Slotless Stator Coil Winding Methods and Structures
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Solution Overview
Problem
Conventional methods for forming stator coil windings for polyphase motors are complex and costly, lacking efficient and inexpensive solutions for creating effective field windings, particularly for slotless stators.
Innovation Solution
The development of novel coil winding topologies and methods involving the formation of coil windings on a flux return ring, with specific winding directions and interleaving patterns around a mandrel, allowing for the creation of a polyphase field winding with multiple coil groups that collapse into a single-layer web and wrap into a cylinder, enabling efficient electromagnetic field generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional methods for forming stator coil windings are used, then the field winding structure is achieved, but the manufacturing process is complex and costly
Solution Approach 1:
The coil windings are divided into multiple coil groups (first coil group, second coil group, third coil group) that can be independently formed and then assembled. Each coil group contains multiple coil windings that are wound around a mandrel in a systematic pattern, allowing modular manufacturing and simplifying the overall winding process while maintaining the required field winding structure.
Solution Approach 2:
The coil windings are pre-formed around a mandrel in a specific pattern before being collapsed and assembled into the final stator structure. This preliminary winding action on the mandrel establishes the correct geometric relationships and interleaving patterns between coil groups, reducing the complexity of final assembly and ensuring manufacturing precision.
2Ease of manufacture
If conventional coil winding methods are used, then the field winding is formed, but manufacturing costs are high
Solution Approach 1:
The coil windings are pre-formed around a mandrel with precise geometric relationships established during the winding process. The mandrel serves as a precision fixture that ensures correct spacing, orientation, and interleaving of coil groups before collapse and assembly, maintaining manufacturing precision while enabling more efficient production methods.
Solution Approach 2:
Multiple coil windings are nested around the mandrel in a compact arrangement, with each coil group containing multiple coils that are tightly packed. This nesting approach maximizes the use of space and material efficiency, reducing manufacturing costs while maintaining the required electromagnetic performance and geometric precision.
3Reliability
If coil windings are formed with specific interleaving patterns, then effective field winding is achieved, but the winding process becomes more complex
Solution Approach 1:
The field winding is segmented into multiple coil groups with distinct interleaving patterns. Each coil group is formed independently around the mandrel with a specific arrangement, and the groups are then assembled in a sequence that achieves the desired interleaving pattern. This segmentation makes the complex interleaving requirement more manageable and reliable.
Solution Approach 2:
The correct interleaving pattern is established during the preliminary winding process on the mandrel, rather than attempting to achieve it during final assembly. The mandrel geometry and winding sequence are designed to automatically produce the required interleaving relationships between coil groups, ensuring field winding effectiveness while simplifying the overall process.
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 approach simplifies the winding process, reduces costs, and effectively generates a polyphase field winding that drives the rotor with speed and torque dependent on applied electromotive force, suitable for both motors and generators, including small motors for sleep apnea treatment devices.
Implementation Method 1
Electromotive force, applied to the coil windings of the stator, drive the rotor at a speed and torque dependent on the power of the applied electromotive force
Data Source
AI summary
A method for making a poly-phase field winding for a slotless stator includes: forming the first coil group by winding an insulated wire for each coil winding in a first direction around a mandrel; axially shifting along the mandrel the insulated wire from a trailing edge of each coil winding a distance substantially equal to one half of twice the number of coil groups multiplied by the number of coil windings minus one times the width of one of the completed windings to position the wires at a leading edge of each of coil winding in the second coil group; forming the second coil group by winding the insulated wire for each coil winding in the first direction; removing the mandrel from the wound coil groups; collapsing the wound coil groups to a single layer web, and wrapping the single layer web into a cylinder to form the field winding.