Brushless motor and electrical equipment

Abstract

The invention provides a brushless motor and electrical equipment, the brushless motor comprises a casing, a stator and a rotor, the stator comprises a stator iron core and a winding, the rotor comprises a rotor core and a rotating shaft, the rotating shaft is sleeved with a bearing, two ends of the casing are each provided with a bearing bracket, conducting strips are arranged on the peripheral side of the stator iron core at intervals, the conducting strips and the stator iron core have at least a part of opposite area, the conducting strips and at least one bearing bracket are arranged in an insulating mode, an electric strip is attached to the outer surface of each bearing bracket, a dielectric layer is arranged between the electric strip and the corresponding bearing bracket, and theelectric strips are electrically connected with the conducting strips. The conducting strips are arranged on the peripheral side of a stator iron core at intervals, so that coupling capacitance is formed between the stator iron core and the conducting strips; the electric strips are arranged on the bearing brackets, so that the capacitor is formed between the electric strips and the bearing brackets, and the electric strips are electrically connected with the conducting strips, thereby adjusting the capacitive reactance between the bearing brackets and the stator iron core, reducing the potential difference between an inner ring and an outer ring of a bearing, reducing the shaft voltage and avoiding electric corrosion.

Description

technical field [0001] The invention belongs to the field of motors, and more specifically relates to a brushless motor and electrical equipment using the brushless motor. Background technique [0002] In recent years, due to the energy-saving trend of air-conditioning units, high-efficiency brushless DC motors have been used to drive fans instead of induction motors. These brushless DC motors are generally driven by an inverter, which uses a pulse width modulation (Pulse Width Modulation) method (hereinafter referred to as PWM) as a driving method. When using the PWM driving method, since the neutral point potential of the winding is not zero, a common-mode voltage will be generated; in the case of high frequency, coupling capacitance will be generated between the structures of the motor, and this common-mode voltage will pass through The coupling capacitance and bearing capacitance form a loop between the stator, rotor, permanent magnet, bearing bracket and other parts, w...

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Problems solved by technology

[0003] The purpose of the embodiments of the present invention is to provide a brushless motor to solve the problem in the prior art that the shaft voltage of the brushless motor is too high and cause electric corrosion of the bearing

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