WO2019073579A1

WO2019073579A1 - Permanent magnet motor, permanent magnet motor manufacturing method, and compressor

Info

Publication number: WO2019073579A1
Application number: PCT/JP2017/037028
Authority: WO
Inventors: 裕貴田村; 隆徳渡邉; 増本　浩二; 昇嗣朗堂本
Original assignee: 三菱電機株式会社
Priority date: 2017-10-12
Filing date: 2017-10-12
Publication date: 2019-04-18
Also published as: JPWO2019073579A1; JP6854910B2

Abstract

In this permanent magnet motor, the number S of slots formed on the stator and the number P of poles of the rotor satisfy the relationship of S > P. The rotor has a multistage skew structure in which rotor constituent bodies of respective stages arranged in the axial direction of a rotating shaft are disposed by being shifted in the circumferential direction. When θs is given by 360º/(the least common multiple of S and P) and θp_MAX is given by 360º/(2 x P), the skew angle θskew between the rotor constituent bodies at the highest and lowest stages satisfies the relationship of θs – (θp_MAX –θs) < θskew ≤ θs + (θp_MAX – θs). In addition, a method for manufacturing the permanent magnet motor forms a rivet insertion hole formed in a rotor core in an elongated hole shape along the circumferential direction about the rotational axis of the rotor and gives a skew to the rotor core after inserting a rivet into the rivet insertion hole.

Description

Permanent magnet type motor, method of manufacturing permanent magnet type motor and compressor

The present invention relates to a permanent magnet motor in which a permanent magnet is provided on a rotor, a method of manufacturing the permanent magnet motor, and a compressor including the permanent magnet motor.

Conventionally, a permanent magnet type motor comprising a rotor having a rotor core fixed to the outer periphery of a rotating shaft and a permanent magnet embedded in the rotor core, and a stator having a coil facing the permanent magnet is there. In this type of permanent magnet type motor, since a permanent magnet is used, a suction force works with the coil and a cogging torque is generated. In order to achieve smooth rotation with low noise and low vibration, it is effective to reduce the cogging torque, and a skew structure is well known as a method for reducing the cogging torque.

The skew structure is a structure in which the rotor is formed of a plurality of stages of rotor structures axially aligned, and the rotor structures of each stage are shifted in the circumferential direction and coupled. As a motor having a multistage skew structure of this type, there is, for example, Patent Document 1. In Patent Document 1, assuming that the skew angle θ in the circumferential direction of each stage is A, and the number of stages is N, then θ = 360 ° / (A × N) where A is the least common multiple of the number of slots and the number of poles. To reduce the cogging torque.

JP 2004-248422 A

When the rotor has a skew structure, harmonic components of the induced voltage that cause noise and vibration can be reduced, but in addition to harmonic components of the induced voltage, the fundamental wave component of the induced voltage also decreases. The induced voltage is greatly related to the performance of the motor, and the performance decreases as the induced voltage decreases. Therefore, it is necessary to set the skew angle in consideration of the decreasing rate of the induced voltage due to the skew structure. However, in Patent Document 1, the skew angle is set in consideration of only the reduction of the cogging torque. In an actual motor configuration, it is difficult to ignore the influence on performance due to the skew structure, and it is difficult to uniquely determine the skew angle as in the above equation taking into consideration only the reduction of the cogging torque.

In addition, in the method of manufacturing a rotor having a skew structure, breakage of a permanent magnet may occur in the permanent magnet when the rotor is skewed, and a manufacturing method that does not cause such a failure is required.

The present invention has been made in view of such a point, and a permanent magnet type motor capable of reducing the cogging torque and reducing the harmonic component of the induced voltage while suppressing the reduction of the induced voltage accompanying the skew, and manufacturing It is an object of the present invention to provide a manufacturing method and a compressor of a permanent magnet type motor capable of preventing damage to a permanent magnet of when.

A permanent magnet type motor according to the present invention includes a rotor having a plurality of permanent magnets constituting magnetic poles, a rotary shaft of the rotor, and a stator disposed on the outer peripheral side of the rotor, and is formed on the stator The number of slots S and the number of poles P of the rotor satisfy S> P, and in the rotor, the rotor structure of each stage aligned in the axial direction of the rotation axis is offset in the circumferential direction The skew angle θskew between the uppermost stage rotor structure and the lowermost stage rotor structure has a multistage skew structure disposed, and θs is 360 ° / (the least common multiple of S and P), θp_ _MAX the 360 ° / (2 × P) and the time, and satisfies a relationship _{θs- (θp_ MAX -θs) <θskew} ≦ θs + (θp_ MAX -θs).

A method of manufacturing a permanent magnet type motor according to the present invention includes a rotor core including a plurality of laminated magnetic steel sheets and a plurality of permanent magnets disposed on the rotor core and constituting magnetic poles. A manufacturing method of a permanent magnet type motor provided with a rotor having a skew structure in which a plurality of bodies are arranged axially in the axial direction and rotor constructions in the respective stages are shifted in the circumferential direction, and a plurality of electromagnetic steel plates are laminated. Process the process of forming the rotor core, the process of arranging the permanent magnet in the magnet insertion hole formed in the rotor core, and the rivet through the rivet insertion hole formed in the rotor core to make the skew of each stage Providing a step of forming the rotor structure of each step and a step of caulking and fastening with a rivet, and the rivet insertion hole has an elongated hole shape along the circumferential direction around the rotation axis of the rotor It is.

A compressor according to the present invention includes the above-described permanent magnet type motor, and a compression mechanism unit connected to the permanent magnet type motor via a rotary shaft and compressing a refrigerant by a driving force transmitted via the rotary shaft. Is provided.

According to the permanent magnet type motor and the compressor of the present invention, the cogging torque is reduced and the harmonic component of the induced voltage while suppressing the drop of the induced voltage accompanying the skew by setting the skew angle θskew within an appropriate range. Can be reduced.
Further, according to the manufacturing method of the present invention, both end portions in the axial direction are chamfered on each of the front end surface and the rear end surface in the circumferential direction of the permanent magnet. For this reason, when the rotor core moves in the circumferential direction, the chamfered portion of the permanent magnet contacts the rotor core of the adjacent step so that the permanent magnet moves in the axial direction in the magnet insertion hole and the circumferential direction moves. Since the rotor structure moves in the circumferential direction, it is possible to prevent the permanent magnet from being broken.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view of the airtight type scroll compressor provided with the permanent magnet type motor which concerns on Embodiment 1 of this invention. It is a schematic longitudinal cross-sectional view which shows the permanent-magnet type | mold motor which concerns on Embodiment 1 of this invention. It is a schematic plan view which shows the permanent magnet type motor which concerns on Embodiment 1 of this invention. It is a schematic longitudinal cross-sectional view which shows the rotor fixed to the rotating shaft of the compressor which concerns on Embodiment 1 of this invention. It is the figure which put together the schematic cross section of the rotor structure of each stage of FIG. It is a characteristic view showing change of a motor characteristic for every skew angle theta skew in a permanent magnet type motor concerning Embodiment 1 of the present invention. FIG. 10 is a characteristic diagram showing a change in motor characteristics when the number of stages N is increased to 2 and 3 at an arbitrary skew angle. It is the cross-sectional view which showed the positional relationship of the permanent magnet of each step | level and a rivet penetration hole, and the shape of a rivet penetration hole in the rotor of the permanent magnet type motor which concerns on Embodiment 2 of this invention. It is the cross-sectional view which showed the positional relationship of the permanent magnet of each stage and a rivet penetration hole, and the shape of a rivet penetration hole in the conventional skew rotor as a comparative example. FIG. 9 is a longitudinal cross-sectional view of the rotor before the skew angle is added in the enclosed scroll compressor according to Embodiment 2 of the present invention, which is a cross section taken along a line DD in FIG. FIG. 10 is a longitudinal cross-sectional view of a rotor before skew angle is applied in a conventional permanent magnet type motor, taken along a line DD in FIG. 9; It is a figure which shows the modification of the rivet penetration hole provided in the rotor core in the permanent-magnet type | mold motor which concerns on Embodiment 2 of this invention.

Hereinafter, a compressor provided with a permanent magnet type motor according to an embodiment of the present invention will be described based on the drawings. Here, as a compressor, a so-called vertical sealed scroll compressor will be described as an example.

Embodiment.
First Embodiment
FIG. 1 is a longitudinal sectional view of a hermetic scroll compressor provided with a permanent magnet motor according to a first embodiment of the present invention. In FIG. 1, hatching indicating a cross section is partially omitted. Hereinafter, the configuration of the enclosed scroll compressor 100 will be described with reference to FIG. The sealed scroll compressor 100 of FIG. 1 compresses and discharges a working gas such as a refrigerant, for example. The closed scroll compressor 100 includes a closed container 108 in which lubricating oil is stored at the bottom and which constitutes the outer shell of the closed scroll compressor 100. In the sealed container 108, a permanent magnet type motor 104 and a permanent magnet type motor 104 are connected via a rotary shaft 107, and a compression mechanism portion that compresses a refrigerant by a driving force transmitted via the rotary shaft 107. 101 and an oil pump 112 are accommodated.

The closed container 108 is formed, for example, in a cylindrical shape, and has pressure resistance. A suction pipe 109 for taking in the working gas into the sealed container 108 is connected to the side surface of the sealed container 108. Connected to the upper portion of the closed vessel 108 is a discharge pipe 110 that discharges the compressed working gas from the closed vessel 108 to the outside.

The compression mechanism portion 101 compresses the fluid drawn into the closed container 108 from the suction pipe 109, and includes a swing scroll 103 and a fixed scroll 102. A compression chamber is formed between the spiral portion of the oscillating scroll 103 and the spiral portion of the fixed scroll 102, and the fluid is compressed in the compression chamber. A refrigerant or air is used as the fluid. As the refrigerant, for example, a single refrigerant consisting of HFO-1123 or a mixed refrigerant containing HFO-1123 is used.

The permanent magnet type motor 104 rotationally drives the rotating shaft 107 and has a stator 105 and a rotor 106 to generate a rotational force. The rotor 106 is fixed to the rotating shaft 107 by shrink fitting or the like, and the stator 105 is fixed to the closed container 108 by shrink fitting or the like. A lead wire 113 is connected to the stator 105, and the lead wire 113 is connected to a sealing terminal 111 provided on the hermetic container 108 in order to receive power supply from the outside of the hermetic container 108. When power is supplied to the stator 105, the rotating shaft 107 and the rotor 106 rotate with respect to the stator 105.

An oil supply passage 107 a extending in the axial direction of the rotary shaft 107 is formed inside the rotary shaft 107, and an oil pump 112 is connected to the lower end of the rotary shaft 107. The oil pump 112 sucks the lubricating oil stored at the bottom of the closed container 108 and supplies it to the oil supply passage 107 a in the rotating shaft 107. The oil supplied to the oil supply passage 107 a is supplied to each sliding portion of the compression mechanism section 101.

An eccentric shaft portion is installed at the upper end of the rotating shaft 107, and is engaged with a swing bearing formed in a boss portion of the swing scroll 103.

Hereinafter, the permanent magnet type motor 104 will be described in detail with reference to FIGS. 2 and 3.

FIG. 2 is a schematic vertical sectional view showing the permanent magnet type motor according to the first embodiment of the present invention. FIG. 3 is a schematic plan view showing a permanent magnet type motor according to Embodiment 1 of the present invention.
In the permanent magnet type motor 104, the rotor 106 is disposed inside the stator 105, and is an annular rotor formed by axially laminating a plurality of electromagnetic steel plates made of a high magnetic permeability material such as iron. It has a core 31. In the rotor core 31, magnet insertion holes 32 equal in number to the magnetic poles are formed at intervals in the circumferential direction, and flat permanent magnets 33 constituting the magnetic poles are embedded in each of the magnet insertion holes 32. ing. The permanent magnet 33 is made of, for example, a neodymium magnet or a rare earth magnet.

The rotor 106 also has end plates 34 made of nonmagnetic material on both sides in the axial direction of the rotor core 31. The end plate z34 and the rotor core 31 are formed with a rivet insertion hole 37 penetrating both in the axial direction, and the rivet 36 is inserted into the rivet insertion hole 37 and the whole is fastened in the axial direction. A balance weight 35 is disposed at one end of the rotor core 31 in the axial direction and outside the end plate 34, and the balance weight 35 is crimped by rivets 36 together with the end plate 34 and the rotor core 31. ing. Although FIG. 2 shows an example in which the balance weight 35 is arranged at one end of the rotor core 31 in the axial direction, it may be arranged at both ends.

The stator 105 includes a plurality of teeth 41 formed in the stator core 105a and a plurality of slots 42 formed between the teeth 41, and a conductor wire is wound in a concentrated winding around each of the plurality of teeth 41 to form a coil. 43 has a formed structure.

The permanent magnet type motor 104 according to the first embodiment is a concentrated winding motor in which the number of slots S of the stator 105 and the number of poles P of the rotor 106 satisfy the relationship of S> P. It consists of a DC motor.

FIG. 4 is a schematic vertical cross-sectional view showing the rotor fixed to the rotary shaft of the compressor according to Embodiment 1 of the present invention. FIG. 5: is the figure which put together the schematic cross section of the rotor structure of each step | stage of FIG. In FIG. 5, (a) is an AA cross section of FIG. 4, (b) is a BB cross section of FIG. 4, and (c) is a CC cross section of FIG. Further, in FIG. 5, components other than the rotor core 31 and the permanent magnet 33 are not shown for the sake of easy understanding.

The rotor 106 has a three-stage skew structure in which three rotor structures 106a, a rotor structure 106b and a rotor structure 106c are axially aligned. The rotor structure 106a includes a rotor core 31a and a permanent magnet 33a. The rotor structure 106b includes a rotor core 31b and a permanent magnet 33b. The rotor structure 106c includes a rotor core 31c and a permanent magnet 33c.

The rotor structure 106a, the rotor structure 106b, and the rotor structure 106c are disposed at positions mutually offset in the rotational angle direction. This angle is called skew angle θ. The position of the rotor structure 106a is referred to as 0 °, the skew angle θ of the rotor structure 106b is referred to as a skew angle θ1, and the skew angle θ of the rotor structure 106c is referred to as a skew angle θ2. Further, the skew angle of the entire rotor between the uppermost stage rotor structure 106a and the lowermost rotor structure 106c is referred to as a skew angle θ skew. FIGS. 4 and 5 show a configuration example in which the skew angle θ1 of the rotor structure 106b is 10 °, the skew angle θ2 of the rotor structure 106c is 20 °, and the skew angle θskew is 20 °.

Then, as a feature of the first embodiment, the range of the skew angle θskew capable of reducing the cogging torque and reducing the harmonic component of the induced voltage while suppressing the reduction of the induced voltage accompanying the skew is the following (1) It is in the definition of the scope.

_{θs- (θp_ MAX -θs) <θskew} ≦ θs + (θp_ MAX -θs)
... (1)
here,
θs: 360 ° / (the least common multiple of S and P)
_{θp_ MAX: 360 ° / (2} × P)

Further, each rotor structure has the same design and the same axial length, and each skew angle θ between the rotor structures adjacent to the upper and lower sides has the following formula (2) when the number of stages is N: Is represented by
θ = θ skew / (N-1) (2)

Although the skew angle θ is the angle obtained by the equation (2), the range of the error is included.

Next, the ground for setting the skew angle θ skew in the range of the above (1) will be described. Here, the basis of the three-stage skew structure shown in FIG. 4 will be described as an example. The number of stages of the skew structure is not limited to three, and may be a multistage skew structure in which a plurality of three or more stages are arranged.

The range of the skew angle θskew is set in consideration of the motor characteristics which change according to the skew angle θskew. Motor characteristics include cogging torque, harmonic components of induced voltage and induced voltage.

Here, as an example of the permanent magnet motor 104, a permanent magnet motor 104 in which the number of slots S of the stator 105 is 9 and the number of poles of the rotor 106 is 6 is used. The variation of the motor characteristics according to the skew angle θ skew will be described with reference to FIG. 6 by taking the 6-pole 9-slot concentrated winding permanent magnet type motor 104 as an example.

FIG. 6 is a characteristic diagram showing changes in motor characteristics for each skew angle θ skew in the permanent magnet type motor according to Embodiment 1 of the present invention. In FIG. 6, the horizontal axis indicates the skew angle θ skew. The vertical axis represents the change rate of each motor characteristic when the skew angle θ skew is increased with the motor characteristic at the skew angle θ skew of 0 ° as 100% of the reference. Here, the number of skew stages is three, which is the case of a concentrated winding motor with 6 poles and 9 slots. In FIG. 6, (a) cogging torque, (b) high frequency component of induced voltage and (c) induced voltage are shown as each motor characteristic. In addition, in FIG. 6, the cogging torque at the time of 2 steps | paragraphs, the high frequency component of induced voltage, and the change rate of induced voltage are also shown for comparison.

In the configuration of six poles and nine slots, as shown in FIG. 6A, the cogging torque starts to decrease and increase near the skew angle of 30 °. The following can be considered as the reason. That is, because of the configuration of six poles, the permanent magnets 33 embedded in the rotor 106 are arranged at a pitch of 60 ° in the circumferential direction. For this reason, in the case where a skew angle θ skew of more than 30 ° which is half thereof is given, it overlaps with the permanent magnet 33 of the opposite pole disposed next to it in the circumferential direction by more than half. Therefore, it is considered that the effect of reducing the cogging torque is lost and only the induced voltage is reduced. Therefore, it is preferable to set the skew angle θskew so that the range in which the permanent magnet 33 of the opposite pole arranged in the circumferential direction overlaps in the circumferential direction is not more than half the arrangement pitch of the permanent magnets 33 in the circumferential direction. .

From the above, it is preferable to set the skew angle θ skew to “360 ° / (2 × P)” or less in order to reduce the cogging torque and improve the vibration and noise without reducing the induced voltage related to the motor performance. It is. Among the skew angles θskew, “skew angle θskew for reducing cogging torque to improve vibration and noise” is hereinafter referred to as “skew angle θp”. Skew angle θp is, since "360 ° / (2 × P)" is preferably at most, in other words, the preferred maximum value Shitapi_ _MAX of the skew angle θp is "360 ° / (2 × P)". Here, since the number P = 6 pole, comprising skew angle Shitapi_ _MAX 30゜Ga 30 °.

Also, the harmonic component of the induced voltage has a downward convex characteristic as shown in FIG. 6 (b), and has the characteristic with the inflection point of the characteristic as the optimum value. Then, the skew angle of around 20 ° is the optimum value. Therefore, when the skew angle θ skew is set to about 20 °, harmonic components of the induced voltage can be reduced, which is effective in reducing vibration and noise. By the way, “360 ° / (the least common multiple of S and P)” is conventionally used as the optimal value of the skew angle for the purpose of reducing the cogging torque. Here, the number of slots S is 9, the number of poles P is 6, the least common multiple of S and P is 18, and the optimum value is 20 °. For this reason, in order to improve the vibration and noise due to the harmonic component of the induced voltage, it is preferable to set the skew angle θ skew to “360 ° / (the least common multiple of S and P)”. The “skew angle θ skew for improving the vibration and noise due to the harmonic component of the induced voltage” in the skew angle θ skew is hereinafter referred to as “skew angle θs”.

Therefore, by setting the skew angle θskew in a range where the skew angle θp and the skew angle θs overlap, it is possible to reduce cogging torque and harmonic components of the induced voltage without unnecessarily reducing the induced voltage. It becomes possible.

Here, since the harmonic component of the induced voltage has a downward convex characteristic as described above, it is possible to reduce the harmonic component of the induced voltage in a range having a width centered on the skew angle θs. . Here, the permanent magnet type motor 104 of the first embodiment since it satisfies the relationship of S> P, a skew angle θp_ _MAX> skew angle [theta] s. Therefore, when setting the range around the skew angle [theta] s, the maximum value side, the difference between Shitapi_ _MAX and [theta] s, using a value obtained by adding to a central [theta] s to "θs + (θp_ _MAX -θs)" It can be set. On the other hand, the minimum value side, and, among the range with a skew angle [theta] s = 20゜Wo center, the minimum value side, Shitapi_ _MAX and the difference between [theta] s, and subtracted from the [theta] s at the heart "θs- (θp_ _MAX -Θs) can be set.

To summarize the above, the range of the skew angle θ skew which can reduce the cogging torque and the harmonic components of the induced voltage without unnecessarily reducing the induced voltage is the range of the above (1). In the example of six poles and nine slots, [theta] s = 20 °, since it is θp_ _MAX = 30 °,
20 °-(30 ° -20 °) <θ skew ≦ 20 ° + (30 ° -20 °)
And
10 ° <θ skew ≦ 30 °.

Therefore, by setting the skew angle θ1 = 10 ° and the skew angle θ2 = 20 ° in FIG. 5, the three-stage skew can reduce the cogging torque and the harmonic components of the induced voltage without unnecessarily reducing the induced voltage. A permanent magnet type motor 104 of a structure can be obtained.

In setting the range of the skew angle θskew, the range is given with a width centered on “360 ° / (the least common multiple of S and P)” which is the optimum value of the skew angle θs, as described above. The range of (3) may be used.
360 ° / (the least common multiple of the S and P) <θskew ≦ θs + ( θp_ MAX -θs)
... (3)

That is, the lower limit side of the range of the skew angle θskew may not have a width, and “360 ° / (the least common multiple of S and P)” itself which is the optimum value of the skew angle θs may be set as the lower limit. The range of (3) is 20 ° <θ skew ≦ 30 ° in the example of 6 poles and 9 slots.

Next, the number of axial stages of the rotor 106, that is, the number of effective stages of skew will be described.

FIG. 7 is a characteristic diagram showing a change in motor characteristics when the number of stages N is increased to 2 and 3 at an arbitrary skew angle. In FIG. 7, the horizontal axis is the number of skew stages. The vertical axis represents a change rate of each motor characteristic when the number of skew stages is increased with the number of skew stages being one as 100% of the reference. In FIG. 7, as each motor characteristic, (a) cogging torque, (b) high frequency component of induced voltage, and (c) induced voltage are shown.

As shown in FIG. 7, it can be seen that the cogging torque reduction effect is obtained most when the stage number N = 2, and the cogging torque is increased by increasing the stage number N thereafter, and the cogging torque reduction effect is decreased. Conversely, it can be seen that the harmonic component of the induced voltage slightly increases with the number of stages 2, and thereafter the reduction effect increases. In addition, it can be seen that the induced voltage is substantially halved in the case of the stage number 1 in the case of the stage number 2, and the decrease can be suppressed as the stage number N is increased.

From the above, it is possible that N ≧ 3 as the number of stages N for obtaining the reduction effect of the cogging torque and the harmonic component of the induced voltage while suppressing the reduction of the induced voltage deeply related to the motor performance. Is desirable.

As described above, according to the first embodiment, by setting the skew angle skew in the range of the above (1), the cogging torque is reduced and the harmonics of the induced voltage are suppressed while the decrease in the induced voltage is suppressed. The component reduction effect can be obtained.

Second Embodiment
The second embodiment relates to a method of manufacturing a rotor having a skew structure.

FIG. 8 is a cross-sectional view showing the positional relationship between the permanent magnet of each step and the rivet insertion hole and the shape of the rivet insertion hole in the rotor of the permanent magnet type motor according to Embodiment 2 of the present invention . FIG. 9 is a cross-sectional view showing the positional relationship between the permanent magnet of each step and the rivet insertion hole and the shape of the rivet insertion hole in a conventional skew rotor as a comparative example.

Hereinafter, the shape and arrangement of the rivet insertion holes 37 suitable for forming and manufacturing a rotor having a skew structure will be described while comparing FIGS. 8 and 9. FIGS. 8 and 9 show a configuration example in which four rivets are used for fastening.
In the case of the multistage skew rotor of the comparative example shown in FIG. 9, the position of the rivet insertion hole 370 into which the rivet 360 is inserted in each of the

rotor cores

310a, 310b and 310c of each stage constituting the rotor core 310. Are the positions shown at

positions

370a, 370b and 370c. That is, the positions of the rivet insertion holes 370 in the respective stages differ from each other in the positional relationship with the permanent magnet 33, and hence the shapes of the rotor cores in the respective stages are different for each stage. Therefore, in the multistage skew rotor of the comparative example, it is necessary to prepare rotor cores for the number N of stages having different shapes. As a result, in order to punch a plurality of core shapes having different positions of the rivet insertion holes 370, core press molds having the same number as the number N of stages or core press molds having a control mechanism capable of selectively pressing a plurality of types must be prepared. It led to cost increase.

In the second embodiment, as shown in FIG. 8, the rivet insertion hole 37 has an elongated hole shape along the circumferential direction around the rotation axis 107. Furthermore, the circle of the same diameter as the rivet 36 is slightly larger than the outer shape of the locus formed by moving in the circumferential direction about the rotation axis 107. By making the rivet insertion hole 37 into the above-mentioned elongated hole shape, it is not necessary to make the rotor core 31 into individual shapes in each step, and it is possible to make one common shape. The reason will be described later.

In the second embodiment, the angular width θr of the rivet insertion hole 37 is in the range of (4) below. Note that FIG. 9 shows the case where the skew angle θs = 20 ° mentioned in the first embodiment and the angle width θr of the rivet insertion hole 37 have the same value.
_{θskew ≦ θr ≦ θp_ MAX = 360} ° / (2 × P) ··· (4)

When fixing the rotor 106 to the rotating shaft 107, radial displacement of the rotor core 31 with respect to the rotating shaft 107 becomes a problem. However, by setting the rivet insertion holes 37 to have a small radial movement width as described above, it is possible to move the rotor 106 in the circumferential direction and suppress any skew while suppressing radial deviation of the rotor core 31. It becomes possible to set to the corner.

Next, a method of assembling the rotor 106 will be described.
First, a plurality of electromagnetic steel plates are stacked to form the rotor core 31. Then, the permanent magnet 33 is disposed in the magnet insertion hole 32 of the rotor core 31. Next, the rivets 36 are passed through the rivet insertion holes 37 of the rotor core 31. Thereafter, in the rotor core 31, an arbitrary thickness is shifted in the circumferential direction by the skew angle θ. Here, when forming the rotor core 31 by laminating a plurality of electromagnetic steel plates, any desired laminated thickness which is finally distinguished as the rotor core 31a, the rotor core 31b and the rotor core 31c In each case, it is desirable to integrate in the axial direction by V caulking or the like. Then, the rotor cores of the respective stages integrated respectively may be stacked.

Next, the laminated rotor cores 31a, the rotor cores 31b and the rotor cores 31c are shifted in the circumferential direction by the skew angle θ obtained respectively. Here, as a method of shifting by the skew angle θ, the rotor cores 31 of the other stages may be moved in the circumferential direction with reference to the rotor core 31 of one of the stages.

Here, the middle stage rotor core 31 b and the lower stage rotor core 31 c are moved in the circumferential direction based on the upper stage rotor core 31 a. In this case, with the position of the upper stage rotor core 31a fixed, the middle stage rotor core 31b is moved in the circumferential direction together with the permanent magnet 33b. At this time, the rivet insertion hole 37 has the above-described elongated hole shape, and by the rivet 36 sliding in the rivet insertion hole 37, the rotor core 31b can be moved. Similarly, the lower rotor core 31c is moved in the circumferential direction together with the permanent magnet 33c.

In applying the skew angle θ to each rotor core, the outer diameter portion is gripped for each rotor core 31 of each stage, and the rotor cores 31 of the other stages are referenced based on the rotor core 31 of one of the stages. Can be moved in the circumferential direction, which can be realized by a relatively simple device.

After skewing is applied to each of the rotor core 31 b and the rotor core 31 c as described above, the rivet 36 is crimped to form the rotor 106 having a skew structure.

Here, the axial fastening force of the rivet 36 alone is weak against the rotational force applied to the rotor core 31 during operation, and is not sufficient to maintain the skew angle θ. However, with respect to the force in the rotational direction applied to the rotor core 31, the holding of the skew angle θ is established by the fixing force by the gap fitting and the shrink fitting when fixing the rotor 106 to the rotating shaft 107. Therefore, the fastening force with the rivet 36 is only required to maintain the strength sufficient to hold the skew angle θ until the rotor 106 is fixed to the rotating shaft 107. There is no need to improve the fastening power of 36.

Although the rivets 36 may be caulked and fastened after skewing as described above, the rivets 36 are caulked and fastened using caustic fastening force in the axial direction of the rivets 36 and then skewed. Thus, the rotor 106 having a skew structure may be formed.

Furthermore, although it is limited to the case where the permanent magnet 33 disposed in the rotor core 31 does not have a magnetic force, that is, so-called unmagnetized magnetization, it may be performed as follows. That is, after the rivets 36 are crimped, so-called magnetization may be performed by applying a magnetic force to the permanent magnets 33 disposed in the rotor core 31 with a magnetization yoke or the like, and then skewing may be performed. By doing this, it is possible to easily achieve the magnetization of the skew rotor and the arrangement of the permanent magnet 33 in the magnet insertion hole 32.

In the above assembling method, the following effects can be obtained by setting the laminated thickness of the rotor core 31a, the rotor core 31b and the rotor core 31c of each stage to the same thickness. That is, there is no need to worry about the stacking order at the time of assembly, and erroneous assembly can be prevented. Further, since all the permanent magnets 33 embedded in the rotor core 31 of each stage can be formed into the same shape, cost merits can be obtained by sharing the parts, and also in terms of reduction of management costs of different parts. You can get the benefits.

Next, an example will be given as to problems and solutions assumed in the process of circumferentially shifting the rotor core 31b and the rotor core 31c of each stage by the skew angle θ1 and the skew angle θ2 respectively required. deep.

FIG. 10 is a longitudinal cross-sectional view of a rotor before forming a skew angle in a hermetic scroll compressor according to a second embodiment of the present invention, and is a DD cross section of FIG. FIG. 11 is a longitudinal cross-sectional view of the rotor of the conventional permanent magnet type motor before the skew angle is given, which is a DD cross section of FIG.

At the time of rivet setting, the rotor core 31 contracts in the axial direction. For this reason, the permanent magnet 33 embedded in the rotor core 31 may be compressed in the axial direction to generate a crack or chip. Concerned about this, conventionally, as shown in FIG. 11, the axial dimension h1 of the state in which the permanent magnets 33 are stacked for the number of steps is the axial dimension of the rotor core 31 (hereinafter referred to as the laminated thickness) A configuration is known in which the length is set shorter than h2. In this configuration, the lower end portion of the permanent magnet 33a of the upper rotor core 31a is inserted into the middle rotor core 31b. In addition, the lower end portion of the permanent magnet 33b of the middle stage rotor core 31b enters the lower stage rotor core 31c. As described above, a part of each permanent magnet 33 enters the rotor core 31 different from the rotor core 31 to be originally inserted. When skewing is performed in such a state, the permanent magnet 33 is pressed in the circumferential direction in the rotor core 31, and there is a problem that a crack or chipping occurs.

Specifically, for example, when the rotor core 31b is shifted at the skew angle θ, a crack or chipping may occur in the permanent magnet 33a in the area D and a crack or chipping may occur in the permanent magnet 33b in the area E.

On the other hand, in the second embodiment, a manufacturing method for preventing such damage to the permanent magnet 33 will be described below.

In the second embodiment, as shown in FIG. 10, by providing a chamfer 50 at the outer peripheral edge of the permanent magnet 33, it is possible to easily prevent the permanent magnet 33 from coming in contact with the rotor core 31.

Here, a case is considered in which the middle stage rotor structure 106b is moved in the circumferential direction as indicated by the arrows in FIG. When the rotor core 31b of the middle stage rotor structure 106b moves in the circumferential direction, the chamfered 50 portion of the middle stage permanent magnet 33b contacts the lower stage rotor core 31c so that the permanent magnet 33b is in the magnet insertion hole 32. Is pushed upward in the axial direction. As the permanent magnet 33b is pushed upward in the axial direction, the permanent magnet 33a is also pushed up. As a result, the permanent magnet 33b is positioned in the rotor core 31b, and the permanent magnet 33a is positioned in the rotor core 31a. As a result, the rotor construction 106b can be moved in the circumferential direction to give a skew angle θ without causing damage to the permanent magnet 33a and the permanent magnet 33b in the area D and the area E.

Here, among the outer peripheral edge portions of the respective permanent magnets 33, the portion to be chamfered 50 may be at least the following position. That is, in each of the permanent magnets 33, it may be provided at both axial end portions of the front end surface 51 and the rear end surface 52 in the moving direction.

The chamfering dimension C may be set, for example, as follows. It is assumed that the number of stages is N and the axial dimensional difference between the rotor core 31 of each stage and the permanent magnet 33 of each stage is Δ (see FIG. 10). At this time, the axial dimension in which the uppermost stage permanent magnet 33a enters the rotor core 31b immediately below it is N / (N-1) × Δ. Therefore, the chamfering dimension C may be set to CCN / (N−1) × Δ. The chamfering shape may be a corner or a circle as long as the chamfering dimension C secures the above-mentioned range of dimensions.

As described above, according to the second embodiment, by setting the rivet insertion holes 37 as elongated holes extending in the circumferential direction, the rivet insertion holes can be provided at individual positions adjusted to an arbitrary skew angle θ for each step. The need to provide 37 can be eliminated. Therefore, the core shape required for the skew structure can be made common to each step, and a plurality of dies or a complicated press die capable of punching a plurality of core shapes can be dispensed with, and the cost of the press can be suppressed. The effect is obtained.

The shape of the rivet insertion hole 37 is not limited to the shape shown in FIG. 8, and may be the shape shown in FIG.

FIG. 12 is a view showing a modification of the rivet insertion hole provided in the rotor core in the permanent magnet type motor according to Embodiment 2 of the present invention.
The rivet insertion hole 37 in FIG. 12 has a shape obtained by smoothly connecting the outer shape of the shape obtained by shifting a circle having the same diameter as the rivet 36 in the circumferential direction by skew angle θ of the rotor structure of each stage. Have. Thus, the rivet insertion hole 37 functions as a positioning hole by forming the rivet insertion hole 37 into a shape having a contour of three circles in this case, and the rotor core 31 of each stage is accurately measured by the skew angle. It can be shifted.

In addition, when the rivet insertion hole 37 has the above-mentioned long hole shape, when the rivet 36 is passed through the rotor core 31, the outline portion of each circle in the rivet insertion hole 37 is shifted by a predetermined skew angle θ It is possible to carry out the lamination in As a result, it is possible to eliminate the need for a device for shifting the rotor core 31 by the skew angle θ after the lamination, which is necessary when forming an elongated hole without a circular outline.

Further, in the above-described first to second embodiments, the configuration of the hexagonal flat plate arrangement in which the flat permanent magnets 33 are installed at six places of the rotor 106 is selected from the ease of description. It is not limited to this installation. In addition, for example, the arrangement configuration of the magnets in the rotor 106 may be appropriately determined, such as an eight-sided flat plate arrangement or a four-way bathtub arrangement, according to the number of magnetic poles. The same applies to the stator 105, and the number of slots and the like may be appropriately determined according to the number of magnetic poles. However, in any of these arrangements, the optimum range of the skew angle θ provided by the present invention can be applied.

The effect obtained by the skew naturally differs depending on the circumferential distance between the permanent magnets 33 embedded in the rotor 106 or the radial position of the permanent magnets 33. For this reason, it goes without saying that it is necessary to set the skew angle θskew within the optimum range of the skew angle θskew provided in the present invention in consideration of the following. That is, it is set in consideration of an allowable performance reduction including the number of stages and an improvement rate of vibration and noise required for the device on which the permanent magnet type motor 104 is mounted. For acceptable performance degradation, the reduction in induced voltage may be confirmed by analysis or actual machine verification. Further, with regard to the rate of improvement of vibration and noise, each rate of reduction of the cogging torque and the harmonic component of the induced voltage may be confirmed by analysis or actual machine verification. Then, an appropriate skew angle θ skew may be derived using these confirmation results.

In the above-described first to second embodiments, the number of stator slots is S = 9, the number of rotor poles is P = 6, and the configuration is S: P = 3: 2, but the present invention is limited thereto. is not. It is sufficient that the relationship of S> P is satisfied, for example, a configuration other than S: P = 3: 2, such as S = 12, P = 10, may be used.

In the first to second embodiments described above, the configuration in which four rivets 36 are fastened is illustrated and described. However, the present invention is not limited to this. The rivets 36 may be configured as two, three, or five or more.

In the second embodiment described above, although the manufacturing method has been described using a diagram without the balance weight 35, the present invention is not limited to this. When the balance weight 35 is configured to be fastened together with the rotor core and the end plate 34 by the rivets 36, the rivet insertion holes 37 of the balance weight 35 may be formed in the same elongated shape. The rivet insertion holes 37 of the end plate 34 and the balance weight 35 may be as follows, on the assumption that the bearing surface is a contact area that can ensure the axial fastening force with the rivet 36. That is, the end plate 34 and the rivet insertion hole 37 of the balance weight 35 may be a long hole larger than the rivet insertion hole 37 of the rotor core 31 or a round hole in which the entire long hole of the rotor core 31 is accommodated. Further, only one of the balance weight 35 and the end plate 34 may have the above configuration.

In the first to second embodiments described above, the present invention has been described by way of example of the closed scroll compressor provided with the scroll type compression mechanism, but the closed magnet type motor according to the present invention is used for sealing The compression mechanism part of the mold compressor is not limited to the scroll type. Besides, the permanent magnet type motor of the present invention may of course be mounted on a hermetic type compressor using various compression mechanism parts, such as a rotary type, a vane type or a screw type.

Moreover, the compressor provided with the permanent magnet type motor of the present invention is particularly applicable to the compression of an air conditioner, a refrigerator, a freezer and the like.

Reference Signs List 31 rotor core, 31a rotor core, 31b rotor core, 31c rotor core, 32 magnet insertion holes, 33 permanent magnets, 33a permanent magnets, 33b permanent magnets, 33c permanent magnets, 34 end plates, 35 balance weights, 36 Rivets, 37 rivet insertion holes, 41 teeth, 42 slots, 43 coils, 50 chamfers, 51 end faces, 52 rear end faces, 100 sealed scroll compressors, 101 compression mechanism parts, 102 fixed scrolls, 103 oscillating scrolls, 104 permanent Magnet type motor, 105 stator, 105a stator core, 106 rotor, 106a rotor structure, 106b rotor structure, 106c rotor structure, 107 rotation shaft, 107a oil supply passage, 108 sealed container, 109 suction pipe , 110 discharge distribution , 111 sealed terminal, 112 an oil pump, 113 lead, 310 rotor core, 310a rotor core, 310b rotor core, 360 rivets, 370 rivet insertion hole.

Claims

A rotor having a plurality of permanent magnets constituting a magnetic pole;
The rotational axis of the rotor,
A stator disposed on an outer peripheral side of the rotor;
The number S of slots formed in the stator and the number P of poles of the rotor satisfy S> P,
The rotor has a multistage skew structure in which rotor structures of respective stages aligned in the axial direction of the rotation axis are offset in a circumferential direction, and the uppermost stage rotor structure and the lowermost stage skew angle θskew between the rotor structure is, (least common multiple of the S and P) 360 ° / a [theta] s, when the Shitapi_ MAX of 360 ° / (2 × P) ,
θs- (θp_ MAX -θs) <θskew ≦ θs + (θp_ MAX -θs)
A permanent magnet type motor that satisfies the relationship of
The skew angle θ skew is
360 ° / (the least common multiple of the S and P) <θskew ≦ θs + ( θp_ MAX -θs)
The permanent magnet type motor according to claim 1, which satisfies the following relationship:
The permanent magnet type motor according to claim 1 or 2, wherein a skew angle θ of the rotor structure of each of the stages is θ = θskew / (N-1), where N is the number of stages.
The permanent magnet motor according to any one of claims 1 to 3, wherein the number of stages of each stage is three or more.
The permanent magnet type motor according to any one of claims 1 to 4, wherein respective axial thicknesses of the rotor constructions of the respective stages are the same.
The rivet further includes a rivet inserted through a rivet insertion hole formed in the rotor and axially fastening the rotor.
The permanent magnet type motor according to any one of claims 1 to 5, wherein the rivet insertion hole has an elongated hole shape along a circumferential direction around a rotation axis of the rotor.
The permanent magnet motor according to any one of claims 1 to 6, wherein the permanent magnet is a neodymium magnet.
The permanent magnet type motor according to any one of claims 1 to 7, wherein the stator includes a coil configured by winding a conductor wire in a concentrated winding.
A rotor structure including a rotor core in which a plurality of electromagnetic steel sheets are stacked and a plurality of permanent magnets disposed on the rotor core and constituting a magnetic pole is axially aligned in a plurality of stages, and the rotation of each stage A manufacturing method of a permanent magnet type motor provided with a rotor of a skew structure in which a child structure is disposed circumferentially offset,
Laminating the plurality of electromagnetic steel sheets to form the rotor core;
Placing the permanent magnet in a magnet insertion hole formed in the rotor core;
Passing a rivet through the rivet insertion hole formed in the rotor core, and skewing the steps to form the rotor structure of each step;
And a process of caulking and fastening with the rivets,
Skew angle θskew between the rotor structure and the bottom of the rotor structure of the uppermost stage, (least common multiple of the S and P) 360 ° / the θs, θp_ MAX to 360 ° / (2 × When P),
θs- (θp_ MAX -θs) <θskew ≦ θs + (θp_ MAX -θs)
A method of manufacturing a permanent magnet type motor satisfying the relationship of
10. The method for manufacturing a permanent magnet type motor according to claim 9, wherein the rivet insertion hole has an elongated hole shape along a circumferential direction centering on a rotation axis of the rotor.
A rotor structure including a rotor core in which a plurality of electromagnetic steel sheets are stacked and a plurality of permanent magnets disposed on the rotor core and constituting a magnetic pole is axially aligned in a plurality of stages, and the rotation of each stage A manufacturing method of a permanent magnet type motor provided with a rotor of a skew structure in which a child structure is disposed circumferentially offset,
Laminating the plurality of electromagnetic steel sheets to form the rotor core;
Placing the permanent magnet in a magnet insertion hole formed in the rotor core;
Passing a rivet through the rivet insertion hole formed in the rotor core, and skewing the steps to form the rotor structure of each step;
And a process of caulking and fastening with the rivets,
The method of manufacturing a permanent magnet type motor, wherein the rivet insertion hole is an elongated hole along a circumferential direction around a rotation axis of the rotor.
The permanent magnet according to claim 10 or 11, wherein the elongated hole shape of the rivet insertion hole has a shape slightly larger than an outer shape of a locus formed by moving a circle having the same diameter as the rivet in the circumferential direction. Manufacturing method of magnet type motor.
A shape obtained by connecting the outer shape of the shape obtained by displacing and arranging the circle having the same diameter as the rivet in the circumferential direction of the rotor structure of each stage by the skew angle of the rotor construction body of each stage. A method of manufacturing a permanent magnet type motor according to claim 10 or 11, wherein
The angular width θr of the rivet insertion hole around the rotation axis is
θ skew ≦ θ r ≦ 360 ° / (2 × P)
The method of manufacturing a permanent magnet type motor according to any one of claims 10 to 13, wherein the following relationship is satisfied.
And a magnetizing step of applying a magnetic force to the permanent magnet inserted into the magnet insertion hole,
The permanent magnet type according to any one of claims 9 to 14, wherein after the magnetizing step is carried out, the step of skewing of each step is performed to form the rotor structure of each step. Motor manufacturing method.
The axial dimension of the state in which the permanent magnets are arranged in a plurality of stages is set to be shorter than the axial dimension of the rotor core before fastening with the rivet, and the permanent magnet is fixed to the rotor core With the magnets disposed, a part of the permanent magnet of each stage is in a state of having entered into the rotor core of another adjacent stage,
The permanent magnet is chamfered at both end portions in the axial direction at each of the tip end surface and the rear end surface in the circumferential direction, and moves the rotor core in the circumferential direction in order to skew the rotor structure. When the chamfered portion of the permanent magnet contacts the rotor core of the adjacent step, the permanent magnet is fed in the circumferential direction while moving in the axial direction in the magnet insertion hole, A method of manufacturing a permanent magnet type motor according to any one of claims 9 to 15, wherein a rotor structure moves in the circumferential direction.
The dimension C of the chamfering is such that when the number of stages is N and the axial dimensional difference between the rotor structure of each stage and the permanent magnet of each stage is Δ,
C ≧ N / (N-1) × Δ
The method of manufacturing a permanent magnet type motor according to claim 16, which is
18. The rotor core according to claim 9, wherein each of the rotor cores in each stage is integrally formed in the axial direction before the step of laminating the plurality of electromagnetic steel sheets to form the rotor core. A manufacturing method of a permanent magnet type motor given in any 1 paragraph.
A permanent magnet type motor according to any one of claims 1 to 8.
A compression mechanism unit connected to the permanent magnet type motor via the rotating shaft and compressing a refrigerant by a driving force transmitted via the rotating shaft;
With a compressor.