U.S. patent application number 13/683925 was filed with the patent office on 2013-05-23 for cooling jacket.
This patent application is currently assigned to DELTA ELECTRONICS, INC.. The applicant listed for this patent is Delta Electronics, Inc.. Invention is credited to Hung-Chi LO, Hong-Cheng SHEU.
Application Number | 20130126143 13/683925 |
Document ID | / |
Family ID | 48425678 |
Filed Date | 2013-05-23 |
United States Patent
Application |
20130126143 |
Kind Code |
A1 |
SHEU; Hong-Cheng ; et
al. |
May 23, 2013 |
COOLING JACKET
Abstract
A cooling jacket for cooling an electric motor is provided. The
cooling jacket has one or more continuous S-shaped pipes, covering
the electric motor, for conducting working fluid, wherein each
continuous S-shaped pipe at least has: a forwarding portion and a
reversed portion, respectively extending along two circumferential
directions which are parallel but opposite to each other; and a
turning portion connected between the forwarding portion and the
reversed portion.
Inventors: |
SHEU; Hong-Cheng; (Taoyuan
Hsien, TW) ; LO; Hung-Chi; (Taoyuan Hsien,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Delta Electronics, Inc.; |
Taoyuan Hsien |
|
TW |
|
|
Assignee: |
DELTA ELECTRONICS, INC.
Taoyuan Hsien
TW
|
Family ID: |
48425678 |
Appl. No.: |
13/683925 |
Filed: |
November 21, 2012 |
Current U.S.
Class: |
165/177 |
Current CPC
Class: |
F28F 1/04 20130101; H02K
5/20 20130101; H02K 9/19 20130101; F28F 1/00 20130101 |
Class at
Publication: |
165/177 |
International
Class: |
F28F 1/00 20060101
F28F001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 23, 2011 |
TW |
100142813 |
Claims
1. A cooling jacket for cooling an electric motor comprising: one
or more continuous S-shaped pipes, covering the electric motor, for
conducting working fluid, wherein each continuous S-shaped pipe at
least comprises: a forwarding portion and a reversed portion,
respectively extending along two respective circumferential
directions which are parallel but opposite to each other; and a
turning portion connected between the forwarding portion and the
reversed portion.
2. The cooling jacket as claimed in claim 1, wherein the forwarding
portions and/or the reversed portions of the continuous S-shaped
pipe have unequal pipe diameters.
3. The cooling jacket as claimed in claim 2, wherein the pipe
diameter of the continuous S-shaped pipe reduces from a working
fluid inlet to a working fluid outlet.
4. The cooling jacket as claimed in claim 1, wherein the cooling
jacket has N sets of the continuous S-shaped pipes, and each set of
the continuous S-shaped pipe covers a part of the electric
motor.
5. The cooling jacket as claimed in claim 1, wherein the cooling
jacket has N sets of the continuous S-shaped pipes, and each set of
the continuous S-shaped pipe covers 1/N of the circumference of the
electric motor.
6. The cooling jacket as claimed in claim 1, wherein the cooling
jacket has two sets of the continuous S-shaped pipes, and the
starting ends of the two sets of the continuous S-shaped pipes
share a working fluid inlet.
7. The cooling jacket as claimed in claim 1, wherein the cooling
jacket has two sets of the continuous S-shaped pipes, and the
terminating ends of the two sets of the continuous S-shaped pipes
share a working fluid outlet.
8. The cooling jacket as claimed in claim 1, wherein the flowing
directions of the working fluid in any two sets of the continuous
S-shaped pipes are opposite to each other.
9. The cooling jacket as claimed in claim 1, further comprising a
first continuous S-shaped pipe having a first forwarding portion, a
first reversed portion and a first turning portion; and a second
continuous S-shaped pipe having a second forwarding portion, a
second reversed portion and a second turning portion, wherein each
of the first forwarding, reversed and turning portions is
respectively juxtaposed to the second forwarding, reversed and
turning portions.
10. The cooling jacket as claimed in claim 1, wherein each set of
the continuous S-shaped pipes covers a different circumference of
the electric motor.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Non-provisional application claims priority under 35
U.S.C. .sctn.119(a) on Patent Application No(s). 100142813, filed
in Taiwan, Republic of China on Nov. 23, 2011, the entire contents
of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to heat dissipation technology
for electric motor.
[0004] 2. Description of the Related Art
[0005] To maintain the performance and prolong the lifecycle of an
electric motor, the heat generated from a operating electric motor
should be appropriately dissipated.
[0006] The prior art usually uses a cooling pipe and the working
fluid that flows through the cooling pipe to dissipate the heat
generated from the electric motor. FIG. 1 is a schematic diagram of
the cooling pipe in the prior art. In FIG. 1, the electric motor
(not shown) is basically in a column shape, and, to fit the shape
of the electric motor, the cooling pipe extends in a spiral fashion
from an inlet to an outlet and covers the electric motor. From this
diagram, it can be seen that the cooling pipe does not cover the
areas A and B of the electric motor which is near the inlet and
outlet of the cooling pipe, thus causing heat concentration in the
areas A and B and influencing the entire heat dissipation of the
electric motor. Although in some designs the cooling pipe can cover
these areas, the working fluid usually loses its kinetic energy
when flowing through these areas due to the poor convective heat
transfer ability of the fluid in a spiral pipe (from the principles
of fluid dynamics, the fluid in the spiral pipe has little pressure
drop, which leads to a low convective heat transfer rate and poor
convective heat transfer ability)
[0007] It can be noted that the heat dissipating area provided by
the cooling pipe and the quantity of the working fluid that flows
in the cooling pipe are both limited to the size of the electric
motor. Therefore, how to design a cooling device to dissipate more
heat in the limited regions is an important issue which needs to be
solved.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention provides a cooling jacket for cooling
an electric motor. The cooling jacket comprises one or more
continuous S-shaped pipes, covering the electric motor, for
conducting working fluid, wherein each continuous S-shaped pipe at
least comprises: a forwarding portion and a reversed portion,
respectively extending along two circumferential directions which
are parallel but opposite to each other; and a turning portion
connected between the forwarding portion and the reversed
portion.
[0009] A detailed description is given in the following embodiments
with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention can be more fully understood by
reading the subsequent detailed description and examples with
references made to the accompanying drawings, wherein:
[0011] FIG. 1 is a schematic diagram of the cooling pipe in the
prior art.
[0012] FIG. 2A is a three dimensional (3D) view of the cooling
jacket according to an embodiment of the present invention. FIG. 2B
is an illustrative diagram where the cooling jacket in FIG. 2A is
spread into a plane for easy comprehension.
[0013] FIG. 3A is a 3D view of the cooling jacket according to an
embodiment of the present invention. FIG. 3B is an illustrative
diagram where the cooling jacket in FIG. 3A is spread into a
plane.
[0014] FIG. 4A is a 3D view of the cooling jacket according to an
embodiment of the present invention. FIG. 4B is an illustrative
diagram where the cooling jacket in FIG. 4A is spread into a
plane.
[0015] FIGS. 5A and 5B shows three sets of continuous S-shaped
pipes in a cooling jacket 500.
[0016] FIG. 6A is a 3D view of the cooling jacket according to an
embodiment of the present invention.
[0017] FIG. 6B is an illustrative diagram where the cooling jacket
in FIG. 4A is "spread" into a 2D plane.
[0018] FIG. 7A is a 3D view of the cooling jacket according to an
embodiment of the present invention.
[0019] FIG. 7B is an illustrative diagram where the cooling jacket
in FIG. 4A is "spread" into a 2D plane.
[0020] FIG. 8 is a schematic diagram of a two-layered cooling
jacket according to an embodiment of the present invention.
[0021] FIG. 9 shows a combination of the cooling jackets in FIGS.
6A and 7.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The following description is of the best-contemplated mode
of carrying out the invention. This description is made for the
purpose of illustrating the general principles of the invention and
should not be taken in a limiting sense. The scope of the invention
is best determined by reference to the appended claims.
[0023] FIG. 2A is a 3D view of the cooling jacket according to an
embodiment of the present invention. FIG. 2B is an illustrative
diagram where the cooling jacket in FIG. 2A is "spread" into a 2D
plane for easy comprehension. Although the cooling jacket of the
present invention is originally designed for high-power and
high-accuracy electric motors such as motors and power generators,
the present invention should not be limited thereto. As shown in
FIGS. 2A and 2B, the cooling jacket 200, in addition to the working
fluid inlet 240 and working fluid outlet 250, further comprises
"one set" of continuous S-shaped pipe (embodiments with several
sets of continuous S-shaped pipes will be discussed later). The set
of continuous S-shaped pipe covers the entire electric motor, and
allows the working fluid to flow through the pipe. Thus, the heat
generated from the electric motor can be dissipated by the flow of
the working fluid, and the electric motor can be kept at a normal
operating temperature. Generally, the working fluid of the present
invention can be any kind of liquid which has temperature not
higher than the normal operating temperature of the electric motor.
For example, the liquid can be water, lubricant oil, mixed liquid
of 50% ethylene glycol and 50% water, or water with anti-freeze
agent, however the present invention should not be limited thereto.
In addition, the liquid in the cooling jacket of the present
invention can be propelled by various motors or pumps (not shown in
Figs.). The purpose of the present invention is to overcome defects
in heat dissipation in the prior art due to limited cooling area
and limited working fluid quantity. The present invention achieves
this purpose by increasing the flow speed of the working fluid
(given the same propelling power as that in the prior art). The
principle of the present invention will be further described in
detail later.
[0024] In comparison between FIGS. 1 and 2A, it can be seen that
the cooling jacket of the present invention has a quite different
structure from that in the prior art. The cooling pipe described in
"Description of the Related Art" is in a spiral shape, but the
cooling pipe of the present invention is substantially in a
continuous S shape. For illustration, the continuous S-shaped piped
cooling jacket 200 of the present invention can be divided into
three parts: the forwarding portion(s) 210, the reversed portion(s)
220 and the turning portion(s) 230. In order to cover as much of
the electric motor as possible, the forwarding portion 210 and the
reversed portion 220 are juxtaposed (parallel) to each other, and
both extend along a circumferential direction. In addition, the
forwarding portion 210 and the reversed portion 220 respectively
extend in opposite directions (where the forwarding portion 210
extends clockwise, while the reversed portion 220 extends
counter-clockwise), thus allowing the working fluid to flow in
opposite directions. The turning portion 230 of the present
invention is connected between the forwarding portion 210 and the
reversed portion 220 for turning the working fluid 180 degrees. The
major difference between the prior art and the present invention is
the turning portion 230. In the present invention, the working
fluid has a great pressure drop when flowing through the turning
portion 230, thus increasing the flow speed as well as the
convective heat transfer rate (h value, in the unit of W/m2k)
there. Since the heat exchanged between the cooling flow and the
electric motor is basically in direct proportion to the convective
heat transfer rate, the cooling jacket of the present invention can
greatly improve the defects of the heat concentration around the
inlets and outlet of the spiral shaped cooling pipes in the prior
art (as shown in FIG. 1).
[0025] FIG. 3A is a 3D view of the cooling jacket according to an
embodiment of the present invention. FIG. 3B is an illustrative
diagram where the cooling jacket in FIG. 3A is "spread" into a 2D
plane. In FIG. 3B, the continuous S-shaped pipe of the cooling
jacket 300 has substantially the same structure as that in FIG. 2B,
and can be divided into three parts: the forwarding portion(s) 310,
the reversed portion(s) 320 and the turning portion(s) 330.
However, different from FIG. 2B, the continuous S-shaped pipe in
FIG. 3B has an unequal pipe diameter. Specifically, the pipe
diameter of the forwarding and the reversed portions of the
continuous S-shaped pipe reduce from the working fluid inlet 340 to
the working fluid outlet 350. In a traditional cooling pipe, as
flowing in a long path, the working fluid will gradually absorb
heat, raise its temperature, and decrease the heat transfer rate.
The purpose of this embodiment is to increase the flow speed as
well as the convective heat transfer rate of the working fluid and
prevent the heat concentration at the ends of the pipes by
gradually reducing the pipe diameter. Although a pipe with
decreasing pipe diameter is described in this embodiment, the
present invention should not be limited thereto. In other
embodiments, in order to achieve the best heat dissipating result,
the pipe diameter of each section of the continuous S-shaped pipe
of the present invention can be varied according to the heat
distribution pattern of the electric motor.
[0026] FIG. 4A is a 3D view of the cooling jacket according to an
embodiment of the present invention. FIG. 4B is an illustrative
diagram where the cooling jacket in FIG. 4A is "spread" into a 2D
plane. In FIG. 4B, the continuous S-shaped pipe of the cooling
jacket 300 has substantially the same structure as that in FIG. 2B,
and can be divided into three parts: the forwarding portion(s) 410,
the reversed portion(s) 420 and the turning portion(s) 430.
However, unlike in FIG. 2B, the cooling jacket 400 in FIG. 4B has
"two" sets of continuous S-shaped pipes 400L and 400R. For
illustration, the two sets of the continuous S-shaped pipes 400L
and 400R have the same size (the total length of the pipe 400L or
400R is half of that in FIG. 2B), and each pipe 400L or 400R covers
half of the circumference of the electric motor. However, in other
embodiments, these two continuous S-shaped pipes may have different
sizes and cover a different area of the electric motor. Compared
with the embodiment in FIG. 2B (given that the working fluid has
the same temperature at the working fluid inlet in both embodiments
of FIGS. 2B and 4B), the working fluid in FIG. 4B flows through a
much shorter length before being expelled, thus removing heat from
the electric motor more rapidly. It should be noted that the
cooling jacket of the present invention may have any number of sets
of continuous S-shaped pipes. Specifically, the cooling jacket may
have two or more continuous S-shaped pipes. For example, the
cooling jacket may have N sets of the continuous S-shaped pipes for
respectively covering 1/N of the circumference of the electric
motor. FIGS. 5A and 5B show three sets of continuous S-shaped pipes
in a cooling jacket 500. Since those skilled in the art can easily
understand the structural features of the cooling jacket 500, it
will not be described in detail.
[0027] FIG. 6A is a 3D view of the cooling jacket according to an
embodiment of the present invention. FIG. 6B is an illustrative
diagram where the cooling jacket in FIG. 4A is "spread" into a 2D
plane. The cooling jacket 600 in FIGS. 6A and 6B also has two sets
of continuous S-shaped pipes 600E and 600I. However, the turning
portions 630E and 630I of the continuous S-shaped pipes 600E and
600I have different overall lengths. As shown in FIG. 6B, the
turning portion 630E of the continuous S-shaped pipe 600E is
connected to the forwarding portion 610E at an angle of 90 degrees.
It extends along the axis direction of the electric motor for a
short distance L, and is connected to the reversed portion 620E at
another angle of 90 degrees. The turning portion 630I of the pipe
600I is juxtaposed with the turning portion 630E of the pipe 600E.
In this better embodiment, the working fluid inlets 640E of the
pipes 600E and working fluid inlets 640I of the pipes 600I may be
on two opposite sides of the cooling jacket 600 so that the working
fluid in the pipes 600E and 600I can flow in two opposite
directions. The purpose of this manner is to further even the heat
distribution of the electric motor, thus preventing the heat
concentration at the ends of the cooling jacket.
[0028] FIG. 7A is a 3D view of the cooling jacket according to an
embodiment of the present invention. FIG. 7B is an illustrative
diagram where the cooling jacket in FIG. 4A is "spread" into a 2D
plane. Similarly, the cooling jacket 700 in FIG. 7B has two sets of
continuous S-shaped pipes 700R and 700L, and each has the
forwarding portions 710, the reversed portions 720 and the turning
portions 730. However, different from that in FIG. 4B, the two
pipes 700R and 700L are in a mirrored arrangement, and share the
same starting end, i.e., the working fluid inlet 740, and the same
terminating end, i.e., the working fluid outlet 750. The cooling
jacket 700 overcomes the defects of heat concentration around the
ends of the spiral shaped pipes in the prior art, and evens the
heat distribution of the electric motor.
[0029] FIG. 8 is a schematic diagram of a two-layered cooling
jacket according to an embodiment of the present invention. The
cooling jacket 800 has an inner layer L1 and an outer layer L2,
where each layer may have continuous S-shaped pipes having the same
structure as, or similar structure to, those described above. The
inner layer L1 and the outer layer L2 are respectively disposed at
different circumferences of the electric motor (having different
radiuses). In some embodiments, each layer has its own and
dependent working fluid inlet and outlet. In some embodiments, the
inlets of the two layers may be disposed at opposite sides of the
cooling jacket to make the working fluid in the layers flow in
opposite directions for preventing heat concentration and improving
heat dissipation. Note that the two-layered cooling jacket is
merely for illustration, the present invention should not be
limited to any number of layers.
[0030] Those skilled in the art can modify and the combine the
cooling jackets in the previous embodiments according to the spirit
of the present invention. For example, FIG. 9 shows a combination
of the cooling jackets in FIGS. 6A and 7, where the arrangement for
the two sets of continuous S-shaped pipes is like that in FIG. 6A
but the arrangement for the inlets and outlets is like that in FIG.
7. The cooling jacket 900 in FIG. 9 can prevent the heat
concentration around the ends of the pipe, but has better heat
distribution than the cooling jacket 600 in FIG. 6A. Since the
cooling jacket of the present invention has various modifications
and combinations, they will not be further discussed.
[0031] While the invention has been described by way of example and
in terms of the preferred embodiments, it is to be understood that
the invention is not limited to the disclosed embodiments. On the
contrary, it is intended to cover various modifications and similar
arrangements (as would be apparent to those skilled in the art).
Therefore, the scope of the appended claims should be accorded the
broadest interpretation so as to encompass all such modifications
and similar arrangements.
* * * * *