Johnson Electric S.a.

Chang Lin Jin

James Ching Sik Lau

Duncan Yiu Lung Wong

Aloys J Liu

Yong Li

Jian Zhao

Yuen Tung Louie

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.

Power tool

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.

Brush design for electric motor having commutator

A direct current motor includes a stator and a rotor. The rotor has a shaft; a rotor core fixed to the shaft; a commutator fixed to the shaft; and rotor windings wound about poles of the rotor core and terminated on the commutator. The motor also has a common brush and at least two selectable brushes in sliding contact with the commutator; at least two direct current power sources; and a switching device configured to connect the common brush and a selected one of the selectable brushes with predetermined combinations of the power sources to operate the motor in different speed modes.

Electric motor

A power tool comprises a housing, a direct current motor arranged in the housing, a speed reduction mechanism coupled to a shaft of the motor, a tool head driven by the speed reduction mechanism, a first direct current power source, and a switching device. The motor comprises a common brush, a high speed brush and a low speed brush which are in sliding contact with a commutator. The switching device is configured to selectively connect the common brush and the high speed brush with the power source to operate the motor in a high speed mode and to connect the common brush and the low speed brush with the power source to operate the motor in a low speed mode.

Power tool with a DC brush motor and with a second power source

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.

Brush gear of a motor

An electric motor includes: a rotor; a stator; and brush gear. The rotor has a shaft, a rotor core and a commutator fitted to the shaft. The rotor core has 5n teeth, n being a positive integer. Two coils are wound on each tooth with each coil being wound about a single tooth and having two ends. The commutator has 10n bars forming a brush contact surface. The stator includes a yoke and a plurality of permanent magnets installed at an inner surface of the yoke and facing the rotor core. The ends of the two coils wound on each tooth are respectively connected to two pairs of adjacent bars and the center line between one pair of the two pairs of adjacent bars and the center line between the other pair of the two pairs of adjacent bars are diametrically opposed.

Electric motor and rotor therefor

A multi-pole PMDC motor has brush gear for transferring electrical power from motor terminations to its windings via a commutator. The brush gear comprises a brush card supporting at least four brush assemblies. The brush assemblies are separated into two brush groups with the brush assemblies of each group being electrically connected together by links of flexible wire.

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Shenzhen, China

Chang Lin Jin