Motor Control Device Asymmetric Connector Layout

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Solution Overview

Problem

The existing motor control device experiences differences in length between current paths for three phases, leading to variations in electrical resistance and torque ripples due to the positional relationship between drive circuits and power supply terminal connectors, which affects the efficiency and performance of the motor.

Innovation Solution

The motor control device is designed with a board layout where the power supply terminal connector, inverter circuit, and motor terminal connector are arranged along the boundary line, with the motor terminal connector inclined to form an acute angle with the boundary line, reducing the bending of current paths and making them more linear, and the inverter circuit is positioned either inside or outside the motor terminal connector to minimize differences in current path lengths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the drive circuits and power supply terminal connectors are arranged with regularity on the board, then the layout is simplified and easier to manufacture, but the current path lengths for three phases may differ due to positional relationships

Engineering Contradiction:
Improveboard layout regularityVSAvoidcurrent path length uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The motor terminal connector is intentionally arranged asymmetrically relative to the boundary line, specifically rotated by 30 degrees so that its extending direction forms a 60-degree angle with the boundary line. This asymmetric arrangement compensates for the positional differences between drive circuits and power supply terminal connectors, equalizing the current path lengths for all three phases despite the regular board layout.

Inventive Principle:
Principle #4Asymmetry

2Device complexity

If the motor terminal connector is arranged parallel to the boundary line, then the layout is simplified, but the current paths bend more and length differences increase

Engineering Contradiction:
Improvelayout complexityVSAvoidcurrent path length difference
Core Design Contradiction:
Device complexityVSLength of stationary object

Solution Approach 1:

The motor terminal connector is rotated 30 degrees relative to the boundary line, creating an asymmetric arrangement where the connector's extending direction forms a 60-degree angle with the boundary line. This asymmetric positioning optimizes the current path geometry, reducing bending and equalizing path lengths for all three phases.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Instead of arranging the motor terminal connector purely parallel to the boundary line (one-dimensional alignment), the invention introduces angular orientation in a second dimension by rotating it 30 degrees. This dimensional change allows the current paths to follow more direct routes, reducing overall path length differences.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If the current paths are made more linear by adjusting the motor terminal connector angle, then electrical resistance decreases, but the layout becomes more complex

Engineering Contradiction:
Improveelectrical connection uniformityVSAvoidconnector arrangement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The motor terminal connector is positioned asymmetrically at a 30-degree rotation relative to the boundary line, creating optimal current path geometry. This single asymmetric adjustment simultaneously achieves linear current paths for all three phases, minimizing resistance variations without requiring multiple complex modifications to the layout.

Inventive Principle:
Principle #4Asymmetry

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 configuration reduces the difference in length among current paths, decreases electrical resistance, and minimizes torque ripples, enhancing the motor's efficiency and performance by ensuring more uniform current supply to the motor terminals.

Implementation Method 1

an inverter circuit that converts the DC power supplied from the power supply terminal connector to AC power of three phases

Methodology Applied
Scientific EffectInversion:

Data Source

PatentEP4047796A1Motor control device
Publication Date: 2022.08.24 JTEKT CORP
  • EP4047796A1 patent drawingFigure 1
  • EP4047796A1 patent drawingFigure 2
  • EP4047796A1 patent drawingFigure 3

AI summary

A motor control device (13) includes a board that is provided at an end of a motor (12) including winding groups of two systems and controls supply of electric power to the winding group independently for each system. The board includes two areas that are partitioned by a boundary line passing through the center of the motor (12) when viewed in an axial direction of the motor (12). A power supply terminal connector (55, 65), an inverter circuit (52, 62), and a motor terminal connector (54, 64) are sequentially arranged along the boundary line when viewed in the axial direction of the motor (12). The motor terminal connector (54, 64) is provided such that a straight line perpendicular to a direction in which motor terminals are arranged and the boundary line form an acute angle.