公开(公告)号：US20200287482A1

公开(公告)日：2020-09-10

申请号：US16648905

申请日：2019-01-11

Applicant: Panasonic Intellectual Property Management Co., Ltd.

Inventor： Fumiiki YONEDA ,  Koichiro ESAKA

IPC: H02P3/18 ,  H02P27/08 ,  H02P25/022

Abstract: A control circuit for an electric tool according to the present invention, includes a permanent magnet synchronous motor, a plurality of switching elements, and a PWM inverter circuit that drives the permanent magnet synchronous motor. The control circuit includes a current detector that detects a current flowing through the PWM inverter circuit. When braking the permanent magnet synchronous motor, the control circuit limits a current flowing through the permanent magnet synchronous motor and the PWM inverter circuit, to a predetermined current limit value. At the same time, by switching low-side switching elements or high-side switching elements of the PWM inverter circuit, the control circuit boosts an induced electromotive voltage of the permanent magnet synchronous motor, and regenerates a regenerative current to the battery.

公开(公告)号：US20220123610A1

公开(公告)日：2022-04-21

申请号：US17428198

申请日：2019-11-21

Applicant: Panasonic Intellectual Property Management Co., Ltd.

Inventor： Koichiro ESAKA ,  Akito NAKAMURA ,  Kenji OKADA ,  Mitsumasa MIZUNO

IPC: H02K1/18 ,  H02K3/38 ,  H02K3/50 ,  H02K1/17

Abstract: An electric tool includes a motor. The motor includes a stator core and a rotor. The rotor has an output shaft and rotates with respect to the stator core. The stator core includes: an inner cylindrical portion having a circular cylindrical shape; and a plurality of teeth. Inside the inner cylindrical portion, the rotor is arranged. Each of the plurality of teeth includes a body portion and a tip piece. The body portion protrudes outward from the inner cylindrical portion along a radius of the inner cylindrical portion. The tip piece extends, from a tip part of the body portion, in a direction intersecting with a direction in which the body portion protrudes.

公开(公告)号：US20240243623A1

公开(公告)日：2024-07-18

申请号：US18434702

申请日：2024-02-06

Applicant: Panasonic Intellectual Property Management Co., Ltd.

Inventor： Koichiro ESAKA ,  Akito NAKAMURA ,  Kenji OKADA ,  Mitsumasa MIZUNO

IPC: H02K1/18 ,  H02K1/17 ,  H02K3/38 ,  H02K3/50

CPC classification number: H02K1/187 ,  H02K1/17 ,  H02K3/38 ,  H02K3/50

Abstract: An electric tool includes a motor. The motor includes a stator core and a rotor. The rotor has an output shaft and rotates with respect to the stator core. The stator core includes: an inner cylindrical portion having a circular cylindrical shape; and a plurality of teeth. Inside the inner cylindrical portion, the rotor is arranged. Each of the plurality of teeth includes a body portion and a tip piece. The body portion protrudes outward from the inner cylindrical portion along a radius of the inner cylindrical portion. The tip piece extends, from a tip part of the body portion, in a direction intersecting with a direction in which the body portion protrudes.

公开(公告)号：US20220131434A1

公开(公告)日：2022-04-28

申请号：US17428922

申请日：2019-11-21

Applicant: Panasonic Intellectual Property Management Co., Ltd.

Inventor： Mitsumasa MIZUNO ,  Akito NAKAMURA ,  Koichiro ESAKA ,  Kenji OKADA

IPC: H02K1/276 ,  H02K7/14 ,  H02K21/16

Abstract: An electric tool includes a motor. The motor includes a stator core and a rotor. The rotor rotates with respect to the stator core. The rotor includes: a rotor core having a circular cylindrical shape; a plurality of permanent magnets; and an output shaft. The output shaft is held inside the rotor core. The plurality of permanent magnets are arranged as spokes around a center of the rotor core.