U.S. patent application number 16/191683 was filed with the patent office on 2020-02-06 for fan system and sound suppression method thereof.
The applicant listed for this patent is Winstron Corp.. Invention is credited to Chih-Chun Liu, Hung Jen Su, Cheng-Pang Wang, Wen-Chen Wu.
Application Number | 20200045845 16/191683 |
Document ID | / |
Family ID | 69227629 |
Filed Date | 2020-02-06 |
United States Patent
Application |
20200045845 |
Kind Code |
A1 |
Wang; Cheng-Pang ; et
al. |
February 6, 2020 |
FAN SYSTEM AND SOUND SUPPRESSION METHOD THEREOF
Abstract
A fan system is used for dissipating heat of an electronic
device. The fan system includes a fan, a hollow structure, and a
control circuit. Sound waves made by the fan are transmitted to an
interior of the hollow structure when the fan is operating. The
control circuit is connected to the hollow structure and is
configured to control deformation/deformations of the hollow
structure according to a state/states of the fan and/or the
electronic device, which change a volume of the interior of the
hollow structure for making a resonance frequency of the hollow
structure being approximate to a rotation speed of the fan or being
the same as the rotation speed of the fan.
Inventors: |
Wang; Cheng-Pang; (New
Taipei, TW) ; Liu; Chih-Chun; (New Taipei, TW)
; Su; Hung Jen; (New Taipei, TW) ; Wu;
Wen-Chen; (New Taipei, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Winstron Corp. |
New Taipei |
|
TW |
|
|
Family ID: |
69227629 |
Appl. No.: |
16/191683 |
Filed: |
November 15, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 19/002 20130101;
F04D 29/665 20130101; G06F 1/20 20130101; G06F 1/206 20130101; F04D
29/663 20130101; H05K 7/20172 20130101; H05K 7/20209 20130101; H05K
7/20727 20130101 |
International
Class: |
H05K 7/20 20060101
H05K007/20 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 1, 2018 |
TW |
107126742 |
Claims
1. A fan system for cooling an electronic device, comprising: a
fan; a hollow structure in the shape of a neck container, with a
sound wave transmitted to the hollow structure when the fan is
operating; and at least one control circuit connected to the hollow
structure and configured to control a deformation degree of the
hollow structure based on an operation state of at least one of the
fan and the electronic device.
2. The fan system according to claim 1, wherein the hollow
structure comprises a body and a neck, the body has a first width
in a first direction and the neck has a second width in the first
direction, the second width is smaller than the first width, and
the body is connected to the neck to surround and form an interior
of the hollow structure.
3. The fan system according to claim 1 further comprising a
channel, with the hollow structure comprising an interior, the
channel extended to the fan and communicated with the interior of
the hollow structure, and the sound wave transmitted to the hollow
structure through the channel.
4. The fan system according to claim 1, wherein the material of the
hollow structure is shape memory alloy, and the at least one
control circuit heats the hollow structure to change the thickness
of the hollow structure.
5. The fan system according to claim 2, wherein the material of the
body and the neck is shape memory alloy, and the at least one
control circuit heats at least one of the body and the neck to
change the respective thickness of at least one of the body and the
neck.
6. The fan system according to claim 2, wherein the body comprises
a plurality of shape memory alloy planes connected to each other,
and the at least one control circuit heats the shape memory alloy
planes to change the thickness of the body.
7. The fan system according to claim 2, wherein the neck comprises
a plurality of shape memory alloy planes connected to each other,
and the at least one control circuit heats the shape memory alloy
planes to change the thickness of the neck.
8. A fan system for cooling an electronic device, and the fan
system comprising: a fan; a body surrounding the fan, wherein an
interior face of the body faces the fan and is spaced from the fan,
the interior face comprises a groove, and the fan transmits a sound
wave to the groove; and a control circuit connected to the body,
wherein the control circuit controls the deformation of the body
based on an operation state of at least one of the fan and the
electronic device for changing the volume of the groove.
9. The fan system according to claim 8, wherein the material of the
body is shape memory alloy, and the control circuit heats the body
to change the thickness of the body.
10. The fan system according to claim 8, wherein the groove
comprises a first width in a first direction.
11. The fan system according to claim 8, wherein the groove
comprises a first section and a second section in a first
direction, and the interior face is closer to the first section
than to the second section, the first section comprises a second
width in a second direction and the second section comprises a
third width in the second direction, and the second width is
smaller than the third width.
12. A fan system for cooling an electronic device, and the fan
system comprising: a fan; a body surrounding the fan, wherein the
body comprises an interior face and a side face next to the
interior face, wherein the interior face faces the fan and the
interior face is spaced from the fan, the side face comprises a
groove, and a sound wave is transmitted to the groove when the fan
is operating; and a control circuit connected to the body, wherein
the control circuit controls the deformation of the body based on
the operation state of at least one of the fan and the electronic
device for changing the volume of the groove.
13. The fan system according to claim 12, wherein the material of
the body is a shape memory alloy, and the control circuit heats the
body to change the thickness of the body.
14. The fan system according to claim 12, wherein the groove
comprises a first section and a second section in a first
direction, the side face is closer to the first section than to the
second section, and the first section has a first width in a second
direction and the second section has a second width in the second
direction, and the first width is smaller than the second width.
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). 107126742 filed
in Taiwan, R.O.C. on Aug. 1, 2018, the entire contents of which are
hereby incorporated by reference.
TECHNICAL FIELD
[0002] The disclosure relates to a fan system and sound suppression
method thereof, more particularly to a fan system and a method for
suppressing the noise with different frequency.
BACKGROUND
[0003] Conventionally, the fan is often disposed behind the
hardware device for the rack mount disposition of the server with
high memory capacitance, but the spacing between the fan and the
hardware device is decreased as the requirement in spacing usage
becomes more and more strict. The read performance and write
performance of the hardware device may be effected by the noise
frequency generated by the fan in operation. However, the rotation
speed of the fan is changed based on the inside temperature of the
server, and there will be various noise frequencies due to the
different rotation speeds. As a result, it's difficult to suppress
the noise generated by the fan.
[0004] For these reasons, it presently needs a preferable fan
system to improve the above problems.
SUMMARY
[0005] A fan system is disclosed in an embodiment based on this
disclosure, wherein the fan system is for cooling an electronic
device, and the fan system comprises: a fan and a hollow structure,
wherein the hollow structure in the shape of a neck container, and
a sound wave is transmitted to the hollow structure when the fan is
operating. There is at least one control circuit connected to the
hollow structure, and the at least one control circuit connected to
the hollow structure and configured to control a deformation degree
of the hollow structure based on an operation state of at least one
of the fan and the electronic device. Hence, the volume of the
hollow structure may be changed for making the resonance frequency
of the hollow structure approximate or even equal to a rotation
frequency of the fan.
[0006] A fan system is disclosed in an embodiment based on this
disclosure, wherein the fan system is for cooling an electronic
device, and the fan system comprises: a fan; a body surrounding the
fan, wherein an interior face of the body faces the fan and the
interior face is spaced from the fan. In addition, the interior
face comprises a groove, and the fan transmits a sound wave to the
groove. Also, there is a control circuit connected to the body, and
the control circuit controls the deformation of the body based on
the operation state from at least one of the fan and the electronic
device for changing the volume of the groove.
[0007] A fan system is disclosed in an embodiment based on this
disclosure, wherein the fan system is applied to dissipate the heat
from an electronic device, and the fan system comprises: a fan; a
body surrounding the fan, and the body comprises an interior face
and a side face is next to the interior face, wherein the interior
face faces the fan and the interior face is spaced from the fan.
Additionally, the side face comprises a groove, and a sound wave is
transmitted to the groove when the fan is operating. Moreover,
there's a control circuit connected to the body, wherein the
control circuit controls the deformation of the body based on the
operation state from at least one of the fan and the electronic
device for changing the volume of the groove.
[0008] A sound suppression method for the fan system is disclosed
in an embodiment based on this disclosure, wherein the fan system
comprises a fan and a hollow structure, and the sound suppression
method comprises: transmitting a sound wave to an interior of the
hollow structure by the operating of the fan, detecting the
operation state from at least one of the fan and an electronic
device, controlling the deformation of the hollow structure to
change the volume of the interior of the hollow structure based on
the operation state from at least one of the fan and an electronic
device, and finally making the resonance frequency of the hollow
structure approximate to or even equal to a rotation frequency of
the fan.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present disclosure will become more fully understood
from the detailed description given hereinbelow and the
accompanying drawings which are given by way of illustration only
and thus are not limitative of the present disclosure and
wherein:
[0010] FIG. 1 is the schematic diagram of the fan system disposed
in the server in an embodiment.
[0011] FIG. 2 is the schematic diagram of the fan system based on
FIG. 1 in the first embodiment.
[0012] FIG. 3 is the schematic diagram of the hollow structure
based on FIG. 2 for decreasing the noise.
[0013] FIG. 4 is the volume changed in the interior of the hollow
structure based on FIG. 2.
[0014] FIG. 5 is the schematic diagram of the fan system based on
FIG. 1 in the second embodiment.
[0015] FIG. 6 is the schematic diagram of the fan system based on
FIG. 1 in the third embodiment.
[0016] FIG. 7 is the flowchart of the sound suppression method.
[0017] FIG. 8 is the schematic diagram of the fan system disposed
in the server in another embodiment for this disclosure.
[0018] FIG. 9A is the schematic diagram of the fan system based on
FIG. 8 in the first embodiment.
[0019] FIG. 9B is the top view of FIG. 9A.
[0020] FIG. 10 is the top view of the fan system based on FIG. 8 in
the second embodiment.
[0021] FIG. 11 is the schematic diagram of the fan system based on
FIG. 8 in the third embodiment.
[0022] FIG. 12 is the schematic diagram of the fan system based on
FIG. 8 in the fourth embodiment.
[0023] FIG. 13 is the schematic diagram for suppressing the noise
of the fan system based on FIG. 9A.
[0024] FIG. 14 is the flowchart for the sound suppression method of
the fan system based on FIG. 8.
DETAILED DESCRIPTION
[0025] In the following detailed description, for purposes of
explanation, numerous specific details are set forth in order to
provide a thorough understanding of the disclosed embodiments. It
will be apparent, however, that one or more embodiments may be
practiced without these specific details. In other instances,
well-known structures and devices are schematically shown in order
to simplify the drawing.
[0026] Please refer to FIG. 1. FIG. 1 is the schematic diagram of
the fan system disposed in the server in an embodiment. As FIG. 1
shows, a server 100 comprises a fan system 102, a hardware device
104, a central processor unit 106, a temperature sensor 108 and a
circuit board 110. The fan system 102 comprises a fan 112 and a
sound suppressing device 114, and the sound suppressing device 114
is connected between the fan 112 and the hardware device 104. The
fan 112, the hardware device 104 and the temperature sensor 108 are
electrically connected to the circuit board 110, wherein the
temperature sensor 108 detects the inside temperature of the server
100, and the sound suppressing device 114 is electrically connected
to the circuit board 110 by an external wire 116.
[0027] Furthermore, there is no limitation for the quantity of the
sound suppressing device. For an example of two sound suppressing
devices, one of the sound suppressing devices may be disposed
between the fan and the hardware device, and another one of them
may be disposed between the fan and other electronic devices in the
server.
[0028] Please refer to FIG. 1 and FIG. 2. FIG. 2 is the schematic
diagram of the fan system based on FIG. 1 in the first embodiment.
As FIG. 1 and FIG. 2 show, the sound suppressing device 114
comprises a hollow structure 118 and a channel 120 communicated
with the hollow structure 118. In addition, the hollow structure
118 is an integrally formed shell in the shape of a neck container,
and the hollow structure 118 comprises a body 122 and a neck 124.
Also, the body 122 and the neck 124 comprise a thickness T1,
wherein the bottom of the body 122 is connected to the top of the
neck 124 for surrounding and forming an interior 126 of the hollow
structure 118. In this embodiment, the hollow structure 118 is a
resonator, the bottom of the neck 124 includes an opening 128, and
the channel 120 is formed by a top wall 130 and a bottom wall 132.
Moreover, the top wall 130 is connected around the opening 128 of
the neck 124, the two ends of the channel 120 are respectively
extended to the fan 112 and the hardware device 104, and the
channel 120 is communicated with the interior 126 through the
opening 128 of the neck 124. The body 122 has a width W1 and the
neck 124 has a width W2 both in the x-axis direction, and the width
W2 of the neck is smaller than the width W1 of the body 122.
There's no limitation for the shapes of the body 122 and the neck
124. For example, the shape may be a rectangle or a cylinder, but
it must meet the criteria, "the width W2 smaller than the width
W1". As a result, the hollow structure 118 in this embodiment is
able to be replaced by any other kinds of hollow structures.
[0029] Generally, when the shape of a normal metal or alloy is
changed by an external force which is out of the elastic range, its
shape isn't able to be restored by releasing the external force or
heating. In this embodiment, the material of the body 122 and the
neck 124 is shape memory alloy, wherein the shape memory alloy is a
kind of alloy memorizing the original shape according to the
changing phase. When the shape memory alloy in the low temperature
phase (martensite phase) is deformed by an external force that is
limited but larger than the elastic range thereof, the shape is
able to be restored by being heated over the critical temperature
for transforming to the structure in the high temperature phase
(austenite phase). For example, the shape memory alloy may be the
alloy of TiNi series, Cu series or Fe series.
[0030] The fan system 102 further comprises a plurality of control
circuits 134, the control circuits 134 are respectively embed in
the body 122 and the neck 124, and each of the control circuits 134
is electrically connected to the circuit board 110 by the wire 116
for obtaining the rotation speed information of the fan 112 and the
temperature information detected by the temperature sensor 108 in
the server 100. Moreover, each of the control circuits 134
determines whether heats the body 122 and/or the neck 124 based on
the above information. In other embodiment, the control circuit 134
is embed in the body 122 or the neck 124.
[0031] Please refer to FIG. 3, wherein FIG. 3 is the schematic
diagram of the hollow structure based on FIG. 2 for decreasing the
noise. As FIG. 3 shows, the inward sound wave S1 enters the
interior 126 of the hollow structure 118, and the outward sound
wave S2 enters the channel 120 after the outward sound wave S2
leaves the interior 126. Based on the Helmholtz resonance formula,
the resonance frequency of the hollow structure 118 is shown as the
following formula (1):
f=c/2.pi. (A/LV) (1).
[0032] In the above formula (1), "f" is the resonance frequency of
the hollow structure 118, "c" is the speed of sound, "A" is the
cross area of the neck 124, "L" is the length of the neck 124, and
"V" is the volume of the interior 126. In other word, the resonance
frequency f is relative to the cross area A of the neck 124, the
length L of the neck 124 and the volume V of the interior 126.
[0033] The absorption coefficient (.varies.) of the hollow
structure 118 is relative to the absorption ability of the hollow
structure 118, and the absorption coefficient (.varies.) is shown
as the following formula (2):
.varies. = E i - E r E i . ( 2 ) ##EQU00001##
[0034] In the above formula (2), "E.sub.i" is the energy of the
inward sound wave S1, and "E.sub.r" is the energy of the outward
sound wave S2. Therefore, "E.sub.i-E.sub.r" is the sound energy
absorbed by the hollow structure 118, while the absorption
coefficient (.varies.) is between 0 to 1. The more the absorption
coefficient (.varies.) approximates to 1, the better the absorption
ability of the hollow structure 118 is. Additionally, the
absorption coefficient (.varies.) approximates to 1 when the
resonance frequency of the hollow structure 118 approximates to the
frequency of the inward sound wave S1 generated by the operating
fan 112, and the sound volume is decreased obviously after the
phase cancellation against the inward sound wave S1 entering the
interior 126.
[0035] Please refer to FIG. 1 and FIG. 4, wherein FIG. 4 is the
schematic diagram of the volume changed in the interior of the
hollow structure. As FIG. 1 and FIG. 4 show, based on the Helmholtz
resonance formula, the resonance frequency is changed as one of the
cross area A of the neck 124, the length L of the neck 124 and the
volume V of the interior 126 is changed. Hence, through heating the
hollow structure 118 by the control circuit 134 to increase the
thickness of the shape memory alloy from T1 to T2, the volume V of
the interior 126 is decreased. In short, based on the Helmholtz
resonance formula, the resonance frequency is increased when the
volume V of the interior 126 is decreased. In contrast, the
resonance frequency is decreased when the volume V of the interior
126 is increased.
[0036] Please refer to FIG. 5. FIG. 5 is the schematic diagram of
the fan system based on FIG. 1 in the second embodiment. As FIG. 5
shows, the interior 126 of the sound suppressing device 114
comprises a plurality of shape memory alloy planes 136 connected to
each other instead of an integrally formed structure, and the
control circuit 134 is embedded in the shape memory alloy planes
136 and the neck 124.
[0037] Please refer to FIG. 6, wherein FIG. 6 is the schematic
diagram of the fan system based on FIG. 1 in the third embodiment.
As FIG. 6 shows, the neck 124 of the hollow structure 118 from the
sound suppressing device 114 comprises a plurality of shape memory
alloy planes 136 connected to each other instead of an integrally
formed structure, and the control circuit 134 is embedded in the
shape memory alloy planes 136 and the neck 124.
[0038] Please refer to FIG. 1 and FIG. 7 together, wherein FIG. 7
is the flowchart of the sound suppression method for the fan system
based on FIG. 1. As FIG. 1 and FIG. 7 show, the step S101 is
transmitting the sound waves to the interior 126 by the operation
of the fan 112. The step of S102 is detecting the inside
temperature of the server by the temperature sensor 108. The step
S103 is transmitting a temperature signal to the central processor
unit 106 by the temperature sensor 108. The step S104-1 is
transmitting the temperature signal to the fan 112 by the central
processor unit 106, and the step S104-2 is transmitting the
temperature signal to the control circuit 134 by the central
processor unit 106. The step S105 is changing the rotation speed of
the fan 112 according to the temperature signal by the fan. For the
step S106, the control circuit 134 controls the thickness of the
shape memory alloy of the hollow structure 118 for changing the
volume of the interior 126, and making the resonance frequency of
the hollow structure 118 approximate to or even equal to the
rotation frequency of the fan 112.
[0039] The rotation speed of the fan 112 is changed as the inside
temperature of the server 100 is changed, and the fan 112 includes
the rotation frequency corresponded to the rotation speed. The fan
112 generates the sound wave signals with low frequency when the
fan 112 operates in the low rotation speed, and the fan 112
generates sound wave signals with high frequency when the fan 112
operates in the high rotation speed. As FIG. 7 shows, the control
circuit 134 increases the thickness of the shape memory alloy by
heating the shape memory alloy of the hollow structure 118 when the
rotation speed of the fan 112 is gained. Hence, the volume of the
interior 126 is decreased, and the resonance frequency of the
hollow structure 118 is increased through this process. If the
rotation speed of the fan 112 is decreased as the fan 112 operates
for a time period, the control circuit 134 heats the shape memory
alloy of the hollow structure 118 and makes the temperature of the
shape memory alloy be more than its critical temperature. As a
result, the shape memory alloy is transformed to the structure of
the high temperature phase (austenite phase), and making both of
the volume of the interior 126 and the resonance frequency of the
hollow structure 118 return to the original states.
[0040] The hollow structure in this disclosure is able to be
replaced by other structures for implementation of the sound
suppression method. Please refer to FIG. 8. FIG. 8 is the schematic
diagram of the fan system disposed in the server in another
embodiment for this disclosure. As FIG. 8 shows, a server 200
comprises a fan system 202, a hardware device 204, a central
processor unit 206, a temperature sensor 208 and a circuit board
210. The fan system 202 comprises a fan 212 and a body 214, wherein
the body 214 surrounds the fan, and the fan system 202 is disposed
at a side of the hardware device 204. The fan 212, the hardware
device 204, the central processor unit 206, and the temperature
sensor 208 are electrically connected to the circuit board 210.
Also, the body 214 is electrically connected to the circuit board
210 by an external wire 216, and the temperature sensor 208 detects
the inside temperature of the server 200.
[0041] Please refer to FIG. 8 and FIG. 9A together, wherein FIG. 8
and FIG. 9A are the schematic diagrams of the fan system in the
first embodiment. As FIG. 8 and FIG. 9A show, the body 214 of the
fan system 202 is a frame made by the shape memory alloy, wherein
the body 214 surrounds the fan 212 and the body 214 is spaced from
the fan 212 in the y-axis direction. The fan 212 comprises a motor
218 and two blades 220 and 222, and the two blades 220 and 222 are
respectively connected to the two sides of the motor 218. The body
214 comprises an interior face 224, and the interior face 224 is
spaced from the two blades 220 and 222. A plurality of grooves 226
are disposed in the interior face 224, and the grooves 226 are
separated by a plurality of intervals. Also, each of the grooves
226 has a width W3 in the x-axis direction and a depth H1 in the
y-axis direction. When the motor 218 turns the two blades 220 and
222, the airflow is driven by the two blades 220 and 222. Moreover,
when a kind of the sound wave called wind noise is generated during
the air flows through the fan 212 and the body 214, the sound wave
resulting in the wind noise generated by the operating fan 212 is
transmitted to the grooves 226. Additionally, the fan system 202
includes a plurality of control circuits 228 respectively embed in
the body 214, and each of the control circuits 228 controls the
deformation of the body 214 based on the operating state of the fan
212. As a result, the volume of the body 214 and the groove 226 may
be changed by this process.
[0042] FIG. 9B is the top view from FIG. 9A. As FIG. 9B shows, the
grooves 226 arranged between the intervals are disposed in the body
214 in the X-Z plane, and the grooves 226 are in the shapes of
squares with the same length for each side.
[0043] Please refer to FIG. 10, wherein FIG. 10 is the top view
based on the fan system in FIG. 8 in the second embodiment. As FIG.
10 shows, the grooves 230 arranged between the intervals are
disposed on the body 214 in the X-Z plane, and the grooves 230 may
be in square, rectangle, circle, triangle, pentagon and hexagon
shapes.
[0044] Please refer to FIG. 11, wherein FIG. 11 is the schematic
diagram of the fan system based on FIG. 8 in the third embodiment.
As FIG. 11 shows, the interior face 224 comprises a plurality of
the grooves 232 arranged between the intervals, wherein each of the
grooves 232 comprises a first section 234 and a second section 236
in the y-axis direction, and the interior face 224 is closer to the
first section 234 than to the second section 236. Also, the first
section 234 has a width W4 and the second section 236 has a width
W5 both in the x-axis direction, and the width W4 is smaller than
the width W5. The sound wave with the wind noise is transmitted to
the grooves 232 when the fan 212 is operating, and each of the
control circuits 228 controls the deformation of the body 214 based
on the operating state of the fan 212. As a result, the volume of
the groove 232 disposed in the body 214 is able to be changed by
this process.
[0045] Please refer to FIG. 12, wherein FIG. 12 is the schematic
diagram of the fan system based on FIG. 8 in the fourth embodiment.
As FIG. 12 shows, the body 214 of the fan system 202 comprises the
interior face 224 and two side faces 238 and 240 which are next to
the interior face 224. In addition, the interior face 224 faces the
fan 212 and the interior face 224 is spaced from the fan 212,
wherein there is a plurality of grooves 242 disposed in each of the
two side faces 238 and 240, and the sound wave with the wind noise
generated by the operating fan 212 is transmitted to the grooves
242. Also, each of the grooves 242 comprises a first section 244
and a second section 246 in the x-axis direction, and the side face
238 is closer to the first section 244 than to the second section
246. Moreover, the first section 244 has a width W6 and the second
section 246 has a width W7 both in the y-axis direction, wherein
the width W6 is smaller than the width W7. As a result, each of the
control circuits 228 controls the deformation of the body 214 based
on the operating state of the fan 212, and the volume of the groove
242 disposed in the body 214 is able to be changed by this
process.
[0046] Please refer to FIG. 13, wherein FIG. 13 is the schematic
diagram for suppressing the noise of the fan system based on FIG.
9A. When the fan 212 operates at different rotation speeds, the
space between the fan 212 and the bottom of the groove 226 needs to
be adjusted for suppressing the wind noise. For this reason, after
the control circuit 228 adjusts the volume of the groove 226 to a
proper value, the inward airflow S3 generated by the operating fan
212 enters the groove 226 of the body 214 and then is reflected
therefrom. Finally, the sound volume generated by the outward
airflow S4 reflected from the groove 226 is lower than the sound
volume generated by the inward airflow S3.
[0047] Please refer to FIG. 8 and FIG. 14 together, wherein FIG. 14
is the flowchart for the sound suppression method of the fan system
based on FIG. 8. As FIG. 8 and FIG. 14 show, the step S201 is
transmitting the sound waves generated by the operation of the fan
to the groove 226 of the body 214. The step S202 is detecting the
inside temperature of the server 200 by the temperature sensor 208.
The step S203 is transmitting a temperature signal to the central
processor unit 206 by the temperature sensor 208. The step S204-1
is transmitting the temperature signal to the fan 212 by the
central processor unit 206, and the step S204-2 is transmitting the
temperature signal to the control circuit 228 by the central
processor unit 206. The step S205 is changing the rotation
frequency of the fan 212 according to the temperature signal by the
fan 212. The step S206 is controlling the thickness of the shape
memory alloy of the body 214 based on the temperature signal by the
control circuit 228 for changing the volume of the groove 226 of
the body as well as decreasing the energy of the sound wave by
making the sound wave reflect in the groove 226 when the fan 212 is
operating.
[0048] When the inside temperature of the server 200 is changed,
the rotation speed of the fan 212 is relatively changed, and the
fan 112 includes the rotation frequency corresponded to the
rotation speed. The fan 212 generates the sound wave with the low
frequency when the fan 212 rotates in the low rotation speed, and
the fan 212 generates the sound wave with the high frequency when
the fan 212 rotates in the high rotation speed. As FIG. 14 shows,
as the rotation speed of thee fan 212 is increased, the thickness
of the shape memory alloy is raised through heating the shape
memory alloy of the body 214 by the control circuit 228, and the
volume of the groove 226 of the body 214 is decreased. Hence, the
space of the groove 226 is smaller than the original space, and the
reflection effect of the sound wave in high frequency is improved.
If the rotation speed of the fan 212 is decreased as the fan 212
rotates for a time period, the control circuit 228 heats the shape
memory alloy of the body 214 until the temperature of the body is
more than the critical temperature of the shape memory alloy. Thus,
the structure of the shape memory alloy is transformed to the high
temperature phase (austenite phase) for returning to the original
state. As a result, the volume of the groove 226 is returned to the
original volume, and the space of the groove 226 is larger than the
original space, so the reflection effect of the sound wave in low
frequency is improved.
[0049] Based on the fan system disclosed in this disclosure, in
addition to maintenance of the normal airflow between the hardware
device and the fan system, by the properties of the shape memory
alloy and the control circuit, the control circuit is able to
change the volume of the groove based on the rotation frequency of
the fan and/or the temperature of the electronic device. Hence,
even though the fan may operate at different rotation speeds, the
resonance frequency of the groove is able to approximate or even
equal to the rotation frequency of the fan. As a result, the sound
volume generated by the operating fan can be decreased during this
process. On the other hand, by changing the thickness of the body
appropriately through the control circuit, the space between the
fan and the bottom of the groove is able to be maintained in a
proper value, and the wind noise is suppressed by this process.
[0050] The embodiments depicted above and the appended drawings are
exemplary and are not intended to be exhaustive or to limit the
scope of the present disclosure to the precise forms disclosed.
Many modifications and variations are possible in view of the above
teachings.
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