Rotary compressor and refrigeration device

Abstract

The present disclosure provides a rotary compressor having an oil supply structure that minimizes fluctuations in the oil level of lubricating oil and the oil supply state even when the rotation speed of the rotary compressor fluctuates. [Solution] A rotary compressor comprising: a casing, a cylinder disposed inside the casing, a piston that rotates eccentrically inside the cylinder, a hollow shaft connected to the piston and having an internal space, an upper bearing disposed above the cylinder and supporting the shaft, a lower bearing disposed below the cylinder and supporting the shaft, a rear muffler disposed below the lower bearing, and a positive displacement pump attached to the rear muffler that discharges oil into the internal space.

Description

[Technical Field]

[0001] The present disclosure relates to a rotary compressor and a refrigeration system including the same. A rotary compressor compresses gas in a compression chamber formed in a cylinder by eccentrically rotating a roller within the cylinder. Rotary compressors generally have vanes to separate the compression chambers. Rotary compressors include a so-called rolling piston type in which a separate vane contacts the roller while the roller rotates eccentrically, a so-called swing type in which a vane formed integrally with the roller oscillates in response to the eccentric rotation of the roller, and a so-called hinge vane type in which the roller rotates eccentrically with the tip of the vane rotatably fitted in a recess on the outer circumferential surface of the roller. [Background technology]

[0002] Patent Document 1 discloses a rotary compressor including a casing, a cylinder disposed within the casing, a piston for forming a suction compression chamber within the cylinder, a shaft connected to the piston, and an upper bearing disposed above the cylinder and supporting the shaft. Patent Document 1 also discloses that an oil reservoir space for storing oil is formed in the lower part of the casing of the rotary compressor, and a main oil supply path is formed within the shaft that communicates with the oil reservoir space and allows the oil stored in the oil reservoir space to flow upward. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-197044 Summary of the Invention [Problem to be solved by the invention]

[0004] In a rotary compressor, it is desirable that the oil supply state does not change depending on the oil level of the lubricating oil and the rotation speed of the rotary compressor.

[0005] The present disclosure provides a rotary compressor having an oil supply structure that minimizes fluctuations in the oil level of lubricating oil and the oil supply state even when the rotation speed of the rotary compressor fluctuates. [Means for solving the problem]

[0006] The rotary compressor according to the first aspect comprises: A casing; a cylinder disposed inside the casing; a piston that rotates eccentrically inside the cylinder; a hollow shaft connected to the piston and having an internal space; an upper bearing disposed above the cylinder and supporting the shaft; a lower bearing disposed below the cylinder and supporting the shaft; a rear muffler disposed below the lower bearing; a positive displacement pump attached to the rear muffler and configured to discharge oil into the internal space; Equipped with.

[0007] According to the rotary compressor of the first aspect, it is possible to reduce the influence of the oil level in the lubricating oil and the rotation speed in the rotary compressor.

[0008] The rotary compressor according to the second aspect is The rotary compressor according to a first aspect is provided with a positioning mechanism that positions the rear muffler relative to the lower bearing.

[0009] According to the rotary compressor of the second aspect, by positioning the rear muffler relative to the lower bearing, it is possible to ensure coaxiality between the lower bearing and the positive displacement pump attached to the rear muffler.

[0010] The rotary compressor of the third aspect is the lower bearing has a first connection portion at a lower portion, The rear muffler has a second connection portion at an upper portion, the positioning mechanism is configured by the first connection portion and the second connection portion, In a second aspect of the rotary compressor, the first connecting portion and the second connecting portion are fitted and fixed to each other.

[0011] According to the rotary compressor of the third aspect, the rear muffler can be positioned relative to the lower bearing with a simple configuration.

[0012] The rotary compressor according to the fourth aspect is A plurality of positioning pins are provided. the lower bearing has a plurality of first insertion portions through which a plurality of positioning pins are inserted, the rear muffler has a plurality of second insertion portions through which a plurality of positioning pins are inserted, In a rotary compressor according to a second aspect, the positioning mechanism is configured by a plurality of positioning pins, a plurality of first insertion portions, and a plurality of second insertion portions.

[0013] According to the rotary compressor of the fourth aspect, the rear muffler can be positioned relative to the lower bearing in the circumferential direction of the shaft.

[0014] A rotary compressor according to a fifth aspect is the rotary compressor according to any one of the first aspect to the fourth aspect, wherein the positive displacement pump has a flange portion on an upper portion, and the flange portion is fixed to the rear muffler by bolts.

[0015] According to the rotary compressor of the fifth aspect, the positive displacement pump can be firmly fixed to the rear muffler.

[0016] A rotary compressor according to a sixth aspect is the rotary compressor according to any one of the first to fourth aspects, wherein the rear muffler has a wall portion extending in the vertical direction, and the positive displacement pump is fixed to the wall portion by bolts.

[0017] According to the rotary compressor of the sixth aspect, the positive displacement pump can be firmly fixed to the rear muffler.

[0018] A seventh aspect of the rotary compressor is the rotary compressor of the sixth aspect, wherein the positive displacement pump is attached by fitting it into the wall portion.

[0019] According to the rotary compressor of the seventh aspect, the positive displacement pump can be easily positioned relative to the rear muffler.

[0020] A rotary compressor according to an eighth aspect is the rotary compressor according to the seventh aspect, wherein the rear muffler has an opening in the wall portion that communicates with the outside of the wall portion.

[0021] According to the rotary compressor of the eighth aspect, the lubricating oil can be discharged more efficiently.

[0022] A rotary compressor according to a ninth aspect is the rotary compressor according to any one of the first aspect to the fourth aspect, wherein the positive displacement pump is attached to the rear muffler by press-fitting.

[0023] According to the rotary compressor of the ninth aspect, the positive displacement pump can be firmly fixed to the rear muffler.

[0024] A rotary compressor according to a tenth aspect is the rotary compressor according to any one of the first aspect to the ninth aspect, wherein a lower surface of the eccentric portion of the shaft slides on an upper surface of the lower bearing.

[0025] According to the rotary compressor of the tenth aspect, the shaft can be supported in the up-down direction by the upper surface of the lower bearing.

[0026] A rotary compressor according to an eleventh aspect is the rotary compressor according to any one of the first aspect to the tenth aspect, in which the positive displacement pump is a trochoid pump.

[0027] According to the rotary compressor of the eleventh aspect, the lubricating oil can be stably supplied.

[0028] A rotary compressor according to a twelfth aspect is the rotary compressor according to the eleventh aspect, wherein the trochoid pump includes a thrust plate, and a lower end of the shaft is spaced apart from the thrust plate.

[0029] According to the rotary compressor of the twelfth aspect, friction between the trochoid pump and the shaft can be suppressed.

[0030] A rotary compressor according to a thirteenth aspect is the rotary compressor according to either the eleventh or twelfth aspect, wherein a pipe is arranged in the internal space at a distance from an inner wall of the shaft, the trochoid pump includes an inner rotor, and a lower part of the pipe is fixed to the inner rotor.

[0031] According to the rotary compressor of the thirteenth aspect, the configuration can be simplified.

[0032] A rotary compressor according to a fourteenth aspect is the rotary compressor according to either the eleventh or twelfth aspect, wherein the trochoid pump includes an inner rotor, and a lower part of the shaft is fixed to the inner rotor.

[0033] According to the rotary compressor of the fourteenth aspect, the configuration can be simplified.

[0034] A refrigeration apparatus according to a first aspect is a refrigeration apparatus including the rotary compressor according to any one of the first aspect to the fourteenth aspect.

[0035] According to the refrigeration system of the first aspect, in the rotary compressor, the influence of the oil level of the lubricating oil and the rotation speed of the rotary compressor can be reduced. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 1 is a perspective view of a rotary compressor according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the rotary compressor according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view of the rotary compressor according to the first embodiment. [Figure 4] FIG. 4 is an exploded perspective view of the positive displacement pump in the rotary compressor according to the first embodiment. [Figure 5]FIG. 5 is a bottom view of the main body of the positive displacement pump in the rotary compressor according to the first embodiment. [Figure 6] FIG. 6 is a plan view of the main body of the positive displacement pump in the rotary compressor according to the first embodiment. [Figure 7] FIG. 7 is a perspective view illustrating the attachment of a positive displacement pump in the rotary compressor according to the first embodiment. [Figure 8] FIG. 8 is a plan view illustrating the operation of the positive displacement pump in the rotary compressor according to the first embodiment. [Figure 9] FIG. 9 is a cross-sectional view illustrating the flow of lubricating oil in the rotary compressor according to the first embodiment. [Figure 10] FIG. 10 is a cross-sectional view illustrating the flow of lubricating oil in a first modified example of the rotary compressor according to the first embodiment. [Figure 11] FIG. 11 is a cross-sectional view of a second modified example of the rotary compressor according to the first embodiment. [Figure 12] FIG. 12 is a cross-sectional view illustrating the flow of lubricating oil in a second modified example of the rotary compressor according to the first embodiment. [Figure 13] FIG. 13 is a cross-sectional view illustrating the flow of lubricating oil in the second modified example of the rotary compressor according to the first embodiment. [Figure 14] FIG. 14 is a cross-sectional view of a rotary compressor according to the second embodiment. [Figure 15] FIG. 15 is a cross-sectional view of a rotary compressor according to the second embodiment. [Figure 16] FIG. 16 is an exploded perspective view of a positive displacement pump in a rotary compressor according to the second embodiment. [Figure 17] FIG. 17 is a bottom view of the main body of the positive displacement pump in the rotary compressor according to the second embodiment. [Figure 18] FIG. 18 is a plan view of a main body of a positive displacement pump in a rotary compressor according to the second embodiment. [Figure 19]FIG. 19 is a cross-sectional view illustrating the flow of lubricating oil in the rotary compressor according to the second embodiment. [Figure 20] FIG. 20 is a cross-sectional view illustrating the flow of lubricating oil in a modified example of the rotary compressor according to the second embodiment. [Figure 21] FIG. 21 is a cross-sectional view illustrating a modified example of the positioning mechanism in the rotary compressor according to the embodiment of the present disclosure. [Figure 22] FIG. 22 is a cross-sectional view illustrating a modified example of the positioning mechanism in the rotary compressor according to the embodiment of the present disclosure. [Figure 23] FIG. 23 is a diagram showing an outline of a refrigeration device including a rotary compressor according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0037] First Embodiment Specific examples of the rotary compressor according to the first embodiment will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0038] In the description of the specification and drawings of each embodiment, components having substantially the same or corresponding functional configurations may be designated by the same reference numerals to avoid redundant explanation. In addition, the scale of each part in the drawings may differ from the actual scale to facilitate understanding.

[0039] In the directions of parallel, right-angle, orthogonal, horizontal, vertical, up-down, left-right, front-back, etc., deviations are permitted to the extent that they do not impair the effects of the embodiments. The shape of the corners is not limited to right angles and may be rounded. Parallel, right-angle, orthogonal, horizontal, and vertical may include approximately parallel, approximately right-angle, approximately orthogonal, approximately horizontal, and approximately vertical, respectively.

[0040] For example, "substantially parallel" means that even if two lines or two surfaces are not completely parallel to each other, they can be treated as parallel to each other within the range allowed in manufacturing. As with "substantially parallel," "substantially right angle," "substantially perpendicular," "substantially horizontal," and "substantially vertical" are also intended to fall under the respective terms as long as the relative positional relationship between the two lines or two surfaces is within the range allowed in manufacturing.

[0041] A rotary compressor according to the first embodiment will be described. The rotary compressor according to the first embodiment includes a casing, a cylinder disposed inside the casing, a piston that rotates eccentrically inside the cylinder, and a hollow shaft connected to the piston and having an internal space. The piston generally includes a circular roller and a vane that separates a compression chamber. The rotary compressor according to the first embodiment also includes an upper bearing disposed above the cylinder and supporting the shaft, a lower bearing disposed below the cylinder and supporting the shaft, a rear muffler disposed below the lower bearing, and a positive displacement pump attached to the rear muffler that discharges oil into the internal space.

[0042] Fig. 1 is a perspective view of a rotary compressor 1 which is an example of a rotary compressor according to a first embodiment. Figs. 2 and 3 are cross-sectional views of the rotary compressor 1 which is an example of a rotary compressor according to the first embodiment. Fig. 3 is an enlarged cross-sectional view of a compression section 70 in the rotary compressor 1.

[0043] For ease of explanation, the drawings may include a virtual three-dimensional coordinate system (XYZ Cartesian coordinate system) consisting of mutually orthogonal X, Y, and Z axes (XYZ axes). For example, for a coordinate axis perpendicular to the plane of the drawing, a black circle within a circle indicates that the coordinate axis faces toward the front of the plane of the paper. A cross within a circle indicates that the coordinate axis faces away from the plane of the paper.

[0044] However, this coordinate system is defined for the purpose of explanation and does not limit the attitude of the rotary compressor etc. according to this embodiment.

[0045] In the following drawings, the shaft 81 of the rotary compressor 1 extends in the direction along the Z axis, and the pistons 61 and 62 of the rotary compressor 1 rotate in a plane parallel to the XY plane including the X and Y axes.

[0046] A view of an object viewed from the +Z side in the opposite direction of the Z axis along the Z axis direction is called a top view. A view of an object viewed from the +Z side in the opposite direction of the Z axis along the Z axis direction is called a top view. A view of an object viewed from the -Z side in the direction of the Z axis along the Z axis direction is called a bottom view. A view of an object viewed from the -Z side in the direction of the Z axis along the Z axis direction is called a bottom view.

[0047] The rotary compressor 1 compresses a refrigerant. The refrigerant used in the rotary compressor 1 is, for example, carbon dioxide. The refrigerant is not limited to carbon dioxide, and may be, for example, a fluorocarbon-based, hydrofluoroolefin-based, or hydrocarbon-based refrigerant. The rotary compressor 1 includes a compressor main body 10 and an accumulator 20.

[0048] [Compressor body 10] The compressor body 10 includes a casing 11, an intake pipe 12, an exhaust pipe 13, and a power terminal 15. The casing 11 also includes a plate 14 for mounting the compressor body 10 thereon.

[0049] The compressor body 10 includes a compression section 70 and an electric motor section 80 inside a casing 11. The electric motor section 80 rotates a shaft 81. The compression section 70 compresses the refrigerant supplied from an intake pipe 12. The refrigerant compressed in the compression section 70 is discharged to the outside of the rotary compressor 1 through an exhaust pipe 13. The compression section 70 constitutes a compression mechanism.

[0050] The electric motor 80 rotates the shaft 81. The shaft 81 is connected to each of the pistons 61 and 62. In the compression section 70, the shaft 81, which is rotated by the electric motor 80, rotates each of the pistons 61 and 62. Each of the pistons 61 and 62 rotates eccentrically when the shaft 81 rotates. The rotation of each of the pistons 61 and 62 compresses the refrigerant in the compression section 70. Each of the pistons 61 and 62 is composed of a circular roller and a vane that separates the compression chamber. The shaft 81 is a hollow shaft having an internal space 81a. The shaft 81 is a hollow shaft. A tube 85 is inserted into the internal space 81a. The tube 85 is arranged spaced apart from an inner wall that forms the internal space 81a of the shaft 81.

[0051] The shaft 81 has a main shaft portion 82, an eccentric portion 83, an intermediate connecting portion 84, an eccentric portion 86, and a counter shaft portion 87. In the shaft 81, the main shaft portion 82, the eccentric portion 83, the intermediate connecting portion 84, the eccentric portion 86, and the counter shaft portion 87 are integrally formed.

[0052] The main shaft portion 82 has a columnar or cylindrical shape. The upper end of the main shaft portion 82 is connected to the rotor of the motor in the electric unit 80. The lower end of the main shaft portion 82 is rotatably supported by the upper bearing 32. The lower end of the main shaft portion 82 forms a journal.

[0053] Eccentric portion 83 is a cylindrical portion having a diameter larger than that of main shaft portion 82. The central axis of eccentric portion 83 is eccentric from the central axis of main shaft portion 82. Piston 62 is attached to eccentric portion 83.

[0054] The intermediate connecting portion 84 connects the eccentric portion 83 and the eccentric portion 86 together.

[0055] The eccentric portion 86 is a cylindrical portion with a larger diameter than the main shaft portion 82. The central axis of the eccentric portion 86 is eccentric from the central axis of the main shaft portion 82. The eccentric portion 86 is eccentric to the central axis of the main shaft portion 82 on the opposite side to the eccentric portion 83. The piston 61 is attached to the eccentric portion 86. The lower surface of the eccentric portion 86 slides against the upper surface of the lower bearing 31.

[0056] The countershaft portion 87 has a columnar or cylindrical shape. The countershaft portion 87 is rotatably supported by the lower bearing 31. The countershaft portion 87 constitutes a journal.

[0057] The compression unit 70 includes a lower bearing 31, a cylinder 41, a middle plate 33, a cylinder 42, and an upper bearing 32. The lower bearing 31, the cylinder 41, the middle plate 33, the cylinder 42, and the upper bearing 32 are stacked from bottom to top. The upper bearing 32 is disposed above the cylinders 41 and 42. The lower bearing 31 is disposed below the cylinders 41 and 42. A shaft 81 passes through the lower bearing 31, the cylinder 41, the middle plate 33, the cylinder 42, and the upper bearing 32. The lower bearing 31, the cylinder 41, the middle plate 33, the cylinder 42, and the upper bearing 32 each include an oil supply hole through which lubricating oil is supplied to the portion through which the shaft 81 passes. In addition, the shaft 81 has a communication hole that passes from an internal space 81a to the outside of the shaft 81 to supply lubricating oil to the lower bearing 31, the cylinder 41, the cylinder 42, and the upper bearing 32. Specifically, the shaft 81 has a lower bearing oil supply hole 81h1, a communication hole 81h2, a communication hole 81h3, and an upper bearing oil supply hole 81h4 for supplying lubricating oil to the lower bearing 31, the cylinder 41, the cylinder 42, and the upper bearing 32, respectively. The shaft 81 may also have a communication hole for supplying lubricating oil to the middle plate 33.

[0058] Compression section 70 includes piston 61 inside cylinder 41, which rotates eccentrically by shaft 81. The lower surface of piston 61 slides on the upper surface of lower bearing 31. The upper surface of piston 61 slides on the lower surface of middle plate 33.

[0059] Compression section 70 also includes, inside cylinder 42, piston 62 that rotates eccentrically by shaft 81. The lower surface of piston 62 slides against the upper surface of middle plate 33. The upper surface of piston 62 slides against the lower surface of upper bearing 32.

[0060] The compression section 70 also includes a rear muffler 34 that is disposed below the lower bearing 31. The compression section 70 also includes a positive displacement pump 50 that is attached to the rear muffler 34.

[0061] The compression section 70 includes a positioning mechanism 71 that positions the rear muffler 34 relative to the lower bearing 31. The positioning mechanism 71 is made up of a first connecting portion 31i and a second connecting portion 34p.

[0062] The first connection portion 31i is provided on the lower part of the lower bearing 31. In other words, the lower bearing 31 has the first connection portion 31i on its lower part. The first connection portion 31i is a recess that recesses upward (toward the +Z side) from the lower surface of the lower bearing 31. The first connection portion 31i is formed around the shaft 81.

[0063] The second connection portion 34p is provided on the upper part of the rear muffler 34. In other words, the rear muffler 34 has the second connection portion 34p on its upper part. The second connection portion 34p is a convex portion that protrudes upward (toward the +Z side) from the upper surface of the rear muffler 34. The second connection portion 34p is formed around the shaft 81.

[0064] The first connecting portion 31i and the second connecting portion 34p are fitted together. By fitting the first connecting portion 31i and the second connecting portion 34p together, the first connecting portion 31i and the second connecting portion 34p are fixed to each other.

[0065] By providing the positioning mechanism 71 in the compression section 70, it is possible to ensure coaxiality between the lower bearing 31 and the positive displacement pump 50 attached to the rear muffler 34.

[0066] (Positional displacement pump 50) A detailed description will be given of the positive displacement pump 50. Fig. 4 is an exploded perspective view of the positive displacement pump 50 in the rotary compressor 1, which is an example of the rotary compressor according to the first embodiment.

[0067] The positive displacement pump 50 discharges lubricating oil into the internal space 81a of the shaft 81. The positive displacement pump 50 is a trochoid pump. Note that in the rotary compressor according to the first embodiment, the positive displacement pump is not limited to a trochoid pump, and may be, for example, a gear pump, a vane pump, or a piston pump.

[0068] The positive displacement pump 50 is attached to the rear muffler 34. The positive displacement pump 50 includes a main body 51, an outer rotor 52, an inner rotor 53, and a thrust plate 54.

[0069] (Main body 51) The main body 51 will be described in detail. Fig. 5 is a bottom view of the main body 51 of the positive displacement pump 50 in the rotary compressor 1, which is an example of the rotary compressor according to the first embodiment. Fig. 6 is a plan view of the main body 51 of the positive displacement pump 50 in the rotary compressor 1, which is an example of the rotary compressor according to the first embodiment.

[0070] The main body 51 has a recess 51g at its upper part in which the outer rotor 52 and the inner rotor 53 are housed. The main body 51 also has a through-hole 51s that penetrates from the lower surface 51D, which is the lowest surface, to the bottom surface 51S of the recess 51g. The positive displacement pump 50 sucks the lubricating oil accumulated in the oil reservoir SP through the through-hole 51s.

[0071] The main body 51 has a recess 51g, and a bottom surface 51S of the recess 51g has a groove 51d formed therein.

[0072] The main body 51 has, at its upper portion, a plurality of flange portions 51f extending in a direction parallel to the XY plane. Each of the plurality of flange portions 51f has a through-hole 51h through which a bolt 55 passes. An outer surface 51T, which is a part of a cylindrical surface, is formed in the portion where the flange portions 51f are formed.

[0073] (Outer rotor 52) The outer rotor 52 is fixed to a recess 51g in the main body 51. The outer rotor 52 has a through hole 52h in its center, into which the inner rotor 53 is inserted. An inner surface 52S of the through hole 52h has a cross-sectional shape that forms a trochoid curve.

[0074] (Inner rotor 53) The inner rotor 53 is inserted into the through-hole 52h of the outer rotor 52. The inner rotor 53 is rotatable inside the through-hole 52h of the outer rotor 52. The outer surface 53S of the inner rotor 53 has a cross-sectional shape that forms a trochoid curve. The number of teeth on the inner rotor 53 is one less than the number of teeth on the outer rotor 52. The inner rotor 53 has a through-hole 53h in its center.

[0075] (Thrust plate 54) The thrust plate 54 is a plate for pressing the inner rotor 53. The thrust plate 54 has a through hole 54h in the center.

[0076] The following describes how the positive displacement pump 50 is attached to the rear muffler 34. Fig. 7 is a perspective view illustrating how the positive displacement pump 50 is attached to the rotary compressor 1, which is an example of the rotary compressor according to the first embodiment.

[0077] The rear muffler 34 includes a flat plate portion 34a extending in the X-axis direction and the Y-axis direction, and a wall portion 34b extending from the flat plate portion 34a along the Y-axis direction (up-down direction) in the opposite direction to the Z-axis. The wall portion 34b has an inner surface 34S.

[0078] The positive displacement pump 50 is attached by being fitted into the wall portion 34b. Specifically, the outer surface 51T of the body 51 of the positive displacement pump 50 is fitted into the inner surface 34S of the wall portion 34b, thereby attaching the positive displacement pump 50 to the wall portion 34b. The positive displacement pump 50 may also be attached by being press-fitted into the rear muffler 34.

[0079] The wall portion 34b has threaded holes 34s into which bolts 55 are inserted. The bolts 55 pass through through holes 51h in the flange portion 51f and are screwed into the threaded holes 34s in the wall portion 34b. When the bolts 55 are screwed into the threaded holes 34s, the flange portion 51f is fixed to the wall portion 34b by the bolts 55. When the flange portion 51f is fixed to the wall portion 34b by the bolts 55, the positive displacement pump 50 is fixed to the rear muffler 34.

[0080] A gap is formed in a portion where the inner surface 34S of the wall portion 34b and the outer surface 51T do not contact each other. The lubricating oil discharged into the internal space 81a of the shaft 81 is discharged from the gap into the oil reservoir SP.

[0081] Next, the operation of the positive displacement pump 50 will be described. FIG. 8 is a plan view illustrating the operation of the positive displacement pump 50 in the rotary compressor 1, which is an example of the rotary compressor according to the first embodiment. More specifically, FIG. 8 is a plan view showing a top view of the outer rotor 52 and the inner rotor 53 in the positive displacement pump 50. When the inner rotor 53 rotates in the direction of the arrowed line R relative to the outer rotor 52, the lubricating oil accumulated in the oil reservoir SP is sucked in within the range DS. The range DS is connected to the through-hole 51s. Then, the lubricating oil is discharged within the range DE. After being discharged downward, the lubricating oil passes through the groove 51d and the through-hole 53h of the inner rotor 53 and is then discharged.

[0082] As described above, when the inner rotor 53 rotates relative to the outer rotor 52, the lubricating oil is sucked through the through-hole 51s of the main body 51. The sucked lubricating oil is then transferred as the outer rotor 52 rotates. The transferred lubricating oil then passes through the through-hole 53h of the inner rotor 53 and is discharged into the internal space 81a of the shaft 81.

[0083] The flow of lubricating oil will be described in detail. Fig. 9 is a cross-sectional view illustrating the flow of lubricating oil in the rotary compressor 1, which is an example of the rotary compressor according to the first embodiment. The lubricating oil accumulated in the oil reservoir SP is sucked through the through hole 51s, as indicated by the dotted arrow line SC. The sucked lubricating oil is transferred by the rotation of the inner rotor 53 relative to the outer rotor 52. The transferred lubricating oil then passes through the groove 51d, as indicated by the dotted arrow line DC, and is discharged into the interior of the pipe 85 and into the internal space 81a of the shaft 81. The pipe 85 includes a pipe 85p and a flange portion 85f.

[0084] The lubricating oil discharged into the inside of the tube 85 of the shaft 81 passes through the inside of the tube 85 and is supplied between the internal space 81a and the tube 85, as indicated by the dotted arrow line in Fig. 3. The lubricating oil supplied between the internal space 81a and the tube 85 is supplied to the lower bearing 31, cylinder 41, cylinder 42, and upper bearing 32 from the lower bearing oil supply hole 81h1, the communication hole 81h2, the communication hole 81h3, and the upper bearing oil supply hole 81h4, respectively.

[0085] Furthermore, of the lubricating oil supplied between the internal space 81a and the pipe 85, the remaining lubricating oil that has not been supplied to the lower bearing 31, the cylinder 41, the cylinder 42, and the upper bearing 32 is discharged from the internal space 81a of the shaft 81. The lubricating oil discharged from the internal space 81a of the shaft 81 is discharged into the oil reservoir SP from the gap between the rear muffler 34 and the positive displacement pump 50, along the dotted arrowed line DR shown in FIG.

[0086] The method of discharging the lubricating oil discharged into the internal space 81a of the shaft 81 into the oil sump SP is not limited to the above example. FIG. 10 is a cross-sectional view illustrating the flow of lubricating oil in a first modified example of the rotary compressor 1, which is an example of the rotary compressor according to the first embodiment. The first modified example includes a rear muffler 134 instead of the rear muffler 34. The rear muffler 134 has an opening 134h in the wall portion 134b that communicates with the outside of the wall portion 134b in order to discharge the lubricating oil into the oil sump SP. As indicated by the dotted arrowed line DR in FIG. 10, the lubricating oil may be discharged into the oil sump SP through the opening 134h.

[0087] The compression section in the first modified example includes a positioning mechanism 171 that positions the rear muffler 134 with respect to the lower bearing 31. The positioning mechanism 171 is made up of a first connecting portion 31i and a second connecting portion 134p.

[0088] The second connection portion 134p is provided on the upper part of the rear muffler 134. In other words, the rear muffler 134 has the second connection portion 134p on its upper part. The second connection portion 134p is a convex portion that protrudes upward (toward the +Z side) from the upper surface of the rear muffler 134. The second connection portion 134p is formed around the shaft 81.

[0089] The first connecting portion 31i and the second connecting portion 134p are fitted together. By fitting the first connecting portion 31i and the second connecting portion 134p together, the first connecting portion 31i and the second connecting portion 134p are fixed together.

[0090] When the rear muffler has an opening, it is not necessary to provide a gap between the rear muffler and the positive displacement pump as in the rotary compressor 1.

[0091] 9 and 10, the lower end 81e of the shaft 81 may be disposed away from the thrust plate 54. The lower end 81e of the shaft 81 and the thrust plate 54 are spaced apart by a distance h.

[0092] In order to rotate the inner rotor 53, a lower portion of the tube 85 may be fixed to the inner rotor 53. In addition, in order to rotate the inner rotor 53, a lower portion of the shaft 81 may be fixed to the inner rotor 53.

[0093] Furthermore, in the rotary compressor according to the first embodiment, the pipe in the internal space of the shaft is not limited to the pipe 85 shown in the above example. FIG. 11 is a cross-sectional view of a rotary compressor 2, which is a second modified example of the rotary compressor 1, which is an example of the rotary compressor according to the first embodiment. FIG. 12 is a cross-sectional view illustrating the flow of lubricating oil in the second modified example of the rotary compressor 1, which is an example of the rotary compressor according to the first embodiment. FIG. 13 is a cross-sectional view illustrating the flow of lubricating oil in the second modified example of the rotary compressor 1, which is an example of the rotary compressor according to the first embodiment. The second modified example includes a pipe 185 instead of the pipe 85. The pipe 185 includes only a flange portion 85f, excluding the pipe 85p of the pipe 85. As shown in the second modified example, the rotary compressor according to the first embodiment may or may not include a pipe. Furthermore, the shape of the pipe is not limited in the rotary compressor according to the first embodiment.

[0094] The rotary compressor according to the first embodiment is provided with a positive displacement pump, and thus oil can be supplied without being restricted by the oil level of the lubricating oil or the rotation speed of the rotary compressor.

[0095] Second Embodiment A rotary compressor according to a second embodiment will be described. The rotary compressor according to the second embodiment differs from the rotary compressor according to the first embodiment in the details of the positive displacement pump. Figs. 14 and 15 are cross-sectional views of a rotary compressor 3, which is an example of a rotary compressor according to the second embodiment. Fig. 15 is an enlarged cross-sectional view of a compression section 170 in the rotary compressor 3.

[0096] (Positive displacement pump 150) A detailed description will be given of the positive displacement pump 150. Fig. 16 is an exploded perspective view of the positive displacement pump 150, which is an example of a positive displacement pump in a rotary compressor according to the second embodiment.

[0097] The positive displacement pump 150 discharges lubricating oil into the internal space 81a of the shaft 81. The positive displacement pump 150 is a trochoid pump.

[0098] The positive displacement pump 150 includes a body 151 , an outer rotor 152 , an inner rotor 153 , and a thrust plate 154 .

[0099] (Main body 151) The main body 151 will be described in detail. Fig. 17 is a bottom view of the main body 151 of the positive displacement pump 150, which is an example of the positive displacement pump in the rotary compressor according to the second embodiment. Fig. 18 is a plan view of the main body 151 of the positive displacement pump 150, which is an example of the positive displacement pump in the rotary compressor according to the second embodiment.

[0100] The main body 151 has a recess 151g at its upper part in which the outer rotor 152 and the inner rotor 153 are housed. The main body 151 also has a through-hole 151s that penetrates from a lower surface 151D, which is the lowest surface, to a bottom surface 151S of the recess 151g. The positive displacement pump 150 sucks the lubricating oil accumulated in the oil reservoir SP through the through-hole 151s.

[0101] A through-hole 151t is formed in the center of a bottom surface 151S of a recess 151g of the main body 151, penetrating to a lower surface 151D.

[0102] The main body 151 has, at its upper portion, a flange portion 151f extending in a direction parallel to the XY plane. The flange portion 151f has through holes 151h through which bolts 155 pass. The bolts 155 pass through the through holes 151h in the flange portion 151f and are screwed into the threaded holes 34s in the wall portion 34b. By screwing the bolts 155 into the threaded holes 34s, the flange portion 151f is fixed to the wall portion 34b by the bolts 155. By fixing the flange portion 151f to the wall portion 34b by the bolts 155, the positive displacement pump 150 is fixed to the rear muffler 34.

[0103] (Outer rotor 152) The outer rotor 152 is fixed to a recess 151g in the main body 151. The outer rotor 152 has a through hole 152h at its center, into which the inner rotor 153 is inserted. The inner surface of the through hole 152h has a cross-sectional shape that forms a trochoid curve.

[0104] (Inner rotor 153) The inner rotor 153 is inserted into the through-hole 152h of the outer rotor 152. The inner rotor 153 is rotatable inside the through-hole 152h of the outer rotor 152. The outer surface of the inner rotor 153 has a cross-sectional shape that forms a trochoid curve. The number of teeth on the inner rotor 153 is one less than the number of teeth on the outer rotor 152. The inner rotor 153 has a through-hole 153h in its center.

[0105] (Thrust plate 154) The thrust plate 154 is a plate for pressing the inner rotor 153. The thrust plate 154 has a through hole 154h in the center. The thrust plate 154 also has a discharge hole 154t through which the lubricating oil is discharged.

[0106] The flow of lubricating oil will be described in detail. Fig. 19 is a cross-sectional view illustrating the flow of lubricating oil in the rotary compressor according to the second embodiment. The lubricating oil accumulated in the oil reservoir SP is sucked through the through-hole 151s, as indicated by the dotted arrow line SC. The sucked lubricating oil is transferred by the rotation of the inner rotor 153 relative to the outer rotor 152. The transferred lubricating oil is then discharged into the internal space 81a of the shaft 81, as indicated by the dotted arrow line DC.

[0107] The lubricating oil discharged between the internal space 81a of the shaft 81 and the pipe 85 is supplied between the internal space 81a and the pipe 85, as indicated by the dotted arrow line in FIG. 15 . The lubricating oil supplied between the internal space 81a and the pipe 85 is supplied to the lower bearing 31, the cylinder 41, the cylinder 42, and the upper bearing 32 through the lower bearing oil supply hole 81h1, the communication hole 81h2, the communication hole 81h3, and the upper bearing oil supply hole 81h4, respectively. Of the lubricating oil supplied between the internal space 81a and the pipe 85, the remaining lubricating oil that has not been supplied to the lower bearing 31, the cylinder 41, the cylinder 42, and the upper bearing 32 is discharged into the pipe 85. The lubricating oil discharged into the pipe 85 is discharged from the internal space 81a of the shaft 81.

[0108] The lubricating oil discharged from the internal space 81a of the shaft 81 is discharged from the through-hole 151t along the dotted arrow line DR shown in FIG. 19 into the oil reservoir SP.

[0109] When the inner rotor 153 rotates relative to the outer rotor 152, lubricating oil is sucked through the through-hole 151s of the main body 151. The sucked lubricating oil is then transferred as the outer rotor 152 rotates. The transferred lubricating oil then passes through the discharge hole 154t of the inner rotor 153 and is discharged into the internal space 81a of the shaft 81.

[0110] Furthermore, in the rotary compressor according to the second embodiment, the pipe in the internal space of the shaft is not limited to the pipe 85 shown in the above example. FIG. 20 is a cross-sectional view illustrating the flow of lubricating oil in a modified example of the rotary compressor according to the second embodiment. This modified example includes a pipe 185 instead of the pipe 85. The pipe 185 includes only a flange portion 85f, excluding the pipe 85p of the pipe 85. As shown in this modified example, the rotary compressor according to the second embodiment may or may not include a pipe. Furthermore, the shape of the pipe is not limited in the rotary compressor according to the second embodiment.

[0111] The rotary compressor according to the second embodiment, like the rotary compressor according to the first embodiment, is equipped with a positive displacement pump, which allows oil to be supplied without being limited by the oil level in the lubricating oil or the rotation speed of the rotary compressor.

[0112] <Modification of positioning mechanism> A modified example of the positioning mechanism will be described. Fig. 21 is a cross-sectional view illustrating a positioning mechanism 271 which is a modified example of the positioning mechanism in the rotary compressor according to the embodiment of the present disclosure. Fig. 21 is a view showing a cross section in which the positioning mechanism 71 in Fig. 9 is changed to the positioning mechanism 271.

[0113] The positioning mechanism 271 has a first connection portion 231p that is a convex portion in the lower bearing 231 and a second connection portion 234i that is a concave portion in the rear muffler 234. The positioning mechanism 271 has the first connection portion 231p that is a convex portion instead of the first connection portion 31i that is a concave portion. The positioning mechanism 271 also has the second connection portion 234i that is a concave portion instead of the second connection portion 34p that is a convex portion.

[0114] Except for the first connection portion 231p, the lower bearing 231 has a configuration common to the lower bearing 31. Moreover, the rear muffler 234 has a configuration common to the rear muffler 34 except for the second connection portion 234i.

[0115] The positioning mechanism 271 positions the rear muffler 234 relative to the lower bearing 231. The positioning mechanism 271 is made up of a first connecting portion 231p and a second connecting portion 234i.

[0116] The first connecting portion 231p is provided on the lower part of the lower bearing 231. In other words, the lower bearing 231 has the first connecting portion 231p on its lower part. The first connecting portion 231p is a convex portion that protrudes downward (towards the -Z side) from the lower surface of the lower bearing 231. The first connecting portion 231p is formed around the shaft 81.

[0117] The second connection portion 234i is provided on the upper part of the rear muffler 234. In other words, the rear muffler 234 has the second connection portion 234i on its upper part. The second connection portion 234i is a recess that is recessed downward (toward the -Z side) from the upper surface of the rear muffler 234. The second connection portion 234i is formed around the shaft 81.

[0118] The first connecting portion 231p and the second connecting portion 234i are fitted to each other. By fitting the first connecting portion 231p and the second connecting portion 234i to each other, the first connecting portion 231p and the second connecting portion 234i are fixed to each other.

[0119] Another modified example of the positioning mechanism will be described. Fig. 22 is a cross-sectional view illustrating a positioning mechanism 371 which is a modified example of the positioning mechanism in the rotary compressor according to the embodiment of the present disclosure. Fig. 22 is a view showing a cross section in which the positioning mechanism 71 in Fig. 9 is changed to the positioning mechanism 371.

[0120] The positioning mechanism 371 has a positioning pin 372, a first insertion portion 331h in the lower bearing 331 through which the positioning pin 372 is inserted, and a second insertion portion 334h in the rear muffler 234 through which the positioning pin 372 is inserted.

[0121] The lower bearing 331 has a common configuration with the lower bearing 31 except for the first insertion portion 331h. Moreover, the rear muffler 334 has a common configuration with the rear muffler 34 except for the second insertion portion 334h.

[0122] The positioning mechanism 371 positions the rear muffler 334 relative to the lower bearing 331. The positioning mechanism 371 is made up of a plurality of positioning pins 372, a plurality of first insertion portions 331h, and a plurality of second insertion portions 334h.

[0123] The first insertion portion 331h is provided at the bottom of the lower bearing 331. In other words, the lower bearing 331 has the first insertion portion 331h at its bottom. The first insertion portion 331h is a fitting hole recessed upward (toward the +Z side) from the bottom surface of the lower bearing 331. A plurality of first insertion portions 331h are formed around the shaft 81 at equal intervals.

[0124] The second insertion portion 334h is provided in the upper part of the rear muffler 334. In other words, the rear muffler 34 has the second insertion portion 334h in the upper part. The second insertion portion 334h is a fitting hole recessed downward (toward the -Z side) from the upper surface of the rear muffler 334. A plurality of second insertion portions 334h are formed around the shaft 81 at equal intervals.

[0125] The positioning pins 372 are inserted into the corresponding first insertion portions 331h and second insertion portions 334h. The first insertion portions 331h and second insertion portions 334h are positioned by the positioning pins 372 being inserted into the corresponding first insertion portions 331h and second insertion portions 334h. At least two or more positioning pins 372, first insertion portions 331h, and second insertion portions 334h are provided, i.e., a plurality of positioning pins 372, first insertion portions 331h, and second insertion portions 334h are provided.

[0126] <Refrigeration equipment> A refrigeration apparatus including a rotary compressor according to this embodiment will be described below. Fig. 23 is a diagram showing an outline of a refrigeration apparatus 100, which is an example of a refrigeration apparatus including a rotary compressor according to this embodiment.

[0127] The refrigeration device 100 includes a compressor 101, a four-way valve 102, a heat exchanger 103, an expansion valve 104, and a heat exchanger 105. The compressor 101 is a rotary compressor according to this embodiment.

[0128] First, a case where cooling is performed by the heat exchanger 105 in the refrigeration device 100 will be described. Note that Fig. 23 shows connections in the case where cooling is performed by the heat exchanger 105 in the refrigeration device 100.

[0129] The refrigerant compressed by the compressor 101 passes through the four-way valve 102 and is supplied to the heat exchanger 103. In the heat exchanger 103, the refrigerant supplied to the heat exchanger 103 is cooled by exchanging heat with air or the like. The refrigerant cooled by the heat exchanger 103 is condensed and liquefied, and is supplied to the expansion valve 104. The expansion valve 104 reduces the pressure of the refrigerant. The reduced pressure refrigerant is supplied to the heat exchanger 105. In the heat exchanger 105, the refrigerant evaporates and becomes gas. The refrigerant discharged from the heat exchanger 105 is returned to the compressor 101 and compressed again. In the heat exchanger 105, the refrigeration device 100 cools an object by the heat of vaporization generated by the evaporation of the refrigerant.

[0130] Next, a case where heating is performed by heat exchanger 105 in refrigeration apparatus 100 will be described. Refrigerant compressed by compressor 101 passes through four-way valve 102 and is supplied to heat exchanger 105. Refrigeration apparatus 100 heats an object by supplying the compressed, high-temperature refrigerant in heat exchanger 105. The refrigerant that has undergone heat exchange in heat exchanger 105 condenses and liquefies, and is supplied to expansion valve 104. The expansion valve 104 reduces the pressure of the refrigerant. The reduced-pressure refrigerant is supplied to heat exchanger 103. In heat exchanger 103, the refrigerant evaporates by exchanging heat with air or the like. The refrigerant discharged from heat exchanger 103 passes through four-way valve 102 and returns to compressor 101, where it is compressed again.

[0131] Although the embodiments have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. Various modifications and improvements, such as combinations and substitutions with part or all of other embodiments, are possible. [Explanation of symbols]

[0132] 1, 2, 3 Rotary compressor 10 Compressor body 11 Casing 31 Lower bearing 32 Upper bearing 34 Rear muffler 41, 42 cylinders 50 positive displacement pump 52 outer rotor 53 Inner rotor 54 Thrust plate 61, 62 pistons 70 Compression section 80 Electric part 81 Shaft 81a Interior space 85, 185 tube 100 Refrigeration equipment 101 Compressor 103, 105 Heat exchanger 104 Expansion valve

Claims

1. A casing (11); Cylinders (41, 42) disposed inside the casing (11); Pistons (61, 62) that rotate eccentrically inside the cylinders (41, 42); a hollow shaft (81) connected to the pistons (61, 62) and having an internal space (81a); an upper bearing (32) disposed above the cylinders (41, 42) and supporting the shaft (81); a lower bearing (31) disposed below the cylinders (41, 42) and supporting the shaft (81); a rear muffler (34) disposed below the lower bearing (31); a positive displacement pump (50, 150) attached to the rear muffler (34) and discharging oil into the internal space (81 a); Equipped with a positioning mechanism (71, 171, 271, 371) that positions the rear muffler (34, 234, 334) relative to the lower bearing (31, 231, 331) and ensures coaxiality between the lower bearing and the positive displacement pump attached to the rear muffler; Rotary compressor (1).

2. The lower bearing (31, 231) has a first connection portion (31i, 231p) at a lower portion, The rear muffler (34, 234) has a second connection portion (34p, 234i) at an upper portion thereof, the positioning mechanism (71, 171, 271) is composed of the first connection portion (31i, 231p) and the second connection portion (34p, 234i), The first connecting portion (31i, 231p) and the second connecting portion (34p, 234i) are fitted together and fixed. A rotary compressor (1) according to claim 1.

3. having a plurality of locating pins (372); The lower bearing (331) has a plurality of first insertion portions (331h) through which a plurality of positioning pins (372) are inserted, The rear muffler (334) has a plurality of second insertion portions (334h) through which a plurality of positioning pins (372) are inserted, The positioning mechanism (371) is composed of a plurality of positioning pins (372), a plurality of first insertion portions (331h), and a plurality of second insertion portions (334h). A rotary compressor (1) according to claim 1.

4. A casing (11), Cylinders (41, 42) disposed inside the casing (11); Pistons (61, 62) that rotate eccentrically inside the cylinders (41, 42); a hollow shaft (81) connected to the pistons (61, 62) and having an internal space (81a); an upper bearing (32) disposed above the cylinders (41, 42) and supporting the shaft (81); a lower bearing (31) disposed below the cylinders (41, 42) and supporting the shaft (81); a rear muffler (34) disposed below the lower bearing (31); a positive displacement pump (50, 150) attached to the rear muffler (34) and discharging oil into the internal space (81 a); Equipped with The rear muffler (34) includes a wall portion (34b) extending in the vertical direction, The positive displacement pump (50, 150) is fixed to the wall (34b). Rotary compressor (1).

5. The positive displacement pump (50, 150) is fitted and attached to the wall portion (34b). A rotary compressor (1) according to claim 4.

6. The rear muffler (34) has an opening (134h) in the wall portion (134b) that communicates with the outside of the wall portion (134b). A rotary compressor (1) according to claim 5.

7. The positive displacement pump (50, 150) is fixed to the wall portion (34b) by bolts (55, 155). A rotary compressor (1) according to claim 4.

8. The positive displacement pump (50, 150) has a flange portion (51f, 151f) at an upper portion, The flange portion (51f, 151f) is fixed to the rear muffler (34) by bolts (55, 155). A rotary compressor (1) according to any one of claims 1 to 6.

9. The positive displacement pump (50, 150) is attached to the rear muffler (34) by press fitting. A rotary compressor (1) according to any one of claims 1 to 6.

10. The lower surface of the eccentric part of the shaft slides against the upper surface of the lower bearing (31). A rotary compressor (1) according to any one of claims 1 to 6.

11. The positive displacement pump (50, 150) is a trochoid pump (50, 150). A rotary compressor (1) according to any one of claims 1 to 6.

12. The trochoid pump (50, 150) includes a thrust plate (54, 154), The lower end of the shaft (81) is spaced apart from the thrust plate (54, 154). A rotary compressor (1) according to claim 11.

13. A tube (85, 185) is arranged in the internal space (81a) at a distance from the inner wall of the shaft (81), The trochoid pump (50, 150) includes an inner rotor (53, 153), The lower portion of the tube (85, 185) is fixed to the inner rotor (53, 153). A rotary compressor (1) according to claim 11.

14. The trochoid pump (50, 150) includes an inner rotor (53, 153), The lower part of the shaft (81) is fixed to the inner rotor (53, 153). A rotary compressor (1) according to claim 11.

15. A refrigeration system (100) comprising a rotary compressor (1) according to any one of claims 1 to 6.

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