US 12,011,818 B2
Electric tool
Ken Miyazawa, Ibaraki (JP); and Ryo Suzuki, Ibaraki (JP)
Assigned to Koki Holdings Co., Ltd., Tokyo (JP)
Appl. No. 17/256,635
Filed by Koki Holdings Co., Ltd., Tokyo (JP)
PCT Filed Apr. 12, 2019, PCT No. PCT/JP2019/015940
§ 371(c)(1), (2) Date Dec. 28, 2020,
PCT Pub. No. WO2020/003696, PCT Pub. Date Jan. 2, 2020.
Claims priority of application No. 2018-124317 (JP), filed on Jun. 29, 2018; and application No. 2018-124333 (JP), filed on Jun. 29, 2018.
Prior Publication US 2021/0260745 A1, Aug. 26, 2021
Int. Cl. H02K 9/06 (2006.01); B24B 23/02 (2006.01); B25F 5/00 (2006.01); H02K 15/02 (2006.01)
CPC B25F 5/008 (2013.01) [B24B 23/028 (2013.01); H02K 9/06 (2013.01); H02K 15/02 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An electric tool, having:
a motor, having a stator, a rotor located inside the stator, and a rotation shaft extending from one side to an other side;
a motor housing of a cylindrical shape, accommodating and supporting the motor;
a cooling fan, attached to the rotation shaft of the motor and rotating in synchronization with the motor; and
a power transmission mechanism, transmitting a rotational force of the motor to a tip tool, wherein
the motor is cooled by flowing an air generated by the cooling fan from an opening on one side of the motor housing toward an opening on the other side of the motor housing, wherein
the stator has a nonmagnetic insulator at one side of the stator, and
a fan guide is provided, guiding a cooling air generated by the cooling fan from an intake port to an exhaust port, and
the fan guide has a first cylindrical part, a guide surface connected to the first cylindrical part, and a second cylindrical part connected to the guide surface, and guides the cooling air to concentrate inside the stator, and
an end portion provided at one side of the second cylindrical part is located on one side of an opening surface provided on the other side of the insulator.