US 9,812,932 B2
Motor
Kazuya Kitaji, Kyoto (JP); Jun Nagasawa, Kyoto (JP); and Keizo Furukawa, Kyoto (JP)
Assigned to NIDEC CORPORATION, Kyoto (JP)
Filed by Nidec Corporation, Kyoto (JP)
Filed on Apr. 20, 2015, as Appl. No. 14/690,622.
Claims priority of application No. 2014-131330 (JP), filed on Jun. 26, 2014.
Prior Publication US 2015/0381017 A1, Dec. 31, 2015
Int. Cl. H02K 11/00 (2016.01); H02K 1/16 (2006.01); H02K 1/30 (2006.01); H02K 1/27 (2006.01); H02K 29/08 (2006.01)
CPC H02K 11/0021 (2013.01) [H02K 1/16 (2013.01); H02K 1/2733 (2013.01); H02K 1/30 (2013.01); H02K 29/08 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A motor comprising:
a stationary portion; and
a rotating portion configured to rotate about a rotation axis extends in a vertical direction; wherein
the rotating portion includes:
a shaft extending along the rotation axis; and
a rotor configured to rotate together with the shaft;
the stationary portion includes:
a stator located radially outside of the rotor; and
a magnetic sensor located above the rotor to detect a rotational position of the rotor;
the rotor includes:
a tubular rotor core including a ferromagnetic body and fixed to the shaft;
a rotor magnet located radially outside of the rotor core and under the magnetic sensor, in contact with the rotor core or located opposite to the rotor core with a first gap intervening therebetween, and including an upper end surface located at an axial level higher than an axial level of an upper end surface of the rotor core; and
at least one rotor holder including a ferromagnetic body, and located above the rotor core and radially inside of the rotor magnet, the rotor holder being defined by laminated steel sheets;
the rotor core is defined by laminated steel sheets placed one upon another in an axial direction; and
the rotor holder includes an outer cylindrical portion in contact with the rotor magnet or located opposite to the rotor magnet with a second gap intervening therebetween.