JPH02227583A - Scroll compressor - Google Patents

Abstract

PURPOSE:To prevent counterflow of non-compressive gas back to a compression chamber by inserting a shaft, which is coupled with a revolving scroll and provided with a discharge hole in the axial direction, into the middle of a shaft hole of a motor rotor, and furnishing a check valve in the space over the end face of this shaft. CONSTITUTION:A scroll compressor has a compression part 4 consisting of a revolving scroll 8 and a stationary scroll 6, wherein their laps 6a, 8a are combined together and an arch-shaped compression chamber 9 is formed in between. The bottom eccentric part 11a of a shaft 11 provided with a discharge hole 13 in the axial direction is fitted on a boss 8b provided protruding in the upper part of the revolving scroll 8. Therein a shaft hole 28 is formed in rotor 27 constituting a motor 5 to drive the compression part 4, and the shaft 11 is inserted into the middle of this shaft hole 28. The lower part of an air/liquid separator 30 is fitted in the space 29 bounded by the top surface of shaft 1 and the shaft hole 28, while a check valve 33 is interposed between the air/liquid separator 30 and the shaft 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a scroll compressor that has an improved discharge method for compressed gas compressed in a compression chamber of a compression section.

(Prior technology) Compared to normally used reciprocating compressors and rotary compressors, there is less compression leakage during compression and high efficiency, small torque fluctuations, low vibration and low noise, and suction Scroll compressors are attracting attention because they do not require valves and are highly reliable without problems such as fluid loss or damage caused by valves.

This type of compressor has a compression section at the top inside the sealed case.
Generally, an electric motor is placed at the bottom of this compression section.
High temperature compressed in the compression chamber of the compression section.

High-pressure compressed gas is discharged into, for example, a sealed case through a discharge hole provided in a fixed scroll (case-inside high-pressure type).

By the way, in such a scroll compressor, if the compression part is provided in the lower part of the closed case and is immersed in lubricating oil at the bottom, when the compressed gas is discharged in the above-mentioned method, it may be discharged into the oil. This causes problems such as the oil being blown out or the temperature of the oil being excessively raised due to the heat of the compressed gas.

Therefore, a discharge hole is bored in the boss part of the orbiting scroll and the shaft engaged with this boss part, and the compressed gas compressed in the compression chamber of the compression part is discharged above the oil level through the discharge hole. structure has been adopted.

(Problems to be Solved by the Invention) In the case of an in-case high-pressure type scroll compressor, immediately after the operation is stopped, the inside of the closed case becomes in a higher pressure state than the compression chamber. Therefore, in conventional scroll compressors that simply discharge the compressed gas upward through the discharge hole provided in the boss and shaft of the orbiting scroll, the compressed gas in the sealed case enters the compression chamber through the discharge hole. A phenomenon occurs in which the flow backs up and the mechanical parts are reversed.

This reversal phenomenon of the mechanical part continues until the pressure difference between the inside of the sealed case and the inside of the compression chamber disappears and the pressures of both are balanced.

In addition, separation of the oil component of the compressed gas discharged from the compression chamber of the compression section has not been established, and a large amount of lubricating oil is discharged to the refrigeration cycle together with the compressed gas.
There was a problem of low reliability due to insufficient oil supply to the sliding parts.

Furthermore, during operation, the electric motor that drives the compression section continues to heat up, resulting in deterioration of the operating characteristics of the electric motor and poor operating efficiency.

The present invention was made in view of the above circumstances, and its purpose is to prevent the reverse phenomenon of mechanical parts by reducing as much as possible the amount of compressed gas flowing back into the compression chamber, and to prevent oil discharge into the refrigeration cycle. It is an object of the present invention to provide a scroll compressor that can constantly and stably supply oil to sliding parts by reducing the amount of oil, and can further improve operating efficiency by cooling an electric motor.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, in the scroll compressor of the present invention, the other end of the shaft is inserted up to the middle of the shaft hole of the rotor, and the other end surface of the shaft and the rotor are A check valve is provided in the space formed by the shaft hole.

Alternatively, a space may be formed between the first discharge hole provided in the boss portion of one scroll member and the second discharge hole provided in the shaft, and a check valve may be provided in this space. good.

Furthermore, in the case where the compressed gas compressed in the compression chamber of the compression section is discharged through the discharge hole and the discharge muffler formed in the boss section of the other scroll member, a check valve is installed in the discharge muffler. You can also do this.

(Function) In a scroll compressor with such a configuration, if the pressure inside the sealed case (or inside the discharge muffler) rises higher than the pressure inside the compression chamber immediately after the operation is stopped, the pressure difference causes the check valve to close to one side (or The discharge hole provided in the boss portion of the scroll member (on the other hand) is closed, thereby preventing the compressed gas from flowing back into the compression chamber.

In addition, the compressed gas containing oil is separated into oil and gas by the centrifugal force caused by the rotation of the shaft, and the oil is returned to the bottom of the sealed case, while the gas passes through an electric motor and is heated to its heated state. After cooling an electric motor, it is discharged into the refrigeration cycle.

(Example) Hereinafter, a first example of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 shows the internal structure of a scroll compressor (high pressure type in a case) according to the present invention, and 1 is a closed case.

A frame 2 is fixed to the lower part of the sealed case 1 via a fixing plate 3, and a compressor 4 is provided at the lower part of the frame 2, and an electric motor 5 is provided at the upper part.

The compression section 4 includes a fixed scroll 6 fixed to the lower surface of the frame 2 and a concave space 7 formed on the lower surface of the frame 2.
An orbiting scroll 8 provided between the fixed scroll 6
It consists of Each scroll 6.8 laps 6 a s
8a are overlapped with each other, and these wraps 6a
, 8a is formed with a crescent-shaped compression chamber 9. A suction vibrator 10 is press-fitted into the outer periphery of the fixed scroll 6, passing through the sealed case 1 and communicating with the compression chamber 9. A boss portion 8b projects from the upper surface of the orbiting scroll 8, and an eccentric portion 11a formed at the lower end of the shaft 11 is fitted into the boss portion 8b. The shaft 11 is pivotally supported by a bearing portion 2a of the frame 2. Orbiting scroll 8
A first discharge hole 12 communicating with the compression chamber 9 is bored in the boss portion 8b, and a second discharge hole 13 communicating with the first discharge hole 12 is bored in the shaft 11. has been done. In addition, in the concave space 7 of the frame 2, there is an annular thrust receiver 14 that receives the thrust load of the orbiting scroll 8.
In addition, an Oldham ring 15 is provided to prevent rotation of the orbiting scroll 8, and a balancer 16 is fixed to the eccentric portion 11a of the shaft 11. Furthermore, a first oil hole 17 is bored in the frame 2, and the first oil hole 17 has an annular first oil groove 18, a first and a second spiral groove 19, and a first oil groove 18, a first oil groove 18, a first spiral groove 19, a first oil groove 18, a first oil groove 18, a first oil groove 18, a first oil groove 18, a first oil groove 18, a first oil groove 18, a first oil groove 18, a first oil groove 18, a first oil groove 18, a second spiral groove 19, a second spiral groove 19. 2
0, the second oil groove 21, the second oil passage hole 22, the third spiral groove 23, the concave space 7, and the third oil passage hole 24, in this order. Lubricating oil 25 is stored at the inner bottom of the sealed case 1, and the oil level is maintained at a level above the first oil passage hole 17.

Further, the electric motor 5 includes a cylindrical stator 26 fixed to the inner wall surface of the sealed case 1 and a rotor 27 provided inside the stator 26.

The rotor 27 has a shaft hole 28 into which the upper portion of the shaft 11 is fitted. In this case, the upper end of the shaft 11 is inserted halfway into the shaft hole 28,
A lower part of the gas-liquid separator 30 is fitted and fixed in a space 29 formed by the upper end surface of the shaft 11 and the shaft hole 28 of the rotor 27. The gas-liquid separator 30 has a lower end open and an upper end closed, and is attached to the upper end surface of the shaft 11 with an appropriate distance therebetween. Gas-liquid separator 3
A plurality of discharge holes 31 are bored in the upper part of 0, and a disk 32 is attached to the upper part of the discharge holes 31.

The upper end surface of the shaft 11 and the shaft hole 28 of the rotor 27
A check valve 33 is installed between the gas-liquid separator 30 and the shaft 11 in the space 29 formed by the above. This check valve 33
is formed in the shape of a cross as shown in FIG. The diameter including the projecting piece portion 33b is larger than the inner diameter of the gas-liquid separator 30.

Note that a discharge vibrator 34 is provided on the upper surface of the sealed case 1 so as to open into the sealed case 1.

Next, the operation of the above configuration will be explained.

First, by energizing the electric motor 5, the shaft 11 is rotated and the orbiting scroll 8 is rotated.

Then, the compression chamber 9 is gradually contracted toward the center, and refrigerant gas is sucked in from the suction vibrator 10 and compressed. The refrigerant gas compressed in the compression chamber 9 passes through the first discharge hole 12 of the orbiting scroll 8 and the second discharge hole 13 of the shaft 11.
The discharge pressure pushed up the check valve 33 (in the state shown in FIG. The oil and gas components mixed in the compression chamber 9 etc. are separated by the centrifugal force caused by the rotation of the , the oil component drops into the inner bottom of the sealed case 1 through the gap in the electric motor 5, and the gas component passes through the discharge vibrator 34 to the refrigeration cycle. It is discharged to.

By the way, in the case of an in-case high-pressure scroll compressor, when the operation is stopped, the pressure inside the closed case 1 becomes higher than that inside the compression chamber 9, and the refrigerant gas inside the closed case 1 flows through the second shaft of the shaft 11. There have been cases where the liquid flows back into the compression chamber 9 through the discharge hole 13 and the first discharge hole 12 of the orbiting scroll 8, causing a phenomenon in which the mechanical part is reversed.

Therefore, in this embodiment, the upper end surface of the shaft 11 and the rotor 2
Since a check valve 33 is installed between the gas-liquid separator 30 and the shaft 11 in the space 29 formed by the shaft hole 28 of 7, the pressure inside the sealed case 1 is equal to the pressure inside the compression chamber 9 immediately after the operation is stopped. , the check valve 33 seats on the upper end surface of the shaft 11 due to the pressure difference, and the central portion 3 of the check valve 33 seats on the upper end surface of the shaft 11.
3a closes the second discharge hole 13 (as shown in FIG. 3). This prevents the refrigerant gas from flowing back into the compression chamber 9, and minimizes the amount of refrigerant gas flowing back into the compression chamber 9. Therefore, it is possible to reliably prevent the mechanical part from reversing.

Further, the refrigerant gas discharged from the compression chamber 9 of the compression section 4 is separated into oil and gas by the disk 32 of the gas-liquid separator 30, and only the gas component is discharged to the refrigeration cycle. The amount of oil discharged is reduced, and the sliding parts can always be reliably lubricated.

Furthermore, the upper end surface of the shaft 11 and the shaft hole 28 of the rotor 27
Since the check valve 33 is installed between the gas-liquid separator 30 and the shaft 11 by using the space 29 formed by , it does not involve a significant increase in the number of parts and can be manufactured at low cost. Furthermore, since the check valve 33 is housed inside the space 29, it is small and lightweight, and there is little noise caused by the check valve 33.

FIG. 4 shows a second embodiment of the invention. Note that although the scroll compressor of this embodiment is a double-blade movable type, its basic configuration is the same as that of the single-blade movable type shown in the first embodiment. The reference numerals are given and the explanation thereof is omitted, and only the parts related to the present invention will be explained.

In the figure, a fitting recess 41 is formed at the lower end of the shaft 11, and a boss portion 42a of a first movable scroll 42 is integrally fixed to the fitting recess 41 by press fitting, shrink fitting, etc. . A first discharge hole 12 is bored in the boss 42a of the first movable scroll 42. The length of the fitting recess 41 is longer than the boss 42a of the first movable scroll 42, and the check valve 33 is installed in the space 43 formed by the upper end surface of the boss 42a and the fitting recess 41. has been done. The shaft 11 is formed with a discharge vertical hole 44 that communicates with the fitting recess 41 and has a smaller diameter than the fitting recess 41. A discharge horizontal hole 45 is bored.

In the scroll compressor having such a configuration, the compression section 4
The refrigerant gas compressed in the compression chamber passes through the first discharge hole 12 of the first movable scroll 42, and the discharge pressure closes the check valve 3.
3 is pushed up, the fluid passes through the space 43, the vertical discharge hole 44, and the horizontal discharge hole 45 in order and is discharged between the electric motor 5 and the compression section 4. At this time, the refrigerant gas receives centrifugal force due to the rotation of the shaft 11, and is separated into oil and gas. The oil passes through the gap in the compression part 4 and drips onto the bottom of the sealed case, and the gas passes through the gap in the motor 5 to cool the motor 5, and then enters the refrigeration cycle through a discharge pipe provided on the top of the sealed case. It is discharged. Immediately after the operation is stopped, when the pressure inside the sealed case 1 rises higher than the pressure inside the compression chamber, the check valve 33 is seated on the upper end surface of the first movable scroll 42 due to the pressure difference, and the check valve 33 is Central part 33a
to close the first discharge hole 12. Therefore, as in the first embodiment, the refrigerant gas is prevented from flowing back into the compression chamber, thereby preventing the mechanical part from reversing.

In addition, as in the first embodiment, the refrigerant gas can be forcibly centrifuged into oil and gas, reducing the amount of oil discharged into the refrigeration cycle and ensuring stable oil supply to sliding parts. .

Furthermore, the electric motor 5 is cooled by the refrigerant gas from which oil has been separated, thereby preventing the electric motor 5 from overheating and improving its operating characteristics.

FIG. 5 shows a third embodiment of the invention. This embodiment is applied to a scroll compressor of a low-pressure type inside the case and with movable wings.

In this case, the compression part 4 is provided in the upper part of the sealed case 1,
An electric motor 5 is provided below the compression section 4. A boss portion 51a of a second movable scroll 51 is pivotally supported by the second bearing portion 2b of the frame 2, and a first discharge hole 12 is bored in the boss portion 51a. A discharge muffler 52 is fitted onto the second bearing portion 2b of the frame 2, and the discharge muffler 52 is disposed on the upper surface of the discharge muffler 52.
A positioning recess 53 is formed to protrude into the positioning recess 53, and a plurality of discharge holes 31 are bored at the outer periphery of the positioning recess 53.

A check valve 33 is provided within the discharge muffler 52. Note that the first movable scroll 42 has a shaft 1.
1 are connected to each other, and this shaft 11 rotates a first movable scroll 42 and a second movable scroll 51. Other basic configurations are the same as those of the second embodiment.

In the scroll compressor having such a configuration, the compression section 4
The refrigerant gas compressed in the compression chamber 9 passes through the first discharge hole 12 of the second movable scroll 51, and its discharge pressure pushes up the check valve 33 and muffles the sound within the discharge muffler 52, reducing discharge pressure pulsations. Thereafter, it is once discharged from the discharge hole 31 into the discharge space 54 partitioned by the frame 2, and further discharged into the refrigeration cycle through the discharge vibrator 34. Immediately after the operation is stopped, when the pressure in the discharge space 54 rises higher than the pressure in the compression chamber 9, the check valve 33 is seated on the upper end surface of the second movable scroll 51 due to the pressure difference, and the check valve 33 is seated on the upper end surface of the second movable scroll 51. The central portion 33a of the valve 33 opens the first discharge hole 12.
occlude. Therefore, as in the first embodiment, the refrigerant gas is prevented from flowing back into the compression chamber 9, and the reverse phenomenon of the mechanical part can be prevented.

〔Effect of the invention〕

As explained above, according to the present invention, since the check valve is provided in the middle of the discharge hole that communicates the compression chamber of the compression section with the inside of the closed case (or inside the discharge muffler), immediately after the operation is stopped, the closed case If the pressure inside (or inside the discharge muffler) rises above the pressure inside the compression chamber, the amount of compressed gas flowing back into the compression chamber can be kept to a minimum, and reversal of the mechanical part can be reliably prevented. Furthermore, since the compressed gas can be forcibly centrifuged into oil and gas, the amount of oil discharged into the refrigeration cycle is reduced, and the sliding parts can always be reliably supplied with oil. Furthermore, the motor is cooled by the compressed gas from which oil has been separated, thereby preventing the motor from overheating and improving its operating characteristics.

As described above, it is possible to provide a scroll compressor with good reliability and operational efficiency.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, FIG. 1 is a longitudinal cross-sectional side view of a scroll compressor of a high pressure type inside a case and a single cloud movable type, and FIG. 2 shows a check valve and its FIG. 3 is a plan view of the surrounding area, FIG. 3 is a vertical cross-sectional side view of the main part, and FIG. 4 is a vertical cross-sectional side view of the main part of an in-case high-pressure type scroll compressor with two movable wings, showing a second embodiment of the present invention. Figure, 5th
The figure is a longitudinal sectional side view of a main part of a scroll compressor of a case-internal low-pressure type and of a dual-blade movable type, showing a third embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Airtight case, 4... Compression part, 5... Electric motor, 6... Fixed scroll, 8... Orbiting scroll,
8b... Boss portion, 9... Compression chamber, 11... Shaft, 12... First discharge hole, 13... Second discharge hole, 26... Stator, 27... Rotor, 28...
Shaft hole, 29.43... Space, 33... Check valve, 4
2...First movable scroll, 42a...Boss part,
44...Discharge vertical hole, 45...Discharge horizontal hole, 51...
Second movable scroll, 51a... Boss portion, 52...
・Discharge muffler. Applicant's agent Patent attorney Takehiko Suzue 2 Figure

Claims (3)

[Claims] (1) A compression part and an electric motor are provided in a sealed case, and the compression part is formed by meshing a pair of scroll members to form a compression chamber and connecting one end of a shaft to the boss part of one scroll member. A rotor is provided inside the stator, and the other end of the shaft is inserted into the shaft hole of the rotor, and the compressed gas compressed in the compression chamber of the compression section is transferred to the boss part of the one scroll member and the shaft. In a scroll compressor that discharges air through a discharge hole drilled in the rotor, the other end of the shaft is inserted halfway through the shaft hole of the rotor, and a space formed by the other end surface of the shaft and the shaft hole of the rotor is formed. A scroll compressor characterized by being equipped with a check valve. (2) A space is formed between the first discharge hole provided in the boss portion of one scroll member and the second discharge hole provided in the shaft, and a check valve is provided in this space. The scroll compressor according to claim 1. (3) A compression section and an electric motor are provided in a sealed case, and the compression section is formed by meshing a pair of scroll members to form a compression chamber and connecting one end of a shaft to the boss section of one scroll member. A rotor is provided inside the stator, and the other end of the shaft is inserted into the shaft hole of the rotor, and the compressed gas compressed in the compression chamber of the compression section is passed through the boss part of the other scroll member. A scroll compressor that discharges fluid through a discharge hole and a discharge muffler, characterized in that a check valve is provided in the discharge muffler.