Abstract: A motor driving assembly includes a motor. The motor includes an outer housing, and a rotor and a brush holder received in the outer housing. The rotor includes a rotary shaft extending out of the outer housing. A commutator is fixed on a shaft portion of the rotary shaft within the outer housing. Brushes for contacting the commutator are disposed on the brush holder. A visible identification mark fixed relative to the rotary shaft is disposed outside the outer housing of the motor, such that a relative position between the brushes and the commutator in a rotational direction of the rotary shaft is identifiable by reference to a position of the visible identification mark relative to the outer housing in the rotational direction of the rotary shaft. As such, the commutator can be prevented from stalling at a position where arcing noise may be easily generated.

Abstract: A motor driving assembly includes a motor. The motor includes an outer housing, and a rotor and a brush holder received in the outer housing. The rotor includes a rotary shaft extending out of the outer housing. A commutator is fixed on a shaft portion of the rotary shaft within the outer housing. Brushes for contacting the commutator are disposed on the brush holder. A visible identification mark fixed relative to the rotary shaft is disposed outside the outer housing of the motor, such that a relative position between the brushes and the commutator in a rotational direction of the rotary shaft is identifiable by reference to a position of the visible identification mark relative to the outer housing in the rotational direction of the rotary shaft. As such, the commutator can be prevented from stalling at a position where arcing noise may be easily generated.

Abstract: A rotor for an electric motor has an iron core and a winding wound about teeth of the rotor core. Slots are formed between the teeth to accommodate coils of the winding. The winding includes several layers of windings distributed in the radial direction of the rotor. Each winding layer has a plurality of coils with the coils of each winding layer being wound on the teeth in the circumferential direction of the rotor. The overall center of gravity of the winding layers is substantially positioned at the geometric center of the rotor. Thus the center of gravity of the entire winding is located substantially at the geometric center of the rotor, thereby preventing noise caused by unstable rotation due to the deviation between the center of gravity of the winding and the geometric center of the rotor.

Abstract: A commutator includes a first body and a second body which are separately made of electrically insulating material, a plurality of commutator segments fixed on an outer surface of the first body and a plurality of commutator terminals. The first body is a hollow cylinder with two opposite ends. Each terminal has a contact area for contacting a corresponding one of the commutator segments. The second body has a base and a ring wall extending from the base, and one end of the first body is received in a space defined by the base and the ring wall, with the contact area of each terminal being in tight contact with the corresponding commutator segment at the inner side of the ring wall.

Abstract: A thrust bearing assembly for supporting an end surface against an axial load, includes a first part with a chamber; a second part disposed in the chamber and having a load surface facing the end surface; and a third part fixed with the first part and spaced from the second part. A reservoir for storing lubricant is formed in the chamber between the second part and third part. A narrow passage communicates the reservoir with the load surface to allow the lubricant to flow from the reservoir to the load surface to lubricate the interface between the load surface and the end surface when the axial load rotates.

Abstract: A motor for a fuel pump includes a rotor which includes a shaft, a rotor core and a commutator fitted on the shaft. The rotor core is formed by stacking together a plurality of aligned laminations and includes a plurality of salient poles arranged along a circumference thereof. A center line of gravity of the rotor deviates from a rotational axis of the rotor. The rotor core has a first groove in one of the poles close to the center line of gravity of the rotor. The first groove extends from a first axial end of the rotor core to an axial middle portion of the rotor core.

Abstract: A power tool has a handle and a body. The handle is provided with a battery. A motor is fixed inside a shell of the tool. An impeller is driven by the motor to create an air current to cool the motor and the battery. A plurality of air outlets are formed in the shell at a position corresponding to the impeller. An air current channel is formed inside the handle and the body and connected to the environment via holes in an enclosure of the battery. A part of the air current passes through the air current channel to cool the battery before reaching the motor.

Abstract: An electric motor includes a stator and a rotor rotatably installed in the stator. The stator has a housing and a plurality of permanent magnets. The outer diameter of the housing is less than 40 mm and the ratio of the maximum thickness of the magnets in the radial direction of the rotor to the diameter of the rotor is in the range of 1:7 to 1:50.

Abstract: An electric motor has a stator and a rotor rotatably installed in the stator. The stator includes a housing, a plurality of magnets installed at an inner surface of the housing, a brush card installed inside of the housing, brushes mounted on the brush card, lead wires for connecting to a power source and feeding power to the brushes, and an end cap attached to an end of the housing and covering the brushes. The rotor includes a shaft, a commutator fixed on the shaft, a rotor core fixed on the shaft and a winding wound on the rotor core and connected to the commutator. An EMI suppression component is mounted on the brush card and covered by the end cap, and the lead wires extends through the EMI suppression component.

Abstract: A rotor for an electric motor has an iron core and a winding wound about teeth of the rotor core. Slots are formed between the teeth to accommodate coils of the winding. The winding includes several layers of windings distributed in the radial direction of the rotor. Each winding layer has a plurality of coils with the coils of each winding layer being wound on the teeth in the circumferential direction of the rotor. The overall center of gravity of the winding layers is substantially positioned at the geometric center of the rotor. Thus the center of gravity of the entire winding is located substantially at the geometric center of the rotor, thereby preventing noise caused by unstable rotation due to the deviation between the center of gravity of the winding and the geometric center of the rotor.

Abstract: An electric motor has a pair of brushes for transferring power to windings of a wound rotor by making sliding contact with a cylindrical commutator. Each brush has a body with a pair of end surfaces, and a contact surface extending between the end surfaces and configured to slidingly contact a cylindrical circumferential surface of the commutator. The extending direction of the contact surface is inclined relative to the axial direction of the commutator, and the contact surface is V-shaped when viewed in the extending direction thereof.

Abstract: A small PMDC motor has a wound salient pole armature. The armature 22 has a winding guide 38 disposed within each winding tunnel 36 formed between adjacent salient poles of the armature. The winding guide 38 is arranged to separate the radially inner portion of the respective winding tunnel whereby windings 30 wound about the adjacent salient poles of the armature are restrained from entering into the opposite radially inner portion of the winding tunnel 36.

Abstract: A commutator includes a first body and a second body which are separately made of electrically insulating material, a plurality of commutator segments fixed on an outer surface of the first body and a plurality of commutator terminals. The first body is a hollow cylinder with two opposite ends. Each terminal has a contact area for contacting a corresponding one of the commutator segments. The second body has a base and a ring wall extending from the base, and one end of the first body is received in a space defined by the base and the ring wall, with the contact area of each terminal being in tight contact with the corresponding commutator segment at the inner side of the ring wall.

Abstract: A thrust bearing assembly for supporting an end surface against an axial load, includes a first part with a chamber; a second part disposed in the chamber and having a load surface facing the end surface; and a third part fixed with the first part and spaced from the second part. A reservoir for storing lubricant is formed in the chamber between the second part and third part. A narrow passage communicates the reservoir with the load surface to allow the lubricant to flow from the reservoir to the load surface to lubricate the interface between the load surface and the end surface when the axial load rotates.

Abstract: Brush gear of a motor has a brush card with a plurality of brushes installed at one side thereof. Each brush is electrically connected with a connector. Two motor terminations provide power to the brushes via the corresponding connectors and at least one wire connects two of the connectors. Each of said two of the connectors has a hole to receive one end of the wire and at least two fingers extends from an edge of the hole inclined toward the axis of the hole, such that when the end of the wire extends through the hole, the fingers are resiliently deformed and grip the wire to prevent withdrawal of the wire from the hole.

Abstract: A motor for a fuel pump includes a rotor which includes a shaft, a rotor core and a commutator fitted on the shaft. The rotor core is formed by stacking together a plurality of aligned laminations and includes a plurality of salient poles arranged along a circumference thereof. A center line of gravity of the rotor deviates from a rotational axis of the rotor. The rotor core has a first groove in one of the poles close to the center line of gravity of the rotor. The first groove extends from a first axial end of the rotor core to an axial middle portion of the rotor core.

Abstract: An electric motor includes a stator and a rotor rotatably installed in the stator. The stator has a housing and a plurality of permanent magnets. The outer diameter of the housing is less than 40 mm and the ratio of the maximum thickness of the magnets in the radial direction of the rotor to the diameter of the rotor is in the range of 1:7 to 1:50.