Motor Radial Dimension Reduction via Insulator Wire Nesting

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Solution Overview

Problem

In motor design, the radial dimension is increased due to interference between connecting wires and lead-out wires, which complicates the winding process and hinders space-saving and weight reduction efforts.

Innovation Solution

The motor design incorporates a stator with a magnetic core and insulator featuring teeth and wall portions, where connecting wires of later-wound phases pass through the inside of the wall portion of previously wound wires, avoiding radial overlap and protrusion, thus reducing the motor's radial dimension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If connecting wires are disposed to extend along the radially outer surface of the insulator, then the winding process is simplified, but the radial dimension of the motor increases due to wire interference and protrusion

Engineering Contradiction:
Improvewinding processVSAvoidradial dimension
Core Design Contradiction:
Ease of manufactureVSLength of stationary object

Solution Approach 1:

The patent transitions the wire routing from a two-dimensional path along the radially outer surface to a three-dimensional path that passes through the interior of the insulator. The insulator is designed with through-holes that guide connecting wires from one winding wire portion to another, allowing wires to traverse through the insulator's interior volume rather than extending along its outer surface, thereby reducing radial protrusion.

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

Solution Approach 2:

The connecting wires are nested within the insulator structure by passing through its interior. The insulator acts as a container that houses and guides the connecting wires, embedding them within its body rather than allowing them to extend externally. This nesting approach eliminates radial interference between adjacent phase wires.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Volume of moving object

If conducting wires are compactly wound to reduce motor size, then space saving is achieved, but wire interference between phases occurs increasing radial dimension

Engineering Contradiction:
Improvemotor sizeVSAvoidradial dimension
Core Design Contradiction:
Volume of moving objectVSLength of stationary object

Solution Approach 1:

The patent utilizes the axial and radial dimensions of the insulator to route connecting wires through its interior, effectively using the third dimension (depth/length of insulator) to resolve the two-dimensional wire layout problem. This allows compact winding while preventing radial wire interference.

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

3Reliability

If lead-out wires extend axially upward from winding wire portions, then electrical connection is achieved, but interference with connecting wires of subsequently wound phases occurs

Engineering Contradiction:
Improveelectrical connectionVSAvoidwire routing
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The insulator is segmented with individual through-holes for each phase's connecting wire, allowing independent routing of each phase's wires through dedicated pathways. This segmentation prevents interference between phases while maintaining reliable electrical connections for each phase separately.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2940834B1motor
Publication Date: 2019.08.21 NIDEC CORP(JP)
  • EP2940834B1 patent drawingFigure 1
  • EP2940834B1 patent drawingFigure 2
  • EP2940834B1 patent drawingFigure 3

AI summary

A motor has first, second, and third conducting wires (W1A, W2A, W3A) through which electric currents of the respective phases of a three-phase alternating current flow. Each of the first, second, and third conducting wires (W1A, W2A, W3A) includes a plurality of winding wire portions (61A), a connecting wire portion (62A), and a lead-out wire portion ( 63A). Each of the connecting wire portions (62A) of the second and third conducting wires (W2A, W3A) has an outer connecting wire portion (621A) passing through the outside in a radial direction of a wall portion (522A) of an insulator (52A), and an inner connecting wire portion (622A) passing through the inside in the radial direction of the wall portion (522A). The inner connecting wire portion (622A) of the second conducting wire (W2A) passes through the inside in the radial direction of the lead-out wire portion (63A) of the first conducting wire (W1A). The inner connecting wire portion (622A) of the third conducting wire (W3A) passes through the inside in the radial direction of the lead-out wire portion (63A) of the first conducting wire (W1A) and the lead-out wire portion (63A) of the second conducting wire (W2A). In this way, the interference of the connecting wire portion (62A) with the lead-out wire portions (63A) of other conducting wires (W1A, W2A, W3A) can be avoided. For this reason, the connecting wire portion (62A) and the lead-out wire portion (63A) do not radially overlap further on the outside in the radial direction than the wall portion (522A). In this way, it is possible to reduce the radial dimension of the motor.