Makita Corporation

Kei Kouda

Akira Niwa

Hideki Abe

Akira Naito

Fuminari Fujii

An electric work machine includes a stator including a stator core, an insulator fixed to the stator core, and a coil mounted on the insulator, a rotor at least a part of which is disposed on an outer circumferential side of the stator, the rotor including a magnet, a stator base including a first heat dissipation fin and supporting the stator core, and an output unit driven by the rotor.

Electric work machine

An electric work machine () includes: an inner-rotor-type brushless motor () having a stator () disposed around a rotor (); and an output part (), which is directly or indirectly driven by the rotor. The rotor comprises a rotor core () and eight permanent magnets () fixed to the rotor core. The stator comprises a stator core (), one or more insulators () fixed to the stator core, and six coils (), which are respectively wound on teeth (T) of the stator core via the insulator(s).

An electric work machine includes a brushless motor shortened in the direction of a motor shaft and allowing the rotational balance of a rotor to be easily adjustable. The electric work machine includes a brushless motor including a stator and a rotor, and at least one motor bearing supporting the rotor in a rotatable manner. The rotor includes a magnet being cylindrical and a magnet holder being hollow cylindrical or solid cylindrical. The magnet holder has a recess recessed in an axial direction, holds the magnet with the magnet being exposed in a radial direction, and has an axial length longer than the magnet. The magnet holder is partially exposed. The at least one motor bearing is at least partially received in the recess.

A power tool includes a brushless motor having a stator and a rotor. The stator includes a stator core having teeth, first and second insulators fixed to the stator core, and coils respectively wound around the teeth, all of the coils being wound around the first and second insulators. The rotor includes a rotor core disposed in the interior of the stator, a rotary shaft fixed to the rotor core, and one or more permanent magnets fixed to the rotor core. Power supply lines are configured to respectively supply current to the coils. Fusing terminals are fixed to the first insulator members. The fusing members respectively pinch the power supply lines and are thereby respectively electrically connected to the power supply lines.

Power tool

An electric work machine in one aspect of the present disclosure includes a motor, a driver, and a temperature sensor. The motor includes a stator, and a rotor. The stator includes a cylindrical body, a tooth, and a coil. The cylindrical body includes a first inner circumferential surface. The tooth is disposed to stand on the first inner circumferential surface. The coil is wound around the tooth. The coil generates a magnetic force in response to receiving an electric power. The temperature sensor is installed in/on the tooth.

An electric work machine includes a first brushless motor including a first stator and a first rotor combined with the first stator, and a controller. The first stator includes a first stator core and multiple first coils wound around multiple teeth on the stator core. The controller magnetizes the teeth to cause the first rotor to rotate about a rotation axis. In a plane orthogonal to the rotation axis, the first stator core has the same shape as a second stator core in a second stator used in a second brushless motor in another electric work machine. The first rotor can be combined with the second stator. The first rotor has a different number of poles from a second rotor used in the second brushless motor.

Electric work machine and production method for electric work machine

An electric work machine () includes: a brushless motor having a stator disposed around a rotor (); and an output part driven by the rotor. The rotor has a rotor core () and first and second magnetic-pole parts (S,N) disposed around a circumferential direction of the rotor core. When the induced voltage of the brushless motor is given as Va, the power-supply voltage of the brushless motor is given as Vb, the rotational speed of the brushless motor is given as ω, a first induced voltage constant, which is expressed by Va/ω, is given as Ea [V/krpm], a pole-pairs count, which is the number of the first magnetic-pole parts or the second magnetic-pole parts, is given as Pi, and a second induced voltage constant, which is expressed as Ea/Pi, is given as Eb [V/krpm·pole-pairs count], the motor satisfies the condition: Eb≤0.025×Vb.

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, such as a lawn mower includes a motor case () fixed inside a main-body housing (). A brushless motor () is housed inside the motor case () and includes a stator () having a stator core (), coils (), and upper and lower insulators (), and a rotor () disposed inward of the stator () and having a rotary shaft (). A spindle () is driven by the rotary shaft (). The motor case () holds the stator () and axially supports the rotary shaft () via bearings (). One or more insulating members, such as an insulating cap () and/or a resin layer (), provide electrical insulation between the stator core () and the rotary shaft ().

A power tool includes a brushless motor that has a stator including a tubular stator core, a rotor disposed in the tubular stator core, first and second electrically insulating members affixed to opposite ends of the stator core and a plurality of coils. A sensor-circuit board is supported by the first electrically insulating member. The first electrically insulating member is bounded by a first plane perpendicular to the rotational axis and a second plane perpendicular to the rotational axis, and the sensor-circuit board is located between the first plane and the second plane.

An electric work machine includes a brushless motor including a stator including a stator core, an electrical insulator located on the stator core, and at least one coil wound around the stator core with the electrical insulator in between, and a rotor rotatable with respect to the stator, and an output unit drivable by the brushless motor. The stator core has a through-hole and/or a recess to lock rotation of the stator with a screw.

A power tool includes a motor () having a stator (), a rotor () and three terminals (). The stator includes a tubular stator core () having six teeth (), first and second electrically insulating members () affixed to the stator core, and six coils () wound around the teeth such that three phases are defined. The three terminals are held by the first electrically insulating member and are respectively electrically connected to the three phases. All of the six coils may be formed by winding a single continuous winding wire () sequentially around each of the six teeth. All of the three terminals () may be disposed within a semicircular area of the stator core. At least a first crossover wire portion () of the winding wire may be disposed on the second electrically insulating member.

Growing community of inventors

Anjo, Japan

Kei Kouda