Abstract:
A PMDC motor has a housing, a stator magnet disposed in an interior of the housing, and a rotor core disposed within the stator magnet. A ratio of an outer diameter of the rotor core to the outer diameter of the housing is from 0.60 to 0.67. The noise of the motor during operation is reduced by increasing the thickness of the stator magnet, reducing the outer diameter of the rotor core, reducing the air gap between the magnet and the rotor core and reducing the rotational inertia of the rotor core. The motor is particularly suited for use in vehicle HVAC systems where low noise is an important requirement.
Abstract:
A single-phase brushless motor includes a stator and a rotor rotatable with respect to the stator. The rotor includes a number of permanent magnetic poles. The stator includes a stator core and a winding wound on the stator core. The stator core includes an outer annular portion, an inner annular portion, and connecting portions connecting the inner and outer annular portions. The winding is wound around the connecting portions. The rotor is received in the inner annular portion. The inner annular portion and the rotor form a substantially uniform air gap. A recess is formed in an inner surface of a part of the inner annular portion between each pair of adjacent connecting portions. A center of each recess deviates from a center line of symmetry of the corresponding pair of connecting portions.
Abstract:
A single phase permanent magnet motor includes a stator and a rotor. The stator includes a stator core and a stator winding. The stator core includes an outer yoke, teeth extending inwardly from the outer yoke, and pole shoes extending from inner ends of the teeth. The rotor is received in a space cooperatively defined by the pole shoes. The rotor includes circumferentially arranged permanent magnetic poles. An outer circumferential surface of the permanent magnetic poles is concentric with an inner circumferential surface of the pole shoes, such that a uniform air gap is formed between the pole shoes and magnetic poles. The single phase permanent magnet motor forms the uniform air gap, which reduces the vibration and noise. The pole shoes form invisible positioning slots, which avoids the negative effect of the positioning slots to the thickness of the air gap and reduces the startup dead point.
Abstract:
A single phase motor includes a rotor including magnetic poles and a stator comprising a stator core and a winding wound on the stator core. The stator core includes a plurality of stator teeth each including a tooth body and a tooth end formed at an end of the tooth body, the tooth end comprising first and second arcuate regions facing the rotor. When the winding is not energized, a first magnetic coupling between said first arcuate region and a selected magnetic pole of said rotor is greater than a second magnetic coupling between said second arcuate region and the selected magnetic pole, said first arcuate region being offset from a selected tooth body in such a way as to enable movement of said rotor to initiate in either of two opposite directions relative to said selected tooth body upon energizing the winding.
Abstract:
A single phase brushless motor and a power tool and a car window lifer employing the motor are provided. The motor includes a stator and a rotor. The stator includes a stator core and windings. The stator core includes a yoke and teeth extending inward from the yoke. The tooth includes a tooth tip. The tooth tip includes a first pole shoe and a second pole shoe. The tooth tip forms a positioning groove facing the rotor between the first and second pole shoes. The rotor is received in a space defined between the first and second pole shoes. The rotor comprises multiple permanent magnetic poles arranged in a circumferential direction of the rotor. The first and second pole shoes are symmetrical about a central line of the tooth body, such that the rotor startup capability in one direction is greater than the rotor startup capability in an opposite direction.
Abstract:
A single phase brushless motor and an electric apparatus are provided. The motor includes a stator and a rotor. The stator includes a stator core and windings. The stator core includes a yoke and at least two teeth. The tooth includes a tooth body and a tooth tip. The tooth tip includes first and second pole shoes. The rotor is received in a space defined between the first pole shoes and the second pole shoes. Each tooth forms a positioning groove facing the rotor between the first pole shoe and the second pole shoe. The first and second pole shoes are symmetrical about a central line of the tooth body and the positioning groove deviates toward the first pole shoe, such that the rotor startup capability in one direction is greater than the rotor startup capability in an opposite direction. The single phase motor has a larger startup torque with enhanced startup capability.
Abstract:
A relay has a driving device that includes a magnet portion, two electromagnets, a yoke portion fixed to the above elements, and a rocking armature. The magnet portion includes a ferrite permanent magnet polarized in a direction perpendicular to the yoke portion and a bearing surface facing way from the yoke portion. Each electromagnet includes an iron core fixed to the yoke portion and a coil wound thereon. The two iron cores are arranged at opposite sides of the magnet portion. The rocking armature includes two arms connected to each other with an included angle formed therebetween and a convex joint of the two arms. The convex joint abuts against the bearing surface and the rocking armature pivots about the convex joint between a first position and a second position in which the rocking armature contacts a respective one of the iron cores.