JP6640518B2 - Displacement compressor - Google Patents

Description

  In the positive displacement compressor, the working fluid pressurized by the compression mechanism is temporarily discharged into the space inside the chamber, and the oil in the working fluid is separated and then discharged outside the machine. There is a high-pressure chamber type in which oil is simply flowed down to return oil.

  In addition, in the positive displacement compressor, the oil is discharged upward from the upper surface of the compression mechanism, and the compression mechanism is arranged at the uppermost part of the chamber space. The working fluid can be efficiently separated from the compressor, and the compressor does not pass through a space where moving members such as a compression drive unit such as a motor are located as much as possible. There is also a top discharge type that discharges outside.

  The present invention relates to a positive displacement compressor on a high pressure chamber, which is advantageous for reducing the oil content (hereinafter referred to as an oil rate) in a working fluid discharged outside the machine, and more particularly realizes further reduction of the oil rate. To a positive displacement compressor.

  An ordinary positive displacement compressor supplies oil to the compression chamber in order to improve the sealing of the compression chamber formed by the compression mechanism. This oil is discharged from the compression mechanism together with the working fluid. If the working fluid discharged inside the machine is directly discharged outside the machine, the amount of oil in the compressor decreases, and the risk of insufficient oil supply to the compression chamber increases. Further, in many cases, the oil in the compressor also plays a role of a lubricant for a sliding portion typified by a bearing, thereby increasing the risk of poor lubrication. Furthermore, in many cases, in equipment using a working fluid discharged outside the machine (for example, a heat exchanger), the oil contained in the working fluid causes performance degradation. For this reason, it is necessary to reduce the oil rate itself. As described above, the oil separating means for separating the oil mist in the working fluid and lowering the oil rate is provided in the path of the working fluid from the inside discharge to the outside discharge.

  In a conventional scroll compressor, which is a positive displacement compressor of a high-pressure chamber top discharge type disclosed in Patent Document 1, a discharge hole serving as an in-machine discharge flow path from the center of the upper surface of a fixed scroll member serving as a compression mechanism upward. A discharge plate that plays the role of changing the upward flow of the main flow of the working fluid into a horizontal flow so that the working fluid containing a large amount of oil discharged from the tank does not directly go to the discharge pipe (discharge pipe), which is an external discharge passage. (Discharge cover) is provided above the fixed scroll member (fixed scroll). Here, since the discharge cover receives a fluid force perpendicular to the thickness direction from the impinging working fluid, the discharge cover needs mechanical strength (flexural rigidity) and is made of a plate material having a thickness that cannot be ignored (Patent) (See Literature Enlarged Figures 2 to 5). In addition, since the fluid force applied to the discharge cover exerts a force to separate the discharge cover from the fixed scroll at the fixed scroll mounting portion of the discharge cover, it is necessary to provide the discharge cover fixed portion with high strength. Therefore, a flat horizontal portion is provided on each of the discharge cover and the fixed scroll, and the two are fixed with screws after improving the adhesion between them. As a result, the discharge cover occupies most of the bottom of the upper space of the compression section, and accordingly, the horizontal portion of the discharge cover also has a large area.

Republished Patent No. 2012-157224

  In the case of the positive displacement compressor of Patent Literature 1, oil mist falls on the discharge cover due to sedimentation caused by gravity in the space above the compression section, and oil accumulates in a horizontal portion provided for screwing the discharge cover. The horizontal part has an inclined surface that smoothly connects to the high part (the convex part that forms the silencing space below), but the connection part to the low part is discontinuous due to the plate thickness over the entire outer edge of the discharge cover as described above. There is only a step portion, and there is no inclined portion that connects smoothly. As a result, the oil that has accumulated in the horizontal portion increases due to the oil that has flowed in from the convex portion that forms the silencing space below, while it is difficult for the oil to flow out of the horizontal portion due to the surface tension of the oil described below. Become. For this reason, the horizontal portion is in a state where the oil is constantly accumulated on one surface, that is, a state where the oil is covered with the oil film.

  Next, the reason why oil does not easily flow out from the horizontal portion of the discharge cover will be described. In order for the oil in the horizontal portion of the discharge cover to flow beyond the step at the outer edge of the discharge cover, the surface area of the oil film must once increase significantly. This can be understood from the fact that the two-dot chain line is much longer than the broken line in FIG. A force along the surface called surface tension acts on the oil at all times, and acts so as to change in a direction that does not increase the surface area of the oil. Then, the greater the change in the tendency for the surface area to increase, the greater the degree of suppression of the change. Therefore, the surface tension of the oil acts so that the oil does not exceed the step on the outer edge of the discharge cover. That is, the oil acts so as to collect in the horizontal portion of the discharge cover. As a result, an oil film is formed on the horizontal portion of the discharge cover. This increase in the oil film thickness continues until the product of the average pressure and the oil film thickness at the oil film end face at the step portion on the outer peripheral edge of the discharge cover exceeds the level of the surface tension. Only when the outflow condition is reached, the end face of the oil film collapses. That is, the oil flows out from the horizontal portion of the discharge cover over the step of the outer edge of the discharge cover. The oil cannot accumulate on the entire horizontal portion until the oil film is formed. And even if the oil flows out from the horizontal portion, before the oil film on the entire horizontal portion is cut and the oil film area is reduced, the above outflow condition is not satisfied due to the decrease in the oil film thickness, and the oil from the discharge cover horizontal portion is not Outflow stops. For this reason, although the oil film thickness increases and decreases, the oil film area spreading over the entire horizontal portion does not decrease. As a result, the entire area of the discharge cover horizontal portion is always covered with the oil film. Therefore, since oil is always present in a wide area of the discharge cover adjacent to the working fluid in the space above the compression section immediately before the outside discharge, the oil is easily entrained in the working fluid flowing immediately before the outside of the machine. Therefore, there is a problem that remisting proceeds and the oil rate increases.

  An object of the present invention is to provide a positive displacement compressor that solves the above problems.

In order to solve such a problem, the present invention provides a compression mechanism unit that compresses a suction gas, which is a working fluid of a suction pressure introduced from the outside, into a discharge gas having a discharge pressure, and the compression mechanism unit. A chamber including a cylindrical chamber cylindrical portion having an axial direction including a vertical direction, a chamber upper lid portion closing an upper end thereof, and a chamber lower lid portion closing a lower end thereof, and the chamber space which is an internal space of the chamber is provided with the discharge gas. Through an in-machine upper discharge passage for discharging the discharge gas from the upper surface of the compression mechanism to the chamber space above the compression mechanism, and the chamber for discharging the discharge gas in the chamber space to the outside. An external discharge flow path, an oil storage section for storing oil in a lower portion of the chamber space, and oil mixing means for mixing oil into the working fluid before the end of the compression stroke from the oil storage section. In that displacement type compressor, so the compression mechanism section disposed in the upper portion of the chamber space, outside discharging the outside discharge passage from the compression mechanism upper compressing section space is a chamber space The compression mechanism upper surface of the in-machine upper discharge flow path is provided so as to connect the space above the compression section to the outside, and changes the flow of the discharge gas discharged into the apparatus upward from the in-machine upper discharge flow path in the horizontal direction. The discharge plate is disposed between an in-machine discharge port which is an opening on the side of the compressor and an external discharge port which is an opening on the space above the compression section of the external discharge flow path, and a horizontal plate on the upper surface of the compression mechanism section. A discharge section is provided which is fixed in a horizontal portion and has a plate-shaped discharge plate. The discharge gas discharged from the discharge port in the machine is compressed outside the discharge plate lower space via the discharge plate lower space. It is those leading to the upper space, the compressor the oil storage portion Provided in the compressed subordinate space is the chamber space side subordinates, the discharge plate inclined portion of the inclined from the discharge plate horizontal portion to steplessly smoothly downwardly provided, discharge plate inclined tip is inclined lowest portion of said discharge Deban inclined portion In the vicinity of the portion, an inclined tip oil return opening, which is one opening of an oil return passage connected to the oil storage unit, is provided.

  According to the present invention, a positive displacement compressor capable of reducing the oil rate with a simple configuration can be realized. As a result, the sealing performance of the compression chamber can be stably improved, so that a highly efficient positive displacement compressor can be realized. Further, since stable lubrication to sliding parts such as bearings can be realized and the risk of poor lubrication can be avoided, a highly reliable positive displacement compressor can be realized. Further, there is an effect that the performance of a device (for example, a heat exchanger or the like) using the working fluid discharged outside the device can be improved.

1 is a longitudinal sectional view of a scroll compressor according to a first embodiment. FIG. 3 is an enlarged vertical cross-sectional view of the vicinity of a compression mechanism of the scroll compressor according to the first embodiment (a section M in FIG. 1 and a cross section JJ in FIG. 3). FIG. 2 is a cross-sectional view of the upper part of the compression mechanism of the scroll compressor of the first embodiment (solid AA cross section). FIG. 4 is an enlarged top view near the inclined portion of the cover of the scroll compressor according to the first embodiment (part N in FIG. 3). FIG. 3 is an enlarged vertical cross-sectional view of the vicinity of a discharge cover of the scroll compressor according to the first embodiment (part K in FIG. 2). FIG. 5 is an enlarged vertical cross-sectional view of the vicinity of an outer edge of a discharge cover of the scroll compressor according to the first embodiment (a portion T in FIGS. FIG. 11 is an enlarged vertical cross-sectional view of the vicinity of the outer edge of the discharge cover of the scroll compressor according to the second embodiment (T portion in FIGS. 5, 9, and 10). FIG. 7 is an enlarged vertical cross-sectional view of the vicinity of the outer edge of a discharge cover of a scroll compressor according to a third embodiment (a portion T in FIG. 5). FIG. 10 is a vertical cross-sectional view of the vicinity of a discharge cover of a scroll compressor according to a fourth embodiment (part K in FIG. 2). FIG. 13 is a vertical sectional view of the vicinity of a discharge cover of a scroll compressor according to a fifth embodiment (part K in FIG. 2). FIG. 10 is an enlarged top view of the vicinity of a cover inclined portion of the scroll compressor according to the sixth embodiment (N portion in FIG. 3). FIG. 14 is an enlarged top view of the vicinity of a cover inclined portion of the scroll compressor according to the seventh embodiment (N portion in FIG. 3). FIG. 4 is a schematic illustration of an enlarged surface area of oil when an oil film flows out over a step.

  Hereinafter, an embodiment in which the present invention is applied to a scroll compressor 1 which is a type of a positive displacement compressor will be described in detail with reference to the drawings as appropriate. In each of the drawings, common portions are denoted by the same reference numerals, and redundant description will be omitted.

  First Embodiment A high-pressure chamber discharge type scroll compressor 1 according to a first embodiment will be described with reference to FIGS. 1 to 6. 1 is a vertical cross-sectional view of a scroll compressor, FIG. 2 is an enlarged vertical cross-sectional view of the vicinity of a compression mechanism (a section M in FIG. 1 and a cross section JJ in FIG. 3), and FIG. It is a front view (solid AA cross section). Here, the arrows in the figure schematically show the flow of the working fluid. Further, a cross mark in the circle indicates the flow of the working fluid from the front to the back of the figure, and a dot mark in the circle indicates the flow of the working fluid from the back to the front in the figure. FIG. 4 is an enlarged top view near the inclined portion of the cover (N in FIG. 3), and FIG. 5 is an enlarged vertical cross section near the discharge cover of the scroll compressor (K in FIG. 2). Here, the arrows in FIGS. 4 and 5 schematically show the flow of oil that has accumulated on the discharge cover due to sedimentation. FIG. 6 is an enlarged vertical cross-sectional view of the vicinity of the outer edge of the discharge cover (T portion in FIG. 5). Note that, in portions other than those described as schematic diagrams, the dimensional ratios of the illustrated elements indicate one embodiment. Therefore, the magnitude relationship between the dimensions in the illustrated shape also shows an embodiment. Here, a specific dimension value is that the outer diameter of the scroll compressor 1 is in a range of 10 mm to 2000 mm.

  First, the overall configuration of the scroll compressor 1 will be described mainly with reference to FIG. The scroll compressor 1 is mainly composed of a fixed scroll 2, an orbiting scroll 3, a frame 4, an Oldham ring 5, and a compression mechanism portion having components thereof, a crankshaft 6 projecting from a lower portion of the compression mechanism portion, and a motor. 7 is sealed in a chamber 8. As a result, a chamber space is formed inside the chamber 8 that surrounds the main components of the arrangement of the uppermost compression mechanism and the motor 7 as a compression starter below the uppermost compression mechanism. Here, the chamber 8 has a cylindrical can shape including a chamber cylindrical portion 8a forming a side surface and a chamber upper lid portion 8b and a chamber lower lid portion 8c closing the upper and lower portions thereof, and the central axis of the chamber axis is vertical. is there. The chamber space is divided by the compression mechanism, and the upper space above the compression unit is referred to as the uppermost chamber 140. The functional name of the chamber space on the lower side of the compression mechanism is referred to as the compression unit lower space. Then, a discharge pipe 55, which is an external discharge passage connecting the chamber space to the outside, is provided in the chamber upper lid portion 8b so as to be connected to the uppermost material 140.

  As shown in FIG. 2, the orbiting scroll 3 has an orbiting wrap 3b erected on the upper surface of an orbiting end plate 3a, and a pin portion 6a, which is an eccentric shaft portion of the crankshaft 6, is inserted into an orbiting bearing 23 on the back surface. The orbiting scroll 3 is configured to orbit by rotating a crankshaft 6 rotatably supported by a main bearing 24 fixedly arranged on the frame 4.

  On the other hand, as shown in FIG. 2, the fixed scroll 2 has a fixed wrap 2b erected on the lower surface side of the fixed end plate 2a, and a fixed base plate 2q is arranged around the fixed wrap 2b. The fixed wrap 2b and the above-described swivel wrap 3b are engaged with each other, and a compression chamber 100 is formed therebetween.

  The fixed scroll 2 is provided with a suction hole 2s (see FIG. 3), into which a suction pipe 50 for introducing a working fluid into the fixed scroll 2 from outside the scroll compressor 1 is press-fitted. Near the center of the upper surface of the fixed scroll 2, a discharge hole 2d through which the compressed working fluid is discharged upward and a plurality of bypass holes 2e are formed. That is, the discharge hole 2d and the plurality of bypass holes 2e form an in-machine upper discharge passage. As described above, the compression mechanism is disposed at the top of the chamber space, and as will be described later, the fixed scroll 2 is disposed at the top of the compression mechanism. Is a position facing the discharge pipe 55.

  By the way, each of the bypass holes 2e is provided with a bypass valve 22 that allows only one-way flow upward from the compression chamber 100. The bypass valve 22 includes a valve plate, a spring, a spring holder, a plate-shaped holder holding member, and a holder holding screw (see FIG. 2). Further, a peripheral groove 2p provided on the lower surface of the fixed base plate 2q is connected to the compression chamber 100, and a back pressure valve flow path 2g having a back pressure valve 26 is formed in the middle thereof. Further, a plurality of outer peripheral grooves 225 are provided on the outer peripheral surface of the fixed base plate 2q.

  A fixed upper wall 2w is provided on the outer periphery of the upper surface of the fixed scroll so as to surround the in-machine upper discharge flow path of the discharge hole 2d and the bypass hole 2e. Three grooves 2w1 are provided. This is not limited to three places. The upper surface of the fixed upper wall 2w is a fixed upper wall horizontal surface 2w5 which is a flat horizontal surface.

  By the way, in this embodiment, a flat discharge cover 200 having a high bending rigidity and a thickness that covers the entire area of the fixed upper wall 2w is fixed to the fixed upper wall horizontal surface 2w5 with a plurality of cover screws 210. A flat cover mounting flat portion 200a is provided on the outer periphery of the discharge cover 200 so as to be in close contact with the fixed upper wall horizontal surface 2w5 to realize strong fixing. Then, a cover inclined portion 200b which is smoothly and continuously inclined to the side in close contact with the fixed upper wall horizontal surface 2w5 is provided continuously with the cover attachment flat portion 200a.

  As described above, since the discharge cover 200 is fixed to the fixed upper wall horizontal surface 2w5 of the fixed scroll 2 by the cover screw 210 as described above, the cover mounting flat portion 200a is arranged horizontally. Further, the cover inclined portion 200b is a portion that smoothly and smoothly inclines downward from the horizontal cover attachment flat portion 200a. These facts and the fact that the fixed scroll 2 is located at the uppermost part of the compression mechanism section as described later means that the discharge cover 200 is arranged between the in-machine discharge port and the out-of-machine discharge port. It is understood that it is responsible for. It can be seen that the cover mounting flat portion 200a is a discharge plate flat portion, and the cover inclined portion 200b is a discharge plate inclined portion.

  As described above, the fixed scroll 2 to which a number of accessories including the discharge cover 200 are mounted has the Oldham ring 5 and the crankshaft 6 mounted on the frame 4 and the outer periphery of the fixed base plate 2q is downwardly moved to the crankshaft. 6 is fixed to the stretched frame 4 with frame screws 53. Thus, a back pressure chamber 110 is formed on the back surface of the orbiting scroll 3 (between the orbiting scroll 3 and the frame 4). The Oldham ring 5 is disposed between the frame 4 and the orbiting scroll 3 in order to prevent the orbiting scroll 3 from rotating. By such an assembly, a compression mechanism is formed. As described above, the uppermost portion of the compression mechanism is a fixed scroll.

  A vertically extending fuel supply hole 6b is formed in the crankshaft 6, and a fuel supply pipe 6x is press-fitted into a lower end thereof.

  The auxiliary bearing 25 includes a ball 25a and a ball holder 25b fixed to the lower frame 35 fixed to the chamber cylindrical portion 8a by welding or the like. Here, the lower frame 35 is provided with a lower frame oil hole 35a for dropping oil flowing down from the compression mechanism side to a lower portion (specifically, an oil storage section 105 described later).

  The motor 7 includes a rotor 7a fixed to the crankshaft 6, a stator 7b shrink-fitted or press-fitted or welded to the chamber cylindrical portion 8a, a motor winding 7c, and an upper part for ensuring insulation between the motor winding 7c and the stator 7b. It is composed of an insulator 7d1, a lower insulator 7d2, and a motor wire 7e. Then, the motor wire 7e is connected to a hermetic terminal 70 which is a motor terminal fixedly arranged in the chamber 8, and power is supplied to the motor 7 from the outside. Further, a balance 60 and a counter balance 62 for obtaining a rotational balance are fixedly arranged on the rotor 7a. Further, a plurality of cut portions 7b1 are provided on the outer peripheral surface of the stator 7a, and serve as a passage through which oil flows.

  As shown in FIG. 2 and FIG. 3, the above-mentioned compression mechanism portion is fixedly arranged by tack welding 57 to the chamber cylindrical portion 8a while holding a narrow outer circumferential gap 220 through which oil can flow down over the entire circumference. A suction pipe 50 press-fitted into the fixed scroll 2 and a discharge pipe 55 serving as an external discharge passage, and a hermetic terminal 70 for supplying electric power to the motor 7 from outside are welded to the chamber upper lid portion 8b. I have. The motor wire 7e reaches the space above the compression section through a motor wire passage outer circumferential groove 2m provided on the outer circumference of the fixed scroll 2. Then, after that, it is arranged so as to be in contact with the cover inclined portion 200b of the discharge cover 200 by the binder 250, and finally connected to the hermetic terminal 70 of the chamber upper lid portion 8b. Here, the binder 250 is fixed to the upper surface 2w5 of the fixed upper wall, and is provided for defining the installation position of the motor wire 7e. This is to avoid the danger that the motor wire 7e moves due to the flow of the working fluid and the like, comes into contact with each part, peels off the coating, and short-circuits. In addition, since the motor wire 7e is installed so as to be in contact with the cover inclined portion 200b, a reliable contact point with the compression mechanism portion is the tip portion of the cover inclined portion. Then, the bend of the motor wire 7e at the contact point becomes a gentle obtuse angle, and there is an effect that the danger of peeling of the coating and disconnection is reduced. The hermetic terminal 70 welded to the chamber upper lid portion 8b may be welded to the chamber cylindrical portion 8a facing the uppermost chamber 140. Oil is sealed inside the chamber 8 at an appropriate stage of assembly. Thereby, the oil storage section 105 is formed at the bottom of the chamber space, that is, at the bottom of the space below the compression section.

  Next, the flow of the working fluid of the scroll compressor 1 will be described. The orbiting scroll 3 is orbited by rotating the crankshaft 6 by the motor 7 to form a compression chamber 100 between the orbiting scroll 3 and the fixed scroll 2. At this time, the working fluid flows from the suction pipe 50 into the compression chamber 100 via the suction port 2s (see FIG. 3). As will be described later, among the compression chambers 100, a compression chamber oil supply passage is provided that connects the compression chamber 100 before the end of the compression stroke or the suction chamber before closing, which is before the formation of the compression chamber, and the oil storage section 105 under the discharge pressure. Thus, oil can be mixed into the working fluid in the compression chamber 100 before the end of the compression stroke due to a pressure difference. That is, the compression chamber oil supply passage serves as oil mixing means. This oil ensures the sealing performance of the compression chamber 100 or the suction chamber. Thereafter, the working fluid is compressed and pressurized as the volume of the compression chamber 100 is reduced, with the oil supplied to the suction chamber and the compression chamber 100. The working fluid is discharged upward from the discharge holes 2d and the bypass holes 2e opened on the upper surface of the fixed end plate 2a (see FIG. 2) which is the upper surface of the compression mechanism. That is, the discharge holes 2d and the bypass holes 2e are upper internal discharge passages.

  After that, most of the working fluid discharged inside the machine is turned into a horizontal flow by the discharge cover 200 and blows out from the fixed upper wall turning groove 2w1, which is the opening of the fixed upper wall 2w, to around the compression mechanism. . Due to the sudden change of the flow direction of the working fluid by the discharge cover 200, oil in the working fluid adheres to the lower surface of the discharge cover 200 due to inertia, and oil separation occurs. Further, the oil in the working fluid that has blown out from the fixed upper wall 2w adheres to the inner peripheral surface of the chamber cylindrical portion 8a again by inertia, and the oil of the working fluid is separated again. On the other hand, since the fixed upper wall swirl groove 2w1 (shown by a broken line in FIG. 3) has a direction deviated from the radial direction, the working fluid blown out around the compression mechanism causes a swirl flow (shown by an arrow in FIG. 3). . For this reason, high-density oil adheres to the inner peripheral surface of the chamber cylindrical portion 8a by centrifugal action, and further oil separation occurs. This swirling flow is suppressed from flowing into the uppermost chamber 140 by the upper lid lower end surface 8b1, which is the lower end surface of the chamber upper lid portion 8b.

  Thereafter, the working fluid flows into the uppermost chamber 140 from the center of the swirling flow. Since the volume of this space is large, the average flow velocity of the working fluid decreases, the carrying capacity of the working fluid for transporting high-density oil decreases, and the oil sinks. In addition, since there are no moving elements such as valves and motors, the turbulence of the flow is reduced, and the probability that the flow velocity of the working fluid locally increases is reduced. Therefore, almost no flow hinders oil sedimentation. Further, since the discharge pipe 55, which is an external discharge passage, is provided at the uppermost portion, the probability that oil is transported to the uppermost portion by the working fluid can be further reduced. As a result, the mist-like oil slightly contained in the working fluid flowing into the uppermost chamber 140 also settles in the uppermost chamber 140 by gravity. As described above, in the uppermost chamber 140, the oil separation proceeds due to the sedimentation action, and the oil rate is further reduced. By the way, the oil settled at this time is deposited on the upper surface of the discharge cover 200 installed on the upper part of the compression mechanism occupying most of the bottom of the uppermost chamber 140.

  Finally, the working fluid is discharged outside the scroll compressor 1 from the discharge pipe 55, which is a discharge passage outside the device, to the outside of the scroll compressor 1. As described above, the scroll compressor, which is the positive displacement compressor of the present embodiment, has the internal discharge above the compression mechanism, and does not allow the main flow of the working fluid to flow to the space below the compression unit, as described above. It is an upper discharge type because oil is separated and discharged only in the upper space. In the upper discharge type, since the main flow of the working fluid does not flow into the space under the compression section, the flow of the working fluid in the entire space under the compression section is extremely weak. Therefore, even if the oil flow path in the space under the compression section is incomplete, remisting of the oil does not occur, and the oil rate can be easily reduced. Further, since the motor 7 is not heated, there is also an effect that the compressor route is improved by reducing the motor loss. Further, as can be seen from the above, since the entire chamber space has a discharge pressure, it is also a high-pressure chamber type.

  Next, a general oil flow will be described. The flow of the oil separated on the way from the above-described internal discharge passage to the external discharge passage will also be described.

  The oil in the oil storage unit 105 is supplied from the oil storage unit 105 by the pressure difference between the discharge pressure (the pressure inside the chamber 8) and the back pressure (the pressure inside the back pressure chamber 110). After lubricating the slewing bearing 23 and the main bearing 24 through the hole 6b, it flows into the back pressure chamber 110. Here, the pressure in the orbiting bearing chamber 115 above the pin portion 6a becomes the discharge pressure, and plays a role of urging the orbiting scroll 3 to the fixed scroll 2. The auxiliary bearing 25 is supplied with oil from the oil supply hole 6b by centrifugal force. Here, since the pressure of the oil before flowing into the back pressure chamber 110 is the discharge pressure, the back pressure increases due to the flow of the oil. Also, since the working fluid is always dissolved in the oil (in many cases, the mass concentration is 10% or more), the working fluid is rapidly gasified (bubbled) from the oil by the pressure reduction caused by flowing into the back pressure chamber 110. ). Since the working fluid increases in volume due to gasification, the oil in the back pressure chamber 110 is formed as a mist state in which fine oil droplets float in the gasified working fluid or a collection of bubbles in which the liquid oil has many bubbles. State. The oil dispersed throughout the back pressure chamber 110 in this manner lubricates the Oldham ring 5.

  After that, most of the oil flows into the compression chamber 100 through the back pressure valve flow path 2g provided with the back pressure valve 26 in the middle. Here, the oil in the compression chamber 100 exhibits the effect of improving the sealing performance of the compression chamber 100, suppresses the leakage of the working fluid in the compression chamber 100, and improves the compressor efficiency. On the other hand, part of the oil that has flowed into the back pressure chamber 110 also flows into the suction chamber through a small gap between the fixed base plate 2q and the revolving end plate 3a. There is also a case where another means for positively supplying oil to the suction chamber is provided (for example, Japanese Patent No. 5548586). By controlling the amount of oil flowing into the suction chamber to an appropriate amount, volume efficiency is improved due to the effect of improving the sealing performance of the suction chamber, and the effect of improving compressor efficiency is exhibited. As described above, the oil flows into the back pressure chamber 110 once from the oil storage section 105 through the slewing bearing 23 and the main bearing 24, and further flows from the oil supply path to the back pressure valve flow path 2g and the suction chamber to the suction hole 2s and the suction hole 2s. It flows into the compression chamber 100 via the chamber. The oil plays a role in improving the sealing performance of the compression chamber 100 and the suction chamber. In other words, an oil path extending from the oil storage section 105 to the compression chamber 100 or the suction chamber is a compression chamber oil supply path, that is, an oil mixing means. The back pressure valve 26 provided in the back pressure valve passage 2g has a structure in which a valve plate is pressed against a valve seat by a compression spring. As a result, the back pressure is controlled to a pressure that is higher than the pressure in the compression chamber 100 to which the back pressure valve flow path 2g communicates by a substantially constant value. The above-mentioned substantially constant value (the average pressure of the compression chamber 100 to which the back pressure valve passage 2g communicates) can be set by adjusting the compression amount of the compression spring. The orbiting scroll 3 is urged toward the fixed scroll 2 by the back pressure and the discharge pressure of the orbiting bearing chamber 115. As a result, the gap between the end face of the lap and the end plate is narrowed to suppress the internal leakage of the compression chamber 100 and improve the efficiency of the compressor.

  Thereafter, as described in the flow of the working fluid, the oil mixed with the working fluid is ejected upward from the in-machine upper discharge passage of the discharge hole 2d or the bypass hole 2e together with the flow of the work fluid, and collides with the discharge cover 200. . As a result, while the flow of the working fluid is bent in all directions in the horizontal direction (see FIG. 2), most of the oil collides with the discharge cover 200 because the oil has a greater inertia than the working fluid. As a result, the oil adheres to the lower surface of the discharge cover 200 and is separated from the working fluid. Here, if the viscosity of the oil is high, the ratio of the oil adhering increases, and this oil separation operation can be performed efficiently. It has been experimentally confirmed that when the viscosity of the oil at the time of discharge is 0.01 Pa · s or more, the oil separation effect due to collision becomes extremely high regardless of the mass flow rate of the working fluid. For example, the case of a compressor for a water heater using carbon dioxide as a refrigerant corresponds to the condition. The working fluid is finally discharged from the discharge pipe 55 provided at the upper part of the compressor to the outside of the compressor, and therefore flows near the lower surface of the discharge cover 200. The oil adhering to the discharge cover 200 is pushed by the flow of the working fluid and reaches the inner peripheral surface of the fixed upper wall 2w. Thereafter, the oil flows down the inner peripheral surface of the fixed upper wall 2w to the upper surface of the fixed scroll 2 by gravity. This allows the oil to flow down from the lower surface of the discharge cover 200 close to the main flow of the working fluid to the upper surface of the fixed scroll 2 which is separated from the main flow of the working fluid to some extent, and has an effect of reducing the oil rate. On the other hand, there is oil that is pushed by the flow of the working fluid and reaches the fixed upper wall turning groove 2w1, but because the fixed upper wall 2w is thick, the fixed upper wall turning groove 2w1 passes through the fixed upper wall turning groove 2w1. There is a flow path to the side surface and to the bottom surface of the fixed upper wall turning groove 2w1. As a result, remisting of the oil can be suppressed, and there is also an effect peculiar to the embodiment of reducing the oil rate. The oil that has reached the upper surface of the fixed scroll 2 as described above flows out to the outer periphery of the fixed upper wall 2w along the bottom surface of the fixed upper wall turning groove 2w1. Thereby, although there is some distance from the main flow of the working fluid, it is possible to suppress the accumulation of oil on the upper surface (the upper surface of the compression mechanism) of the fixed scroll 2 in which the danger of remisting remains to some extent. Thereby, an effect that the oil rate is reduced is produced. As described above, most of the oil is separated by the collision of the working fluid with the discharge cover 200, flows out to the outer periphery of the fixed upper wall 2w, and finally flows into the outer peripheral gap 220 and the outer peripheral groove 225. From there, it returns to the lowermost oil storage section 105 through the motor 7 while traveling along the inner surface of the chamber cylindrical section 8a. Here, the motor 7 passes through a cut portion 7b1 provided on the outer peripheral surface of the stator 7b and a vertical hole in the stator 7b through which the motor winding 7c passes. That is, the path from the outer circumferential gap 220 or the outer circumferential groove 225 to the oil storage section 105 is a oil return path, and the upper opening of the outer circumferential gap 220 or the outer circumferential groove 225 is the oil return opening.

  As described above, the oil that cannot be separated by the first-stage oil separation performs the second-stage oil separation by the impact on the inner surface of the chamber cylindrical portion 8a and the subsequent centrifugal separation by the swirling flow. 8a adheres to the inner surface. Thereby, there is an effect that the oil rate can be further reduced. As shown in FIG. 3, the oil adhering to the collision is guided to the oil return path in a short time because the outer peripheral groove 225 having a large opening area is provided immediately below the collision point. Separated oil due to the swirling flow is guided to the oil return path from the outer peripheral gap 220 distributed immediately below. As described above, the separated oil adhering to the inner surface of the chamber cylindrical portion 8a travels along the inner surface of the chamber cylindrical portion 8a because the outer circumferential groove 225 and the outer circumferential gap 220, which are the inlets of the oil return passage, are opened right below. The oil flowing down does not stay, and remisting of the oil can be avoided. Therefore, there is an effect that the oil rate can be further reduced.

  The working fluid that has been subjected to the first and second stages of oil separation finally enters the uppermost chamber 140 through an annular opening between the outer peripheral surface of the fixed upper wall 2w and the lower end surface 8b1 of the upper lid, Oil separation from the working fluid is further performed by the above-described settling action. As a result, the separated oil accumulates on the upper surface of the discharge cover 200 as described above. This oil flow will be described mainly with reference to FIGS. Here, in these cross-sectional views, the cross-section and the flow of oil separated from the working fluid at the back side of the cross-section are indicated by thin-line arrows. In addition, a flow that is important before the cross section is indicated by a two-dot chain line.

  As described above, the discharge cover 200 of the present embodiment is a flat portion including not only the cover mounting flat portion 200a on the outer side but also the center thereof. One of the outer sides of the wide flat portion is smoothly inclined downward, forming a cover inclined portion 200b. As described above, the oil mist is deposited on the flat portion from the working fluid in the uppermost upper chamber 140. Then, an oil film is formed on each of the flat portions, and they are connected to grow into a wide oil film. When the oil film is applied to the inclined cover portion 200b, the connection with the flat portion is continuously smooth, so that the oil film starts flowing down almost without being affected by surface tension. Once the oil film starts flowing, the oil film does not break due to the surface tension, and the weight of the oil film portion flowing down the inclined cover portion 200b pulls the oil film on the flat portion connected to the oil film to the inclined cover portion 200b. In this way, most of the oil film on the upper surface of the discharge cover 200 flows down the cover inclined portion 200b, and the area without the oil film spreads on the upper surface of the discharge cover 200. As described above, since the residence time of the oil remaining on the upper surface of the discharge cover 200 closest to the discharge pipe 55, which is the external discharge passage, can be shortened, it is difficult to re-mist, and the oil rate is reduced. Further, the oil film flowing down the cover inclined portion 200b flows down to the tip of the cover inclined portion 200b as it is. In the present embodiment, as described above, since there is no flat portion at the tip end, there is no place where oil stably accumulates, and the surface tension of the oil acts due to the plate thickness (step) of the tip end of the cover inclined portion 200b. Damming occurs. However, since the gravitational component along the inclined surface acts on the oil mass (oil film) that accumulates here, the oil film easily climbs over the step and flows away from the cover inclined portion 200b. Further, the oil flowing down gathers from a wide flat portion including the inclined cover attachment flat portion 200a, so that the oil film thickness increases in a short time and flows down from the cover inclined portion 200b in a shorter time. Since the upper end opening of the outer circumference groove 2m of the motor wire currency is located near the fall, the flow of the working fluid is extremely weak in a short time and the working fluid flows down to the space under the compression section where the danger of remisting the oil is low. Thus, the upper end opening of the motor wire currency outer circumferential groove 2m is also an inlet of the oil return path, and returns to the oil storage section 105 through the oil return path connected to the motor wire currency outer circumferential groove 2m. Thus, the upper end opening of the motor wire currency outer circumferential groove 2m is an inclined front end hot water return opening.

  In this embodiment, the motor wire 7e is further in contact with the end of the cover inclined portion 200b. Since the coating of the motor wire 7e has lipophilicity, the oil accumulated at the end of the inclined cover portion 200b comes into contact with the surface of the motor wire 7e and at the same time moves onto the surface of the motor wire 7e. Although the contact position between the motor wire 7e and the cover inclined portion 200b changes depending on the installation position and posture of the binder 250 holding the motor wire 7e, the oil is temporarily blocked by the binder 250 as in the present embodiment. The tip is the contact point. The oil at the tip of the cover inclined portion 200b that has come off from the position where the motor wire 7e comes into contact is also drawn and moves to the motor wire 7e. As a result, the oil accumulated at the tip of the cover inclined portion 200b moves to the motor wire 7e in a shorter time. The motor wire 7e passes through the motor wire outer circumferential groove 2m while being in contact therewith and is connected to the motor winding 7c in the space below the compression section. It flows down the motor wire currency outer circumferential groove 2m and the motor winding 7c along the motor wire 7e. As a result, the motor wire 7e serves as a contact member, and the oil accumulated at the end of the cover inclined portion 200b moves to the space under the compression portion where the flow of the working fluid is extremely weak within a shorter time, so that the oil rate is further increased. To achieve a reduction. Thereafter, it merges with the oil flow in the oil return path described above and returns to the oil storage unit 105.

  Further, in the present embodiment, in addition to the outflow path having a small flow path resistance formed by the fixed upper wall turning groove 2w1 as the outflow path below the discharge plate, which is the outflow path from the space below the discharge cover 200, the cover inclined portion 200b is formed. There is provided a fixed upper wall inclined lower groove 2w2 which forms a discharge plate inclined tip flow path passing through the lower end surface. As shown in FIG. 2, this is a flow path for forcing a flow downward against the general upward flow of the working fluid toward the discharge pipe 55 which is an external discharge flow path. Furthermore, since the cross-sectional area (average value) of the flow path is small and the cross-sectional shape is elongated and rectangular, the perimeter of the cross-section is long, the resistance force that impedes the flow from the flow path wall to the working fluid flowing therethrough Becomes larger. Accordingly, the flow path resistance becomes larger than that of the other discharge plate lower flow path. Accordingly, the flow velocity of the working fluid flowing through the discharge plate lower outflow channel (referred to as the cover inclined lower channel 230) formed by the fixed upper wall inclined lower groove 2w2 is equal to the discharge plate lower flow formed by the fixed upper wall swirl groove 2w1. It becomes smaller than the flow velocity of the working fluid flowing through the passage. Accordingly, the flow velocity of the working fluid flowing through the cover inclined lower flow path 230 is smaller than that of the other discharge plate lower flow paths. As a result, the oil that accumulates at the tip of the cover inclined portion 200b, which is the discharge plate inclined tip, is easily separated from the cover inclined portion 200b by the working fluid flowing through the cover inclined lower channel 230. And since the flow velocity in that location is low, the danger of becoming oil mist can also be avoided. In this embodiment, since the motor wire 7e, which is a contact member, is also in contact, most of the oil separated from the cover inclined portion 200b by the working fluid flowing through the cover inclined lower flow path 230 reduces the motor wire 7e in a shorter time. And flows into the oil return. Therefore, there is an effect that the oil rate can be further reduced. It is conceivable that the cover inclined lower flow path 230 is not provided. In this case, the swirl flow flowing out of the other discharge plate lower flow path becomes strong, and there is an effect that oil separation by centrifugation is effectively performed. Further, the discharge plate lower outflow path may be set in a radial direction which does not cause a swirling flow.

  Further, the outlets of the discharge plate lower outflow passage of the present embodiment are all provided on the outer peripheral side surface of the compression upper wall 2w, and are not installed on the discharge plate flat portion including the cover mounting flat portion 200a in which the oil accumulates. Therefore, there is a small risk that oil is caught in the working fluid when the oil is blown out from the outlet of the discharge plate lower outlet passage, and the oil rate is further reduced.

  In the present embodiment, as shown in FIGS. 1 and 2, the motor wire 7 e crosses near the center of the uppermost chamber 140 and is connected to the hermetic terminal 70. Since the surface of the motor wire 7e is covered with a lipophilic coating, when the oil mist floating in the uppermost chamber 140 comes into contact with the coating of the motor wire 7e, it sticks to the surface of the motor wire 7e and travels along the motor wire 7e as it is. The oil is quickly guided to the oil return path through the passing outer circumferential groove 2m. As a result, the working fluid flows into the space under the compression section in which the main flow does not flow in a short time, and the oil rate is further reduced.

  Next, a scroll compressor according to a second embodiment will be described with reference to FIG. FIG. 7 is an enlarged vertical cross-sectional view of the outer periphery of the discharge cover, which is a portion T in FIG. 5, of the scroll compressor 1, and particularly on the discharge plate lower outflow channel formed by the fixed upper wall turning groove 2w1 through which the main flow of the working fluid passes. Except for having a cover burr end portion 200x in which an upward burr is intentionally left on the outer edge of the portion, the embodiment is the same as the first embodiment, and a description of similar portions is omitted.

  By the cover burr end portion 200x, it is possible to further suppress the oil accumulated in the cover mounting flat portion 200a on the outer periphery of the discharge cover 200 from being caught in the main flow of the working fluid flowing through the discharge plate lower outflow path formed by the fixed upper wall turning groove 2w1. . As a result, there is an effect that the oil rate can be reduced.

  This effect can be further ensured by setting the cover warped end portion 200y as shown by the two-dot chain line. By the way, the upward projections of these outer edges may be formed not only in the upper portion of the discharge plate lower outflow channel formed by the fixed upper wall turning groove 2w1, but also in the entire flat portion. Thereby, there is an effect that the processing is facilitated and the processing cost can be reduced.

  Next, a scroll compressor according to a third embodiment will be described with reference to FIG. FIG. 8 is an enlarged vertical cross-sectional view of the vicinity of the outer edge of the discharge cover, which is a portion T in FIG. Except for having a short cover downward inclined end 200z in which the outer edge other than the outer edge is inclined downward, the first or second (provided that the upward projection of the outer edge is provided by the fixed upper wall turning groove 2w1) (Only the upper part of the lower plate outflow path) is the same as the embodiment, and the description of the same parts will be omitted.

  By the cover downward inclined end portion 200z, oil collected in the cover mounting flat portion 200a on the outer periphery of the discharge cover 200 is not caught in the main flow of the working fluid flowing through the discharge plate lower outflow path formed by the fixed upper wall turning groove 2w1. , Can flow down in a wide range. As a result, the oil residence time on the cover attachment flat portion 200a can be shortened, and thus there is an effect that the oil rate can be reduced.

  Next, a scroll compressor according to a fourth embodiment will be described with reference to FIG. FIG. 9 is a vertical cross-sectional view of the vicinity of a discharge cover, which is a portion K in FIG. 2, of the scroll compressor 1. The scroll compressor 1 is similar to the first to third embodiments except that a gently raised cover projection 200c is provided at the center. Since it is the same, description of the same part is omitted.

  Since the upper portion of the cover convex portion 200c has a gentle slope, the oil that accumulates there flows down in a very short time and is collected and collected in the cover mounting flat portion 200a on the outer periphery. Therefore, the area where the oil exists is narrowed, and the danger of remist formation is reduced. Furthermore, since the oil film thickness of the cover attachment flat portion 200a is increased in a short time due to aggregation, the time interval flowing down from the cover inclined portion 200b is shortened, and the time for forming the oil film over the entire flat portion is shortened. As described above, there is an effect that the oil rate can be further reduced.

  Next, a scroll compressor according to a fifth embodiment will be described with reference to FIG. FIG. 10 is a vertical cross-sectional view of the vicinity of the discharge cover, which is a portion K in FIG. 2 of the scroll compressor 1, in which a smoothly concaved cover concave portion 200d is provided on the entire central surface, and the lowest portion of the cover concave portion 200d is formed as a cover inclined portion. Except for the top of 200b, the third embodiment is the same as the first to third embodiments, and a description of similar parts will be omitted.

  Since the entire area of the cover recess 200d has a gentle slope, the oil that accumulates there flows down to the lowest portion of the cover recess 200d in a very short time. For this reason, the time during which oil accumulates in the cover attachment flat portion 200a on the outer side and an oil film is formed is reduced. Furthermore, since the lowest part of the cover concave part 200d is the uppermost part of the cover inclined part 200b, the oil collected at the lowest part of the cover concave part 200d immediately flows down from the cover inclined part 200b without collecting. As a result, the oil that accumulates over the entire area of the discharge cover 200 flows down to the tip of the cover inclined portion 200b in a very short time, and the time that the oil stays on the upper surface of the discharge cover 200 is extremely short. As described above, there is an effect that the oil rate can be further reduced.

  Next, a scroll compressor according to a sixth embodiment will be described with reference to FIG. FIG. 11 is an enlarged top view of the vicinity of the cover inclined portion, which is the N portion of FIG. 3, of the scroll compressor 1, and shows a cover inclined portion connecting the cover inclined portion 200b and the cover mounting flat portion 200a on both sides thereof with an inclined surface. Except for providing the connection part 200d1, the configuration is the same as that of the first to fifth embodiments, and the description of the same parts is omitted.

  There is a path through which oil that accumulates on the cover attachment flat portion 200a on both sides of the cover inclined portion 200b flows directly down to the cover inclined portion 200b through the cover inclined connection portion 200d1, so that the oil remaining on the upper surface of the discharge cover 200 is even shorter. With time, it flows down to the tip of the cover inclined portion 200b, and the time of staying on the upper surface of the discharge cover 200 is further reduced. As described above, there is an effect that the oil rate can be further reduced.

  Next, a scroll compressor according to a seventh embodiment will be described with reference to FIG. FIG. 12 is an enlarged top view of the vicinity of the cover inclined portion, which is the N portion of FIG. 3, of the scroll compressor 1, and illustrates a cover binder portion 200e in which a binder that defines the installation position of the motor wire 7e is integrated with the discharge cover. Except for the above, the configuration is the same as that of the fifth embodiment, and the description of the same parts is omitted. Here, in the present embodiment, the type of the cover inclined portion 200b in which the cover inclined connection portion 200d1 is provided is provided. However, the provision of the cover inclined connection portion 200d1 is not essential, and as in the first to fifth embodiments, The present invention is also applicable to a type in which the oblique connection portion 200d1 is not provided. Since the binder is integrated, the work of attaching the binder is not required, and there is an effect that the assembly cost is reduced.

  Until now, it has been assumed that there is no horizontal portion at the tip of the discharge plate. However, even if the tip of the discharge plate is formed with a horizontal portion, the horizontal portion of the tip does not discharge outside the machine. Since it is located one step lower than the cover mounting flat portion 200b in which the working fluid on the verge flows, the danger of oil entrapment is avoided and the problem of an increase in the oil rate does not occur.

  The positive displacement compressor described so far has been a scroll compressor, but the present invention is not limited to this, but can be applied to any positive displacement high pressure chamber type positive displacement compressor. For example, the present invention is also applicable to a rolling piston type compressor, a screw compressor, and a vane compressor.

  In addition, the viscous fluid, which has been described as oil, may be another fluid depending on the case. For example, in the case of an air compressor that minimizes the mixing of oil in the discharge gas, water is used instead of oil.In these cases, the portion described as oil is replaced with water. I just need. For example, it is applicable to a water lubricated screw compressor and the like.

DESCRIPTION OF SYMBOLS 1 Scroll compressor 2 Fixed scroll 2a Fixed end plate 2b Fixed wrap 2d Discharge hole 2e Bypass hole 2g Back pressure valve channel 2m Motor wire passage outer peripheral groove 2p Peripheral groove 2q Fixed base plate portion 2s Suction hole 2w Fixed upper wall 2w1 Fixed upper wall turning Groove 2w2 Fixed upper wall inclined lower groove 2w5 Fixed upper wall upper surface 3 Orbiting scroll 3a Orbiting head plate 3b Orbiting wrap 4 Frame 5 Oldham ring 6 Crankshaft 6a Pin portion 6b Oil supply hole 6x Oil supply pipe 7 Motor 7a Rotor 7b Stator 7b1 Cut portion 7c Motor Winding 7d1 Upper insulator 7d2 Lower insulator 7e Motor wire 8 Chamber 8a Chamber cylinder 8b Chamber upper lid 8b1 Upper lid lower end face 8c Chamber lower lid 22 Bypass valve 23 Swivel bearing 24 Main bearing 25 Secondary bearing 25a Ball 25b Ball holder 26 Back pressure valve 5 Lower frame 35a Lower frame oil hole 50 Suction pipe 53 Frame screw 55 Discharge pipe 57 Tack welding 60 Balance 62 Counter balance 70 Hermetic terminal 100 Compression chamber 100 'Communication compression chamber 105 Oil storage unit 110 Back pressure chamber 115 Swivel bearing chamber 140 Uppermost chamber 200 Discharge cover 200a Flat cover mounting section 200b Cover inclined section 200c Cover convex section 200d Cover concave section 200d1 Cover inclined connecting section 200e Cover binder section 200x Cover burr end section 200y Cover curving end section 200z Cover falling inclined end section 210 Cover screw 220 Outer peripheral gap 225 Outer peripheral groove 230 Cover inclined lower channel 250 Binder 250a Binder screw

Claims (6)

A compression mechanism for compressing a suction gas, which is a working fluid of a suction pressure introduced from the outside, to a discharge gas as a discharge pressure,
A chamber comprising a cylindrical chamber cylindrical portion having an axial direction in the vertical direction including the compression mechanism portion and a chamber upper lid portion closing the upper end and a chamber lower lid portion closing the lower end,
An in-machine upper discharge passage for discharging the discharge gas from the upper surface of the compression mechanism to the chamber space above the compression mechanism to fill a chamber space that is an internal space of the chamber with the discharge gas;
An external discharge passage that penetrates the chamber for discharging the discharge gas in the chamber space to the outside,
An oil storage unit for storing oil at a lower part of the chamber space,
Oil mixing means for mixing oil from the oil storage section into the working fluid before the end of the compression stroke,
In the displacement type compressor consisting of
Arranging the compression mechanism above the chamber space;
The external discharge flow path is provided so as to connect the external space of the compression unit and the outside so that the external discharge passage is externally discharged from the upper space of the compression unit, which is a chamber space on the upper side of the compression mechanism unit,
The in-machine discharge port, which is an opening on the upper side of the compression mechanism portion of the in-machine upper discharge channel, and the outside of the machine in order to change the flow of the discharge gas discharged in the machine upward from the in-machine upper discharge passage in the horizontal direction. A plate-shaped discharge plate which is disposed between an external discharge port which is an opening of the discharge passage above the compression section above the compression section, and which is fixed in close contact with a horizontal portion of an upper surface of the compression mechanism section by a discharge plate horizontal portion. Provided,
The discharge gas discharged from the in-machine discharge port is to reach a space above the compression unit that is outside the space below the discharge plate via the space below the discharge plate,
The oil storage section is provided in a compression section lower space that is the chamber space below the compression mechanism section,
Providing a discharge plate inclined portion that is smoothly inclined downward without a step from the discharge plate horizontal portion,
In the vicinity of the discharge plate inclined tip which is the lowest inclined portion of the discharge plate inclined portion, providing an inclined tip oil return opening which is one opening of an oil return path connected to the oil storage section.
Characteristic displacement compressor.   The displacement type compressor according to claim 1, wherein an outer peripheral groove connecting an upper surface and a lower surface is provided on an outer peripheral surface of the compression mechanism portion so as to provide the inclined tip oil return opening portion at an outer edge portion of the compression mechanism portion, A positive displacement compressor characterized in that an inclined end of a discharge plate is provided at an outer edge of the compression mechanism.   3. The positive displacement compressor according to claim 2, further comprising: a linear or planar contact member that is in contact with the inclined portion of the discharge plate and is inserted while being in contact with the outer circumferential groove, and the surface of the contact member is a working fluid. A positive displacement compressor characterized by having lipophilicity in an atmosphere of (1).   4. The displacement type compressor according to claim 3, wherein a rotation drive source of the compression mechanism is an electric motor, the motor is disposed in the space below the compression unit, and a motor wire for supplying power to the motor is provided in the outer peripheral groove. A compressor terminal connected to a motor terminal provided in a chamber surrounding the upper space of the compression section, and the contact member being the motor wire.   5. The positive displacement compressor according to claim 2, wherein the working fluid is a flow path of the working fluid from the in-machine discharge port to the outside of the space below the discharge plate via the space below the discharge plate. 6. One of the discharge plate lower outflow passages is a discharge plate inclined front end flow passage that passes through the lower surface of the discharge plate inclined front end portion and has a larger flow resistance than the other discharge plate lower outflow passages. Displacement compressor. The displacement type compressor according to claim 5 , wherein an outlet of the discharge plate lower outflow passage is provided at a position other than the discharge plate horizontal portion.

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