公开(公告)号：US11333205B2

公开(公告)日：2022-05-17

申请号：US16409955

申请日：2019-05-13

Applicant: DENSO CORPORATION

Inventor： Yugo Yamada ,  Akira Kishibuchi ,  Yohei Kushida ,  Junichi Nakagawa ,  Satoshi Kawakami ,  Toshinobu Takasaki ,  Kozo Tomokawa

IPC: F16D27/112 ,  H02K1/22

Abstract: A power transmission device includes an armature that is shaped into a circular ring form. The armature is configured to be coupled with a rotor by an electromagnetic attractive force of an electromagnet at a time of energizing the electromagnet and is configured to be decoupled from the rotor at a time of deenergizing the electromagnet. The armature has an armature-side friction surface that is configured to contact a rotor-side friction surface of the rotor at the time of energizing the electromagnet. The armature-side friction surface has a plurality of grooves, each of which extends from a radially inner end portion of the armature-side friction surface to a location that is on a radially inner side of a radially outer end portion of the armature-side friction surface.