Johnson Electric International Ag

Johnson Electric S.a.

Hong Jiang Zhao

Yong Li

Yue Li

Yong Qing Wang

Jian Zhao

Mao Xiong Jiang

Guo Wei Sun

Qing Bin Luo

Wen Ming Wu

Chi Wai Lai

Ying Song Ye

Xiao Lin Ren

Zhao Sen Meng

Xian Xue Ao

Bei Bei He

A permanent magnet motor has a number of permanent magnets forming permanent magnet poles. Each magnet has an outer surface that is an arc surface with a convex middle. An inner surface of the magnet is a curved surface with a concave middle. The curved surface has an arc surface section and two planar surface sections. The arc surface has a pole arc angle &#x3b1; of 0.7 to 0.96, and the ratio of an arc angle &#x3b2; of the arc surface section to the pole arc angle &#x3b1; is 0.15 to 0.35. The shape of the inner surface of the magnet creates uneven air gaps between the rotor poles and the stator core poles. This reduces cogging torque, increases the motor efficiency, and reduces the motor noise.

Permanent magnet motor

An electric motor has a wound stator and an outer rotor. A core of the stator has outer and inner annular portions. Tooth portions extend radially outwardly from the outer annular portion. Connecting arms interconnect the outer and inner annular portions. The width of the connecting arms is less than the width of the tooth portions. The ratio of tooth height Lto distance between the roots of adjacent teeth Lis in the range of 1.0 and 1.3. The ratio of tooth width Tto Lis in the range of 0.8 and 1.0. The ratio of tooth length Tto Lis in the range of 0.5 and 0.6. The ratio of Tto outer diameter of the stator core D is in the range of 0.07 and 0.1.

Electric motor

A commutator has a conductive layer, a segment layer and an insulating layer separating the conductive layer and the segment layer. The segment layer includes multiple commutator segments. A mounting hole is defined along an axis of the commutator passing through the conductive layer. The three-layer structure of the commutator forms a capacitor having an increased confronting area and reduced inter-plate distance. The capacitor thus has a greater capacitance and hence greater EMI absorbing capability, making it possible to reduce EMI emissions without additional EMI reduction components outside the commutator. A rotor and a motor employing the commutator are also disclosed.

Commutator of an electric motor

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Shenzhen, China

Hong Jiang Zhao