Rotor Cage Injection Positioning Tool
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Solution Overview
Problem
The challenge in manufacturing rotary electric machine rotors is to securely hold bars in slots during aluminum injection without complicating the process or requiring precise machining, while allowing for design flexibility and ease of insertion.
Innovation Solution
A method where bars made of a first conducting material are held axially in slots by a positioning tool during aluminum injection, allowing for the use of as-extruded bars with clearance, eliminating the need for firm clamping and precision machining, and enabling the use of a simpler manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bars are firmly clamped in slots to prevent movement during injection, then bar retention is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The positioning tool is inserted into the cavity before aluminum injection to preliminarily position and hold the bars in the slots. This preliminary action prevents bar movement during injection without requiring permanent clamping arrangements, thereby maintaining reliability while reducing device complexity.
Solution Approach 2:
The positioning tool acts as an intermediary element between the bars and the injection process. It temporarily holds the bars in place during injection and is then removed, avoiding the need for complex permanent clamping mechanisms while ensuring reliable bar retention during the critical injection phase.
2Manufacturing precision
If precision-machined copper bars are used, then electrical performance is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The positioning tool provides the necessary positioning function during injection, allowing bars to be inserted with larger clearances without requiring precision machining. The bars themselves serve their electrical function adequately with as-extruded dimensions, eliminating the need for expensive precision machining operations.
Solution Approach 2:
The invention changes the tolerance parameter for bar insertion, allowing larger clearances between bars and slots. This parameter change enables the use of as-extruded bars instead of precision-machined bars, significantly reducing manufacturing cost while the positioning tool ensures proper positioning during injection.
3Reliability
If firm clamping is applied to bars, then bar retention is improved, but design freedom and ease of insertion are reduced
Solution Approach 1:
The positioning tool is inserted into the cavity to preliminarily hold the bars before injection. This preliminary positioning action enables the use of various bar and slot shapes without firm clamping, as the positioning tool provides temporary support during injection, thereby maintaining reliability while preserving design freedom.
Solution Approach 2:
The positioning tool serves as a temporary intermediary that enables design freedom. It allows bars with various cross-sectional shapes (rectangular, triangular, trapezoidal) to be inserted with larger clearances and held in place during injection, then removed to allow the optimized bar and slot designs to function without restrictive clamping arrangements.
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 method ensures bars remain in place during injection without additional clamping, reduces manufacturing complexity, and allows for design flexibility in slot and bar shapes, optimizing electrical performance and reducing costs by avoiding expensive machining and the need for precise copper bars.
Implementation Method 1
aluminum is injected under pressure to form bars which are connected to the outside of the laminations stack by short-circuiting rings
Data Source
AI summary
A method for manufacturing a rotor of a rotary electric machine, including a stack of magnetic laminations defining the slots in which bars made from a first electrically conducting material are received, in which method a second electrically conducting material, different from the first, is injected using an injection machine, from the front of the laminations stack, the bars being held at their rear end against the pressure associated with the injection by a positioning tool that passes through a cavity used for forming a short-circuiting ring at the rear of the laminations stack.