JP2016020664A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll compressor for improving the thrust slidability and sealability of a compression mechanism.SOLUTION: A scroll compressor includes a casing, a compression mechanism, and an ejector mechanism 91. The casing has an oil storage part on the bottom for storing lubricating oil. The compression mechanism has a fixed scroll and a movable scroll. The ejector mechanism 91 is provided in a high pressure space S1. The high pressure space S1 is a space into which the refrigerant compressed by the compression mechanism is supplied. The ejector mechanism 91 utilizes the flow of the refrigerant or the lubricating oil to produce a negative pressure region 93 having a lower pressure than the high pressure space S1. The fixed scroll has an oil groove 24e where the lubricating oil flows. The oil groove 24e is formed in the thrust sliding surface of the fixed scroll having sliding motion with the movable scroll, extending in the peripheral direction thereof. A first end of the oil groove 24e is communicated with the negative pressure region 93.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a scroll compressor.

  Conventionally, a scroll compressor including a compression mechanism having a fixed scroll and a movable scroll is used. In the scroll compressor, each of the fixed scroll and the movable scroll has a wrap that is a spiral projection that meshes with each other. The fixed scroll is fixed to the housing in the casing, and the movable scroll is connected to the crankshaft and rotates eccentrically. As a result, the volume of the compression chamber, which is the space between the wraps of both scrolls, changes, and the refrigerant in the compression chamber is compressed. Further, in the scroll compressor, a back pressure space may be formed on the back side of the movable scroll in order to press the movable scroll against the fixed scroll with an appropriate force. In such a scroll compressor, the movable scroll slides while being pressed against the fixed scroll by the action of back pressure.

  By the way, the scroll compressor uses an oil supply mechanism that supplies lubricating oil to a thrust sliding surface on which the fixed scroll and the movable scroll slide. For example, in a scroll compressor disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2001-214872), an annular oil groove is formed in a fixed scroll. By supplying high-pressure lubricating oil to the oil groove, an oil film is formed on the thrust sliding surfaces of the fixed scroll and the movable scroll. Conventionally, as disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 2004-60532), a high-pressure oil introduction passage formed in the movable scroll is provided with a throttle mechanism such as a fine hole. The high-pressure oil introduction passage is a space through which high-pressure lubricating oil supplied to the thrust sliding surface passes. The throttle mechanism limits the flow rate of the lubricating oil that passes through the high-pressure oil introduction passage. As a result, even when the movable scroll rolls over during low differential pressure operation where the pressure difference between the refrigerant before compression and after compression is small, a large amount of lubricating oil enters the compression chamber from the high pressure oil introduction passage via the thrust sliding surface. Is prevented from flowing in. That is, the throttle mechanism can stably supply the lubricating oil to the thrust sliding surface of the compressor without degrading the performance of the compressor.

  However, in such a scroll compressor, the lubricating oil supplied to the oil groove gradually leaks into the compression chamber and the low-pressure space outside the compression mechanism as it flows toward the terminal end of the oil groove. Therefore, the smaller the radial seal size of the thrust sliding surface due to downsizing of the scroll compressor, etc., the more easily the lubricating oil supplied to the oil groove leaks out of the oil groove before reaching the end of the oil groove. Become. For this reason, seizure occurs in the vicinity of the oil groove end portion of the thrust sliding surface, so that the thrust sliding property of the compression mechanism may not be sufficiently secured, and the sealing property of the compression chamber may not be sufficiently secured.

  The objective of this invention is providing the scroll compressor which can improve the thrust sliding property and sealing performance of a compression mechanism.

  A scroll compressor according to a first aspect of the present invention includes a casing, a compression mechanism, and a negative pressure generation mechanism. The casing has at its bottom an oil storage part in which lubricating oil is stored. The compression mechanism is housed inside the casing. The compression mechanism has a fixed scroll and a movable scroll. The compression mechanism compresses the refrigerant. The negative pressure generating mechanism is provided in the high pressure space. The high-pressure space is a space inside the casing, and is a space to which the refrigerant compressed by the compression mechanism is supplied. The negative pressure generating mechanism generates a negative pressure region having a pressure lower than the pressure in the high pressure space using the flow of the refrigerant or the lubricating oil. The fixed scroll has an oil groove through which lubricating oil flows. The oil groove is formed to extend in the circumferential direction of the thrust sliding surface on the thrust sliding surface where the fixed scroll slides with the movable scroll. The end of the oil groove communicates with the negative pressure region.

  In this scroll compressor, an oil groove for supplying lubricating oil to the thrust sliding surfaces of the fixed scroll and the movable scroll is formed in the fixed scroll. The lubricating oil supplied to the oil groove from the oil reservoir in the high pressure space forms an oil film on the thrust sliding surface and seals the thrust sliding surface. The oil groove communicates with the high-pressure space on the side where the lubricating oil is supplied and the negative pressure region at a lower pressure than the high-pressure space. Therefore, the lubricating oil flowing through the oil groove is sucked into the negative pressure region. The lubricating oil sucked into the negative pressure region reaches the high pressure space and is finally returned to the oil reservoir.

  In this scroll compressor, the lubricating oil supplied to the oil groove from the high pressure space is sucked into the negative pressure region that is a part of the high pressure space. Therefore, by connecting the end of the oil groove with the negative pressure region, the scroll compressor suppresses the amount of lubricating oil supplied from the oil groove to the thrust sliding surface before reaching the end of the oil groove. be able to. As a result, this scroll compressor can prevent problems such as seizure of the thrust sliding surface due to insufficient supply of lubricating oil from the end of the oil groove to the thrust sliding surface. In addition, since this scroll compressor can suppress a decrease in the pressure of the lubricating oil at the end of the oil groove, it is possible to supply a lubricating oil having sufficient pressure to the thrust sliding surface near the end of the oil groove. it can. As a result, the scroll compressor can sufficiently ensure the pushing force of the lubricating oil against the movable scroll on the thrust sliding surface near the end of the oil groove. Therefore, this scroll compressor can improve the thrust slidability and sealing performance of the compression mechanism.

  A scroll compressor according to a second aspect of the present invention is the scroll compressor according to the first aspect, and the negative pressure generating mechanism is an ejector mechanism. The ejector mechanism generates a negative pressure region using the flow of lubricating oil that is supplied to the sliding portion inside the casing and then returned to the high-pressure space.

  The scroll compressor which concerns on the 3rd viewpoint of this invention is a scroll compressor which concerns on a 2nd viewpoint, Comprising: An ejector mechanism has an oil flow path formation member. The oil flow path forming member forms an oil flow path for returning the lubricating oil supplied to the sliding portion to the high pressure space. The oil passage has an oil acceleration passage and an oil suction passage. The oil acceleration channel increases the flow rate of the lubricating oil and generates a negative pressure region in the oil channel. The oil suction channel sucks the lubricating oil from the oil groove and joins the oil acceleration channel. The oil acceleration channel has a narrowed portion. The oil acceleration channel increases the flow rate of the lubricating oil that passes through the constriction.

  In this scroll compressor, the lubricating oil supplied from the oil storage portion to the sliding portion such as the bearing portion flows through the oil acceleration passage of the oil passage. As the lubricating oil passes through the narrow portion of the oil acceleration channel, the flow velocity of the lubricating oil increases. Lubricating oil with an increased flow rate generates a negative pressure region in the oil flow path due to the ejector effect. On the other hand, the oil groove formed in the fixed scroll communicates with the negative pressure region via the oil suction passage. Therefore, the lubricating oil flowing through the oil groove is sucked toward the negative pressure region, and thereby passes through the oil suction passage and is supplied to the oil passage. The lubricating oil supplied from the oil groove to the oil flow path merges with the lubricating oil flowing through the oil acceleration flow path, and is returned to the oil reservoir.

  The scroll compressor which concerns on the 4th viewpoint of this invention is a scroll compressor which concerns on a 3rd viewpoint, Comprising: The housing accommodated in the inside of a casing is further provided. The housing has an oil storage space and an oil return passage. The oil storage space stores the lubricating oil supplied to the sliding portion. In the oil return passage, lubricating oil stored in the oil storage space flows and communicates with the oil acceleration passage.

  In this scroll compressor, the lubricating oil supplied from the oil storage part to the sliding part such as the bearing part is temporarily stored in the oil storage space of the housing. The lubricating oil in the oil storage space flows through the oil return passage of the housing and is supplied to the oil acceleration passage of the oil passage.

  The scroll compressor which concerns on the 5th viewpoint of this invention is a scroll compressor which concerns on a 4th viewpoint, Comprising: A fixed scroll further has the 1st negative pressure communication path connected with the edge part of an oil groove. The housing further has a second negative pressure communication path communicating with the first negative pressure communication path and the negative pressure region.

  In this scroll compressor, the lubricating oil flowing through the oil groove first flows to the end of the oil groove, then passes through the first negative pressure communication path of the fixed scroll, and then passes through the second negative pressure communication path of the housing. Reach the negative pressure region of the oil flow path. Since the negative pressure region communicates with the end of the oil groove, the lubricating oil flowing through the oil groove tends to flow to the end of the oil groove due to the suction force toward the negative pressure region. Therefore, this scroll compressor can prevent problems such as seizure of the thrust sliding surface due to insufficient supply of lubricating oil from the end of the oil groove to the thrust sliding surface.

  A scroll compressor according to a sixth aspect of the present invention is the scroll compressor according to the fifth aspect, and the ejector mechanism further includes an oil return member and an oil suction member. The oil return member is a member for guiding the lubricating oil flowing through the oil return passage to the oil acceleration passage. The oil suction member is a member for guiding the lubricating oil flowing through the second negative pressure communication path to the oil suction passage.

  The scroll compressor which concerns on the 7th viewpoint of this invention is a scroll compressor which concerns on a 6th viewpoint, Comprising: The height position of the lower end of an oil return member is equal to the height position of the lower end of an oil suction member.

  A scroll compressor according to an eighth aspect of the present invention is the scroll compressor according to any one of the second to seventh aspects, further comprising a crankshaft. The crankshaft is housed inside the casing and drives the compression mechanism. The movable scroll has a bearing portion that rotatably supports the crankshaft. The sliding part is a sliding surface between the crankshaft and the bearing part.

  A scroll compressor according to a ninth aspect of the present invention is the scroll compressor according to any one of the first aspect to the eighth aspect, wherein the movable scroll is an oil supply fine flow through which lubricating oil supplied to the oil groove flows. Has holes. The fixed scroll further has a fueling pocket. The oil supply pocket is supplied with lubricating oil from the high-pressure space, has a cross-sectional area larger than that of the oil groove, and communicates with the oil groove. The oil supply pocket is always in communication with the oil supply hole regardless of the position of the movable scroll.

  In this scroll compressor, the lubricating oil stored in the oil storage section in the high-pressure space passes through the oil supply pores of the movable scroll, is supplied to the oil supply pocket, and then flows into the oil groove. The lubrication pocket is always in communication with the lubrication pore. Therefore, this scroll compressor can stably supply the lubricating oil to the oil groove.

  The scroll compressor according to the first to ninth aspects of the present invention can improve the thrust sliding performance and sealing performance of the compression mechanism.

It is a longitudinal cross-sectional view of the scroll compressor which concerns on embodiment of this invention. It is a bottom view of a fixed scroll. It is a top view of a movable scroll. It is a bottom view of a fixed scroll showing a thrust sliding surface and a compression chamber. It is a longitudinal cross-sectional view of an ejector mechanism. It is a longitudinal cross-sectional view of the ejector mechanism in the modification A. It is a bottom view of a fixed scroll in Modification B. It is a bottom view of a fixed scroll in Modification C.

  A scroll compressor according to an embodiment of the present invention will be described with reference to the drawings. A scroll compressor is a compressor in which a refrigerant is compressed by changing the volume of a space formed by two scroll members having spiral wraps that mesh with each other.

(1) Configuration of Scroll Compressor FIG. 1 is a longitudinal sectional view of a scroll compressor 101 according to this embodiment. The scroll compressor 101 mainly includes a casing 10, a compression mechanism 15, a housing 23, a drive motor 16, a lower bearing 60, a crankshaft 17, an ejector mechanism 91, a suction pipe 19, and a discharge pipe (see FIG. (Not shown). The scroll compressor 101 has a role of compressing refrigerant gas in a refrigerant circuit that repeats a refrigeration cycle for circulating refrigerant. Next, each component of the scroll compressor 101 will be described.

(1-1) Casing The casing 10 includes a substantially cylindrical trunk casing portion 11, a bowl-shaped upper wall portion 12 welded in an airtight manner to the upper end portion of the trunk casing portion 11, and the trunk casing portion 11. And a bowl-shaped bottom wall portion 13 which is welded in an airtight manner to the lower end portion of the base plate. The casing 10 is formed of a rigid member that is unlikely to be deformed or damaged when pressure or temperature changes inside or outside the casing 10. The casing 10 is installed so that the substantially cylindrical axial direction of the body casing portion 11 is along the vertical direction.

  Inside the casing 10, a compression mechanism 15, a housing 23 disposed below the compression mechanism 15, a drive motor 16 disposed below the housing 23, and a crankshaft 17 disposed to extend in the vertical direction. Etc. are housed. A suction pipe 19 and a discharge pipe are welded to the wall portion of the casing 10 in an airtight manner.

  An oil storage portion 10a that is a space in which the lubricating oil is stored is formed at the bottom of the casing 10. Lubricating oil is used to keep the lubricity of sliding parts such as the compression mechanism 15 good during the operation of the scroll compressor 101.

(1-2) Compression Mechanism The compression mechanism 15 is housed inside the casing 10, sucks and compresses low-temperature and low-pressure refrigerant gas, and discharges high-temperature and high-pressure refrigerant gas (hereinafter referred to as “compressed refrigerant”). . The compression mechanism 15 is mainly composed of a fixed scroll 24 and a movable scroll 26. FIG. 2 is a plan view of the fixed scroll 24 as viewed from below in the vertical direction. FIG. 3 is a plan view of the movable scroll 26 viewed from above in the vertical direction.

  The fixed scroll 24 includes a first end plate 24a and an involute-shaped first wrap 24b formed upright on the first end plate 24a. The fixed scroll 24 has a main suction hole 24c and a sub suction hole (not shown). The main suction hole 24c communicates the suction pipe 19 and a compression chamber 40 described later. A discharge hole 41 is formed in the central portion of the first end plate 24a, and an enlarged recess 42 communicating with the discharge hole 41 is formed on the upper surface of the first end plate 24a. The enlarged recess 42 is a space recessed in the upper surface of the first end plate 24a. A lid 44 is fixed to the upper surface of the fixed scroll 24 with bolts 44 a so as to close the enlarged recess 42. The fixed scroll 24 and the lid 44 are tightly sealed through a gasket (not shown). A muffler space 45 that silences the operation sound of the compression mechanism 15 is formed by covering the enlarged recess 42 with the lid 44. The fixed scroll 24 is formed with a first compressed refrigerant channel 46 that communicates with the muffler space 45 and opens on the lower surface of the fixed scroll 24.

  The movable scroll 26 has a second end plate 26a and an involute-shaped second wrap 26b formed upright on the second end plate 26a. An upper end bearing 26c is formed at the center of the lower surface of the second end plate 26a. Oil supply pores 63 are formed in the second end plate 26a. The oil supply pore 63 communicates the outer peripheral portion of the upper surface of the second end plate 26a and the space inside the upper end bearing 26c.

  The fixed scroll 24 and the movable scroll 26 are surrounded by the first end plate 24a, the first wrap 24b, the second end plate 26a, and the second wrap 26b when the first wrap 24b and the second wrap 26b are engaged with each other. A compression chamber 40 that is a space is formed. The volume of the compression chamber 40 is changed by the revolving motion of the movable scroll 26. During the revolution of the movable scroll 26, the lower surfaces of the first end plate 24 a and the first wrap 24 b of the fixed scroll 24 slide with the upper surfaces of the second end plate 26 a and the second wrap 26 b of the movable scroll 26. Hereinafter, the surface of the fixed scroll 24 that slides with the movable scroll 26 is referred to as a thrust sliding surface 24d. FIG. 4 is a bottom view of the fixed scroll 24 immediately after the compression chamber 40 sucks the refrigerant. FIG. 4 shows the planar position of the second wrap 26 b of the movable scroll 26 and the compression chamber 40. In FIG. 4, the hatched area represents the thrust sliding surface 24 d of the fixed scroll 24. In FIG. 4, the outer edge of the thrust sliding surface 24d is a circle and represents the locus of the outer edge of the second end plate 26a of the revolving movable scroll 26.

  As shown in FIG. 2, an oil groove 24e is formed in the first end plate 24a of the fixed scroll 24 so as to extend in the circumferential direction of the thrust sliding surface 24d. As shown in FIG. 4, the oil groove 24e has a C-shape that fits in the thrust sliding surface 24d of the first end plate 24a. Hereinafter, both end portions of the oil groove 24e are referred to as a first end portion 24f1 and a second end portion 24f2. The first end 24f1 is an end located on the radially outer side of the space on the main suction hole 24c side of the outermost compression chamber 40a, which is the compression chamber 40 formed on the outermost radial direction of the fixed scroll 24. The second end 24f2 is the end opposite to the first end 24f1. That is, the point in the compression chamber 40 that is located radially inward of the first end 24f1 and closest to the first end 24f1 is located radially inward of the second end 24f2 and closest to the second end 24f2. It is closer to the main suction hole 24 c than a point in the compression chamber 40. In the present embodiment, the width and depth of the oil groove 24e are constant from the first end 24f1 to the second end 24f2.

  As shown in FIG. 2, the first end plate 24a of the fixed scroll 24 is formed with an oil supply pocket 24h communicating with the oil groove 24e. The oil supply pocket 24h is formed wider than the oil groove 24e. In this embodiment, the depth of the oil supply pocket 24h is the same as the depth of the oil groove 24e, but the width of the oil supply pocket 24h is larger than the width of the oil groove 24e. The oil supply pocket 24h has a circular shape as shown in FIG. 2, but may have other shapes. In the circumferential direction of the thrust sliding surface 24d, the distance from the oil supply pocket 24h to the second end 24f2 is shorter than the distance from the oil supply pocket 24h to the first end 24f1. The oil supply pocket 24h always communicates with the oil supply holes 63 formed in the second end plate 26a when the movable scroll 26 rotates. The radius of the oil supply pocket 24 h is larger than the turning radius of the movable scroll 26. Therefore, by appropriately setting the position of the opening of the oil supply pore 63 on the surface of the second end plate 26a and the position of the oil supply pocket 24h, the oil supply pocket 24h can be used even if the movable scroll 26 moves. 63 can continue to communicate.

  The fixed scroll 24 has a first negative pressure communication path 24g. The first negative pressure communication path 24g communicates with the oil groove 24e and a second negative pressure communication path 23c described later. The end of the first negative pressure communication passage 24g on the side communicating with the oil groove 24e opens on the inner surface of the oil groove 24e in the vicinity of the first end 24f1. The end of the first negative pressure communication passage 24g on the side communicating with the second negative pressure communication passage 23c is the lower surface of the first end plate 24a and opens to the outer surface of the thrust sliding surface 24d.

(1-3) Housing The housing 23 is disposed below the compression mechanism 15. The outer peripheral surface of the housing 23 is joined to the inner surface of the casing 10 in an airtight manner. Thereby, the internal space of the casing 10 is partitioned into a high-pressure space S <b> 1 below the housing 23 and an upper space S <b> 2 that is a space above the housing 23. Although not shown, the upper space S2 communicates with the suction pipe 19 through the auxiliary suction hole. The pressure in the upper space S <b> 2 is approximately the same as the pressure of the low-pressure gas refrigerant sucked into the compression mechanism 15. The housing 23 mounts a fixed scroll 24 and sandwiches the movable scroll 26 together with the fixed scroll 24 via an Oldham joint 39. The Oldham coupling 39 is an annular member for preventing the movable scroll 26 from rotating. The Oldham joint 39 is fitted in an elliptical Oldham groove 39 a formed in the housing 23. A second compressed refrigerant channel 48 is formed through the outer periphery of the housing 23 in the vertical direction. The second compressed refrigerant channel 48 communicates with the first compressed refrigerant channel 46 on the upper surface of the housing 23, and communicates with the high-pressure space S <b> 1 on the lower surface of the housing 23.

  A crank chamber 23 a is recessed in the upper surface of the housing 23. A housing through hole 31 is formed in the housing 23. The housing through hole 31 penetrates the housing 23 in the vertical direction from the center of the bottom surface of the crank chamber 23 a to the center of the lower surface of the housing 23. Hereinafter, a portion that is a part of the housing 23 and in which the housing through hole 31 is formed is referred to as an upper bearing 32. The housing 23 is formed with an oil return passage 23b that connects the crank chamber 23a and the high-pressure space S1. The oil return passage 23b is a passage extending in the horizontal direction from the lower portion of the crank chamber 23a toward the inner peripheral surface of the casing 10. The bottom surface of the oil return passage 23b is at the same height as the bottom surface of the crank chamber 23a.

  Further, a second negative pressure communication passage 23c is formed in the outer peripheral portion of the housing 23 so as to penetrate in the vertical direction. The second negative pressure communication path 23c communicates with the first negative pressure communication path 24g and the high pressure space S1. An end portion of the second negative pressure communication passage 23 c that communicates with the first negative pressure communication passage 24 g opens in the outer peripheral portion of the upper surface of the housing 23. An end portion of the second negative pressure communication path 23 c that communicates with the high-pressure space S <b> 1 opens in the outer peripheral portion of the lower surface of the housing 23.

(1-4) Drive Motor The drive motor 16 is a brushless DC motor disposed below the housing 23. The drive motor 16 mainly includes a stator 51 that is fixed to the inner surface of the casing 10 and a rotor 52 that is disposed with an air gap provided inside the stator 51.

  The outer peripheral surface of the stator 51 is provided with a plurality of core cut portions that are notched from the upper end surface of the stator 51 to the lower end surface and at a predetermined interval in the circumferential direction. The core cut portion forms a motor cooling passage 55 that extends in the vertical direction between the body casing portion 11 and the stator 51.

  The rotor 52 is connected to the crankshaft 17 that passes through the center of rotation in the vertical direction. The rotor 52 is connected to the compression mechanism 15 via the crankshaft 17. The rotor 52 has a lower balance weight 54 attached to its lower end surface.

(1-5) Lower Bearing The lower bearing 60 is disposed below the drive motor 16. The outer peripheral surface of the lower bearing 60 is joined to the inner surface of the casing 10 in an airtight manner. The lower bearing 60 supports the crankshaft 17. An oil separation plate 73 is attached to the upper end surface of the lower bearing 60. The lower bearing 60 has an oil supply pump 17a attached to the lower end thereof.

(1-6) Crankshaft The crankshaft 17 is accommodated in the casing 10. The crankshaft 17 is arranged so that its axial direction is along the vertical direction. The crankshaft 17 has a shape in which the axial center of the upper end portion is slightly eccentric with respect to the axial center of the portion excluding the upper end portion. The crankshaft 17 has an upper balance weight 18. The upper balance weight 18 is fixed in close contact with the crankshaft 17 at a height position below the housing 23 and above the drive motor 16.

  The crankshaft 17 passes through the rotation center of the rotor 52 in the vertical direction and is connected to the rotor 52. The crankshaft 17 is connected to the movable scroll 26 by fitting the upper end of the crankshaft 17 into the upper end bearing 26c. The crankshaft 17 is supported by the upper bearing 32 and the lower bearing 60.

  The crankshaft 17 has a main oil supply passage 61 extending in the axial direction thereof. The upper end of the main oil supply passage 61 communicates with an oil chamber 83 formed by the upper end surface of the crankshaft 17 and the lower surface of the second end plate 26a. The oil chamber 83 communicates with an oil supply pocket 24h formed in the fixed scroll 24 through an oil supply hole 63 formed in the second end plate 26a. The lower end of the main oil supply passage 61 communicates with the oil storage part 10a of the high-pressure space S1 through the oil supply pump 17a.

  The crankshaft 17 has a first sub oil supply path 62 a, a second sub oil supply path 62 b, and a third sub oil supply path 62 c branched from the main oil supply path 61. The first sub oil supply passage 62a, the second sub oil supply passage 62b, and the third sub oil supply passage 62c extend in the horizontal direction. The first sub oil supply passage 62 a is open to the sliding surface between the crankshaft 17 and the upper end bearing 26 c of the movable scroll 26. The second sub oil supply passage 62 b opens in the sliding surface between the crankshaft 17 and the upper bearing 32 of the housing 23. The third sub oil supply passage 62 c is open on the sliding surface between the crankshaft 17 and the lower bearing 60.

  The lower end of the crankshaft 17 is connected to the oil supply pump 17a. The oil supply pump 17a is a positive displacement pump such as a trochoid pump. The main oil supply passage suction port 61a, which is the suction port of the oil supply pump 17a, is immersed in the lubricating oil in the oil reservoir 10a. The discharge port of the oil supply pump 17 a is connected to the main oil supply passage 61 of the crankshaft 17.

(1-7) Ejector Mechanism The ejector mechanism 91 is located below the second negative pressure communication path 23 c of the housing 23. FIG. 5 is a longitudinal sectional view of the scroll compressor 101 in the vicinity of the ejector mechanism 91. The ejector mechanism 91 includes an oil acceleration channel 95a and an oil suction channel 95b.

  The oil acceleration channel 95 a is a space mainly formed by the oil channel forming member 92 and the oil return member 96. The oil flow path forming member 92 is a plate-like member fixed in close contact with the inner wall surface of the casing 10. An oil flow path 92a that is a space between the oil flow path forming member 92 and the inner wall surface of the casing 10 is gradually narrowed from the upper side to the lower side. The oil return member 96 is an L-shaped tube attached to the housing 23. One end of the oil return member 96 is fitted in the oil return passage 23 b of the housing 23. The other end of the oil return member 96 is located in the oil flow path 92a. The oil acceleration channel 95a has a narrowed portion 94. The narrowed portion 94 is a portion where the flow cross-sectional area of the oil acceleration flow channel 95a is narrowed. In the present embodiment, the narrowed portion 94 is a space inside the oil return member 96 and a space extending in the vertical direction, as shown in FIG. The narrowed portion 94 has a smaller cross-sectional area than the oil return passage 23b. In addition, as will be described later, the oil acceleration channel 95a generates a negative pressure region 93 in the oil channel 92a. The negative pressure region 93 is a part of the high-pressure space S1, and is a lower pressure than the high-pressure space S1. As shown in FIG. 5, the negative pressure region 93 is formed in a space near the lower end of the oil return member 96.

  The oil suction channel 95 b is a space mainly formed by the oil channel forming member 92 and the oil suction member 97. The oil suction member 97 is a tube attached to the housing 23. One end of the oil suction member 97 is fitted into an opening on the lower side of the second negative pressure communication path 23 c formed in the housing 23. The other end of the oil suction member 97 is located in the oil flow path 92a. In the oil flow path 92 a, the height position of the lower end of the oil suction member 97 is equal to the height position of the lower end of the oil return member 96. The oil suction channel 95b merges with the oil acceleration channel 95a in the oil channel 92a.

(1-8) Suction Pipe The suction pipe 19 is a pipe for introducing the refrigerant of the refrigerant circuit from the outside of the casing 10 to the compression mechanism 15. The suction pipe 19 is fitted into the upper wall portion 12 of the casing 10 in an airtight manner. The suction pipe 19 penetrates the upper space S <b> 2 in the vertical direction, and an inner end portion is fitted into the fixed scroll 24.

(1-9) Discharge Pipe The discharge pipe is a pipe for discharging the compressed refrigerant from the high-pressure space S1 to the outside of the casing 10. The discharge pipe is fitted in the body casing portion 11 of the casing 10 in an airtight manner. The discharge pipe penetrates the high-pressure space S1 in the horizontal direction. The opening of the discharge pipe in the casing 10 is located in the vicinity of the housing 23.

(2) Operation of Scroll Compressor The operation of the scroll compressor 101 according to this embodiment will be described. Initially, the flow of the refrigerant | coolant which circulates through a refrigerant circuit provided with the scroll compressor 101 is demonstrated. Next, the flow of the lubricating oil inside the scroll compressor 101 will be described.

(2-1) Flow of refrigerant First, when the drive motor 16 is driven, the rotor 52 rotates. Thereby, the crankshaft 17 fixed to the rotor 52 rotates. The axial rotation movement of the crankshaft 17 is transmitted to the movable scroll 26 via the upper end bearing 26c. The axial center of the upper end portion of the crankshaft 17 is eccentric with respect to the axial center of the axial rotation motion of the crankshaft 17. The movable scroll 26 is prevented from rotating by the Oldham joint 39. Thereby, the movable scroll 26 performs a revolving motion with respect to the fixed scroll 24 without rotating.

  The low-temperature and low-pressure refrigerant before being compressed is supplied from the suction pipe 19 to the compression chamber 40 of the compression mechanism 15 via the main suction hole 24c and the sub suction hole. By the revolving motion of the movable scroll 26, the compression chamber 40 moves from the outer peripheral portion of the fixed scroll 24 toward the center portion while gradually reducing the volume. As a result, the refrigerant in the compression chamber 40 is compressed to become a compressed refrigerant. The compressed refrigerant is discharged from the discharge hole 41 to the muffler space 45, and then discharged to the high-pressure space S1 via the first compressed refrigerant channel 46 and the second compressed refrigerant channel 48. Then, the compressed refrigerant descends the motor cooling passage 55 and reaches the high pressure space S <b> 1 below the drive motor 16. Then, the compressed refrigerant reverses the flow direction and raises the air gap between the other motor cooling passage 55 and the drive motor 16. Finally, the compressed refrigerant is discharged from the discharge pipe to the outside of the scroll compressor 101.

(2-2) Flow of lubricating oil First, the drive motor 16 is driven to rotate the rotor 52. Thereby, the crankshaft 17 fixed to the rotor 52 rotates. The oil supply pump 17 a is driven by the rotation of the crankshaft 17. The oil supply pump 17 a sucks the lubricating oil in the oil reservoir 10 a from the main oil supply passage intake 61 a and discharges it to the main oil supply passage 61. The lubricating oil discharged to the main oil supply passage 61 by the oil supply pump 17 a rises in the main oil supply passage 61 toward the oil chamber 83.

  The lubricating oil that rises in the main oil supply path 61 is sequentially divided into the third auxiliary oil supply path 62c, the second auxiliary oil supply path 62b, and the first auxiliary oil supply path 62a. The lubricating oil flowing through the third auxiliary oil supply passage 62c lubricates the sliding surfaces of the crankshaft 17 and the lower bearing 60, and then is supplied to the high-pressure space S1 and returned to the oil reservoir 10a. The lubricating oil flowing through the second sub oil supply passage 62b is supplied to the high pressure space S1 and the crank chamber 23a after lubricating the sliding surface between the crankshaft 17 and the upper bearing 32 of the housing 23. The lubricating oil supplied to the high pressure space S1 is returned to the oil reservoir 10a. The lubricating oil supplied to the crank chamber 23a sequentially passes through the oil return passage 23b and the oil acceleration passage 95a, is supplied to the high-pressure space S1, and is returned to the oil reservoir 10a. The lubricating oil flowing through the first sub oil supply passage 62a is supplied to the crank chamber 23a after lubricating the sliding surfaces of the crankshaft 17 and the upper end bearing 26c of the movable scroll 26. The lubricating oil supplied to the crank chamber 23a sequentially passes through the oil return passage 23b and the oil acceleration passage 95a, is supplied to the high-pressure space S1, and is returned to the oil reservoir 10a.

  The lubricating oil that has moved up the main oil supply path 61 and reached the oil chamber 83 passes through the oil supply holes 63 of the second end plate 26 a and is supplied to the oil supply pocket 24 h of the fixed scroll 24. The lubricating oil supplied to the oil supply pocket 24h flows into the oil groove 24e. A part of the lubricating oil flowing into the oil groove 24e seals the thrust sliding surface 24d and flows into the compression chamber 40 and the upper space S2. The lubricating oil that has flowed into the compression chamber 40 and the upper space S2 is mixed with the refrigerant before being compressed in the form of minute oil droplets. The lubricating oil mixed in the compressed refrigerant is discharged from the compression chamber 40 to the high-pressure space S1 through the same path as the compressed refrigerant. The lubricant oil collides with the oil separation plate 73 after descending the motor cooling passage 55 together with the compressed refrigerant. The lubricating oil adhering to the oil separation plate 73 falls in the high-pressure space S1 and is returned to the oil reservoir 10a. Further, part of the lubricating oil flowing into the oil groove 24e flows to the first end 24f1 of the oil groove 24e. The lubricating oil that has reached the first end 24f1 seals the thrust sliding surface 24d and flows into the compression chamber 40 and the upper space S2, or the first negative pressure communication path that opens to the inner surface of the oil groove 24e. Flows into 24 g. The lubricating oil that has flowed into the first negative pressure communication path 24g passes through the second negative pressure communication path 23c and the oil suction flow path 95b in order, and merges with the lubricating oil that flows through the oil acceleration flow path 95a.

  Next, the flow of the lubricating oil in the ejector mechanism 91 will be described with reference to FIG. The lubricating oil supplied to the crank chamber 23a passes through the oil return passage 23b and flows through the oil acceleration passage 95a. In the oil acceleration channel 95a, the lubricating oil first flows inside the oil return member 96. Inside the oil return member 96, a narrowed portion 94 of the oil acceleration channel 95a is formed. The flow path of the lubricating oil flowing through the oil acceleration flow path 95a is narrowed at the narrowed portion 94. As a result, the flow velocity of the lubricating oil increases in the oil acceleration flow path 95a, so that the negative pressure region 93 is generated by the ejector effect in the oil flow path 92a where the lubricating oil has passed through the inside of the oil return member 96. Further, in the oil flow path 92a in which the negative pressure region 93 is generated, the oil suction flow path 95b joins with the oil acceleration flow path 95a. The pressure in the negative pressure region 93 is lower than the pressure in the high pressure space S1.

  The oil groove 24e formed in the fixed scroll 24 communicates with the high-pressure space S1 where the oil chamber 83 is located via the oil supply pocket 24h and the oil supply hole 63. The oil groove 24e communicates with the negative pressure region 93 having a lower pressure than the high pressure space S1 through the first negative pressure communication passage 24g, the second negative pressure communication passage 23c, and the oil suction passage 95b inside the oil suction member 97. doing. Therefore, a differential pressure is generated in the oil groove 24e. Due to this differential pressure, the lubricating oil flowing into the oil groove 24e from the oil supply pocket 24h passes through the first negative pressure communication path 24g, the second negative pressure communication path 23c, and the oil suction flow path 95b inside the oil suction member 97. , Suction toward the negative pressure region 93. The first negative pressure communication passage 24g opens on the inner surface of the oil groove 24e in the vicinity of the first end 24f1 of the oil groove 24e. Therefore, the lubricating oil flowing through the oil groove 24e is sucked toward the first end 24f1. The lubricating oil sucked from the oil groove 24e to the negative pressure region 93 merges with the lubricating oil flowing through the oil acceleration channel 95a in the oil channel 92a. The merged lubricating oil passes through the oil flow path 92a, then falls in the high-pressure space S1 and is returned to the oil reservoir 10a.

(3) Features of Scroll Compressor In the scroll compressor 101 according to the present embodiment, an oil groove 24e for supplying lubricating oil to the thrust sliding surface 24d of the fixed scroll 24 and the movable scroll 26 is provided in the fixed scroll 24. Is formed. The lubricating oil supplied from the oil reservoir 10a in the high-pressure space S1 to the oil groove 24e forms an oil film on the thrust sliding surface 24d to seal the thrust sliding surface 24d. The lubricating oil supplied from the oil reservoir 10a to the crank chamber 23a passes through the oil return passage 23b and flows through the oil acceleration passage 95a. The lubricating oil passes through the constricted portion 94 of the oil acceleration channel 95a, so that the flow velocity thereof increases. The lubricating oil whose flow velocity has increased causes the ejector mechanism 91 to generate a negative pressure region 93 in the oil passage 92a. The negative pressure region 93 communicates with the oil groove 24e via the oil suction channel 95b. That is, the oil groove 24e communicates with the high-pressure space S1 on the side to which the lubricating oil is supplied and the negative pressure region 93 having a lower pressure than the high-pressure space S1, so that the lubricating oil flowing through the oil groove 24e Suction is performed toward the negative pressure region 93 via the pressure communication path 24g, the second negative pressure communication path 23c, and the oil suction flow path 95b. The lubricating oil sucked from the oil groove 24e to the negative pressure region 93 merges with the lubricating oil flowing in the oil acceleration flow path 95a in the oil flow path 92a. The merged lubricating oil passes through the oil flow path 92a, then falls in the high-pressure space S1 and is returned to the oil reservoir 10a.

  Thus, in the scroll compressor 101, the lubricating oil supplied from the oil reservoir 10a to the oil groove 24e is sucked toward the negative pressure region 93 that is a part of the high-pressure space S1. Further, in the vicinity of the first end 24f1 of the oil groove 24e, a first negative pressure communication path 24g communicating with the negative pressure region 93 is opened on the inner surface of the oil groove 24e. Since the lubricating oil flowing through the oil groove 24e is sucked toward the opening of the first negative pressure communication path 24g, it easily flows to the first end 24f1 of the oil groove 24e. Therefore, the scroll compressor 101 can prevent problems such as seizure of the thrust sliding surface 24d due to insufficient lubricating oil being supplied from the first end 24f1 of the oil groove 24e to the thrust sliding surface 24d.

  Further, since the scroll compressor 101 can suppress a decrease in the pressure of the lubricating oil in the vicinity of the first end 24f1 of the oil groove 24e, the scroll compressor 101 has a thrust sliding surface 24d in the vicinity of the first end 24f1 of the oil groove 24e. Lubricating oil with sufficient pressure can be supplied. As a result, the scroll compressor 101 can sufficiently ensure the pushing force of the lubricating oil against the movable scroll 26 on the thrust sliding surface 24d in the vicinity of the first end 24f1 of the oil groove 24e.

  Accordingly, the scroll compressor 101 of the present embodiment can supply a sufficient amount of lubricating oil to the thrust sliding surface 24d in the vicinity of the first end 24f1 of the oil groove 24e, and thus the thrust sliding surface 24d. It is possible to effectively suppress seizure and wear.

  In the oil flow path 92 a, the height position of the lower end of the oil suction member 97 is equal to the height position of the lower end of the oil return member 96. The space immediately below the lower end of the oil return member 96 is a space into which the lubricating oil flows immediately after passing through the narrowed portion 94 of the oil acceleration channel 95a. The ejector effect due to the flow of the lubricating oil whose flow velocity is increased in the oil acceleration channel 95 a is maximized in the space immediately below the lower end of the oil return member 96. Therefore, the suction force of the negative pressure region 93 generated in the oil flow path 92 a is also maximized in the space immediately below the lower end of the oil return member 96. Therefore, by making the height position of the lower end of the oil suction member 97 the same as the height position of the lower end of the oil return member 96, the suction force received by the lubricating oil flowing through the oil groove 24e from the negative pressure region 93 is maximized. can do. Therefore, the scroll compressor 101 can supply a sufficient amount of lubricating oil to the thrust sliding surface 24d in the vicinity of the first end 24f1 of the oil groove 24e.

  As described above, the scroll compressor 101 can improve the thrust sliding property and the sealing property of the compression mechanism 15.

  Further, in the scroll compressor 101, the lubricating oil stored in the oil storage portion 10a passes through the oil supply pores 63 of the movable scroll 26, is supplied to the oil supply pocket 24h, and then flows into the oil groove 24e. The oil supply pocket 24 h is always in communication with the oil supply hole 63. Therefore, the scroll compressor 101 can stably supply the lubricating oil to the oil groove 24e.

(4) Modifications While the embodiments of the present invention have been described with reference to the drawings, the specific configuration of the present invention can be changed without departing from the scope of the present invention. Hereinafter, modifications to which the embodiment of the present invention can be applied will be described.

(4-1) Modification A
In the scroll compressor 101 according to the embodiment, the ejector mechanism 91 has an oil acceleration channel 95a in which the flow rate of the lubricating oil increases. The oil acceleration channel 95a has a narrowed portion 94 having a narrow channel cross-sectional area. In the embodiment, as shown in FIG. 5, the narrowed portion 94 is a space inside the oil return member 96 and is a space extending in the vertical direction. Further, the cross-sectional area of the narrowed portion 94 is constant in the vertical direction. However, the oil return member 96 may have other shapes.

  FIG. 6 is a longitudinal sectional view of the vicinity of the ejector mechanism 191 in the scroll compressor 101 of this modification. In FIG. 6, the same reference numerals as in FIG. 5 are used for elements having the same structure and function as those in the embodiment. The components of the ejector mechanism 191 of this modification are the same as those in the embodiment except for the oil return member 196.

  In this modification, as shown in FIG. 6, the space extending in the vertical direction in the oil return member 196 gradually has a channel cross-sectional area from the upper side to the lower side in the vertical direction. The stenosis part 194 is made smaller. The lubricating oil flowing in the space inside the oil return member 196 passes through the narrowed portion 194, and the flow velocity thereof increases. Therefore, similarly to the embodiment, a negative pressure region 93 is generated in the oil flow path 92a below the oil return member 196.

(4-2) Modification B
In the scroll compressor 101 according to the embodiment, the oil supply pocket 24h of the fixed scroll 24 is formed between the first end 24f1 and the second end 24f2 of the oil groove 24e, but is in communication with the oil groove 24e. It may be formed at the position.

  FIG. 7 is a plan view of the fixed scroll 124 as viewed from below in the vertical direction in the scroll compressor 101 of the present modification. Similarly to the fixed scroll 24 of the embodiment, the fixed scroll 124 includes a first end plate 124a, a first wrap 124b, a main suction hole 124c, an oil groove 124e, a first negative pressure communication path 124g, and an oil supply pocket 124h. have. The oil groove 124e has a first end 124f1 and a second end 124f2. In FIG. 7, the same reference numerals are used for elements having the same structure and function as the embodiment. The components of the fixed scroll 124 of this modification are the same as in the embodiment except for the oil groove 124e and the oil supply pocket 124h.

  In this modification, as shown in FIG. 7, the oil supply pocket 124h is formed in the second end portion 124f2 of the oil groove 124e. Similarly to the embodiment, in the vicinity of the first end 124f1 of the oil groove 124e, an opening of the first negative pressure communication path 124g communicating with the negative pressure region 93 is formed on the inner surface of the oil groove 124e. Yes.

(4-3) Modification C
In the scroll compressor 101 according to the embodiment, the oil groove 24e has a C shape, but may have another shape.

  FIG. 8 is a plan view of the fixed scroll 224 viewed from below in the vertical direction in the scroll compressor 101 of the present modification. As with the fixed scroll 24 of the embodiment, the fixed scroll 224 includes a first end plate 224a, a first wrap 224b, a main suction hole 224c, an oil groove 224e, a first negative pressure communication path 224g, and an oil supply pocket 224h. have. In FIG. 8, the same reference numerals are used for elements having the same structure and function as those of the embodiment. The components of the fixed scroll 224 of the present modification are the same as those in the embodiment except for the oil groove 224e and the oil supply pocket 224h.

  In the present modification, as shown in FIG. 8, the oil groove 224e has a circular shape. Similar to the embodiment, an opening of the first negative pressure communication path 224g is formed on the inner surface of the oil groove 224e. The oil supply pocket 224h is formed at a position opposite to the position where the opening of the first negative pressure communication path 224g is formed with respect to the discharge hole 41 formed at the center of the first end plate 224a.

(4-4) Modification D
In the scroll compressor 101 according to the embodiment, the ejector mechanism 91 generates the negative pressure region 93 in the high-pressure space S1 by increasing the flow rate of the lubricating oil in the oil acceleration channel 95a, and lubricates the oil flowing through the oil groove 24e. Oil is sucked into the high-pressure space S1. However, the scroll compressor 101 increases the flow rate of the compressed refrigerant discharged from the compression mechanism 15 to generate the negative pressure region 93 in the high-pressure space S1, so that the lubricating oil flowing in the oil groove 24e can reach the high-pressure space S1. You may suck.

  The scroll compressor according to the present invention can improve the thrust sliding property and the sealing property of the compression mechanism.

DESCRIPTION OF SYMBOLS 10 Casing 10a Oil storage part 15 Compression mechanism 17 Crankshaft 23 Housing 23a Crank chamber (oil storage space)
23b Oil return passage 23c Second negative pressure communication passage 24 Fixed scroll 24d Thrust sliding surface 24e Oil groove 24f1 First end (end)
24h Oil supply pocket 24g First negative pressure communication path 26 Movable scroll 26c Upper end bearing (bearing part)
63 Refueling pore 91 Ejector mechanism (negative pressure generating mechanism)
92 oil passage forming member 92a oil passage 93 negative pressure region 94 constricted portion 95a oil acceleration passage 95b oil suction passage 96 oil return member 97 oil suction member 101 scroll compressor S1 high pressure space

JP 2001-214872 A JP 2004-60532 A

Claims (9)

A casing (10) having an oil storage part (10a) in which lubricating oil is stored at the bottom;
A compression mechanism (15) housed inside the casing, having a fixed scroll (24) and a movable scroll (26), and compressing the refrigerant;
A pressure inside the casing is provided in a high-pressure space (S1) to which the refrigerant compressed by the compression mechanism is supplied, and the pressure of the high-pressure space using the flow of the refrigerant or the lubricating oil A negative pressure generating mechanism (91) for generating a negative pressure region (93) of lower pressure;
With
The fixed scroll has an oil groove (24e) formed to extend in a circumferential direction of the thrust sliding surface on a thrust sliding surface (24d) that slides with the movable scroll, and through which the lubricating oil flows. ,
An end (24f1) of the oil groove communicates with the negative pressure region;
Scroll compressor (101). The negative pressure generating mechanism is an ejector mechanism that generates the negative pressure region using the flow of the lubricating oil that is supplied to the sliding portion inside the casing and then returned to the high pressure space.
The scroll compressor according to claim 1. The ejector mechanism has an oil flow path forming member (92) that forms an oil flow path (92a) for returning the lubricating oil supplied to the sliding portion to the high pressure space,
The oil flow path is
An oil acceleration channel (95a) for increasing the flow rate of the lubricating oil and generating the negative pressure region in the oil channel;
An oil suction passage (95b) for sucking the lubricating oil from the oil groove and joining the oil acceleration passage;
Have
The oil acceleration channel has a constriction (94), and increases the flow rate of the lubricating oil passing through the constriction.
The scroll compressor according to claim 2. A housing (23) accommodated in the casing;
The housing is
An oil storage space (23a) for storing the lubricating oil supplied to the sliding portion;
The lubricating oil stored in the oil storage space flows, and an oil return passage (23b) communicating with the oil acceleration passage;
Having
The scroll compressor according to claim 3. The fixed scroll further has a first negative pressure communication path (24g) communicating with the end of the oil groove,
The housing further includes a second negative pressure communication path (23c) communicating with the first negative pressure communication path and the negative pressure region.
The scroll compressor according to claim 4. The ejector mechanism is
An oil return member (96) for guiding the lubricating oil flowing through the oil return passage to the oil acceleration passage;
An oil suction member (97) for guiding the lubricating oil flowing through the second negative pressure communication path to the oil suction flow path;
Further having
The scroll compressor according to claim 5. The height position of the lower end of the oil return member is equal to the height position of the lower end of the oil suction member,
The scroll compressor according to claim 6. A crankshaft (17) housed in the casing and driving the compression mechanism;
The movable scroll has a bearing portion (26c) that rotatably supports the crankshaft,
The sliding portion is a sliding surface between the crankshaft and the bearing portion.
The scroll compressor according to any one of claims 2 to 7. The movable scroll has an oil supply pore (63) through which the lubricant supplied to the oil groove flows.
The fixed scroll is supplied with the lubricating oil from the high-pressure space, has a cross-sectional area larger than the cross-sectional area of the oil groove, and further includes an oil supply pocket (24h) communicating with the oil groove,
The refueling pocket is always in communication with the refueling pores regardless of the position of the movable scroll.
The scroll compressor according to any one of claims 1 to 8.

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