Segment-Core Stator Assembly for Inner-Rotor Motor Manufacturing

Solution Overview

Problem

The challenge lies in manufacturing a segment-core type stator for inner-rotor type rotary electric machines that balances the difficulty of assembling a cage stator coil with a large diameter into a stator core while maintaining mechanical rigidity and reducing magnetic resistance, which is complicated by the number of divisions in the stator core.

Innovation Solution

The solution involves a segment-core type stator configuration where the central side segment core has a larger circumferential scale than the end side segment core, with fewer divisions in the central core, allowing for easier fitting and enhanced rigidity, and a method of manufacturing that includes compressing the stator coil to facilitate insertion into slots with fewer divisions, thereby reducing magnetic resistance and simplifying the assembly process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the stator core is divided into many segments to facilitate assembly of the cage stator coil, then the ease of manufacture is improved, but the mechanical rigidity deteriorates

Engineering Contradiction:

Improveease of assemblyVSAvoidmechanical rigidity

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The stator core is divided into a plurality of segment cores arranged circumferentially, with each segment core having slots for accommodating coil portions. This segmentation allows the cage stator coil to be assembled by inserting coil portions into corresponding slots of individual segment cores, which can then be joined together to form the complete stator core, thereby facilitating the assembly process while maintaining structural integrity through proper segmentation design

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cage stator coil is inserted into the segmented stator core structure, where the coil portions are nested within the slots of each segment core. The segment cores are then joined together to enclose and support the coil, creating a nested assembly structure that facilitates manufacturing while maintaining mechanical rigidity

Inventive Principle:

Principle #7Nested doll (Nesting)

2Ease of manufacture

If the stator core is divided into many segments to facilitate assembly, then the ease of manufacture is improved, but the magnetic resistance increases

Engineering Contradiction:

Improveease of assemblyVSAvoidmagnetic resistance

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The stator core is divided into a plurality of segment cores arranged circumferentially, with each segment core having slots for accommodating coil portions. This segmentation allows the cage stator coil to be assembled by inserting coil portions into corresponding slots of individual segment cores, which can then be joined together to form the complete stator core, thereby facilitating the assembly process while maintaining structural integrity through proper segmentation design

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The segment cores are designed with uniform magnetic properties and are arranged symmetrically around the rotor, ensuring homogeneous magnetic flux distribution. The junctions between segment cores are carefully designed to minimize magnetic resistance, maintaining uniform magnetic characteristics across the entire stator core structure

Inventive Principle:

Principle #33Homogeneity

3Power

If a large-size flat conductor wire is used to improve the slot space factor, then the output per unit weight is improved, but the difficulty of winding increases

Engineering Contradiction:

Improveoutput per unit weightVSAvoiddifficulty of winding

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The stator core is divided into a plurality of segment cores arranged circumferentially, with each segment core having slots for accommodating coil portions. This segmentation allows the cage stator coil to be assembled by inserting coil portions into corresponding slots of individual segment cores, which can then be joined together to form the complete stator core, thereby facilitating the assembly process while maintaining structural integrity through proper segmentation design

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention changes the winding approach from traditional continuous winding to a segmented insertion method. Large-size flat conductor wires are cut into appropriate lengths and inserted directly into the slots of segment cores, avoiding the complexity of winding large flat wires around the entire stator. This parameter change in the manufacturing process enables the use of large conductors while reducing winding difficulty

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8159105B2Segment-core type stator for inner-rotor type rotary electric machines and an improved method for manufacturing the stator

Publication Date: 2012.04.17 DENSO CORP

AI summary

When accommodating a cage stator coil in a stator core made up of distributed cores, an end side distributed core composing end side core at an end side in axial direction is made larger than a central side distributed core composing central side core. The cage stator coil is formed by compressing a central portion of an original cage stator coil. The end side segment core composing the end core is set at a central portion in an axial direction of the cage stator coil then the end side coil is moved to an end portion in the axial direction. The central side segment core composing the central core is set at the central portion in the axial direction of the cage stator coil thereafter.