JP2009162168A - Sealed motor compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an oil content of a coolant gas discharged from a hermetic container in a sealed motor compressor. <P>SOLUTION: This sealed motor compressor 50 includes a compression mechanism 2, an electric motor 7, and a hermetic container 1. The electric motor 7 comprises a stator 7 having an iron core 23 and a coil 24, from which end coils 17 project from both sides of the iron core 23, a rotor 7a rotatably arranged in a center hole of the iron core 23, a shaft 6, which is fitted with the center hole of the rotor 7a, at least one of side projects from the rotor 7a, and to which an eccentric force is applied, and an upper balance weight 16a and a lower balance weight 16b arranged on upper and lower sides of the rotor 7a. Outer circumferences at tips of the upper and lower balance weights 16 project further than the upper and lower end coils 17 along the entire circumference. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hermetic electric compressor, and is particularly suitable for a hermetic electric compressor including an electric motor having balance weights installed on both sides of a rotor.

  As a conventional hermetic electric compressor, there is one disclosed in Japanese Patent Application Laid-Open No. 2000-73977 (Patent Document 1).

  The electric motor for a compressor disclosed in Patent Document 1 stores a compression mechanism that compresses refrigerant gas and discharges the refrigerant gas into an airtight container, an electric motor that drives the compression mechanism, a compression mechanism and the electric motor, and stores lubricating oil at the bottom. And a sealed container.

  The compression mechanism includes a fixed scroll in which a spiral wrap is erected on the end plate, and a orbiting scroll in which a spiral wrap is erected on the end plate and meshed with the fixed scroll to form a compression chamber; And a frame that supports the fixed scroll and the orbiting scroll. This compression mechanism compresses the refrigerant gas by the revolving motion of the orbiting scroll in response to the rotational motion of the rotor of the electric motor, but there is a sliding portion between the fixed scroll and the orbiting scroll, and the sliding portion is lubricated. Refrigerator oil is supplied to improve the sealing performance of the compression space. Thereby, refrigeration oil is mixed with refrigerant gas and discharged in the compression process.

  The electric motor is fitted with a stator having an iron core and a coil in which an end coil protrudes from both sides of the iron core, a rotor rotatably arranged in a center hole of the iron core, and a center hole of the rotor And a shaft on which at least one side protrudes from the rotor and an eccentric force is applied by a compression mechanism, and an upper balance weight and a lower balance weight that are installed on the upper and lower sides of the rotor and lower in height than the end coils. Configured.

  The mist-like refrigerant gas containing a large amount of refrigerating machine oil discharged upward from the discharge port of the fixed scroll of the compression mechanism passes through the outer periphery of the compression mechanism and the outer periphery of the motor, and then the stator and the rotor. And flows out from the lower side to the upper side through the discharge pipe to the refrigeration cycle outside the sealed container. At this time, the mass percentage (wt%) of the oil contained in the refrigerant discharged to the refrigeration cycle outside the sealed container is called the oil content (oil rate) in the refrigerant gas.

  And by making the upper end of the upper balance weight a circumferential outer peripheral surface, it is possible to reduce the mist-like refrigerant gas in the space near the discharge pipe above the rotor, and to reduce the fineness of oil droplets contained in the refrigerant gas. By suppressing the refrigeration, the refrigeration oil in the refrigerant gas discharged to the refrigeration cycle is reduced, and the oil rate is reduced.

  In addition, as a modification of the upper balance weight, FIG. 3 of Patent Document 1 illustrates an example in which an opening for discharging the refrigerating machine oil flowing into the upper portion of the rotor is provided in a part of the circumferential outer peripheral surface. .

Japanese Unexamined Patent Publication No. 2000-73977

  However, in the above-described hermetic electric compressor of Patent Document 1, since the upper balance weight and the lower balance weight are lower than the end coil, refrigerant gas is formed on the upper surface of the upper balance weight and the lower surface of the lower balance weight. It was not considered that the oil droplets contained in the refrigerant gas were refined by flowing in and stirring the refrigerant gas on these surfaces of the upper and lower balance weights.

  An object of the present invention is to provide a hermetic electric compressor that can reduce the oil content of refrigerant gas discharged from a hermetic container.

  Other objects and advantages of the present invention will become apparent from the following description.

  In order to achieve the above object, a first aspect of the present invention includes a compression mechanism that compresses refrigerant gas and discharges the refrigerant gas into a sealed container, an electric motor that drives the compression mechanism, and the compression mechanism and the electric motor. And the sealed container for storing lubricating oil at the bottom, and the electric motor includes a stator having an iron core and coils from which end coils protrude from both sides of the iron core, and the iron core. A rotor rotatably disposed in a central hole; a shaft that is fitted in the central hole of the rotor and that protrudes from the rotor and is engaged with the compression mechanism to apply an eccentric force; and the rotation A hermetic electric compressor including a balance weight installed on both sides of the child, wherein refrigerant gas containing oil discharged from the compression mechanism flows from one side to the other between the stator and the rotor In both sides Tip outer peripheral surface of the lance weight is that protrudes than the either of the end coil over the entire circumference.

A more preferable specific configuration example in the first aspect of the present invention is as follows.
(1) The gas passage area between the outer peripheral surface protruding from the end coil of the balance weight on the one side and the inner peripheral surface of the sealed container, and protruding from the end coil of the balance weight on the other side The gas passage area between the outer peripheral surface and the inner peripheral surface of the sealed container is made equal or less.
(2) The ratio of the gas passage area on the one side and the gas passage area on the other side is in the range of 0.9 to 1.0.

Further, the second aspect of the present invention is a compression mechanism for compressing the refrigerant gas and discharging it into the sealed container;
An electric motor that drives the compression mechanism; and a hermetic container that stores the compression mechanism and the electric motor in a vertical position and stores lubricating oil at the bottom, and the compression mechanism has a spiral shape on the end plate. A fixed scroll having a wrap standing, a orbiting scroll that has a spiral wrap standing on an end plate and meshes with the fixed scroll to form a compression chamber, and a frame that supports the fixed scroll and the orbiting scroll The electric motor includes a stator having an iron core and a coil from which an end coil protrudes from both sides of the iron core, a rotor rotatably disposed in a center hole of the iron core, and the rotor A shaft that is fitted in the central hole of the rotor and protrudes from the rotor so that an eccentric force is applied by the compression mechanism, an upper balance weight installed on the upper side and the lower side of the rotor, and A balance gas, and refrigerant gas containing oil discharged from the compression mechanism passes between the outer periphery of the compression mechanism and the outer periphery of the electric motor, and then the space between the stator and the rotor from the lower side. In the hermetic electric compressor that flows upward, the outer peripheral surface of the tip portion of the upper balance weight protrudes upward from the upper end coil over the entire circumference and approaches the frame, and the outer peripheral surface of the tip portion of the lower balance weight It exists in protruding below the said lower end coil over the perimeter, and being in the oil level of the said lubricating oil.

A more preferable specific configuration example in the second aspect of the present invention is as follows.
(1) The area of the gas passage between the outer peripheral surface of the lower balance weight projecting from the end coil and the inner peripheral surface of the sealed container, the outer peripheral surface of the upper balance weight projecting from the end coil, and the The ratio of the area of the gas passage to the inner peripheral surface of the sealed container should be equal or less.
(2) In (1), the ratio of the lower gas passage area to the lower gas passage area is in the range of 0.9 to 1.0.
(3) The upper and lower balance weights are formed so that the outer peripheral surface of the balance weight is symmetrical when the rotation center axis is the axis of symmetry.
(4) The upper balance weight has an upper unbalance amount imparting recess that is recessed from the counter-rotor side.
(5) The upper and lower balance weights are made of a metal integrated molded product.
(6) The upper and lower balance weights are fixed to the rotor via a common rivet.

  According to the sealed electric compressor of the present invention, the oil content of the refrigerant gas discharged from the sealed container can be reduced.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 11C.

  The overall configuration, operation, function, and the like of the hermetic electric compressor 50 in the present embodiment will be described with reference to FIGS. 1 to 3. In FIG. 2, the solid arrow indicates the flow of the lubricating oil 8 sucked up from the oil reservoir 9 at the bottom of the closed container 1, and the dotted arrow indicates the flow of the refrigerant gas discharged from the compression mechanism 2.

  The hermetic type electric compressor 50 is used as a refrigeration cycle component device such as a refrigeration air conditioner (for example, an air conditioner, a refrigerator, a freezer, a refrigeration / refrigeration showcase, etc.), a heat pump hot water supply device, etc. The mechanism 2 and the electric motor 7 are provided as main components.

  The sealed container 1 includes a cylindrical tube portion and a lid portion welded to the top and bottom of the tube portion, and the inside is a sealed space. The hermetic container 1 houses the compression mechanism 2 and the electric motor 7 and stores a lubricating oil 8 such as a refrigerating machine oil in an oil reservoir 9 at the bottom. The oil surface of the lubricating oil 8 is set to be positioned above the auxiliary bearing 15.

  A suction pipe 11 is provided through the upper lid portion of the sealed container 1, and a discharge pipe 22 is provided through the cylinder portion of the sealed container 1. The discharge pipe 22 is located immediately below the frame 5 and is provided so as to protrude in the center direction in the sealed container 1. The distal end of the discharge pipe 22 projects from the outer peripheral surface of the end coil 17 toward the center and is opened.

  The compression mechanism 2 compresses a refrigerant gas such as fluorocarbon and carbon dioxide and discharges the refrigerant gas into the sealed container 1, and is installed in the upper part of the sealed container 1. The compression mechanism 2 includes a fixed scroll 3, a turning scroll 4, a frame 5, and an Oldham ring 10 as main components.

  The fixed scroll 3 is configured by standing a spiral wrap on the end plate, and is bolted on the frame 5. A suction port 12 is provided in the peripheral portion of the fixed scroll 3, and a discharge port 14 is provided in the central portion. A suction pipe 11 communicates with the suction port 12. The discharge port 14 communicates with the space above the compression mechanism 2 in the sealed container 1.

  The orbiting scroll 4 is configured by standing a spiral wrap on the end plate, and meshes with the fixed scroll 3 to form a compression chamber. The orbiting scroll 4 is sandwiched between the fixed scroll 3 and the frame 5. A boss portion protrudes from the anti-fixed scroll side of the orbiting scroll 4, and an orbiting bearing is installed in the boss portion, and an eccentric pin portion 6a of the shaft 6 is fitted in the orbiting bearing.

  The Oldham ring 10 constitutes a rotation restricting mechanism of the orbiting scroll 4 and is installed between the orbiting scroll 4 and the frame 5 to prevent the orbiting scroll 4 from rotating and to perform a circular orbit motion.

  The frame 5 is fixed to the sealed container 1 by welding, and supports the fixed scroll 3, the Oldham ring 10, and the orbiting scroll 4. A cylindrical portion protruding downward is provided at the center of the frame 5. A main bearing 5a that supports the shaft 6 is provided in the cylindrical portion.

  A plurality of discharge gas passages 18 a communicating the upper space of the fixed scroll 3 and the lower space of the frame 5 are formed in the outer peripheral portions of the fixed scroll 3 and the frame 5. The plurality of discharge gas passages 18a are arranged over the entire circumference.

  The electric motor 7 includes a stator 7b, a rotor 7a, a shaft 6, and a balance weight 16 as main components, and is configured as a synchronous motor including a permanent magnet 35 (see FIG. 5b) on the rotor 7a.

  The stator 7b includes, as main components, a coil 24 having a plurality of conductors that generate a rotating magnetic field by flowing an electric current, and an iron core 23 for efficiently transmitting the rotating magnetic field. The end coil 17 of the coil 24 protrudes from both sides of the iron core 23. The iron core 23 is fixed by being shrink-fitted in the sealed container 1. A large number of notches are formed on the outer periphery of the stator 7b, and a discharge gas passage 18 is formed between the notches and the sealed container 1.

  The rotor 7 a includes an iron core 25 and a permanent magnet 35 incorporated in the iron core 25 as main components, converts a rotating magnetic field from the stator 7 b into a rotational motion, and is rotated around the shaft 6. . The rotor 7a is rotatably disposed in the central hole of the iron core 23 of the stator 7b.

  The shaft 6 is fitted into the central hole of the rotor 7a and integrated with the rotor 7a. One side (upper side in the illustrated example) of the shaft 6 protrudes from the rotor 7 a and is engaged with the compression mechanism 2, and an eccentric force is applied by the compression operation of the compression mechanism 2. In the present embodiment, the shaft 6 protrudes from both sides of the rotor 7a, and is supported by the main bearing 5a and the auxiliary bearing 15 on both sides of the rotor 7a, and can rotate stably. The auxiliary bearing 15 is supported by a supporting member fixed by welding to the sealed container 1 and is immersed in the lubricating oil 8.

  The lower end of the shaft 6 extends into the oil reservoir 9 at the bottom of the sealed container 1. The shaft 6 is provided with through holes 6b for supplying the lubricating oil 8 to the bearings and the sliding surfaces, and the lubricating oil 8 is sucked up from the oil reservoir 9 through the through holes 6b. The lubricating oil 8 sucked up through the shaft through hole 6 b is supplied to the sliding portions of the bearings and the compression mechanism 2. Since the lubricating oil 8 supplied to the sliding portion of the compression mechanism 2 is discharged from the discharge port 14 at the center of the fixed scroll 3 together with the refrigerant gas, the discharge gas discharged from the discharge port 14 has a mist shape. Contains a lot of lubricating oil.

  The balance weight 16 includes an upper balance weight (compression mechanism side balance weight) 16a and a lower balance weight (anti-compression mechanism side balance weight) 16b installed on both sides of the rotor 7a, and a plurality of rivets 31 are shared. It is fixed to the rotor 7a. The upper and lower balance weights 16 a and 16 b are fixed to the rotor 7 a via a common rivet 31. Accordingly, the upper and lower balance weights 16a and 16b can be fixed to the rotor 7a at low cost and easily.

  The outer peripheral surfaces of the upper balance weight 16a and the lower balance weight 16b are formed symmetrically with the rotation center axis as the symmetry axis. The outer peripheral surfaces of the tip portions of the upper balance weight 16a and the lower balance weight 16b protrude from the upper end coil (compression mechanism side end coil) 17a and the lower end coil (anti-compression mechanism side end coil) 17b over the entire circumference.

  The outer peripheral surface of the front end portion of the upper balance weight 16a protrudes upward from the upper end coil 17a over the entire circumference and approaches the frame 5, and the outer peripheral surface of the front end portion of the lower balance weight 16b extends below the lower end coil 17b over the entire periphery. And is approaching the oil level of the lubricating oil 8.

  The gas passage area B between the outer peripheral surface of the lower balance weight 16b protruding from the end coil 17 and the inner peripheral surface of the sealed container 1, the outer peripheral surface of the upper balance weight 16a protruding from the end coil 17, and the sealed container 1 The ratio with respect to the gas passage area A between the inner peripheral surface and the inner peripheral surface is made equal or less. Specifically, the ratio of the lower gas passage area to the lower gas passage area is set to be in the range of 0.9 to 1.0.

  In such a configuration, when the electric motor 7 is energized and the rotor 7a is rotated, the shaft 6 is also rotated accordingly, and the eccentric pin portion 6a performs an eccentric rotational movement, whereby the orbiting scroll 4 is driven to rotate. The compression chamber formed between the fixed scroll 3 and the orbiting scroll 4 becomes smaller while moving from the outer peripheral side to the central portion. As a result, the refrigerant gas is sucked and compressed through the suction pipe 11 and the suction port 12 leading to the refrigeration cycle outside the sealed container 1, and the compressed refrigerant gas is discharged from the discharge port 14 at the center of the fixed scroll 3. It is discharged into the upper space in the sealed container 1. These operations are repeated.

  A mist-like refrigerant gas containing a large amount of lubricating oil discharged upward from the discharge port 14 of the fixed scroll 3 passes through a discharge gas passage 18 a provided in the outer peripheral portion of the compression mechanism 2 and is located inside the sealed container 1. It is guided from the entire circumference to a space below the compression mechanism 2 (a space above the electric motor 7). In this process, a part of the oil contained in the refrigerant gas is separated, travels through the discharge gas passage 18a, the inner surface of the sealed container 1, and the like, and is finally stored in the oil reservoir 9 at the bottom of the sealed container 1.

  Here, since the outer peripheral surface of the tip end portion of the upper balance weight 16a protrudes upward from the upper end coil 17a over the entire circumference, the refrigerant gas guided to the space below the compression mechanism 2 is the upper surface of the upper balance weight 16a. And it is suppressed that it flows in into the upper part. As a result, the refrigerant gas is prevented from being stirred on the upper surface of the upper balance weight 16a, the refinement of oil droplets contained in the refrigerant gas is suppressed, and the refrigerant gas moves above the upper surface of the upper balance weight 16a. Passing directly to the discharge pipe 22 and flowing out to the refrigeration cycle is suppressed. In particular, in the present embodiment, since the outer peripheral surface of the front end portion of the upper balance weight 16a is approached to the frame 5 over the entire circumference, these oil outflow suppression effects can be significantly improved.

  In this way, most of the refrigerant gas introduced into the space below the compression mechanism 2 passes through the discharge gas passage 18b provided in the outer peripheral portion of the electric motor 7 from the entire periphery to the space below the electric motor 7 (lubricating oil). 8 space above the oil level). In this process, a part of the oil contained in the refrigerant gas is further separated and is stored in the oil reservoir 9 at the bottom of the sealed container 1 through the discharge gas passage 18b, the inner surface of the sealed container 1, and the like.

  Here, since the outer peripheral surface of the tip end portion of the lower balance weight 16b protrudes downward from the lower end coil 17b over the entire circumference, the refrigerant gas introduced into the space 21 below the electric motor 7 is transferred to the lower balance weight 16b. Inflow to the lower surface and the lower side thereof is suppressed, and the flow direction is reversed by the outer peripheral surface of the tip of the lower balance weight 16b, and the flow direction flows into the space between the lower balance weight 16b and the lower end coil 17b. Is inverted. As a result, the refrigerant gas is prevented from being stirred on the lower surface of the lower balance weight 16b, the refinement of oil droplets contained in the refrigerant gas is suppressed, and the refrigerant gas is reversed after being discharged from the discharge gas passage 18b. In the process, part of the oil contained in the refrigerant gas is further separated. In particular, in the present embodiment, since the outer peripheral surface of the front end portion of the lower balance weight 16b is close to the oil surface of the lubricating oil 8 over the entire periphery, the oil content outflow suppressing effect can be significantly improved.

  The refrigerant gas in which the flow direction is reversed is the space between the lower balance weight 16b and the lower end coil 17b, the gap 19 between the rotor 7a and the stator 7b, the upper balance weight 16a and the upper end coil 17a. The air is sucked into the discharge pipe 22 through the space 20 and the space 20 above the upper end coil 17a, and flows out into the refrigeration cycle. Here, since the outer peripheral surface of the tip end portion of the upper balance weight 16a protrudes upward from the upper end coil 17a over the entire circumference, the refrigerant gas introduced into the space above the upper end coil 17a is in the upper balance weight 16a. Inflow to the upper surface and above is suppressed. As a result, the refrigerant gas is suppressed from being stirred on the upper surface of the upper balance weight 16a, and the refinement of oil droplets contained in the refrigerant gas is suppressed.

  In the present embodiment, the upper balance weight 16 a protruding from the gas passage area B of the space 20 between the outer peripheral surface protruding from the end coil 17 of the lower balance weight 16 b and the inner peripheral surface of the sealed container 1 and the end coil 17. Since the gas passage area A of the space 21 between the outer peripheral surface of the airtight container 1 and the inner peripheral surface of the sealed container 1 is equal to or less than that, the oil content can be significantly reduced.

  Such a reduction effect will be described with reference to FIG. 3 showing the relationship between the gas passage area ratio B / A, which is the ratio of the gas passage area B and the gas passage area A, and the oil content.

For refrigerant gas flowing from above the motor 7 through the gap between the rotor 7a and the stator 7b to above the motor 7, the difference in gas passage area due to the difference in shape between the upper side and the lower side of the motor 7 It is necessary to consider the influence of the refrigerant gas flow that occurs between the upper and lower sides of the electric motor 7 due to the above. In particular, when the gas flow between the upper and lower motor 7 is regarded as a steady stream to be treated by hydrodynamic applying the energy conservation law, that the relation holds called Bernoulli's principle, which is mathematically expressed by ^{ρv 2/2 + p + ρgz} = const Are known.

  According to the above relational expression, when the gas passage area B is larger than the gas passage area A, the flow velocity in the gas passage area B decreases and the pressure increases, and the flow velocity in the upper gas passage area relatively increases. Since the pressure decreases, a flow from the lower side to the upper side due to the pressure difference is generated, which acts in a direction that prevents oil separation in the lower space. For this reason, when the gas passage area ratio B / A exceeds 1.0, the oil content increases rapidly as shown in FIG.

  According to the above-described embodiment, the oil content of the discharge gas can be reduced only by changing the balance weights 16a and 16b of the rotor 7a of the electric motor 7, and the compression mechanism 2 and the auxiliary bearing member can be reduced. Since 15 can be designed in the conventional manner, an increase in cost due to the change can be suppressed. As a result, the gas-liquid separation between the refrigerant gas and the lubricating oil can be performed at low cost, and the oil content of the discharge gas can be suppressed. Therefore, it is possible to expect an effect of preventing a pipe pressure loss in the refrigeration cycle and a decrease in heat exchange efficiency in a heat exchanger such as a condenser and an evaporator, and the cycle performance can be greatly improved. Further, since oil take-out in the compressor can be suppressed, the oil level can be stabilized, and stable oil supply to the bearing portion can be achieved, so that an improvement in reliability can be expected.

  Next, the electric motor 7 will be specifically described with reference to FIGS. 4A to 11C.

  Lubricating oil 8 that lubricates the bearing, lubricating oil 8 separated from the refrigerant gas discharged from the compression mechanism 2, and the like flow into the upper surface of the rotor 7 a. As shown in FIGS. 4A to 4C, there is provided an oil outflow hole 26 that guides the lubricating oil 8 flowing into the upper surface of the rotor 7a through the rotor 7a and the lower balance weight 16b and below the lower balance weight 16b. By flowing out the lubricating oil 8 through the oil outflow hole 26, it is necessary to open an opening for releasing the lubricating oil 8 flowing into the upper surface of the rotor 7a on the outer peripheral surface of the upper balance weight 16a as in the conventional example. In addition, it is possible to prevent the oil droplets contained in the refrigerant gas from being refined by stirring the refrigerant gas through the opening.

  The oil outflow hole 26 includes a first oil outflow hole 26a formed through the rotor 7a from the upper surface to the lower surface, and a second oil outflow hole 26b formed through the upper surface of the lower balance weight 16b from the lower surface. It is composed of As a result, the lubricating oil 8 flowing into the upper surface of the rotor 7a flows down to the lower surface of the rotor 7a through the first oil outflow hole 26a, and further flows down the side wall surface of the second outflow hole 26b, and then the second outflow. The oil can be reliably dripped into the oil reservoir 9 adjacent to the hole 26b.

  The first oil outflow holes 26a are constituted by a plurality of thin holes, and are arranged circumferentially around the central hole of the rotor 7a. The lower balance weight 16b has a central hole 26b through which the shaft 6 passes, and this central hole 26b is formed larger than the circumferential diameter of the arrangement of the plurality of first oil outflow holes 26a and also serves as the second oil outflow hole 26b. ing. Accordingly, the lubricating oil 8 flowing into the upper surface of the rotor 7a can be reliably dropped into the oil reservoir 9 through any one of the plurality of first oil outflow holes 26a with a simple configuration even when the compressor is slightly inclined. it can.

  The lower balance weight 16b is provided with a plurality of rivet recesses 26c communicating with the center hole 26b at the lower periphery of the center hole 26b and opened on the lower surface at equal intervals, and penetrates from the bottom surface of the plurality of rivet recesses 26c. It is fixed by a rivet 31. As a result, the lubricating oil 8 flowing down the central hole 26b is collected in the rivet recesses 26c, and flows down the wall surfaces of the rivet recesses 26c. While being dripped, the length of the rivet 31 can be shortened and the reliability can be improved.

  The upper balance weight 16a has a central hole 37 through which the shaft 6 passes. The central hole 37 is formed larger than the circumferential diameter of the arrangement of the plurality of first oil outflow holes 26a. As a result, even when there is a large amount of lubricating oil 8 that has lubricated the bearings or separated from the refrigerant gas discharged from the compression mechanism 2, the lubricating oil 8 is temporarily stored in the central hole 37. However, it is possible to reliably flow out through the plurality of first oil outflow holes 26a.

  The lower balance weight 16b is adjacent to the central hole 26b via the partition wall 32, and is provided with a lower unbalance amount imparting recess 33 recessed from the rotor 7a side, and a third penetrating from the bottom of the upper unbalance imparting recess 33 to the lower surface. An oil outflow hole 26d is formed. Since the lubricating oil 8 that has traveled along the lower surface of the rotor 7a and flows into the lower unbalance amount imparting recess 33 flows out immediately from the third oil outflow hole 26d, the unbalance amount of the lower balance weight 16b is reduced to the lower unbalance amount imparted recess. It is possible to prevent the lubricant oil 8 that has flowed into 33 from changing.

  The rotor 7a includes permanent magnets 35 inserted into a plurality of magnet insertion holes 34, and the permanent magnets 35 are arranged so as to form a quadrangle when viewed from above. And the partition wall 32 of the lower balance weight 16b is provided so that the lower surface of the magnet insertion hole 34 may be plugged up. Thereby, it is possible to achieve both the application of the lower unbalance amount and the support of the permanent magnet 35 with a simple configuration.

  Specifically, the permanent magnet 35 is composed of a plurality of pieces (three in the illustrated example), the central permanent magnet 35 is supported by the partition wall 32, and the permanent magnets 35 on both sides are the main body portions of the lower balance weight 16b. It is supported by. Thus, the following effect is acquired by dividing | segmenting the permanent magnet 35 into several pieces. First, the cost of a single permanent magnet can be reduced. Second, an eddy current is generated in the permanent magnet 35 due to the influence of the magnetic field from the stator 7b, but the eddy current loss can be reduced by dividing the permanent magnet 35.

  The upper balance weight 16a communicates with the central hole 37, is provided with an upper unbalance amount imparting recess 36 that opens to the upper surface, and is fixed via a rivet 31 that penetrates from the bottom surface of the upper unbalance amount imparting recess 36. . Thereby, the length of the rivet 31 can be shortened, and the reliability can be improved.

  As described above, the upper balance weight 16a, the rotor 7a, and the lower balance weight 16b are configured such that the upper and lower portions communicate with each other through the center hole 37, the oil outflow hole 26a, and the center hole 26b.

  The coil 24 of the stator 7b is wound by a concentrated winding method. Accordingly, the height of the coil end 17 can be reduced, in other words, the balance weight 16 can be easily protruded from the end coil 17.

  The upper and lower balance weights 16 are formed of a metal integral molded product, specifically, a zinc alloy die cast integral molded product, so that the outer peripheral surface of the balance weight 16 is symmetrical when the rotation center axis is the symmetry axis. Yes. Thus, the upper and lower balance weights 16 can be easily manufactured.

1 is a longitudinal sectional view of a hermetic electric compressor according to an embodiment of the present invention. It is a figure which shows the flow of the refrigerant gas and lubricating oil in the hermetic electric compressor of FIG. It is the characteristic view which calculated | required experimentally the relationship between the gas passage area ratio B / A and oil content rate in a sealed electric compressor. It is a top view of the electric motor of this embodiment. It is AA sectional drawing of FIG. 4A. FIG. 4B is a bottom view of FIG. 4A. It is a top view of the state which installed the balance weight in the rotor in the electric motor of this embodiment. It is BB sectional drawing of FIG. 5A. It is a bottom view of Drawing 5A. It is the perspective view seen from the state which installed the balance weight in the rotor in the electric motor of this embodiment. It is the perspective view seen from the state which installed the balance weight in the rotor in the electric motor of this embodiment. It is a partial cross section enlarged view of FIG. It is a top view of the rotor in this embodiment. It is CC sectional drawing of FIG. 9A. It is a top view of the upper balance weight in this embodiment. It is DD sectional drawing of FIG. 10A. FIG. 10B is a bottom view of FIG. 10A. It is a top view of the lower balance weight in this embodiment. It is EE sectional drawing of FIG. 11A. FIG. 11B is a bottom view of FIG. 11A.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Airtight container, 2 ... Compression mechanism, 3 ... Fixed scroll, 4 ... Orbiting scroll, 5 ... Frame, 5a ... Main bearing, 6 ... Shaft, 6a ... Eccentric pin part, 6b ... Oil supply hole, 7 ... Electric motor, 7a DESCRIPTION OF SYMBOLS ... Rotor, 7b ... Stator, 8 ... Lubricating oil, 9 ... Oil reservoir, 10 ... Oldham ring, 11 ... Suction pipe, 12 ... Suction port, 14 ... Discharge pipe, 15 ... Sub bearing, 16a ... Upper balance weight, 16b ... Lower balance weight, 17 ... Coil end, 17a ... Upper coil end, 17b ... Lower coil end, 18a, 18b ... Discharge gas passage, 19 ... Air gap between stator and rotor, 20 ... Upper space of motor 21 ... Lower space of the motor, 22 ... Discharge pipe, 23 ... Stator iron core, 24 ... Stator coil, 25 ... Rotor iron core, 26 ... Oil outflow hole, 26a ... First oil outflow hole, 26b ... second oil outflow hole Center hole of lower balance weight), 26c ... recess for rivet, 26d ... third oil outflow hole, 31 ... rivet, 32 ... partition wall, 33 ... lower unbalance amount imparting recess, 35 ... permanent magnet, 36 ... upper unbalance An amount imparting recess, 37... Center hole of upper balance weight, 50.

Claims (10)

A compression mechanism that compresses the refrigerant gas and discharges it into the sealed container;
An electric motor that drives the compression mechanism;
The compressed container and the electric motor are housed and the sealed container that stores lubricating oil at the bottom is configured,
The electric motor includes a stator having an iron core and a coil from which an end coil protrudes from both sides of the iron core, a rotor rotatably disposed in a center hole of the iron core, and a center hole of the rotor. A shaft that is fitted and at least one side protrudes from the rotor and is engaged with the compression mechanism to apply an eccentric force, and balance weights installed on both sides of the rotor,
In a hermetic electric compressor in which a refrigerant gas containing oil discharged from the compression mechanism flows from one side to the other between the stator and the rotor,
The hermetic electric compressor characterized in that the outer peripheral surfaces of the front ends of the balance weights on both sides protrude from the end coils on both sides over the entire circumference.   2. The gas passage area between the outer peripheral surface protruding from the end coil of the balance weight on the one side and the inner peripheral surface of the closed container, and the end coil of the balance weight on the other side according to claim 1. The hermetic electric compressor characterized in that the gas passage area between the projecting outer peripheral surface and the inner peripheral surface of the sealed container is made equal or less.   3. The hermetic electric compressor according to claim 2, wherein a ratio of the gas passage area on the one side to the gas passage area on the other side is in a range of 0.9 to 1.0. A compression mechanism that compresses the refrigerant gas and discharges it into the sealed container;
An electric motor that drives the compression mechanism;
A hermetic container that stores the compression mechanism and the electric motor in an up-and-down position and stores lubricating oil at the bottom, and
The compression mechanism includes a fixed scroll in which a spiral wrap is erected on an end plate, and a orbiting scroll in which a spiral wrap is erected on the end plate and meshed with the fixed scroll to form a compression chamber; A frame that supports the fixed scroll and the orbiting scroll,
The electric motor includes a stator having an iron core and a coil from which an end coil protrudes from both sides of the iron core, a rotor rotatably disposed in a center hole of the iron core, and a center hole of the rotor. A shaft to which at least one side protrudes from the rotor and an eccentric force is applied by the compression mechanism; and an upper balance weight and a lower balance weight installed on the upper and lower sides of the rotor,
Sealed electric compression in which refrigerant gas containing oil discharged from the compression mechanism flows from the lower side to the upper side between the stator and the rotor after passing through the outer peripheral portion of the compression mechanism and the outer peripheral portion of the electric motor In the machine
The outer peripheral surface of the tip of the upper balance weight protrudes upward from the upper end coil over the entire circumference and approaches the frame,
A hermetic electric compressor, wherein an outer peripheral surface of a tip portion of the lower balance weight protrudes downward from the lower end coil over the entire circumference and approaches the oil surface of the lubricating oil.   5. The gas passage area between the outer peripheral surface of the lower balance weight projecting from the end coil and the inner peripheral surface of the closed container, and the outer peripheral surface of the upper balance weight projecting from the end coil. The ratio of the area of the gas passage between the airtight container and the inner peripheral surface of the airtight container is made equal to or less than that of the airtight compressor.   6. The hermetic electric compressor according to claim 5, wherein a ratio of the lower gas passage area to the lower gas passage area is in a range of 0.9 to 1.0.   5. The hermetic electric compressor according to claim 4, wherein the upper and lower balance weights are formed symmetrically on the outer peripheral surface of the balance weight when the rotation center axis is a symmetric axis.   5. The hermetic electric compressor according to claim 4, wherein the upper balance weight has an upper unbalance amount imparting recess that is recessed from the counter-rotor side.   5. The hermetic electric compressor according to claim 4, wherein the upper and lower balance weights are formed of a metal integral molded product.   5. The hermetic electric compressor according to claim 4, wherein the upper and lower balance weights are fixed to the rotor via a common rivet.

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