Electric Motor Sensor Receptacle Design

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Solution Overview

Problem

Existing electric motors with Hall-effect sensors installed in additional recesses are bulky, costly, and inefficient due to mechanical stresses from welding operations, which compromise junction efficiency and lead to potential damage from vibrations.

Innovation Solution

The electric motor design incorporates a Hall-effect sensor and connections within a receptacle that can be inserted into a complementary seat in the cover, avoiding mechanical stresses and eliminating the need for a printed circuit, using molded plastic components and connectors to ensure secure and insulated electrical connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the Hall-effect sensor is installed in additional recesses, then the sensor can detect rotor rotation, but the motor dimensions increase and heavier magnets are required

Engineering Contradiction:

Improverotation rate detectionVSAvoidmotor dimensions

Core Design Contradiction:

Measurement precisionVSVolume of moving object

Solution Approach 1:

The sensor, its connections, and mounting structure are merged into a single integrated sensor assembly that fits within the existing cover space. This consolidation eliminates the need for additional recesses while maintaining rotation detection functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The cover structure serves multiple functions: it houses the brushes, provides mounting for the sensor assembly, and maintains motor sealing. The sensor assembly itself integrates the sensor element, electrical connections, and mechanical mounting, reducing overall motor complexity and dimensions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If welding operations are used to fit sensor connections and power supply lines, then electrical connections are established, but mechanical stresses compromise junction efficiency and reliability

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidjunction strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The welding process is replaced with a mechanical insertion system. The sensor assembly with pre-attached connections is inserted into a complementarily shaped seat in the cover, establishing electrical connections through direct mechanical contact without thermal or mechanical stress from welding operations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The sensor system is segmented into a separate assembly that includes the sensor element, connections, and mounting features. This allows the sensor assembly to be manufactured and tested independently, then installed as a complete unit without welding, reducing stress on junctions.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If a rigid printed circuit is used to interface sensor connections, then electrical interfacing is achieved, but mechanical stresses from assembly and vibrations can damage junctions and cause loss of electrical continuity

Engineering Contradiction:

Improveelectrical interfacing capabilityVSAvoidelectrical continuity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The rigid printed circuit board is replaced with a flexible cable assembly that provides electrical interfacing. The flexible cable can accommodate mechanical stresses from assembly and vibrations without damaging junctions or losing electrical continuity, while still providing the necessary electrical connections.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

A flexible cable assembly is used instead of a rigid printed circuit board. The flexibility of the cable allows it to absorb mechanical stresses during assembly and operation, preventing damage to electrical junctions and maintaining continuous electrical connectivity in vibrating environments.

Inventive Principle:

Principle #30Flexible shells and thin films

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 results in a compact, cost-effective, and reliable electric motor with improved mechanical stress resistance, enhanced electrical insulation, and reduced risk of short circuits, suitable for various applications without increasing motor size or weight.

Implementation Method 1

The Hall-effect sensor is suitable to detect the passage in front of it of the poles of a magnet that is rigidly coupled to the motor shaft

Methodology Applied

Scientific EffectHall-effect: Hall Effect

Data Source

PatentUS7705498B2Electric motor

Publication Date: 2010.04.27 NUOVA SME

AI summary

An electric motor, comprising a shell for a rotor, which is closed by a cover provided with a hole for the passage of a motor shaft; the cover accommodates and supports sliding contact brushes for a commutator for supplying power to the rotor, a sensor for detecting the rotation rate of the rotor, and connections for signal transmission and power supply of the sensor. The sensor and its connections for the transmission of its signals and for supplying it with power are accommodated in a receptacle, which in turn is then inserted in a complementarily shaped seat in the cover.