Power tool cooling

• US 20060144602A1
• Filed: 12/29/2005
• Published: 07/06/2006
• Est. Priority Date: 12/23/2004
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Kunz, Michael, Soika, Martin, Benner, Erhard, Arich, Klaus-Dieter, Droste, Manfred, Nemetz, Uwe
• Granted Patent: US 7,705,497 B2
• Time in Patent Office: Days
• US Class Current: 173/109
• CPC Class Codes: B25D 16/00 Portable percussive machines with superimposed rotation , the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit combined percussion and rotary drilling adapted for earth drilling E21B6/00
• CPC Class Codes: B25D 17/20 Devices for cleaning or cooling tool or work
• CPC Class Codes: B25D 2211/003 Crossed drill and motor spindles
• CPC Class Codes: B25D 2217/0061 related to cooling

Abstract

A power tool cooling system comprises a cooling fan disposed on a motor in a position between the upper field coil and the lower commutator. A transmission housing encapsulates the transmission mechanism. During operation, the fan is driven by the motor and draws air axially through the motor and expels the air radially outwardly through holes in the outer housing of the motor. This causes air to be drawn in through the air vents formed on the top of a tool housing, in the side of the housing and between the housing and a battery pack. The cool air flows outside of the transmission housing, but inside the tool housing such that air does not pass through the transmission mechanism. A plurality of motor openings are also formed in the outer housing of the motor to enable cool air to pass into the motor to cool the motor.

Claims

1. A power tool comprising:

an outer housing for gripping by a user;

a motor disposed in the outer housing and having an output shaft for actuating a working member of the tool;

a cooling fan adapted to be driven by the motor for causing air to flow past the motor; and

a transmission mechanism adapted to actuate said working member in response to rotation of said output shaft, and having an inner housing for supporting the transmission mechanism in the outer housing, wherein the outer housing has at least one air inlet and at least one air outlet and the cooling fan is adapted to cause air to flow from at least one inlet between said inner and outer housing to said motor.

2. A power tool according to claim 1, wherein the motor comprises a motor housing having a plurality of apertures for permitting the flow of air through the motor.

3. A power tool according to claim 2, wherein the motor housing is connected to the inner housing in a manner sealed against air flow between the motor housing and the inner housing.

4. A power tool according to claim 1, further comprising at least one air inlet disposed on an upper surface of the outer housing, at least one air inlet disposed on a side of the outer housing, and at least one air inlet disposed on the outer housing adjacent a releasable battery pack in use.

5. A power tool according to claim 1, wherein said cooling fan is disposed between a field coil and a commutator of the motor.

6. A power tool according to claim 1, further comprising at least one air outlet disposed on the outer housing forwardly of the motor, and at least one air outlet disposed on the outer housing adjacent a releasable battery pack in use.

7. A power tool according to claim 1, wherein the power tool is a hammer drill.