JP3485910B2 - Hermetic compressor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor electric motor having a magnetic body in a rotor, and more particularly to an improved structure of the rotor.

[0002]

2. Description of the Related Art Generally, as a conventional rotor structure of a compressor electric motor, there is a structure described in JP-A-57-52359. In the one described in this publication, a rotor core and a magnetic body (permanent magnet), which are laminated in advance in a metal pipe, are arranged, and then these pipe, rotor core and magnetic body are integrally formed by die casting. It was a thing.

Another conventional technique is Japanese Patent Laid-Open No. 2-2.
There was a thing as described in 46748 gazette. The one described in this publication also has a rotor core pre-laminated in a metal pipe in the same manner as that described in the above publication,
After arranging a magnetic body (permanent magnet), these rotor cores were integrally configured by clamp pins.
At this time, an air gap portion is formed by a gap between the adjacent magnetic bodies to ensure pole separation of the magnetic bodies and improve efficiency.

As another conventional technique, Japanese Patent Publication No. 60
Some of them are described in Japanese Patent No. 23584.
What is described in this publication is one in which a magnetic body serving as a magnetic pole is inserted (embedded) in an iron core of a rotor. In particular, the one disclosed in this publication relates to a self-startable synchronous motor.

Further, as another conventional technique, Japanese Patent Application Laid-Open No. Hei 4-
Some of them are described in Japanese Patent No. 185247.
What is described in this publication is a rotor configured by embedding a magnetic material in the salient pole portion of a rotor core having a salient pole structure. In particular, the one disclosed in this publication has a rotor core in which a magnetic material is embedded and end face members covering both end faces of the rotor core are press-fitted into a rotary shaft to be integrally configured.

[0006]

In the rotor of the conventional compressor electric motor (brushless DC motor) configured as described above, a ferrite magnet material such as strontium ferrite is used as the magnetic material forming the field. It was being done. Although this ferrite-based magnet material has advantages such as a larger coercive force Hc and a lower price per unit weight of the raw material than the alnico-based magnet material, the residual magnetic flux density Br is at most about 0.4 (T ) And the magnetic energy product is small. Therefore, in order to increase the number of magnetic fluxes in the gap and obtain the required output, it is necessary to increase the size of the rotor and increase the area of the gap.

Here, the diameter of the rotor core is changed,
It is practically difficult to change the outer diameter of the airtight container of the compressor because it leads to a large-scale change of manufacturing equipment and the like. Therefore, the expansion of the size of the rotor is generally dealt with by expanding the size in the axial direction rather than the expansion of the diameter of the rotor. In the case of the conventional ferrite magnet material, the diameter D of the rotor core and the rotation The ratio L / D to the dimension L in the axial direction was 1.2 to 1.4.

However, since the rotary shaft of the compressor electric motor of this type is a cantilever type held by the bearing of the compression element portion, when the size of the rotor in the rotary shaft direction becomes large as described above, the rotation speed becomes particularly high. There is a problem that a large shake occurs at times, vibration and noise increase, and reliability and operating efficiency both decrease.

The present invention has been made in order to solve the above-mentioned conventional technical problems, and the size of the rotor of the compressor electric motor is reduced while maintaining the required output, and its reliability and The purpose is to improve operating efficiency.

[0010]

According to the present invention, a compression element and an electric motor for rotationally driving the compression element via a rotary shaft are housed in a closed container, and the compression element is fixed to an inner wall of the closed container. Child and electromagnetic steel plates with a thickness of 0.3 mm to 0.7 mm are laminated so that the product thickness dimension / outer diameter is smaller than 1.1, and fixed to the rotating shaft that is cantilevered by the bearing on the compression element side. The rotor includes a magnetic body made of a rare earth magnet material that rotates the rotor around a rotation axis in response to a magnetic field generated from the stator.

Further, the ratio t / l between the thickness t of the magnetic body and the dimension l in the direction of the rotation axis is made smaller than 0.08.

FIG. 7 shows demagnetization curves of a ferrite magnet material and a rare earth magnet material, which are permanent magnets used as a magnetic material forming a field, with the vertical axis representing the magnetic flux density B and the horizontal axis representing the coercive force H.
c is shown. In the figure, a broken line shows a general ferrite magnet material, and a solid line shows a general rare earth magnet material. T1 is + 25 ° C. and T2 is +
In each case at 150 ° C. As can be seen from the figure, the rare earth magnet material has a larger residual magnetic flux density Br and coercive force Hc than the ferrite magnet material, and the magnetic energy product is also extremely large. Therefore, even if the magnet area is reduced, the required number of gap magnetic fluxes can be secured, and a desired output can be obtained.

Therefore, in the present invention, since the magnetic material 45 provided in the laminated rotor core 26 is the rare earth magnet material, the required output is higher than that of the conventional ferrite magnet material. It becomes possible to reduce the axial dimension of the rotor core 26 while maintaining
It is possible to improve the reliability and the operation efficiency by reducing the vibration and noise generated by the vibration of the rotor and the contact of the rotor with the stator.

In particular, the diameter D of the rotor core 26 and the rotating shaft 6
Since the ratio L / D to the dimension L in the direction is made smaller than 1.1 and the dimension reduction of the rotor core 26 is applied exclusively to the dimension L reduction in the direction of the rotating shaft 6, the diameter of the rotor core 26, or It becomes possible to eliminate the need to change the manufacturing equipment or the like by changing the outer diameter of the closed container 1 of the compressor C.

Further, by using an electromagnetic steel sheet having a thickness of 0.3 mm to 0.7 mm, the eddy current generated on the surface of the rotor can be sheared and the temperature rise of the magnetic material can be suppressed.

If the ratio t / l between the thickness t of the magnetic body 45 and the dimension l in the direction of the rotary shaft 6 is set to be smaller than 0.08, a relatively expensive rare earth magnet material can be obtained. It is possible to eliminate or minimize the cost increase due to the use.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a vertical sectional side view of a compressor C to which the present invention is applied. In this figure, 1 is a closed container,
An electric motor (brushless DC motor) 2 is housed on the upper side of the inside, and a compression element 3 rotatably driven by the electric motor 2 via a rotary shaft is housed on the lower side. The hermetically sealed container 1 is a container that is previously divided into two parts, and the electric motor 2 and the compression element 3 are housed therein, and then hermetically sealed by high frequency welding or the like.

The electric motor 2 is composed of a stator 4 fixed to the inner wall of the hermetic container 1, and a rotor 5 supported inside the stator 4 so as to be rotatable around a rotation shaft 6. . The stator 4 is provided with a stator winding 7 that gives a rotating magnetic field to the rotor 5.

The compression element 3 comprises a first rotary cylinder 9 and a second rotary cylinder 10 which are partitioned by an intermediate partition plate 8. Eccentric parts 11 and 12 that are rotationally driven by the rotary shaft 6 are attached to the respective cylinders 9 and 10, and the eccentric parts 11 and 12 are eccentric with respect to each other by 180 degrees in phase.

Reference numerals 13 and 14 are a first roller and a second roller which rotate in the cylinders 9 and 10, respectively, and rotate inside the cylinders by rotation of the eccentric portions 11 and 12, respectively. 15,
Reference numerals 16 are a first frame body and a second frame body, respectively. The first frame body 15 forms a compression space in which the cylinder 9 is closed between the first frame body 15 and the partition plate 8, and the second frame body 16 is the same. A closed compression space of the cylinder 10 is formed between the partition 10 and the partition plate 8. The first frame body 15 and the second frame body 16 respectively include bearing portions 17 and 18 that rotatably support the lower portion of the rotary shaft 6.

Reference numerals 19 and 20 denote discharge mufflers, which are attached so as to cover the first frame 15 and the second frame 16, respectively. The cylinder 9 and the discharge muffler 19 are communicated with each other through a discharge hole (not shown) provided in the first frame body 15, and the cylinder 10 and the discharge muffler 20 are also connected to the second frame body 1.
The discharge holes (not shown) provided in 6 communicate with each other.
Reference numeral 21 is a bypass pipe provided outside the closed container 1 and communicates with the inside of the discharge muffler 20.

Reference numeral 22 is a discharge pipe provided on the closed container 1, and 23 and 24 are suction pipes connected to the cylinders 9 and 10, respectively. Further, reference numeral 25 is a closed terminal for supplying electric power from the outside of the closed container 1 to the stator winding 7 of the stator 4 (the lead wire connecting the closed terminal 25 and the stator winding 7 is not shown). No).

FIG. 2 is a partially longitudinal side view of the rotor 5 shown in FIG. 1, and FIG. 3 is a plan view (state before being pressed into the rotary shaft 6). In each drawing, 26 is a rotor core, and a plurality of rotor iron plates 27 punched in a shape as shown in FIG. 4 from electromagnetic steel plates having a thickness of 0.3 mm to 0.7 mm are laminated and caulked together to be integrated. It is laminated (it may be integrated by welding instead of caulking).

The rotor iron plate 27 is punched out from an electromagnetic steel plate so that salient pole portions 28 to 31 forming quadrupole magnetic poles are formed as shown in FIG. 4, and 32 to 35 are salient poles. It is a notch provided so that a salient pole portion is formed between the portions 28 to 31. At this time, each salient pole portion 28-3
The outer diameter D between the vertices of 1 is in the range of 40 mm to 70 mm, and is 50 mm in the embodiment.

Reference numerals 41 to 44 are insertion holes for press-fitting a magnetic body 45 (permanent magnet), which will be described later, and salient pole portions 28 to 3 respectively.
Corresponding to No. 1, on the outer peripheral side of the rotor iron plate 27, the rotor iron plate 27 is concentrically provided along the axial direction of the rotary shaft 6. The narrow path width d between the sidewalls of the salient pole portions 28 to 31 adjacent to the insertion holes 41 to 44 is set to 0.3 mm or more and less than 0.5 mm.

Reference numeral 46 is a hole which is formed in the center of the rotor iron plate 27 and in which the rotary shaft 6 is shrink-fitted. 47-50
Is a through hole having a size and shape through which rivets 51 to 54 for caulking, which will be described later, are inserted, and is formed corresponding to the inside of each of the insertion holes 41 to 44. Reference numerals 56 to 59 are caulking portions for caulking and fixing the rotor iron plates 27 to each other, and the insertion holes 41 to 44 are substantially concentric with the through holes 47 to 50.
Is formed between. Further, 61 to 64 are holes for forming oil passages formed inside the caulked portions 56 to 59.

A plurality of iron plates 27 for rotors are laminated and caulked at the caulking portions 56 to 59 to be integrated with each other to form a rotor iron core 26 as shown in the side view of FIG. . At this time, the outer diameter of the rotor core 26 is the outer diameter D (50 mm) of the above-described rotor iron plate 27, and the stacking dimension L in the direction of the rotating shaft 6 is, for example, 40 mm. Here, the ratio L / D of the outer diameter D and the dimension L is 1.
It is formed to be smaller than 1, and is 0.8 in the embodiment. That is, the dimension L in the direction of the rotating shaft 6 is set to be small.

On the other hand, the magnetic body 45 is made of a rare earth magnet material such as a praseodymium magnet or a neodymium magnet whose surface is plated with nickel.
The outer shape is rectangular as shown in FIG. The thickness t of the magnetic body 45 is, for example, 2.65 mm, and the dimension 1 in the direction of the rotation axis 6 is 40 mm, which is the same as the dimension L described above.
And Here, the ratio t / l of the thickness t and the dimension l is 0.
It is formed to be smaller than 08, and is 0.06 in the embodiment.
6 (note that each of the insertion holes 41 to 44 corresponds to the magnetic body 45).
Has been sized to be press-fitted exactly).

Reference numerals 66 and 67 denote flat plate-shaped end face members to be attached to the upper and lower ends of the rotor core 26, which are made of a non-magnetic material such as aluminum or a resin material to have substantially the same shape as the rotor iron plate 27. There is. The outer diameters of the end surface members 66 and 67 are made equal to or slightly smaller than the outer diameter D of the rotor core 26. Further, through holes 71 to 74 are formed in the end surface members 66 and 67 at positions corresponding to the through holes 47 to 50, and holes 76 are provided at positions corresponding to the holes 59 and 61 to 64.
And 77 to 80 are perforated.

Then, the insertion holes 41 to 4 of the rotor core 26 are inserted.
After press-fitting the magnetic body 45 into the inside 4, the upper and lower end face members 6
6 and 67 are set to close the upper and lower sides of the insertion holes 41 to 44.
In this state, the through holes 47 to 50 and 71 to 74 penetrate the rotor core 26 and the end surface members 66 and 67 along the direction of the rotation axis 6. The holes 61 to 64 and 77 to 80 penetrate the rotor core 26 and the end surface members 66 and 67. After that, the rivets 51 to 54 are inserted into the through holes 47 to 50 and 71 to 74, and the upper and lower parts are caulked to be integrally formed. Incidentally, A is a balance weight, which is fixed to the rotor core 26 by the rivets 51 together with the upper end surface member 66.

When a direct current is applied to the stator winding 7 of the stator 2 having the above structure, the rotor 5 is applied to the stator winding 7 by the repulsion / suction action with the magnetic field generated by the magnetic body 45. Speed at which voltage and load are balanced (for example, 500 rpm to 10000 rpm by changing applied voltage)
It is variable within the range of 4). The rotation of the rotor 5 causes the rotation shaft 6 to rotate, which causes the eccentric portions 11 and 12 to rotate, whereby the first and second rollers 13 and 14 rotate to exert a compression action.

At this time, since the rotary shaft 6 is a cantilever type which is rotatably supported by the lower bearing portions 17 and 18, as described above, when the size of the rotor 5 in the rotary shaft 6 direction becomes large, as described above, Large vibrations occur at high speed, vibration and noise increase, and reliability and operating efficiency both decrease.

However, in the present invention, the rotor core 26
Since the magnet material 45 provided therein is a rare earth magnet material having a large residual magnetic flux density Br and a coercive force Hc and an extremely large magnetic energy product as compared with the ferrite magnet material, a conventional ferrite magnet material is used. Compared to the case where the above, the size of the rotor core 26 can be reduced while maintaining the required output. Therefore, it is possible to reduce vibration and noise generated by the vibration of the rotor 5, and to improve reliability and operation efficiency.

Particularly, as described above, the diameter D of the rotor core 26 is
Since the ratio L / D between the dimension L in the direction of the rotating shaft 6 is made smaller than 1.1 and the dimension reduction of the rotor core 26 is applied exclusively to the dimension L in the direction 6 of the rotating axis, the rotor core 26 The diameter of
Alternatively, it becomes possible to eliminate the need to change the manufacturing equipment or the like by changing the outer diameter of the closed container 1 of the compressor C.

Further, if the ratio t / l of the thickness t of the magnetic body 45 and the dimension l in the direction of the rotating shaft 6 is made smaller than 0.08 by taking advantage of the characteristics of the rare earth magnet material, it is relatively expensive. It is also possible to eliminate or minimize the cost increase caused by using such rare earth magnet material.

[0036]

As described above in detail, in the present invention, the magnetic material provided in the laminated rotor iron core is the rare earth magnet material, so that it is more advantageous than the conventional ferrite magnet material. Thus, the axial dimension of the rotor core can be reduced while maintaining the required electric motor output. Therefore, the center of gravity of the rotor is brought closer to the cantilevered bearing portion, vibration and noise generated by the vibration of the rotor can be reduced, and reliability and operating efficiency can be improved.

In particular, if the ratio L / D between the diameter D of the rotor core and the dimension L in the direction of the rotation axis is made smaller than 1.1, the dimension reduction of the rotor core is reduced exclusively in the direction L of the rotation axis. This makes it possible to reduce the noise and vibration of the hermetic compressor without changing the diameter of the rotor core or the manufacturing equipment by changing the outer diameter of the hermetic container of the compressor.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a compressor to which the present invention is applied.

FIG. 2 is a partially longitudinal side view of the rotor of the present invention.

FIG. 3 is a plan view of the rotor of the present invention.

FIG. 4 is a plan view of a rotor iron plate that constitutes the rotor of the present invention.

FIG. 5 is a side view of a rotor core that constitutes the rotor of the present invention.

FIG. 6 is a perspective view of a magnetic body forming the rotor of the present invention.

FIG. 7 is a diagram showing a demagnetization curve of a permanent magnet used as a magnetic body.

[Explanation of symbols]

C compressor 2 electric motor 4 stator 5 rotor 6 rotation axes 26 rotor core 27 Iron plate for rotor 32, 33, 34, 35 Notches 45 Magnetic

Front page continuation (72) Inventor Keijiro Igarashi 2-5-5 Keihan Hondori, Moriguchi City, Osaka Prefecture Sanyo Electric Co., Ltd. (72) Inventor Kazuhiko Arai 2-5-5 Keihan Hondori, Moriguchi City, Osaka Prefecture Sanyo Electric Co., Ltd. (56) Reference JP 63-69450 (JP, A) JP 57-180359 (JP, A) JP 7-236239 (JP, A) JP 5-175038 ( JP, A) JP 5-122877 (JP, A) JP 4-261346 (JP, A) JP 4-255439 (JP, A) JP 3-285538 (JP, A) JP Flat 2-157492 (JP, A) Actual flat 5-88165 (JP, U) Actual flat 5-4743 (JP, U) Actual flat 5-4741 (JP, U) Actual flat 4-128056 (JP , U) Furukaihei 4-164 (JP, U) International Publication 92/007409 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02K 1/27 F04B 39/00 H02K 1 / 22 H02K 21/14

Claims (2)

(57) [Claims] 1. A hermetically-sealed container accommodates a compression element and an electric motor that rotationally drives the compression element via a rotary shaft, and a stator for fixing the compression element to an inner wall of the hermetically-sealed container and a thickness of 0. From a rotor fixed to a rotary shaft that is cantilevered by the bearing portion on the compression element side, by stacking electromagnetic steel sheets of 3 mm to 0.7 mm so that the product thickness dimension / outer diameter is smaller than 1.1 And the rotor has a rotating shaft
A hermetic compressor comprising a magnetic body made of a rare earth magnet material that is swallowed and rotates the rotor around a rotation axis according to a magnetic field generated from the stator. 2. The hermetic compressor according to claim 1, wherein the ratio t / l of the thickness t of the magnetic body and the dimension l in the direction of the rotation axis is smaller than 0.08.