Pump Motor Fixed Bearing Segmentation for Noise Reduction

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Solution Overview

Problem

Existing pump motors with permanent magnet rotors face issues with uneven bearing contact and increased noise due to material thickness differences in bearing bushes, leading to deformation and irregularities during rotation, which cannot be fully mitigated by arbitrary tolerance adjustments.

Innovation Solution

A fixed bearing design comprising a press ring, a raceway, and an annular disk-shaped hub allows for uniform contact over the bearing length and compensates for small angular errors, with the hub's flexibility preventing deformation forces from reaching the raceway, and a thrust washer ensures optimal sliding properties under axial forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If bearing bushings with different material thicknesses are used, then the bearing can accommodate varying structural requirements, but the running surface deforms during pressing resulting in point or line contact and increased bearing noise

Engineering Contradiction:
Improvebearing structural adaptabilityVSAvoidbearing contact uniformity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The bearing bushing is divided into two functional segments: a press ring that absorbs deformation during pressing, and a running ring that maintains its optimal shape for uniform contact. This segmentation allows the bearing to accommodate structural variations while preserving contact uniformity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The press ring acts as an intermediary element between the external pressing forces and the running ring. It absorbs the deformation forces that would otherwise be transmitted to the running surface, protecting the contact interface from distortion.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If tight tolerances are applied to bearing bushings, then bearing contact uniformity can be improved, but manufacturing cost increases significantly

Engineering Contradiction:
Improvebearing contact uniformityVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

By segmenting the bearing into press ring and running ring, the need for tight tolerances on the entire bearing is eliminated. Only the running ring requires precise dimensions, while the press ring can be manufactured with more relaxed tolerances, reducing overall manufacturing cost.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The press ring is designed as a sacrificial element that can be manufactured economically with standard tolerances. It absorbs the deformation during assembly, protecting the more expensive running ring from damage and eliminating the need for expensive tight-tolerance manufacturing across the entire bearing.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Adaptability or versatility

If the press ring deforms during pressing, then it can accommodate manufacturing variations, but deformation forces are transmitted to the running ring causing noise

Engineering Contradiction:
Improvepressing process toleranceVSAvoidbearing noise
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The press ring serves as a mediator that intentionally deforms during pressing to absorb manufacturing variations, while its design prevents transmission of deformation forces to the running ring. The hub connects the two rings but is designed to isolate the running ring from press-induced deformations.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful deformation function is extracted from the running ring and assigned exclusively to the press ring. The running ring is taken out from the deformation process entirely, maintaining its optimal shape while the press ring handles all pressing-related deformations.

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

This design achieves reliable and cost-effective mounting of the permanent magnet rotor, reducing noise and ensuring smooth operation by maintaining the raceway's shape while allowing the hub to absorb deformation, thus providing a stable and quiet running pump motor.

Implementation Method 1

the hub's flexibility preventing deformation forces from reaching the raceway

Methodology Applied
Scientific EffectFlexibility: Elasticity

Implementation Method 2

a press ring pressed into the permanent magnet rotor

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

a raceway rotatably mounted on the shaft

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 4

a thrust washer ensures optimal sliding properties under axial forces

Methodology Applied
Scientific EffectSliding friction: Friction

Data Source

PatentEP3232065B1Pump motor with a fixed bearing
Publication Date: 2020.01.08 BUHLER MOTOR GMBH
  • EP3232065B1 patent drawingFigure 1
  • EP3232065B1 patent drawingFigure 2

AI summary

The invention relates to a pump motor (1) comprising a permanent magnet rotor (2), a containment shell (3), a wound stator (4), a motor housing (10), a pump head (11), a shaft (5) which is fixed in the containment shell (3) on one side and in the pump head (11) on the other, and a fixed bearing (6) which is pressed or injection-molded into the permanent magnet rotor (2) and rotatably supports the rotor on the shaft (5). The object of the invention is to provide, in a pump motor of this type, a reliable and economically producible bearing arrangement for the permanent magnet rotor on the shaft, whereby uniform contact of the bearing with the shaft is achieved over the entire bearing length and over a complete revolution, and small angular misalignments can be compensated for and noise can be reduced. This object is achieved according to the invention by the features of claim 1.