US 11,999,045 B2
Work tool
Yonosuke Aoki, Anjo (JP)
Assigned to MAKITA CORPORATION, Anjo (JP)
Appl. No. 17/601,961
Filed by MAKITA CORPORATION, Anjo (JP)
PCT Filed Apr. 13, 2020, PCT No. PCT/JP2020/016350
§ 371(c)(1), (2) Date Oct. 7, 2021,
PCT Pub. No. WO2020/218073, PCT Pub. Date Oct. 29, 2020.
Claims priority of application No. 2019-081354 (JP), filed on Apr. 22, 2019.
Prior Publication US 2022/0184793 A1, Jun. 16, 2022
Int. Cl. B25F 5/00 (2006.01); B25F 5/02 (2006.01); H02K 9/06 (2006.01); B26D 1/06 (2006.01)
CPC B25F 5/008 (2013.01) [B25F 5/02 (2013.01); B26D 1/06 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A work tool configured to drive a tool accessory in an oscillating manner to perform a processing operation on a workpiece, the work tool comprising:
a housing;
a spindle supported by the housing to be rotatable around a first rotational axis;
a motor housed in the housing and including a stator, a rotor, and a first shaft, the first shaft extending from the rotor and being configured to rotate integrally with the rotor around a second rotational axis;
a transmitting mechanism configured to transmit rotation of the first shaft to the spindle to cause the spindle to rotary oscillate around the first rotational axis; and
a heat dissipation part,
wherein:
the transmitting mechanism comprises:
a second shaft made of metal and coaxially coupled to the first shaft and having an eccentric part that is eccentric to the second rotational axis;
a drive bearing including an inner ring fixed around the eccentric part, an outer ring, a retainer made of plastic and between the inner ring and the outer ring, and a plurality of rolling elements rollably retained by the retainer; and
an oscillating member having a first end portion fixed to the spindle and a second end portion abutting on an outer periphery of the outer ring of the drive bearing;
the heat dissipation part is made of metal, in contact with the second shaft and configured to rotate integrally with the second shaft; and
the housing has a first path that directs an airflow for cooling the motor to the motor and a second path that (i) is different from the first path and (ii) directs an airflow to the heat dissipation part for cooling the heat dissipation part.