Method for manufacturing core of rotating electric machine
A method for manufacturing a core of a rotating electric machine includes arranging a permanent magnet in a receptacle of a core body and injecting an anchoring material into a gap between a wall surface of the receptacle and an outer surface of the permanent magnet. A liquid crystal polymer, more specifically, liquid crystal polyester is used as the anchoring material. The liquid crystal polymer is injected at a velocity of 100 to 300 millimeters per second.
1. A method for manufacturing a core of a rotating electric machine, the method comprising:
providing a core body with a receptacle formed therein,
arranging a permanent magnet in the receptacle of the core body so as to define a gap between a wall surface of the receptacle and an outer surface of the permanent magnet,
providing a liquid crystal polymer,
activating an injection device so that the liquid crystal polymer is delivered from the injection device to a passage,
injecting the liquid crystal polymer into the gap at a velocity of 100 to 300 millimeters per second when the core body and the permanent magnet each have a temperature from 40 to 80 degrees Celsius, and
allowing the liquid crystal polymer to solidify, thereby anchoring the permanent magnet to the core body, wherein
the liquid crystal polymer is injected into the gap from a nozzle hole of a nozzle arranged at a downstream end of the passage, and
a diameter of the nozzle hole is set to 0.5 to 2.0 mm.
2. The method according to claim 1 , further comprising injecting the liquid crystal polymer into the receptacle under a pressure of 5 to 30 megapascals.
3. The method according to claim 1 , further comprising injecting the liquid crystal polymer into the gap when the liquid crystal polymer has a melt viscosity of 3.5 pascal-seconds or less.