US 11,996,743 B2
Rotor manufacturing method
Takaaki Kawashima, Kariya (JP); and Yutaka Hara, Kariya (JP)
Assigned to AISIN CORPORATION, Kariya (JP)
Appl. No. 17/632,626
Filed by AISIN CORPORATION, Aichi (JP)
PCT Filed Mar. 25, 2020, PCT No. PCT/JP2020/013476
§ 371(c)(1), (2) Date Feb. 3, 2022,
PCT Pub. No. WO2021/192122, PCT Pub. Date Sep. 30, 2021.
Prior Publication US 2022/0294321 A1, Sep. 15, 2022
Int. Cl. H02K 15/03 (2006.01)
CPC H02K 15/03 (2013.01) [Y10T 29/49012 (2015.01)] 16 Claims
OG exemplary drawing
 
1. A rotor manufacturing method involving fixing a shaft to an inner peripheral surface of a shaft insertion hole of a rotor core including a plurality of annular electromagnetic steel sheets stacked in a rotation axis direction such that the shaft insertion hole is defined, the method comprising the steps of:
providing the shaft having a cylindrical shape in which an inside diameter of a first portion of the shaft to be placed on the inner peripheral surface of the shaft insertion hole is larger than an inside diameter of a second portion of the shaft located on one side in the rotation axis direction relative to the first portion;
inserting the shaft into the shaft insertion hole by axially moving at least one of the shaft and the rotor core such that an outer periphery of the first portion of the shaft radially faces the inner peripheral surface of the shaft insertion hole; and
fixing the shaft to the rotor core by a hydroforming process that involves filling an internal space of the shaft with a fluid and expanding the shaft with an internal pressure produced by the fluid, thus pressure-welding the first portion to the inner peripheral surface of the shaft insertion hole after the step of inserting the shaft.