Makita Corporation

Fuminari Fujii

Kei Kouda

Makoto Chikaraishi

Ryosuke Suzuki

Yusuke Ichioka

An electric work machine is driven appropriately. An electric work machine includes a motor including a stator, a rotor rotatable relative to the stator, and a rotor shaft fixed to the rotor, an output unit drivable by the rotor shaft, a motor case accommodating the stator and the rotor, a magnet located inside the motor case and rotatable by the rotor, and a magnetic sensor located inside the motor case to detect the magnet.

Electric work machine

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 () having a rotor (), which rotates about a rotational axis relative to a stator (A;B;C;D); an output part () driven by the rotor; and a temperature-detecting device () disposed on or in the stator. The stator includes: a stator core () having teeth (), which radially protrude from a yoke (); an insulator (), which has tooth-covering parts () that respectively cover at least a portion of surfaces of the respective teeth and is fixed to the stator core; and coils () respectively wound on the teeth over the tooth-covering parts. The temperature-detecting device is disposed in a recess () provided on (in) the insulator.

An electric work machine is driven appropriately. An electric work machine includes a motor including a stator, a rotor rotatable relative to the stator, and a rotor shaft fixed to the rotor, an output unit drivable by the rotor shaft, a plurality of heat-radiating fins, a motor case having an outer surface receiving the plurality of heat-radiating fins and accommodating the stator and the rotor, a cooling fan located outside the motor case and rotatable by the rotor shaft, and a duct including a guide to guide air through the cooling fan to a fin passage between adjacent heat-radiating fins of the plurality of heat-radiating fins.

A brushless motor is at least partially located in a hermetically sealed space. An electric work machine includes a brushless motor, an output unit, a motor case, a lead wire, and a first seal. The brushless motor includes a stator, a rotor rotatable with respect to the stator, and a rotor shaft fixed to the rotor. The output unit is drivable by the rotor shaft. The motor case includes an internal space and a wiring passage. The internal space accommodates the stator and the rotor. The lead wire is located in the wiring passage connecting the internal space and an external space of the motor case. The first seal seals between the lead wire and the motor case.

An electric work machine is drivable appropriately when a brushless motor generates heat. The electric work machine includes a brushless motor including a stator, a rotor rotatable with respect to the stator, and a rotor shaft fixed to the rotor, an output unit drivable by the rotor shaft, a motor case accommodating the stator and the rotor, and a cooling fan located outside the motor case and rotatable by the rotor shaft.

An electric work machine includes a smaller motor. An electric work machine includes a motor and a housing accommodating the motor. The motor includes a stator and a rotor rotatable about a rotation axis. The stator includes a stator core, an insulator fixed to the stator core, a plurality of coils fixed to the insulator, and a terminal connected to each of the plurality of coils. The housing includes at least one first tab in contact with at least a part of a surface of the stator. The at least one first tab is at the same position as at least a part of the terminal in an axial direction parallel to the rotation axis.

An electric work machine includes a smaller motor. An electric work machine includes a motor including a stator and a rotor rotatable about a rotation axis, and a sensor board including a rotation sensor that detects rotation of the rotor and a plate supporting the rotation sensor. The plate includes a first surface facing an end face of the rotor in an axial direction parallel to the rotation axis and a support area receiving the rotation sensor that faces the end face, and a second surface facing at least a part of the stator. In the axial direction, a distance between the support area and the end face is shorter than a distance between at least a part of the second surface and the end face.

A power tool includes a brush holder with a brush positioned more accurately with respect to a commutator. A grinder as a power tool includes a housing, a stator fixed to the housing, a rotor rotatable relative to the stator and including a commutator and a coil, a brush that comes in contact with the commutator, a brush-holding metal plate having a screw hole and holding the brush, and a screw extending through the screw hole and directly fastened to the housing.

Growing community of inventors

Anjo, Japan

Fuminari Fujii