Abstract: In a synchronous reluctance motor having a rotor having a plurality of pairs of an outer side slot formed at an outer periphery side and an inner side slot formed at inner side of the rotor. The distance between the outer periphery of the rotor and the outer side slot is determined to be the width of the stator magnetic pole portion of the stator multiplied by 0.7 to 1.3. A first total magnetic flux amount of an outer side permanent magnet disposed in the outer side slot is determined to be larger than or equal to a second total magnetic flux amount of an inner side permanent magnet disposed in the inner side slot.

Abstract: In a synchronous reluctance motor having a rotor having a plurality of pairs of an outer side slot formed at an outer periphery side and an inner side slot formed at inner side of the rotor. The distance between the outer periphery of the rotor and the outer side slot is determined to be the width of the stator magnetic pole portion of the stator multiplied by 0.7 to 1.3. A first total magnetic flux amount of an outer side permanent magnet disposed in the outer side slot is determined to be larger than or equal to a second total magnetic flux amount of an inner side permanent magnet disposed in the inner side slot.

Abstract: A frame for an electric motor is provided with a high heat discharge efficiency at low manufacturing cost wherein a plurality of cooling media paths, grooves, groove paths, media paths and communication paths are formed on the frame using a diecast process. A plurality of fins are formed in the grooves and a plurality of cooling media guide members are secured about the periphery of the frame to control the flow of the cooling media.

Abstract: A frame for an electric motor is provided with a high heat discharge efficiency at low manufacturing cost wherein a plurality of cooling media paths, grooves, groove paths, media paths and communication paths are formed on the frame using a diecast process. A plurality of fins are formed in the grooves and a plurality of cooling media guide members are secured about the periphery of the frame to control the flow of the cooling media.

Abstract: A cooling device for an electric motor includes a plurality of inwardly projected stator poles arranged in a circumferential direction such that an axially extending space is defined between two adjacent stator poles. Coils are wound on the respective stator poles and coolers are disposed in the respective spaces such that each of the coolers is in thermal contact with its neighboring coils.

Abstract: The clearance between the stator pole portions and the rotor pole portions at the axial central portion is larger than the clearance therebetween at the axial end portions. According to these characteristics, the magnetic attracting force causing objectionable acoustic noise is increased at the axial end portions of the housing and the stator in which stiffness against the magnetic attracting force is high and decreased at the axial central portion in which their stiffness against the magnetic attracting force is low. Thereby, the objectionable acoustic noise is reduced without changing the motoring torque and increasing the weight of the switched reluctance motor.

Abstract: In a switched reluctance motor, the projected poles of a rotor have feeble-magnetic portions each having a shape that extends radially inward approximately in the rotational direction from a position relative close to a radially outer end of the projected pole and to an end of the projected pole facing in a counter-rotational direction, that is, a direction opposite to the rotational direction, or a shape that has a side extending radially inward approximately in the rotational direction from a position relatively close to a radially outer end and an counter-rotational direction-facing end of the projected pole and that extends radially inward approximately in the counter-rotational direction. The feeble-magnetic portions are weaker in magnetism than the material of the rotor and reduce the magnetic attraction force occurring at the time of switching of coil energization, thereby reducing noises while ensuring generation of a desired amount of torque.

Abstract: A switched reluctance motor includes a stator having a plurality of pairs of opposing stator pole portions which project inward in the diametrical direction and which extend in the axial direction, a rotor rotatably disposed in the stator and having a plurality of rotor pole portions which project outward in the diametrical direction and which extend in the axial direction and axis portion which is rotatably supported on a housing. A plurality of coils are wound on each of the pair of the stator pole portions and an absorbing mechanism is provided for absorbing radial vibrations of the rotor which are generated by a variation of the magnetic attracting force acting on the rotor pole portions.

Abstract: A switched reluctance motor has a rotor disposed in an annular stator and formed mainly of a stack of iron plates. The rotor has pole protrusions that face the stator. The pole protrusions have weak magnetic portions provided therein. Each weak magnetic portion has a shape elongated from a leading outer point to a tailing inner point, or a shape that has a base side extending a leading outer point to a tailing inner point and that extends from the base side in the rotational direction and in the inward radial direction. The weak magnetic portions are formed of a material that has a weaker magnetism than the materials forming the other portions of the rotor.