JP3821184B2 - Permanent magnet motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inner rotor type permanent magnet motor used for an air conditioner, a compressor of a refrigerator, and the like. More specifically, the core sheet itself has a balance weight and does not require a separate balance weight. It relates to an electric motor.
[0002]
[Prior art]
As a configuration of the inner rotor of this type of permanent magnet motor, for example, a configuration shown in FIG. 5 in which a permanent magnet is embedded in a rotor core has been proposed. As shown in FIG. 5, on the rotor core 2 in the 24-slot stator core 1, plate-like permanent magnets 3 are arranged in the circumferential direction along the outer diameter for the number of poles (four poles) of the permanent magnet motor. In addition, a flux barrier 4 is formed between the adjacent permanent magnets 3 to prevent a short circuit and leakage of magnetic flux. In addition, 5 is a center hole (hole for shafts).
[0003]
Here, assuming that the magnetic flux distribution in the gap (between the teeth of the stator core 1 and the permanent magnet 3) by the permanent magnet 3 is sinusoidal, the torque T of the permanent magnet motor is T = Pn {Φa · Ia Cos β-0.5 (Ld−Lq) · I ² · sin 2β} T is the output torque, Φa is the armature flux linkage by the permanent magnets on the d and q coordinate axes, Ld and Lq are d and q axis inductances, Ia is the amplitude of the armature current on the d and q coordinate axes, and β is The advance angle of the armature current on the d and q coordinate axes from the q axis, Pn, is the number of pole pairs.
[0004]
In the above equation, the first term is the magnet torque generated by the permanent magnet 3, and the second two terms are the reluctance torque generated by the difference between the d-axis inductance and the g-axis inductance. For details, see T.W. IEEE Japan, Vol. See 117-D, No. 7, 1997.
[0005]
By the way, as shown in FIG. 6, the compressor of an air conditioner or a refrigerator is mainly composed of a compression mechanism part A and an electric motor part (permanent magnet motor) B, and the refrigerant is compressed by the rotation of the permanent magnet motor. . In this case, since it is necessary to correct the regular load fluctuation (rotation imbalance) in the compression mechanism part A, a balance weight is attached to the motor part B side.
[0006]
For example, as shown in FIGS. 7 and 8, when the rotor core 2 is caulked with caulking pins 6, the deformed disc 7 of the balance weight is caulked simultaneously. In this way, by providing the rotor core 2 with a reverse balance with respect to the rotation imbalance in the compression mechanism section A, the rotation imbalance can be corrected.
[0007]
[Problems to be solved by the invention]
However, in the permanent magnet motor, in order to attach the deformed disc 7 of the balance weight, parts other than the motor parts are required, which results in an increase in cost and avoids an increase in cost due to an increase in manufacturing steps. Absent. Moreover, at the time of high rotation, the centrifugal force increases, and there is a risk that the deformed disc 8 of the balance weight falls off.
[0008]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to eliminate the need for a balance weight as a separate part by providing the balance weight function in the rotor core itself, and without increasing the cost due to manufacturing steps. It is an object of the present invention to provide a permanent magnet motor that can be used.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect of the present invention is the permanent magnet motor having a rotor core therein, wherein the rotor core has a slit for adjusting reluctance torque and generates only reluctance torque. a core, includes a second core coaxially to generate Ma Gunetto torque is embedded at equal intervals along the core periphery a pole number of the permanent magnets, the core sheet constituting the first core when cut a portion Taseru lifting the balance weight to the rotor core, it is characterized by cutting out a portion of the first core to include a slit for the reluctance torque generation.
[0010]
In this case, as described in claim 2, the first core is formed with holes for flux barriers facing both ends of the permanent magnet of the second core, and the reluctance adjustment is performed. It is preferable that the slit for use fits within the cross section of the permanent magnet.
[0011]
Further, as described in claim 3, the first core may be cut out at a plurality of locations, or a part of the core sheet may be cut out at a plurality of locations.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. In the figure, the same parts as those in FIG.
[0013]
If the permanent magnet electric motor of the present invention comprises an inner core by a core (first core) which does not have a permanent magnet and generates only reluctance torque, and a core (second core) which has a permanent magnet, The present invention focuses on the fact that the function of the balance weight can be exhibited by cutting out a part of the core sheet constituting the first core.
[0014]
Therefore, as shown in FIGS. 1 to 3, the rotor core 10 of the permanent magnet motor does not have a permanent magnet, and has a first core (iron core) having a hole 11 a for flux barrier and a slit 11 b for adjusting reluctance. ) 11 and a second core (iron core) 12 in which a fan-shaped permanent magnet 12a having a substantially sectional fan shape is embedded along the outer periphery of the core at equal intervals. 2 is a top view of the rotor core 10 shown in FIG . 1 (right side view of FIG. 1) , and FIG. 3 is a bottom view of the rotor core 10 (left side view of FIG. 1) .
[0015]
As shown in FIG. 2 and FIG. 4, the first core 11 is formed by cutting a part of the core to form a cut portion k, and the rotor core 10 has a balance weight. In this case, cutting portion k of the first core 11 preferably utilizes a slit 11b. That is, the cutout portion k includes the slit 11b.
[0016]
The flux barrier hole 11a is formed so as to face both end portions of the permanent magnet 12a, and is formed so as to be included in the cross section of the permanent magnet 12a. The slit 11b for reluctance adjustment aims at increasing the difference between the d-axis and the q- axis inductance, and is a reverse arc-shaped hole with the convex portion directed to the center hole (for shaft) 13 along the outer periphery of the core. It forms in a space | interval and forms so that it may be contained in the cross section of the permanent magnet 12a. As a result, the q-axis inductance Lq is large and the d-axis inductance Ld is small, that is, the difference in inductance (Lq−Ld) is large, and reluctance torque can be generated.
[0017]
The first core 11 and the second core 12 are integrally formed by an automatic laminating method, which will be described later, but a hole 11a for flux barrier and a slit 11b for adjusting reluctance are included in the hole of the permanent magnet 11a. To be. Reference numeral 14 denotes a rivet, and 15 denotes a caulking portion. The first core 11 is preferably within 20% of the rotor core 10, that is, within 20% of the laminated length (total laminated length) described later.
[0018]
By the way, in the manufacture of the rotor core 10, a core lamination method (first and second cores 11 and 12 are integrally formed by punching an electromagnetic steel sheet by automatic pressing using a core press die and caulking in the die ( Adopt automatic lamination method.
[0019]
In this pressing process, when punching out the first core 11, at least the hole corresponding to the permanent magnet 12 a of the second core 12 is not punched out, and the flux barrier hole 11 a and the reluctance adjustment slit 11 b are punched out, In order to attach the balance weight, a part including the slit 11b is cut out, and when the second core 12 is punched, the holes 11a, the slit 11 and the holes of the permanent magnet 12a are punched.
[0020]
Further, the hole for passing the caulking pin 14 is punched when the first and second cores 11 and 12 are pressed, and the caulking portion 15 is formed every time the core sheets 10a of the first and second cores 11 and 12 are laminated. . Therefore, it is possible to use the press processing by the conventional automatic lamination method as it is.
[0021]
Thus, after automatically pressing and caulking the laminated core, a ferrite magnet is embedded in the hole of the permanent magnet 12a and capped, the rotor core 10 is caulked through the caulking pin 14, and the permanent magnet 12a is magnetized. Magnetize. In addition, with reference to FIG. 4, three-phase (U-phase, V-phase, and W-phase) armature windings are applied to the 24-slot stator core 1. The lines may be different. In the stator core 1, for example, the outer diameter side winding may be the U phase, the inner diameter side winding may be the W phase, and the intermediate winding may be the V phase.
[0022]
In this way, since the first core 11 itself has a balance weight, it is not necessary to use new parts, that is, the balance weight of another part can be eliminated, and accordingly, the cost of the motor can be reduced. Can be planned.
[0023]
In addition, the first and second cores 11 and 12 can be manufactured by the conventional automatic lamination method, and the number of manufacturing steps of the rotor core 10 is reduced. Therefore, the cost of the motor can be further reduced. Furthermore, the problem of dropping off the balance weight does not occur, and the reliability can be improved.
[0024]
On the other hand, the reluctance torque is generated by the first core 11 and the magnet torque is generated by the second core 12, that is, it is possible to obtain a necessary motor torque, thereby suppressing a decrease in efficiency of the motor. Can do. Further, the fat Rashiresu DC motor incorporating a rotor core formed by the above, by using as a compressor motor or the like of the air conditioner, without up the cost, increase the performance up (operation efficiency of the air conditioner, the vibration And noise reduction).
[0025]
The size of the cut portion k of the first core 11 may be changed according to the balance weight required, and the number of core sheets may be changed. In addition, as for the location of the cut-out portion k, it is preferable to cut out a plurality of locations, even if it is a multiphase multipolar motor, even if it is not a single location. Therefore, an adaptive balance way can be attached according to the use situation of the motor.
[0026]
【The invention's effect】
As described above, according to the invention described in 請 Motomeko 1, in the permanent magnet motor having a rotor core therein, the rotor core, first to generate only reluctance torque has a slit for adjusting the reluctance torque a core, includes a second core coaxially to generate Ma Gunetto torque is embedded at equal intervals along the core periphery a pole number of the permanent magnets, the core sheet constituting the first core when cut a portion Taseru lifting the balance weight to the rotor core, by which is adapted cut a portion of the first core to include a slit for the reluctance torque generation, it is imparted the balance weight function in the rotor core itself This eliminates the need for separate balance weights, thus reducing motor costs. It is Ru can. In addition, since reluctance torque is generated even in the cut-out part, there is no influence on the generation of reluctance torque, and there is no increase in the cost of manufacturing the rotor core by the automatic lamination method. There is an effect that it is not necessary.
[0027]
According to the invention described in claim 2, the first cores in claim 1, to form a hole for flux barrier to be opposed to both end portions of the permanent magnets of said second core, before cut Rakutansu Since the adjustment slit is accommodated in the cross section of the permanent magnet, in addition to the effect of the first aspect, the flux barrier can prevent magnetic flux from being short-circuited and leaked, and the flux barrier hole and slit can be prevented. Is contained within the cross section of the permanent magnet, the conventional automatic lamination method of the rotor core can be used, that is, there is an effect that the manufacturing cost is not increased.
[0028]
According to the invention described in claim 3, a portion to cut the pre-Symbol first core and a plurality of locations, or by a plurality of core sheets to cut a portion, in addition to the effect of claim 1, in various weight There is a useful effect that a balance weight can be attached, that is, an adaptive balance weight can be provided.
[Brief description of the drawings]
[1] The present invention vertical sectional view real 施形 condition substantially specific to indicate to approximate the rotor core included in the permanent magnet motor according to.
2 is a schematic top view of a rotor core shown in FIG. 1 (right side view of FIG. 1).
3 is a schematic bottom view of the rotor core shown in FIG. 1 (left side view of FIG. 1).
Figure 4 is a schematic plan view of a permanent magnet motor having a rotor core shown in FIG.
Figure 5 is a schematic plan view showing a conventional permanent magnet motor.
Figure 6 is a schematic sectional view showing a compressor using a permanent magnet motor shown in FIG.
Figure 7 is a schematic side view showing a rotor core of a conventional permanent magnet motor.
8 is a top view of the rotor core shown in FIG. 7 (right side view of FIG. 7) .
[Explanation of symbols]
1 Stator Core 10 Rotor Core (Embedded Magnet Field Core)
11 First core 11a Hole (for flux barrier)
11b Slit (Reluctance adjustment hole)
12 First core 12a Permanent magnet 13 Center hole (for shaft)
14 Caulking pin 15 Caulking part k Cutting part

Claims (3)

In the permanent magnet motor having a rotor core therein, the rotor core has a first core that has a slit for adjusting reluctance torque and generates only reluctance torque, and permanent magnets corresponding to the number of poles are equally spaced along the outer periphery of the core. buried to a and the second core for generating Ma Gunetto torque contained coaxially, wherein when Taseru lifting the balance weight to the first of the rotor core cut and a portion of the core sheets constituting the core, the reluctance torque A part of the first core is cut out so as to include a slit for generation . Wherein the first core, and forming a second hole in to face the both end portions of the permanent magnets of the core flux barriers, fits the slit before cut Rakutansu for adjusting the cross section of the permanent magnet The permanent magnet motor according to claim 1, which is configured as described above. The permanent magnet motor according to claim 1, wherein the first core is cut out at a plurality of locations, or a plurality of core sheets are cut out at a part.

Images