KR100301202B1 - Scroll Compressor with oil control structure - Google Patents

Abstract

The present invention relates to an apparatus for reducing the amount of oil discharged from a scroll compressor, and more particularly, a fixed scroll and a rotating scroll wrap create a compression chamber, and the refrigerant in the process of inhaling, compressing, and discharging the refrigerant by the compression force generated by the relative movement thereof. By changing the flow path of the oil flowing together with the refrigerant discharge step to reduce the amount of oil discharged to solve the problem caused by the lack of oil.

The present invention has a rotating scroll to convert the rotational movement of the main shaft to the rotational movement for the fixed scroll having a scroll wrap and combined with the scroll wrap and the fixed scroll and compresses the compression chamber to compress the refrigerant by the relative movement between the wraps In the scroll compressor having an oil supply flow path between the contact movement surface between each scroll wrap, the flow path so that the oil remaining on the hard disk surface flows from the high pressure side to the low pressure side by installing a capillary tube at an arbitrary position penetrating the turning scroll hard plate surface Will be made. This reduces the amount of oil simply discharged.

Description

Reduction of oil discharge in scroll compressors {Scroll Compressor with oil control structure}

The present invention relates to an apparatus for reducing the amount of oil discharged from a scroll compressor, and more particularly, a fixed scroll and a rotating scroll wrap create a compression chamber, and the refrigerant in the process of inhaling, compressing, and discharging the refrigerant by the compression force generated by the relative movement thereof. By changing the flow path of the oil flowing together with the refrigerant discharge step to reduce the amount of oil discharged to solve the problem caused by the lack of oil.

In general, the scroll compressor is a type of compressor mainly used in air conditioners and freezers because it has excellent dynamic performance in a wide range of capacity compared to other types of compressors.

In addition, since the compression lap constitutes the compression chamber of the compression mechanism, the upper, lower, left, and right sides of the scroll lap show contact motion. Therefore, the wear of the compression chamber is larger than that of other compressors. It is important.

The lubrication of the contact surface on any actuator, as well as the scroll compressor, is provided as a minimum measure to avoid wear and various mechanical defects. The scroll compressor also has a contact surface around the compressor section and the upper and lower support systems of the spindle. It is designed to enable lubrication at. This lubrication system is closely related to the drive system of the scroll compressor and assists in the dynamic movement of each drive system.

The main part of the scroll compressor includes a case 6 having upper and lower caps 4 and 5 to distinguish the discharge chamber 2 and the suction chamber 3 through the upper diaphragm 1 as shown in FIG. Compression chamber in the form of an electric motor 7 and a stator 8 and a main shaft 9, a rotating scroll 10 and a fixed scroll 11 interlocked with the motor mechanism, and protected by the upper diaphragm 1. Compressor spheres forming 12, etc., with the upper part being the discharge chamber 2 and the lower part being the suction chamber 3 centering on the upper diaphragm 1.

In addition, there is a check valve 13 between the upper diaphragm 1 and the fixed scroll 11 that separates the suction chamber 3 and the discharge chamber 2, through which the refrigerant gas compressed in the compression chamber 12 is discharged. (2) or prevent the back flow of gas in the discharge chamber (2).

The pressure distribution in the compressor case 6 during operation is such that the suction chamber 3, which introduces the refrigerant through the suction pipe 14, becomes the low pressure side, and the discharge chamber 2, which flows in through the compression mechanism, is relatively high pressure side. Becomes

The refrigerant flowing through the suction pipe 14 enters the compression chamber 12 of the involute curve wrap formed on the swinging scroll 10 which is driven by the main shaft 9 and the fixed scroll 11 coupled thereto. When the rotor 7 rotates and the main shaft 9 is rotated, the old dam ring 17 on the main frame 15 and the driving bush 16 is rotated with the turning scroll 10 and the one-way key. It is connected to the groove to change the rotational movement of the main shaft (9) to the turning movement of the turning scroll (10), when the turning scroll wrap to form a suction flow path away from the outer wrap of the fixed scroll (11) in the initial position Through this, the introduced refrigerant collects the two half moon compression chambers 12 formed by the two scroll wraps toward the center of the scroll according to the turning angle, and continuously compresses the refrigerant.

Eventually, the compression chamber 12 collected at the center is opened at the discharge port 18 on the rear side of the fixed scroll 11, and the discharged compressed refrigerant gas pushes up the check valve 13 mounted on the fixed scroll 11. It is discharged into the discharge chamber 2 composed of the diaphragm 1 and the upper cap 4, and the refrigerant gas is sent to the refrigeration / air conditioning cycle such as a condenser through the discharge pipe 19.

In the compression chamber 12 formed by the fixed scroll 11 and the revolving scroll 10, the leakage in the radial direction through the gap between the wrap tip of the revolving scroll 10 and the bottom of the fixed scroll 11 is mutually different. There may be a leakage occurring in the tangential direction through the gap between the side portions of the wrap that are connected. Typically, the driving bush 16 may be a slide bush or an eccentric bush to prevent the leakage occurring in the tangential direction between the wrap side portions. Prepared for loss of power due to leakage.

The scroll compressor arranges all the drive systems, that is, the compression mechanism and the power mechanism in the center of the shaft, in order to flow the refrigerant in the order of main shaft rotation, rotation scroll rotation, refrigerant suction, compression, and discharge, which is supported by the support system. The driving system is supported on the case by dividing the upper side and the lower side again.

The upper part of the compression mechanism support system is a type of supporting the pivoting scroll (9) coupled to the fixed scroll (11) and the wrap through the main frame (15) to support the main shaft (9).

There is a thrust surface in which the pivoting scroll 10 and the main frame 15 come into contact with each other, and a slide or eccentric type makes contact with the driving bush 16 fitted to the main shaft 9 and the pivoting scroll 10 coupled thereto. A journal bearing 21 is provided between the surfaces, and the journal bearing 21A is fitted to the contact surface of the main shaft 9 and the main frame 15 so as to reduce the dynamic load of the compressor sphere without the fixed scroll 11 as a whole. The mainframe 15 is received and bearing lubrication between the drive parts.

The lower support system is a portion decorated for supporting the main shaft (9). This is typical of the subframe 22 supporting the main shaft 9 on the inner wall of the case 6, and the journal bearing 21B provided on the contact surface between the main shaft 9 and the subframe 22. As shown in FIG.

In addition to the support system, there is a lubrication system. This part has the supply passage 23 under the main shaft 9 to send oil to the contact motion surface or the compression mechanism, which appears at the center of the main shaft and the support system, and ascends from here, the upper turning scroll 10 of the main shaft 9 It has an eccentric inclined feed passage 24 and several outlets up to the point where it meets), and has an oil pumping system and a return system.

The oil pumping system is centered on the subframe 22, and submerged in the oil level, and includes a supply passage 23 centered on the main shaft 9, and on the main shaft 9 in the subframe 22. A pump plate 25 is placed between the pump roller 25, the pump cover 27 having a flow path 26 for forming a passage in the pump roller 25, and the subframe 22 and the pump cover 27. It is.

The oil return system includes a pivoting scroll (10) coupled to the drive bush (16) and a main frame (15) which is a side outer wall of the space (29) with a slight space (29) at the face of the main frame (15). The oil return hole 30 leading to the suction chamber 3 along the thickness of the and includes a return hole in each support system or oil flow path.

The oil allocation scheme for the drive system and support system during operation has a direction from bottom to top.

That is, when the main shaft 9 is turned, the pump roller 25, which is a volumetric oil supply pump mounted on the subframe 22, rotates and sends oil to the supply passage 23 of the main shaft 9. The oil flowing into the main shaft (9) is continuously introduced by the centrifugal force of the main shaft (9) and is first supplied to the journal bearing (21B) between the subframe (22) and the main shaft (9), and the rest overcomes gravity and flow path resistance. And some of them climb up the inclined supply passage 24 to lubricate the journal bearing 21A on the contact surface of the main shaft 9 and the main frame 15, wherein the lower journal bearing 21B is lubricated. The lubricated oil returns to the oil level 31.

Some of the oil lubricated continuously by the journal bearing 21A lubricates the thrust surface of the mainframe through a lubrication hole, and part of the oil is spaced between the mainframe 15 and the pivot axis of the swinging scroll 10. Supplied.

And the remainder which does not flow into the lubrication hole from the supply hole rises to the end of the main shaft (9) to lubricate the journal bearing (21) between the turning scroll (10) and the driving bush (16), and the rest of the shaft pin portion and the driving portion It enters the space 29 between the sieves 16 and is supplied to the space between the pivoting bearing of the journal bearing 21 and the turning scroll 10 to return to the oil level 31 through the oil return hole 30. The remainder is lubricated thrust bearing 20 and then flows into the compression chamber 12 along the flow path in the compression chamber 12 of the fixed scroll 11 and the turning scroll 10 and is not discharged together with the refrigerant. Return to 31).

In particular, in the refrigerant compression process leading to suction, compression, and discharge of the refrigerant by the relative motion of the fixed scroll 11 and the swinging scroll 10, a considerable amount of oil enters the compression mechanism and is discharged together with the refrigerant. This is achieved by creating an oil path into the compression chamber for the formation of an oil film on the contacting motion in 12) and the sealing between the scroll wraps.

In other words, the oil that once enters the compression chamber of the compression mechanism is discharged together with the refrigerant unless there is any artificial means.

The oil discharge occurs due to the factors of the compression chamber characteristics of the compression mechanism, but the amount varies depending on the operating speed.

For example, in a variable speed scroll compressor in which the operating speed varies by 0.5 to 2 times the rated frequency according to the environment, the oil supply varies according to the operating speed and the frequency band. In the case of the high speed operation, the oil supply amount is increased than the low speed / rated frequency operation, and the amount of oil discharged with the refrigerant in the compressor increases in proportion to the oil supply amount.

Therefore, in the high-speed operation, the amount of oil remaining in the compressor decreases as the amount of oil and the discharge amount increase together, and when the amount of residual oil reaches a low level below the threshold, insufficient oil supply corresponding to the operation speed is not performed properly. This oil supply failure is not enough oil to be sent to each lubrication part and the contact movement surface decorated around the support system, which causes mechanical wear, such as abrasion on the contact movement surface, bearing restraint, or thermal deformation between parts. Defects appear and affect compressor reliability.

This problem is more serious in variable speed scroll compressors, such as refrigeration and air conditioning cycles, which increase and decelerate up to approximately 0.5 to 2 times the rated operating frequency to cope with the operating environment such as indoor and outdoor temperature and target temperature setting.

As the running speed changes, the speed at which the oil pump turns is the same. This fluctuates the oil supply and there is a remarkable difference in oil supply at low speed and high speed operation. At high speeds, the oil supply is also activated and a large amount of oil follows the spindle. The amount of oil discharged is also inextricably linked to the oil supply.

There are several ways to reduce the amount of oil dumped by the discharge.

The operating speed is maintained at the rated frequency band. But in a variable speed scroll compressor, this operation is meaningless.

Sufficient oil supply is maintained at the increase and decrease speed while suppressing the discharge amount similarly to the discharge amount generated at the rated frequency band. This is because the faster the speed of operation, the faster the oil circulation and the more sufficient flow is required. However, control of the discharge amount proportional to the oil supply amount remains a problem.

The other is to maintain the oil supply in proportion to the speed while the suction and compression discharge process in the compression chamber with the refrigerant to recover the discharged oil. For example, a method of recovering the oil discharged from the compression chamber together with the refrigerant to the bottom surface using a mechanism such as a capillary tube toward the lower pressure from the discharge chamber in which the discharge pressure is formed.

However, it is difficult to systematically send the oil in the discharge chamber downward, and there is a burden of having to separately install an additional device dedicated to oil recovery.

In the variable speed scroll compressor, the oil lubrication amount and the discharge amount are proportional to the operation speed, resulting in a loss.

The application of several methods has led to the inevitable application of new devices related to the discharge and control of the discharge volume or lack of sufficient flow required for variable speed scroll compressors.

Setting aside a dedicated discharge chamber or a retrieval device for collecting oil already discharged in the discharge passage has no value beyond a simple attachment irrelevant to the dynamic performance of the compression mechanism and lowers the economy.

However, if there is no oil recovery device in the variable speed scroll compressor, especially in high speed operation, the amount of lubrication and discharge rate increase rapidly, and when the amount reaches the low level beyond the threshold, it is not possible to maintain enough oil level for lubrication. Due to this, mechanical failures such as wear of the contact surface of the drive system, restraint of bearings, or heat deformation between parts may be caused, which affects the performance of the compressor, which leads to a problem of deteriorating reliability.

The present invention is provided by whether the amount of oil discharged according to the operating speed can be reduced economically and reliably.

Therefore, an object of the present invention is to recover the oil from the compression chamber consisting of the scroll scroll of the fixed scroll and the swing scroll in which the oil discharge occurs, without any additional device.

Another object of the present invention is to make the recovery route relatively simple to enter the oil from the compression chamber.

1 is a schematic diagram of a scroll compressor.

2 is a plan view of the capillary structure turning scroll of the present invention.

3 is a capillary structure according to the first embodiment of the present invention,

(A) section,

(B) Part A detailed view of (a).

Figure 4 is a capillary cross-sectional view of a second embodiment of the present invention.

5 is a cross-sectional view of another embodiment of FIG. 4.

6 is a capillary structure according to a third embodiment of the present invention,

(A) is a cross-sectional view,

(B) shows another embodiment.

7 is a view showing another embodiment of the capillary flow path according to the present invention.

*** Explanation of symbols for the main parts of the drawing ***

2: discharge room 3: suction room

6: Case 9: headstock

10: turning scroll 11: fixed scroll

12: Compression chamber 15: Main frame

21.21A.21B: Journal bearing 22: Subframe

23: Supply passage 24: Inclined supply passage

25: pumping roller 27: pump case

29: space 30: oil return hall

31: Cotton 40; Capillary tube

41: oil discharge groove 42: hole

43: Pitch 44: Pin

45: thread groove 46.46 A: groove

A feature of the present invention for achieving this object is a rotating scroll that is converted to the rotational movement of the main shaft with respect to the fixed scroll having a scroll wrap and combined with a scroll wrap and the fixed scroll, and they have a relative A scroll compressor comprising a compression chamber for compressing a refrigerant by movement;

By installing a capillary tube penetrating the hard disk surface of the pivoting scroll central portion is characterized in that the flow path is made so that the oil remaining on the hard disk surface flows from the high pressure side to the low pressure side.

Optionally, the flow path is characterized in that the capillary tube which does not penetrate the hard disk surface of the swinging scroll is installed, and an oil discharge groove communicating with the capillary tube is formed on the thick plate thickness surface of the swinging scroll.

Another feature of the present invention is characterized by forming a flow path corresponding to the screw groove pitch by processing the screw grooves penetrating the hard plate surface of the center portion of the turning scroll and pinned to contact most of the inner diameter of the screw groove.

Optionally, after partially processing the screw grooves that do not penetrate the hard disk surface of the turning scroll, insert a pin contacting the inner diameter of most of the screw grooves to block the screw grooves, and discharge oil in communication with the flow path or gap corresponding to the pitch of the screw grooves. A groove is formed in the hard plate thickness surface of a turning scroll.

Another feature of the present invention is to process the groove in the outer wall of the capillary tube penetrating the hard disk surface of the center portion of the turning scroll, inserting a pin to form a flow path corresponding to the capillary tube on the outer scroll wheel to the back of the low pressure swing scroll from the compression chamber A flow path is formed.

Optionally, the groove is processed in the turning scroll, and a pin corresponding to the groove is inserted therein, and a flow path corresponding to the capillary is formed along the outer wall of the pin.

It is characterized in that the grooves are processed in a range not selectively penetrating the hard disk surface of the turning scroll, and an oil drain passage that meets the flow path corresponding to the capillary is formed on the thick plate thickness surface of the turning scroll.

In this way, if the capillary flow path is placed on the rotating plate of the rotating scroll that makes the compression chamber by the contact between the fixed scroll and the lap, some of the oil passing through the contact movement surface between the scroll laps is lowered to the low pressure side without any additional device, and the amount of oil that escapes from the compression chamber like the refrigerant You can get results that reduce

An embodiment of the present invention will be described with reference to the drawings.

2 is a plane view of the swing scroll. FIG. 3 is a schematic diagram of a capillary flow path provided in a turning scroll, FIG. 4 is another form of the capillary flow path, and FIG. 5 and below show the shapes of different capillary flow paths.

The main part of the embodiment is a flow path through which oil flows in the compression chamber 12 made by the fixed scroll 11 and the revolving scroll 10 and the flow path has a capillary-shaped passage.

This flow path is particularly defined near the center of the turning scroll 10, and may have a separate oil discharge groove 41 that passes through the turning scroll 10 or flows to the low pressure side along the hard plate surface thickness.

That is, the basic form is that the oil flows from the high pressure side to the low pressure side by installing a capillary tube 40 through the hole 42 penetrating the hard plate surface near the center of the turning scroll 10. Structure.

Here, the oil outlet 41 may be processed along the thickness of the turning scroll 10 hard plate to form a flow path connecting the capillary tube 40.

Another embodiment of making the flow path in the form of capillary tube 40 is to modulate the flow into the capillary flow path by adding an object to the flow path that is drilled in the turning scroll 10. A hole of a suitable size is drilled and the inner wall of the hole is machined into a threaded pitch 43 or a hole through which oil can flow, and a pin 44 about the wall surface of these holes is inserted into the hole.

In this case, in the case of the screw groove 45, the outer wall of the pin 44 is in contact with the pitch, and when the wall of the hole 42 is the groove 46, the pin 44 is partially in contact,

Similarly, the oil discharge groove 41 may be processed along the thickness of the turning scroll 10 hard plate to be connected to the hole 42 to form a new path.

In addition, the hole 42 is machined in the turning scroll 10, and the pin 44 corresponding to the hole 42 is inserted, and a flow path corresponding to the capillary tube 40 is formed along the outer wall of the pin 44. Capillary structures are also possible.

In this way, when various capillary flow paths are defined on the hard disk surface of the turning scroll and the oil is discharged downward from the discharge chamber, oil remaining on the hard plate surface of the turning scroll among the oils going to the discharge chamber along with the discharge chamber of the compression chamber It can be quickly sent to the low pressure side oil through the capillary can reduce the amount of oil discharged, the specific action is as follows.

As the main shaft 9 rotates, the turning scroll 10 rotates along, causing a relative movement between the fixed scroll 11 and the lap to compress the refrigerant. At this time, the formation of an oil film on the contact surface between the laps reduces wear and the sealing against radial and tangential leakage all depends on a sufficient oil supply pumped below. Therefore, when the scroll wrap forms the compression chamber, oil is supplied to the compression chamber 12 sufficiently and the compressed refrigerant is sent to the discharge chamber, so the oil comes with the discharged refrigerant in the compression chamber. Of course, the amount of oil escaped during high speed operation in a variable speed scroll compressor is larger. In quantitative terms, it is proportional to the driving speed.

As described above, the application of the additional device for recovering the oil already discharged from the scroll compressor is not suitable and economical in many ways because it has a functionally long flow path. In a variable speed compressor, the absence of an oil recovery device results in greater losses instead. The present invention solves two problems related to such oil recovery.

The oil, which has risen to the compression chamber along the main shaft, finishes the lubrication and sealing between the scroll wraps, and part of the oil is discharged into the discharge chamber together with the refrigerant, and part of the oil is collected on the hard plate surface of the turning scroll 10.

The compression chamber (chamber), which appears as a relative movement of the scroll lap, collects from the outside into the center (Fig. 2. S1) and has a movement that opens again. The oil also flows in the space created by the scroll lap. Therefore, the flow distribution in the turning scroll 10 shows the distribution with the largest center and the smallest outside. Since this region is a portion where the refrigerant gathers and exits to the discharge port 18 of the fixed scroll 11, the oil separated from the refrigerant is also collected and thus will have a higher flow rate distribution. When the capillary tube 40 is installed on the hard plate surface near the center portion S1 of the turning scroll 10 as shown in FIG. 3, the capillary tube 40 is positioned at the largest portion of the oil distribution on the hard plate surface of the turning scroll 10. do.

The capillary tube 40 sucks and compresses from the suction port together with the refrigerant to separate gaseous liquid from the mixed fluid of the refrigerant and oil discharged to the discharge port so that only the oil is discharged to the lower pressure side of the compression chamber 12.

Expecting the role of this capillary 40 appears when several conditions are satisfied.

The inner diameter of the capillary tube 40 should be small enough. That is, the flow resistance must be above a certain threshold. In the flow rate passing through the capillary tube 40, the viscosity of the oil, which changes according to temperature and pressure, acts as an important factor, thereby selecting the viscosity of the oil. Another cause of the flow rate variable is that the refrigerant and the oil form a mixed fluid, so it is necessary to clarify the solubility relationship between the oil and the refrigerant.

In consideration of the various flow rate parameters that oil may have in the capillary, adjusting the oil viscosity or component enables the oil to be discharged by the capillary tube 40.

In particular, the degree of flow resistance of the capillary tube 40 must satisfy the condition that the increase and decrease of the oil discharge amount such as a variable speed scroll compressor is continuous. It is not good to discharge too much oil instantaneously in terms of the compressor's performance characteristics (dynamic). Therefore, the flow resistance through the capillary tube should be more than a certain value in order to discharge the oil in an appropriate amount and not affect the performance characteristics. The flow resistance of the capillary is proportional to the length of the capillary and inversely proportional to the inner diameter. On this basis, if the flow rate variable and the flow path resistance are properly adjusted, there is no problem in the discharge of oil through the capillary tube 40. However, the smaller the inner diameter of the capillary tube has the disadvantage of poor workability and installation.

Machining the capillary tube 40 and the oil discharge groove 41 extending in the orbiting scroll 10 is more advantageous to actually consider the flow resistance. This is because the capillary tube 40 can be properly adjusted to the inner diameter and the oil discharge groove 41 can be made wider to match the flow resistance.

It is more important that the oil does not flow to the low pressure side in any form or when the oil discharge from the hard plate surface of the turning scroll 10 through the capillary tube 40. It is related to flow resistance or flow rate variable, and when this is premised, the oil filling the flow path of the capillary tube 40 is pushed to the low pressure side forcibly by the earth output in the compression chamber 12.

Otherwise, since the oil simply flows down through the capillary tube 40 at low pressure, it is necessary to prepare for the possibility of leakage of the compressed refrigerant along the capillary tube 40 passage through the compression chamber 12.

Substantially, the application of the capillary flow path 40 is sufficient for the discharged refrigerant of the compression chamber 12 to flow back into the suction chamber when the oil fails to fill the capillary flow path in the initial operation of the compressor. However, since the amount is only a small amount compared with the loss represented by the oil loss, it can be regarded as negligible.

According to the capillary flow channel of FIG. 3, the influence on the performance characteristics of the variable speed scroll compressor can be minimized, and at the same time, the increase in the discharge amount due to the increase in the oil supply rate at high speed can be suppressed.

4 is a screw groove capillary.

First of all, this structure is provided to make arithmetic more advantageous to the flow resistance of the ordinary capillary tube of FIG. 3 and to supplement the problems related to workability and installation through tapping.

When tapping the hard plate surface of the turning scroll 10, the inner wall of the processing hole is a screw groove 45 having a pitch 43. When the pin 44 is inserted therein, the pin 44 causes flow path resistance and a limited flow path, that is, a capillary tube 40, is provided along the remaining pitch 43, thereby improving workability. So easy to install. Likewise, the flow path of the oil can be adjusted by extending the capillary flow path to the oil discharge groove 41 without penetrating the screw groove through the turning scroll 10. This will cause the oil accumulated in the hard plate surface of the turning scroll 10 to go down along the valleys of the pitch 43 between the pins 44 and make a long flow path, whereby sufficient flow resistance is obtained. According to the capillary tube 40 using the screw groove 45, the influence on the performance characteristics of the variable-speed scroll compressor can be minimized, and at the same time it is possible to suppress the increase in the discharge amount due to the increase in the oil supply during high-speed rotation.

The method of pumping or discharging the remaining oil is the same as that of FIG. 3.

The capillary tube 40 of FIG. 6 drills a hole 42 in the turning scroll 10 and makes a groove 46 in the wall of the hole to insert a pin 44 to form a capillary tube. Oil flows along this groove 46 to the lower pressure side below.

The capillary tube of FIG. 7 forms a groove 46A in the pin 44 and is inserted into the hole 42 drilled in the turning scroll 10 to form a capillary flow path at a position different from that of FIG. 6, except that the oil discharge path is the same. It can be seen as.

As described above, the various capillary models do not discharge oil collected in the hard disk surface portion of the turning scroll 10 to form the compression chamber together with the refrigerant, but some of the oil provided to the compression chamber is flowed to the low pressure side through the turning scroll without any other artificial device. It has common features.

Ideally, since the oil discharge is centered around the orbiting scroll 10, the provided capillary tube 40 will inevitably create a flow path communicating with the compression chamber 12, so that refrigerant leakage from the compression chamber can be through this capillary tube. Given that, the oil filled in the capillary gradually moves to the low pressure side corresponding to the pressure ratio of the compression chamber.

This can be obtained by taking the optimum flow resistance from the various capillary models provided and considering the flow rate variable.

This eliminates the leakage of the compression chamber through the capillary tube while compensating for the shortage of oil supply due to too much oil discharge.

As described above, the present invention reduces the amount of oil discharged by directly lowering oil to the oil surface by obtaining a new oil return path from the compression chamber, without increasing the amount of oil discharged in accordance with the operating speed in the variable speed scroll compressor without any other artificial factors. Compared to the various devices provided to prevent the loss of reliability of the compressor and recover the oil discharged with the refrigerant, the processability and installation are good, and there are fewer parts, and the effect can be made at low cost. Greater than

Claims (4)

A scroll compressor for converting the rotational movement of the main shaft into a pivoting movement for a fixed scroll having a scroll wrap, and forming a swing scroll coupled with the scroll scroll with the scroll wrap, and a compression chamber for compressing the refrigerant by the relative motion between the scroll wraps. To; A scroll compressor including a screw groove formed in a central portion of a hard plate surface forming a compression chamber of the revolving scroll, a pin fitted into the screw groove, and a capillary tube formed between an outer circumferential surface of the pin and a valley and a valley of the screw groove pitch. Oil discharge reduction structure. The method of claim 1, Partially process the screw grooves that do not penetrate the hard plate surface of the turning scroll, insert a pin contacting the inner diameter of most of the screw grooves, block the screw grooves, and provide an oil drain groove communicating with the passage or gap corresponding to the pitch of the screw grooves. An oil discharge reduction structure of a scroll compressor, characterized in that formed on the hard plate thickness surface of the revolving scroll. The method of claim 1, A groove is formed in the outer wall of the hole penetrating the hard plate surface of the turning scroll, and a pin is inserted into the groove to form a flow path corresponding to the capillary tube on the outer scroll wall to form a flow path toward the back of the low pressure swing scroll from the compression chamber. The oil discharge reduction structure of the scroll compressor characterized by the above-mentioned. The method of claim 3, wherein And forming a hole in the turning scroll, inserting a pin corresponding to the hole, and forming a flow path corresponding to a capillary along an outer wall of the pin.