Sensor Bearing Magnetic Target Alignment for Pitch Accuracy

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Solution Overview

Problem

The existing manufacturing methods for sensor bearing units result in a large concentricity defect in the groove of the inner ring, leading to degradation of the total pitch deviation of the magnetic target, which affects the measurement accuracy of the sensor bearing unit.

Innovation Solution

A method where the target holder is secured to the first ring, and the magnetic target is magnetized after securing, limiting the degradation of the total pitch deviation by ensuring accurate alignment and magnetization of the magnetic poles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the groove is soft turned and heat treatment is applied before magnetization, then the manufacturing process is simplified, but the concentricity defect increases leading to degradation of total pitch deviation

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidtotal pitch deviation

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The groove is machined with high precision before assembly, and the target holder is pre-aligned with the groove to ensure correct positioning. The magnetic target is then magnetized after assembly, preserving the precision of the groove while maintaining manufacturing efficiency.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If the magnetic target is magnetized before assembly, then the manufacturing sequence is simplified, but the alignment precision deteriorates due to subsequent assembly operations

Engineering Contradiction:

Improvemanufacturing sequence efficiencyVSAvoidalignment precision

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The groove and target holder are prepared in advance with precise dimensions and alignment features. The magnetic target is magnetized only after the target holder is securely assembled to the inner ring, ensuring that magnetization does not occur before final positioning is achieved.

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If the target holder is secured to the inner ring with a groove, then the assembly is simplified, but the concentricity defect degrades the total pitch deviation

Engineering Contradiction:

Improveassembly simplicityVSAvoidconcentricity

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The groove is machined with high precision before assembly to ensure correct concentricity with the inner ring bore. The target holder is designed with alignment features that ensure proper positioning in the groove before securing, maintaining concentricity while simplifying the assembly process.

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 method improves the measurement accuracy of the sensor bearing unit by reducing the total pitch deviation and ensuring precise alignment of the magnetic target, resulting in enhanced performance.

Implementation Method 1

b) magnetizing the magnetic material of the magnetic target after the step of securing the target holder to the first ring

Methodology Applied

Scientific EffectMagnetization: Magnetism

Data Source

PatentUS11629757B2Method for manufacturing a sensor bearing unit

Publication Date: 2023.04.18 AB SKF SKF PATENT DEPARTMENT

AI summary

The method provides for the manufacturing a sensor bearing unit including a bearing having a first ring and a second ring capable of rotating concentrically relative to one another, and an impulse ring provided with a target holder secured to the first ring and with a magnetic target mounted on the target holder. The method further includes securing the target holder to the first ring and magnetizing the magnetic material of the magnetic target after the step of securing the target holder to the first ring.