Rotary Machine Power Distribution Unit with Axial Terminal Holes
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Solution Overview
Problem
Conventional power distribution units for rotary electric machines face challenges in securing sufficient insulation distances between adjacent phases, achieving reliable welding, and minimizing size and production costs due to complex construction and overlapping components.
Innovation Solution
A power distribution unit with connecting rings featuring linear conductors and terminal sections with holes and protrusions, arranged concentrically with insulating members, allowing for secure insulation and reduced size, using soldering or welding for connections, and minimizing the number of components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a through hole is formed in a connecting ring and the surface around it is pressed to form a planar part, then the through hole can be fabricated, but the connecting part extends in the radial direction making it difficult to secure sufficient insulation distance from adjacent connecting rings
Solution Approach 1:
The patent changes the orientation of the hole from radial to axial direction. Instead of forming a hole radially through the connecting ring (which requires planar pressing and extends radially), the hole is formed axially through the terminal section. This dimensional change allows the connecting part to extend in the axial direction rather than radial direction, thereby securing sufficient radial insulation distance from adjacent connecting rings while maintaining manufacturability.
2Ease of manufacture
If the surface of the connecting ring around the through hole is planar, then the through hole can be formed, but it becomes difficult to insert a coil terminal into the through hole
Solution Approach 1:
The patent changes the hole orientation from radial to axial direction. The axial hole through the terminal section provides a more accessible opening for coil terminal insertion compared to a radial hole that would require planar pressing. The axial orientation aligns with the natural insertion direction of coil terminals, significantly improving ease of operation while maintaining manufacturing capability.
3Reliability
If welding of the coil terminal to the connecting ring is attempted with a radial through hole, then connection can be achieved, but it is difficult to achieve acceptable heat balance between the coil terminal and connection ring since the volume of the molten part is much larger than the coil terminal
Solution Approach 1:
The patent changes the hole orientation from radial to axial direction, which fundamentally alters the welding geometry. The axial hole through the terminal section creates a more balanced weld joint where the coil terminal and terminal section have comparable volumes. This improves heat balance during welding, making the welding process easier to control and achieve reliable connections without excessive molten material.
4Reliability
If lead frames for multiple phases overlap as seen in the axial direction to form a power distribution unit, then connection with stator coil terminals can be established, but the space on the edge of the stator in the axial direction broadens increasing the size of the rotary electric machine
Solution Approach 1:
The patent merges multiple functions into a single terminal section structure. The terminal section integrates the connecting ring function, the insulating structure, and the connection interface for coil terminals into one compact axial element. This eliminates the need for multiple overlapping lead frames in the axial direction, thereby reducing the axial size of the power distribution unit while maintaining reliable coil terminal connections.
Solution Approach 2:
The patent transitions from a radial overlapping arrangement of lead frames to an axial stacking arrangement with terminal sections. By forming holes axially through terminal sections rather than radially through overlapping lead frames, the design reduces axial space requirements while achieving the same connection functionality.
5Reliability
If overlapping lead frames and partial fixing units are used to form connecting rings, then power distribution can be achieved, but many parts are necessary leading to an increase in production cost
Solution Approach 1:
The patent merges multiple separate components (lead frames, fixing units, insulating structures) into a single integrated terminal section. This reduction in part count directly lowers production costs while maintaining the power distribution functionality. The terminal section serves as both the connecting ring and the connection interface, eliminating the need for separate fixing units and overlapping lead frames.
Data Source
AI summary
The power distribution unit for a rotary electric machine includes a connecting ring unit that connects stator coils of the same phase. The connecting ring unit includes at least one linear conductor integrally formed in a ring-like shape, and the connecting ring unit includes a terminal section integrally formed in the linear conductor. The terminal section is constituted by a hole through which a wiring end of the stator coil is inserted and a protrusion formed in a direction of the hole to which the wiring end of the stator coil is connected. Also disclosed are a rotary electric machine includes the power distribution unit and a method for assembling a rotary electric machine.