Magnetic Torque Sensor Staking Fixing Ring Displacement

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Solution Overview

Problem

The existing torque sensors face challenges in securely fixing the magnetic collecting ring in the annular groove without compromising the magnetic flux collecting performance, due to fitting clearance and internal stress generated by press-fitting.

Innovation Solution

A torque sensor design that includes a staking part on the housing's inner peripheral surface to firmly fix the magnetic collecting ring into the annular groove, preventing radial and circumferential displacement and minimizing stress, thus maintaining the magnetic flux collecting performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the magnetic collecting ring is fitted into the annular groove with fitting clearance, then the magnetic collecting ring can be installed into the housing, but the magnetic collecting ring cannot be secured firmly and may displace radially or circumferentially

Engineering Contradiction:
Improveinstallation of magnetic collecting ringVSAvoidposition stability of magnetic collecting ring
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The housing's annular groove is divided into a fitting portion for receiving the magnetic collecting ring and a staking portion for forming restraining protrusions. This segmentation allows the groove to serve dual functions: enabling easy installation through the fitting clearance while preventing displacement through the staking portion that creates mechanical interlocking features.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The staking part is formed on the inner peripheral surface of the housing in advance, before the magnetic collecting ring is installed. This preliminary action creates the restraining protrusions that will later engage with the magnetic collecting ring, ensuring that once installed, the ring is firmly secured against radial and circumferential displacement.

Inventive Principle:
Principle #10Preliminary action

2Stability of the object's composition

If the magnetic collecting ring is press-fitted into the annular groove, then the magnetic collecting ring can be secured firmly, but internal stress is generated that deteriorates the magnetic flux collecting performance

Engineering Contradiction:
Improveposition stability of magnetic collecting ringVSAvoidmagnetic flux collecting performance
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The annular groove is segmented into a fitting portion with larger clearance that allows easy installation without excessive force, and a staking portion that provides mechanical restraint. This eliminates the need for press-fitting while still achieving firm security, thereby preventing internal stress generation that would harm magnetic flux collection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The staking part acts as an intermediary mechanism between the housing and the magnetic collecting ring. Instead of directly press-fitting the ring into the groove (which causes stress), the staking part creates restraining protrusions that gently engage with the ring, providing secure fixation without the harmful internal stresses of traditional press-fitting.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If fitting clearance is provided between the magnetic collecting ring and the annular groove, then the magnetic collecting ring can be installed, but the magnetic collecting ring is difficult to secure firmly without causing displacement

Engineering Contradiction:
Improveinstallation processVSAvoidfixation reliability
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The annular groove is divided into two functional zones: the fitting portion that accommodates the magnetic collecting ring with appropriate clearance for easy installation, and the staking portion that forms mechanical interlocks to prevent displacement. This segmentation resolves the contradiction by providing both installation ease and fixation reliability through different structural regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The traditional press-fitting mechanical system is replaced with a staking-based mechanical interlocking system. The staking part forms protrusions that engage with recesses or features on the magnetic collecting ring, providing secure fixation without the need for forceful press-fitting, thus maintaining both ease of installation and fixation reliability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

The staking process securely fixes the magnetic collecting rings without deteriorating the magnetic flux collecting performance, ensuring accurate torque detection in the torque sensor.

Implementation Method 1

a magnetic force generating part which rotates together with an end of the torsion bar while generating a magnetic flux in a direction of the rotation axis

Methodology Applied
Scientific EffectMagnetic flux generation: Electromagnetic Induction

Implementation Method 2

The rotating magnetic circuit transmits the magnetic flux generated by the magnetic force generating part to the magnetic collecting ring in accordance with a relative rotation positions of the magnetic force generating part and the rotating magnetic circuit

Methodology Applied
Scientific EffectMagnetic flux transmission: Magnetic Field

Implementation Method 3

a magnetic sensor which detects a magnetic flux density in the magnetic collecting ring

Methodology Applied
Scientific EffectMagnetic flux density detection: Hall Effect

Data Source

PatentEP2107354B1Magnetic torque sensor and manufacturing method thereof
Publication Date: 2015.08.26 KYB CORP
  • EP2107354B1 patent drawingFigure 1
  • EP2107354B1 patent drawingFigure 2
  • EP2107354B1 patent drawingFigure 3A~3B

AI summary

A torque sensor (50) comprises a magnetic collecting ring (91, 92) fitted into an annular groove (31, 32) formed on the inner periphery (38) of a housing (30). By providing a staking part (33, 34) on the inner periphery (38) of the housing (30) in the vicinity of the annular groove (31, 32) using a staking device (100), the magnetic collecting ring (91, 92) can be secured in the annular groove (31, 32) through a simple process.