Vehicle Wheel Bearing Cover with Bulging Sensor Bore Bottom

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Solution Overview

Problem

Conventional bearing devices for vehicle wheels suffer from deformation and damage to the mounting bore bottom when the magnetic sensor interferes, leading to reduced rotation speed detecting accuracy and potential ABS malfunction due to magnetic encoder interference.

Innovation Solution

The bearing device features a cover with a sensor mounting bore having a thin bottom that bulges inward, providing a thicker bulging portion to absorb interference forces, preventing deformation and maintaining accurate rotation speed detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the mounting bore bottom is made thin to reduce gap between magnetic sensor and magnetic encoder, then the gap is reduced improving detection precision, but the bottom becomes deformed and damaged due to magnetic sensor interference

Engineering Contradiction:

Improverotation speed detection precisionVSAvoidmounting bore bottom strength

Core Design Contradiction:

Measurement precisionVSStrength

Solution Approach 1:

The mounting bore bottom is segmented into two functional zones: a thin peripheral portion for minimizing gap and maximizing detection precision, and a thick central bulging portion for providing structural support and preventing deformation. This segmentation allows each zone to fulfill its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The bottom is pre-formed with a bulging shape before the magnetic sensor is installed. This preliminary action of creating the bulged structure ensures that when the magnetic sensor is later installed, the bulge is already in place to prevent deformation, rather than trying to correct deformation after it occurs.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If the mounting bore bottom is made thin to reduce gap, then detection precision is improved, but the bottom deforms toward the magnetic encoder causing interference

Engineering Contradiction:

Improverotation speed detection precisionVSAvoidmagnetic encoder interference

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The bottom is divided into a thin peripheral region that minimizes gap for better detection precision and a thick central bulging region that acts as a mechanical barrier preventing the bottom from deforming toward the magnetic encoder, thus eliminating interference.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The bulging portion of the bottom acts as an intermediary structural element between the magnetic sensor and the magnetic encoder. It provides mechanical support to prevent deformation that would otherwise cause interference, while maintaining the thin peripheral areas needed for precise detection.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If the mounting bore bottom is made thin to reduce gap, then detection precision is improved, but wear or damage allows muddy water to enter the bearing device

Engineering Contradiction:

Improverotation speed detection precisionVSAvoidbearing device reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The bottom structure is segmented with thin peripheral portions for detection precision and a thick reinforced central bulging portion that provides enhanced mechanical strength and wear resistance. This thicker central region acts as a protective barrier that prevents damage and blocks the entry of muddy water into the bearing device.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the bottom have different thickness qualities tailored to their specific functions: the peripheral regions are thin to minimize gap for precise detection, while the central region is thick and bulged to provide structural integrity, prevent wear, and block contaminants.

Inventive Principle:

Principle #3Local quality

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 effectively suppresses deformation of the mounting bore bottom, prevents damage, and avoids interference between the magnetic encoder and the bore, ensuring accurate rotation speed detection and preventing ABS malfunctions.

Implementation Method 1

The bearing device is configured to detect the rotation speed of the vehicle wheel connected to the wheel hub, based on an interval of change in magnetism at the time when the magnetic encoder that integrally rotates with the wheel hub passes by the magnetic sensor

Methodology Applied

Scientific EffectMagnetic field detection: Magnetic Field

Data Source

PatentUS10598226B2Bearing device for vehicle wheel

Publication Date: 2020.03.24 NTN CORP

AI summary

A bearing device (1) for a vehicle wheel is provided with: a magnetic encoder (7) provided to an inner-side end of an inner race (4), which is an inward member; a cover (11) for covering an inner-side opening (2B) of an outer race (2), which is an outward member, the cover having opened therein a sensor attachment hole (11H) in which an opening (11A) and a thin-walled bottom (11B) are formed; and a magnetic sensor (9) disposed facing the magnetic encoder across the bottom. The magnetic sensor is inserted into the sensor attachment hole in the cover through the opening (11A). The bottom (11B) in the sensor attachment hole is formed in such a shape as to bulge toward the inner side.