JPH05133356A - Closed type scroll compressor and oil supply device thereof - Google Patents

Abstract

PURPOSE:To improve cooling of an electric motor so as to prevent a stator from its burning by connecting one end of a turning scroll and a frame bearing to an intermediate pressure chamber and the other end to a suction pressure part, and supplying oil to a bearing with a differential pressure between intermediate and suction pressures. CONSTITUTION:Delivery gas from a delivery port 5d of a fixed scroll 5 is accumulated in an oil reservoir 10 to separate oil from the delivery gas. The oil reservoir 10 is connected to an intermediate pressure chamber 8a of a scroll compressor through a throttle mechanism 12 to temporarily accumulate oil in the intermediate pressure chamber 8a. Gas of foaming for reducing a pressure from a delivery pressure to an intermediate pressure is discharged in a lap 4b through a conduction hole 4d. Oil is supplied to bearings 4c, 8b, provided in a turning scroll 4 and a frame 8, by a differential pressure between intermediate and suction pressures. In this way, an electric motor 3 is efficiently cooled by suction gas. Oil of high viscosity with small amount of refrigerant gas is supplied to bearings 4c, 8b, provided in the turning scroll 4 and the frame 8, to ensure an oil film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic scroll compressor and an oil supply device for the hermetic scroll compressor, and more particularly to a bearing portion of a hermetic scroll compressor in which an electric motor is used as a suction pressure and an intermediate pressure is applied to the rear surface of an orbiting scroll. The present invention relates to a hermetic type scroll compressor suitable for refueling and a fueling device for the same.

[0002]

2. Description of the Related Art An example of a conventional oil supply device for a bearing of a hermetic scroll compressor is disclosed in Japanese Unexamined Patent Publication No. 59-32692.
It is described in JP-A-3-64688. In the former hermetic scroll compressor having the conventional structure, oil is separated from the discharge gas in the discharge chamber surrounding the refrigerant discharge port of the fixed scroll, and the discharge chamber and the bearing are provided with an oil passage that penetrates the fixed scroll to discharge the discharge. Oil under pressure was directly supplied to the bearing by the pressure difference between the discharge pressure and the suction pressure. In addition, a thrust bearing was provided on the back of the orbiting scroll to ensure close contact between the fixed scroll and the orbiting scroll.

In the latter hermetic scroll compressor, the suction is carried out directly from the suction port of the fixed scroll, and the electric motor is cooled by the discharge gas. In addition, an intermediate pressure chamber is provided on the back of the orbiting scroll, and the orbiting scroll is brought into close contact with the fixed scroll to guide the oil separated in the oil sump container to the end face of the drive shaft, and the bearing is produced by the pressure difference between the discharge pressure and the intermediate pressure chamber. I was refueling each part.

[0004]

Of the above-mentioned conventional techniques,
The former requires a thrust bearing on the back surface of the orbiting scroll in order to prevent the orbiting scroll from separating from the fixed scroll, and the orbiting scroll comes into close contact with the thrust bearing via an oil film during compression operation. For this reason, there is a gap between the tooth tips of both the wraps of the orbiting and fixed scrolls and the tooth pressure for each, and the gas during the compression leaks. For this reason, in the scroll compressor of this structure, it is common to provide a sealant at the tooth tip. As described above, as the number of parts increases, sliding loss of the thrust bearing occurs,
The efficiency of the compressor was reduced. In addition, since the oil in the discharge pressure state is directly supplied to the bearing section by the pressure difference between the discharge pressure and the suction pressure, the oil pressure drop in the bearing sliding section is large,
A large amount of the refrigerant gas separated from the oil in the sliding surface was generated, and the bearing was sometimes seized.

Further, in the latter, since the oil in the discharge pressure state is directly supplied to the bearing portion by the pressure difference between the discharge pressure and the intermediate pressure, the pressure drop in the bearing sliding portion is smaller than that in the former, but the discharge pressure state is reduced. Refrigerant gas was generated from the oil, and the formation of an oil film was hindered. Further, in order to balance the force in the axial direction of the drive shaft, it is necessary to make the pressure on both end faces in the axial direction of the drive shaft equal, and in this structure, the force in the axial direction is not balanced unless the electric motor portion is in the discharge pressure state. For this reason, the electric motor is in the discharge pressure state and it is necessary to cool the electric motor with the discharge gas, and the winding temperature of the motor is higher than the discharge gas temperature. It was necessary to lower the liquid refrigerant on the suction side.
In this way, control was required to keep the winding temperature of the electric motor below a certain value. Further, when the suction pressure is applied to the electric motor in this structure, it is necessary to balance the axial force of the drive shaft as described above, and it is also necessary to set the end face of the drive shaft on the orbiting scroll side to the suction pressure. In conventional scroll compressors having an intermediate pressure chamber, oil was supplied at a pressure difference between the discharge pressure and the intermediate pressure, and the electric motor section was set at the discharge pressure.

The object of the present invention is to solve the above-mentioned problems, and to improve the cooling of the electric motor to prevent the burnout of the stator and to simplify the control mechanism for keeping the winding temperature of the stator below a certain value. At the same time, the refrigerant gas is foamed from the oil before the oil is supplied to the bearing to increase the viscosity of the oil, and then the oil is supplied to the bearing to form the oil film of the bearing sliding portion. Also, in order to bring the orbiting scroll into close contact with the fixed scroll, a pressure between the suction pressure and the discharge pressure is secured on the back surface of the orbiting scroll to reduce the leakage caused by the gap between the lap tooth tip and the tooth pressure, and to prevent thrust bearings, etc. It is to provide an inexpensive and highly reliable product without providing parts.

Further, even when a plurality of compressors are used, it is necessary to reliably supply high-viscosity oil to the bearing sliding portion.

[0008]

In order to achieve the above object, the present invention provides a compression mechanism section comprising a drive shaft for orbiting a orbiting scroll with respect to a fixed scroll, a frame for supporting the drive shaft, and the like. In a hermetic scroll compressor provided with an electric motor part for driving a hermetically sealed container, and an intermediate pressure chamber having an intermediate pressure between suction pressure and discharge pressure on the back surface of the orbiting scroll, the discharge port of the fixed scroll and An oil reservoir is provided in communication, and the oil reservoir is communicated with the intermediate pressure chamber via a throttle mechanism to guide oil to the intermediate pressure chamber, and the electric motor unit is brought into a suction pressure state, and is provided on the orbiting scroll and the frame. One end of the slide bearing communicates with the intermediate pressure chamber, and the other end communicates with the suction pressure portion, and has an oil supply means for supplying oil in the intermediate pressure chamber to the slide bearing at a pressure difference between the intermediate pressure and the suction pressure. And it is characterized in Rukoto.

Further, a fixed scroll and an orbiting scroll, each of which is composed of a base plate and a spiral wrap integral with the base plate, and the two wraps are meshed with each other, and the orbiting scroll revolves with respect to the fixed scroll. A rotation preventing member, a drive shaft for orbiting the orbiting scroll with respect to the fixed scroll, a compression mechanism portion including a frame or the like supporting the drive shaft, and an electric motor portion for driving these members in a closed container. In preparation for this, the base plate of the orbiting scroll is slidably held between the base plate of the fixed scroll and the frame, and an intermediate pressure having an intermediate pressure between suction pressure and discharge pressure is provided on the back surface of the orbiting scroll. In an oil supply device for a hermetic scroll compressor having a chamber, an oil reservoir communicating with the discharge port of the fixed scroll is provided, and the oil reservoir and the The inter-pressure chamber communicates with the intermediate pressure chamber via the throttle mechanism to bring the oil into the suction pressure state, and one end of the sliding bearing provided on the orbiting scroll and the frame communicates with the intermediate pressure chamber. The other end communicates with the suction pressure portion and supplies the oil in the intermediate pressure chamber to the slide bearing at a pressure difference between the intermediate pressure and the suction pressure.

Further, in the oil supply device, the intermediate pressure chamber provided in the base plate of the orbiting scroll and the compression chamber formed by both the wraps of the orbiting and fixed scrolls communicate with each other through a through hole. The gas separated from the oil in the intermediate pressure chamber can be guided to the compression chamber, and the degassed oil can be guided to the slide bearing.

Further, the amount of oil flowing into the intermediate pressure chamber from the oil sump is adjusted by a throttle mechanism, and the amount of oil flowing out of the intermediate pressure chamber to the suction pressure portion is provided on the orbiting scroll and the frame. The pressure in the intermediate pressure chamber can be adjusted to a predetermined intermediate pressure by adjusting the resistance of the bearing portion.

Further, the oil sump is separated from the hermetically-sealed container for accommodating the compression mechanism section and the electric motor, and the hermetically-sealed container is a single or plural units, and the oil sump and the intermediate pressure in each hermetically-sealed container. It is possible to communicate with the chamber by piping through the throttling mechanism.

That is, the structure of the present invention has a fixed scroll and an orbiting scroll each of which is composed of a base plate and a spiral wrap integral with the base plate, and both wraps are engaged with each other, and a fixed scroll without rotating the orbiting scroll. A rotation preventing mechanism and a drive shaft for orbiting with respect to each other, a frame supporting the drive shaft, and an electric motor for driving are provided in a closed container, and a base plate of the orbiting scroll and a fixed scroll are provided on the back surface of the orbiting scroll. It has an intermediate pressure chamber composed of a base plate, a frame, etc., communicates the discharge port of the fixed scroll with the oil sump to bring the oil sump into the discharge pressure state, and sucks suction gas into the space of the electric motor section to cool the electric motor. The oil sump and the intermediate pressure chamber communicate with each other through a throttle mechanism to guide the oil in the oil sump to the intermediate pressure chamber and reduce the discharge pressure to the intermediate pressure. At the time of depressurization, the refrigerant gas foamed from the oil is sucked into the compression chamber formed by both wraps through the through hole provided in the base plate of the orbiting scroll. The suction pressure is applied to the surfaces of the drive shaft where the through holes are provided. One end of the slide bearing for supporting the drive shaft provided on the orbiting scroll and the frame is opened to the intermediate pressure chamber, and the other end is opened to the suction pressure portion. An oil supply groove is provided on the inner surface of the bearing or on the sliding surface of the drive shaft.The oil in the intermediate pressure chamber flows to the suction pressure section through the oil supply groove and the bearing gap, and the bearing section is supplied with the oil. It
By changing the resistance of the throttle mechanism and the resistance of the bearing sliding part, the amount of oil flowing from the oil sump to the intermediate pressure chamber and the amount of oil flowing out of the intermediate pressure chamber to the suction pressure part are determined. It is the pressure of the pressure chamber. Also, the oil sump is separated from the hermetic container that houses the compression mechanism and the electric motor, and the oil sump and the intermediate pressure chamber of each compressor are connected to each other so that oil is once stored in the intermediate pressure chamber of each compressor. After draining, the oil is supplied to the bearing.

[0014]

According to the above construction, the suction gas is introduced from the suction connection portion provided in the closed container into the closed container to cool the electric motor, and then is sucked through the suction port of the compression mechanism part and discharged through the discharge port of the fixed scroll. To be done. The discharge port communicates with the oil sump, and the oil contained in the discharge gas is separated in the oil sump. The oil in the oil sump is introduced into the intermediate pressure chamber via the throttle mechanism. The oil introduced into the intermediate pressure chamber changes from the discharge pressure to the intermediate pressure and is depressurized, so that the refrigerant gas in the oil foams. The foamed gas is discharged through a through hole provided in the base plate of the orbiting scroll to the compression formed by the wrap of the fixed scroll. The drive shaft is provided with a hole communicating in the axial direction, and the suction pressure is applied to both ends. One end of the sliding bearing provided on the orbiting scroll and the frame is open to the intermediate pressure chamber, and the other end is at suction pressure. Therefore, the pressure on both end surfaces of the slide shaft becomes an intermediate pressure and a suction pressure, and the pressure difference causes the oil in the intermediate pressure chamber to flow to the suction pressure portion to supply the bearing. The oil discharged to the suction pressure section mixes with the suction gas and is sucked through the suction port of the compression mechanism section. The amount of oil entering the intermediate pressure chamber from the oil sump is adjusted by the throttle mechanism and enters the intermediate pressure chamber from the oil sump which is the discharge pressure. Also, by providing an oil groove on the inner surface of the slide bearing and an oil groove on the surface of the drive shaft that slides with the slide bearing, the amount of oil discharged from the intermediate pressure chamber to the suction pressure section side is adjusted, The pressure is adjusted so that the orbiting scroll can come into close contact with the fixed scroll.

When one compressor or a plurality of compressors are connected to a separate oil sump for simultaneous operation and stop, the bearings and the like of the compressor are supplied with oil by the above-described operation. However, when operating multiple compressors individually, in order to reduce the starting load of the stopped compressor, a check valve is installed in the middle of the discharge part of the compressor and the oil sump piping to connect to the stopped compressor. Prevent the discharge gas from flowing backward. Also, if the compressor that is stopped is filled with oil from the oil sump, the spiral scroll and fixed scroll will be filled with oil and will not start due to liquid compression, so connect the oil sump and the compressor. A solenoid valve is installed in the middle of the supply pipe so that no oil is supplied to the compressor that is not in operation.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional view showing the overall structure of a vertical hermetic scroll compressor according to an embodiment of the present invention. Although this figure shows a vertical type, it can be easily applied to a horizontal type and will be described as a vertical type. In FIG. 1, a scroll compression mechanism 2 and an electric motor 3 for driving the scroll compression mechanism 2 are housed in a closed container 1.

The scroll compression mechanism 2 comprises an orbiting scroll 4, a fixed scroll 5, a drive shaft 7 forming a crankshaft driven by the electric motor 3, a frame 8 and a rotation preventing mechanism 9.

The orbiting scroll 4 has a spiral wrap 4b on a base plate 4a. Further, a bearing 4c into which the crank pin 7a of the drive shaft 7 is inserted is provided on the back surface of the base plate 4a, and the base plate 4a is provided with a conduction hole 4d for communicating the lap 4b space during compression and the intermediate pressure chamber 8a. It is provided.

Fixed scroll 5 fixed to frame 8
Similarly, the base plate 5a has a spiral wrap 5b. A suction hole 5c is provided on the outer peripheral portion of the wrap, and a discharge hole 5d is provided on the central portion of the wrap.

A bearing 8b for supporting the drive shaft 7, a pedestal 8c for holding the orbiting scroll 4 between the fixed scroll 5 and the frame 8 fixed to the container 1, and an appropriate pressing force for the orbiting scroll 4 are provided. An intermediate pressure chamber 8a is provided.

The orbiting scroll 4 and the fixed scroll 5 are combined with each other with the wraps 4b and 5b facing inward, and the orbiting scroll 4 is held by the fixed scroll 4 and the pedestal 8c of the frame 8. A rotation prevention mechanism 9 for preventing rotation of the orbiting scroll is installed between the rear surface of the orbiting scroll and the frame. The drive shaft 7 has a crank pin 7a whose one end is supported by the bearing 4c. A pressure equalizing hole 7b is provided in the drive shaft 7 on the center of rotation of the shaft.

The discharge hole 5d of the fixed scroll 5 is an oil sump 1
0 and discharge pipe 11 communicate with each other, and oil sump 1
The lower part of 0 and the intermediate pressure chamber 8a communicate with each other through the throttle mechanism 12, and the discharge pipe 13 is provided on the upper part. In addition, a suction pipe 15 is provided in the space 14 including the electric motor 3 of the closed container 1.
Is provided.

Next, the operation of the scroll compressor will be described. When the drive shaft 7 is rotated by the electric motor 3, the orbiting scroll 4 makes an orbiting motion without rotating due to the rotational motion of the crank pin 7a and the action of the rotation preventing mechanism 9. As a result, the space formed by the orbiting scroll 4 and the wraps 4b and 5b of the fixed scroll 5 and the base plates 4a and 5a is reduced in volume while moving to the center, and the gas sucked through the suction hole 5c is compressed and discharged. Discharge from the hole 5d. The discharged gas is guided to the oil sump 10 by the discharge pipe 11, separates oil from the gas, and is then discharged from the discharge pipe 13. On the other hand, the suction gas flows from the suction pipe 15 to the suction motor 3
After being cooled, it is sucked from the suction hole 5c of the fixed scroll 5 through the passage 1a formed between the frame 8 and the closed container 1. When the scroll performs a compression action, a force that separates the orbiting scroll 4 and the fixed scroll 5 is generated.

On the other hand, the oil in the lower portion of the oil sump 10 is drawn by the throttle mechanism 1.
The pressure difference between the discharge pressure and the intermediate pressure is introduced to the intermediate pressure chamber 8a via 2 and is reduced to the intermediate pressure. Therefore, the intermediate pressure chamber 8
Gas foams from oil in a. This foamed gas is passed through the through hole 4d provided in the base plate 4a of the orbiting scroll 4 to the wrap 4b of the orbiting scroll 4 and the fixed scroll 5,
5b and the base plates 4a, 5a are guided to a chamber having a pressure lower than that of the intermediate pressure chamber 8a during the compression and discharged from the intermediate pressure chamber 8a. One end of the bearing 4c provided in the orbiting scroll 4 opens to the intermediate pressure chamber 8a, and the other end communicates with the end surface of the drive shaft 7 and a space formed by the orbiting scroll 4, and the space is sucked by a pressure equalizing hole 7b. Has become. The bearing 4c
An oil groove 7c is provided on the surface of the crank pin 7a which slides against. The oil groove 7c may be provided on the inner surface of the bearing 4c or both. In this way, the bearing 4c provided on the orbiting scroll 4 is supplied with the oil in the intermediate pressure chamber 8a by the differential pressure between the intermediate pressure and the suction pressure, and after the oil is supplied, it is discharged to the lower part of the electric motor 3 through the pressure equalizing hole 7b. It

Similarly, the bearing 8b provided on the frame 8 has one end communicating with the intermediate pressure chamber 8a and the other end having suction pressure, and the oil in the intermediate pressure chamber 8a is supplied by the pressure difference. The oil after refueling is discharged into the space including the electric motor 3 and mixed with the suction gas, and as described above, the suction hole 5 of the fixed scroll 5 is used.
Inhaled from c.

Although the case where the oil sump 10 is integrated with a single compressor has been described above, FIG. 2 shows an embodiment in which the oil sump container 10 is provided separately. Oil sump container 1
0 and the compressor are connected by the discharge pipe 11 and the oil supply pipe 16, and each function is the same as the function described in FIG.

FIG. 3 shows an oil supply system diagram of an embodiment in which a plurality of compressors are connected to separate oil reservoirs 10 and each compressor is operated and stopped. The compressor 1 and the oil sump container 10 are connected to each discharge pipe 11 via a check valve 17, and the discharge gas does not flow backward from the compressor in operation to the compressor in stop. ing. A compressor and an oil sump container are connected to the oil supply pipe 16 via an electromagnetic valve 18, and oil is supplied to the intermediate pressure chamber of the compressor in operation,
Each solenoid valve is open or closed so that oil is not supplied to the stopped compressor.

In the above embodiment, the so-called vertical scroll compressor in which the scroll compression mechanism and the drive shaft for driving the scroll compression mechanism are arranged vertically has been described, but the so-called horizontal scroll compression in which the drive shaft is horizontally arranged in the closed container. The present invention can be easily applied to a machine.

[0030]

As described above, according to the present invention, the electric motor is efficiently operated by the intake gas. In addition, the pressure in the intermediate pressure chamber can be set to a predetermined pressure by the expansion device provided in the oil supply pipe and the oil groove in the bearing, and the orbiting scroll can be brought into close contact with the fixed scroll without the need for parts such as thrust bearings. You can drive as you please.

Further, the refrigerant gas in the oil is foamed in the intermediate pressure chamber, and this refrigerant gas can be eliminated, and the oil of high viscosity can be supplied to the bearing, so that the bearing is made highly reliable without seizing. It has become possible.

When a plurality of compressors are used, it is possible to reliably supply oil to the sliding parts of the operating compressors, even if the compressors have different capacities or operating speeds. It will be possible.

[Brief description of drawings]

FIG. 1 is a sectional view showing the overall structure of a vertical hermetic scroll compressor according to an embodiment of the present invention.

FIG. 2 is a structural diagram of another embodiment showing the oil supply system of the present invention.

FIG. 3 is a structural diagram of still another embodiment showing the oil supply system of the present invention.

[Selection of sign]

 1 Airtight container 1a Passage 2 Scroll compression mechanism 3 Electric motor 4 Orbiting scroll 4a Base plate 4b Wrap 4c Bearing 4d Conducting hole 5 Fixed scroll 5a Base plate 5b Wrap 5c Suction hole 5d Discharge hole 7 Drive shaft 7a Crank pin 7b Uniform pressure hole 8a 8a Intermediate pressure chamber 8b Bearing 8c Pedestal 9 Rotation prevention mechanism 10 Oil sump 11 Discharge piping 12 Throttling mechanism 13 Discharge piping 14 Space 15 Suction piping 16 Oil supply piping 17 Check valve 18 Solenoid valve

Front page continuation (72) Inventor Mutsunori Matsunaga 390 Muramatsu, Shimizu City, Shizuoka Prefecture Hitachi Ltd. Shimizu Plant

Claims (5)

[Claims] 1. A hermetically sealed container is provided with a compression mechanism portion, which comprises a drive shaft for orbitally driving an orbiting scroll with respect to a fixed scroll and a frame for supporting the drive shaft, and an electric motor portion for driving the compression mechanism portion. In a hermetic scroll compressor having an intermediate pressure chamber having an intermediate pressure between suction pressure and discharge pressure on the back surface of the scroll, an oil reservoir communicating with the discharge port of the fixed scroll is provided,
The oil reservoir and the intermediate pressure chamber are communicated with each other through a throttle mechanism to guide the oil to the intermediate pressure chamber, the electric motor portion is brought into a suction pressure state, and one end of a slide bearing provided on the orbiting scroll and the frame is A hermetically sealed type characterized by having an oil supply means communicating with the intermediate pressure chamber and having the other end communicating with the suction pressure portion to supply oil in the intermediate pressure chamber to the slide bearing at a pressure difference between the intermediate pressure and the suction pressure. Scroll compressor. 2. A fixed scroll and an orbiting scroll, each of which is composed of a base plate and a spiral wrap integral with the base plate, and the two wraps are engaged with each other, and the orbiting scroll orbits without rotating with respect to the fixed scroll. A rotation preventing member, a drive shaft for orbiting the orbiting scroll with respect to the fixed scroll, a compression mechanism portion including a frame or the like supporting the drive shaft, and an electric motor portion for driving these members in a closed container. In preparation for this, the base plate of the orbiting scroll is slidably held between the base plate of the fixed scroll and the frame, and an intermediate pressure having an intermediate pressure between suction pressure and discharge pressure is provided on the back surface of the orbiting scroll. In an oil supply device for a hermetic scroll compressor provided with a chamber, an oil reservoir communicating with the discharge port of the fixed scroll is provided,
The oil reservoir and the intermediate pressure chamber are communicated with each other through a throttle mechanism to guide the oil to the intermediate pressure chamber, the electric motor portion is brought into a suction pressure state, and one end of a slide bearing provided on the orbiting scroll and the frame is A hermetic scroll compressor characterized in that it communicates with an intermediate pressure chamber and the other end communicates with a suction pressure portion to supply oil in the intermediate pressure chamber to the slide bearing at a pressure difference between the intermediate pressure and the suction pressure. Refueling device. 3. The oil in the intermediate pressure chamber is provided through a conduction hole that connects the intermediate pressure chamber provided on the base plate of the orbiting scroll and the compression chamber formed by both the wraps of the orbiting and fixed scrolls. 2. The oil supply device for a hermetic scroll compressor according to claim 1, wherein the separated gas is guided to the compression chamber, and the degassed oil is guided to the slide bearing. 4. A slip provided on the orbiting scroll, the frame and the like for adjusting the amount of oil flowing from the oil sump into the intermediate pressure chamber by a throttle mechanism, and adjusting the amount of oil flowing out of the intermediate pressure chamber to the suction pressure portion. The oil supply device for a hermetic scroll compressor according to claim 1, wherein the pressure in the intermediate pressure chamber is adjusted to a predetermined intermediate pressure by adjusting the resistance of the bearing portion. 5. The oil sump is separate from the hermetically-sealed container that houses the compression mechanism section and the electric motor, and the hermetically-sealed container is a single or a plurality of units. 2. The oil supply device for a hermetic scroll compressor according to claim 1, wherein the chamber is communicated with a pipe through a throttle mechanism.