Segment Coil Shoulder Press Marks for Easier Stator Insertion
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Solution Overview
Problem
Variations in the size of the pitch between respective open ends of the slot insertion parts of the segment coil lead to increased contact with the stator core and insulation paper, causing insertion difficulties and performance drops in electric motors.
Innovation Solution
A stator design and manufacturing method that incorporates segment coils with U-shaped configurations and press marks on the shoulder parts, adjusted using a press mark forming device to maintain precise angles and reduce pitch variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the stack thickness of the stator core is increased to allow high-speed rotation, then the motor can achieve higher power output, but the length of slot insertion parts must be increased, leading to increased variations in pitch between open ends
Solution Approach 1:
The patent applies preliminary action by pre-forming press marks on the shoulder parts of segment coils during the coil manufacturing process, before insertion into the stator core. This advance preparation ensures that the pitch between open ends is controlled within a predetermined range, preventing contact with the stator core even when slot insertion parts are lengthened to match increased stack thickness for high-power applications.
2Ease of manufacture
If the pitch between open ends of slot insertion parts varies, then the segment coils can be formed with standard tolerances, but the slot insertion parts come in contact with the stator core and insulation paper, causing insertion difficulties
Solution Approach 1:
The patent applies preliminary action by pre-forming press marks on the shoulder parts during coil manufacturing, which predetermined the pitch between open ends within a controlled range. This ensures that when the coils are later inserted into the stator core, the slot insertion parts maintain proper clearance and do not contact the stator core or insulation paper, eliminating insertion difficulties while allowing standard tolerance formation.
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 solution effectively suppresses variations in the angle of the shoulder part, improving the ease of segment coil insertion into the stator core and enhancing the efficiency and performance of the electric motor.
Implementation Method 1
a press mark forming device that forms press marks on the shoulder parts of the segment coil... applying a load to the holding plates to form the press marks
Data Source
AI summary
An object of the present invention is to suppress variations in an angle of a shoulder part of a segment coil to improve easiness in inserting segment coils in a stator core.A stator of an electric motor according to the present invention includes a stator core 12 in which a plurality of slots 12a are formed, and a plurality of segment coils 11 of U shapes inserted respectively in the plurality of slots 12a. The segment coil 11 includes a shoulder part 11a and a shoulder part 11b that are bent to form a U shape. In a front view of the U shape, a press mark 100a is formed on the shoulder part 11a and on the shoulder part 11b, the press mark being a dent sinking in a front-to-rear direction, from a front surface of the shoulder part 11a and from a front surface of the shoulder part 11b. The press mark 100a is formed also on a back surface of the shoulder part 11a and on a back surface of the shoulder part 11b.