A method of manufacturing a motor assembly comprising a motor and an impeller coupled to a rotation shaft of the motor, the method includes disposing a plurality of balls in a ring-shaped groove formed in a surface of the impeller; rotating the impeller at a speed greater than a resonant rotation speed to move the balls to a compensation position for compensating for an eccentricity in the motor assembly; and fixing the balls at the compensation position in the groove.

A method of manufacturing a motor assembly comprising a motor and an impeller coupled to a rotation shaft of the motor, the method includes disposing a plurality of balls in a ring-shaped groove formed in a surface of the impeller; rotating the impeller at a speed greater than a resonant rotation speed to move the balls to a compensation position for compensating for an eccentricity in the motor assembly; and fixing the balls at the compensation position in the groove.

A brushless motor comprising a rotor assembly comprising a shaft, an impeller, a bearing assembly and a rotor core; a stator assembly; a frame comprising an outer portion and a support portion radially inward of the outer portion, the support portion supporting at least one of the rotor assembly and the stator assembly; and at least one strut extending between the outer portion and the support portion, wherein the strut and the stator assembly are aligned such that at least part of the strut and at least part of the stator assembly are disposed along a line substantially parallel to a rotation axis of the rotor assembly.

A brushless motor comprising a rotor assembly comprising a shaft, an impeller, a bearing assembly and a rotor core; a stator assembly; a frame comprising an outer portion and a support portion radially inward of the outer portion, the support portion supporting at least one of the rotor assembly and the stator assembly; and at least one strut extending between the outer portion and the support portion, wherein the strut and the stator assembly are aligned such that at least part of the strut and at least part of the stator assembly are disposed along a line substantially parallel to a rotation axis of the rotor assembly.

A vacuum cleaner motor device comprises a motor assembly and an expansion assembly. The motor assembly further comprises a rotor, a stator, and a main shaft. The expansion assembly further comprises a first motor support, a second motor support, a fan blade member, a fan blade member support, a PCBA assembly, a first bearing, and a second bearing. The rotor is a neodymium iron boron magnet made of neodymium iron boron, which ensures that the motor has a strong output power such that the rotating speed of the motor reaches more than 100,000 rpm. The outer circumferential diameter of the fan blade member ranges from 35 to 40 mm. Compared with conventional vacuum cleaners, the fan blade member of the present disclosure has a larger size, which ensures a stronger vacuum suction force of the vacuum cleaner and achieves better cleaning effect.

A motor includes a housing, a stator assembly disposed in the housing, the stator assembly defining a rotor cavity extending through the housing, a rotor assembly including a rotor shaft extending along a longitudinal axis, two brackets connected to the housing, the two brackets disposed, one each, at either end of the rotor cavity, and two bearings disposed, one each, on each of the two brackets, wherein the two bearings rotatably support the rotor shaft within the housing. The rotor shaft is a stepped shaft that includes end portions disposed at either end of a core portion, the core portion includes channels extending in a direction parallel to the longitudinal axis, the channels extending radially at a depth into the core portion to define a core diameter such that the core diameter is less than the first diameter.

A motor includes a housing, a stator assembly disposed in the housing, the stator assembly defining a rotor cavity extending through the housing, a rotor assembly including a rotor shaft extending along a longitudinal axis, two brackets connected to the housing, the two brackets disposed, one each, at either end of the rotor cavity, and two bearings disposed, one each, on each of the two brackets, wherein the two bearings rotatably support the rotor shaft within the housing. The rotor shaft is a stepped shaft that includes end portions disposed at either end of a core portion, the core portion includes channels extending in a direction parallel to the longitudinal axis, the channels extending radially at a depth into the core portion to define a core diameter such that the core diameter is less than the first diameter.

An electric machine comprising: a stator assembly; a rotor assembly; and a support body. The rotor assembly comprises a shaft to which is mounted a first bearing and a second bearing either side of a permanent magnet, and the support body comprises first and second bearing seats to which the bearings of the rotor assembly are mounted, wherein the first bearing is mounted to the first bearing seat by adhesive, and the second bearing is soft-mounted to the second bearing seat by an o-ring.

An electric machine comprising: a stator assembly; a rotor assembly; and a support body. The rotor assembly comprises a shaft to which is mounted a first bearing and a second bearing either side of a permanent magnet, and the support body comprises first and second bearing seats to which the bearings of the rotor assembly are mounted, wherein the first bearing is mounted to the first bearing seat by adhesive, and the second bearing is soft-mounted to the second bearing seat by an o-ring.

Noise caused by a gap between a rotor and a plate can be suppressed even when there are dimensional variations in members or assembly states. In a configuration of a stepping motor including front side and end side stator assemblies (200, 300), a rotor (400) provided with a rotor member (402) and a shaft (403) that are accommodated in the stator assemblies (200, 300), and a front plate (210) and an end plate (310) that are arranged on both sides of the stator assemblies (200, 300) in an axial direction, and are configured to couple the stator assemblies (200, 300), a projection (700) in an annular shape is provided on a surface of the front plate (210) facing the rotor member (402) to protrude toward the rotor member (402), a coil spring (800) that is interposed between the front plate (210) and the rotor member (402) is accommodated in the inner side of the projection (700), and the rotor (400) is urged toward the end plate (310) by the coil spring to be elastically pressed against the end plate (310).