JP2013108389A - Compressor and refrigerating device - Google Patents

Abstract

A compressor according to the present invention can effectively suppress the occurrence of oil rising.
A scroll compressor includes a casing, a compression mechanism, a crankshaft, a housing, a main oil supply passage, and an ejector mechanism. The housing 23 has an upper bearing 32 and a second compressed refrigerant channel 48 is formed. The second compressed refrigerant channel 48 guides the compressed refrigerant discharged from the compression mechanism 15 to the high-pressure space S <b> 1 inside the casing 10. The main oil supply path 61 supplies the lubricating oil stored in the oil storage part P to the upper bearing 32. The second compressed refrigerant channel 48 has a narrowed portion 94 at the end. A circumferential groove 34 and an oil return channel 35 are formed in the housing 23. The circumferential groove 34 stores the lubricating oil supplied to the upper bearing 32. The oil return channel 35 communicates with the circumferential groove 34 and opens into a space near the constricted portion 94. The ejector mechanism 91 has a refrigerant acceleration channel 95a and an oil suction channel 95b.
[Selection] Figure 6

Description

  The present invention relates to a compressor and a refrigeration apparatus.

  Conventionally, in a compressor used for an air conditioner or the like, a lubricating oil is used to improve the lubricity of a bearing portion inside the compressor. Such a compressor has a mechanism that efficiently circulates lubricating oil inside the compressor. However, oil rise may occur due to long-time operation. Oil rising is a phenomenon in which lubricating oil inside the compressor is discharged to a refrigerant circuit outside the compressor, for example, by being caught in the flow of the compressed refrigerant. If the lubricating oil in the compressor is insufficient due to oil rising, frictional heat is generated in the bearing portion inside the compressor, causing problems such as seizure of the bearing portion. Further, when the lubricating oil is discharged to the outside of the compressor due to the rising oil and the lubricating oil flows into a heat exchanger, a condenser, or the like, problems such as performance degradation and failure of these devices occur.

  Therefore, the scroll compressor disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2003-293554) has a mechanism for suppressing the occurrence of oil spill. This compressor has a structure that prevents the lubricating oil that has lubricated the sliding surface between the bearing portion of the housing and the crankshaft from leaking out from the lower end of the housing. If the lubricating oil leaks from the lower end of the housing, the lubricating oil is supplied to the high-pressure space communicating with the discharge pipe of the compressed refrigerant, which is likely to cause the oil to rise. In view of this, the housing of the compressor includes an oil supply passage that guides the lubricating oil that has lubricated the sliding surface to a crank chamber that is a space above the bearing portion of the housing.

  However, in such a compressor, if the operating frequency and operating differential pressure of the motor increase and the amount of oil supplied to the sliding surface increases, the lubricating oil excessively flows into the crank chamber. And when the amount of inflow into the crank chamber exceeds the amount of oil drained from the crank chamber, the crank chamber is filled with lubricating oil and the pressure in the crank chamber increases, so the amount of lubricating oil leaking from the lower end of the housing increases, Oil rise increases.

  The objective of this invention is providing the compressor which can suppress generation | occurrence | production of oil rising effectively.

  A compressor according to a first aspect of the present invention includes a casing, a compression mechanism, a crankshaft, a housing, an oil supply mechanism, and an ejector mechanism. The casing has an oil reservoir at the bottom for storing lubricating oil. The compression mechanism is housed inside the casing. The compression mechanism compresses the refrigerant. The crankshaft is housed inside the casing. The crankshaft drives the compression mechanism. The housing is housed inside the casing. The housing has a bearing portion. The bearing portion rotatably supports the crankshaft. The housing is formed with a compressed refrigerant flow path. The compressed refrigerant flow path guides the compressed refrigerant discharged from the compression mechanism to the high-pressure space inside the casing. The oil supply mechanism supplies lubricating oil stored in the oil storage part to the bearing part. The compressed refrigerant channel has a constriction at the end. An oil storage space and an oil return channel are further formed in the housing. The oil storage space stores the lubricating oil supplied to the bearing portion. The oil return channel communicates with the oil storage space and opens into a space near the constriction. The ejector mechanism has a refrigerant acceleration channel and an oil suction channel. The refrigerant acceleration channel increases the flow rate of the compressed refrigerant as the compressed refrigerant flows through the narrowed portion. The oil suction channel sucks lubricating oil from the oil return channel and joins the refrigerant acceleration channel.

  The compressor according to the first aspect is a high-low pressure dome type scroll compressor or the like. In this compressor, the lubricating oil stored at the bottom of the casing rises, for example, by a differential oil pressure in a vertical oil supply passage formed in the crankshaft and is supplied to the bearing portion of the housing. In this bearing portion, the housing slides with the crankshaft. Part of the lubricating oil that has lubricated the bearing is stored in an oil storage space formed in the housing. This oil storage space communicates with an oil return channel formed in the housing. On the other hand, the refrigerant circulating in the refrigerant circuit including the compressor is compressed by the compression mechanism, and then passes through the compressed refrigerant flow path formed in the housing and is supplied to the high-pressure space. In this compressed refrigerant flow path, a constriction is formed at the end on the high-pressure space side. The oil return flow path of the housing communicates with the high-pressure space near the narrowed portion.

  In this compressor, the flow rate of the compressed refrigerant discharged from the compression mechanism increases by passing through the narrowed portion of the compressed refrigerant flow path of the housing. The accelerated compressed refrigerant generates a negative pressure in the oil return channel of the housing due to the ejector effect. As a result, in the oil return channel, a suction force from the oil storage space toward the high pressure space is generated, so that the lubricating oil stored in the oil storage space is sucked into the high pressure space through the oil return channel. The sucked lubricating oil merges with the compressed refrigerant, and then falls to the oil reservoir at the bottom of the casing. In other words, the ejector mechanism of the compressor is composed of a refrigerant acceleration flow path composed of a compressed refrigerant flow path and a high-pressure space of the housing, and an oil suction flow path composed of an oil return flow path of the housing.

  In this compressor, the lubricating oil that has lubricated the bearing portion is stored in an oil storage space formed in the housing, and then immediately sucked into the high-pressure space by the ejector mechanism. Therefore, the lubricating oil that has lubricated the bearing portion does not leak into the high-pressure space from the lower end of the housing. Lubricating oil that has leaked from the lower end of the housing may be scattered toward the discharge pipe that discharges the compressed refrigerant to the outside of the casing, which is likely to cause oil to rise. Therefore, the compressor according to the first aspect can effectively suppress the occurrence of oil rising.

  The compressor which concerns on the 2nd viewpoint of this invention is a compressor which concerns on a 1st viewpoint, Comprising: Oil storage space is the circumferential groove provided in the internal peripheral surface of a bearing part.

  In the compressor according to the second aspect, the circumferential groove is formed at the lower end of the housing. The lubricating oil that has flowed down by lubricating the bearing portion of the housing is stored in the circumferential groove without leaking from the lower end of the housing into the high-pressure space.

  The compressor which concerns on the 3rd viewpoint of this invention is a compressor which concerns on a 1st viewpoint or a 2nd viewpoint, Comprising: A housing has a bush. The bush is attached to the inner peripheral surface of the bearing portion above the oil storage space and is in contact with the crankshaft.

  In the compressor according to the third aspect, the slidability between the housing and the crankshaft is improved by the bush. The bush is not attached to the seal portion below the oil storage space. Lubricating oil that flows between the crankshaft and the bush by lubrication does not leak from the lower end of the housing into the high-pressure space.

  A compressor according to a fourth aspect of the present invention is the compressor according to any one of the first aspect to the third aspect, and the housing is configured to supply the lubricating oil supplied to the bearing portion above the bearing portion. It has an oil recovery channel leading to the space.

  In the compressor according to the fourth aspect, a part of the lubricating oil supplied to the bearing portion is raised in the oil recovery passage and supplied to the space above the bearing portion. The space above the bearing portion is, for example, a concave crank chamber formed on the upper end surface of the housing. The lubricating oil that has flowed into the crank chamber passes through an oil drain passage formed in the housing and falls to the bottom of the casing.

  In this compressor, when the operating frequency of the motor and the operating differential pressure increase, the amount of oil supplied to the sliding portion increases, and there is a possibility that more lubricating oil may be supplied to the oil storage space of the housing. In addition, an excessive amount of lubricating oil is supplied to the crank chamber via the oil recovery passage. Thereby, it is possible to prevent the lubricating oil from leaking from the lower end of the housing to the high-pressure space by supplying the lubricating oil exceeding the allowable amount to the oil storage space. Therefore, the compressor according to the fourth aspect can more effectively suppress the occurrence of oil rising.

  A refrigeration apparatus according to a fifth aspect of the present invention includes the compressor according to any one of the first aspect to the fourth aspect, a condenser, an expansion mechanism, and an evaporator.

  The refrigeration apparatus according to the fifth aspect includes a compressor that can effectively suppress the occurrence of oil rising. Therefore, this refrigeration apparatus can suppress a decrease in the refrigeration capacity and the coefficient of performance of the compressor.

  The compressor according to the first to fourth aspects of the present invention can effectively suppress the occurrence of oil rising.

  The refrigeration apparatus according to the fifth aspect of the present invention can suppress a decrease in the refrigeration capacity and the coefficient of performance of the compressor.

It is a longitudinal cross-sectional view of the scroll compressor which concerns on embodiment of this invention. It is the schematic of a refrigerant circuit provided with the scroll compressor which concerns on embodiment of this invention. 1 is an external view of a housing of a scroll compressor according to an embodiment of the present invention. 1 is an external view including a longitudinal section of a housing of a scroll compressor according to an embodiment of the present invention. It is an external view of the upper part of the crankshaft of the scroll compressor which concerns on embodiment of this invention. It is a longitudinal cross-sectional view of the vicinity of the ejector mechanism of the scroll compressor which concerns on embodiment of this invention. It is an external view containing the longitudinal cross-section of the housing of the scroll compressor which concerns on the modification C of this invention.

  A compressor according to an embodiment of the present invention will be described with reference to the drawings. The compressor according to the present embodiment is a high and low pressure dome type scroll compressor. The scroll compressor is a compressor that compresses refrigerant by revolving one scroll of two scrolls meshing with each other without rotating.

(1) Configuration of Compressor The scroll compressor 101 mainly includes a casing 10, a compression mechanism 15, a motor 16, a crankshaft 17, a housing 23, and an ejector mechanism 91. The scroll compressor 101 plays a role of compressing refrigerant gas in a refrigerant circuit that repeats a refrigeration cycle in which refrigerant is circulated. FIG. 1 is a longitudinal sectional view of the scroll compressor 101. FIG. 2 is a schematic diagram of a refrigerant circuit including the scroll compressor 101, the condenser 103, the expansion mechanism 104, and the evaporator 105.

(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 are a compression mechanism 15, a housing 23 disposed below the compression mechanism 15, a 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 20 are welded to the wall portion of the casing 10 in an airtight manner.

  An oil storage portion P that is a space for storing lubricating oil is formed at the bottom of the casing 10. Lubricating oil is used to keep the lubricity of sliding portions 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 mainly includes a fixed scroll component 24 and a turning scroll component 26.

  The fixed scroll 24 has a first end plate 24a and a spiral (involute) first wrap 24b formed upright on the first end plate 24a. The fixed scroll 24 is formed with a main suction hole (not shown) and an auxiliary suction hole (not shown) adjacent to the main suction hole. The main suction hole communicates the suction pipe 19 and a compression chamber 40 described later. The auxiliary suction hole communicates a low-pressure space S2 described later and the compression chamber 40. A discharge hole 41 is formed at the center of the first end plate 24a, and an enlarged recess 42 communicating with the discharge hole 41 is formed at the upper surface of the first end plate 24a. The enlarged recess 42 is a space that is recessed in the upper surface of the first end plate 24a and extends in the horizontal direction. A lid 44 is fixed to the upper surface of the fixed scroll 24 with bolts 44 a so as to close the enlarged concave portion 42. And the muffler space 45 which consists of an expansion chamber which silences the driving | running sound of the compression mechanism 15 by covering the expansion recessed part 42 with the cover body 44 is formed. The fixed scroll 24 and the lid 44 are sealed by being brought into close contact with each other via a gasket (not shown). 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 orbiting scroll 26 includes a second end plate 26a and a spiral (involute) 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 orbiting 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. The compression chamber 40, which is a space to be formed, is formed. The volume of the compression chamber 40 is increased or decreased by the revolving motion of the orbiting scroll 26.

(1-3) Housing FIG. 3 is an external view of the housing 23. FIG. 4 is an external view including a longitudinal section of the housing 23. The housing 23 is disposed below the compression mechanism 15, and its outer peripheral surface is joined to the inner wall of the casing 10 in an airtight manner. For this reason, the inside of the casing 10 is partitioned into a high-pressure space S <b> 1 below the housing 23 and a low-pressure section S <b> 2 above the housing 23. The housing 23 mounts the fixed scroll 24 by being fixed with a bolt or the like, and sandwiches the orbiting scroll 26 together with the fixed scroll 24 via an Oldham joint 39 described later. A second compressed refrigerant channel 48 is formed through the outer peripheral portion of the housing 23 in the vertical direction. The second compressed refrigerant channel 48 communicates with the first compressed refrigerant channel 46 at the upper end surface of the housing 23, and communicates with the high-pressure space S 1 through the discharge port 49 at the lower end surface of the housing 23. The second compressed refrigerant channel 48 has a constricted portion 94 at the end on the high-pressure space S1 side that gradually decreases in cross-sectional area in the horizontal direction from above to below.

  A crank chamber S <b> 3 is recessed in the upper surface of the housing 23. Further, a housing through hole 31 is formed in the housing 23. The housing through-hole 31 is a space formed through the housing 23 in the vertical direction from the center of the bottom surface of the crank chamber S3 to the center of the lower end 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 upper bearing 32 rotatably supports the crankshaft 17. A bush 33 is attached to the inner peripheral surface of the upper bearing 32. The bush 33 is a cylindrical member whose inner surface is a sliding surface. An upper end bearing 26c of the orbiting scroll 26 is disposed in the crank chamber S3.

  In the present embodiment, the housing 23 is further formed with a circumferential groove 34, an oil return channel 35, and an oil recovery channel 36. As shown in FIG. 4, the circumferential groove 34 is an annular groove formed on the inner circumferential surface of the upper bearing 32 at a height position near the lower end surface of the housing 23. The oil return passage 35 is a passage formed in the horizontal direction at the height position where the circumferential groove 34 is formed. One end of the oil return channel 35 communicates with the circumferential groove 34, and the other end opens to the outer peripheral surface of the housing 23 and communicates with the high-pressure space S1. The oil recovery passage 36 is a passage formed in the vertical direction in the vicinity of the inner peripheral surface of the upper bearing 32. The oil recovery flow path 36 has an upper end opened to the crank chamber S <b> 3 and a lower end located above the circumferential groove 34. The lower end portion of the oil recovery passage 36 communicates with an outer peripheral groove 17a that is an annular groove formed on the outer peripheral surface of the crankshaft 17, as will be described later.

(1-4) Oldham Joint The Oldham Joint 39 is an annular member for preventing the orbiting scroll 26 from rotating. The Oldham joint 39 is fitted into an elliptical Oldham groove 23 a formed in the housing 23.

(1-5) Motor The motor 16 is a brushless DC motor housed in the casing 10 and disposed below the housing 23. The motor 16 mainly includes a stator 51 fixed to the inner wall of the casing 10 and a rotor 52 that is rotatably accommodated by providing a slight gap (air gap) inside the stator 51.

  Stator 51 includes a coil portion around which a conducting wire is wound and a laminated portion in which electromagnetic steel plates are laminated by welding or caulking, and has a coil end 53 formed above and below the coil portion. Further, the outer peripheral surface of the stator 51 is provided with a plurality of core cut portions (not shown) that are notched from the upper end surface to the lower end surface of the stator 51 and at a predetermined interval in the circumferential direction. ing. The core cut part forms a motor cooling passage 55 extending in the vertical direction between the body casing part 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. The lower surface and side surfaces of the lower balance weight 54 are covered with a lower balance cover 54a.

(1-6) Lower Bearing The lower bearing 60 is a member that is disposed below the motor 16 and is airtightly joined to the inner wall of the casing 10 on the outer peripheral surface thereof. The lower bearing 60 rotatably supports the crankshaft 17.

(1-7) Oil Separation Plate The oil separation plate 73 is a flat member housed inside the casing 10. The oil separation plate 73 is fixed to the upper end surface of the lower bearing 60.

(1-8) Crankshaft FIG. 5 is an external view of the upper portion of the crankshaft 17. The crankshaft 17 is housed inside the casing 10 and is disposed such that its axial direction is along the vertical direction. As shown in FIG. 1, the crankshaft 17 has a shape in which the shaft center of the upper end portion thereof is slightly eccentric with respect to the shaft center of the portion excluding the upper end portion. An upper balance weight 18 is fixed to the crankshaft 17 on the outer peripheral surface at a height position below the housing 23 and above the motor 16. The upper and side surfaces of the upper balance weight 18 are covered with an upper balance cover 18a.

  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 orbiting scroll 26 by fitting the upper end portion 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. That is, the outer peripheral surface of the crankshaft 17 slides with the upper end bearing 26 c, the upper bearing 32, and the lower bearing 60.

  The crankshaft 17 has a main oil supply passage 61 extending in the axial direction. 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 a sliding portion between the fixed scroll 24 and the orbiting scroll 26 (hereinafter referred to as “sliding portion of the compression mechanism 15”) through the oil supply hole 63 of the second end plate 26a, and finally Therefore, it communicates with the low pressure space S2. Further, the lower end of the main oil supply passage 61 communicates with the oil reservoir P of the high pressure space S1.

  The crankshaft 17 includes a first sub oil supply path 61 a, a second sub oil supply path 61 b, and a third sub oil supply path 61 c that branch from the main oil supply path 61. The first sub oil supply path 61 a, the second sub oil supply path 61 b, and the third sub oil supply path 61 c are each formed orthogonal to the main oil supply path 61. The first sub oil supply passage 61a opens in the outer peripheral surface of the crankshaft 17 that slides with the upper end bearing 26c. The second sub oil supply passage 61 b opens in the outer peripheral surface of the crankshaft 17 that slides with the upper bearing 32. The third sub oil supply passage 61 c opens in the outer peripheral surface of the crankshaft 17 that slides with the lower bearing 60.

  The crankshaft 17 has an outer peripheral groove 17 a that is an annular groove formed on the outer peripheral surface that slides with the upper bearing 32. The outer circumferential groove 17a is formed at a height position above the circumferential groove 34 of the housing 23 and below the second sub oil supply passage 61b. The outer circumferential groove 17 a communicates with the lower end portion of the oil recovery passage 36 of the housing 23.

(1-9) Ejector Mechanism The ejector mechanism 91 is located near the lower end of the second compressed refrigerant channel 48 of the housing 23. FIG. 6 is a longitudinal sectional view of the scroll compressor 101 in the vicinity of the ejector mechanism 91. The ejector mechanism 91 includes a refrigerant acceleration channel 95a and an oil suction channel 95b.

  The refrigerant acceleration channel 95 a is a channel that exists in the second compressed refrigerant channel 48 having the narrowed portion 94 and the high-pressure space S <b> 1 below the second compressed refrigerant channel 48. A gas guide 92 is disposed in the high-pressure space S <b> 1 below the second compressed refrigerant channel 48. The gas guide 92 is a plate-like member fixed in close contact with the inner wall surface of the casing 10. The space between the gas guide 92 and the inner wall surface of the casing 10 is open at the upper end and the lower end, and gradually decreases from the upper side to the lower side. In the refrigerant acceleration channel 95a, the refrigerant compressed by the compression mechanism 15 passes through the second compression refrigerant channel 48 and flows into the high-pressure space S1, and passes through the space between the gas guide 92 and the inner wall surface of the casing 10. It flows downward.

  The oil suction channel 95 b is a channel that exists in the high pressure space S <b> 1 below the oil return channel 35 and the second compressed refrigerant channel 48. The oil suction channel 95b merges with the refrigerant acceleration channel 95a in the high-pressure space S1. In the oil suction flow path 95b, the lubricating oil stored in the circumferential groove 34 passes through the oil return flow path 35 and flows into the high pressure space S1, and merges with the compressed refrigerant flowing through the refrigerant acceleration flow path 95a in the high pressure space S1. To do.

(1-10) Suction Pipe The suction pipe 19 is a tubular member 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 low pressure space S <b> 2 in the vertical direction, and an inner end portion is fitted in the fixed scroll 24.

(1-11) Discharge Pipe The discharge pipe 20 is a tubular member for discharging the compressed refrigerant from the high-pressure space S1 to the outside of the casing 10. The discharge pipe 20 is fitted in the body casing part 11 of the casing 10 in an airtight manner. The discharge pipe 20 penetrates the high-pressure space S <b> 1 in the horizontal direction, and an opening 20 a in the casing 10 is located in the vicinity of the housing 23.

(2) Operation of Compressor The operation of the scroll compressor 101 in 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 motor 16 is driven, the rotor 52 rotates. As a result, the crankshaft 17 fixed to the rotor 52 performs shaft rotation motion. The rotational movement of the crankshaft 17 is transmitted to the orbiting scroll 26 via the upper end bearing 26c. The shaft center of the upper end portion of the crankshaft 17 is eccentric with respect to the shaft rotational movement center of the crankshaft 17. The orbiting scroll 26 is prevented from rotating by the Oldham coupling 39. As a result, the orbiting scroll 26 performs a revolving motion with respect to the fixed scroll 24 without rotating.

  The low-temperature and low-pressure refrigerant before compression is sucked into the compression chamber 40 of the compression mechanism 15 from the suction pipe 19 via the main suction hole or from the low-pressure space S2 via the auxiliary suction hole. Due to the orbiting motion of the orbiting scroll 26, the compression chamber 40 moves from the outer peripheral portion of the fixed scroll 24 toward the center portion while gradually decreasing 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 supplied from the discharge port 49 to the high-pressure space S1 via the first compressed refrigerant channel 46 and the second compressed refrigerant channel 48. The compressed refrigerant flows downward in the space between the gas guide 92 and the body casing portion 11, then descends the motor cooling passage 55 and reaches the high-pressure space S <b> 1 below the motor 16. Then, the compressed refrigerant reverses the direction of flow and rises in the other motor cooling passages 55 and the air gap. Finally, the compressed refrigerant is discharged from the discharge pipe 20 to the outside of the scroll compressor 101.

(2-2) Flow of lubricating oil First, when the motor 16 is driven, the rotor 52 rotates. As a result, the crankshaft 17 fixed to the rotor 52 performs shaft rotation motion. When the compression mechanism 15 is driven by the rotational movement of the crankshaft 17 and the compressed refrigerant is discharged into the high-pressure space S1, the pressure in the high-pressure space S1 rises. On the other hand, the upper end of the main oil supply passage 61 communicates with the low pressure space S <b> 2 through the oil chamber 83 and the oil supply pores 63. Thereby, a pressure difference is generated between the upper end and the lower end of the main oil supply passage 61. As a result, the main oil supply passage 61 acts as an oil supply mechanism using a differential pressure pump, so that the lubricating oil stored in the oil storage portion P on the high pressure space S1 side moves up the main oil supply passage 61 to the low pressure space S2 side. To the oil chamber 83.

  The lubricating oil that has moved up the main oil supply passage 61 and reached the oil chamber 83 is supplied to the sliding portion of the compression mechanism 15 via the oil supply holes 63. The lubricating oil that has lubricated the sliding portion of the compression mechanism 15 leaks into the low-pressure space S <b> 2 and the compression chamber 40. At this time, the high-temperature and high-pressure lubricating oil heats the refrigerant before being compressed that exists in the low-pressure space S2 and the compression chamber 40. Lubricating oil is contained in the compressed refrigerant in the form of oil droplets. The lubricating oil contained 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. Then, after the lubricating oil moves down the motor cooling passage 55 together with the compressed refrigerant, a part of the lubricating oil collides with the oil separation plate 73. At this time, the lubricating oil adhering to the oil separation plate 73 falls in the high pressure space S1 and is stored in the oil storage portion P.

  On the other hand, most of the lubricating oil that moves up the main oil supply passage 61 is supplied to the first sub oil supply passage 61a, the second sub oil supply passage 61b, and the third sub oil supply passage 61c. After lubricating the sliding portion between the crankshaft 17 and the upper end bearing 26c in the lubricating oil flowing through the first sub oil supply passage 61a, the lubricating oil flowing to the lower end side of the upper end bearing 26c flows into the crank chamber S3, On the other hand, the lubricating oil that has flowed to the upper end side of the upper end bearing 26c leaks into the oil chamber 83 and merges with the lubricating oil that has risen directly in the main oil supply passage 61. The lubricating oil flowing through the second sub oil supply passage 61 b lubricates the bush 33 which is a sliding portion between the crankshaft 17 and the upper bearing 32, and then flows out to the oil recovery passage 36 and the circumferential groove 34. The lubricating oil that has flowed out into the oil recovery passage 36 moves up the oil recovery passage 36 and flows into the crank chamber S3. As will be described later, the lubricating oil that has flowed into the circumferential groove 34 is sucked into the high-pressure space S1 by the ejector mechanism 91 via the oil return passage 35. The lubricating oil flowing through the third auxiliary oil supply passage 61c lubricates the sliding portion between the crankshaft 17 and the lower bearing 60 and leaks into the high pressure space S1, then falls into the high pressure space S1 and is stored in the oil storage portion P. Is done.

  Next, a mechanism in which the ejector mechanism 91 sucks the lubricating oil that has lubricated the sliding portion between the crankshaft 17 and the upper bearing 32 into the high-pressure space S1 through the oil return passage 35 will be described. The compressed refrigerant discharged from the compression mechanism 15 flows through the refrigerant acceleration flow path 95a when passing through the ejector mechanism 91. At this time, the flow rate of the compressed refrigerant is increased by the narrowed portion 94 of the second compressed refrigerant channel 48, so that the flow velocity is increased. The refrigerant accelerating channel 95a merges with the oil suction channel 95b in the high-pressure space S1 where the compressed refrigerant has passed through the constricted portion 94, so that the refrigerant return channel 35 constituting the oil suction channel 95b is formed by the ejector effect. Negative pressure is generated. Thereby, the lubricating oil in the circumferential groove 34 communicating with the oil return channel 35 is sucked into the high-pressure space S <b> 1 through the oil return channel 35. The lubricating oil sucked into the high pressure space S1 merges with the flow of the compressed refrigerant in the refrigerant acceleration flow path 95a, and then falls in the high pressure space S1 and stored in the oil storage portion P.

(3) Features of the compressor (3-1)
In the scroll compressor 101 according to the present embodiment, the lubricating oil stored in the oil storage part P at the bottom of the casing 10 rises through the main oil supply passage 61 of the crankshaft 17 and is supplied to the sliding part in the casing 10. The Part of the lubricating oil that rises in the main oil supply passage 61 is supplied to the sliding portion between the crankshaft 17 and the upper bearing 32 via the second sub oil supply passage 61b, and lubricates the bush 33. The lubricating oil that has flowed down by lubricating the bush 33 is stored in the circumferential groove 34 and is immediately sucked into the high-pressure space S1 by the ejector mechanism 91 via the oil return passage 35. Thereafter, the lubricating oil merges with the flow of the compressed refrigerant, falls in the high-pressure space S1, and is collected in the oil reservoir P.

  In this embodiment, by providing the circumferential groove 34 on the inner circumferential surface of the upper bearing 32 of the housing 23, the lubricating oil that lubricates the bush 33 is temporarily stored in the circumferential groove 34, and the lower end ( That is, it is possible to prevent the lubricating oil from leaking out from the lower end of the sliding portion between the crankshaft 17 and the upper bearing 32 into the high-pressure space S1. The lubricating oil leaking from the lower end of the housing 23 adheres to the upper end surface of the upper balance cover 18 a that covers the upper balance weight 18 and is directed toward the opening 20 a of the discharge pipe 20 by the centrifugal force acting on the crankshaft 17. There is a risk of scattering. For this reason, when the lubricating oil leaks from the lower end of the housing 23, the oil rises easily. Therefore, in the scroll compressor 101 according to the present embodiment, by providing the circumferential groove 34 on the inner peripheral surface of the upper bearing 32 of the housing 23, it is possible to effectively suppress the occurrence of oil rising.

(3-2)
In the scroll compressor 101 according to the present embodiment, an oil recovery passage 36 is formed in the housing 23. The oil recovery passage 36 is a passage that returns the lubricating oil leaked to the lower end side out of the lubricating oil that lubricated the bush 33 to the crank chamber S3.

  In a scroll compressor in which the oil recovery passage 36 is not formed in the housing 23, when the operating frequency and operating differential pressure of the motor 16 increase and the amount of oil supplied to the bush 33 increases, the circumferential groove 34 exceeds the allowable amount. Lubricating oil may leak. In this case, the lubricating oil excessively stored in the circumferential groove 34 increases the pressure in the circumferential groove 34 and may leak out from the lower end of the housing 23. In the present embodiment, part of the lubricating oil that has lubricated the bush 33 is returned to the crank chamber S <b> 3 via the oil recovery passage 36. The lubricating oil returned to the crank chamber S3 flows into the high-pressure space S1 through an oil drain passage (not shown) formed in the housing 23, falls in the high-pressure space S1, and is stored in the oil storage portion P. . Therefore, in the scroll compressor 101 according to the present embodiment, the lubricating oil does not flow excessively into the circumferential groove 34, so that the occurrence of oil rising can be effectively suppressed.

(3-3)
In the scroll compressor 101 according to the present embodiment, the ejector mechanism 91 for lubricating the bush 33 and sucking the lubricating oil stored in the circumferential groove 34 into the high-pressure space S1 is mainly formed in the housing 23. It is composed of the second compressed refrigerant channel 48 and the oil return channel 35 and has no movable part. Therefore, in the scroll compressor 101 according to this embodiment, installation and maintenance of the ejector mechanism 91 are simple.

(4) Modification (4-1) Modification A
In the present embodiment, the scroll compressor 101 including the compression mechanism 15 including the fixed scroll component 24 and the orbiting scroll component 26 is used as the compressor, but a compressor including another type of compression mechanism is used. May be used. For example, a rotary type compressor or a screw type compressor may be used.

(4-2) Modification B
In the present embodiment, the oil recovery flow path 36 is formed in the housing 23, but the oil recovery flow path 36 may not be formed.

(4-3) Modification C
In the present embodiment, the narrowed portion 94 of the second compressed refrigerant channel 48 formed in the housing 23 is formed at the end of the second compressed refrigerant channel 48 on the high pressure space S1 side, as shown in FIG. ing. However, as shown in FIG. 7, even if the narrowed portion 194 of the second compressed refrigerant channel 148 formed in the housing 23 is formed at a height position between both ends of the second compressed refrigerant channel 148. Good. Also in the scroll compressor 201 according to this modification, the flow rate of the compressed refrigerant passing through the second compressed refrigerant channel 148 is increased, so that the lubricating oil stored in the circumferential groove 34 is oil-returned by the ejector effect. It is sucked into the high-pressure space S1 through 35. Therefore, in the scroll compressor 201 according to this modification, it is possible to effectively suppress the occurrence of oil rising.

  The compressor according to the present invention can effectively suppress the occurrence of oil rising.

DESCRIPTION OF SYMBOLS 10 Casing 15 Compression mechanism 17 Crankshaft 23 Housing 32 Upper bearing (bearing part)
33 Bush 34 Circumferential groove (oil storage space)
35 Oil return channel 36 Oil recovery channel 48 Second compressed refrigerant channel (compressed refrigerant channel)
61 Main oil supply passage (oil supply mechanism)
91 Ejector mechanism 94 Narrow part 95a Refrigerant acceleration flow path 95b Oil suction flow path 101 Scroll compressor (compressor)
103 condenser 104 expansion mechanism 105 evaporator P oil reservoir S1 high-pressure space

JP 2003-293554 A

Claims (5)

A casing (10) having an oil storage part (P) for storing lubricating oil at the bottom;
A compression mechanism (15) housed in the casing and compresses the refrigerant;
A crankshaft (17) housed in the casing and driving the compression mechanism;
A compressed refrigerant that is housed in the casing and has a bearing portion (32) that rotatably supports the crankshaft, and that guides the compressed refrigerant discharged from the compression mechanism to the high-pressure space (S1) inside the casing. A housing (23) in which a flow path (48) is formed;
An oil supply mechanism (61) for supplying lubricating oil stored in the oil storage part to the bearing part;
An ejector mechanism (91);
With
The compressed refrigerant flow path has a narrowed portion (94) at an end,
The housing includes an oil storage space (34) for storing the lubricating oil supplied to the bearing portion, and an oil return channel (35) that communicates with the oil storage space and opens into a space near the narrowed portion. Is further formed,
The ejector mechanism includes a refrigerant acceleration channel (95a) that increases the flow rate of the compressed refrigerant when the compressed refrigerant flows through the constricted portion, and the refrigerant acceleration channel that sucks lubricating oil from the oil return channel. An oil suction channel (95b) that merges,
Compressor (101). The oil storage space is a circumferential groove (34) provided on the inner peripheral surface of the bearing portion.
The compressor according to claim 1. The housing includes a bush (33) that is attached to the inner peripheral surface of the bearing portion and is in contact with the crankshaft above the oil storage space.
The compressor according to claim 1 or 2. The housing has an oil recovery passageway (36) for guiding lubricating oil supplied to the bearing portion to a space above the bearing portion.
The compressor according to any one of claims 1 to 3. A compressor according to any one of claims 1 to 4, a condenser (103), an expansion mechanism (104), and an evaporator (105).
Refrigeration equipment.

Images