JP2529355B2 - Hermetic electric gas compressor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to oil separation and refueling of a hermetic electric compressor and cooling of the electric motor.

2. Description of the Related Art Lubricating oil used in rotary, screw, scroll, etc. refrigerant compressors is used not only for lubrication of sliding parts, but also for the reason that it is difficult to manufacture an appropriate compression chamber sealing member. It is also used to improve the compression efficiency by mixing the lubricating oil of (1) with the intake refrigerant gas and sealing the compression chamber gap with an oil film to prevent the compressed refrigerant gas from leaking.

In particular, scroll refrigerant compressors with excellent low vibration and low noise characteristics eliminate the adverse effects of difficulty in securing high dimensional accuracy and large variations in dimensional accuracy due to the complicated spiral shape of the components that form the compression chamber. Therefore, it is often expected that the dimensional accuracy of the spiral portion is optimized and the compressor performance is stabilized by the positive sealing effect using the oil film of the lubricating oil. For example, as disclosed in JP-A-57-8386, a method is known in which lubricating oil in an oil reservoir communicating with the discharge chamber is injected into the compression chamber.

However, this method also has a prerequisite that the lubricating oil in the discharged refrigerant gas is separated and collected in the oil reservoir.

As this method, as shown in FIG. 3, a configuration is shown in which the discharged refrigerant gas is discharged to the electric motor installation space and the lubricating oil is separated from the discharged refrigerant gas by using the inertial force of the lubricating oil in the discharged refrigerant gas. .

The figure shows a scroll compression unit 302 and an oil sump 30 in a closed container 301.
8 is placed in the lower part and electric motor 303 is placed in the upper part for storage.
Discharge port of scroll compression unit 302 and lower space of electric motor 303
316 is communicated with a discharge pipe 310 provided through the closed container 301, and an oil separator 313 is provided between the discharge pipe 312 provided on the upper end wall of the closed container 301 and the upper space 317 of the electric motor 303. This is the configuration (Japanese Utility Model Publication No. 57-69991).

However, in the configuration in which the discharge pipe 310 as shown in FIG. 3 is opened in the lower space 316 of the electric motor 303, in order to effectively separate the lubricating oil from the discharged refrigerant gas, the lower space is reduced.
316 needs to be increased. Increasing the lower space 316 causes the electric motor 303 connected to the compression unit to move away from the compression unit, and a large bending moment acts on the drive shaft connecting the compression unit and the rotor of the electric motor 303,
Gives a large bend to the drive shaft. The bending of the drive shaft gives an abnormal one-sided contact phenomenon to the bearing portion of the compression portion supporting the drive shaft, resulting in damage to the bearing portion. In addition, the bending of the drive shaft imbalances the air gap between the stator and the rotor of the electric motor 303. As a result, the electromagnetic force generated between the stator and the rotor becomes unbalanced, and a larger bending moment acts on the drive shaft, increasing the bending of the drive shaft. This bending increases during high-speed operation of the compressor, causing fatal damage to the bearing. Further, there is a problem in that the compressor causes excessive vibration and noise due to the high speed rotation of the bent drive shaft.

As measures for improving the above-mentioned problems, the configurations shown in FIGS. 4 and 5 are considered.

That is, FIG. 4 shows that the upper space 416 between the upper end wall 401a of the closed container 401 and the oil separator 413 and the discharge port are connected to the discharge pipe 41.
The structure is such that the discharge pipe 412 communicates with each other at 0 and the open end of the discharge pipe 412 is extended to the lower portion of the oil separator 413 (Japanese Patent Laid-Open No. 57-83681).

Further, FIG. 5 shows an oil separator 523 having an appropriate width and length between the discharge pipe 522 and the discharge pipe 510 connected to the upper end wall 501 of the closed container 501, and the upper coil end of the electric motor 503. Is arranged on the upper part of the (Japanese Patent Laid-Open No. 57-83681).

However, in the structure in which the opening end of the discharge pipe 412 as shown in FIG. 4 is extended to the lower end of the oil separator 413, the distance between the electric motor and the compression unit is shortened while the upper space is reduced.
By increasing the size of 416, the lubricating oil can be effectively separated from the discharged refrigerant gas, but since the drive shaft is supported only on the side of the compression part, bending of the drive shaft and damage to the bearing part and noise due to it will occur. It is not a fundamental solution to vibration generation. In addition, there is a problem that the size of the compressor becomes large because the upper space 416 needs to be large.

Further, the configuration of FIG. 5 has the same problem as in the case of FIG.

On the other hand, Japanese Patent Publication No. 41-11507 discloses a method capable of effectively separating lubricating oil from discharged refrigerant gas without increasing the size of the compressor.

That is, the compression section in which the electric motor is connected to the upper part is housed in a closed container having a high-pressure atmosphere inside, and the high-pressure discharge pipe for finally delivering the compressed refrigerant gas to the outside of the machine is provided on the side opposite to the compression section with respect to the electric motor. It is provided at the end of the hermetic container, and one end is opened close to the side or end face of the coil end on the side opposite to the compression part of the electric motor, and the other end is connected to the upper exhaust chamber of the compression part and bypasses the hermetic container. A pipe outside the sealed container is provided, and the lubricating oil is separated from the gas flow by the swirling action of the rotor's rotation, and an oil reservoir for collecting the lubricating oil is provided at the bottom of the electric motor, and the drive shaft connected to the electric motor is installed. The structure is supported only by the compression unit.

In this configuration, by blowing the discharged refrigerant gas to the coil end, the lubricating oil in the refrigerant gas can be attached and captured on the winding coil with a large surface area, and the separated lubricating oil flows down in the winding coil layer and is collected in the oil sump. Therefore, the large oil separation space as described above is not required, and the compressor can be prevented from increasing in size.

However, also in this configuration, as in the case of FIGS. 4 and 5 described above, since the drive shaft is supported only by the compression portion, the bending phenomenon of the drive shaft occurs and the bearing portion is damaged during high-speed operation of the compressor. Therefore, there was a problem of causing excessive vibration and noise.

On the other hand, Japanese Patent Laid-Open No. 126285/1987 discloses a structure for solving the damage of the bearing and the generation of excessive vibration and noise.

That is, the scroll compression part at the top in the closed container,
The electric motor is housed in the lower portion, the oil reservoir for bearing lubrication is arranged in the bottom portion, and the bearings supporting the drive shaft connected to the electric motor are arranged on both sides of the electric motor.

However, in this configuration, the space where the electric motor and the oil sump are at a low pressure equal to the suction pressure, and the high pressure space equal to the discharge pressure is located above the compression section, and is used for sealing the compression chamber gap and sliding surface lubrication. Since a wide high-pressure space for separating the generated lubricating oil from the discharged gas is required, the problem that the compressor becomes large remains, and there is a problem that the above problems cannot be solved at the same time.

Therefore, in the present invention, the drive shaft is supported on both sides of the electric motor, the discharge gas discharged from the compression section is made to collide with the winding coil end of the electric motor to separate the lubricating oil, and the bearing frame also serves as oil separation and recovery. The present invention also provides a gas compressor that is small in size, excellent in durability, and low in vibration and noise by separating and recovering lubricating oil and supplying the lubricating oil to the bearing portion.

Means for Solving the Problems In order to solve the above problems, the hermetically-sealed electric compressor of the present invention is a discharge pipe provided at the end of a hermetically sealed container and a coil end portion on the side opposite to the compression portion of an electric motor in the middle of a discharge gas passage. A bearing frame to support the anti-compression part side of the drive shaft supported on both sides of the motor, and after a part of the lubricating oil contained in the discharge gas collides with the coil end part, The bearing frame is provided with a passage that is separated from the discharged gas at the periphery and is guided to the bearing sliding portion at the center of the bearing frame.

Operation According to the present invention, the lubricating oil contained in the discharge gas discharged from the compression section is separated and collected by the coil end section of the electric motor and the bearing frame, and is supplied to the bearing section supporting the drive shaft. The drive shaft supported by the bearings on both sides of the electric motor has little bending at the center, and can smoothly slide and rotate without being supported by one-sided bearings.

Embodiment Hereinafter, a scroll refrigerant compressor according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a vertical sectional view of a scroll refrigerant compressor according to an embodiment of the present invention, and FIG. 2 is an exploded view of main parts.

In FIG. 1, 1 is an iron-made closed case (closed container)
Then, in a high pressure atmosphere where the entire interior communicates with the discharge chamber 2,
A motor (electric motor) 3 is arranged in the upper part, a compression part is arranged in the lower part, and a main body frame 5 of the compression part which supports a drive shaft 4 fixed to a rotor 3a of the motor 3 makes the inside of the sealed case 1 a motor chamber 6. It is partitioned into the discharge chamber 2. Body frame 5
Is made of an aluminum alloy with excellent heat conduction characteristics mainly for weight reduction and heat dissipation of the bearing, and an iron liner 8 with excellent weldability is shrink-fitted and fixed to the outer periphery of the liner 8.
The outer peripheral surface is inscribed in the entire circumference of the closed case 1 and is partially welded and fixed.

The outer peripheral portions of both ends of the stator 3b of the motor 3 are supported and fixed by a bearing frame 9 and a main body frame 5 which are internally fixed to the hermetically sealed case 1. The drive shaft 4 includes an upper bearing 10 provided on the bearing frame 9, a lower bearing 11 provided on an upper end portion of the main body frame 5, a main bearing 12 provided on a central portion of the main body frame 5, an upper end surface of the main body frame 5. Rotor of motor 3
It is supported by a thrust ball bearing 13 provided between the lower end surface of 3a and an eccentric bearing 14 which is eccentric from the main shaft of the drive shaft 4 at its lower end.

A fixed scroll 15 made of aluminum alloy is fixed to the lower end surface of the body frame 5. The fixed scroll 15 is composed of a spiral fixed scroll wrap 15a and an end plate 15b. A discharge port 16 that opens to the winding start portion of the fixed scroll wrap 15a is provided in the center of the end plate 15b so as to communicate with the discharge chamber 2, and a suction chamber 17 is provided on the outer peripheral portion of the fixed scroll wrap 15a. There is.

A spiral orbiting scroll wrap 18a that meshes with the fixed scroll wrap 15a to form a compression chamber, and the drive shaft 4
The orbiting scroll 18 made of an aluminum alloy, which is composed of an orbiting shaft 18b supported by an eccentric bearing 14 and a lap support disk 18c which is upright, is arranged surrounded by a fixed scroll 15, a main body frame 5 and a drive shaft 4. A sleeve 19 made of a high-strength steel material is shrink-fitted and fixed to the outer peripheral portion of the swivel shaft 18b, and the surface of the lap support disk 18a is hardened.

Split pin type parallel pin fixed to the body frame 5
Thrust bearing 20 that is constrained by and can move only in the axial direction
And the end plate 15b of the fixed scroll 15 between the spacer 2
1 is provided, and the axial dimension of the spacer 21 is set to be about 0.015 to 0.020 mm larger than the thickness of the lap supporting disk 18c in order to improve the sealing property of the sliding surface by the oil film.

The eccentric bearing space 36 between the bottom portion of the eccentric bearing 14 of the drive shaft 4 and the shaft portion of the orbiting shaft 18b of the orbiting scroll 18, and the outer peripheral space 37 of the lap supporting disk 18c are the orbiting shaft 18b and the wrap supporting circle. The plate 18c is communicated with by an oil hole A38a provided in the plate 18c.

The thrust bearing 20 is made of a sintered alloy, and as shown in FIG. 2, the center portion thereof is formed by penetrating into a shape including two parallel straight line portions and two arcuate curved line portions 23 continuous with the straight line portions.

The rotation preventing member (hereinafter referred to as Oldham ring) 24 of the orbiting scroll 18 is made of a light alloy or a reinforced fiber composite resin material suitable for sintering molding, injection molding, etc., and also has oil impregnation characteristics, as shown in FIG. A thin annular plate 24a whose both surfaces are parallel to
The outer contour of the annular plate 24a is composed of a pair of parallel key portions 24b provided on one surface of the parallel plate portion 24b.
And two arcuate curved portions 26 connected to it,
As shown in FIG. 2, the linear portion 25 is slidable by engaging the linear portion 22 of the thrust bearing 20 with a small clearance, and the side surface 24c of the parallel key portion 24b is orthogonal to the central portion of the linear portion 25. , First
The lap support disk of the orbiting scroll 18 as shown in FIGS.
Engage with a pair of key grooves 71 provided in 18c with a minute gap,
It has a slidable shape.

As shown in FIG. 1, a release gap 27 of about 0.1 mm is provided between the body frame 5 and the thrust bearing 20, and an annular groove 28 is also provided in the body frame 5 so as to face the release gap 27. Rubber seal ring 70 surrounding the annular groove 28
Is mounted between the body frame 5 and the thrust bearing 20.

The upper portion of the motor chamber 6 and the discharge chamber 2 are communicated with each other through a bypass discharge pipe 29 connected to penetrate the side wall of the sealed case 1, and the opening position of the bypass discharge pipe 29 to the motor chamber 6 is the stator. The upper opening end of the bypass discharge pipe 29 and the discharge pipe 31 connected to the upper end of the hermetic case 1 facing the side surface of the coil end 30 of 3b are the hole 32 provided in the bearing frame 9 and the hermetic case 1. Disposed between the upper surface and the bearing frame 9,
It communicates via a punching metal 33 having a large number of small holes.

A spiral oil groove 90 is provided on the surface of the upper end shaft 4b of the drive shaft 4 that engages with the upper bearing 10, and the end of the oil groove 90 opens to the end surface of the upper end shaft 4b. The drive shaft 4 is provided so as to transfer the lubricating oil toward the motor 3 when the drive shaft 4 rotates forward.

An oil hole 91 that is provided in the bearing frame 9 in a tilted manner and provided near the drain hole 32 connects the coil end 30 side and the end side of the upper shaft 4b.

The glass terminal 92 for connecting the external power source and the connector 93 for connecting to the motor side are connected at a position penetrating the punching metal 33.

The oil sump 34 provided at the bottom of the motor chamber 6 is
And a cooling passage 35 formed by cutting a part of the outer periphery of the stator 3b of the motor 3 to communicate with each other. Also, the oil sump 34
Communicates with the annular groove 28 through the oil hole B38b provided in the main body frame 5, and at the same time, the back pressure chamber 39 of the orbiting scroll 18 in which the Oldham ring 24 is arranged has a small gap in the sliding portion of the main bearing 12. Through the oil groove A4 provided in the eccentric bearing 14
It also communicates with the eccentric bearing space 36 via 0a.

Further, the oil hole B38b provided in the main body frame 5 also communicates with a spiral oil groove 41 provided on the surface of the lower shaft portion 4a corresponding to the lower bearing 11 of the drive shaft 4, and the spiral oil groove 41 The winding direction is provided so that a screw pump action utilizing the viscosity of the lubricating oil is generated when the drive shaft 4 rotates in the forward direction, and the end thereof is formed partway along the lower bearing 4a.

The fixed scroll 15 is provided with an arc-shaped suction passage 42 that communicates both ends of the suction chamber 17, and a circular suction hole 43 that is orthogonal to the circular suction passage 42 is also provided in a direction perpendicular to the side surface of the fixed scroll wrap 15a. The bottom of the hole 43 is flat and the suction passage is
It has reached the side of 42.

In addition, the suction hole 43 has a suction pipe 47 of the accumulator 46.
Is connected between the bottom surface 44 of the suction hole 43 and the suction pipe end surface 48, and is larger than the inner diameter dimension of the suction tube 47 and the suction hole depth dimension between the suction tube end surface 48 and the bottom surface 44. A check valve 50 made of a circular thin steel plate having a size larger than the opening size is arranged.

The surface of the check valve 50 has poor oil wetting characteristics and is coated with Teflon or rubber having a high elasticity.

The compression chamber 51, which does not communicate with the suction chamber 17 and the discharge chamber 2, and the outer peripheral space 37, have a small diameter injection hole 52 that is opened in the compression chamber 51 and is provided in the end plate 15b, the end plate 15b and resin heat insulation. A large-diameter portion 56 of the oil hole C38c communicates with an injection passage 55 formed of an injection groove 54 formed with the cover 53 and a stepped oil hole C38c opening in the outer peripheral space 37.
Has a check valve 58 made of thin steel plate with a cutout on a part of the outer circumference.
And a coil spring 59 are arranged.

The coil spring 59 is pressed by the heat insulating cover 53 and constantly urges the check valve 58. The opening position of the oil hole C38c to the outer peripheral space 37 is provided at a position that is intermittently opened and closed every time the lap support disk 18 of the orbiting scroll 18 orbits.

The operation of the scroll refrigerant compressor configured as described above will be described.

When the drive shaft 4 is rotationally driven by the motor (electric motor) 3, the orbiting scroll 18 orbits, and the suction refrigerant gas containing lubricating oil from the refrigeration cycle connected to the compressor is sucked into the suction pipe 47 connected to the accumulator 46. The orbiting scroll 18 flows through the suction hole 43 and the suction passage 42 in order to flow into the suction chamber 17.
And the fixed scroll 15 and the suction chamber 17
A second compression chamber that is constantly enclosed in a compression chamber through a first compression chamber (not shown) that communicates intermittently with the
51a and 51b are sequentially transferred and compressed to a third compression chamber (not shown) which is intermittently in communication with the discharge chamber 2, and the discharge port 16 at the center is provided.
And then discharged into the discharge chamber 2.

The discharge refrigerant gas containing the lubricating oil passes through the bypass discharge pipe 29 that is piped to the outside of the compressor, and again passes through the motor chamber 6 in the compressor.
After returning to, the discharge pipe 31 is discharged to the external refrigeration cycle, but when flowing into the motor chamber 6, it collides with the side surface of the coil end 30 of the motor 3 and adheres to the surface of the motor winding. As a result, a part of the lubricating oil is separated and captured by the coil end 30 as fine oil droplets. The oil droplets are discharged through the vent hole 32 provided in the bearing frame 9 together with the discharged refrigerant gas.
When passing through, by changing the flow direction, a large oil droplet grows due to the inertial force of the lubricating oil and the surface adhesion to the bearing frame 9, and the lubricating oil is effectively separated from the discharged refrigerant gas. A part of this lubricating oil is supplied to the upper bearing 10 through the oil hole 91 of the bearing frame 9 and is also collected in the dent portion in the central portion. Further, the lubricating oil in the discharged refrigerant gas is captured by the surface adhesion even when passing through the small holes of the punching metal 33, and is collected in the recessed portion at the center of the bearing frame 9. Part of this lubricating oil is supplied to the sliding surface of the upper bearing 10 by the screw pump action of the oil groove 90 and its own weight, and then flows down along with the remaining lubricating oil on the surface of the cooling passage 35 and the motor winding, The oil is collected in the oil sump 34 while cooling the motor 3.

The drive shaft 4 that receives a bending moment from the orbiting shaft 18b of the orbiting scroll 18 on which a compressive load acts and tilts in the sliding surface of the upper bearing 10 and the main bearing 12 is supported by an oil film generated on the sliding surface. It

On the other hand, the lubricating oil in the oil sump 34 is generated by the screw pump action of the spiral oil groove 41 provided on the surface of the lower shaft portion 4a of the drive shaft 4.
When the lubricating oil is supplied to the thrust ball bearing 13 and the lubricating oil passes through the minute bearing gap at the end of the lower bearing 4a, the oil film sealing action creates a discharge refrigerant gas atmosphere in the motor chamber 6 and an upstream space of the main bearing 12. Is cut off.

The lubricating oil containing the dissolved refrigerant gas in the oil sump 34 is reduced to an intermediate pressure between the discharge pressure and the suction pressure when passing through the minute gap of the main bearing 12, and flows into the back pressure chamber 39. After that, the oil groove A40a of the eccentric bearing 14, the eccentric bearing space 36, and the oil hole A38 passing through the orbiting scroll 18 flow into the outer peripheral portion space 37 while being gradually decompressed, and the oil hole C38c and the injection groove 54 which are intermittently opened. , Through the injection holes 52a, 52b into the second compression chambers 51a, 51b and lubricate the sliding surfaces in the middle of the passages.

The lubricating oil injected into the second compression chambers 51a and 51b merges with the lubricating oil that has flowed into the compression chamber together with the suction refrigerant gas from the refrigeration cycle outside the compressor, and seals the minute gap between the adjacent compression chambers with an oil film. The compressed refrigerant gas is prevented from leaking, and the sliding surface between the compression chambers is lubricated, and the compressed refrigerant gas is discharged again to the discharge chamber 2.

Further, since the oil sump 34 also communicates with the annular groove 28 and the release gap 27, the thrust bearing 20 is biased by the back pressure thereof and comes into contact with the end surface of the spacer 21. Then, the lap support disk 18c of the orbiting scroll 18 smoothly slides while maintaining a small gap between the thrust bearing 20 and the end plate 15b of the fixed scroll 15, and at the same time, the end surface of the fixed scroll wrap 15a and the lap support circle. The gaps between the plate 18c and between the end face of the orbiting scroll wrap 18a and the end plate 15b are also kept small, and the refrigerant leakage between the adjacent compression chambers is reduced.

An annular ring 82, which is an elastic body that makes an orbiting motion following the orbiting scroll 18, scrapes the lubricating oil on the sliding surface of the thrust bearing 20 in contact with the lap support disk 18c and collects it around the annular groove 81. Then, the gap between the annular groove 81 and the annular ring 82 and the gap between the annular ring 82 and the thrust bearing 20 are oil-sealed. As a result, the back pressure chamber 39 is always filled with lubricating oil, and the sliding surfaces of the main bearing 12 and the slewing bearing 14 are also filled with lubricating oil,
The inclination of the drive shaft 4 in the bearing gap is prevented, and the upper bearing 10
It assists the smooth sliding of the drive shaft 4 inside.

The openings of the injection holes 52a, 52b of the second compression chambers 51a, 51b change in pressure according to the orbiting angle of the orbiting scroll 18, and are more instantaneous than the back pressure chamber pressure that changes following the pressure in the discharge chamber 2. But the average pressure is low. Therefore, the lubricating oil from the back pressure chamber 39 is intermittently opened and closed by the sliding surface of the lap support disc 18c at the end plate opening end of the oil hole C38c, and is injected through the injection passage 55 while being refueled. It flows into the compression chambers 51a and 581b. Then, the compressed refrigerant gas in the second compression chambers 51a, 51b, which is instantaneously higher than the pressure in the back pressure chamber during normal operation, is attenuated by the injection holes 52a, 52b having a small diameter. There is no general backflow, and the pressure in the injection groove 54 does not become higher than the back pressure chamber pressure.

In addition, the oil hole from the outer peripheral space 37 per one rotation of the drive shaft 4
The flow rate of lubricating oil flowing into C38c is adjusted to be large when the rotation speed of the drive shaft 4 is slow and small when the rotation speed of the drive shaft 4 is fast, and the amount of oil injection into the second compression chambers 51a, 51b is correspondingly. Increase or decrease.

The lubricating oil injected into the second compression chambers 51a and 51b merges with the lubricating oil that has flowed into the compression chambers together with the suction refrigerant gas, and seals the gap between the adjacent compression chambers with an oil film to prevent compressed gas leakage and compression. It is discharged into the discharge chamber 2 together with the compressed gas while lubricating the sliding surface between the chambers. After that, the discharge refrigerant gas containing the lubricating oil is cut off by the main body frame 5 between the motor chamber 6 and the discharge chamber 2, and therefore passes through the bypass discharge pipe 29 and is naturally cooled while the coil end 30 of the motor chamber 6 is being cooled. Flows toward the upper side of the. The discharge refrigerant gas that has flowed into the motor chamber 6 collides with the winding of the coil end 30, and the lubricating oil in the discharge refrigerant gas is captured on the surface of the winding or between the windings, or the direction of the discharge refrigerant gas flow is Due to the inertial force of the lubricating oil when changing, it separates from the discharged refrigerant gas and grows into small oil droplets. This oil content is carried to the discharged refrigerant gas, and a part of it is separated from the discharged refrigerant gas by surface attachment to the bearing frame 9, and is supplied to the sliding surface of the upper bearing 10 through the oil hole 91. The remaining oil drops are the holes 32 in the bearing frame 9.
After passing through, a large amount of oil grows due to surface adhesion to the bearing frame 9, and is collected in the upper bearing oil sump 94 in the central portion.
The lubricating oil that has not been separated from the discharged refrigerant gas grows into small oil droplets due to the change in the flow direction caused by passing through the vent hole 32 of the bearing frame 9, and then the punching metal.
When passing through the small hole 33, it collides with surrounding components and changes the flow direction, and is separated by the surface adhesion of the lubricating oil and the inertial force of the lubricating oil, and part of it eventually becomes the oil sump 34 To be collected. The lubricating oil in the upper bearing oil sump 94 is supplied to the sliding surface of the upper bearing 10 by the screw pump action of the spiral oil groove provided in the drive shaft 4.

As a result, the drive shaft 4 supported by the oil film of the lubricating oil supplied to the upper bearing 10 and the main bearing 12 rotates smoothly without causing partial bearing contact.

A part of the lubricating oil captured by the coil end 30 passes through the surface of the multiple windings, between the windings, and the cooling passage 35, and then passes through the coil end 30.
While cooling down the motor 3 while flowing down to the bottom of the
To be collected.

The lubricating oil in the discharged refrigerant gas is almost separated in the motor chamber 6 because the flow velocity of the discharged refrigerant gas is low and the mixing amount is small during the low speed operation of the compressor, but the separation efficiency of the lubricating oil is poor during the high speed operation. Therefore, a part of the lubricating oil is discharged to the external refrigeration cycle together with the discharged refrigerant gas, and returns to the compressor via the accumulator 46 again.

Further, the lubricating oil differentially supplied to the back pressure chamber 39 causes the elastic force of the seal ring 70 and the urging force of the intermediate pressure to act on the orbiting scroll 18, so that the lap support disk 18c slides on the end plate 15b. A pressure oil film seal is provided to block the communication between the outer peripheral space 37 and the suction chamber 17, and also the gap between the sliding surfaces of the thrust bearing 20 and the lap support disk 18c is sealed.

In addition, for a while after the cold start of the compressor, the discharge chamber 2
Is lower than the pressure of the second compression chambers 51a, 51b, the refrigerant gas in the middle of compression tries to flow back from the second compression chambers 51a, 51b to the back pressure chamber 39 via the injection passage 55, but the check valve The reverse action of 58 prevents reverse flow to the outer peripheral space 37, and the lubricating oil in the oil sump 34 increases in pressure in the discharge chamber 2 and the back pressure chamber.
39, the differential pressure oil is supplied to the outer peripheral space 37.

Therefore, the back pressure biasing force to the thrust bearing 20 at the initial stage of cold start is generated by the compression chamber pressure, and the thrust bearing 20 slightly moves backward while resisting the thrust load trying to separate the orbiting scroll 18 from the fixed scroll 15. By expanding the axial gap between the orbiting scroll 18 and the fixed scroll 15 to cause a leak in the compression space and reduce the pressure in the compression chamber, the compression load at the initial stage of starting is reduced.

Then, as the pressure in the discharge chamber 2 rises, the lubricating oil in the outer peripheral space 37 is measured against the biasing force of the coil spring 59 via the injection holes 52a, 52b so as to be inversely proportional to the rotational speed of the drive shaft 4. It is controlled and injected into the second compression chambers 51a, 51b.

Further, the pressure in the compression chamber when an instantaneous liquid compression occurs due to oil injection or other causes at the initial stage of cooling start or during stable operation, the abnormal pressure rise and over-compression occur, but the discharge chamber 2 and the high pressure communicating with it. Since the space volume is large, the rise in discharge chamber pressure is extremely small.

Further, due to the liquid compression, the injection groove 54 and the like communicating with the second compression chambers 51a and 51b also have an abnormal pressure rise, but due to the throttling effect of the small-diameter oil hole C38c and the check function of the check valve 58, the outer peripheral space 37 And the injection groove 54 are blocked.
Therefore, the pressure in the back pressure chamber 39 does not change, and the thrust bearing 20
There is no fluctuation in the back pressure urging force that acts on the back surface of the thrust bearing 20, and as a result, the excessive thrust force that acts on the orbiting scroll 18 during liquid compression causes the thrust bearing 20 to retract and the compression chamber pressure to drop as described above. , And then continue normal operation.

Incidentally, the thrust bearing 20 retracts during liquid compression, so that the pressure in the compression chamber is reduced during compression.

After the compressor is stopped, the orbiting scroll is performed by the pressure in the compression chamber.
Reverse orbiting torque is generated in 18, and the orbiting scroll 18 is orbited in the reverse direction, and the discharged refrigerant gas flows back to the suction side. Following the reverse flow of the discharge refrigerant gas, the check valve 50 moves, and the Teflon coating provided on the surface of the check valve 50 seals the suction pipe end surface 48 to prevent the reverse flow of the discharge refrigerant gas. The reverse orbit of the orbiting scroll 18 is stopped, and the space between the suction passage 42 and the discharge port 16 holds the discharge pressure.

In addition, the check valve 58 of the injection passage 55 is used as a boundary, and a passage communicating with the compression chamber is at a discharge pressure, but the space between the outer peripheral portion space 37 and the back pressure chamber 39 is at an intermediate position for a while. The pressure is maintained and gradually approaches the discharge pressure due to a slight inflow of lubricating oil from the oil sump 34. When the compressor is stopped, the orbiting scroll 18 rotates in the reverse direction and the third compression chamber (not shown) expands and stops at a position where reverse orbiting torque is not generated, and the opening of the oil hole C38c to the outer peripheral space 37 is lap supported. It is blocked by the disc 18c.

After the compressor is stopped, the check valve 58 shuts off the injection passage 55 by the urging force of the coil spring 59, so that no lubricating oil flows from the outer peripheral space 37 into the compression chamber.

As described above, according to the above embodiment, the motor (electric motor)
Body frame 5 and bearing frame 9 arranged on both sides of 3
The main body frame 5 connected to the motor 3 via the drive shaft 4 supported by the fixed scroll 15, the fixed scroll 15 fixed to the main body frame 5, the fixed scroll 15 to form a compression chamber, and the slide shaft is slidably engaged with the drive shaft 4. The scroll compression mechanism composed of the orbiting scroll 18 driven by the rotary orbiting scroll 18 and the Oldham ring 24 that prevents rotation of the orbiting scroll 18 is housed in the closed case 1 having a high pressure atmosphere inside, and the compressed refrigerant gas is finally compressed. The discharge pipe 31 which is sent to the outside is connected to the upper end wall of the hermetically sealed case 1 on the side opposite to the above-mentioned compression section with respect to the motor 3, and the compressed refrigerant gas discharged from the above-mentioned scroll compression mechanism section is outside the hermetically sealed case 1. Bypass discharge pipe routed around
A discharge refrigerant gas passage that flows into the sealed case 1 again via 29, collides with the coil end 30 on the side of the anti-scroll compression mechanism of the motor 3 to cool the motor 3, and then discharges it from the discharge pipe 31 to the outside of the sealed case 1. In the configuration provided with, a part of the lubricating oil contained in the discharge refrigerant gas is disposed between the coil end 30 and the discharge pipe 31 in the discharge refrigerant gas passage to prevent the drive shaft 4 from moving on the side opposite to the scroll compression mechanism portion. After colliding with the coil end 30 around the bearing frame 9 to be supported, it is separated from the discharged refrigerant gas, and the upper bearing 10 at the center of the bearing frame 9 is separated.
By providing the bearing frame 9 with a passage (upper bearing oil sump 94 and oil hole 91) that is guided to the sliding portion of, the lubrication in the discharge refrigerant gas is not required without a special oil separation space and oil supply pump device. Coil end 30 of motor 3 and bearing frame 9
In addition, the lubricant can be efficiently attached and collected, and the lubricating oil can be supplied to the bearing portion on the side opposite to the compression portion that supports the drive shaft 4, so that the compressor can be downsized. Further, the drive shaft 4 supported by the bearing portions (main bearing 12 and upper bearing 10) on both sides of the motor 3 has little bending in the central portion, and receives a bending moment from the orbiting scroll to receive the upper bearing 10 and the main body frame 5. Although it tries to incline within the sliding surface of the main bearing 12, it smoothly rotates without being hit by the bearing film supported by the oil film generated on the sliding surface, and the original scroll compressor has low vibration and low noise. The characteristics can be exhibited. Further, it is possible to reduce the input of the bearing sliding portion and improve the durability.

Furthermore, since the air gap between the rotor 3a and the stator 3b of the motor 3 can be kept uniform, the electromagnetic attraction force generated between the rotor 3a and the stator 3b is also balanced, and the compressor operates at high speed. It is possible to exhibit low vibration and low noise characteristics even at times.

Further, according to the above-described embodiment, since the vent hole 32 provided in the bearing frame 9 is arranged closer to the shaft center side than the coil end 30, the coil is provided for cooling the motor 3 and capturing the lubricating oil from the discharged refrigerant gas. The flow direction of the discharged refrigerant gas that collides with the end 30 can be changed. Thereby, the oil can be separated by utilizing the inertial force of the lubricating oil in the discharged refrigerant gas,
The reliability of the bearing can be improved by increasing the amount of oil supplied to the bearing.

As described above, according to the present invention, the compression section in which the electric motors are connected to each other via the drive shafts supported on both sides of the electric motor is housed in a hermetically sealed container having a high-pressure atmosphere, and the discharged gas is finally discharged. A discharge pipe to be sent to the outside of the machine is provided at the end of the airtight container on the side opposite to the compression unit with respect to the electric motor, and the discharge gas discharged from the compression unit again passes through the bypass discharge pipe that bypasses the outside of the airtight container. A coil in the middle of the discharge gas passage in a structure in which a discharge gas passage that flows into the closed container, collides with the coil end portion on the anti-compression part side of the electric motor, cools the electric motor, and then discharges from the discharge pipe to the outside of the closed container A bearing frame that supports the anti-compression part side of the drive shaft is provided between the end part and the discharge pipe, and after a part of the lubricating oil contained in the discharge gas collides with the coil end part, the discharge gas around the bearing frame Separated from the axis By providing the bearing frame with a passage that is guided to the bearing sliding portion at the center of the receiving frame, the lubricating oil in the discharge gas can be used as the coil end of the electric motor without requiring a special oil separation space and oil supply pump device. It can be efficiently attached to and collected on the bearing frame, and its lubricating oil can be supplied to the bearing portion on the side opposite to the compression portion that supports the drive shaft, and the compressor can be downsized. In addition, the drive shaft supported by the bearings on both sides of the motor has less bending at the center and receives a bending moment from the compression part to incline within the bearing sliding surface, but this occurs on the sliding surface. It is possible to realize a compressor that is supported by an oil film, smoothly rotates without causing bearing piece contact, and has low vibration and low noise. Further, it is possible to reduce the input of the bearing sliding portion and improve the durability.

Furthermore, since the air gap between the rotor and the stator of the electric motor can be maintained evenly, the balance of the electromagnetic attraction force generated between the rotor and the stator can also be maintained, resulting in low vibration even during high-speed operation of the compressor.・ Low noise characteristics can be exhibited.

Further, in the present invention, in order that a part of the bearing frame also serves as an oil separation function, a vent hole is provided in the bearing frame closer to the shaft center than the coil end portion, and the discharged gas is allowed to pass through the vent hole. It is possible to change the flow direction of the discharge gas that has collided with the coil end portion in order to capture the lubricating oil from the cooling and discharge gas. Thereby, oil can be separated by utilizing the inertial force of the lubricating oil in the discharged gas, and the reliability of the bearing portion can be improved by increasing the amount of oil supplied to the upper bearing portion.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a scroll refrigerant compressor according to an embodiment of the present invention, FIG. 2 is an exploded view of main parts of the compressor, and FIGS. 3, 4, and 5 are different from conventional ones. It is a longitudinal section of a scroll compressor. 1 ... Closed case (closed container), 2 ... Discharge chamber, 3 ...
Motor (electric motor), 4 ... Drive shaft, 5 ... Body frame, 9 ... Bearing frame, 15 ... Fixed scroll, 16 ...
… Discharge port, 18 …… Swirl scroll, 29 …… Bypass discharge pipe, 30 …… Coil end, 31 …… Discharge pipe, 34 …… Oil sump, 90 …… Oil groove, 91 …… Oil hole.

Claims (2)

(57) [Claims] 1. A compressor which connects the electric motor 3 via drive shafts 4 supported on both sides of the electric motor 3 is housed in a closed container 1 having a high-pressure atmosphere inside, and the discharged gas is finally discharged outside the machine. A discharge pipe 31 for delivering to the air is provided at the end of the closed container 1 on the side opposite to the compression unit with respect to the electric motor 3, and the discharge gas discharged from the compression unit bypasses the outside of the closed container 1 and is bypassed. It flows into the closed container 1 again through the discharge pipe 29, and the coil end portion 30 of the electric motor 3 on the side opposite to the compression portion 30.
In a configuration in which the electric motor 3 is cooled by collision with the discharge pipe 31 and then discharged from the discharge pipe 31 to the outside of the closed container 1, the anti-compression of the drive shaft 4 is provided between the coil end portion 30 and the discharge pipe 31. A bearing frame 9 that supports the side of the coil end is provided so that a part of the lubricating oil contained in the discharge gas is the coil end part.
After colliding with the bearing frame 30, the bearing frame 9 is separated from the discharged gas, and an oil hole 91 is provided in the bearing frame 9 to be guided to the bearing sliding portion 10 at the center of the bearing frame 9. Gas compressor. 2. A vent hole 32 is provided in the bearing frame 9 closer to the shaft center than the coil end portion 30 so that a part of the bearing frame 9 also has an oil separating function, and the discharged gas passes through the vent hole 32. The sealed electric gas compressor according to claim 1, which is intended.