improved, but the distance between bearings is reduced increasing vibration impact

Engineering Contradiction:
Improvebelt tension controlVSAvoidvibration impact on rear bearing
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The forward-offset mounting nose is designed to position the belt tension adjustment device as far forward as possible before the pulley. This preliminary positioning action maximizes the distance between the rear bearing and the belt-pulley interface, thereby reducing the transmission of axial and transverse vibrations to the rear bearing while maintaining effective belt tension control.

Inventive Principle:
Principle #10Preliminary action

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 increases the distance between the front and rear bearings, sparing the rear bearing from axial and transverse vibrations, ensures air passage for cooling, and allows the adjustment device to be integrated without altering the rotor or stator dimensions, thus maintaining the machine's mechanical and electronic integrity.

Implementation Method 1

said bearing comprising a base having a mounting nose for a ball bearing for rotation of the shaft and air inlet openings delimited by arms connecting the nose to a peripheral strip of material of the base

Methodology Applied
Scientific EffectAir flow:

Implementation Method 2

The forward offset of the nose relative to the material strip is a function of the central thickness of the adjustment device... increases the distance between the front and rear bearings, thus protecting the rear bearing despite axial and transverse vibrations transmitted by the belt

Methodology Applied
Scientific EffectVibration isolation: Damping

Implementation Method 3

said bearing comprising a base having a mounting nose for a ball bearing for rotation of the shaft

Methodology Applied
Scientific EffectBall bearing: Ball Bearing

Data Source

PatentEP3259834B1A rotating electric machine with drive belt, pulley and belt tension adjuster
Publication Date: 2021.09.08 VALEO EQUIP ELECTRIC MOTEUR
  • EP3259834B1 patent drawingFigure 1~2
  • EP3259834B1 patent drawingFigure 3
  • EP3259834B1 patent drawingFigure 4~5

AI summary

The rotary electrical machine comprises, in front, a pulley (3) secured to a shaft (9) of a rotor (20) passing through the front bearing (1a) of a housing. Said bearing includes a base, having a nose (18) for mounting a front ball bearing (7) for rotating the shaft (9), and air inlets (15) defined by arms belonging to an outwardly opening area connecting a peripheral strip of material from the base to the nose (18) in order to shift the nose (18) toward the front in accordance with the central body of a device (100) for adjusting the tension of a belt received in the groove (31) of the pulley (3) and attached onto the housing (1a, 1b). Said adjustment device (100) comprises at least one idler (200, 201) for tensioning the belt and a central opening (102) enabling passage of air through the air inlets (15).