JP2005143300A - Dynamo-electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor driven compressor which can substantially reduce noises by small generating a contact area of a stator with a shell part. <P>SOLUTION: An electric motor element (the dynamo-electric motor) 2 is constituted by a stator 4 having a stator core 74 brought into contact with an inner wall of a sealed vessel 1 to be fixed thereto and a rotor 5 having a magnetic material 45 to be mounted in a rotary shaft 6 to be rotatably supported in an inner side of the stator 4. In the case of assuming H for the dimension of a part with the stator core 74 abutting the sealed vessel 1 in a direction of the rotary shaft 6 and Ho for the dimension of the concerned stator core 74 in the direction of the rotary shaft 6, a relation H<Ho is determined. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electric compressor in which an electric element is housed in a container.

  Conventionally, this kind of electric compressor is shown, for example, in Patent Document 1 and Patent Document 2 filed earlier by the applicant. In these conventional electric compressors, induction motors or DC motors are used. However, when the DC motor is a rare earth permanent magnet motor, the permanent magnet, rotor, and stator have the same thickness, and ferrite In the case of a permanent magnet motor, it is designed to rotate from the stator and have a high permanent magnet thickness.

  Next, this conventional electric compressor 100 will be described with reference to FIGS. In the figure, reference numeral 101 denotes an airtight container. A compression element 103 that is rotationally driven by the electric motor 102 is housed below the electric motor (for example, DC motor) 102 as an electric element on the upper side. The sealed container 101 has a two-part configuration including a cylindrical shell portion 101A having an upper end opened and an end cap portion 101B closing the upper end opening of the shell portion 101A. The motor 102 and the compression element are contained in the shell portion 101A. After housing 103, the end cap portion 101B is placed on the shell portion 101A and sealed by high-frequency welding or the like. Further, the bottom portion in the shell portion 101A of the sealed container 101 becomes an oil reservoir SO.

  The electric motor 102 includes a stator 104 fixed to the inner wall of the hermetic container 101, and a rotor 105 supported inside the stator 104 so as to be rotatable about a rotation shaft 106. The stator 104 is a stator core 174 configured by laminating a plurality of substantially donut-shaped stator iron plates, and a plurality of teeth formed on the inner periphery of the stator core 174 by a distributed winding method. A stator winding (drive coil) 107 that is mounted and applies a rotating magnetic field to the rotor 105 is configured. The outer peripheral surface of the stator core 174 is fixed in contact with the inner wall of the shell portion 101 </ b> A of the sealed container 101.

  In this case, a plurality of notches 176 are formed on the outer peripheral surface of the stator core 174, and the notches 176 are separated from the inner wall of the shell portion 101 </ b> A and constitute a passage 177 there.

  The compression element 103 includes a first rotary cylinder 109 and a second rotary cylinder 110 that are partitioned by an intermediate partition plate 108. Eccentric portions 111 and 112 that are rotationally driven by the rotating shaft 106 are attached to the cylinders 109 and 110, and the eccentric positions 111 and 112 are 180 degrees out of phase with each other.

  Reference numerals 113 and 114 denote a first roller and a second roller that rotate in the cylinders 109 and 110, respectively, and rotate in the cylinder by the rotation of the eccentric portions 111 and 112, respectively. Reference numerals 115 and 116 denote a first frame body and a second frame body, respectively. The first frame body 115 forms a closed compression space of the cylinder 109 between the partition plate 108 and the second frame body 116. Similarly, a compression space in which the cylinder 110 is closed is formed between the partition plate 108 and the partition plate 108. Further, the first frame body 115 and the second frame body 116 include bearing portions 117 and 118 that rotatably support the lower portion of the rotation shaft 106, respectively.

  Reference numerals 119 and 120 denote cup mufflers, which are attached to cover the first frame body 115 and the second frame body 116, respectively. The cylinder 109 and the cup muffler 119 are communicated with each other through a communication hole (not shown) provided in the first frame body 115, and the cylinder 110 and the cup muffler 120 are also communicated (not shown) provided on the second frame body 116. It communicates with a hole. Reference numeral 121 denotes a bypass pipe provided outside the sealed container 101 and communicates with the inside of the cup muffler 120.

  Reference numeral 122 denotes a discharge pipe provided on the sealed container 101, and reference numerals 123 and 124 denote suction pipes connected to the cylinders 109 and 110, respectively. Reference numeral 125 denotes a hermetic terminal for supplying electric power from the outside of the hermetic container 101 to the stator winding 107 of the stator 104 (the lead wire connecting the hermetic terminal 125 and the stator winding 107 is not shown). )

  A rotor core 126 of the rotor 105 is formed by laminating a plurality of rotor iron plates in which electromagnetic steel plates having a thickness of 003 mm to 007 mm are punched into a predetermined shape, and crimping each other to integrally laminate them.

  In this case, the rotor iron plate of the rotor core 126 is punched from the magnetic steel sheet so that the salient pole portions 128, 129, 130, 131 constituting the four poles are formed, and 132, 133, 134, A concave portion 135 is provided so that salient pole portions are formed between the salient pole portions 128, 129, 130, and 131.

  Reference numerals 141, 142, 143, and 144 denote slots for inserting magnetic bodies 145 (permanent magnets), corresponding to the salient pole portions 128, 129, 130, and 131, and on the outer peripheral side of the rotor core 126, the rotating shaft It is drilled concentrically along the axial direction of 106.

  Reference numeral 146 denotes a hole formed at the center of the rotor core 126 and into which the rotating shaft 106 is shrinked. Then, after a plurality of rotor iron plates are stacked, the rotor core 126 is formed by caulking and integrating each other.

  The magnetic body 145 is made of, for example, a praseodymium permanent magnet or a rare earth permanent magnet material such as a neodymium permanent magnet whose surface is plated with nickel, and its outer shape is rectangular as a whole. It is made into a shape. Each of the slots 141, 142, 143, and 144 has a size into which the magnetic body 145 is inserted. Reference numerals 166 and 167 denote flat end surface members attached to the upper and lower ends of the rotor core 126, and are formed in a substantially disk shape from a nonmagnetic material such as stainless steel or brass.

  Reference numeral 172 denotes a disk-like oil separation plate positioned above the end face member 166 and attached to the rotor 105. Reference numeral 173 denotes a balance weight attached between the plate 172 and the end face member 166.

  With this configuration, when the stator winding 107 of the stator 104 of the electric motor 102 is energized, a rotating magnetic field is formed and the rotor 105 rotates. The rotation of the rotor 105 causes the rollers 113 and 114 in the cylinders 109 and 110 to rotate eccentrically via the rotation shaft 106, and the suction gas sucked from the suction pipes 123 and 124 is compressed.

  The compressed high-pressure gas is discharged from the cylinder 109 into the cup muffler 119 through the communication hole, and is discharged into the sealed container 101 from a discharge hole (not shown) formed in the cup muffler 119. On the other hand, the cylinder 110 is discharged to the cup muffler 120 through the communication hole, and is discharged into the sealed container 101 through the bypass pipe 121.

  The discharged high-pressure gas passes through the gap in the electric motor 102, reaches the discharge pipe 122, and is discharged to the outside. On the other hand, although the gas contains oil, the oil is separated by the plate 172 or the like before reaching the discharge pipe 122, and is directed outward by centrifugal force and flows down to the oil reservoir SO through the passage 177 and the like. Met.

In the electric motor 102 provided in the electric compressor 100, when the magnetic body 145 is a rare earth permanent magnet, the product thickness of the permanent magnet, the rotor 105, and the stator 104 is substantially the same. In the case of a ferrite permanent magnet, the rotor 105 and the permanent magnet have a higher thickness than the stator 104.
Japanese Patent Laid-Open No. 10-288180 Japanese Patent Application No. 5-350444

  However, a DC motor (electric motor) used for an electric compressor has a greater magnetic attraction / repulsion force of the stator in the radial direction than a normal induction motor. For this reason, the yoke part of the electric motor is vibrated, which causes a noise increase of the electric compressor. In particular, motors using high-magnetism rare earth permanent magnets and motors with concentrated magnetic poles with a small number of slots have a problem that noise reduction is a major issue because the change in magnetic flux is larger than motors with a large number of slots. .

  In addition, the vibration generated by the teeth of the stator core vibrates the yoke portion of the stator and directly vibrates the shell portion at the contact portion with the shell portion. This also has a problem that causes the noise of the electric compressor to increase.

  The present invention has been made to solve the problems of the related art, and provides an electric motor capable of greatly reducing noise by reducing the contact area between the stator and the shell portion. Objective.

That is, the electric motor of the invention of claim 1 is an electric motor comprising an electric element housed in a container and a compression element driven by a rotating shaft connected to the electric element.
A stator having a stator core fixed to a part of the electric element abutting against an inner wall of the container and spaced apart from the other; and a magnetic body attached to the rotating shaft; And the dimension of the stator core in the direction of the rotation axis of the portion where the stator core contacts the container is H, and the dimension of the stator core in the direction of the rotation axis When Ho is Ho, H <Ho.

Further, the electric motor of the invention of claim 2 is an electric motor comprising an electric element housed in a container and a compression element driven by a rotary shaft connected to the electric element.
A stator having a stator core fixed to a part of the electric element abutting against an inner wall of the container and spaced apart from the other; and a magnetic body attached to the rotating shaft; And the dimension of the portion of the stator core in contact with the container in the direction of the rotational axis H, and the dimension of the stator core in the direction of the rotational axis. Ho, where H <Ho and Hmg <Ho, when the dimension of the magnetic material in the direction of the rotation axis is Hmg.

  As described above in detail, according to the first aspect of the present invention, a stator having a stator core fixed to a part of the electric element in contact with the inner wall of the container and spaced apart from the other part, and a magnetic body. And a rotor that is rotatably attached to the inner side of the stator and that is rotatably supported on the inner side of the stator. When Ho is the dimension in the direction of the rotation axis of the iron core, since H <Ho, the transmission of vibrations from the stator core to the shell portion can be reduced. Thereby, for example, even when the yoke part of the stator is vibrated, vibration transmission to the shell part can be reduced. Therefore, the noise of the electric motor can be greatly reduced.

  According to a second aspect of the invention, there is provided a stator having a stator core fixed to a part of the electric element in contact with the inner wall of the container and spaced apart from the other part, and a magnetic body. The rotor is attached to the rotating shaft and is supported rotatably inside the stator, and the dimension in the rotating shaft direction of the portion where the stator core contacts the container is H, and the rotation of the stator core If the dimension in the axial direction is Ho and the dimension in the rotation axis direction of the magnetic body is Hmg, since H <Ho and Hmg <Ho, transmission of vibration from the stator core to the shell portion can be reduced. However, the magnetic force of the magnetic material can be dispersed in the direction of the rotation axis of the stator core. Therefore, the noise of the electric motor can be further greatly reduced.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal side view of the electric compressor C of the present invention, and FIG. 2 is a cross-sectional top view of the electric compressor C. In this figure, 1 is a sealed container constituting a cooling device provided in a freezer, a refrigerator, a showcase or the like, and an electric motor 2 as an electric element on the upper side inside, and a compression driven to rotate by this electric motor 2 on the lower side. Element 3 is housed. The hermetic container 1 has a two-part configuration including a cylindrical shell portion 1A having an upper end opened and an end cap portion 1B closing the upper end opening of the shell portion 1A. The motor 2 and the compression element are contained in the shell portion 1A. After storing 3, the end cap portion 1B is covered with the shell portion 1A and sealed by high frequency welding or the like. Moreover, the bottom part in the shell part 1A of the sealed container 1 becomes an oil reservoir SO.

  The electric motor 2 is a so-called magnetic pole concentrated winding direct winding DC brushless motor, and is supported by a stator 4 fixed to the inner wall of the hermetic container 1 and a rotating shaft 6 around the stator 4 so as to be rotatable. And the rotor 5. The stator 4 includes a stator core 74 configured by laminating a plurality of substantially donut-shaped stator iron plates (silicon steel plates), and a stator winding (drive coil) for applying a rotating magnetic field to the rotor 5. 7.

  Although not shown, six tooth portions are provided on the inner periphery of the stator core 74, and a slot portion 78 that is open inwardly and vertically is formed between the tooth portions. Then, by winding the stator winding 7 directly on the teeth using the space of the slot portion 78, the magnetic poles of the stator 4 are formed by a so-called concentrated direct winding method, so that four poles and six slots are formed. The stator 4 is configured.

  The outer peripheral surface of the stator core 74 is fixed in contact with the inner wall of the shell portion 1 </ b> A of the sealed container 1. In this case, if the dimension of the portion of the stator core 74 in contact with the hermetic container 1 in the direction of the rotation axis 6 is H and the dimension of the stator core 74 in the direction of the rotation axis 6 is Ho, H <Ho. It is configured. A plurality of notches 76 (six in the embodiment) are formed on the outer peripheral surface of the stator core 74 in a chordal manner, and the notches 76 are separated from the inner wall of the shell portion 1A. As will be described later, an oil return passage 77 is formed.

  3 is a partially longitudinal side view of the rotor 5 shown in FIG. 1, and FIG. 4 is a plan view (a state before being press-fitted into the rotary shaft 6). In each figure, reference numeral 26 denotes a rotor core, which is formed by laminating a plurality of rotor iron plates 27 punched out from a 0.3 to 0.7 mm thick electromagnetic steel sheet into a shape as shown in FIG. They are laminated (in addition, they may be integrated by welding without using caulking).

  As shown in FIG. 5, the rotor iron plate 27 is punched from a magnetic steel sheet so that salient pole portions 28 to 31 constituting four poles are formed, and 32 to 35 are salient pole portions 28 to 31. It is a recessed part provided so that a salient pole part may be formed between 31. The outer diameter (diameter) D between the vertices of the salient pole portions 28 to 31 is, for example, 50 mm in the 15-frame compressor. In addition, the outer surface of the salient pole portions 28 to 31 on the rotation direction (rotation direction of the rotor 5, clockwise in the embodiment in FIG. 5) side is cut inward and obliquely within a predetermined range, and the cut portion 36. -39 are formed. When the rotor 5 is designed to rotate counterclockwise, the cut portions 36 to 39 are formed by cutting away the opposite side of the rotation direction. That is, the opposite side of FIGS. 4 and 5 is excised.

  Reference numerals 41 to 44 denote slots for press-fitting magnetic bodies 45 (permanent magnets), which will be described later, corresponding to the salient pole portions 28 to 31, in the axial direction of the rotary shaft 6 on the outer peripheral side of the rotor iron plate 27. Along the concentric circles. The narrow path width d between the side walls of the salient pole portions 28 to 31 adjacent to the slots 41 to 44 is set to 0.3 to 1.0 mm (0.5 mm in the embodiment).

  Reference numeral 46 denotes a hole formed at the center of the rotor iron plate 27 and into which the rotary shaft 6 is shrinked. Then, after laminating a plurality of rotor iron plates 27, the rotor iron core 26 is formed by caulking and integrating each other. Reference numerals 47 to 50 are through-holes having substantially the same size as the rivets 51 to 54 for caulking, which will be described later, and are formed corresponding to the insides of the slots 41 to 44. Reference numerals 56 to 59 denote caulking portions for caulking and fixing the rotor iron plates 27 to each other, and are formed between the slots 41 to 44 substantially concentrically with the through holes 47 to 50. Further, 61 to 64 are holes for forming oil passages drilled inside the caulking portions 56 to 59.

  A plurality of rotor iron plates 27 are laminated, and are caulked and integrated with each other in the caulking portions 56 to 59, thereby forming the rotor 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 rotor iron plate 27 described above, and the stacking dimension L in the direction of the rotating shaft 6 is, for example, 40 mm. Here, the ratio L / D between the outer diameter D and the dimension L is formed to be smaller than 1.1, 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 composed of, for example, a praseodymium magnet or a rare earth magnet material such as a neodymium magnet whose surface is plated with nickel, and its outer shape is rectangular as shown in FIG. . Each of the slots 41 to 44 is sized such that the magnetic body 45 is tightly press-fitted. The thickness t of the magnetic body 45 is, for example, 2.65 mm, and the dimension Hmg in the direction of the rotation axis 6 is 40 mm, which is the same as the dimension L described above. The ratio t / Hmg between the thickness t and the dimension Hmg is smaller than 0.1 (0.08 in the embodiment). That is, when the dimension of the magnetic body 45 in the direction of the rotation axis 6 is Hmg and the dimension of the stator core 74 in the direction of the rotation axis 6 is Ho, the configuration is such that Hmg <Ho. Reference numeral 72 denotes a disk-shaped oil separation plate positioned above the end face member 66 and attached to the rotor 5. Reference numeral 73 denotes a balance weight attached between the plate 72 and the end face member 66.

  Reference numerals 66 and 67 denote flat end face members attached to the upper and lower ends of the rotor core 26, and are formed in substantially the same shape as the rotor iron plate 27 from a nonmagnetic material such as aluminum or a resin material. The outer diameters of the end face members 66 and 67 are the same as or slightly smaller than the outer diameter D of the rotor core 26. Further, the end face members 66 and 67 are formed with through holes 81 to 84 at positions corresponding to the through holes 47 to 50. Holes 76 and 87 to 90 are formed at positions corresponding to the holes 59 and 61 to 64.

  Then, after the magnetic body 45 is press-fitted into the slots 41 to 44 of the rotor core 26, the upper and lower end surface members 66 and 67 are set to close the upper and lower sides of the slots 41 to 44. In this state, the through holes 47 to 50 and 81 to 84 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 87 to 90 pass through the rotor core 26 and the end surface members 66 and 67. Thereafter, the rivets 51 to 54 are inserted into the through holes 47 to 50 and 81 to 84, and the upper and lower parts are caulked to form a single body. A balance weight 73 is fixed to the rotor core 26 by a rivet 51 together with an upper end face member 66.

  The stator core 74 is provided with a notch 74A. The notch 74A is notched in a predetermined dimension in the extending direction of the rotating shaft 6 of the rotor 5 and is notched in a predetermined depth in the rotating shaft 6 direction. ing. In this case, the contact length between the stator core 74 and the inner wall of the shell portion 1A is H (H1 + H2 in the figure), and the thickness of the stator core 74 (in this case, the dimension of the rotor 5 in the direction of the rotation axis 6) is Ho. In this case, the ratio of the dimension H to the dimension Ho is 0.2 ≦ H / Ho ≦ 0.8.

  That is, both side portions H1 and H2 of the notch 74A provided in the extending direction of the rotating shaft 6 of the stator core 74 are brought into contact with the inner wall of the shell portion 1A, and the notch 74A is separated from the inner wall of the shell portion 1A. . Thereby, in the electric motor 2 (DC motor), the excitation of the yoke portion of the rotor 5 is transmitted to the shell portion 1A by the magnetic attraction / repulsion force of the rotor 5 in the radial direction as compared with a normal induction motor. It becomes difficult. Therefore, the noise of the electric compressor C can be reduced.

  On the other hand, the rotary compression element 3 includes a first rotary cylinder 9 and a second rotary cylinder 10 partitioned by an intermediate partition plate 8. Eccentric portions 11 and 12 that are rotationally driven by the rotating shaft 6 are attached to the cylinders 9 and 10, and the eccentric positions of the eccentric portions 11 and 12 are 180 degrees out of phase with each other.

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

  19 and 20 are cup mufflers, which are attached so as to cover the first frame 15 and the second frame 16, respectively. The cylinder 9 and the cup muffler 19 are communicated with each other through a communication hole (not shown) provided in the first frame 15, and the cylinder 10 and the cup muffler 20 are also provided with a communication (not shown) provided in the second frame 16. It communicates with a hole. In this embodiment, the inside of the cup muffler 20 on the lower surface communicates with the cup muffler 19 on the upper surface via a through hole 79 that penetrates the cylinders 9 and 10 and the intermediate partition plate 8.

  Reference numeral 22 denotes a discharge pipe provided on the closed container 1, and 23 and 24 denote suction pipes connected to the cylinders 9 and 10, respectively. Reference numeral 25 denotes a hermetic terminal for supplying electric power from the outside of the hermetic container 1 to the stator winding 7 of the stator 4 (the lead wire connecting the hermetic terminal 25 and the stator winding 7 is not shown). )

  With this configuration, when the stator winding 7 of the stator 4 of the electric motor 2 is energized, a rotating magnetic field is formed and the rotor 5 rotates. The rotation of the rotor 5 causes the rollers 13 and 14 in the cylinders 9 and 10 to rotate eccentrically via the rotating shaft 6, and the suction gas sucked from the suction pipes 23 and 24 is compressed.

  The compressed high-pressure gas is discharged from the cylinder 9 into the cup muffler 19 through the communication hole, and is discharged into the upper sealed container 1 from a discharge hole (not shown) formed in the cup muffler 19. . On the other hand, the cylinder 10 is discharged to the cup muffler 20 through the communication hole, enters the cup muffler 19 through a through hole (not shown), and is similarly discharged from the discharge hole into the upper sealed container 1. .

  The discharged high-pressure gas passes through a gap provided in the stator 4 of the electric motor 2, a gap between the stator core 74 and the rotor 5, and concave portions 32, 33, 34, 35 of the rotor core 26. Pass and rise. Then, the gas hits the plate 72, rises outward by centrifugal force, and is discharged from the discharge pipe 22.

  Next, a refrigerant circuit diagram of a cooling device using the electric compressor C according to FIG. 23 is shown. The outlet side of the electric compressor C is connected to a condenser 69, and the outlet side of the condenser 69 is connected to an expansion valve 70 as a pressure reducing device via a liquid receiver and a liquid pipe solenoid valve (not shown). The expansion valve 70 is connected to an evaporator 71, and an outlet side of the evaporator 71 constitutes an annular refrigerant circuit connected to the suction side of the electric compressor C via an accumulator. The high-temperature and high-pressure gas refrigerant discharged from the electric compressor C dissipates heat in the condenser 69 and is condensed and liquefied. And after depressurizing with the expansion valve 70, it enters into the evaporator 71 and repeats the cycle which takes heat from the surroundings and vaporizes there.

  The noise waveform of the electric compressor C is shown in FIG. From the figure, it can be seen that the noise in the hatched portion in the audible sound range (500 Hz to 1.6 kHz) is reduced. The electric compressor C uses a two-cylinder rotary compressor (twin rotary) 700 W, the refrigerant uses R401A, and the electric motor 2 uses concentrated winding and rare earth permanent magnets. Further, Ct / Et = 43 ° C./44° C. is operated at 80 Hz, and the microphone is horizontally installed at a position 1 m apart. The results are shown in Table 1 below.

It can be seen from the above table that the noise is reduced.

  As described above, the notch 74A is provided on the outer peripheral surface of the stator core 74 constituting the rotor 5 of the electric motor 2 (DC motor) used in the electric compressor C, and other than the notch 74A is applied to the inner wall of the shell 1A. The electric motor 2 (DC motor) used for the electric compressor C is in contact with the yoke portion of the rotor 5 by the magnetic attraction / repulsive force of the rotor 5 in the radial direction as compared with a normal induction motor. However, since the notch 74A is provided on the outer peripheral surface of the stator core 74 constituting the rotor 5 and the portions other than the notch 74A are in contact with the inner wall of the shell 1A, the yoke of the stator 4 Even when the portion is vibrated, vibration transmission to the shell portion 1A can be reduced. Therefore, the noise of the electric compressor C can be greatly reduced.

  Particularly, in a rare earth permanent magnet motor having a high magnetic force or a magnetic pole concentrated winding motor having a small number of slots, even when the change in magnetic flux is larger than that of a motor having a large number of slots, a notch 74A is provided on the outer peripheral surface of the stator core 74 to form a shell. Since it is in contact with the inner wall of the portion 1A, vibration transmission from the yoke portion of the stator 4 to the shell portion 1A can be reduced. As a result, similarly, the noise of the electric compressor C can be greatly reduced.

  Next, another electric compressor C is shown in FIGS. In this case, the outer surface of the stator core 74 is provided with a notch 74A that is notched in a predetermined dimension in the extending direction of the rotating shaft 6 of the rotor 5 and is notched in a predetermined depth in the rotating shaft 6 direction. . The notch 74A is notched at one end (lower side in the figure) from the center of the stator core 74 in the extending direction of the rotating shaft 6, and is notched at a predetermined depth in the rotating shaft 6 direction. In this case, the contact length between the stator core 74 and the inner wall of the shell portion 1A is H (H1 in the figure), and the thickness of the stator core 74 (in this case, the dimension of the rotor 5 in the direction of the rotation axis 6) is Ho. In this case, 0.2 ≦ H1 / Ho ≦ 0.8.

  That is, one side (H1 in the figure) of the notch 74A provided in the extending direction of the rotating shaft 6 of the stator core 74 is brought into contact with the inner wall of the shell 1A, and the notch 74A is separated from the inner wall of the shell 1A. I am letting. Except for the stator core 74, the configuration is the same as that shown in FIGS. Thereby, in the electric motor 2 (DC motor), the excitation of the yoke portion of the rotor 5 is transmitted to the shell portion 1A by the magnetic attraction / repulsion force of the rotor 5 in the radial direction as compared with a normal induction motor. It becomes difficult. Therefore, the noise of the electric compressor C can be reduced as described above.

  Next, another electric compressor C is shown in FIGS. In this case, the outer surface of the stator core 74 is provided with a notch 74A that is notched in a predetermined dimension in the extending direction of the rotating shaft 6 of the rotor 5 and is notched in a predetermined depth in the rotating shaft 6 direction. . The notch 74A is notched at one end (upper side in the drawing) from the center of the stator core 74 in the extending direction of the rotating shaft 6, and is notched at a predetermined depth in the rotating shaft 6 direction. In this case, the contact length between the stator core 74 and the inner wall of the shell portion 1A is H (H2 in the figure), and the stack thickness of the stator core 74 (in this case, the dimension in the direction of the rotation axis 6 of the rotor 5) is Ho. In this case, 0.2 ≦ H2 / Ho ≦ 0.8.

  That is, one side H2 of the notch 74A provided in the extending direction of the rotating shaft 6 of the stator core 74 is brought into contact with the inner wall of the shell 1A, and the notch 74A is separated from the inner wall of the shell 1A. Except for the stator core 74, the configuration is the same as that shown in FIGS. Thereby, in the electric motor 2 (DC motor), the excitation of the yoke portion of the rotor 5 is transmitted to the shell portion 1A by the magnetic attraction / repulsion force of the rotor 5 in the radial direction as compared with a normal induction motor. It becomes difficult. Therefore, the noise of the electric compressor C can be reduced as described above.

  Next, FIGS. 14 and 15 show another electric compressor C. FIG. In this case, the outer surface of the stator core 74 is provided with a notch 74A that is notched in a predetermined dimension in the extending direction of the rotating shaft 6 of the rotor 5 and is notched in a predetermined depth in the rotating shaft 6 direction. . The cutout portion 74A is cut out at a plurality of locations (in this case, two locations) in the extending direction of the rotating shaft 6 and is cut out at a predetermined depth in the rotating shaft 6 direction. In this case, the contact length between the stator core 74 and the inner wall of the shell portion 1A is H (H1 + H2 + H3 in the figure), and the thickness of the stator core 74 (in this case, the dimension in the direction of the rotation axis 6 of the rotor 5) is Ho. In this case, 0.2 ≦ H (H1 + H2 + H3) /Ho≦0.8.

  That is, the portions (H1, H2, H3 in the figure) other than the notches 74A, 74A provided in the extending direction of the rotating shaft 6 of the stator core 74 are brought into contact with the inner wall of the shell portion 1A and the notches 74A. Is spaced apart from the inner wall of the shell portion 1A. Except for the stator core 74, the configuration is the same as that shown in FIGS. Thereby, in the electric motor 2 (DC motor), the excitation of the yoke portion of the rotor 5 is transmitted to the shell portion 1A by the magnetic attraction / repulsion force of the rotor 5 in the radial direction as compared with a normal induction motor. It becomes difficult. Therefore, the noise of the electric compressor C can be reduced as described above.

  Next, another electric compressor C is shown in FIGS. In this case, the thickness of each magnetic body 45 (permanent magnet)... Inserted in each slot 41, 42, 43, 44 provided in the rotor 5 is set to the thickness of the stator core 74 (in this case, The dimension of the rotor 5 in the direction of the rotation axis 6 is shorter. And each magnetic body 45 ... inserted in each slot 41, 42, 43, 44 is located in the longitudinal direction center in each slot 41, 42, 43, 44. Further, when the thickness of the magnetic body 45 provided in the rotor 5 is Hmg and the thickness of the stator core 74 is Ho, the ratio of the dimension Hmg to the dimension Ho is 0.2 ≦ Hmg / Ho ≦ 0.98. It is comprised so that. That is, the magnetic bodies 45... Inserted into the slots 41, 42, 43, 44 have both ends of the slots 41, 42, 43, 44 shortened by the same dimension. Except for the magnetic body 45, the configuration is the same as that shown in FIGS. As a result, the motor 2 is less likely to transmit the vibration of the yoke portion of the rotor 5 to the shell portion 1A due to the magnetic attraction / repulsive force of the rotor 5 in the radial direction compared to a normal induction motor. Similarly, the noise of the electric compressor C can be reduced.

  FIG. 8 shows a demagnetization curve of a phyllite magnet material and a rare earth magnet material, which are permanent magnets used as the magnetic body 45 constituting the field, where the vertical axis indicates the magnetic flux density B and the horizontal axis indicates the holding force Hc. Yes. In the figure, the broken line indicates a general ferrite magnet material, the solid line indicates a general rare earth magnet material, T1 is + 25 ° C., and T2 is + 150 ° C. Is the case. As can be seen from the figure, the rare earth-based magnet material has both a large residual magnetic flux density Br and a holding force Hc, and an extremely large magnetic energy product, as compared with the ferrite-based magnet material. Therefore, the required number of gap magnetic fluxes can be secured even if the magnet area is reduced, and a required output can be obtained.

  That is, even if the thickness of each magnetic body 45 (permanent magnet)... Is made shorter than the thickness of the stator core 74, the required output can be obtained, so that the output of the electric motor 2 is almost reduced. In addition, the exciting force applied to the teeth of the stator 4 can be dispersed in the direction of the stator 4 width Ho (arrow direction in the figure) wider than the magnetic body 45 width Hmg, and vibration transmission to the shell 1A is vibrated. It can be reduced by the distribution of transmission. The minimum value of Hmg / Ho is set to 0.2 because of the efficiency of the electric motor 1 and the cost of the stator 4.

  The noise waveform of the electric compressor C is shown in FIG. The portion 500 Hz to 10 kHz (audible sound range) indicated by hatching in the figure is lowered. In this figure, SH indicates Ho. From this figure, when the stator 4 width Ho = 40 mm and the magnetic body 45 width Hmg = 40 mm, the conventional large noise, and when the stator 4 width Ho = 50 mm and the magnetic body 45 width Hmg = 40 mm, the noise is greatly reduced and fixed. It can be seen that when the core 4 width Ho = 45 mm and the magnetic body 45 width Hmg = 40 mm, the noise is between the stator 4 width Ho = 50 and 40. In this case as well, the electric compressor C uses twin rotary 700W, the refrigerant uses R401A, the electric motor 2 uses concentrated winding, and a rare earth permanent magnet. Further, Ct / Et = 43 ° C./44° C. is operated at 80 Hz, and the microphone is horizontally installed at a position 1 m apart. The description of FIG. 18 is shown in Table 2, and the noise level is a value when Hmg / Ho is changed.

It can be seen from the above table that the noise is reduced.

  Next, another electric compressor C is shown in FIGS. In this case, the electric compressor C uses the stator 4 provided with the notch 74A of FIG. 1 and the magnetic bodies 45... Inserted into the slots 41, 42, 43, 44 of FIG. The rotor 5 is shorter than the stator core 74 in thickness.

  The magnetic body 45 has a ratio L / D between the diameter D of the rotor core 26 and the dimension L in the direction of the rotation axis 6 smaller than 1.1, and the thickness t of the magnetic body 45 and the product thickness in the direction of the rotation axis. The ratio t / Hmg with Hmg is made smaller than 0.1. That is, the magnetic body 45 is composed of a rare earth magnet material, the diameter of the rotor core 26 of the rotor 5 is D, the dimension of the rotor core 26 in the direction of the rotation axis 6 is L, and the thickness dimension of the magnetic body 45. Where t is the ratio of the dimension L to the dimension D is L / D <1.1, and the ratio of the dimension t to the dimension Hmg is t / Hmg <0.1. The vibration of the shell portion 1A can be reduced by dispersing the vibration of the magnetic material 45, and the ratio t / Hmg of the thickness dimension t of the magnetic body 45 and the product thickness Hmg in the direction of the rotation axis 6 can be made smaller than 0.1. The vibration of the yoke portion of the stator 4 can be dispersed to reduce the vibration of the shell portion. Except for the stator core 74 and the magnetic body 45, the configuration is the same as that shown in FIGS. Thereby, even when the yoke portion of the stator 4 is vibrated, the vibration force to the tooth portion of the stator 5 can be dispersed to greatly reduce the vibration transmission to the shell portion 1A. Therefore, noise generated from a cooling device provided in an air conditioner, a freezer, a refrigerator, a showcase, or the like can be greatly reduced.

It is a vertical side view of the electric compressor of this invention which provided the notch part in the rotating shaft extension direction of the rotor. It is a cross-sectional top view of the electric compressor of FIG. It is a partial vertical side view of the rotor of the present invention. It is a top view of the rotor of the present invention. It is a top view of the iron plate for rotors which comprises the rotor of this invention. It is a side view of the rotor core which comprises the rotor of this invention. It is a perspective view of the magnetic body which comprises the rotor of this invention. It is a figure which shows the demagnetization curve of the permanent magnet used as a magnetic body. It is a figure which shows the waveform of the noise of the electric compressor which provided the notch part in the rotating shaft extension direction of the rotor. It is a vertical side view of another electric compressor. It is a cross-sectional top view of the electric compressor of FIG. It is a vertical side view of another electric compressor. It is a cross-sectional top view of the electric compressor of FIG. It is a vertical side view of another electric compressor. It is a cross-sectional top view of the electric compressor of the same FIG. It is a vertical side view of another electric compressor of the present invention in which a magnetic body provided on a rotor is configured to be shorter than a stator. It is a cross-sectional top view of the electric compressor of FIG. It is a figure which shows the waveform of the noise of the electric compressor which comprised the magnetic body provided in the rotor shorter than a stator. It is a vertical side view of another electric compressor of the present invention in which a notch is provided in the direction of extension of the rotation axis of the rotor and a magnetic body provided on the rotor is configured shorter than the stator. It is a cross-sectional top view of the electric compressor of FIG. It is a vertical side view of the conventional electric compressor. It is a cross-sectional top view of the electric compressor of FIG. It is a refrigerant circuit figure of the cooling device using the electric compressor of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 1A Shell part 2 Electric motor 3 Compression element 4 Stator 5 Rotor 6 Rotating shaft 7 Stator winding 26 Rotor core 45 Magnetic body 68 Compressor 69 Condenser 70 Expansion valve 71 Evaporator 74 Stator core 74A Notch Part C Electric compressor

Claims (2)

In an electric motor that houses an electric element in a container and a compression element driven by a rotating shaft connected to the electric element,
A stator having a stator core fixed to a part of the electric element abutting against an inner wall of the container and spaced apart from the other; and a magnetic body attached to the rotating shaft; And the dimension of the stator core in the direction of the rotation axis of the portion where the stator core contacts the container is H, and the dimension of the stator core in the direction of the rotation axis An electric motor characterized in that H <Ho when H is Ho. In an electric motor that houses an electric element in a container and a compression element driven by a rotating shaft connected to the electric element,
A stator having a stator core fixed to a part of the electric element abutting against an inner wall of the container and spaced apart from the other; and a magnetic body attached to the rotating shaft; And the dimension of the portion of the stator core in contact with the container in the direction of the rotational axis H, and the dimension of the stator core in the direction of the rotational axis. Ho, wherein the dimension of the magnetic material in the direction of the rotation axis is Hmg, H <Ho and Hmg <Ho.