U.S. patent application number 11/088690 was filed with the patent office on 2005-10-20 for power tool.
This patent application is currently assigned to Positec Power Tools (Suzhou) Co., Ltd.. Invention is credited to Wu, Haiquan.
Application Number | 20050230134 11/088690 |
Document ID | / |
Family ID | 34669993 |
Filed Date | 2005-10-20 |
United States Patent
Application |
20050230134 |
Kind Code |
A1 |
Wu, Haiquan |
October 20, 2005 |
Power tool
Abstract
A power tool comprising a rotary motor disposed in a housing, a
transmission mechanism attached to the rotary shaft of the rotary
motor and a fan disposed on the rotary motor. The housing near to
the fan defines a first air discharge port. The housing outside the
transmission mechanism defines a second air discharge port. An
inner wall of the housing between the first air discharge port and
the transmission mechanism forms an air baffle. Cooling air may
flow from the air baffle to the second air discharge port outside
the transmission mechanism to cool the transmission mechanism.
Inventors: |
Wu, Haiquan; (Suzhou,
CN) |
Correspondence
Address: |
Parsons Behle & Latimer
201 South Main Street, Suite 1800
P. O. Box 45898
Salt Lake City
UT
84111
US
|
Assignee: |
Positec Power Tools (Suzhou) Co.,
Ltd.
|
Family ID: |
34669993 |
Appl. No.: |
11/088690 |
Filed: |
March 24, 2005 |
Current U.S.
Class: |
173/217 |
Current CPC
Class: |
B25F 5/02 20130101; B25F
5/008 20130101 |
Class at
Publication: |
173/217 |
International
Class: |
E21B 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 25, 2004 |
CN |
200420025748.9 |
Claims
We claim:
1. A power tool comprising: a housing; a rotary motor disposed in
the housing and having a rotary shaft; a transmission mechanism in
engagement with the rotary shaft; a fan for generating an airflow
mounted radially on the rotary motor, wherein the housing near to
the fan defines a first air discharge port for discharging air at
the end of a first flow path and wherein the housing in close
proximity to the transmission mechanism defines a second air
discharge port for discharging air at the end of a second flow
path, wherein an air baffle between the first air discharge port
and the transmission mechanism is adapted to direct air along the
second flow path, wherein the air directed along the second flow
path serves to cool the transmission mechanism in use.
2. The power tool as defined in claim 1 wherein the air baffle is
an elongate interior wall of the housing.
3. The power tool as defined in claim 1 wherein the second air
discharge port is disposed in the housing at a position effectively
coincident with the intersection of the axis of the rotary motor
and the axis of the transmission mechanism.
4. The power tool as defined in claim 1 wherein the second air
discharge port is a plurality of discrete air vents which are
disposed circumferentially in the housing in close proximity to the
transmission mechanism.
5. The power tool as defined in claim 4 wherein the discrete air
vents are substantially evenly disposed circumferentially in the
housing in close proximity to the transmission mechanism.
6. The power tool as defined in claim 4 wherein the discrete air
vents are disposed circumferentially in the housing in a plane
containing the intersection of the axis of the rotary motor and the
axis of the transmission mechanism.
7. The power tool as defined in claim 4 wherein the discrete air
vents are disposed circumferentially in the housing in a plane
substantially containing the axis of the air baffle.
8. The power tool as defined in claim 1 wherein the first discharge
port is disposed in at least a part of a portion of the housing
which is substantially coplanar with the fan.
9. The power tool as defined in claim 1 wherein the first air
discharge port is disposed in at least a part of a portion of the
housing which is substantially coaxial with the fan.
10. The power tool as defined in claim 1 wherein the first air
discharge port skirts the fan.
11. The power tool as defined in claim 1 wherein the transmission
mechanism comprises: a rotary gear wheel intermeshed with the
rotary shaft; and an elongate output shaft extending from the
rotary gear wheel to a cutting element.
12. The power tool as defined in claim 11 wherein the elongate
output shaft is downstream from the rotary gear wheel in the second
flow path.
13. The power tool as defined in claim 11 wherein the second air
discharge port is disposed in at least a part of a portion of the
housing which is substantially coplanar with the elongate output
shaft.
14. The power tool as defined in claim 11 wherein the second air
discharge port is disposed in at least a part of a portion of the
housing which is substantially coaxial with the elongate output
shaft.
15. The power tool as defined in claim 11 wherein the second air
discharge port skirts the elongate output shaft.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Priority is claimed to Application Serial No. 200420025748.9
filed on Mar. 25, 2004 in the People's Republic of China.
FIELD OF THE INVENTION
[0002] The present invention relates to a power tool having a novel
cooling arrangement.
BACKGROUND OF THE INVENTION
[0003] A conventional power tool has a fan disposed near to the
motor so that the motor is easily cooled. However, in some power
tools, the axis of the motor and the axis of the working piece form
a certain angle which makes the transmission mechanism difficult to
cool thereby resulting in the transmission mechanism reaching a
high temperature during use.
SUMMARY OF THE INVENTION
[0004] An object of the present invention is to provide a power
tool in which a fan may cool not only the motor but also the
transmission mechanism.
[0005] Viewed from a first aspect the present invention provides a
power tool comprising: a housing; a rotary motor disposed in the
housing and having a rotary shaft; a fan for generating an airflow
mounted radially on the rotary motor, wherein the housing near to
the fan defines a first air discharge port for discharging air at
the end of a first flow path and wherein the housing in close
proximity to the transmission mechanism defines a second air
discharge port for discharging air at the end of a second flow
path, wherein an air baffle between the first air discharge port
and the transmission mechanism is adapted to direct air along the
second flow path, wherein the air directed along the second flow
path serves to cool the transmission mechanism in use.
[0006] To fulfill the object of the invention, the power tool in an
embodiment comprises a motor disposed in a housing, a transmission
mechanism attached to the rotary shaft of the motor and a fan
disposed on the motor. The housing near to the fan defines a first
air discharge port. The housing outside the transmission mechanism
defines a second air discharge port. An inner wall of the housing
between the first air discharge port and the transmission mechanism
forms an air baffle.
[0007] The air baffle and the second air discharge port
advantageously define a second flow path for cooling air generated
by the fan to cool the transmission device.
[0008] The housing typically consists of a motor-containing part
contiguous with a transmission mechanism-containing part. The axis
of the motor-containing part may be substantially perpendicular to
the axis of the transmission mechanism-containing part. The first
air discharge port may be contained in the motor-containing part.
The second air discharge port may be contained in the transmission
mechanism-containing part. The transmission mechanism-containing
part may be multiply ribbed. The motor-containing part is adapted
externally to be used as a handle. The transmission
mechanism-containing part is adapted at an end to mount the cutting
element externally.
[0009] Preferably the air baffle is an elongate interior wall of
the housing.
[0010] Preferably the second air discharge port is disposed in the
housing at a position effectively coincident with the intersection
of the axis of the rotary motor and the axis of the transmission
mechanism.
[0011] Preferably the second air discharge port is a plurality of
discrete air vents which are disposed circumferentially in the
housing in close proximity to the transmission mechanism.
Particularly preferably the discrete air vents are substantially
evenly disposed circumferentially in the housing in close proximity
to the transmission mechanism. In this embodiment, the cooling air
advantageously flows out uniformly from the second air discharge
port and carries away heat from the transmission mechanism
evenly.
[0012] Particularly preferably the discrete air vents are disposed
circumferentially in the housing in a plane containing the
intersection of the axis of the rotary motor and the axis of the
transmission mechanism.
[0013] Particularly preferably the discrete air vents are disposed
circumferentially in the housing in a plane substantially
containing the axis of the air baffle. Particularly preferably the
discrete air vents are each disposed at the end of an axial rib in
the exterior surface of the housing.
[0014] Preferably the first discharge port is disposed in at least
a part of a portion of the housing which is substantially coplanar
with the fan.
[0015] Preferably the first air discharge port is disposed in at
least a part of a portion of the housing which is substantially
coaxial with the fan.
[0016] Preferably the first air discharge port skirts the fan.
[0017] In a preferred embodiment, the transmission mechanism
comprises: a rotary gear wheel intermeshed with the rotary shaft;
and an elongate output shaft extending from the rotary gear wheel
to a cutting element. Typically the angle between the axis of the
rotary motor and the axis of the cutting element (and the
transmission mechanism) is obtuse.
[0018] Preferably the elongate output shaft is downstream from the
rotary gear wheel in the second flow path.
[0019] Preferably the second air discharge port is disposed in at
least a part of a portion of the housing which is substantially
coplanar with the elongate output shaft.
[0020] Preferably the second air discharge port is disposed in at
least a part of a portion of the housing which is substantially
coaxial with the elongate output shaft.
[0021] Preferably the second air discharge port skirts the elongate
output shaft.
[0022] The first air discharge port may be a grille or mesh.
[0023] The fan may be mounted coaxially on the rotary motor.
[0024] Typically the air baffle extends from the first air
discharge port to the second air discharge port. The axis of the
air baffle may be substantially parallel to the axis of the
motor-containing part of the housing.
[0025] The power tool may be a power drill or the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a perspective view of an embodiment of the power
tool of the present invention;
[0027] FIG. 2 is a partial view of the internal structure of the
embodiment of the power tool of the present invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0028] Referring to FIGS. 2 and 2, a power tool comprises generally
a housing 3, a rotary motor 9 disposed in the housing 3 and a
transmission mechanism 8 attached to a rotary shaft of the rotary
motor 9. The transmission mechanism 8 comprises a rotary gear wheel
8a intermeshed with the rotary shaft and an elongate output shaft 7
extending from the rotary gear wheel 8a to a cutting element (not
shown). The angle between the axis of the rotary motor 9 and the
axis of the cutting element is obtuse.
[0029] The housing consists of a motor-containing part 3b
contiguous with a transmission mechanism-containing part 3a which
is multiply ribbed. The motor-containing part 3b is adapted
externally to be used as a handle. The transmission
mechanism-containing part 3a is adapted at an end 300 to mount the
cutting element externally.
[0030] A fan 2 is integrally and coaxially disposed on the rotary
motor 9. The housing 3 near to the fan 2 defines a first air
discharge port 1 in the form of a grille contained in the
motor-containing part 3b and the housing 3 defines a second air
discharge port 4 contained in the transmission mechanism-containing
part 3a outside the transmission mechanism 8. Referring to FIG. 1,
the second discharge port 4 is a plurality of discrete air vents
evenly arranged at the end of an axial rib in the housing 3 outside
the transmission mechanism 8.
[0031] An inner wall of the housing 3 between the first air
discharge port 1 and the transmission mechanism 8 forms an air
baffle 6. The air baffle 6 serves to direct air along a path from
the fan 2 to the second air discharge port 4.
[0032] During operation of the power tools, the rotary motor 9 is
readily cooled due to the close proximity of the fan 2 and of the
first air discharge port 1. Meanwhile, the flow of cooling air from
the fan 2 to the second air discharge port 4 cools the transmission
mechanism 8.
* * * * *