Brushless motors and electrical equipment

Abstract

The invention provides a brushless motor and electrical equipment. The brushless motor includes a casing, a stator and a rotor. The stator includes a stator core and windings. The rotor includes a rotor core and a rotating shaft. A bearing is set on the rotating shaft. Bearing brackets are respectively installed at each end, and each bearing bracket is insulated from the stator core. At least one of the bearing brackets and the stator core is provided with a conductive sheet for balancing the potential of the inner ring of the bearing and the outer ring of the bearing. The conductive sheet Electrically connected to the stator core and one of the adjacent bearing brackets. In the brushless motor, a conductive sheet is arranged between the stator core and the bearing bracket, and the conductive sheet is electrically connected to the stator core and one of the adjacent bearing brackets, so that the conductive sheet forms a capacitor with the stator core or the adjacent bearing bracket. connection, and then adjust the capacitive reactance between the stator core and the bearing bracket to balance the potential of the bearing outer ring and the bearing inner ring, so that the potential of the bearing outer ring and the bearing inner ring is similar to reduce the shaft voltage and avoid the bearing. 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, rotor core, bearing bracket and other parts, which w...

AI Technical Summary

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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