Title:
ELECTRIC TOOL
Document Type and Number:
WIPO Patent Application WO/2016/002542
Kind Code:
A1
Abstract:
An electric tool is provided which prevents anomalies in motor rotation due to dust and moisture sucked in together with cooling air, and which is configured such that rotational position detection operations and switch operations are not affected. This electric tool drives a brushless DC motor (6) using a controller, and comprises a rear first bearing (17) and a front second bearing of a rotation shaft, a housing having an air window, and a cooling fan that sucks in outside air from the air window in order to generate a cooling airflow. In the interval between the stator core (8) and a bearing holder (19) that holds the first bearing (17), an insulating cover member (15) is provided to prevent the cooling air from flowing through the space between a rotor (7) and the stator core (8). The first bearing (17) is kept from being exposed to the cooling airflow by closing off the upstream side of the first bearing (17) by means of a cap member (61b, 62).
Inventors:
TAKEDA YUUKI (JP)
Application Number:
PCT/JP2015/067725
Publication Date:
January 07, 2016
Filing Date:
June 19, 2015
Export Citation:
Assignee:
HITACHI KOKI KK (JP)
International Classes:
B25F5/00; B24B23/02
Foreign References:
| JP2004322274A | 2004-11-18 | |||
| JP2008296306A | 2008-12-11 | |||
| JP2002127048A | 2002-05-08 | |||
| JPH07299606A | 1995-11-14 | |||
| JPS61199442A | 1986-09-03 | |||
| JP2007196363A | 2007-08-09 | |||
| JP2009072880A | 2009-04-09 | |||
| JP2012139783A | 2012-07-26 |
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