Power Tool Motor with Reduced Electrical Noise

Patent metadata

Field	Value
Publication number	US-2016263679-A1
Application number	US-201615060746-A
Country	US
Kind code	A1
Filing date	Mar 4, 2016
Priority date	Mar 12, 2015
Publication date	Sep 15, 2016
Grant date	—

Abstract

A power tool assembly includes a drop arm assembly rotatably supporting an arbor shaft and movable between a first drop arm position and a second drop arm position, an actuating device configured to transfer a force to the drop arm assembly when the drop arm assembly is at the first drop arm assembly position, a control system configured to control the actuating device to transfer the force to the drop arm assembly when an unsafe condition is sensed, a motor operably connected to the arbor shaft through a gear, and a gear housing which houses the gear, the gear housing formed from a non-conductive material.

First claim

1 . A power tool assembly comprising:
a drop arm assembly rotatably supporting an arbor shaft and movable between a first drop arm position and a second drop arm position; an actuating device configured to transfer a force to the drop arm assembly when the drop arm assembly is at the first drop arm assembly position; a control system configured to control the actuating device to transfer the force to the drop arm assembly when an unsafe condition is sensed; a motor operably connected to the arbor shaft through a gear; and a gear housing which houses the gear, the gear housing formed from a non-conductive material.

2 . The power tool assembly of claim 1 , wherein the gear housing extends over a fan mounted on a power shaft of the motor.

3 . The power tool assembly of claim 2 , wherein:
the power shaft defines a power shaft axis; and the gear housing further comprises a plurality of radial vents, the radial vents configured to vent air driven by the fan radially outwardly from the axis.

4 . The power tool assembly of claim 3 , wherein the non-conductive material is a plastic.

5 . The power tool assembly of claim 3 , further comprising:
an offset drive shaft operably connected to the power shaft through the gear and located at least partially within the gear housing; and at least one first bearing rotationally supporting the offset drive shaft and located within the gear housing.

6 . The power tool assembly of claim 5 , further comprising:
a cover plate enclosing the gear within the gear housing, the cover plate made from a non-conductive material.

7 . The power tool assembly of claim 6 , further comprising:
at least one second bearing rotationally supporting the offset drive shaft, the at least one second bearing directly supported by the cover plate.

8 . A power tool assembly comprising:
a drop arm assembly rotatably supporting an arbor shaft; a control system configured to place the drop arm assembly in a safe condition when an unsafe condition is sensed; a motor including a power shaft operably connected to the arbor shaft; and a housing partially enclosing the motor, the housing including a plurality of radial vents, the radial vents configured to vent air radially outwardly from an axis defined by the power shaft.

9 . The housing of claim 8 , wherein the housing is formed from a non-conductive material.

10 . The power tool assembly of claim 9 , wherein the housing extends over a fan mounted on the power shaft of the motor.

11 . The power tool assembly of claim 10 , wherein the non-conductive material is a plastic.

12 . The power tool assembly of claim 10 , further comprising:
an offset drive shaft operably connected to the power shaft through a gear and located at least partially within the housing; and at least one first bearing rotationally supporting the offset drive shaft and located within the housing.

13 . The power tool assembly of claim 12 , further comprising:
a cover made from a non-conductive material; and at least one second bearing rotationally supporting the offset drive shaft, the at least one second bearing directly supported by the cover plate.

14 . The power tool assembly of claim 13 , further comprising:
a gear operably connected to the arbor shaft and the power shaft, the gear housed by the housing.

Assignees

• Bosch Tool Corp
• Bosch Gmbh Robert

Inventors

• Doumani Robert S
• Laliberte Eric

Classifications

• B23D47/12

  of drives for circular saw blades · CPC title

• B23D47/08

  of devices for bringing the circular saw blade to the workpiece or removing same therefrom · CPC title

• B23D59/002 Primary

  for the position of the saw blade (mounting for swiveling or tilting a circular saw blade B27B5/36; portable power-driven circular saws with adjustment for cutting depth or amount of tilting B27B9/02) · CPC title

• B23D45/067 Primary

  the saw blade being adjustable according to depth or angle of cut · CPC title

• B27G19/02

  for circular saws · CPC title