U.S. patent application number 14/085025 was filed with the patent office on 2015-02-26 for inner-rotor fan.
This patent application is currently assigned to DELTA ELECTRONICS, INC.. The applicant listed for this patent is DELTA ELECTRONICS, INC.. Invention is credited to Ming-Yuan HUNG, Chin-Wei LIN, Chin-Sheng LIU.
Application Number | 20150056088 14/085025 |
Document ID | / |
Family ID | 52480544 |
Filed Date | 2015-02-26 |
United States Patent
Application |
20150056088 |
Kind Code |
A1 |
HUNG; Ming-Yuan ; et
al. |
February 26, 2015 |
INNER-ROTOR FAN
Abstract
An inner-rotor fan includes a hub, a retaining tube, and a
magnetic ring. The retaining tube is disposed in the hub, and the
magnetic ring is disposed on the retaining tube. The retaining tube
and the hub are formed as a single piece, and thus the stability of
the fan is increased. Moreover, the magnetic flux in an inner hole
of the magnetic ring is about 0 Wb, and thus an iron ring within
the magnetic ring may be excluded.
Inventors: |
HUNG; Ming-Yuan; (Kuei San,
TW) ; LIN; Chin-Wei; (Kuei San, TW) ; LIU;
Chin-Sheng; (Kuei San, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DELTA ELECTRONICS, INC. |
Kuei San |
|
TW |
|
|
Assignee: |
DELTA ELECTRONICS, INC.
Kuei San
TW
|
Family ID: |
52480544 |
Appl. No.: |
14/085025 |
Filed: |
November 20, 2013 |
Current U.S.
Class: |
417/423.7 |
Current CPC
Class: |
F04D 25/0606
20130101 |
Class at
Publication: |
417/423.7 |
International
Class: |
F04D 25/02 20060101
F04D025/02; F04D 29/40 20060101 F04D029/40 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 21, 2013 |
CN |
201310368404.1 |
Claims
1. An inner-rotor fan, comprising: a fan frame; a bearing disposed
on the fan frame; and a rotor comprising: a hub; a retaining tube
disposed in the hub; a magnetic ring, having an inner hole, wherein
the retaining tube is disposed in the inner hole; a shaft, disposed
on the hub, located within the retaining tube, and passing through
the bearing; and a plurality of blades disposed around the hub,
wherein the retaining tube and the hub are formed as a single
piece, and a magnetic flux in the inner hole is about 0 Wb.
2. The inner-rotor fan as claimed in claim 1, wherein the magnetic
ring is a plastic magnetic ring, and made of magnetic powder and
plastic.
3. The inner-rotor fan as claimed in claim 2, wherein the hub and
the retaining tube have the same material, and the hub and the
retaining tube is made of plastic.
4. The inner-rotor fan as claimed in claim 1, wherein the magnetic
ring has a groove adjacent to the retaining tube.
5. The inner-rotor fan as claimed in claim 1, excluding a magnetic
field shielding element located between the magnetic ring and the
shaft.
6. The inner-rotor fan as claimed in claim 1, wherein the retaining
tube has a plurality of first positioning structures, and the
magnetic ring has a plurality of second positioning structures
disposed on the inner hole, wherein the first positioning structure
is retained on the second positioning structure to make the
magnetic ring rotate following the retaining tube.
7. The inner-rotor fan as claimed in claim 6, wherein the first
positioning structure is a rib, the second positioning structure is
a groove, and the rib is located in the groove.
8. The inner-rotor fan as claimed in claim 6, wherein the first
positioning structure is a groove, the second positioning structure
is a rib, and the rib is located in the groove.
9. The inner-rotor fan as claimed in claim 1, wherein the fan frame
comprises a base and a sleeve disposed on the base, and the bearing
is disposed in the sleeve.
10. The inner-rotor fan as claimed in claim 9, wherein the fan
frame further comprises a holding portion disposed on the base and
around the sleeve.
11. The inner-rotor fan as claimed in claim 10, further comprising
a stator disposed on the holding portion, and corresponding to the
magnetic ring.
12. The inner-rotor fan as claimed in claim 11, wherein the sleeve
further comprises a support portion, the stator further comprises
an electric power board fixed on the support portion and a coil
electrically connected with the electric power board and
corresponding to the magnetic ring.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application claims priority of China Patent Application
No. 201310368404.1, filed on Aug. 21, 2013, the entirety of which
is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present disclosure relates to a fan, and in particular,
to an inner-rotor fan.
[0004] 2. Description of the Related Art
[0005] In general, a rotor of a conventional inner-rotor fan has a
hub, a shaft, and a magnetic ring around the shaft. The rotor is
rotated by the magnetic field relative to the stator and the
magnetic ring.
[0006] FIG. 1 is a transverse cross-sectional view of a
conventional magnetic ring 1. As shown in FIG. 1, the magnetic ring
1 includes a plurality of south poles S and north poles N
alternately arranged. Each of the south poles S and the north poles
N are exposed from the inner wall 11 and the outer wall 12 of the
magnetic ring 1. Therefore, the magnetic field generated by the
magnetic ring 1 is distributed in an inner hole 13 of the magnetic
ring 1, and the rotational stability of the fan is decreased.
[0007] To solve the described problem, an iron ring is installed in
the hub of the fan. The iron ring passes through the inner hole 13
and fixed on the inner wall 11 of the magnetic ring 1. However, the
iron ring is made of metal, and thus the manufacturing cost of the
inner-rotor fan is increased. Furthermore, the iron ring and the
hub are not formed as a single piece, and thus the rotational
stability of the fan is decreased
BRIEF SUMMARY OF THE INVENTION
[0008] To solve the described problems, an object of the present
disclosure is to decrease the manufacturing cost of the inner-rotor
fans, and to increase to rotational stability of the inner-rotor
fans.
[0009] The present disclosure provides an inner-rotor fan including
a fan frame, a bearing, and a rotor. The bearing is disposed on the
fan frame. The rotor includes a hub, a retaining tube, a magnetic
ring, a shaft and a plurality of blades. The retaining tube is
disposed in the hub. The magnetic ring has an inner hole, and the
retaining tube is disposed in the inner hole. The shaft is disposed
on the hub, located in the retaining tube, and passes through the
bearing. The blades are respectively disposed around the hub. The
retaining tube and the hub are formed as a single piece, and the
magnetic flux in the inner hole is about 0 Wb.
[0010] In conclusion, the inner-rotor fan of the present disclosure
has a magnetic ring with about 0 Wb of magnetic flux in the inner
hole thereof, and therefore, the iron ring is excluded to decrease
the manufacturing cost of the inner-rotor fan. Moreover, since the
retaining tube and the hub are formed as a single piece, the
rotational stability of the inner-rotor fan is increased.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention can be more fully understood by reading the
subsequent detailed description and examples with references made
to the accompanying drawings, wherein:
[0012] FIG. 1 is a transverse cross-sectional view of a
conventional magnetic ring.
[0013] FIG. 2 is a perspective view of an inner-rotor fan according
to the present disclosure.
[0014] FIG. 3 is a cross-sectional view of the inner-rotor fan
according to the present disclosure.
[0015] FIG. 4 is an exploded view of a rotor according to the
present disclosure.
[0016] FIG. 5 is a transverse cross-sectional view of the magnetic
ring according to the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0017] FIG. 2 is a perspective view of an inner-rotor fan 2
according to the present disclosure. FIG. 3 is a cross-sectional
view of the inner-rotor fan 2 according to the present disclosure.
FIG. 4 is an exploded view of a rotor 50 according to the present
disclosure. As shown in FIGS. 2, 3 and 4, the inner-rotor fan 2
includes a fan frame 20, a stator 30, a bearing 40, and a rotor 50.
The fan frame 20 includes a base 21, a sleeve 22, a holding portion
23, and a plurality of support ribs 24 connected to the base 21.
The sleeve 22 and the holding portion 23 are a tube structure
disposed on the base 21 and extended along an extension direction
D1. In some embodiments, the extension direction D1 is
perpendicular to the base 21. The base 21, the sleeve 22, and the
holding portion 23 are formed as a single piece, or are independent
parts according to a variety of designs. Moreover, the sleeve 22 is
located in the retaining tube 53.
[0018] The stator 30 is fixed on the holding portion 23. The stator
30 includes a metal element 31, a holding rack 32, a coil 33, and
an electric power board 34. The metal element 31 is disposed on the
holding rack 32. In some embodiments, the metal element 31 is made
of silicon steel sheets. The metal element 31 is covered by an
insulation layer and is insulated relative to the coil 33. In some
embodiments, the metal element 31 is made of magnetic material.
[0019] The coil 33 is wound to the holding rack 32 and the metal
element 31, and corresponds to the magnetic ring 54. The electric
power board 34 is fixed on the inner wall of the holding portion 23
and a support portion 221 of the sleeve 22. Further, the electric
power board 34 is electrically connected to the coil 33. The
holding rack 32 is fixed on the electric power board 34. The
bearing 40 is fixed in the sleeve 22, and extended along an axis
AX1. In some embodiments, the extension direction D1 is parallel to
axis AX1.
[0020] The rotor 50 includes a hub 51, a shaft 52, a retaining tube
53, a magnetic ring 54, and a plurality of blades 55. The hub 51 is
a hollow structure, and the center of the hub 51 is located at the
axis AX1. The stator 30 and the bearing 40 are located in the hub
51.
[0021] The shaft 52 is disposed in the hub 51, extended along the
axis AX1, and passes through the bearing 40. The retaining tube 53
is a tube structure disposed on an inner surface 511 of the hub 51
and extended along the extension direction D1. The retaining tube
53 is around the shaft 52, the sleeve 22, and the bearing 40. A
plurality of first positioning structures 532 is disposed on an
outer surface 531 of the retaining tube 53.
[0022] The magnetic ring 54 is a tube structure extended along the
extension direction D1. The magnetic ring 54 is disposed on the
retaining tube 53 and corresponds to the stator 30. The magnetic
ring 54 has an inner wall 541, an inner hole 542, a plurality of
second positioning structures 543, and an outer wall 544 facing the
stator 30. The inner wall 541 forms an inner hole 542 extended
along the axis AX1, and the retaining tube 53 is disposed on the
inner hole 542. The second positioning structure 543 is disposed on
the inner wall 541. The first positioning structure 532 is retained
on the second positioning structure 543 to make the magnetic ring
54 rotate following the retaining tube 53.
[0023] In the embodiment, the first positioning structure 532 is a
rib extended along the extension direction D1, and the second
positioning structure 543 is a groove extended along the extension
direction D1. Further, the rib is located in the groove. In another
embodiment, the first positioning structure 532 is a groove, and
the second positioning structure 543 is a rib. Furthermore, in a
situation where the magnetic field corresponding to the coil 33 is
not influenced, a groove 5401 may be formed on a magnetic ring 54
adjacent to the retaining tube 53. The weight of the rotor 50 is
decreased by the groove 5401. Furthermore, a balancing material may
be disposed in the groove 5401 to balance the rotation of the rotor
50. Therefore, the vibration of the inner-rotor fan 2 is
decreased.
[0024] The blades 55 are arranged around the hub 51. In the
embodiment, when power is applied to the coil 33, the rotor 50 is
rotated by an alternating magnetic field between the coil 33 and
the magnetic ring 54.
[0025] In the embodiment, the magnetic ring 54 is a plastic
magnetic ring 54 made of magnetic powder and plastic. The magnetic
powder is distributed in the plastic. Before the plastic is
solidified, a magnetic field is applied to the magnetic ring 54 to
change the arrangement of the magnetic powder. After the plastic is
solidified, the arrangement of the magnetic powder is fixed to make
the plastic magnetic ring 54 generate a predetermined magnetic
field.
[0026] FIG. 5 is a transverse cross-sectional view of the magnetic
ring 54 according to the present disclosure. As shown in FIG. 5,
the south poles S and the north poles N of the magnetic ring 54 of
this embodiment are alternately arranged on the magnetic ring 54
and adjacent to the outer wall 544 of the magnetic ring 54.
Therefore, the magnetic field does not (or little) pass through the
inner wall 541 of the magnetic ring 54. Therefore, the magnetic
flux in the inner hole 542 is about 0 Wb.
[0027] Since the magnetic flux in the inner hole 542 of the
magnetic ring 54 is about 0 Wb, the inner-rotor fan 2 of the
embodiment excludes a magnetic field shielding element (such as an
iron ring) disposed on an inner wall 541 of the magnetic ring 54
(or between the magnetic ring 54 and the shaft 52). Therefore, the
manufacturing cost of the inner-rotor fan 2 is decreased.
[0028] Further, since the embodiment excludes the magnetic field
shielding element made of metal, the retaining tube 53 may be made
of cheaper plastic, and thus the manufacturing cost of the
inner-rotor fan 2 is decreased. In addition, the hub 51 and the
retaining tube 53 have the same material, and the hub 51 and the
retaining tube 53 are made of plastic. Therefore, the retaining
tube 53 and the hub 51 are easily formed as a single piece, and the
rotational stability of the rotor 50 is increased.
[0029] Moreover, since the retaining tube 53 is made of plastic,
the positioning structure is easily formed on the retaining tube 53
to limit the rotation between the magnetic ring 54 and the
retaining tube 53, increasing the rotational stability of the rotor
50.
[0030] In conclusion, the inner-rotor fan of the present disclosure
has a magnetic ring with about 0 Wb of magnetic flux in the inner
hole thereof, and therefore, the iron ring is excluded to decrease
the manufacturing cost of the inner-rotor fan. Moreover, since the
retaining tube and the hub are formed as a single piece, the
rotational stability of the inner-rotor fan is increased.
[0031] While the invention has been described by way of example and
in terms of preferred embodiment, it is to be understood that the
invention is not limited thereto. 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.
* * * * *