U.S. patent application number 12/320252 was filed with the patent office on 2009-07-30 for motor-operated fan apparatus.
Invention is credited to Katsuyoshi Kawachi, Hiromi Kawarai, Shiro Nakamura, Shigenori Ohira, Narihito Sano, Kazunori Yamada.
Application Number | 20090191070 12/320252 |
Document ID | / |
Family ID | 40600049 |
Filed Date | 2009-07-30 |
United States Patent
Application |
20090191070 |
Kind Code |
A1 |
Kawachi; Katsuyoshi ; et
al. |
July 30, 2009 |
Motor-operated fan apparatus
Abstract
A motor-operated fan apparatus is made up of a brushless motor
and a centrifugal fan. The brushless motor has: a rotary shaft
vertically disposed on a substrate in a rotatable manner; a stator
disposed coaxially with the rotary shaft; and a rotor integrally
disposed on the rotary shaft. The centrifugal fan has: a disk part
which covers the brushless motor and is fixed to the rotary shaft;
and a multiplicity of vane parts which are disposed so as to be
elongated from an outer edge of the disk part. A ventilation
control member is provided in a space between the rotor and the
disk part to block the air flowing from the substrate side to the
space between the rotor and the disk part.
Inventors: |
Kawachi; Katsuyoshi;
(Saitama-shi, JP) ; Nakamura; Shiro; (Saitama-shi,
JP) ; Ohira; Shigenori; (Saitama-shi, JP) ;
Yamada; Kazunori; (Saitama-shi, JP) ; Kawarai;
Hiromi; (Saitama-shi, JP) ; Sano; Narihito;
(Saitama-shi, JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
1030 15th Street, N.W.,, Suite 400 East
Washington
DC
20005-1503
US
|
Family ID: |
40600049 |
Appl. No.: |
12/320252 |
Filed: |
January 22, 2009 |
Current U.S.
Class: |
417/366 ;
417/423.7 |
Current CPC
Class: |
H02K 7/14 20130101; H02K
9/06 20130101; H02K 29/08 20130101 |
Class at
Publication: |
417/366 ;
417/423.7 |
International
Class: |
F04D 29/58 20060101
F04D029/58; F04D 25/08 20060101 F04D025/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 24, 2008 |
JP |
2008-013741 |
Claims
1. A motor-operated fan apparatus comprising: a brushless motor
having: a rotary shaft vertically disposed on a substrate in a
rotatable manner; a stator disposed coaxially with the rotary
shaft; and a rotor integrally disposed on the rotary shaft so as to
be rotatable about the stator at a given distance to the substrate;
a centrifugal fan having: a disk part which covers the brushless
motor and is fixed to the rotary shaft; and a multiplicity of vane
parts which are disposed so as to be elongated from an outer edge
of the disk part in an axial direction; wherein the rotor has
formed therein an exhaust opening for discharging the air passing
from a substrate side through a clearance between the stator and
the rotor; wherein the disk part has formed therein a ventilation
opening for allowing the air through the exhaust opening to flow
therethrough; and wherein a ventilation control member is provided
in a space between the rotor and the disk part to block the air
flowing from the substrate side to the space between the rotor and
the disk part.
2. The motor-operated fan apparatus according to claim 1, wherein
the ventilation control member is integrally formed with one of the
rotor and the disk part.
3. The motor-operated fan apparatus according to claim 1, wherein
the ventilation control member is disposed to bridge the substrate
side portion of the exhaust opening and the substrate side portion
of the ventilation opening.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is based on and claims priority from
Japanese Application Number 2008-013741, filed on Jan. 24, 2008,
the disclosure of which is hereby incorporated by reference herein
in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a motor-operated (or an
electrically powered) fan apparatus which is provided with an
outer-rotor type of brushless motor and a centrifugal fan with the
brushless motor serving as a driving source.
[0004] 2. Description of the Related Art
[0005] There has conventionally been known a motor-operated fan
apparatus which is provided with an outer-rotor type of brushless
motor, and a centrifugal fan having a disk part to cover the
brushless motor. In the apparatus the rotor of the brushless motor
has formed therein discharge openings for cooling the stator, and
the disk part has formed therein ventilation openings for the air
from the discharge openings to flow therethrough (see, e.g.,
JP-T-2002-540754).
[0006] Recently, there is a tendency to minimize the brushless
motor to be disposed inside the centrifugal fan in order to
decrease the weight of the motor-operated fin apparatus.
[0007] On the other hand, it is necessary to keep the air delivery
force, i.e., an output, at substantially the same level as the
conventional one. Therefore, it was difficult to reduce the size of
the centrifugal fan.
[0008] As a solution, it is conceivable to try to decrease the
weight of the motor-operated fan apparatus only by minimizing the
brushless motor. In this case, however, the space between the rotor
of the brushless motor and the disk part of the centrifugal fan
becomes so large that there is a possibility that the air from the
substrate side is likely to flow into this space.
[0009] A problem will then occur in that the air hardly flows into
the clearance between the rotor and the stator, whereby the stator
cannot be sufficiently cooled.
[0010] Therefore, the invention has a problem of providing a
motor-operated fan apparatus in which the space between the rotor
of the brushless motor and the disk part of the centrifugal fan is
relatively large but in which the cooling of the stator can be
sufficiently performed.
SUMMARY OF THE INVENTION
[0011] According to an aspect of the invention, there is provided a
motor-operated fan apparatus comprising a brushless motor and a
centrifugal fan. The brushless motor has a rotary shaft vertically
disposed on a substrate in a rotatable manner, a stator disposed
coaxially with the rotary shaft, and a rotor integrally disposed on
the rotary shaft so as to be rotatable about the stator at a given
distance to the substrate. The centrifugal fan has a disk part
which covers the brushless motor and is fixed to the rotary shaft,
and a multiplicity of vane parts which are disposed so as to be
elongated from an outer edge of the disk part in an axial
direction. The rotor has formed therein an exhaust opening for
discharging the air passing from a substrate side through a
clearance between the stator and the rotor. The disk part has
formed therein a ventilation opening for allowing the air through
the exhaust opening to flow therethrough. A ventilation control
member is provided in a space between the rotor and the disk part
to block the air flowing from the substrate side to the space
between the rotor and the disk part.
[0012] According to the above-described arrangement, the
ventilation control member can block the flow of air from the
substrate side to the space between the rotor and the disk part.
Therefore, even if the space between the rotor of the brushless
motor and the disk part of the centrifugal fan is relatively large,
it is possible to let the air from the substrate side to be
directed into the clearance between the rotor and the stator. As a
result, the stator can be sufficiently cooled.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a vertical sectional view of a motor-operated fan
apparatus according to the invention.
[0014] FIG. 2 is a vertical sectional view of a modified example of
a motor-operated fan apparatus according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Description will now be made, with reference to the
accompanying drawings, about the best mode of the motor-operated
fan apparatus relating to the invention.
[0016] The motor-operated fan apparatus F of the invention is used
for cooling a radiator, condenser, and the like of a motor vehicle
(not illustrated).
[0017] The motor-operated fan apparatus F is made up, as shown in
FIG. 1, of a brushless motor 10, and a centrifugal fan 20 which is
driven by this brushless motor 10.
[0018] The brushless motor 10 is made up of a rotary shaft 12 which
is vertically disposed from an electrical circuit substrate
(substrate) 11 in a manner to be rotatable; a stator 13 which is
disposed coaxially with the rotary shaft 12; and a rotor 14 which
is integrally disposed on the rotary shaft 12 so as to be rotatable
about the stator 13 with a predetermined clearance to the electric
circuit board 11.
[0019] In other words, this brushless motor 10 is a so-called
outer-rotor type of brushless motor in which the rotor 14, i.e., a
rotary element, is disposed on an outer side of the stator 13,
i.e., a stationary element,
[0020] The electric circuit board 11 is provided with: a wiring
pattern such as a driving circuit, a control circuit, and the like;
and an electrolytic condenser 11a; and the like. The electric
circuit board 11 is housed in the circuit protection casing
11b.
[0021] An upper case 11b' of this circuit protection casing 11b has
formed therein a boss part 11c into which one end part 12a of the
rotary shaft 12 is inserted.
[0022] The rotary shaft 12 is rotatably supported, through bearing
parts 12b, on a shaft support part 11d which rises from the boss
part 11c of the circuit protection casing 11b. According to this
arrangement, the rotary shaft 12 is disposed vertically in a manner
to be rotatable.
[0023] One end part 12a of the rotary shaft 12 inserted into the
circuit protection casing 11b has fixed thereto a sensor magnet 15.
This sensor magnet 15 is so arranged that the rotary position of
the permanent magnet 14a of the rotor 14 (to be described
hereinafter) can be detected in cooperation with a Hall device (not
illustrated) mounted on the electric circuit substrate 11.
[0024] The stator 13 is made up of a core 13a which is made by
laminating metallic thin plates, and a coil 13b which is wound
around the core 13a.
[0025] The core 13a is fixed to an outer periphery of the shaft
holding part lid which supports the rotary shaft 12 in a rotatable
manner through the bearing parts 12b. As a result, the stator 13 is
disposed coaxially with the rotary shaft 12.
[0026] The rotor 14 is made up of permanent magnets 14a, 14a, . . .
which are disposed in close proximity to the outside of the stator
13; and a yoke 14b which holds these permanent magnets 14a, 14a, .
. . and which is also fixed to the rotary shaft 12 while covering
or enclosing the stator 13.
[0027] The yoke 14b is made up of a cylindrical main body part 16a;
a closing end part 16b which closes one end of the main body part
16a; and an inclined surface part 16c which is inclined in a manner
to chamfer the main body part 16a and the closing end part 16b.
[0028] The yoke 14b is so arranged that the central portion 16b' of
the closing end part 16b is fixed to the rotary shaft 12 in a state
in which the open end 17, which is the other end of the main body
part 16a, faces the circuit protection casing 11b and with a
predetermined clearance thereto.
[0029] The closing end part 16b and the inclined surface part 16c
have formed therein a plurality of exhaust openings 18.
[0030] The exhaust openings 18 are portions through which is
exhausted or discharged the air flowing from the open end 17 of the
yoke 14b, which corresponds to the side of the electric circuit
substrate 11, to the clearance between the stator 13 and the rotor
14. In other words, the air passing through the inside of the yoke
14b flows through the exhaust openings 18.
[0031] On the other hand, a plurality of permanent magnets 14a are
mounted on an inner circumference of the main body part 16a
enclosing the stator 13, in a state in which different magnetic
poles are alternately arranged in the circumferential
direction.
[0032] According to this arrangement, the rotor 14 is disposed
coaxially with the rotary shaft 12 and the stator 13. As a result
of alternate magnetic function of the permanent magnets 14a and the
stator 13, the rotor 14 is rotatable integrally with the rotary
shaft 12 in a state in which a clearance is secured between the
open end 17 of the yoke 14b and the circuit protection casing
11b.
[0033] In other words, the rotor 14 is disposed so as to be
rotatable integrally with the rotary shaft 12, and rotates around
the stator 13 while keeping a clearance between the circuit
protection casing 11b and the electric circuit substrate 11.
[0034] Further, between the main body part 16a and the inclined
surface part 16c of the yoke 14b, there is provided a ventilation
control plate (ventilation control member) 30 which projects toward
the disk part 21 (to be described hereinafter) of the centrifugal
fan 20.
[0035] The ventilation control plate 30 is integrally fixed to the
outer peripheral surface of the main body part 16a and has an
annular shape to enclose the yoke 14b. The front end part 31 of the
ventilation control plate 30 is proximate to the inner periphery of
the disk part 21. The space or clearance between the rotor 14 and
the disk part 21 is closed by the ventilation control plate 30.
[0036] According to this arrangement, the air that flows from the
side of the electric circuit substrate 11 into the clearance
between the rotor 14 and the disk part 21 is blocked by the
ventilation control plate 30.
[0037] The rotor 14 is made of a magnetic metallic material, and
the ventilation control plate 30 is formed of a synthetic material.
The ventilation control plate 30 is fixed by means of an adhesive
and the like.
[0038] Centrifugal fan 20 is made up of the circular disk part 21
which covers or encloses the brushless motor 10 and is fixed to the
rotary shaft 12; and a multiplicity of vane parts 22, 22, . . .
which are vertically disposed in the axial direction from the
left-open circular edge part 21a of the disk part 21.
[0039] The disk part 21 is of a cup shape as a whole and opens
toward the circuit protection casing 11b, and is disposed so as to
cover or enclose the yoke 14b of the rotor 14, with the dosed edge
part 16b being positioned to cover the innermost portion of the
yoke 14b. Further, the disk part 21 is so arranged that the central
part 21b is fixed to the rotary shaft 12 in a state in which a
clearance is secured between the circular edge part 21a and the
circuit protection casing 11b. The central part 21b is fixed at the
side nearer to the front end 12c of the rotary shaft 12 than at the
central part 16b' of the closed end 16b of the yoke 14b.
[0040] In addition, the disk part 21 has formed therein a plurality
of ventilation openings 23.
[0041] The ventilation openings 23 are to allow the air that has
leaked through the exhaust openings 18, formed in the yoke 14b, to
flow therethrough. Each of the ventilation openings 23 is disposed
along the circumference of the disk part 21 in a manner to enclose
the rotor 14. In addition, the ventilation openings 23 are each
formed at a position which is on the side of the central part 21b
relative to (or as compared with) the front end 31 of the
ventilation control plate 30, the front end 31 of which is
proximate to the disk part 21. The ventilation openings 23 are also
positioned near the front end 31 of the ventilation control plate
30.
[0042] The disk part 21 shown in FIG. 1 is provided with a
plurality of first reinforcing ribs 24a, 24a, . . . which project
inward at a position between the central part 21b inclusive of its
neighborhood and the closing end 16b of the yoke 14b. These first
reinforcing ribs 24a, 24a, . . . serve to increase the strength of
mounting the disk part 21 to the rotary shaft 12.
[0043] Further, at a position between the circular edge 21a of the
disk part 21 and the ventilation openings 23, there are provided a
plurality of second reinforcing ribs 24b, 24b, . . . These second
reinforcing ribs 24b, 24b, . . . serve to increase the strength of
the circular edge 21a of the disk part 21.
[0044] The vanes 22 are disposed such that one end of each is held
by the circular edge 21a of the disk part 21 and that each vane is
at a distance to each other in the circumferential direction in
parallel with the rotary shaft 12.
[0045] Description will now be made about the function/operation of
the motor-operated fan apparatus F according to the invention.
[0046] In this motor-operated fan apparatus F, depending on the
position of the permanent magnet 14a of the rotor 14 as detected by
the sensor magnet 15 fixed to the rotary shaft 12, the coils 13b of
the stator 13 are alternately charged with electric power from the
electric circuit board 11. As a result, a rotating magnetic field
is generated in the permanent magnets 14a of the rotor 14, whereby
the yoke 14b and the rotary shaft 12 and the centrifugal fan 20
rotate integrally.
[0047] At this time, as a result of rotation of the centrifugal fan
20, the space S1 between the open end 17 of the yoke 14b as well as
the circular edge 21a of the disk part 21, and the circuit
protection casing 11b (hereinafter referred to as suction space)
becomes high in pressure. The space S2 between the disk part 21 and
a plurality of vanes 22 (hereinafter referred to as a discharge
space) becomes negative in pressure.
[0048] Therefore, a flow of air is generated from the high pressure
suction space S1 to the negative pressure discharge space S2.
[0049] At this time, the air will flow from the open end 17 of the
main body part 16a, the open end 17 being open toward the circuit
protection casing 11b, to the main body part 16a of the yoke 14b.
The air will, then, move from the plurality of exhaust openings 18
formed in the closing end part 16b and the inclined surface part
16c toward the plurality of ventilation openings 23 formed in the
disk part 21.
[0050] The yoke 14b of the rotor 14 is provided with a ventilation
control plate 30 which projects toward the disk part 21. The
ventilation control plate 30 serves the purpose of closing the
space between the rotor 14 and the disk part 21. The air which
flows into this space will therefore be blocked (or prevented from
flowing through).
[0051] According to this arrangement, even in case the space or
clearance between the rotor 14 and the disk part 21 is relatively
large, the air from the suction space S1 hardly flows into the
above-described space or clearance. Instead, the air is likely to
flow inward so that it becomes possible for the air to flow toward
the stator 13 covered by the rotor 14. In this manner, the stator
13 can be sufficiently cooled.
[0052] In the above-described embodiment, the ventilation control
plate 30 is integrally fixed to the outer periphery of the main
body part 16a of the rotor 14.
[0053] According to this arrangement, the ventilation control plate
30 can be rotated stably together with the rotor 14 without giving
rise to clattering, whereby the air flow can be controlled in a
stable state.
[0054] Furthermore, in the above-described embodiment, the
ventilation control plate 30 projects from a point between the main
body part 16a and the inclined surface 16c of the yoke 14b. The
front end part 31 is positioned near the ventilation openings 23
formed in the disk part 21.
[0055] The exhaust openings 18 are formed in the inclined surface
part 16c, and the ventilation openings 23 are formed at a position
nearer to the central part 21b relative to (or as compared with)
the front part 31 of the ventilation control plate 30.
[0056] In other words, the ventilation control plate 30 is disposed
so as to bridge (or to be present between) those portions of the
exhaust openings 18 which lie on the side of the electric circuit
board 11 and those portions of the ventilation openings 23 which
lie on the side of the electric circuit board 11.
[0057] In this manner, it is possible to let the air coming out of
the exhaust openings 18 to be directed smoothly toward the
ventilation openings 23. As a result, the flow of air becomes
smooth and the cooling of the stator 13 can be more efficiently
performed.
[0058] Although a preferred embodiment of the invention has been
disclosed in detail for illustrative purposes, it will be
recognized that variations or modifications of the disclosed
apparatus, including the rearrangement of the constituent elements,
lie within the scope of this invention.
[0059] For example, in the above-described embodiment, the
ventilation control plate 30 is integrally fixed to the yoke 14b.
The arrangement is not limited to the above.
[0060] In the example of centrifugal fan 40 shown in FIG. 2, a
ventilation control wall 44 as the ventilation control member is
formed in an edge part 43a on the side of the electric circuit
substrate 11.
[0061] This ventilation control wall 44 is elongated from the disk
part 41 toward the rotor 14, with the front end thereof being in
proximity to the exhaust opening 18 which is formed in the inclined
surface 16c of the yoke 14b.
[0062] Also in this case, the ventilation control wall 44 can block
the air to flow from the suction space S1 into the clearance
between the rotor 14 and the disk part 41. Therefore, sufficient
air can flow into the inside of the rotor 14, thereby cooling the
stator 13
[0063] Furthermore, by extending the ventilation control wall 44
from the edge 43a of the ventilation opening 43 of the disk part
41, the ventilation control wall 44 can be formed integrally by
extrusion and the like of a resin. Productivity can thus be
improved.
[0064] In the above-described embodiments, the motor-operated fan
apparatus F is shown to be used for cooling in a radiator and the
like for a motor vehicle. The motor-operated fan apparatus of this
invention is, however, not limited to the use for a motor vehicle,
but may be used for other vehicles such as electric trains, as well
as for other industrial vehicles and the like.
* * * * *