JP2016031024A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hermetic electric compressor capable of reducing an oil content of refrigerant discharged from a hermetic vessel, with a simple configuration.SOLUTION: A compressor comprises: a hermetic vessel 1; a compression mechanism portion 2 that includes a fixed scroll 4, an orbiting scroll 3, the orbiting scroll 3 and the fixed scroll 4 forming a compression chamber 9, and a discharge port 4c discharging refrigerant compressed in the compression chamber 9 to a discharge pressure space within the hermetic vessel 1; an electric motor portion 7 including a rotor 15 and a stator 16 and driving the compression mechanism portion 2; a crankshaft 5 transmitting a rotational force of the rotor 15 to the orbiting scroll 3; an oil reservoir 12 provided in a bottom of the hermetic vessel 1 for storing lubricating oil; and a balance weight located between the compression mechanism portion 2 and the rotor 15, and including an internal space 30 provided in the crankshaft 5 and including a weight portion 15e filled with metal and a cavity, the balance weight including a through-hole 25 penetrating the balance weight radially outward from the internal space 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a compressor.

  The compressor of Patent Document 1 is a compression mechanism that drives a compression mechanism part and a compression mechanism part provided below the compression mechanism part in a hermetic container, and a rotational force of the motor part. A crankshaft for transmitting to the section. Furthermore, an oil supply mechanism is provided that supplies oil in an oil reservoir provided at a lower portion in the sealed container to a bearing portion of the crankshaft and a sliding portion of the compression mechanism portion through a through hole provided in the crankshaft.

  Oil is supplied to the sliding portion of the bearing portion and the compression mechanism portion by the oil supply mechanism to ensure smooth operation of the sliding portion. In addition, the refrigerant compressed by the compression mechanism part flows into the upper space of the oil storage part provided in the lower part of the motor part through the flow path between the sealed container and the motor part, and rotates with the stator of the motor part. The air is discharged from the discharge pipe to the outside of the hermetic container through an air gap between the children and a through hole provided in the axial direction inside the rotor. At this time, the oil supplied to the sliding portion of the bearing portion and the compression mechanism portion moves downward due to gravity and the flow of the refrigerant and is collected in the oil sump. However, the refrigerant always comes into contact with oil, and is stirred inside the sealed container as the rotor fixed to the crankshaft rotates, so that the refrigerant contains refined oil. When refrigerant is discharged from an airtight container, oil is brought into the refrigeration cycle, resulting in increased pipe pressure loss in the refrigeration cycle and reduced heat exchange efficiency in heat exchangers such as condensers and evaporators. Give rise to

  In Patent Document 1, in the hermetic electric compressor, the outer peripheral surface of the tip end portion of the balance weight installed on both sides of the rotor protrudes over the entire circumference from both end coils of the stator of the electric motor unit that drives the compression mechanism unit. To do. With such a structure, the amount of oil discharged from the sealed container to the refrigeration cycle is reduced by suppressing the stirring action accompanying the rotation of the rotor.

  On the other hand, in the hermetic electric compressor of Patent Document 2, an oil separation block is attached to the upper end surface of the rotor of the motor unit that drives the compression mechanism unit, and the oil particles and the refrigerant that have risen from the lower part of the hermetic container to the oil separation block Guide holes into which the mixture with the gas flows are provided. With such a structure, the oil and refrigerant mixture refined by the stirring of the rotor is collided with the end coil protruding from the stator, and the oil and refrigerant gas are separated.

JP 2009-162168 A JP 2005-120835 A

  However, the hermetic electric compressor of Patent Document 1 has an effect of reducing the amount of oil discharged from the hermetic container to the refrigeration cycle by suppressing the stirring action associated with the rotation of the rotor, but the balance weight is cylindrical. Therefore, oil that falls from the bearing section through the crankshaft after lubrication of the bearing section and oil that has risen through the passage that penetrates the rotor in the axial direction accumulates in the balance weight and blows up to the discharge pipe side. As a result, the content of oil contained in the refrigerant discharged from the sealed container is increased.

  Further, in the hermetic electric compressor of Patent Document 2, the guide part for discharging the oil rising from the lower part of the hermetic container through the flow path penetrating the inside of the rotor in the axial direction includes an oil separation plate, a spacer, Since it consists of a plurality of members such as a separation block, the number of parts increases and the number of work steps during assembly increases, which increases costs.

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

  The compressor of the present invention includes a sealed container, a fixed scroll, a turning scroll that forms a compression chamber with a fixed scroll, and a discharge port that discharges the refrigerant compressed in the compression chamber into a discharge pressure space in the sealed container, A compressor mechanism having a rotor and a stator, an electric motor that drives the compressor mechanism, a crankshaft that transmits the rotational force of the rotor to the orbiting scroll, and lubricating oil stored in the bottom of the sealed container An oil reservoir, a suction port for introducing the refrigerant into the sealed container, a discharge port for discharging the refrigerant compressed in the compression chamber to the outside of the sealed container, and a crankshaft located between the compression mechanism and the rotor A balance weight provided with a weight portion filled with metal and an internal space having an air gap, and the balance weight has a through-hole penetrating the balance weight radially outward from the internal space. .

  ADVANTAGE OF THE INVENTION According to this invention, the hermetic type electric compressor which reduced the oil content rate of the refrigerant | coolant discharged from a hermetic container with a simple structure can be provided.

Vertical sectional view of a typical hermetic electric compressor in Example 1 The figure which shows the flow of the refrigerant | coolant and lubricating oil in the hermetic electric compressor of FIG. The perspective view of the rotor in Example 1 of this invention Sectional drawing which looked at the compression mechanism part in the hermetic type electric compressor of Drawing 1 from the bottom Sectional view of the motor part of the hermetic electric compressor of FIG. 1 as seen from below The perspective view of the rotor in Example 2 The top view which expanded and showed the protrusion 40 of the rotor in Example 2. FIG. The perspective view of the rotor in Example 3 The top view which expanded and showed the protrusion 41 of the rotor in Example 3. FIG.

  The compressor of the present invention includes a sealed container, a fixed scroll, a turning scroll that forms a compression chamber with a fixed scroll, and a discharge port that discharges the refrigerant compressed in the compression chamber into a discharge pressure space in the sealed container, A compressor mechanism having a rotor and a stator, an electric motor that drives the compressor mechanism, a crankshaft that transmits the rotational force of the rotor to the orbiting scroll, and lubricating oil stored in the bottom of the sealed container An oil reservoir, a suction port for introducing the refrigerant into the sealed container, a discharge port for discharging the refrigerant compressed in the compression chamber to the outside of the sealed container, and a crankshaft located between the compression mechanism and the rotor A balance weight provided with a weight portion filled with metal and an internal space having an air gap, and the balance weight has a through-hole penetrating the balance weight radially outward from the internal space. . By rotating the rotor, the oil / refrigerant mixture is discharged from the balance weight through the through-hole and collides with the end coil, etc., and the oil / refrigerant gas is blown up in the space near the discharge pipe. Can be separated. Therefore, the oil content of the refrigerant discharged from the sealed container can be reduced with a simple structure.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In the scroll compressor shown in FIG. 1, a compression mechanism unit 2 and an electric motor unit 7 are connected and stored in a sealed container 1 via a crankshaft 5. The compression mechanism unit 2 has a compression chamber 9 formed by meshing the spiral wrap 4a of the fixed scroll 4 and the spiral wrap 3a of the orbiting scroll 3 with each other, and further prevents the orbiting scroll 3 from rotating. An Oldham ring 8 which is a rotation preventing member for making a turning motion, and a frame 6 having a bearing which is coupled to the fixed scroll 4 and supports the rotation of the crankshaft 5 are configured. The electric motor unit 7 includes a rotor 15 and a stator 16. An upper balance weight 15a and a lower balance weight 15b are fastened to the rotor 15 in order to maintain a rotational balance with the compression mechanism. In addition, lubricating oil 13 such as refrigerating machine oil is stored in an oil reservoir 12 at the bottom of the sealed container 1. The airtight container 1 is provided with a suction pipe 14 penetrating the lid 11, and further provided with a discharge pipe 17 penetrating the cylindrical portion of the airtight container 1. The discharge pipe 17 communicates with a discharge hole that is provided directly below the frame 6 toward the center in the sealed container 1.

  Next, the compression action of the scroll compressor will be described. The rotor 15 is given a rotational force by a rotating magnetic field generated by the stator 16. The crankshaft 5 fixed to the rotor 15 rotates as the rotor 15 rotates, and the orbiting scroll 3 rotates eccentrically (revolves) without rotating due to the action of the Oldham ring ring 8. Due to the eccentric rotation of the orbiting scroll 3, the refrigerant sucked from the suction chamber 10 through the suction pipe 14 is gradually compressed in the compression chamber 9 and discharged into the sealed container 1 from the discharge port 4c.

  The lower end of the crankshaft 5 extends to an oil sump 12 at the bottom of the sealed container 1. The crankshaft 5 includes a through hole 5a, supplies the lubricating oil 13 to the bearings and the sliding surface through the through hole 5a, and reduces the leakage of refrigerant during compression by forming an oil film in the compression chamber 9. Therefore, the refrigerant discharged from the discharge port 4c into the sealed container 1 contains the mist of lubricating oil 13.

  Next, with reference to FIG. 2 to FIG. 5, the flow of the refrigerant and the lubricating oil 13 discharged into the sealed container 1 from the discharge port 4 c of the compression mechanism unit 2 is shown. In FIG. 2, a solid line arrow indicates the flow of the lubricating oil 13, and a dotted line arrow indicates the flow of the refrigerant discharged into the sealed container 1 from the discharge port 4c. FIG. 4 is a cross-sectional view of the compression mechanism 2 as viewed from below. FIG. 5 is a cross-sectional view of the electric motor unit 7 as viewed from below.

  The refrigerant including the mist-like lubricating oil 13 discharged from the discharge port 4 c into the sealed container 1 passes through the discharge gas flow path 20 provided in the outer peripheral portion of the compression mechanism unit 2 and below the compression mechanism unit 2. It is guided to the space (the upper space 22 of the electric motor unit 7). In this process, a part of the lubricating oil 13 contained in the refrigerant is separated and is transmitted to the inner surface of the sealed container 1 and stored in the oil reservoir 12 below the sealed container 1. Further, the refrigerant is guided to the lower space 23 of the electric motor unit 7 through the flow path 21 provided on the outer periphery of the electric motor unit 7. In this process, a part of the lubricating oil 13 contained in the refrigerant is further separated and is stored in the oil reservoir 12 below the sealed container 1 through the inner surface of the sealed container 1 and the like. The direction in which the refrigerant flows thereafter reverses, passes through the air gap 19 that is a gap between the rotor 15 and the stator 16 of the motor unit 7 and the flow path 24 that passes through the interior of the rotor in the axial direction. Guided to the upper space 22.

  At this time, the refrigerant contacts the lubricating oil 13 stored in the oil reservoir 12 in the space 23 below the electric motor unit 7 in addition to the oil that could not be separated, so that the crankshaft 5 and the rotor 15 are rotated. Along with this, the misted lubricating oil 13 is also included. That is, when the air is passed through the air gap 19 or the passage 24 passing through the inside of the rotor in the axial direction and led to the space 22 above the electric motor unit 7, the refrigerant contains the misting lubricant 13.

  On the upper and lower end surfaces of the rotor 15, there are installed balance weights 15 that are balanced parts for canceling out the unbalanced force caused by the eccentric rotation of the crankshaft 5 and the orbiting scroll 3 and keeping the vibration of the compressor low. The The balance weight 15 is formed so that the outer peripheral surface of the tip protrudes upward from the upper end coil 16a over the entire circumference in the space 22 above the electric motor unit 7 in order to suppress oil mist formation accompanying the rotation of the rotor 15. Is done. The balance weight 15 has a weight portion 15e that is filled with a metal about half a circumference. The portion excluding the weight portion 15e constitutes a balance weight internal space 30 that is a gap that communicates the rotor internal flow passage 24 that is a flow passage penetrating the rotor inside in the axial direction and the space 22 above the motor portion 7. To do.

  In this embodiment, as shown in FIG. 3, the upper balance weight 15a penetrates the upper balance weight 15a radially outward from the balance weight inner space 30, and the balance weight inner space 30 and the vicinity of the end coil 16a. A radial through hole 25 communicating with the space 31 is provided. With such a configuration, the rotation of the rotor 15 causes the mixture of oil and refrigerant to be discharged from the balance weight 15 through the radial through hole 25 and collide with the end coil 16a, etc. Oil and refrigerant gas can be separated without blowing refrigerant gas containing oil that has fallen through the crankshaft 5 or oil that has risen through the passage 24 in the rotor in the space near the discharge pipe 17. .

  Further, in order to form the radial through hole 25 so as to open also to the rotor upper end surface 32 (so as to open also below the upper balance weight 15a in the crankshaft direction), the diameter after forming the balance weight 15 is reduced. There is no need to drill the direction through hole 25. That is, in the production by a die casting method such as zinc die casting, the radial through hole 25 is formed at the same time as the balance weight 15 by forming the radial through hole 25 in the rotor upper end surface 32 serving as a die matching surface. Can be configured. Furthermore, since the radial through-hole 25 can be formed without adding members such as an oil separation plate, a spacer, and an oil separation block, it can be discharged from a sealed container without increasing the number of work steps and costs during assembly. It is possible to provide a hermetic electric compressor in which the oil content of the refrigerant to be reduced is reduced.

  A second embodiment of the present invention will be described. The second embodiment is different from the first embodiment in the following points, and is basically the same as the first embodiment in other points. FIG. 6 is a perspective view showing a balance weight 15a portion of the hermetic electric compressor of this embodiment.

  As shown in FIG. 6, a protrusion 40 is provided from the inner surface 15 d of the balance weight toward the crankshaft (inward in the radial direction) so as to contact the radial through hole 25. The protrusion 40 is disposed on the opposite side to the rotation direction of the rotor with respect to the radial through hole 25. FIG. 7 is an enlarged top view showing the protrusion 40. The protrusion width 40a is set to be equal to the balance weight side wall thickness 15f in order to ensure mechanical strength. Further, the opening width (depth) 40b of the protrusion is preferably long enough to collect oil droplets adhering to the inner surface 15d of the balance weight. In this embodiment, the protrusion width (depth) 40b is about three times the balance weight side wall thickness 165f. Set. From the protrusion 40, the oil that adheres to the inner side surface 15d of the balance weight and collides with the oil flowing in the circumferential direction can be easily discharged from the radial through hole 25.

  A third embodiment of the present invention will be described. The third embodiment is different from the second embodiment in the following points, and is basically the same as the second embodiment in other points. FIG. 8 is a perspective view showing a balance weight 15a portion of the hermetic electric compressor of this embodiment.

  As shown in FIG. 8, a protrusion 41 is provided from the inner surface 15 d of the balance weight toward the crankshaft (inward in the radial direction) so as to contact the radial through hole 25. The protrusion 41 is further inclined in the rotational direction of the rotor from the inner side surface 15d of the balance weight toward the inside in the radial direction. FIG. 9 is an enlarged top view showing the protrusion 41. The inclination angle 41 a of the protrusion 41 was set to 90 ° with respect to the radial through hole 25. Further, the opening width 41b between the inner surface 15d of the balance weight and the protrusion is preferably long enough to collect oil droplets attached to the inner surface 15d of the balance weight. It was set to about 3 times 15f. The protrusion 41 can guide the oil that adheres to the inner side surface 15d of the balance weight and flows in the circumferential direction to the radial through hole 25, and can prompt the oil to be discharged to the end coil 16a side.

DESCRIPTION OF SYMBOLS 1 ... Airtight container, 2 ... Compression mechanism part, 3 ... Orbiting scroll, 3a ... Spiral wrap of the orbiting scroll 3, 3b ... Orbiting scroll end plate, 4 ... Fixed scroll, 4a ... Screw wrap of fixed scroll 4; 4b ... Fixed scroll suction port; 4c ... Fixed scroll discharge port; 5 ... Crank shaft; 5a ... Crank shaft oil hole; 7 ... electric motor part, 8 ... Oldham ring, 9 ... compression chamber, 10 ... suction chamber, 11 ... lid of sealed container, 12 ... oil sump, 13 ... Lubricating oil, 14 ... suction pipe, 15 ... rotor, 15a ... upper balance weight, 15b ... lower balance weight, 15c ... outer surface of upper balance weight, 15d ... upper balance Weight inner surface, 15e ... weight part, 15 ... balance weight side wall thickness, 16 ... stator, 16a ... end coil, 17 ... discharge pipe, 18 ... oil separation plate, 19 ... air gap, 20 ... discharge Gas flow path, 21... Plural flow paths, 22... Space above the motor unit 7, 23... Space below the motor unit 7, 24. -Radial through hole, 30 ... balance weight internal space, 31 ... space near end coil 16a, 32 ... rotor upper end surface, 40 ... projection, 40a ... projection width, 40b ..Projection height, 41... Projection, 41a... Tilt angle, 41b.

Claims (4)

A sealed container;
A compression mechanism having a fixed scroll, an orbiting scroll that forms a compression chamber with the fixed scroll, and a discharge port that discharges the refrigerant compressed in the compression chamber to a discharge pressure space in the sealed container;
An electric motor unit having a rotor and a stator and driving the compression mechanism unit;
A crankshaft for transmitting the rotational force of the rotor to the orbiting scroll;
An oil reservoir for storing lubricating oil at the bottom of the sealed container;
A suction port for guiding the refrigerant into the sealed container;
A discharge port for discharging the refrigerant compressed in the compression chamber outside the sealed container;
A balance weight provided between the compression mechanism portion and the rotor and provided on the crankshaft, including a weight portion filled with metal and an internal space having a gap;
With
The compressor is characterized in that the balance weight has a through hole that penetrates the balance weight from the inner space toward the outside in the radial direction. In claim 1,
The compressor is further characterized in that the through hole penetrates downward from the internal space in the crankshaft direction. In claim 1 or 2,
The compressor according to claim 1, further comprising a protrusion directed radially inward from an inner surface of the balance weight on a side opposite to a rotation direction of the rotor of the through hole. In claim 3,
The compressor is characterized in that the protrusion is inclined from the inner surface of the balance weight toward the inner side in the radial direction toward the rotation direction of the rotor.