Title: Synchronous inductance motor, a manufacturing method of the synchronous inductance motor, and a compressor
Abstract: A synchronous inductance motor provided in a rotor includes at least a pair of slit portions forming a two-pole magnetic polar projection having an easy-to-pass direction of the magnetic flux, i.e., q-axis and a difficult-to-pass direction of the magnetic flux, i.e, d-axis which are almost orthogonal and a plurality of slot portions close to an outer circumference in the slit portions and connected to at least an end of the slit portion in a direction of the d-axis for generating inductance torque. Further, conductivity material is filled in the slit portions and the slot portions.
Patent Number: 6,906,448 Issued on 06/14/2005 to Yoshino, et al.
| Inventors:
|
Yoshino; Hayato (Tokyo, JP);
Kawaguchi; Hitoshi (Tokyo, JP);
Takita; Yoshio (Tokyo, JP)
|
| Assignee:
|
Mitsubishi Denki Kabushiki Kaisha (Tokyo, JP)
|
| Appl. No.:
|
290349 |
| Filed:
|
November 8, 2002 |
Foreign Application Priority Data
| Nov 12, 2001[JP] | 2001-346149 |
| Current U.S. Class: |
310/216; 310/212 |
| Intern'l Class: |
H02K 001/27; H02K021/14; H02K019/14 |
| Field of Search: |
310/216,211,91,212,156.47
|
References Cited [Referenced By]
U.S. Patent Documents
| 2483848 | Oct., 1949 | Saretzky.
| |
| 2975310 | Mar., 1961 | Armstrong et al.
| |
| 3629628 | Dec., 1971 | Rank et al.
| |
| 4064410 | Dec., 1977 | Roach.
| |
| 5831367 | Nov., 1998 | Fei et al.
| |
| Foreign Patent Documents |
| 63-217957 | Sep., 1988 | JP.
| |
| 5-316701 | Nov., 1993 | JP.
| |
| 10-127023 | May., 1998 | JP.
| |
| 2001-73948 | Mar., 2001 | JP.
| |
| 2001/-186735 | Jul., 2001 | JP.
| |
Primary Examiner: Nguyen; Tran
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier & Neustadt, P.C.
Claims
1. A synchronous inductance motor comprising:
at least a pair of continuous slit portions provided in a rotor, the slit portions
being substantially of a linear shape and configured to form two-pole magnetic
polar projection having an easy-to-pass direction of the magnetic flux, i.e., d-axis,
and a difficult-to-pass direction of the magnetic flux, i.e, q-axis, said axes
being substantially orthogonal to each other; and
a plurality of slot portions arranged close to an outer circumference in the
slit portions and connected to at least an end of the slit portions in a direction
of the d-axis, the slot portions being configured to generate an induction torque,
wherein the slit portions and the slot portion are filled with conductivity material.
2. The synchronous inductance motor of claim 1, wherein the slit portions are
substantially parallel to the d-axis.
3. The synchronous inductance motor of claim 1, wherein the slot portions are
separated radially with a substantially equal interval.
4. The synchronous inductance motor of claim 1, wherein the slit portions and
the slot portions are separated.
5. The synchronous inductance motor of claim 1, wherein end-rings provided at
both ends of the rotor in an axial direction and the conductivity material filled
in the slit portions and the slot portions are integrated by die-casting.
6. The synchronous inductance motor of claim 1 comprising a shaft provided in
the rotor, for transferring rotation power of the rotor, wherein the shaft is made
of non-magnetic material.
7. The synchronous inductance motor of claim 6 comprising end-rings made of the
non-magnetic material, provided at both ends of the rotor in an axial direction,
wherein the shaft is integrated with the end-rings.
8. A compressor comprising the synchronous inductance motor of claim 1.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a synchronous inductance motor which starts using
inductance torque and performs a synchronous operation using reluctance torque
and its manufacturing method.
2. Description of the Related Art
FIG. 16 illustrates a sectional view of a motor according to the related art
disclosed in Japanese Unexamined Patent Publication HEI 10-127023. In FIG. 16,
a rotor
11, a slit
13, and a stator
20 are illustrated.
In FIG. 16, since a multiplicity of slits
13 in a linear shape is provided
in the rotor
11, a d-axis which is an easy-to-pass direction of magnetic
flux and a q-axis which is a difficult-to-pass direction of magnetic flux are shifted
by
90 degrees each other, and the motor includes a two-pole magnetic polar
projection. The slit
13 does not include a conductivity member (secondary
conductor), and the slit
13 includes an air layer.
FIG. 17 illustrates a sectional view of a rotor of a synchronous motor packaged
in a compressor according to the related art disclosed in Japanese Unexamined Patent
Publication 2001-73948. In FIG. 17, a rotor
105, slots
301 and
304
filled with aluminum, and permanent magnets
300a and
300b
are illustrated. In FIG. 17, a two-pole rotor includes the permanent magnets
300a and
300b arranged so that S pole, S pole, N pole,
and N pole are arranged in a circumference direction of the rotor
105.
The motor according to the related art is structured as stated, and there are
following problems. Since an inside of the slit
13 in the motor illustrated
in FIG. 16 is not filled with the conductivity member, the rotor
11 does
not have a secondary conductor in a squirrel-cage shape. Therefore, it is necessary
that the stator generates a magnetic field appropriate for a position of the rotor
11, and it becomes necessary to use a mechanism for detecting a rotor position
and a drive circuit. When the mechanism for detecting the rotor position is provided,
a cost of the motor goes up, and a size of the motor becomes larger. Further, since
the drive circuit is used, a system for driving the motor becomes large-scale,
and an expensive control device becomes necessary. Hence, a cost goes up.
Further, if the position of the rotor is not detected accurately, it is
impossible to stably perform the synchronous operation. Therefore, there is a problem
that the cost further goes up. As explained with reference to FIG. 17, in the synchronous
motor packaged in the compressor according to the related art, the slots
301
and
304 are filled with aluminum and the rotor
105 includes the secondary
conductor in the squirrel-cage shape. Hence, the motor can start easily. However,
since the synchronous operation is performed using the permanent magnets
300a
and
300b which are expensive, there is a problem that the cost
of the motor and the cost of the compressor tend to go up. Further, since the rotor
105 includes the permanent magnets
300a and
300b,
when the synchronous motor is dismantled, the permanent magnets attract a dismantling
device, and a dismantling operation becomes difficult.
SUMMARY OF THE INVENTION
This invention is intended to obtain a synchronous inductance motor in a low
price, which can start easily, an apparatus for manufacturing the synchronous inductance
motor, and a manufacturing method of the synchronous inductance motor. Further,
this invention is intended to obtain the reliable synchronous inductance motor,
the apparatus for manufacturing the synchronous inductance motor, and the manufacturing
method of the synchronous inductance motor. Further, this invention is intended
to provide the synchronous inductance motor which can be recycled and dismantled
easily, the apparatus for manufacturing the synchronous inductance motor, and the
manufacturing method of the synchronous inductance motor.
According to an aspect of this invention, a synchronous inductance motor
includes at least a pair of slit portions provided in a rotor, for forming two-pole
magnetic polar projection having an easy-to-pass direction of the magnetic flux,
i.e., d-axis and a difficult-to-pass direction of the magnetic flux, i.e., q-axis
which are almost orthogonal, and a plurality of slot portions arranged close to
an outer circumference in the slit portions and connected to at least an end of
the slit portions in a direction of the d-axis, for generating induction torque.
Further, the slit portions and the slot portion are filled with conductivity material.
According to another aspect of this invention, a manufacturing method of
a synchronous inductance motor which has a rotor iron core includes non-adjacent
slit-slot punching for punching non-adjacent slit-slots among a plurality of slit-slots
including a slot portion for generating inductance torque and a slit portion for
generating reluctance torque connected each other, adjacent slit-slot punching
for punching a slit-slot existing between the non-adjacent slit-slots punched in
the non-adjacent slit-slot punching, and rotor outer circumference punching for
punching an outer circumference of the rotor iron core.
Further features and applications of the present invention will become apparent
from the detailed description given hereinafter. However, it should be understood
that the detailed description and specific examples, while indicating preferred
embodiments of the invention, are given by way of illustration only, since various
changes and modifications within the spirit and scope of the invention will become
apparent to those skilled in the art from this detailed description.
Other objects features, and advantages of the invention will be apparent from
the following description when taken in conjunction with the accompany drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross-sectional view of a synchronous inductance motor in Embodiment
1 of this invention;
FIG. 2 shows a sectional view of a rotor in Embodiment 1 of this invention;
FIG. 3 shows a perspective view of the rotor in the synchronous inductance motor
in Embodiment 1 of this invention;
FIG. 4 shows a sectional view of another rotor in the synchronous inductance
motor in Embodiment 1 of this invention;
FIG. 5 shows a sectional view of another rotor in the synchronous inductance
motor in Embodiment 1 of this invention;
FIG. 6 shows a sectional view of another rotor in Embodiment 1 of this invention;
FIG. 7 shows a sectional view of another rotor in Embodiment 1 of this invention;
FIG. 8 shows a sectional view of another rotor in Embodiment 1 of this invention;
FIG. 9 shows a sectional view of another rotor in Embodiment 1 of this invention;
FIG. 10 shows a sectional view of the rotor in the synchronous inductance motor
in Embodiment 2 of this invention;
FIG. 11 shows a sectional view of the rotor for explaining widths of magnetic
material and non-magnetic material;
FIG. 12 shows a perspective view of the rotor in Embodiment 2 of this invention;
FIG. 13 shows a sectional view of the rotor in Embodiment 2 of this invention;
FIG. 14 illustrates a manufacturing process of the rotor in Embodiment 3 of
this invention;
FIG. 15 shows a flow chart of manufacturing a rotor iron core in Embodiment
3 of this invention;
FIG. 16 shows a sectional view of the motor according to the related art;
FIG. 17 shows a sectional view of the rotor of the synchronous motor according
to the related art; and
FIG. 18 shows a sectional view of another rotor in Embodiment 1 of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
With reference to drawings, Embodiment 1 of this invention is explained. FIG.
1 shows a cross-sectional view of a synchronous inductance motor in Embodiment
1 of this invention. FIG. 2 shows a sectional view of a rotor in Embodiment 1 of
this invention. FIG. 3 shows a perspective view of the rotor of the synchronous
inductance motor in Embodiment 1 of this invention. In FIG. 1, a stator iron core
1 includes an electromagnetic steel plate which is a magnetic portion. A
plurality of electromagnetic steel plates is layered to constitute a stator.
Further, a coil
2 is wound in an inside of a slot portion
1a
of the stator iron core
1, and a rotor iron core
3 includes an
electromagnetic steel plate which is a magnetic portion. A plurality of electromagnetic
steel plates is layered to constitute a rotor
30 illustrated in FIG. 3.
A pair of slit-slots
4 includes slit portions (
4a,
40a,
etc.) and slot portions (
4b,
4c,
40b,
40c, etc.), and of which insides are filled with conductivity members
made of aluminum material. A shaft
5 is fixed to the rotor
30 using
press fits, shrink fits, etc. into a through-hole
5a for the shaft
provided at a center of the rotor iron core
3.
In FIG. 2, the plurality of slot portions
4b,
4c,
40b,
40c,
41, etc. in the slit-slots
4
are arranged radially with respect to the center of the rotor iron core
3
and almost evenly. The plurality of slot portions generates inductance torque.
The slot portions
4b and
4b arranged radially are connected
linearly and continuously to be almost parallel to the d-axis by the slit portion
4a. The slot portions
40b and
40b are
connected linearly and continuously to be almost parallel to the d-axis by the
slit portion
40a. Therefore, the d-axis which is the easy-to-pass
direction of the magnetic flux and the q-axis which is the difficult-to-pass direction
of the magnetic flux can be obtained. The slit portion
4a is provided
so that the d-axis and the q-axis cross almost at the center of the rotor and the
d-axis and the q-axis are orthogonal, and a two-pole magnetic polar projection
is formed. Specifically, the slot portions are connected to both ends of the slit
portion in a longitudinal direction (direction of the d-axis).
In the slit-slots
4, the slit portions
4a and
40a
are provided. The slit portion
4a and the slit portion
40a
in a linear shape are arranged in both sides of the d-axis at equidistant positions
from the d-axis which passes almost the center of the rotor iron core
3.
The slit portion
4a and the slit portion
40a are provided
in a pair so that the slit portion
4a and the slit portion
40a
are almost parallel. In FIG. 2, the easy-to-pass direction of the magnetic
flux is illustrated as the d-axis and the difficult-to-pass direction of the magnetic
flux is illustrated as the q-axis. The slot portions
4c and
4c
in the direction of the q-axis are connected by a slit portion
4d
which is almost parallel to the q-axis. The slot portions
4c and
4c and a slit portion
4d form a "U" shape.
Therefore, after the rotor iron core
3 is punched, a projection
portion
3c of the rotor iron core
3, projecting toward a center
direction, is formed in the slot portions
4c and
4c in
the direction of the q-axis and the slit portion
4d. (Similarly,
the projection portion
3c of the rotor iron core
3, projecting
toward the center direction, is formed in the slot portions
40c and
40c in the direction of the q-axis and a slit portion
40d.)
In FIG. 3, the rotor
30 is illustrated. At both ends of the rotor iron
core
3 layered, end-rings
6 which are conductivity members made of
the aluminum material are provided by die-casting aluminum. A secondary conductor
in the squirrel-cage shape is formed out of the aluminum material which is filled
in the inside of the slot portions
4b of the slit-slot
4 of
the rotor
30 and end-rings
6 provided at the both ends of the rotor
iron core
3 layered. When the current flows into the secondary conductor,
the inductance torque is generated, and the motor is started.
Specifically, a conductivity member made of non-magnetic material,
e.g., the aluminum material, etc. is filled in the slot portion, and secondary
current flows into the slot portion for generating the inductance torque at starting
time and during asynchronous operation. Like in the slot portion, the conductivity
member made of the non-magnetic material, e.g., aluminum material, etc. is filled
in the slit portion. In this embodiment, the slot portion and the slit portion
are connected and integrated, and the slit-slot is formed by punching the slot
portion and the slit portion.
The aluminum material filled in the slit-slot
4 of the rotor
30
is the non-magnetic material. Further, since the slit-slot
4 has directionality
(the easy-to-pass direction of the magnetic flux (d-axis) and the difficult-to-pass
direction of the magnetic flux (q-axis) are shifted by a mechanical angle of 90
degrees each other), the magnetic flux created in the stator iron core
1
includes the two-pole magnetic polar projection depending on a position of the rotor.
In this embodiment, the d-axis and the q-axis are shifted by the mechanical angle
of 90 degrees each other, and the synchronous inductance motor with two-poles is
constituted. Since the slot portions
4b and
40b are
provided, even if the synchronous inductance motor is operated by connecting the
coil
2 of the stator iron core
1 to commercial electric power source
in 50 Hz or 60 Hz, a special starting device is not necessary for starting, and
a motor at a low cost can be realized. Further, since the slit portions
4a
and
40a are provided to include the two-pole magnetic polar projection,
the synchronous operation is possible. Further, a rotation number at a time of
operation can be increased up to a synchronous rotation number of 3000 (rpm) or
3600 (rpm) as no slip factor exists like in the inductance motor.
Since a number of poles is two, it is possible to increase the rotation number
compared with the rotation number in a case when the number of the poles is four.
Specifically, in a structure with four poles, when commercial electric power source
in 50 Hz and 60 Hz is used, the rotation number can be increased only to 1500 (rpm)
and 1800 (rpm) which is half of the rotation number in a case of two poles even
in a synchronous operation. However, in a structure of two poles in this embodiment,
it is possible to increase the rotation number up to 3000 (rpm) and 3600 (rpm).
Accordingly, it is possible to increase the rotation number of the motor and realize
a motor with high output power.
The rotor of the synchronous inductance motor according to this invention can
be manufactured by die-casting aluminum as the inductance motor according to the
related art is manufactured. Therefore, a cost of manufacturing the synchronous
inductance motor according to this embodiment does not go up compared with a cost
of manufacturing the inductance motor according to the related art.
Further, since the slot portions
4b and
40b are
placed radially at almost equal intervals on an outer circumference of the rotor
3, it is possible to increase the inductance torque. Therefore, the motor
can start stably and reach the synchronous operation. Hence, it is possible to
realize the reliable synchronous inductance motor.
As stated, the rotor includes the plurality of slot portions arranged close to
the outer circumference for generating the inductance torque, and a pair of slit
portions connecting the plurality of slot portions so that the d-axis which is
the easy-to-pass direction of the magnetic flux and the q-axis which is the difficult-to-pass
direction of the magnetic flux exist. Further, since the two-pole magnetic polar
projection is formed in the rotor by filling the inside of the slot portion and
the inside of the slit portion with the aluminum material which is conductivity
material, the synchronous motor which can start without using a special starting
device can be realized at a low cost. Further, since the two-pole magnetic polar
projection is included, the synchronous operation is possible, and the rotation
number at the time of operation can be the synchronous rotation number as the slip
factor does not exist like in the inductance motor.
Further, since the pair of slit portions is almost in the linear shape,
the magnetic flux can pass through the slit portions easily, and an efficient motor
can be realized. Further, since the pair of slit portions is almost parallel to
the d-axis which is the easy-to-pass direction of the magnetic flux, the magnetic
flux can pass through the slit portions easily. Further, it is possible to suppress
a rise in temperature of the motor, and the reliable motor without an incidence
like burning the coil, etc. can be realized.
FIGS. 4 and 5 show sectional views of another rotor in the synchronous inductance
motor in Embodiment 1 of this invention. For the portions equivalent to the portions
in FIGS. 1-3, same signs are used, and explanations are omitted. In FIGS. 4 and
5, the slot portions
4c and
4c in the direction of
the q-axis illustrated in FIG.
2 and the slit portion
4d connecting
the slot portions (slot portions
40c and
40c and the
slit portion
40d connecting the slot portions
40c)
are integrated into a slit-slot
4e (
40e).
By integrating them, it is possible to punch the slot portions
4c and
4c in the direction of the q-axis and the slit portion
4d
(slot portions
40c and
40c and the slit portion
40d) as a single slot portion. Therefore, a structure of a blade
for punching becomes simple, and a punching device can be obtained at a low cost.
Further, in a case illustrated in FIG. 2, the slot portions
4c and
4c and the slit portion
4d form a U-shape, and there
is a possibility that the projection portion
3c projecting toward
the center is twisted after punching and the accuracy in punching the rotor iron
core
3 drops. However, when the slot portions
4c and
4c
in the direction of the q-axis and the slit portion
4d (slot
portions
40c and
40c and the slit portion
40d)
are integrated into a single slot portion as illustrated in FIG. 4, there is no
projection portion
3c. Hence, the accuracy in punching the rotor
iron core
3 can be improved.
Since the slot portions are placed radially and almost evenly in the rotor
30 of the synchronous inductance motor of FIG.
2 and FIG. 4, it is
possible to start the motor stably like the inductance motor. Further, since the
slot portions in the direction of the q-axis and the slit portion are integrated
into a slot portion as illustrated in FIG. 4, characteristics on entering the synchronous
operation after starting the motor is improved, and it becomes possible to operate
stably at the synchronous rotation number. Hence, the efficient motor can be realized.
Further, since the characteristics on entering the synchronous operation is improved,
it is possible to suppress vibrations and noise caused by the torque during asynchronous operation.
FIGS. 6 and 7 show sectional views of another rotor of this embodiment. In
FIGS. 6 and 7, same signs are used for the portions equivalent to the portions
in FIG. 2, FIG.
4 and FIG. 5, and explanations are omitted. The slot portion
41 in the direction of the d-axis illustrated in FIG. 2 is omitted in the
rotor illustrated in FIGS. 6 and 7. Further, insides of the slot portions
4b
and
40b in the slit-slot
4 provided in the most inner
position among pairs of slit-slots which are almost parallel to the d-axis project
inward than extended lines of the pair of slit portions
4a and
40a
in the linear shape which are almost parallel so that the magnetic flux can
easily pass in the direction of the d-axis. Accordingly, magnetic resistance in
the direction of the d-axis is reduced.
Specifically, since the slot portion is not provided within a range
of an area where straight lines which are parallel to the d-axis meet or touch
the through-hole
5a for a shaft of the rotor iron core
3 (the
slot portion
41 illustrated in FIG. 2, FIG.
4 and FIG. 5 is not provided),
the magnetic flux can pass easily in the direction of the d-axis, and the magnetic
resistance in the direction of the d-axis is reduced. Further, since the slit portion
is not provided within the range of the area where the straight lines which are
parallel to the d-axis meet or touch the through-hole
5a for the
shaft of the rotor iron core
3 and the slot portions
4b and
40b of the slit-slot
4 which is provided in the most inner
position do not project toward a direction of the through-hole
5a of
the shaft than the slit portions
4a and
40a, the magnetic
flux can pass easily in the direction of the d-axis, and the magnetic resistance
in the direction of the d-axis is reduced.
The synchronous motor can generate larger reluctance torque when a difference
between inductance Lq of a stator coil measured from a direction of the q-axis
and inductance Ld of a stator coil measured from a direction of the d-axis is larger.
Therefore, when the slot portion
41 in the direction of the d-axis is omitted
and slot portions of two slit-slots
4 provided in the most inner position
among the slit-slots do not project to an inside of the slit portion as in this
embodiment, magnetic resistance in the direction of the d-axis is reduced. Accordingly,
large reluctance torque can be generated, and it is possible to realize the synchronous
inductance motor with high output power. The slot portion
41 in the direction
of the d-axis is omitted. However, remaining slot portions are placed radially
also in this case. Therefore, a separate starting device, etc. is not necessary.
Accordingly, the reliable synchronous inductance motor of which starting performance
is sufficient can be realized at a low cost.
FIG. 18 shows a sectional view of another rotor of this embodiment. In FIG.
18, same signs are used for the portions equivalent to the portions in FIG. 2,
FIGS. 4-7, and explanations are omitted. In the rotor illustrated in FIG. 18, slits
9a-9d are provided so that the magnetic flux can pass
easily in an area which is separate from the d-axis in vertical directions in FIG.
18 like the magnetic flux passing on the d-axis.
Accordingly, it becomes possible to further reduce the magnetic resistance
and generate large reluctance torque. Consequently, the efficient synchronous inductance
motor with high output power can be realized.
FIG. 8 shows a sectional view of another rotor of this embodiment. In FIG. 8,
same signs are used for the portions equivalent to the portions in FIG. 2, FIGS.
4-7, and explanations are omitted. In the rotor illustrated in FIG. 8, portions
corresponding to the slot portions
4b and
40b of the
slit-slot
4 provided in the most inner position among pairs of slit-slots
which are almost parallel to the d-axis of the rotor are omitted, and the slit
portions
4a and
40a are extended to positions of the
slot portions
4b and
40b linearly.
Accordingly, since there is no slot portion of the slit-slot
4
provided in the most inner position, the aluminum material used for filling is
less. Hence, the motor can be realized at a low cost. Further, since a shape of
the slit-slot becomes simple, a die for punching can be simplified, and the cost
can be reduced. Further, passage of the magnetic flux created at the stator can
be improved, and the motor can be operated efficiently. Particularly, a shape of
the slit-slot
4 which is closest to the shaft
5 is almost parallel
to the d-axis, the passage of the magnetic flux can be further improved, and the
efficient motor can be realized. Therefore, the rise in temperature due to loss
in the motor can be reduced, and the efficiency of the motor can be improved. Remaining
slot portions are placed radially also in this case. Therefore, the separate starting
device, etc. is not necessary, and starting performance is sufficient.
It is also possible to separate the slit portions (
4a,
4d,
40a,
40d, etc.) and the slot portions (
4b,
4c,
40c,
40d, etc.) in the slit-slot.
FIG. 9 shows a sectional view of another rotor of this embodiment. In FIG. 9, same
signs are used for the portions equivalent to the portions in FIG. 2, FIGS. 4-8,
and explanations are omitted. In the rotor illustrated in FIG. 9, the slit portions
(
4a,
4d,
40a,
40d, etc.)
and the slot portions (
4b,
4c,
40c,
40d,
etc.) in the slit-slot in FIG. 2 are separated.
In FIG. 9, the slit portions
4a,
4d,
40a,
and
40d are arranged to obtain the d-axis which is the easy-to-pass
direction of the magnetic flux and the q-axis which is the difficult-to-pass direction
of the magnetic flux, and the reluctance torque is generated. The slot portions
4b,
4c,
40b,
40c, and
41
are arranged radially with respect to the center of the rotor iron core
3
and almost evenly, and the inductance torque is generated.
The slit portion
4a and the slot portion
4b are separated,
and the slit portion
40a and the slot portion
40b are
separated. The slit portion
4d and the slot portion
4c
are separated, and the slit portion
40d and the slot portion
40c are separated.
By separating the slit portion and the slot portion, it becomes possible to fill
the slit portion and the slot portion with respective members. For example, the
slot portion can be filled with the aluminum material by die-casting, etc., and
the slit portion can be filled with another member, e.g., copper, etc. by die-casting,
etc. In this case, the member filled in the slit portion and the member filled
in the slot portion can be separated by filling the slot portion with the member
which is different from the member filled in the slit portion after covering the
slit portion for preventing the member filled in the slot portion from flowing
into the slit portion.
As stated, since the slit portion and the slot portion are separated, respective
members can be filled in the slit portion and the slot portion. Therefore, the
member for filling can be selected more flexibly, and the cost can be reduced.
Further, it is possible to increase flexibility in characteristics of the motor.
It is not necessary the slit portion is filled with the conductivity member.
It
is possible to fill the slot portion with the conductivity member and fill the
slit portion with a low permeability member. A similar effect can be realized by
inserting a magnet with the low magnetic passing rate into the slit portion. In
this case, an opening in a size of the magnet is provided in the member filled
for inserting the magnet, and the magnet is inserted to the opening. In this case,
the slit portion includes a fitting portion which is in a shape of a concave or
a convex, and the magnet fitted into the fitting portion is in a shape of a concave
or a convex so that the magnet and the slit portion are fitted each other. When
the magnet is inserted so that the magnet is fitted into the slit portion, it becomes
easy to determine an insertion position of the magnet, further the magnet can be
fixed surely.
As a method for forming the secondary conductor in the squirrel-cage shape, there
is a method for inserting an aluminum bar which is processed in a shape of the
slit-slot
4 to each of the slit-slots
4 and welding a processed end-ring
to the aluminum bar inserted to the slit-slot
4. However, since it is necessary
to process the aluminum bar to form a slit in a complex shape, a cost goes up slightly.
As another method for forming the secondary conductor in the squirrel-cage shape,
there is a method for providing the aluminum material in an inside of the slit-slot
to be integrated with the end-rings by die-casting aluminum. When the rotor
30
is manufactured in this method, the aluminum material filled in the slit-slot
4
and the end-rings
6 provided at both ends of the rotor
30 are formed
to be integrated by die-casting. Hence, the efficiency in manufacturing is improved,
and time for manufacturing can be reduced.
When the end-rings and the aluminum material in the slit-slot
4 are fixed
each other by welding, the rotor iron core
3 and the secondary conductor
in the squirrel-cage shape become less integrated depending on a method for welding,
a position welded, etc. Since it is impossible to maintain the strength against
centrifugal force, there is a possibility that the rotor
30 is damaged during
operation. However, by integrating the end-rings with the aluminum material in
the slit-slot
4 by die-casting, the rotor iron core
3 and the secondary
conductor (aluminum material) in the squirrel-cage shape are integrated. Hence,
the structural strength is improved, and the reliable motor can be realized.
As stated, in this embodiment, the rotor is formed by integrating the end-rings
provided at both ends of the rotor in the direction toward the shaft with the conductivity
material made of the aluminum material filled in the slit portion and the slot
portion by die-casting aluminum. Therefore, the structural strength is improved
compared with a case of fixing the end-rings and the aluminum material in the slit-slot
4 by welding, and it becomes possible to realize the reliable motor.
Since the synchronous inductance motor in this embodiment does not use a permanent
magnet like the synchronous motor according to the related art, the dismantling
device is not attracted by a permanent magnet. Hence, it becomes easy to dismantle
the motor, and the motor which can be recycled can be realized.
In this embodiment, explanations are made on a case in which the pair of the
slit
portions includes four slit portions. However, it is not necessary that the slit
portions are four. Further, as the conductivity material, the aluminum material
was used for explanation. However, a similar effect can be realized using other
materials, e.g., copper, copper alloy, brass, stainless steel material, etc. For
example, when the copper is used as the material, since the copper has lower resistance
rate than the aluminum material, the resistance of the secondary conductor in the
squirrel-cage shape becomes lower. Hence, the characteristics on operation from
starting to entering synchronization can be improved.
Since the motor has two poles in this embodiment, the rotation number can be
twice the rotation number in a case of four poles. Therefore, when the motor is
packaged in a compressor, the compressor with high output power can be realized.
Further, since there is no slip factor, the rotation number can be increased, and
the motor and the compressor with high output power can be realized compared with
a case of using the inductance motor. Further, compared with the case of using
the synchronous motor without the magnet, a large-scale starting device is not
necessary. Hence, the motor and the compressor can be realized at the low cost.
Further, compared with the case of using the synchronous motor including the magnet,
the cost is low as the magnet is not necessary. Further, the dismantling device
is not attracted by the magnet at a time of dismantling. Hence, the motor and the
compressor which can be recycled easily can be realized.
In the synchronous inductance motor of this embodiment, time from starting to
entering the synchronous rotation number can be shortened, and the performance
is good. Therefore, the synchronous inductance motor with low vibrations and low
noise can be realized. When this synchronous inductance motor is packaged, the
compressor with low vibrations and low noise can be realized. Further, since the
motor according to this embodiment and the compressor in which this motor is packaged
are with low vibrations, when the motor and the compressor are applied to a freezer
or an air conditioner, the reliable freezer or air conditioner in which a pipe
is not cracked due to pipe vibrations can be realized. Further, since the motor
according to this embodiment and the compressor in which this motor is packaged
are with low vibrations and low noise, when the motor and the compressor are applied
to the freezer and the air conditioner, a vibration-preventive device and a noise-preventive
device are not necessary. Hence, the reliable freezer and air conditioner can be
realized at the low cost.
Embodiment 2
FIG. 10 illustrates a sectional view of the rotor in the synchronous inductance
motor showing Embodiment 2 of this invention. For the portions equivalent to the
portions in Embodiment 1, same signs are used and explanations are omitted. In
this embodiment, the non-magnetic material is used for the shaft of the rotor explained
in Embodiment 1.
In FIG. 10, the rotor iron core
3 is illustrated. Electromagnetic steel
plate which is the magnetic material is used for the rotor iron core
3,
and the electromagnetic steel plate is layered to constitute the rotor
30
illustrated in FIG.
3. Slit-slots
4 and
42 are filled with
the conductivity member made of the non-magnetic material, e.g., aluminum material,
etc. Slit portions
4a and
42a and slot portions
4b
and
42b are also illustrated. A width L of the rotor iron core
3 which is the magnetic material between the slit portion
4a and
the slit portion
42a and a width M of the rotor iron core
3
which is the magnetic material between the shaft
50 and the slit portion
4a are illustrated. It is not necessary that the slit portions
4a
and
42a are in the linear shape as explained in Embodiment 1.
The slit portions
4a and
42a are in a rounded shape
opened toward the direction of the d-axis to hold a shaft
50 at a center.
The non-magnetic material, e.g., aluminum material, stainless steel, etc. is
used for the shaft
50. The magnetic material, e.g., iron, etc. is used for
the shaft
5 of the rotor explained in Embodiment 1, and the shaft
5
is fixed to the through-hole
5a for the shaft by shrink-fitting,
press-fitting, etc. Therefore, it is impossible to provide the slit portion in
the shaft
5, and in a ratio between the magnetic material and the non-magnetic
material measured from a direction of the q-axis, a ratio of the magnetic material
is more than a ratio of the non-magnetic material by an amount of the shaft
5
which is quite large. Hence, there are cases in which the motor does not operate
in an efficient condition. It is desirable that the ratio between the magnetic
material and the non-magnetic material becomes a determined ratio which is efficient
according to a number of poles, etc. and the ratio should be selected to reduce
an input to the motor through analysis and experiment.
In this embodiment, the ratio between the magnetic material and the non-magnetic
material for improving the efficiency of the motor is obtained through experiment,
and it is found that the determined ratio should be magnetic material:non-magnetic
material=1:1 (ratio of the magnetic material and ratio of the non-magnetic material
are almost equal). Therefore, the non-magnetic material is used for the shaft
50
to increase a portion of the magnetic material in a portion besides the shaft
50
so that the ratio becomes closer to magnetic material:non-magnetic material=1:1.
When the magnetic material, e.g., iron, etc. is used for the shaft
5, it
is necessary that a portion of the magnetic material besides the shaft
5
is reduced and a portion of the non-magnetic material (slit portion
4) is
increased so that the ratio of the magnetic material and the ratio of the non-magnetic
material are almost equal.
For realizing this, it is necessary to reduce the width L and the width M as
illustrated in FIG.
11. FIG. 11 shows a sectional view of the rotor for
explaining widths of the magnetic material and the non-magnetic material. In FIG.
11, for the portions equivalent to the portions in Embodiment 1, same signs are
used, and explanations are omitted. In FIG. 11, electromagnetic steel plate which
is the magnetic material is used for the rotor iron core
3, and the electromagnetic
steel plate is layered to constitute the rotor
30 illustrated in FIG.
12.
The slit-slots
4 and
42 are filled with the conductivity material
made of the non-magnetic material, e.g., aluminum material. The slit portions
4a
and
42a and the slot portions
4b and
42b
are also illustrated. The width L of the rotor iron core
3 which is
the magnetic material between the slit portion
4a and the slit portion
42a and the width M of the rotor iron core
3 which is the
magnetic material between the shaft
50 and the slit portion
4a
are illustrated.
In FIG. 11, it is impossible to reduce the width L of the rotor iron core
3
which is the magnetic material between the slit portion
4a and the
slit portion
42a and the width M of the rotor iron core
3
which is the magnetic material between the shaft
50 and the slit portion
4a to avoid deformation by punching and to maintain the strength
of the rotor. Therefore, the ratio of the magnetic material is more than the ratio
of the non-magnetic material in the direction of the q-axis, and there is a possibility
that the motor does not operate in an efficient condition.
However, in this embodiment, the non-magnetic material, e.g., the stainless
material is used for the shaft
50 as illustrated in FIG.
10. Unlike
FIG. 11, the non-magnetic material is used for the shaft
50. Therefore,
it is necessary to increase the ratio of the magnetic material by increasing the
width L of the rotor iron core
3 which is the magnetic material between
the slit portion
4a and the slit portion
42a and the
width M of the rotor iron core
3 which is the magnetic material between
the shaft
50 and the slit portion
4a.
Therefore, when the non-magnetic material is used for the shaft
50
as in this embodiment, the width L and the width M can be increased as illustrated
in FIG.
10. Hence, the deformation of the rotor iron core
3 by punching
can be prevented and the strength of the rotor
30 can be maintained. Further,
since the width M which is a portion for holding the shaft can be increased, the
strength in holding the shaft can be improved, and the shaft
50 does not
come out from the rotor
30. Therefore, the synchronous inductance motor
which is reliable and efficient can be realized.
FIG. 12 illustrates a perspective view of the rotor in Embodiment 2 of this
invention. FIG. 13 shows a sectional view of the rotor illustrating Embodiment
2 of this invention. In FIGS. 12 and 13, for the portions equivalent to the portions
in Embodiment 1, same signs are used, and explanations are omitted. In FIG. 12,
the rotor
30 includes the rotor iron core
3 which is layered in an
axial direction. End-rings
55 are provided at both ends of the rotor iron
core
3 layered, and a shaft
55a made of non-magnetic material,
e.g., aluminum material is integrated with the end-rings
55 by die-casting,
etc. In FIG. 13, each of the slit-slots
4,
42,
43, and
44
are pairs of slit-slots provided with respect to the d-axis. As explained in Embodiment
1, the slit-slot includes the slit portion and the slot portion, and the slit-slot
is integrated with the end-rings
55 by die-casting, etc.
Since the shaft
55a made of the non-magnetic material, e.g.,
aluminum material, stainless material, etc. is integrated with the end-rings
55,
it is not necessary to provide the shaft
55a in the rotor iron core
3. Therefore, there is no shaft in the rotor iron core
3 illustrated
in FIG. 13, and the slit-slots
43 and
44 can be provided in a portion
in which the shaft is provided in the related art. Hence, the ratio between the
magnetic material and the non-magnetic material in the direction of the q-axis
can be set at a determined ratio (it is desired that the ratio of the magnetic
material and the ratio of the non-magnetic material are equal).
Specifically, the width of the slit-slots
4,
42,
43,
44, and
4e which are portions made of the non-magnetic material
and the width of the slit-slots (
4,
42,
43,
44, and
4e) of the rotor iron core
3 which are portions made of the
magnetic material in the direction of the q-axis can be set equal for obtaining
the determined ratio of 1:1. At this time, by setting the widths between the slit-slots
(
4,
42,
43,
44, and
4e) of the rotor
iron core
3 to prevent the deformation at a time of punching and maintain
the strength of the rotor, it is possible to maintain the reliability, and the
efficient synchronous inductance motor can be realized.
As stated, by using the non-magnetic material for the shaft
55a and
integrating the shaft
55a with the end-rings
55 by die-casting,
etc., it becomes unnecessary to provide the shaft
55a in the rotor
iron core
3, and the slit-slots (
43,
44) can be provided in
a portion where the shaft is provided in the related art. Hence, the ratio of the
magnetic material and the ratio of the non-magnetic material in the direction of
the q-axis, i.e., the difficult-to-pass direction of the magnetic flux, can be
set at the determined ratio, and the efficient motor can be realized. Further,
since it is not necessary to provide the shaft
55a in the rotor iron
core
3, the slit-slot (
43,
44) can be provided in the portion
where the shaft is provided in the related art. Hence, the width between the slit-slots
can be set flexibly to obtain the strength, and the reliable synchronous inductance
motor can be realized.
Embodiment 3
With reference to drawings, Embodiment 3 of this invention is explained. FIG.
14 illustrates manufacturing of the rotor of the synchronous inductance motor in
Embodiment 3 of this invention. In FIG. 14, for punching the electromagnetic steel
plate in a shape of the rotor by a die for punching which is a mechanism for punching,
when two or more slit-slots are adjacent, the slit-slots are punched a few times
so that adjacent slit-slots are not punched at once. Accordingly, the rotor iron
core is punched accurately. In this embodiment, the rotor iron core
3 in
the shape illustrated in FIG. 7 explained in Embodiment 1 is punched consecutively.
In FIG. 14, an electromagnetic steel plate
8 is put through the die for
punching (not illustrated) which is the mechanism for punching consecutively. FIG.
14 shows the rotor iron core
3 punched by the mechanism for punching consecutively.
In FIG. 14, slit-slots
8a,
8b,
8c, and
8f include the slit portions for generating reluctance torque and
the slot portions for generating inductance torque, and the slit-slots are placed
adjacently in a horizontal direction toward the direction of the d-axis. A through-hole
85 for a shaft and an outer circumference
83 of the rotor iron core
3 are illustrated.
As illustrated in FIG. 14, in [A], the through-hole
85 for the shaft is
punched by a mechanism for punching a through-hole for a shaft, and the slit-slot
8a which is closest to the outer circumference is punched by a mechanism
for punching a slit-slot which is closest to the outer circumference. In this operation,
the through-hole
85 for the shaft and the slit-slot
8a which
is closest to the outer circumference can be punched separately. However, time
for operation can be reduced by punching them at once.
In [B], among three adjacent slit-slots, i.e., slit-slots
8b,
8c,
and
8f, the slit-slot
8b and the slit-slot
8f
except the slit-slot
8c are punched together by a mechanism for
punching non-adjacent slit-slots so that the adjacent slit-slots are not punched
together. It is not necessary to punch the slit-slot
8b and the slit-slot
8f together. The slit-slot
8b and the slit-slot
8f
can be punched separately.
Then, in [C], the slit-slot
8c between the slit-slot
8b
and the slit-slot
8f, which is adjacent to the slit-slot
8b
and the slit-slot
8f is punched by the mechanism for punching
adjacent slit-slots. Then, in [D], the outer circumference
83 of the rotor
iron core
3 is punched by a mechanism for punching the outer circumference
of the rotor iron core, and the rotor iron core
3 is completed. Then, after
a plurality of rotor iron cores
3 is layered, a plurality of slit-slots
and end-rings provided at both ends of the rotor iron core layered are integrated
by die-casting the non-magnetic material, e.g., the aluminum material, and the
rotor
30 is completed.
For punching the rotor iron core
3, when a plurality of adjacent slit-slots
including a linear portion in the direction of the q-axis are adjacent (the slit-slots
8b,
8c, and
8f are adjacent in a horizontal
direction (direction of the d-axis), stress is concentrated in a narrow part of
the rotor iron core
3 (electromagnetic steel plate) between the slit-slots
in punching together. Hence, the strength weakens, and the accuracy in punching
the rotor iron core
3 drops. In this embodiment, the adjacent slit-slots
(the slit-slots
8b,
8c, and
8f are adjacent)
are not punched together. Since the slit-slot
8c between the slit-slot
8b and the slit-slot
8f, which is adjacent to the slit-slot
8b and the slit-slot
8f is punched after the slit-slot
8b and the slit-slot
8f are punched, the stress is
not concentrated in the narrow part between the slit-slots, which is created after
punching. Therefore, the accuracy in punching the rotor iron core
3 does
not drop, and the strength of the rotor iron core is maintained.
Specifically, when the rotor includes the plurality of slit-slots,
the narrow part between the slit-slots is created by punching the adjacent slit-slots
together. The stress is concentrated in the narrow part, and there is a possibility
that a sectional form of the slit portion is deformed and bent almost in a V shape.
When the rotor iron core
3 is layered while the sectional form of the narrow
part is deformed, a gap is created in an axial direction in the deformed portion
in layering.
When the slit-slot is filled with the aluminum material by die-casting the aluminum
in the state with the gap created, there is a possibility that the aluminum material
leaks from the gap in the axial direction to a portion between the rotor iron cores
3 layered, and a bridge is created. When the motor is operated using the
rotor to which the bridge is created, unnecessary current flows into the bridge,
and the characteristics as the inductance motor deteriorates. Therefore, there
is a possibility that the vibrations and the noise are caused by the torque during
asynchronous operation.
However, in this embodiment, when the rotor iron core is punched using a
mechanism for punching, i.e., the die for punching, the slit-slot is punched in
a few times so that the adjacent slit-slots are not punched together and the stress
is not concentrated in the narrow part between the adjacent slit-slots. Therefore,
it is possible to minimize the deformation of the sectional shape of the slit-slot.
Hence, even when the slit-slot is filled with the aluminum material by die-casting
aluminum, the aluminum material does not leak, and the bridge is not created. Accordingly,
the unnecessary current does not flow into the bridge, and the characteristics
as the inductance motor does not deteriorate. Further, it is possible to suppress
generation of the vibrations and the noise caused by the torque during asynchronous operation.
As stated, in this embodiment, the slit-slot
8b and the slit-slot
8f except the slit-slot
8c are punched together by
the mechanism for punching the non-adjacent slit-slots so that the adjacent slit-slots
are not punched together. After the slit-slot
8c between the slit-slot
8b and the slit-slot
8f, which is adjacent to the slit-slot
8b and the slit-slot
8f is punched by the mechanism
for punching the adjacent slit-slots. Therefore, the stress is not concentrated
in the narrow part of the electromagnetic steel plate, created in the direction
of the q-axis between the slit-slots in simple equipment. Hence, a reliable synchronous
inductance motor without deformation of the rotor iron core, etc. and an apparatus
for manufacturing the synchronous inductance motor can be realized.
Since the creation of the bridge can be suppressed, the unnecessary current
does not flow into the bridge, and the characteristics as the inductance motor
does not deteriorate. Further, since it is possible to suppress generation of the
vibrations and the noise caused by the torque during the asynchronous operation,
the efficient synchronous inductance motor with the low vibrations and low noise
and the apparatus for manufacturing the synchronous inductance motor can be realized.
Further, the reliable rotor of which rotor iron core is pun
