An electric work machine includes: a motor comprising a stator including coils, a rotor rotatable relative to the stator, and a rotor shaft fixed to the rotor; an output unit driven by the rotor shaft; a motor case including a main body having an insertion opening, and a lid disposed on one side in an axial direction relative to the main body and connected to the main body to close the insertion opening; and a resin portion that includes a first portion covering the coils and a second portion disposed on one side in the axial direction relative to the first portion. The first and second portions are integrated. Each of the first and second portions has a tubular shape. A second inner diameter indicating an inner diameter of the second portion is larger than a first inner diameter indicating an inner diameter of the first portion.

An electric work machine includes: a motor comprising a stator including coils, a rotor rotatable relative to the stator, and a rotor shaft fixed to the rotor; an output unit driven by the rotor shaft; a motor case including a main body having an insertion opening, and a lid disposed on one side in an axial direction relative to the main body and connected to the main body to close the insertion opening; and a resin portion that includes a first portion covering the coils and a second portion disposed on one side in the axial direction relative to the first portion. The first and second portions are integrated. Each of the first and second portions has a tubular shape. A second inner diameter indicating an inner diameter of the second portion is larger than a first inner diameter indicating an inner diameter of the first portion.

Electric motor controllers including MOSFET transistors and Hall effect switches are described.

Electric motor controllers including MOSFET transistors and Hall effect switches are described.

The present invention may provide a motor comprising: a rotation shaft; a rotor including a coupling hole in which the rotation shaft is disposed; a stator disposed outside the rotor; and a housing for receiving the rotor and the stator, wherein the housing comprises: a body; a bracket disposed on one side of the body and including a hole and a bearing pocket part disposed along the circumferential direction with respect to the center of the hole; and a bearing disposed in the bearing pocket part, wherein the inner surface of the bearing pocket part includes a first surface, a second surface, and a third surface, and wherein the first surface comes in contact with the outer circumferential surface of the bearing, the second surface comes in contact with the upper surface of the bearing, and the third surface is disposed between the first surface and the second surface in the height direction of the bracket while being spaced apart from the outer circumferential surface of the bearing.

The described apparatus and method enable alteration of motor properties during operation of a motor. For example, the rotor of the motor may be adjustable, during motor operation, between a first diameter and a larger, second diameter. When the diameter of the rotor increases, the distance between the electromagnetic coils of the stator and the magnets of the rotor increases, thereby reducing the back-electromotor force (back-EMF) of the motor. When the back-EMF of the motor decreases, the torque of the motor decreases but the maximum revolutions per minute (RPM) increases. When the diameter of the rotor decreases, the distance between the electromagnetic coils of the stator and the magnets of the rotor decreases, thereby increasing the back-EMF of the motor. When the back-EMF of the motor increases, the torque of the motor increases but the maximum RPM decreases.

The described apparatus and method enable alteration of motor properties during operation of a motor. For example, the rotor of the motor may be adjustable, during motor operation, between a first diameter and a larger, second diameter. When the diameter of the rotor increases, the distance between the electromagnetic coils of the stator and the magnets of the rotor increases, thereby reducing the back-electromotor force (back-EMF) of the motor. When the back-EMF of the motor decreases, the torque of the motor decreases but the maximum revolutions per minute (RPM) increases. When the diameter of the rotor decreases, the distance between the electromagnetic coils of the stator and the magnets of the rotor decreases, thereby increasing the back-EMF of the motor. When the back-EMF of the motor increases, the torque of the motor increases but the maximum RPM decreases.

An electric brushless DC motor is provided including a rotor assembly having a substantially-cylindrical metallic rotor body and at least one rotor magnet mounted on a surface of the rotor body, a stator assembly rotatably disposed relative to the rotor assembly, and a molded structure formed in contact with the rotor body. The molded structure includes a main body having a first axial end that engages at least one axial end of the at least one rotor magnet to axially retain the at least one rotor magnet on the surface of the rotor body and a second axial end that integrally forms a fan adjacent the rotor body.

An electric brushless DC motor is provided including a rotor assembly having a substantially-cylindrical metallic rotor body and at least one rotor magnet mounted on a surface of the rotor body, a stator assembly rotatably disposed relative to the rotor assembly, and a molded structure formed in contact with the rotor body. The molded structure includes a main body having a first axial end that engages at least one axial end of the at least one rotor magnet to axially retain the at least one rotor magnet on the surface of the rotor body and a second axial end that integrally forms a fan adjacent the rotor body.

A method for positioning a magnetic device providing an impulse ring forming a coder and at least three magnetic detection cells forming a magnetic sensor. The impulse ring being provided with a target having pairs of magnetic poles. The number of pair of magnetic poles being counted. The magnetic detection cells are positioned around the target of the impulse ring according to the number of pair of magnetic poles and according to the number of detection cells.