Rotor Core Deformation Control in Thermoplastic Magnet Injection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for manufacturing rotors with thermoplastic-filled magnet housing holes face deformation issues due to high injection pressure, which is exacerbated by the higher viscosity of thermoplastics compared to thermosetting plastics, and require complex heating die structures to manage this pressure.
Innovation Solution
A method involving a first die heated to contact the rotor core's first end face and a second die with a passage for thermoplastic injection, where the second die is also heated to maintain the plastic's temperature and reduce viscosity, allowing for controlled injection pressure without deforming the rotor core, eliminating the need for additional structural components like slide core blocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thermoplastic is used to fill magnet housing holes, then the rotor core may be deformed by the injection pressure, but thermoplastic provides better mechanical properties and temperature resistance
Solution Approach 1:
The patent applies parameter changes by heating the thermoplastic to reduce its viscosity before injection. This temperature parameter change allows the high-strength thermoplastic material to be injected at lower pressures, thereby maintaining the mechanical properties benefit while avoiding the rotor core deformation problem.
Solution Approach 2:
The patent implements preliminary action by pre-heating the thermoplastic material before the injection process. This preliminary heating action reduces the viscosity of the thermoplastic in advance, enabling subsequent low-pressure injection that prevents rotor core deformation while still achieving the desired mechanical properties.
2Stress or pressure
If a heating die with slide core blocks is used to heat the rotor core, then the injection pressure can be limited, but the structure of the manufacturing apparatus becomes complicated
Solution Approach 1:
The patent applies the taking out principle by removing the complex slide core blocks from the heating die structure. Instead of using a complicated heating die with movable components, the patent extracts the essential heating function and implements it through a simpler structure that still achieves the goal of limiting injection pressure.
Solution Approach 2:
The patent merges the heating function with the injection system in a simplified integrated manner. Rather than using separate complex heating die components, the heating capability is combined with the injection apparatus in a more straightforward configuration, reducing overall device complexity while maintaining pressure control.
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 effectively limits the increase in viscosity and injection pressure of thermoplastic, preventing rotor core deformation and simplifying the manufacturing apparatus structure by maintaining the plastic's temperature and ensuring efficient filling of magnet housing holes without additional structural complexity.
Implementation Method 1
causing a first die to contact the first end face... in a state in which the first die is heated
Implementation Method 2
When the rotor core is heated by the heating die, the temperature of the thermoplastic is unlikely to decrease
Data Source
AI summary
A method for manufacturing a rotor includes, with a magnet accommodated in a magnet housing hole of a rotor core, causing a first die to contact a first end face of the rotor core and causing a second die to contact a second end face of the rotor core. The method also includes injecting the thermoplastic into the magnet housing hole through a passage of the second die in a state in which the first die and the second die are respectively in contact with the first end face and the second end face and the first die is heated.