H02K29/08

Power tool

A power tool (1; 90) includes a motor (17) having a stator (18) and a rotor (19). The stator (18) includes front and rear insulators (21, 22) respectively disposed forward and rearward of a stator core (20) in an axial direction thereof. At least six coils (23) are respectively wound on the stator (18) such that the coils (23) are wound through the front and rear insulators (21, 22). Winding wires (23a) respectively electrically connect circumferentially-adjacent pairs of the coils (23). A short circuiting device (25) short circuits respective pairs of windings (23a) that are located diagonally or diametrically across from one another.

MOTOR CURRENT CONTROLLING CIRCUIT HAVING VOLTAGE DETECTION MECHANISM
20230021728 · 2023-01-26 ·

A motor current controlling circuit having a voltage detection mechanism is provided. A first terminal of a first low-side transistor is connected to a second terminal of a first high-side transistor. A node between the first terminal of the first low-side transistor and the second terminal of the first high-side transistor is connected to a first terminal of a motor. A first terminal of a second low-side transistor is connected to a second terminal of a second high-side transistor. A zero current detector circuit detects a voltage of the node and determines whether or not a current flowing through the motor is equal to a zero value to output a zero current detected signal according to the detected voltage. A controller circuit controls a driver circuit to turn on or off the high-side transistors and the low-side transistors according to the zero current detected signal.

MOTOR CURRENT CONTROLLING CIRCUIT HAVING VOLTAGE DETECTION MECHANISM
20230021728 · 2023-01-26 ·

A motor current controlling circuit having a voltage detection mechanism is provided. A first terminal of a first low-side transistor is connected to a second terminal of a first high-side transistor. A node between the first terminal of the first low-side transistor and the second terminal of the first high-side transistor is connected to a first terminal of a motor. A first terminal of a second low-side transistor is connected to a second terminal of a second high-side transistor. A zero current detector circuit detects a voltage of the node and determines whether or not a current flowing through the motor is equal to a zero value to output a zero current detected signal according to the detected voltage. A controller circuit controls a driver circuit to turn on or off the high-side transistors and the low-side transistors according to the zero current detected signal.

ELECTRIC WORK MACHINE AND PRODUCTION METHOD FOR ELECTRIC WORK MACHINE
20230231457 · 2023-07-20 · ·

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.

BLDC motor control system and method for solar tracking motorized window treatment operation

A motorized shade comprising a motor adapted to lower or raise a shade material for selectively covering an architectural opening based on a position of the sun. The motorized shade comprises a controller adapted to drive the motor phase according to a startup sequence by ramping up amplitude form an initial amplitude to a startup amplitude and ramping up frequency from an initial frequency to a drive frequency, drive the motor phase according to a full drive sequence to move the shade material by driving the motor phase according to a sinusoidal waveform at a set maximum amplitude and at a drive frequency, and drive the motor phase according to a wind down sequence by reducing frequency from the drive frequency to an end frequency and reducing the amplitude from the maximum amplitude to an end amplitude.

BLDC motor control system and method for solar tracking motorized window treatment operation

A motorized shade comprising a motor adapted to lower or raise a shade material for selectively covering an architectural opening based on a position of the sun. The motorized shade comprises a controller adapted to drive the motor phase according to a startup sequence by ramping up amplitude form an initial amplitude to a startup amplitude and ramping up frequency from an initial frequency to a drive frequency, drive the motor phase according to a full drive sequence to move the shade material by driving the motor phase according to a sinusoidal waveform at a set maximum amplitude and at a drive frequency, and drive the motor phase according to a wind down sequence by reducing frequency from the drive frequency to an end frequency and reducing the amplitude from the maximum amplitude to an end amplitude.

Electric motor comprising an integrated rotary encoder
11705798 · 2023-07-18 · ·

An electric motor has an end shield and a sensor for detecting a magnetic field. The sensor is integrated into the end shield of the electric motor. An electric drive unit may include a brake, in particular an electromagnetically actuatable brake, and an electric motor, where a shielding element is arranged between the sensor and the brake.

Electric motor comprising an integrated rotary encoder
11705798 · 2023-07-18 · ·

An electric motor has an end shield and a sensor for detecting a magnetic field. The sensor is integrated into the end shield of the electric motor. An electric drive unit may include a brake, in particular an electromagnetically actuatable brake, and an electric motor, where a shielding element is arranged between the sensor and the brake.

Power tool with compact motor assembly

A power tool is provided with a tool housing, a support plate provided within the tool housing, a rear tool cap mounted on a rear end of the tool housing, and a brushless direct-current (BLDC) motor received within the housing. The motor includes a stator assembly having a stator core and stator windings, a front motor bearing supported by the support plate, a rear motor bearing supported by the rear tool cap, and a rotor including a rotor core and a magnet ring mounted around the rotor core. The rotor core defines an annular recess within which at portion of the front bearing and a portion of the support plate are located such that the a radial plane intersects the front bearing, the magnet ring, and the stator core.

ELECTRIC WORK MACHINE
20230216359 · 2023-07-06 · ·

An electric work machine reduces a decrease in the detection accuracy of rotation of a rotor while avoiding generation of insufficient reluctance torque. The electric work machine includes a brushless motor including a rotor and a stator, and a magnetic sensor. The rotor includes a rotor core and permanent magnets. The magnetic sensor faces a first end of the rotor core to detect rotation of the rotor. The rotor core includes a first core including the first end and first slots, and a second core including second slots. The permanent magnets are received in the corresponding first and second slots. The first core includes a first portion between first slots adjacent in a circumferential direction. The second core includes a second portion between second slots adjacent in the circumferential direction. The first portion has a dimension smaller than a dimension of the second portion in the circumferential direction.