CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority from Japanese Patent Application No. 2018-232749 filed on Dec. 12, 2018, the contents of which are hereby incorporated by reference in their entirety into this application.

BACKGROUND

1 Technical Field

The present disclosure relates to rotating electric machines and methods of manufacturing the rotating electric machines.

2 Description of Related Art

There is known a rotating electric machine in which exposed portions of electrical conductors, which are exposed from insulating coats respectively covering the electrical conductors, are encapsulated in an encapsulating resin body. Specifically, the encapsulating resin body is formed with a curable resin. The encapsulating resin body has integrally encapsulated therein the exposed portions of the electrical conductors, joints formed at the exposed portions, and part of each of covered portions of the electrical conductors which are covered with the respective insulating coats and respectively adjoin the exposed portions.

SUMMARY

According to the present disclosure, there is provided a first rotating electric machine which includes: a stator core; a stator coil mounted on the stator core and formed of electrical conductors and insulating coats respectively covering the electrical conductors; and an encapsulating resin body having part of the stator coil encapsulated therein. The stator coil has a coil end part protruding from an axial end face of the stator core. The coil end part includes exposed portions of the electrical conductors, which are exposed from the insulating coats, joints formed at the exposed portions of the electrical conductors, and covered portions of the electrical conductors which are covered with the respective insulating coats and respectively adjoin the exposed portions. The encapsulating resin body is formed, at the coil end part of the stator coil, to integrally encapsulate therein the exposed portions of the electrical conductors, the joints formed at the exposed portions, and at least part of each of the covered portions of the electrical conductors. The encapsulating resin body has a first part in which the exposed portions of the electrical conductors are encapsulated and a second part in which the at least part of each of the covered portions of the electrical conductors is encapsulated. A coefficient of linear expansion of the first part of the encapsulating resin body is lower than a coefficient of linear expansion of the second part of the encapsulating resin body.

According to the present disclosure, there is also provided a second rotating electric machine which includes: a stator core; a stator coil mounted on the stator core and formed of electrical conductors and insulating coats respectively covering the electrical conductors; and an encapsulating resin body having part of the stator coil encapsulated therein and including a filler. The stator coil has a coil end part protruding from an axial end face of the stator core. The coil end part includes exposed portions of the electrical conductors, which are exposed from the insulating coats, joints formed at the exposed portions of the electrical conductors, and covered portions of the electrical conductors which are covered with the respective insulating coats and respectively adjoin the exposed portions. The encapsulating resin body is formed, at the coil end part of the stator coil, to integrally encapsulate therein the exposed portions of the electrical conductors, the joints formed at the exposed portions, and at least part of each of the covered portions of the electrical conductors. The encapsulating resin body has a first part in which the exposed portions of the electrical conductors are encapsulated and a second part in which the at least part of each of the covered portions of the electrical conductors is encapsulated. The percentage content of the filler in the first part of the encapsulating resin body is higher than the percentage content of the filler in the second part of the encapsulating resin body.

According to the present disclosure, there is further provided a method of manufacturing a rotating electric machine. The method includes the steps of: (1) mounting a stator coil to a stator core so that a coil end part of the stator coil protrudes from an axial end face of the stator core, the stator coil being formed of electrical conductors and insulating coats respectively covering the electrical conductors, the coil end part of the stator coil including exposed portions of the electrical conductors, which are exposed from the insulating coats, joints formed at the exposed portions of the electrical conductors, and covered portions of the electrical conductors which are covered with the respective insulating coats and respectively adjoin the exposed portions; (2) immersing at least part of the coil end part of the stator coil in a liquid resin so that the exposed portions of the electrical conductors and the joints formed at the exposed portions are immersed in a first part of the liquid resin while at least part of each of the covered portions of the electrical conductors is immersed in a second part of the liquid resin, the liquid resin having a filler added thereto and being contained in a container that has an opening; and (3) curing the liquid resin, at a time point after a predetermined duration has elapsed from the immersing step, to form an encapsulating resin body in which the at least part of the coil end part of the stator coil is encapsulated, at the time point, distribution of the filler in the liquid resin having become uneven so that an amount of the filler included in the first part of the liquid resin is greater than an amount of the filler included in the second part of the liquid resin.

