Pumps – Motor driven – Electric or magnetic motor
Reexamination Certificate
2001-01-17
2003-01-21
Walberg, Teresa (Department: 3742)
Pumps
Motor driven
Electric or magnetic motor
C388S816000, C417S356000
Reexamination Certificate
active
06508636
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority benefit of Japanese application serial no. 2000-094303, filed on Mar. 30, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to a freon compressor used for devices such as air-conditioners, refrigerators, showcases or vending machines for juice etc.
2. Description of Related Art
Electromotor devices composed of a direct current (DC) motor are installed within freon compressors used for devices such as air-conditioners, refrigerators, or showcases. The electromotor device consists of a stator and a rotor, and stator windings are wired on the stator. The rotor is then rotated by applying voltages on the stator windings, thereby the electromotor device is driven to operate the freon compressor.
FIGS. 13 and 14
show a conventional stator structure of an electromotor device. As shown in
FIGS. 13 and 14
, a number of teeth
102
are formed on the stator
101
in an equal distance manner, and stator windings
103
are wired across the teeth
102
.
FIG. 15
shows a distribution of the magnetic lines of force of the electromotor device. As shown in
FIG. 15
, the electromotive machine
100
serving as the electromotor device is a direct current (DC) motor, and there are four permanent magnets
105
arranged on the stator
104
in a substantially rectangular shape. The magnetic lines of force of each permanent magnet
105
pass through the teeth
102
in four directions, forming magnetic loops passing through the stator
101
.
FIG. 16
shows a control circuit for the conventional electromotor device. As shown in
FIG. 16
, an alternating current (AC) power source is connected to a rectifier smoothing circuit
33
consisting of a rectifier diode D
1
and a capacitor
35
. The rectifier smoothing circuit
33
is further connected to an inverter circuit
36
consisting of a number of semiconductor switch devices, such as FET transistors SW
1
, SW
2
, SW
3
, SW
4
, SW
5
and SW
6
. The outputs of the inverter circuit
36
are connected to the stator windings
103
of the electromotive machine
100
through three wirings
37
,
38
and
39
. Each of the wirings
37
,
38
and
39
is respectively connected to a position detector
106
via a detecting circuit (not shown) that is used for voltages on the stator windings
103
. In addition, the position detector
106
is further connected to the inverter circuit
36
through a tachometer
107
and an equi-width pulse width modulation (PWM) waveform generator
109
. A conductive phase switch circuit
108
is connected between the position detector
106
and the inverter circuit
36
.
The position detector
106
is used for detecting whether the wirings
37
,
38
and
39
are applied voltages thereon by the inverter circuit
36
, and then the rotation number of the rotor is calculated by the tachometer
107
. According to the calculated rotation number, the equi-width PWM waveform generator
109
generates an equi-width PWM waveform to output to the inverter circuit
36
. Afterwards, the inverter circuit
36
divides the equi-width PWM waveform into three phases (U phase, V phase and W phase) separated by 120 degrees, capable of respectively being transmitted on the wirings
37
,
38
and
39
. The inverter circuit
36
then outputs signals along two of the three wirings
37
,
38
and
39
, such that a magnetic field is generated on any one tooth
102
of the stator windings
103
for driving the electromotor
100
to operate the freon compressor. In addition, the conductive phase switch circuit
108
determines the outputs of the inverter circuit
36
based on the output of the position detector
105
.
FIG. 17
shows operational modes of the electromotor. As shown in
FIG. 17
, the inverter circuit
36
outputs an equi-width PWM waveform (plus) using a KA
1
mode to the U phase wiring (the wiring
37
), and the equi-width PWM waveform (minus) to the V phase wiring (the wiring
38
), by which a current is generated to flow along the black arrow and a magnetic force is generated along the white arrow. Next, the inverter circuit
36
outputs an equi-width PWM waveform (plus) using a KA
2
mode to the U phase wiring (the wiring
38
), and the equi-width PWM waveform (minus) to the W phase wiring (the wiring
39
), by which a current is generated to flow along the black arrow and a magnetic force is generated along the white arrow.
Next, the inverter circuit
36
outputs an equi-width PWM waveform (plus) using a KA
3
mode to the V phase wiring, and the equi-width PWM waveform (minus) to the W phase wiring, by which a current is generated to flow along the black arrow and a magnetic force is generated along the white arrow. The inverter circuit
36
outputs an equi-width PWM waveform (plus) using a KA
4
mode to the V phase wiring, and the equi-width PWM waveform (minus) to the U phase wiring, by which a current is generated to flow along the black arrow and a magnetic force is generated along the white arrow. The inverter circuit
36
outputs an equi-width PWM waveform (plus) using a KA
5
mode to the W phase wiring, and the equi-width PWM waveform (minus) to the U phase wiring, by which a current is generated to flow along the black arrow and a magnetic force is generated along the white arrow.
Next, the inverter circuit
36
outputs an equi-width PWM waveform (plus) using a KA
6
mode to the W phase wiring, and the equi-width PWM waveform (minus) to the V phase wiring, by which a current is generated to flow along the black arrow and a magnetic force is generated along the white arrow. Accordingly, the magnetic force is sequentially rotated such that the rotor
104
is rotated. Thus, as shown in
FIG. 18
, a rotary magnetic field is generated in a manner that the circumference (an electric angle, equal to 360 degrees) is equally divided into six by releasing one of the three phases and then applying voltages on the other two phases for rotating the electromotor
100
.
Therefore, according to the conventional method, the position detector is first used to detect a rotation position for detecting which one of the U-, V- and W-phases is released. For example, during the conductive status in the KA
1
mode, only the magnetic field involving the rotor rotates, and the magnetic field involving the stator is not rotated, therefore, the distribution of the magnetic lines of force is more dense in space and time, causing a high magnetic flux of harmonic wave. The majority of noise results from this high magnetic flux of harmonic wave.
SUMMARY OF THE INVENTION
The object of this invention is to provide an electromotor device in which the distribution of the magnetic lines of forces are stabilized in space and time, and therefore to provide a freon compressor capable of significantly reduced noise.
Therefore, it is an objective of the present invention to provide a freon compressor. The freon compressor comprises a compressor device and an electromotor device. The electromotor device is used to drive the compressor device and consists of a stator and a rotor rotating within the stator. The stator further consists of a stator core and stator windings wired on the stator core, and a three-phase sine alternating current waveform is applied to the stator windings.
The rotor further comprises a rotor core and a plurality of permanent magnets formed within the rotor core. The permanent magnets are arranged in a substantially rectangular configuration. In addition, the permanent magnets can be also divided into four sets of parallel permanent magnets and these four sets of parallel permanent magnets are arranged on the rotor core. The rotor further comprises a rotor core and a plurality of permanent magnets arranged on the surface of the rotor core. The permanent magnets can be magnets made from rare-earth elements, or ferrite. The stator core further comprises at least six to twelve slots thereon, and the stator windings are directly wired on the slots. Freon absorbed and compressed by the compressor device comprises HFC freon or a natural
Izawa Yuuichi
Kato Hideaki
Nomoto Tetsuo
Ogawa Takashi
Fastovsky Leonid
Patents J. C.
Sanyo Electric Co,. Ltd.
Walberg Teresa
LandOfFree
Freon compressor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Freon compressor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Freon compressor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3020687