U.S. patent application number 10/500541 was filed with the patent office on 2005-05-19 for miniature fan or micro-fan.
Invention is credited to Winkler, Wolfgang Arno.
Application Number | 20050106046 10/500541 |
Document ID | / |
Family ID | 7967071 |
Filed Date | 2005-05-19 |
United States Patent
Application |
20050106046 |
Kind Code |
A1 |
Winkler, Wolfgang Arno |
May 19, 2005 |
Miniature fan or micro-fan
Abstract
A miniature fan or micro-fan (200) features a fan housing (150)
through which a substantially annular air duct extends in the axial
direction, there being arranged in a central region of the air duct
an electronically commutated external-rotor motor (202) whose
external rotor, equipped with at least one permanent magnet (86),
carries an impeller wheel (204) that is arranged rotatably in the
air duct. A circuit board configuration (168) has a motor region
that is arranged in the central region of the air duct and carries
at least one galvanomagnetic rotor position sensor that is
controllable by the magnetic field of the permanent magnet (86)
provided on the external rotor. The board has a component region
for the reception of electronic components (170) of the
external-rotor motor, which component region is arranged
substantially outside the air duct, and which comprises a bridge
portion, via which the motor region of the circuit board
configuration is electrically connected to the component region
(168).
Inventors: |
Winkler, Wolfgang Arno; (St
Georgen, DE) |
Correspondence
Address: |
WARE FRESSOLA VAN DER SLUYS &
ADOLPHSON, LLP
BRADFORD GREEN BUILDING 5
755 MAIN STREET, P O BOX 224
MONROE
CT
06468
US
|
Family ID: |
7967071 |
Appl. No.: |
10/500541 |
Filed: |
July 1, 2004 |
PCT Filed: |
December 6, 2002 |
PCT NO: |
PCT/EP02/13822 |
Current U.S.
Class: |
417/423.3 ;
417/423.14; 417/423.7 |
Current CPC
Class: |
H02K 29/08 20130101;
H02K 11/33 20160101; F04D 25/0633 20130101; F04D 25/0646 20130101;
H02K 7/14 20130101; H02K 11/215 20160101 |
Class at
Publication: |
417/423.3 ;
417/423.7; 417/423.14 |
International
Class: |
F04B 017/00; F04B
035/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 11, 2002 |
DE |
202 01 272.7 |
Claims
1. A miniature fan or micro-fan which comprises a fan housing (22;
68; 112; 150) through which a substantially annular air duct (114;
152) extends in the axial direction, there being arranged in a
central region of the air duct (114; 152) a carrier hub (64; 118;
156) which carries the internal stator (72; 122) of an
electronically commutated external-rotor motor (28, 30; 70; 158;
202) whose external rotor (80; 160), equipped with at least one
permanent magnet (86), carries an impeller wheel (130; 162) that is
arranged rotatably in the air duct (114), and comprising a circuit
board configuration (32; 90, 94; 134; 163) which comprises a motor
region (34; 42) that is arranged in the central region of the air
duct between the carrier hub (64; 118) and the internal stator
(122), and carries at least one galvanomagnetic rotor position
sensor (36; 44) that is controllable by the magnetic field of the
permanent magnet (86) provided on the external rotor, which
comprises a component region (50; 138) for the reception of
electronic components (96; 170) of the external-rotor motor, which
component region is arranged substantially outside the air duct
(114; 152); and which comprises a bridge portion (40; 48; 136; 174)
by way of which the motor region (163) of the circuit board
configuration is electrically connected to the component region
(168).
2. The fan according to claim 1, wherein the motor region, bridge
portion, and component region are implemented as parts of the same
circuit board.
3. The fan according to claim 1 or 2, wherein the circuit board is
implemented at least locally in flexible fashion.
4. The fan according to claim 3, wherein the flexible region is
deflected between the motor region and component region.
5. The fan according to any of the preceding claims, wherein the
circuit board configuration comprises flexible stranded conductors
in the bridge region between the motor region and component
region.
6. The fan according to any of the preceding claims, which is
implemented as an axial fan.
7. The fan according to any of the preceding claims, wherein the
internal stator is implemented with claw poles (74; 124) and an
annular winding (76; 126; 164).
8. The fan according to claim 7, wherein the annular winding (76;
126; 164) is electrically connected to the motor region of the
circuit board configuration.
9. The fan according to any of the preceding claims, wherein the
component region (138; 168) is arranged substantially in a
closed-off region (98; 142; 172) of the fan housing (22; 68).
10. The fan according to claim 9, wherein the closed-off region is
sealed, preferably in liquid-tight fashion, by means of a cover
(100; 172).
11. The fan according to claim 10, wherein the component region
(94) of the circuit board configuration is mounted on the cover
(100) by means of at least one support member (102).
12. The fan according to any of the preceding claims, which is
controllable via a data bus.
13. The fan according to any of the preceding claims, wherein a
bridge portion (40, 48; 136) of the circuit board configuration
(32; 90, 94; 134; 163) extends in the region of a strut, the latter
connecting the external-rotor motor (28, 30) to the fan housing
(22).
14. A miniature fan or micro-fan which comprises a fan housing (22;
68; 112; 150) through which a substantially annular air duct (114;
152) extends in the axial direction, that housing being connected
via at least one carrier member to a carrier hub (64; 118; 156)
that is arranged in a central region of the air duct (114; 152) and
carries the internal stator (72; 122), comprising an annular
winding (76; 126; 164) and implemented as a claw-pole stator, of an
electronically commutated external-rotor motor (28, 30; 70; 158)
whose external rotor (80; 160), equipped with at least one
permanent magnet (86), carries fan blades (130; 162) that are
arranged in the air duct (114), and comprising a circuit board
configuration (32; 90, 94; 134; 163) which comprises a motor region
(34; 42) that is arranged on the radially inner side of the air
duct between the carrier hub (64; 118) and the claw-pole stator
(122), is adapted for electrical connection to the annular winding
(76; 126; 164) of the claw-pole stator, and carries at least one
galvanomagnetic rotor position sensor (36; 44) that is controllable
by the magnetic field of the at least one permanent magnet (86)
provided on the external rotor, which comprises a component region
(50; 138) for the reception of electronic components (96) of the
external-rotor motor, which component region is arranged
substantially outside the air duct; and which comprises a bridge
portion (40; 48; 136; 174) by way of which the motor region (163)
of the circuit board configuration is electrically connected to the
component region (168).
15. The fan according to claim 14, which is implemented as an axial
fan.
16. The fan according to claim 14 or 15, wherein the component
region (138; 168) is arranged substantially in a closed-off region
(98; 142; 172) of the fan housing (22; 68).
17. The fan according to claim 16, wherein the closed-off region is
sealed, preferably in liquid-tight fashion, by a cover (100;
172).
18. The fan according to claim 17, wherein the component region
(94) of the circuit board configuration is mounted on the cover
(100) by means of at least one support member (102).
19. The fan according to any of claims 14 through 18, which is
controllable via a data bus.
Description
[0001] This application is a section 371 of PCT/EP02/13822, filed 6
DEC. 2002 and published 17 Jul. 2003 as WO 03-058 796-A1.
FIELD OF THE INVENTION
[0002] The invention relates to a miniature fan or micro-fan that
is driven by an electronically commutated external-rotor motor.
BACKGROUND
[0003] Miniature fans or micro-fans serve, for example, to cool
processors in computer, to cool small devices, etc., and they have
very small dimensions. For example:
[0004] fans of PAPST series 250 have dimensions of
8.times.25.times.25 mm,
[0005] those of PAPST series 400F, dimensions of
10.times.40.times.40 mm,
[0006] those of PAPST series 400, 20.times.40.times.40 mm,
[0007] those of PAPST series 500, 50.times.50.times.15 mm, and
[0008] those of PAPST series 600, 60.times.60.times.25 mm.
[0009] The power consumption of such fans is 0.4-0.6 W for series
250, 0.7-0.9 W for series 400F, 0.9-1.6 W for series 400, and
0.8-3.4 W for series 600. This defines the preferred field of
application of the present invention.
[0010] In fans that are driven by an electronically commutated
external-rotor motor, the motor is large in relation to the overall
size of the fan, which is disadvantageous in terms of the flow rate
(V/t) and pressure increase .DELTA.p of the fan.
SUMMARY OF THE INVENTION
[0011] It is therefore an object of the invention to make available
a new miniature fan or micro-fan.
[0012] According to the invention, this object is achieved by
arranging a rotor position sensor centrally but other control
components outside the air duct. It is thereby possible to mount
the at least one rotor position sensor in space-saving fashion on
the motor region of the circuit board configuration, and to arrange
other components in a component region outside the air duct, thus
allowing the annular air flow cross section to be made larger than
previously. This permits larger fan blades to be used, and thus a
greater flow rate and/or a greater pressure increase to be achieved
for the same physical size.
[0013] Another manner of achieving the stated object is to arrange
a motor region, of the control circuit board, on an inner side of
the air duct between the carrier hub and the claw-pole stator. The
combination according to this claim results, even in micro-fans, in
very favorable values for flow rate and pressure increase, which
are increasingly in demand nowadays. A compact design with a large
annular air flow cross section, and consequently a particularly
large flow rate, is thus obtained, so that a configuration of this
kind according to the invention represents a particularly
advantageous combination for miniature fans and micro-fans.
[0014] These approaches to achieving the object of the present
invention create the possibility of increasing the number of
functions for a miniature fan or micro-fan. For example, when
miniature fans or micro-fans are used in open- or closed-loop
control systems or management systems, they must not generate any
electromagnetic interference, i.e. their electromagnetic
compatibility (EMC) must meet high standards; this requires more
components and more-complex circuits, which the invention now makes
possible for the first time in compact form for miniature fans and
micro-fans as well.
[0015] With the invention, it is also possible to integrate into
the circuitry of such a fan additional functions that are now
increasingly in demand, e.g. PWM open- and closed-loop control
systems, analog rotation speed controllers, digital rotation speed
controllers, programmable rotation speed controllers, switching
thresholds for analog control systems, etc. This also allows
reliable control of a miniature fan or micro-fan via a data bus
such as those now common, for example, in motor vehicles. Further
details and advantageous refinements of the invention are evident
from the exemplary embodiments, in no way to be understood as a
limitation of the invention, that are described below and
illustrated in the drawings.
BRIEF FIGURE DESCRIPTION
[0016] FIG. 1 is a plan view of a double fan comprising two
miniature fans or micro-fans, at very greatly enlarged scale;
[0017] FIG. 2 is an individual depiction of a circuit board used in
the double fan of FIG. 1;
[0018] FIG. 3 shows a first embodiment of an individual miniature
fan or micro-fan in which most of the electronic components are
housed in a lateral housing part, the connection from the motor to
the lateral components being accomplished via a flexible
conductor;
[0019] FIG. 4 shows a second embodiment of a miniature fan, viewed
in the direction of arrow IV of FIG. 5, in which most of the
electronic components are housed in a lateral housing part, the
connection from the motor to the lateral components being
accomplished via a rigid conductor;
[0020] FIG. 5 is a section viewed along line V-V of FIG. 4;
[0021] FIG. 6 shows a third embodiment of a miniature fan, viewed
in the direction of arrow VI of FIG. 7, in which most of the
electronic components are housed in a narrow lateral housing part
and the connection from the motor to the lateral components is
accomplished via flexible stranded conductors;
[0022] FIG. 7 is a section viewed along line VII-VII of FIG. 6;
and
[0023] FIG. 8 depicts a micro-fan according to the present
invention at approximately actual size.
DETAILED DESCRIPTION
[0024] FIG. 1 shows, at greatly enlarged scale, a double fan 20
comprising a housing 22 in which two miniature fans or micro-fans
24, 26, each driven by an electronically commutated external-rotor
motor 28, 30, are arranged next to one another. These motors 28, 30
are rigidly connected to housing 22 by way of struts (not
depicted).
[0025] According to the invention and as shown in FIG. 2, a circuit
board 32 that has, for motor 28, a first approximately annular part
34, on which a Hall IC 36 and four attachment points 38 for the
winding ends of motor 28 are provided, is used in the double fan of
FIG. 1. Part 34 is connected, via a first bridge 40 comprising
printed conductors (not depicted), to a second approximately
annular part 42 on which are located a Hall IC 44 and four
attachment points 46 for the winding ends (not depicted) of motor
30.
[0026] Part 42 is connected, via a second bridge 48 comprising
printed conductors (not depicted), to an (in this case,
rectangular) part 50 on which most of the electronic components of
the two motors 28, 30 are arranged. The connection to motors 28, 30
is accomplished via printed conductors (not depicted) on parts 34,
40, 42, 48, and 50.
[0027] Bridges 40, 48 are preferably arranged in such a way that
they each extend under a strut that respectively connects motor 28,
30 to housing 22. For that purpose they can also, as applicable,
extend obliquely.
[0028] FIG. 3 depicts an analogous arrangement 60 comprising a
single miniature fan 62, implemented as an axial fan, that is shown
greatly enlarged. This fan has a hub 64 that is connected via
struts 66 to a housing 68. Mounted on this hub 64 is an
external-rotor motor 70 that has an internal stator 72 having claw
poles 74 and an annular winding 76. Rotating around internal stator
72 is an external rotor 80 having a rotor cup 82 made of plastic,
into which is injection-embedded a magnetic yoke ring 84 on which
is arranged an annular permanent magnet 86 that is radially
magnetized. The blades of fan 62 are labeled 106, and are mounted
on rotor cup 82. Located between internal stator 72 and hub 64 is a
circuit board 90, connected to which electrically and mechanically
is a flexible conductor 92 that leads to a circuit board 94 and is
electrically and mechanically connected thereto. Most of the
electronic components 96 of motor 70 are located on circuit board
94, with the exception of a Hall IC (not depicted) that is arranged
on circuit board 90 in the region of the magnetic field of rotor
86, and is controlled by that magnetic field.
[0029] Circuit board 94 with its components 96 is located in a
lateral housing part 98 that, after assembly, is sealed by a cover
100 on which circuit board 94 is secured by means of support
members 102.
[0030] It is advantageous here that with this arrangement, cover
100 can be swung down to the right for assembly; and that after
assembly, it can be connected in liquid-tight fashion to part 98.
Flexible conductor 92 thus enables problem-free assembly.
[0031] FIGS. 4 and 5 show a miniature fan 110 comprising an
approximately rectangular housing 112 that has an air duct 114 in
which hub 118 of an external-rotor motor 120 is held by struts 116.
As in FIG. 3, motor 120 has an internal stator 122 with claw poles
124 and an annular winding 126. An external rotor 128, on which
five fan blades 130 of an axial fan are provided, rotates about
internal stator 122.
[0032] A rigid circuit board 134, whose shape is indicated with
dashed lines in FIG. 4, extends between hub 118 and internal stator
122. Circuit board 134 is approximately annular in the region
between hub 118 and internal stator 122, and it carries there a
Hall IC (not depicted) as well as connecting points for the
attachment of annular winding 126. The reader is referred to the
analogous depiction in FIG. 2.
[0033] From the annular portion of circuit board 134, a narrow
bridge 136 goes to a larger, approximately rectangular part 138 on
which the essential electronic components 140 of motor 120 are
arranged (see FIG. 5). This part 138 is located in a space 144 that
can be sealed by a cover 142.
[0034] As is directly apparent, circuit board 134 populated with
components 140 can be very easily installed before cover 142 is put
in place.
[0035] Housing 112 is equipped with four openings 148 for mounting
it.
[0036] FIGS. 6 and 7 show, once again greatly enlarged, a miniature
fan or micro-fan comprising a housing 150 in which is provided an
air duct 152 in which hub 156 of a claw-pole external-rotor motor
158, whose external rotor 160 carries five blades 162, is mounted
by means of struts 154.
[0037] Located between hub 156 and motor 158 is an annular circuit
board 163 that, similarly to FIG. 2, carries a Hall IC (not
depicted) and attachment points for stator winding 164 of motor
158.
[0038] Also provided, to the side of air duct 152, is a housing
part 166 in which a circuit board 168 having electronic components
170 of motor 158 is mounted. Housing part 166 is closed after
assembly by a cover 172.
[0039] The connection from circuit board 163 to circuit board 168
is accomplished here by means of flexible electrical conductors
174, called stranded conductors, that are permanently soldered onto
the two circuit boards 163 and 168. Stranded conductors of this
kind can be mounted particularly easily on a strut 154 of fan
housing 150.
[0040] FIG. 8 shows a micro-fan 200 according to the invention. A
one-centimeter length is indicated at the left as a scale; in other
words, fan 200 is shown slightly enlarged. It has external
dimensions of 35.times.40.times.8 mm, and a weight of approx. 5 g.
Five fan blades 204 are arranged externally on its motor 202. The
motor has a power consumption of 0.5 W and a rated rotation speed
of 9000 rpm. Viewed as depicted in FIG. 8, fan 200 runs
counterclockwise and blows toward the back.
[0041] Housing 150 of fan 200 has, on the right side as depicted,
an enlargement in which circuit board 168 with (schematically
indicated) electronic components 170 is located (see FIG. 7). The
lateral enlargement is closed by cover 172, but in some cases can
also be open. The connection from circuit board 168 to motor 202 is
preferably accomplished in the manner depicted, in greatly enlarged
fashion, in FIGS. 6 and 7.
[0042] Because components 170 are not arranged directly inside
motor 202 but instead in the lateral enlargement of housing 150,
the diameter of motor 202 can be correspondingly reduced, e.g. from
17.5 to 13.5 mm. With only slightly greater dimensions for housing
150, the flow rate V/t of fan 200 for a given static pressure
.DELTA.pf thus rises approximately 80 to 110%, e.g. from 1.5
m.sup.3/h to 3.2 m.sup.3/h. The invention thus allows an improved
flow rate, and consequently better cooling performance, to be
obtained in such micro-fans with very simple means.
[0043] Aspects common to all the approaches depicted are that they
greatly simplify, even for very small fans, assembly of the
electronics for the fan's electronically commutated drive motor;
that the volume and weight of the fan are not substantially
increased; and that they enable new fan electronics functions for
miniature fans and micro-fans of this kind.
[0044] Lateral installation of the motor electronics further allows
the size of the motor hub to be reduced, i.e. the cross section for
air passage, and therefore the fan performance and pressure
increase of the fan, can be very easily increased by means of the
invention.
[0045] Many variants and modifications are of course possible
within the scope of the present invention.
* * * * *