Wheel Bearing Rotation Sensing With Switchable Pulse Resolution

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Solution Overview

Problem

Existing rotation detecting devices for vehicle wheels have insufficient resolving power, making them incompatible with standard ABS control devices, especially at high speeds, leading to processing delays and increased space, cost, and weight due to the need for both standard and high-resolution devices.

Innovation Solution

A rotation detecting device with an annular encoder and a sensor that uses a multiplying unit to generate pulses with multiple resolving powers, allowing selection of the appropriate power for processing by the ABS control device, regardless of its type, and integrating the sensor and multiplying unit on a common IC chip for compactness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a rotation detecting device with high resolving power is used, then measurement precision is improved, but device complexity increases and compatibility with standard ABS control devices deteriorates

Engineering Contradiction:
Improverotation detection resolving powerVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the output signal into multiple resolution levels (first resolution and second resolution) from a single sensor system. The multiplying unit generates high-resolution signals while the selecting unit provides low-resolution outputs, allowing the same device to serve both high-precision and standard ABS control applications without overload.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic resolution switching where the selecting unit can dynamically choose between first resolution and second resolution outputs based on the rotational speed conditions. This dynamic adaptation allows the device to provide high resolving power when needed while maintaining compatibility with standard ABS control devices under normal operating conditions.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If the input signal resolving power is increased to match high-resolution detection devices, then measurement precision is improved, but productivity of the ABS control device decreases due to processing delays at high speeds

Engineering Contradiction:
Improveinput signal resolving powerVSAvoidsignal processing speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The selecting unit dynamically adjusts the resolution level based on rotational speed conditions. At high speeds where processing capacity is constrained, it outputs lower-resolution signals that can be processed without delay. At lower speeds where processing capacity is sufficient, it outputs high-resolution signals for improved measurement precision, thus adapting to real-time processing demands.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the resolution parameter of the output signal based on operating conditions. By varying the resolving power parameter dynamically, the system optimizes the balance between measurement precision and processing speed, preventing processing delays while maintaining high precision when conditions allow.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If both standard and high-resolution rotation detecting devices are mounted, then adaptability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvecompatibility with different ABS control devicesVSAvoidnumber of sensors and processing units
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent creates a universal rotation detecting device that can output signals compatible with both standard ABS control devices and high-resolution detection systems. The single sensor system with multiplying unit and selecting unit performs multiple functions: generating high-resolution signals for advanced applications and low-resolution signals for standard ABS control, eliminating the need for separate devices.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent segments the signal processing functionality within a single device structure. The multiplying unit handles high-resolution signal generation while the selecting unit provides low-resolution outputs, allowing one physical device to replace what would traditionally require two separate devices, thus reducing overall system complexity.

Inventive Principle:
Principle #1Segmentation

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

Enables accurate rotation detection compatible with both standard and high-resolution ABS control devices, allowing for adaptive resolving power based on rotational speed, reducing processing delays and unnecessary complexity, while minimizing space and weight.

Implementation Method 1

a sensor for detecting the to-be-detected poles of the encoder

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Data Source

PatentEP3321640B1Rotation detecting device and bearing equipped with rotation detecting device
Publication Date: 2021.07.21 NTN CORP
  • EP3321640B1 patent drawingFigure 1
  • EP3321640B1 patent drawingFigure 2A~3B
  • EP3321640B1 patent drawingFigure 4A~4C

AI summary

A rotation detecting device provided in a bearing assembly comprising: an annular encoder provided rotatably and having a plurality of to-be-detected poles circumferentially equidistantly arranged therein; a sensor for detecting the to-be-detected poles of the encoder; a multiplying unit for multiplying a phase of the to-be-detected poles based on an output of the sensor; a pulse outputting unit adapted to receive an output of the multiplying unit or both an output of the multiplying unit and a detection output of the sensor and capable of outputting pulses of at least two types of magnifying powers that are different from each other; and a cap that covers an end face opening of an outer member of the bearing assembly. The device may output either ordinary pulses without passing them through the multiplying unit, or high resolution pulses after passing them through the multiplying unit. The cap comprises a cylindrical metal member having a plurality of slits, to form a series of separate mounting tabs.