公开(公告)号：US11309811B2

公开(公告)日：2022-04-19

申请号：US17013977

申请日：2020-09-08

Applicant: MAKITA CORPORATION

Inventor： Kiyoshi Aoyama ,  Hitoshi Suzuki

IPC: H02P3/20 ,  H02P3/22

Abstract: An electric working machine may include a brushless motor and a motor controller. The motor controller may include three upper switching elements, three lower switching elements, and a control unit. The control unit may be configured to execute a short-circuit braking operation for applying a braking force to the brushless motor by bringing the three upper switching elements into a non-conductive state and bringing the three lower switching elements into a conductive state. The control unit may be configured to start the short-circuit braking operation at a predetermined timing. When the short-circuit braking operation is started at the predetermined timing, polarities of induced voltages of first to third phase terminals of the brushless motor are reversed by a time when an electrical angle of the brushless motor increases by 180 degrees from the start of the short-circuit braking operation.

公开(公告)号：US11646639B2

公开(公告)日：2023-05-09

申请号：US16970726

申请日：2019-03-01

Applicant: MAKITA CORPORATION

Inventor： Kiyoshi Aoyama

IPC: H02K11/215 ,  H02K1/276 ,  H02K7/14 ,  H02K21/16 ,  B25F5/00

CPC classification number: H02K11/215 ,  B25F5/00 ,  H02K1/276 ,  H02K7/145 ,  H02K21/16 ,  H02K2211/03

Abstract: A vibration driver drill as an electric power tool includes a brushless motor that includes a rotor and a sensor circuit board that detects a rotation of the rotor. The rotor includes a tubular rotor core and four permanent magnets held in the rotor core so as to extend in an axial direction of the rotor core. The sensor circuit board is adjacent to a front-end part (first end portion) of the rotor core. The rotor core is provided with a recessed groove on a side surface outward between the mutually adjacent permanent magnets. The recessed groove extends from the front-end part in the axial direction of the rotor core without reaching a rear-end part (second end portion) facing the front-end part.

公开(公告)号：US09364906B2

公开(公告)日：2016-06-14

申请号：US14155358

申请日：2014-01-15

Applicant: MAKITA CORPORATION

Inventor： Kenji Abe ,  Masayoshi Okumi ,  Hidenori Nagasaka ,  Motohiro Omura ,  Masaaki Fukumoto ,  Kenji Shibata ,  Nobuyasu Furui ,  Masanori Higashi ,  Kiyoshi Aoyama

IPC: H02K7/14 ,  B23D47/12 ,  B24B23/02 ,  B24B47/12 ,  B25F5/02

CPC classification number: B23D47/12 ,  B24B23/02 ,  B24B47/12 ,  B25F5/008 ,  B25F5/02

Abstract: A hand-held power tool includes a motor having a stator and a rotor, the motor being configured to rotate the rotor at a speed of at least 40,000 rpm, an output shaft directly driven by the rotor, a tool accessory shaft configured to support a tool accessory, and a two-stage speed reducing transmission operably connecting the output shaft to the tool accessory shaft. The two-stage speed reducing transmission is configured to drive the tool accessory shaft at a rate less than the rotor speed, for example, at a rate less than or equal to 37.5% of the rotor speed.

Abstract translation: 一种手持电动工具包括具有定子和转子的电动机，所述电动机构造成以至少40,000rpm的转速旋转所述转子，由所述转子直接驱动的输出轴;工具附件轴， 工具附件，以及将输出轴与工具附件轴可操作地连接的两级减速传动装置。 两级减速传动装置构造成以小于转子速度的速度驱动工具附件轴，例如以小于或等于转子速度的37.5％的速率。

公开(公告)号：US10778057B2

公开(公告)日：2020-09-15

申请号：US15582902

申请日：2017-05-01

Applicant: MAKITA CORPORATION

Inventor： Kiyoshi Aoyama

IPC: H02K3/28 ,  H02K21/22 ,  H02K3/12 ,  H02K7/14

Abstract: An electric power tool includes a brushless motor as a driving source. The brushless motor includes a stator and a rotor. The stator includes coils wound around in three phases. In a wire winding method of the coil of the stator, when the number of slots per phase is N, the number of series of the coils per phase is A, and the number of parallel of the coils per phase is B, a relation of N=A×B (note that, N is a natural number of 3 or more and 10 or less, A is a natural number of 1 or more, and B is a natural number of 2 or more) is satisfied.

公开(公告)号：US10236739B2

公开(公告)日：2019-03-19

申请号：US14887652

申请日：2015-10-20

Applicant: MAKITA CORPORATION

Inventor： Kiyoshi Aoyama ,  Masanori Higashi ,  Takashi Momose

IPC: H02K3/28 ,  H02K3/18 ,  H02K21/22 ,  H02K7/14

Abstract: The present application discloses an electric working machine. The electric working machine includes a motor including a stator. The stator includes: a stator core haring a plurality of tooth portions radially extending along a radial direction; and a first coil, a second coil, and a third coil wound on the tooth portions. A start end of the first coil and a finish end of the second coil, a start end of the second coil and a finish end of the third coil, and a start end of the third coil and a finish end of the first coil are led out within a range of 200 degrees from the stator.

公开(公告)号：US10084360B2

公开(公告)日：2018-09-25

申请号：US14918026

申请日：2015-10-20

Applicant: MAKITA CORPORATION

Inventor： Kiyoshi Aoyama

IPC: H02K11/215 ,  H02K11/00 ,  H02K21/22 ,  H02K5/22 ,  H02K7/14

CPC classification number: H02K11/215 ,  H02K5/225 ,  H02K7/145 ,  H02K21/22

Abstract: The present application discloses an electric working machine. The electric working machine includes: a motor including a rotor; a sensor board including a magnetic sensor for detecting magnetic variation due to rotation of the rotor; and a housing which contains the motor and the sensor board. in the electric working machine, the sensor board does not cover an entire circumference of the rotor. In the electric working machine, the sensor board has a portion covering the rotor, and a portion not covering the rotor.