Power tool having improved motor and controller cooling

• US 9,718,180 B2
• Filed: 05/07/2014
• Issued: 08/01/2017
• Est. Priority Date: 05/09/2013
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Miller, Matthew, Gallagher, William F., Hester, Russell D.
• Primary Examiner(s): CHUKWURAH, NATHANIEL C
• Application Number:
  US14/271,728
• Publication Number:
  US 20140338948A1
• Time in Patent Office: 1,182 Days
• Field of Search: 173 48, 173117, 173217, 173216, 173170, 173171, 310 47, 310 50
• CPC Class Codes: B25F 5/008 Cooling means
• CPC Class Codes: B25F 5/02 Construction of casings, bodies or handles B25F5/006, B25F5/008 take precedence
• CPC Class Codes: H02K 7/145 Hand-held machine tool
• CPC Class Codes: H02K 9/06 with fans or impellers driven by the machine shaft

Abstract

A power tool includes a motor housing defining a first air chamber with a first air inlet that receives a motor. A handle extending from the motor housing defines a second air chamber with a second air inlet that receives an electronics control module. A third air chamber with an air outlet receives a fan coupled to the motor output shaft. The fan: (a) pulls a first ambient airstream through the first air chamber from the first air inlet and into the third air chamber, bypassing the second air chamber, to cool the motor; (b) pulls a second ambient airstream through the second air chamber from the second air inlet and into the third air chamber, bypassing the first air chamber, to cool the electronics module; and (c) exhausts the first and second airstreams from the third air chamber via the air outlet.

Claims

1. A power tool comprising:

a housing having a first housing portion defining a first air chamber and a first air inlet, a second housing portion defining a second air chamber and a second air inlet, and a third housing portion defining a third air chamber and an air outlet;

a motor disposed in the first housing portion;

an electronics module disposed in the second housing portion and electrically connected to the motor;

a fan disposed in the third housing portion, the fan driven by the motor, wherein the fan;

(a) pulls a first ambient airstream through the first air chamber from the first air inlet and into the third air chamber, bypassing the second air chamber, to cool the motor, (b) pulls a second ambient airstream through the second air chamber from the second air inlet and into the third air chamber, bypassing the first air chamber, to cool the electronics module, and (c) exhausts the first ambient airstream and the second ambient airstream from the third air chamber via the air outlet; and

a motor cap secured to a front end of the motor, the motor cap including a generally radial wall disposed between the fan and the motor and defining a first cap inlet in communication with the first air chamber to direct first ambient airstream to the fan, and a generally-cylindrical sidewall defining a second cap inlet in communication with the second air chamber to direct air to direct second ambient airstream to the fan.

2. The power tool of claim 1, wherein the first air chamber is at least partially defined by an outer wall of the first housing portion, and in internal wall separating the first air chamber from the second air chamber.

3. The power tool of claim 2, wherein the internal wall defines a valve that opens when pressure in the second air chamber exceeds pressure in the first air chamber by a predetermined threshold amount, to allow the fan to pull the second ambient airstream through the first air chamber into the third air chamber to cool the motor.

4. The power tool of claim 2, wherein the generally-cylindrical sidewall of the motor cap at least partially contains the fan.

5. The power tool of claim 1, wherein the first housing portion comprises a rear portion of a motor housing, the second housing portion comprises a handle extending transverse to the motor housing, and the third housing portion comprises a front portion of the motor housing.

6. The power tool of claim 5, further comprising an internal wall separating the first housing portion from the second housing portion.

7. The power tool of claim 5, wherein the second air chamber is at least partially defined by a converging channel formed in the handle that converges from a wider dimension adjacent the second air inlet and a narrower dimension adjacent the third air chamber.

8. The power tool of claim 7, wherein the handle has a front portion facing a front end of the power tool, a rear portion facing a rear end of the power tool, and two lateral side portions joining the front portion and the rear portion, the third air chamber at least partially defined by a converging channel formed only in one of the lateral side portions and receiving the heat sink.

9. The power tool of claim 5, wherein the electronics module is coupled to a heat sink received the second air chamber.

10. The power tool of claim 9, wherein the heat sink comprises a folded metal plate.

11. A power tool comprising:

a motor housing defining a first air chamber with a first air inlet, and a third air chamber with an air outlet;

a handle coupled to and extending from the motor housing, the handle defining a second air chamber with a second air inlet away from the motor housing;

a motor disposed in the first air chamber;

an electronics module disposed in the handle and electrically connected to the motor;

a fan disposed in the third air chamber, the fan driven by the motor, wherein the fan;

(a) pulls a first ambient airstream through the first air chamber from the first air inlet and into the third air chamber, bypassing the second air chamber, to cool the motor, (b) pulls a second ambient airstream through the second air chamber from the second air inlet and into the third air chamber, bypassing the first air chamber, to cool the electronics module, and (c) exhausts the first ambient airstream and the second ambient airstream from the third air chamber via the air outlet; and

a motor cap secured to a front end of the motor, the motor cap including a generally radial wall disposed between the fan and the motor and defining a first cap inlet in communication with the first air chamber to direct first ambient airstream to the fan, and a generally-cylindrical sidewall defining a second cap inlet in communication with the second air chamber to direct air to direct second ambient airstream to the fan.

12. The power tool of claim 11, further comprising in internal wall separating the first air chamber from the second air chamber.

13. The power tool of claim 12, wherein the internal wall defines a valve that opens when pressure in the second air chamber exceeds pressure in the first air chamber by a predetermined threshold amount, to allow the fan to pull the second ambient airstream through the first air chamber into the third air chamber to cool the motor.

14. A power tool comprising:

a housing having a first housing portion and a second housing portion;

a motor disposed in the first housing portion and having a motor shaft;

an electronics module disposed in the second housing portion and electrically connected to the motor;

a fan mounted on the motor shaft and driven by the motor; and

a motor cap secured to a front end of the motor, the motor cap including a generally radial portion disposed between the fan and the motor and defining at least one axial air inlet that allows entry of a first ambient airstream from the first housing portion to the fan, and a generally-cylindrical portion defining a radial air inlet that allows entry of a second air chamber from the second housing portion to the fan bypassing the first housing portion.

15. The power tool of claim 14, wherein radial portion of the motor cap defines a hole for receiving the motor shaft therein, the motor shaft being secured inside the hole via a bushing.

16. The power tool of claim 14, wherein the at least one axial air inlet comprises a plurality of inlet slots circumferentially arranged around a center portion of the motor cap.

17. The power tool of claim 16, wherein radial air inlet is arranged to direct air through at least one of the plurality of inlet slots towards the fan.

18. The power tool of claim 14, wherein the generally-cylindrical portion of the motor cap comprises at least one axially-extending arcuate portion that produce over an outer portion of the motor.