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 core and a winding, the rotor comprises arotor core and a rotating shaft, corresponding positions of two ends of the rotating shaft are respectively sleeved with a bearing, and two ends of the casing are respectively provided with a bearingbracket. The brushless motor further comprises a conducting strip used for adjusting capacitive reactance between the stator iron core and the bearing bracket, the conducting strip is attached to theouter circumferential face of the casing, and in the radial direction of the casing, the conducting strip and the stator iron core have at least part of the opposite area. The conducting strip is attached to the outer peripheral surface of the casing, so that the conducting strip and the stator core have opposite areas, coupling capacitance is formed between the stator core and the conducting strip, the bearing bracket is located at the end of the casing, equivalent capacitance between the stator core and the bearing bracket is adjusted, potential between the bearing outer ring and the bearing inner ring is balanced, and the service life of the motor is prolonged. The potential between the bearing outer ring and the bearing inner ring is close, so that the shaft voltage is reduced, and the bearing is prevented from generating electric corrosion.

Description

technical field [0001] The invention belongs to the field of motors, and more particularly, relates to a brushless motor and electrical equipment using the brushless motor. Background technique [0002] In recent years, due to the trend of energy saving of electrical equipment such as air-conditioning units, high-efficiency brushless DC motors are used instead of induction motors to drive loads such as fans, pumps, and gears. These brushless DC motors are generally driven by inverters, which use a pulse width modulation (Pulse Width Modulation) method (hereinafter referred to as PWM) as a driving method. When using the PWM drive 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, a coupling capacitance will be generated between the various structural components of the motor, and this common mode voltage will A loop is formed through the coupling capacitance between the stator, rotor, p...

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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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