JPH05133355A - Oil supply device for closed type scroll compressor - Google Patents

Abstract

PURPOSE:To efficiently cool an electric motor by suction gas by placing an electric motor part in a condition of suction pressure, and supplying oil to a compression mechanism part with a differential pressure from an oil reservoir vessel connected to a delivery hole of a fixed scroll. CONSTITUTION:A base plate 4a of a turning scroll 4 is interposed in a slidable manner between a base plate 5a of a fixed scroll 5 and a frame 7, in a closed vessel 1. Further, an intermediate pressure chamber of intermediate pressure between suction and delivery pressures is provided in a back surface of the turning scroll 4. An electric motor part 3 is placed in a condition of suction pressure to provide an oil reservoir vessel 10 of separate unit connected to a delivery hole 5d of the fixed scroll 5. An oil path 12 for supplying oil to a compressing mechanism part 2 with a differential pressure from the oil reservoir vessel 10 is formed. Further, the delivery hole 5d is connected to the oil reservoir vessel 10, and oil contained in delivery gas is separated in the oil reservoir vessel 10. In this way, a stator can be prevented from its burning by improving cooling of the electric motor 3, and oil can be surely supplied to a bearing by decreasing oil shortage.

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 more particularly to an oil supply device for a bearing portion of a hermetic scroll compressor in which an electric motor section is used as a suction pressure and an intermediate pressure is applied to the rear surface of an orbiting scroll. ..

[0002]

2. Description of the Related Art The oil supply structure of a hermetic scroll compressor is described in JP-A-57-76201 and JP-A-58-214690. Conventionally, in the oil supply method of this type of hermetic scroll compressor, oil is stored in the lower part of the hermetic container and the oil is supplied through an oil supply hole provided in the drive shaft. Further, the electric motor is provided in the lower part, and the discharge connecting portion is provided in the space between the compressor groove and the electric motor, and the refrigerant gas is sucked through the suction port of the fixed scroll, and the electric motor is cooled by the discharge gas.

[0003]

In the above-mentioned prior art, since oil is stored in the lower part of the electric motor, forming occurs when the discharge pressure decreases when the amount of oil is large or the refrigerant is dissolved in the oil. In this case, since the rotor agitates the oil to increase the power and supplies the foamed oil to the bearing, there is a problem that the amount of oil required for the bearing cannot be secured. Further, since the oil is discharged from the discharge connecting portion when the discharge connecting portion is provided in the lower part of the electric motor, it is provided in the space between the compressor groove portion and the electric motor. On the other hand, the electric motor is cooled by the discharge gas, and the lower part of the electric motor is not cooled unless the speed of the discharge gas flowing from the compressor groove portion to the electric motor is increased. However, when the discharge gas velocity is increased, there is a problem that the oil in the discharge gas is not separated and is discharged together with the discharge gas from the discharge connection portion, and the oil in the compressor is lost, so that the bearing seizes.

Further, when a plurality of compressors are installed and the suction pipes and the discharge pipes of the compressors are one, an oil equalizing pipe connecting between the lower parts of the compressors is provided in order to secure oil for each compressor. However, there is a problem that a pressure difference occurs between the bottoms of the compressors, oil cannot be leveled, the oil in the compressor moves, the required oil is not secured, and the bearings are not supplied with oil and the bearings burn out. there were.

An object of the present invention is to improve cooling of an electric motor to prevent burnout of a stator, to prevent oil agitation by a rotor to prevent power from increasing, and to prevent oil from increasing without increasing the size of a hermetic container. An object of the present invention is to provide an oil supply device that reliably supplies oil to a bearing by reducing the amount of oil. In addition, a similar lubrication device is provided even when a plurality of compressors are used, but in particular, to ensure lubrication, for example, when one is stopped and one is operating, stop from the oil sump. It prevents the flow to the compressor inside and allows the compressor to start when it is stopped.

[0006]

To achieve the above object, the present invention comprises a base plate and a spiral wrap integral with the base plate, and a fixed scroll and an orbiting scroll in which both wraps are arranged in mesh with each other. A rotation preventing member that allows the orbiting scroll to rotate without rotating with respect to the fixed scroll, a drive shaft for orbitally driving the orbiting scroll with respect to the fixed scroll, and a compressor groove portion including a frame that supports the drive shaft, and the like. In a hermetic scroll compressor provided with an electric motor for driving the same in a hermetic container, a base plate of the orbiting scroll is slidably held between a base plate of the fixed scroll and the frame, and is provided on a back surface of the orbiting scroll. Is equipped with an intermediate pressure chamber at an intermediate pressure between the suction pressure and the discharge pressure, sets the electric motor section at the suction pressure state, and discharges the fixed scroll. The provided oil reservoir vessel separate communicating,
An oil passage was formed to supply oil from the oil sump container to the compressor groove with a differential pressure.

[0007]

The suction gas is introduced into the closed container from the suction connection portion provided in the closed container, cools the electric motor, and then is sucked through the suction port of the compressor groove and discharged through the discharge hole of the fixed scroll. The discharge hole and the oil sump container communicate with each other, and the oil contained in the discharge gas is separated in the oil sump container.

On the other hand, the both end surfaces of the drive shaft are at the suction pressure, and the end surfaces of the bearings provided on the orbiting scroll and the frame are at the intermediate pressure or the suction pressure, which is the discharge pressure in the oil sump container. The oil in the state is supplied to the bearing due to the differential pressure.

When one compressor or a plurality of compressors are connected to a separate oil sump for simultaneous operation and stop, these actions feed oil to the bearings of the compressor. 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 compressor discharge part and the oil sump piping, and the compressor is stopped. Prevent the discharge gas from flowing backward. Also, if the compressor that is stopped is filled with oil from the oil sump, the swirl scroll and fixed scroll spirals will be filled with oil, making it impossible to start due to liquid compression, so connect the oil sump and the compressor. A solenoid valve is provided in the middle of the refueling pipe to prevent refueling of the compressor that is not in operation.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 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 forming a crank shaft driven by an electric motor 3, a frame 7, and a rotation preventing mechanism 8.

The orbiting scroll 4 has a spiral wrap 4b on a base plate (end plate) 4a. A bearing 4c into which the crank pin portion 6a of the drive shaft 6 is inserted is provided on the back surface of the base plate 4a. In addition, the base plate 4a has a wrap 4b being compressed.
A pressure equalizing hole 4d is provided to connect the space and the back pressure chamber 7c. In addition, the base plate 4a has an opening at the suction pressure portion,
Pressure equalizing hole 4e communicating with the end of the drive shaft 6 on the orbiting scroll side
Are formed.

Fixed scroll 5 fixed to frame 7
Also has a spiral wrap 5b on the base plate 5a.

A suction hole 5c is provided at the outer peripheral portion of the wrap, and a discharge hole 5d is provided at the central portion of the wrap.

The frame 7 fixed to the container 1 has bearings 7a, 7a 'for supporting the drive shaft 6, a base 7b for holding the orbiting scroll 4 with the fixed scroll 5, and an appropriate pressing force for the orbiting scroll 4. A back pressure chamber 7c for giving 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 5 and the pedestal 7b of the frame 7. A rotation prevention mechanism 8 for preventing rotation of the orbiting scroll is installed between the back surface of the orbiting scroll and the frame.

The drive shaft 6 has a crank pin 6a whose one end is supported by a bearing 4c. In addition, the inside of the drive shaft 6 is provided with
b is provided on the center of rotation of the drive shaft 6.

The end face of the oil supply hole 6b on the crank pin 6a side is closed, and is opened to the bearing 7a 'through the oil supply hole 6c. Further, the bearing 4c is opened through the oil supply hole 6d.

The discharge hole 5d of the fixed scroll 5 is communicated with the oil sump container 10 by a discharge pipe 11. Further, the base plate 5a of the fixed scroll 5 has an oil supply hole 5e communicating with the oil sump container 10 via an oil supply pipe 12, and an oil supply hole 5e.
An oil supply hole 5f that is open to a portion where the base plate 4a of the orbiting scroll 4 and the fixed scroll 5 slide with each other is provided. Also, the base plate 4a of the orbiting scroll 4 and the bearing 4
Inside the insertion boss portion 4f of c, an oil supply hole 4h communicating with the inner surface groove 4g of the bearing 4c and the oil supply hole 6d in the drive shaft 6 is provided. Further, in the sliding portion of the base plate 4a of the orbiting scroll 4 with the fixed scroll 5, the oil supply hole 4h and the fixed scroll 5 are provided.
An oil supply hole 4i that communicates with the internal oil supply hole 5f is provided. During the orbiting movement of the orbiting scroll 4, the oil supply holes 4i and 5f are always communicated with each other.

A space 9 containing the electric motor 3 of the closed container 1
A suction pipe 13 is provided in the.

Next, the operation of the scroll compressor will be described. When the drive shaft 6 is rotated by the electric motor 3, the orbiting scroll 4 makes an orbiting motion without rotating due to the rotational motion of the crankpin 6a and the action of the rotation preventing mechanism 8.
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 suction gas sucked from the suction pipe 13 is moved to the electric motor 3 After being cooled, the gas sucked through the suction hole 5c of the fixed scroll 5 through the passage 14 formed between the frame 7 and the closed container 1 is compressed and discharged through the discharge hole 5d. The discharged gas is the discharge pipe 11
After being guided to the oil sump container 10 by separating the oil from the gas, it is discharged from the discharge pipe 16 through the check valve 15. The separated oil accumulates below the oil sump container. When the scroll performs a compression action, a force for separating the orbiting scroll 4 and the fixed scroll 5 acts. Therefore, in order to prevent this, the pressure in the back pressure chamber 7c on the back surface of the orbiting scroll is adjusted by the pressure equalizing hole 4d. , Pressure lower than discharge pressure of each compressor and higher than suction pressure of each compressor (intermediate pressure)
Kept in.

One end of the bearing 4c provided on the orbiting scroll 4 is opened to the back pressure chamber 7c, and the other end communicates with the end surface of the drive shaft 6 and the space formed by the orbiting scroll 4, and the space is a pressure equalizing hole 4e. Is the suction pressure. Also, the bearing 4c
An oil groove slit, for example, may be provided on the surface of the crank pin 6a that slides to adjust the amount of oil. The oil groove slit may be provided on the inner surface of the bearing 4c, the crank pin, or both.

Since the bearing 4c provided on the orbiting scroll 4 has the suction pressure at one end and the intermediate pressure at the other end, the oil in the discharge pressure state at the lower portion of the oil sump container 10 has a differential pressure between the respective oil supply pipes. After refueling, one is discharged to the suction side through the pressure equalizing hole 4e and the other is discharged to the back pressure chamber 7c.

Similarly, the electric motor 3 side bearing 7a 'provided on the frame 7 has one end communicating with the back pressure chamber 7c and the other end having a suction pressure, so that the oil supply holes 6d, 6b, 6c in the drive shaft are formed. Is refueled at each differential pressure via, and after refueling, one is
The back pressure chamber 7c is discharged to the back pressure chamber 7c, and the other is discharged to the space 9 including the electric motor 3.

The above is the description of the method for refueling a single compressor. However, when operating and stopping a plurality of compressors at the same time, the oil sump container and the plurality of compressors are connected by the discharge pipe 17 and the oil supply pipe 18. It is possible to supply oil to the bearings of each compressor by connecting them.

FIG. 2 shows an oil supply system diagram when a plurality of compressors 19 shown in FIG. 1 are respectively operated and stopped. Each discharge pipe 17 is connected via a check valve 20 to the compressor 1 and the oil sump container 1.
0 is connected, and the discharge gas does not flow backward to the stopped compressor from the operating compressor. Further, the oil supply pipe 18 connects the compressor and the oil sump container via an electromagnetic valve 21, and each of the electromagnetic valves is connected so that the compressor in operation is not oiled and the compressor in stop is not oiled. Is open or closed.

Next, another embodiment will be described with reference to FIGS.

FIG. 3 shows a frame 23 and a frame 23 in the oil supply hole 22a provided in the oil sump container 10 and the drive shaft 22.
Oil passage communicating through a bearing 23a provided on the electric motor 3 side
Forming 23b. A circumferential groove 23c and a spiral groove 23d are formed on the inner surface of the bearing 23a.

In the drive shaft 22, the oil supply hole 22b is provided in the drive shaft 22.
It is provided on the center of rotation. This oil supply hole 22b is
The end surface on the crank pin 22c side is closed, and the oil supply hole
It is opened to the bearing 23a via 22a. Further, the bearing 24a is opened through the oil supply hole 22d.

The bearing 2 into which the crank pin portion 22c of the drive shaft 22 is inserted on the back surface of the base plate 24b of the orbiting scroll 24.
4a is provided, and the base plate 24b is provided with a pressure equalizing hole 24c that communicates the space of the lap being compressed with the back pressure chamber 23e. A circumferential groove 24d and a spiral groove 24e are formed on the inner surface of the bearing 24a. Further, in the base plate 24b, a pressure equalizing hole 24f that opens to the suction pressure portion and communicates with the end portion of the drive shaft 22 on the orbiting scroll side is formed.

As described above, one end of the bearing 24a provided on the orbiting scroll 24 on the orbiting scroll 24 side is the suction pressure,
Since the other end has an intermediate pressure, the oil in the discharge pressure state in the lower portion of the oil sump container 10 is supplied at each differential pressure.

Similarly, since the electric motor 3 side bearing 23a provided on the frame 23 has the suction pressure at the electric motor 3 side end surface and the intermediate pressure at the other end, it is supplied with a pressure difference from the discharge pressure.

In FIG. 4, an oil passage 25b is formed which connects the oil reservoir 10 and the inner surface of the bearing 25a provided on the electric motor 3 side of the frame 25 via the frame 25. A circumferential groove 25c and a spiral groove 25d are formed on the inner surface of the bearing 25a.

In the drive shaft 26, oil supply holes 26a are provided on the center of rotation of the shaft 26 with both ends open. As a result, the end surface of the drive shaft on the side of the orbiting scroll 27 is brought into a suction pressure state.

The bearing 2 into which the crank pin portion 26b of the drive shaft 26 is inserted on the back surface of the base plate 27a of the orbiting scroll 27.
7b is provided, and the base plate 27a is provided with a pressure equalizing hole 27c that connects the space of the lap being compressed and the back pressure chamber 25c. A spiral groove 27d that opens to the back pressure chamber 25c is formed on the inner surface of the bearing 27b.

As described above, since the electric motor 3 side end surface of the electric motor 3 side bearing 25a of the frame 25 has the suction pressure and the other end has the intermediate pressure, the oil in the discharge pressure state in the lower portion of the oil sump container 10 is
Refueled with differential pressure. One is discharged to the space containing the electric motor 3, and the other is guided to the back pressure chamber.

The bearing 27b provided on the orbiting scroll 27 is supplied with oil by the differential pressure between the intermediate pressure and the suction pressure,
The oil is discharged from the oil supply hole 26a in the drive shaft 26 to the space including the electric motor 3.

Although FIGS. 3 and 4 have described the method of refueling a single compressor, a plurality of compressors may be installed as shown in FIG. This example is shown in FIGS. 5 and 6. 5 shows a compressor 28 of FIG. 3, and FIG. 6 shows an oil supply system diagram when a plurality of compressors 29 of FIG. 4 are arranged.

Further, all of the above-mentioned explanatory views have explained 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, but the drive shaft is arranged horizontally in the hermetic container. The present invention can be easily applied to a so-called horizontal scroll compressor.

[0040]

According to the present invention, the cooling of the electric motor is efficiently performed by the intake gas.

Further, since the oil in the closed container is transferred to the separate oil sump container together with the discharge gas, the electric motor is not immersed in the oil, and the power is not increased by stirring the oil.

Further, since the oil in the discharge gas is separated by the separate oil sump container, the amount of oil rising to the cycle is reduced and the lubrication of the sliding portion of the compressor is ensured. Further, when using a plurality of compressors, it is possible to reliably supply oil to the sliding parts of the operating compressors even if the capacities or operating speeds of the compressors differ.

[Brief description of drawings]

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

FIG. 2 is an oil supply system diagram when a plurality of compressors shown in FIG. 1 are arranged.

FIG. 3 is a sectional view of a vertical hermetic scroll compressor according to another embodiment.

FIG. 4 is a sectional view of a vertical hermetic scroll compressor according to another embodiment.

FIG. 5 is an oil supply system diagram when a plurality of compressors in FIG. 3 are arranged.

6 is an oil supply system diagram when a plurality of compressors in FIG. 4 are arranged.

[Explanation of symbols]

1 ... airtight container, 2 ... scroll compression mechanism, 3 ... electric motor,
4 ... Orbiting scroll, 4c, 7a '... Bearings, 4d, 4e
... Pressure equalizing holes 4h, 4i, 5e, 5f, 6b, 6c, 6d
... Oil supply hole, 5 ... Fixed scroll, 6 ... Drive shaft, 7 ... Frame, 7c ... Back pressure chamber, 8 ... Rotation preventing mechanism, 9 ... Space, 1
0 ... Oil container, 11, 16 ... Discharge pipe, 12 ... Oil supply pipe, 13 ... Suction pipe, 14 ... Passage, 15 ... Check valve.

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

Claims (1)

[Claims] 1. A fixed scroll and an orbiting scroll, each of which comprises a base plate and a spiral wrap integral with the base plate, and both wraps are arranged in mesh with each other. A rotation preventing member, a drive shaft for orbiting the orbiting scroll with respect to the fixed scroll, a compressor groove portion including a frame supporting the drive shaft, and a motor for driving the compressor groove portion are hermetically sealed. In the hermetic scroll compressor provided inside, the base plate of the orbiting scroll is slidably held between the base plate of the fixed scroll and the frame, and suction pressure and discharge pressure are provided on the back surface of the orbiting scroll. An oil sump provided with an intermediate pressure chamber having an intermediate pressure, the electric motor section being in the suction pressure state, and communicating with the discharge port of the fixed scroll. Vessel and provided, fueling device of the sealed type scroll compressor, which comprises fueling to the compressor groove of the oil sump from the container in differential pressure.