Displacement compressor

Abstract

To obtain a displacement compressor capable of suppressing temperature drop of discharge gas discharged from a sealed container.SOLUTION: A displacement compressor comprises a sealed container, a compression mechanism fixed in the sealed container, a discharge pipe provided on one end part side of the sealed container, and an oil reservoir provided in the sealed container. The displacement compressor is also provided with a heat insulating material that insulates a space in the sealed container on the discharge pipe side with respect to a contact part between the compression mechanism and the sealed container. When the displacement compression mechanism is a scroll compressor, the heat insulating material insulates at least the space in the sealed container from an outlet portion of a discharge port provided in the compression mechanism to the discharge pipe.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a positive displacement compressor used in refrigeration cycle devices such as heat pump type water heaters and air conditioners. [Background technology]

[0002] An example of a positive displacement compressor used in refrigeration cycle devices such as heat pump water heaters and air conditioners is described in JP 2009-2224 A (Patent Document 1). Patent Document 1 describes a scroll compressor in which a heat insulating material is provided on the side of the end plate in the fixed scroll opposite the wrap. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-2224 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned Patent Document 1 describes how, by installing an insulating material on the opposite side of the wrap of the end plate of the fixed scroll, even during high-speed, high-pressure differential operation when the discharge temperature is high, heat transfer from the high-temperature working fluid to the fixed scroll end plate is suppressed, and the temperature rise of the fixed scroll is suppressed. In addition, deformation due to thermal expansion of the fixed scroll end plate and fixed scroll wrap is suppressed, thereby preventing contact between the orbiting scroll and the fixed scroll and preventing an increase in input and seizure.

[0005] However, the temperature of the high-temperature working fluid discharged from the discharge port formed in the fixed scroll drops due to heat radiation from the surface of the sealed container (case) before it reaches the discharge pipe (discharge tube) provided in the sealed container. For this reason, when the positive displacement compressor described in Patent Document 1 is used in a water heater or an air conditioner, no consideration is given to the reduction in the heating capacity of the water heater or the heating capacity of the air conditioner.

[0006] An object of the present invention is to provide a positive displacement compressor capable of suppressing a decrease in temperature of a working fluid discharged from a sealed container. [Means for solving the problem]

[0007] In order to achieve the above object, the positive displacement compressor of the present invention comprises a sealed container, a compression mechanism fixed to the sealed container, and a discharge pipe provided on one end side of the sealed container for discharging working fluid discharged from the compression mechanism to the outside of the sealed container, and is characterized in that a thermal insulating material is provided to insulate the space within the sealed container on the discharge pipe side of the contact portion between the compression mechanism and the sealed container.

[0008] Another feature of the displacement type compressor of the present invention is that it comprises a sealed container, a compression mechanism fixed to the sealed container, a discharge pipe provided at an upper part of the sealed container for discharging the working fluid discharged from the compression mechanism to the outside of the sealed container, and an oil sump provided at the bottom of the sealed container, and a thermal insulating material is arranged to insulate the space within the sealed container on the opposite side of the compression mechanism from the oil sump. Effect of the Invention

[0009] According to the present invention, it is possible to obtain a positive displacement compressor capable of suppressing a decrease in the temperature of the gas discharged from the sealed container. [Brief description of the drawings]

[0010] [Figure 1] 1 is a vertical cross-sectional view showing a first embodiment of a displacement compressor of the present invention. [Diagram 2]2 is a cross-sectional view taken along the line II-II in FIG. 1, illustrating a state in which the fixed scroll and the orbiting scroll shown in FIG. 1 are engaged with each other. FIG. [Diagram 3] FIG. 4 is a vertical sectional view of a displacement type compressor showing a modified example of the first embodiment. [Figure 4] FIG. 4 is a vertical cross-sectional view showing a second embodiment of a displacement compressor according to the present invention. [Diagram 5] 5 is a cross-sectional view taken along the line VV in FIG. 4, illustrating the arrangement of the rollers, cylinders, and vanes shown in FIG. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, specific embodiments of the displacement compressor of the present invention will be described with reference to the drawings. In each drawing, the same reference numerals denote the same or corresponding parts. EXAMPLES

[0012] A first embodiment of the displacement type compressor of the present invention will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a vertical cross-sectional view showing the first embodiment of the displacement type compressor of the present invention, and Fig. 2 is a cross-sectional view taken along the line II-II in Fig. 1, showing a state in which the fixed scroll and the orbiting scroll shown in Fig. 1 are engaged with each other. Note that the heat insulating material 32 shown in Fig. 1 is omitted in Fig. 2. The positive displacement compressor of the present embodiment 1 described below is a scroll compressor used in refrigeration cycle devices such as water heaters, air conditioners, etc. First, the overall configuration of the scroll compressor as a positive displacement compressor will be described with reference to Figs. 1 and 2.

[0013] As shown in FIG. 1, the scroll compressor 1 in this embodiment is of a vertical type, and contains a compression mechanism section 3, a motor section 4, etc. inside a sealed container (case) 2. A suction pipe 5 and a discharge pipe 6 are provided at the upper part, which is one end side, of the sealed container 2 so as to penetrate the sealed container 2.

[0014] The compression mechanism 3 is composed of a frame 9, a fixed scroll 7 fixed to the frame 9, an orbiting scroll 8 meshing with the fixed scroll 7 to form a compression chamber 13, and an Oldham ring 12 that prevents the orbiting scroll 8 from rotating and orbits it. The frame 9 is fixed by means of welding 21 or the like while being in contact with the inner surface of the sealed container 2. Therefore, the outer circumferential surface of the frame 9 forms the contact surface with the sealed container 2.

[0015] The rotation of the motor unit 4 rotates the orbiting scroll 8 via the crankshaft (rotating shaft) 10, gradually decreasing the volume of the compression chamber 13 and performing a compression operation. With this compression operation, the refrigerant gas, which is the working fluid, is sucked from the suction pipe 5 and sucked into the suction chamber 20 (see also FIG. 2) via the suction port 14 provided in the fixed scroll 7. The refrigerant gas sucked into the suction chamber 20 undergoes a compression process in which it is gradually compressed in the compression chamber 13, and is discharged from the discharge port 15 provided in the approximate center of the fixed scroll 7 into a discharge space 16.

[0016] In this embodiment, the discharge space 16 is composed of a first discharge space 16a and a second discharge space 16b. Between the first discharge space 16a and the second discharge space 16b, a discharge cover 11 is provided so as to face the discharge port 15, and the discharge cover 11 is fixed to a plurality of discharge cover holders 17 provided on the upper part (discharge pipe 6 side) of the fixed scroll 7. An opening 19 is formed between the plurality of discharge cover holders 17, and the first discharge space 16a and the second discharge space 16b communicate with each other via the opening 19.

[0017] The refrigerant gas discharged from the discharge port 15 is discharged into the first discharge space 16a, and then passes through the second discharge space 16b, which is the discharge space 16 at the upper part of the sealed container 2 that is connected to the first discharge space 16a, and is discharged from the discharge pipe 6 to the refrigeration cycle (condenser side) outside the sealed container 2.

[0018] The fixed scroll 7 includes a disk-shaped base plate 7a, a spiral-shaped fixed wrap (hereinafter, simply referred to as wrap) 7b erected on the base plate 7a, a fixed tooth bottom (hereinafter, simply referred to as tooth bottom) 7c which is a spiral sliding surface on the surface of the base plate 7a between the fixed wraps 7b, and a support part 7d located on the outer periphery of the base plate 7a and provided in a cylindrical shape so as to surround the fixed wrap 7b. A mirror plate surface 7e is formed on the support part 7d, and the height of the mirror plate surface 7e is configured to be approximately the same as the height of the tooth tip 7f which is the tip surface of the fixed wrap 7b. The mirror plate surface 7e is a sliding surface where the support part 7d of the fixed scroll 7 comes into contact with the mirror plate 8a of the orbiting scroll 8.

[0019] The fixed scroll 7 has its support portion 7d fixed to the frame 9 by a bolt or the like, and the frame 9 which integrally fixes the fixed scroll 7 is fixed to the sealed container 2 by a fixing means such as the welding 21.

[0020] The orbiting scroll 8 is disposed opposite the fixed scroll 7, and the spiral fixed wrap 7b of the fixed scroll 7 and the spiral orbiting wrap (hereinafter simply referred to as wrap) 8b of the orbiting scroll 8 are meshed with each other, and the orbiting scroll 8 is rotatably mounted within the frame 9.

[0021] This rotating scroll 8 has a rotating tooth bottom (hereinafter simply referred to as the tooth bottom) 8c, which is a spiral sliding surface between rotating wraps 8b on a circular plate 8a, rotating wraps 8b erected from the rotating tooth bottom 8c, and a rotating boss portion 8d provided in the center of the back surface of the plate 8a. The surface of the outer periphery of the end plate 8 a which comes into contact with the fixed scroll 7 serves as an end plate surface 8 e of the orbiting scroll 8 .

[0022] An oil reservoir 25 for storing lubricating oil (hereinafter also referred to as oil) is provided at the bottom of the sealed container 2 accommodating the compression mechanism unit 3, the motor unit 4, etc. The motor unit 4 is composed of a stator 4a fixed to the inner surface of the sealed container 2, and a rotor 4b fixed integrally to a crankshaft 10. The crankshaft 10 is rotatably supported by a main bearing 9a provided in a frame 9, and is coaxial with the central axis of the fixed scroll 7.

[0023] An eccentric crank portion 10a is provided at the tip of the crankshaft 10, and this crank portion 10a is inserted into a rotating bearing 8g provided on the rotating boss portion 8d of the rotating scroll 8, so that the rotating scroll 8 is configured to be able to rotate as the crankshaft 10 rotates.

[0024] The central axis of the orbiting scroll 8 is offset by a predetermined distance (orbital radius) from the central axis of the fixed scroll 7. The wrap 8b of the orbiting scroll 8 is overlapped with the wrap 7b of the fixed scroll 7 while being shifted by a predetermined angle (generally 180 degrees) in the circumferential direction. The Oldham ring 12 allows the orbiting scroll 8 to orbit relatively to the fixed scroll 7 while restraining the orbiting scroll 8 from rotating on its axis.

[0025] FIG. 2 shows the state in which the fixed scroll 7 and the rotating scroll 8 shown in FIG. 1 are engaged with each other. In this figure, the rotating wrap 8b of the rotating scroll 8 is shown in cross section, and the portion corresponding to the outer periphery of the end plate 8a of the rotating scroll 8 is shown by a two-dot chain line (imaginary line).

[0026] 2, a plurality of crescent-shaped compression chambers 13 (inner orbiting compression chamber 13a, outer orbiting compression chamber 13b) are formed between the fixed wrap 7b and the orbiting wrap 8b, and when the orbiting scroll 8 is orbited, the volume of each compression chamber 13 is continuously reduced as it moves toward the center, thereby performing a compression operation. The inner orbiting compression chamber 13a is a compression chamber formed inside the orbiting wrap 8b, and the outer orbiting compression chamber 13b is a compression chamber formed outside the orbiting wrap 8b.

[0027] The suction chamber 20 is a space in the middle of sucking in the refrigerant gas. The suction chamber 20 becomes the compression chamber 13 when the phase of the orbiting motion of the orbiting scroll 8 advances and the trapping of the fluid is completed.

[0028] 1 and 2, the suction port 14 is provided in the fixed scroll 7. The suction port 14 is drilled on the outer circumferential side of the base plate 7a of the fixed scroll 7 so as to communicate with the suction chamber 20. The discharge port 15 is formed in the base plate 7a of the fixed scroll 7 near the center of the scroll so as to communicate with the compression chamber 13 on the innermost periphery side.

[0029] 1 causes the crankshaft 10 to rotate, the orbiting scroll 8 orbits with a predetermined orbital radius around the central axis of the fixed scroll 7. As a result, the refrigerant gas sucked from the suction port 14 is compressed in sequence in each compression chamber 13, and the compressed refrigerant gas is discharged from the discharge port 15 to the first discharge space 16a, then flows through the opening 19 into the second discharge space 16b, and is then supplied from the discharge pipe 6 to, for example, a refrigeration cycle outside the compressor.

[0030] Oil is supplied to each sliding part such as the main bearing 9a and the slewing bearing 8g by a differential pressure oil supply structure. That is, the inside of the sealed container 2 is at discharge pressure, and the oil sump 25 at the bottom of the sealed container 2 is also at discharge pressure. The differential pressure oil supply structure is a structure in which the oil under high pressure in the oil sump 25 is pumped up by utilizing the pressure difference with the pressure in the back pressure chamber (pressure between the discharge pressure and the suction pressure). Therefore, the lubricating oil in the oil sump 25 is sucked from the lubricating oil suction port 10c provided at the bottom of the crankshaft 10 by the pressure difference, and is sent to the top of the crankshaft 10 through the oil supply hole 10b formed so as to penetrate the crankshaft 10 in the axial direction.

[0031] Part of the lubricating oil flows through the oil supply hole 10b and is supplied to the auxiliary bearing 23 supporting the lower part of the crankshaft 10 via a horizontal hole 10d formed in the crankshaft 10. The oil that lubricates the auxiliary bearing 23 is then returned to an oil reservoir 25 at the bottom of the sealed container 2. The rest of the lubricating oil that flows through the oil supply hole 10b flows into the main bearing 9a via a horizontal hole 10e provided in the crankshaft 10, and flows into the orbiting bearing 8g through an upper space 24 of the crankshaft 10 to lubricate these sliding parts. Thereafter, the flow of the oil is throttled as it passes through minute gaps between the bearing parts of the main bearing 9a and the orbiting bearing 8g, and the oil is decompressed and expanded, and flows into the back pressure chamber 18.

[0032] When the back pressure increases, the lubricating oil that has flowed into the back pressure chamber 18 flows through a back pressure valve 31 (described later) into the suction chamber 20 and the compression chamber 13 to lubricate the wrap sliding surfaces and wrap tip gaps of the spiral fixed wrap 7b and the orbiting wrap 8b, and is also used for sealing between the compression chambers 13. The lubricating oil is then discharged together with the refrigerant gas from the discharge port 15 into the first discharge space 16a. At that time, the lubricating oil and the refrigerant gas collide with the discharge cover 11 that forms the first discharge space 16a, and are separated from each other. The lubricating oil and the refrigerant gas then change their flow directions sideways and flow into the second discharge space 16b from the opening 19. The refrigerant gas that has flowed into the second discharge space 16b is then discharged from the discharge pipe 6 to the refrigeration cycle, etc. Meanwhile, the lubricating oil separated from the refrigerant gas flows along the bottom of the second discharge space 16b from the outer periphery of the fixed scroll 7, through a passage (not shown) formed between the outer periphery of the fixed scroll 7 and frame 9 and the inner periphery of the sealed container 2, and returns to the oil reservoir 25 at the bottom of the sealed container 2 via the motor chamber 27 (27a: upper motor chamber, 27b: lower motor chamber).

[0033] Next, the function of the back pressure chamber 18 will be described. In the scroll compressor 1, an axial force (pull-out force) that tries to pull the fixed scroll 7 and the orbiting scroll 8 apart from each other is generated due to the compression action. When the two scrolls are pulled apart by this axial force, that is, when the so-called separation phenomenon of the orbiting scroll 8 occurs, the airtightness of the compression chamber 13 deteriorates, and the efficiency of the scroll compressor 1 decreases.

[0034] Therefore, the back pressure chamber 18, which has a pressure (intermediate pressure) between the discharge pressure and the suction pressure, is provided on the back side of the end plate 8a of the orbiting scroll 8, and the pressure (back pressure) of this back pressure chamber 18 cancels the separating force and presses the orbiting scroll 8 against the fixed scroll 7. In order to adjust this back pressure, in the scroll compressor of this embodiment, a back pressure valve 31 is provided on the support portion 7d of the fixed scroll 7. When the back pressure becomes high, the lubricating oil that has entered the back pressure chamber 18 pushes up this valve and flows out into the suction chamber 20 or the compression chamber 13. This makes it possible to prevent the back pressure from rising abnormally and to maintain the back pressure at an appropriate value.

[0035] The basic configuration of the scroll compressor has been described above. Next, important features of this embodiment will be described. Vertical scroll compressors as positive displacement compressors include a top discharge structure in which the refrigerant gas (working fluid) compressed in the compression mechanism flows out from the top of the sealed container 2, and a side discharge structure in which the refrigerant gas flows out from the side of the sealed container 2.

[0036] The scroll compressor of this embodiment employs a top discharge structure. In a scroll compressor with a top discharge structure, the discharge pipe 6 is provided at the top, which is one end side, of the sealed container 2, and the compressed working fluid is discharged from the discharge port 15 to the first discharge space 16a, collides with the discharge cover 11 and is separated from the oil, then passes through the second discharge space 16b and is discharged outside the compressor from the discharge pipe 6 located above.

[0037] On the other hand, in the scroll compressor with the lateral discharge structure, the discharge pipe 6 is provided on the side of the sealed container 2 in the upper motor chamber 27a. Therefore, the refrigerant gas discharged above the compression mechanism 3 flows into the upper motor chamber 27a through passages provided on the outer periphery of the fixed scroll 7 and the frame 9, and after the refrigerant gas and oil are separated by centrifugal force or the like caused by the rotation of the rotor 4b, the refrigerant gas is discharged to the refrigeration cycle through the discharge pipe provided in the sealed container 2 so that one end of the discharge pipe is exposed in the upper motor chamber 27a.

[0038] For this reason, in a scroll compressor with a lateral discharge structure, high-temperature refrigerant gas discharged from the discharge port 15 flows into the motor chamber 27, restricting heat dissipation from the motor section 4 and reducing motor efficiency. In addition, since the high-temperature refrigerant gas also flows into the lower motor chamber 27b, the oil in the oil reservoir 25 at the bottom of the sealed container 2 is also heated, and the heated oil flows into the back pressure chamber 18.

[0039] Furthermore, when the high-temperature refrigerant gas flows into the upper motor chamber 27a, the lower surface side of the frame 9 constituting a part of the compression mechanism 3 is heated by the high-temperature refrigerant gas. As a result, the back pressure chamber 18 inside the frame 9 is also heated, and the temperature inside the back pressure chamber rises. Therefore, the oil in the back pressure chamber 18 increases in temperature and flows into the suction chamber 20 and the compression chamber 13, heating the refrigerant gas flowing into the compression mechanism 3, causing a heating loss and reducing the compressor efficiency.

[0040] In addition, the high-temperature refrigerant gas discharged from the discharge port 15 heats the motor unit 4, the lubricating oil, the underside of the frame 9, etc., thereby lowering the temperature of the refrigerant gas itself. If the temperature of the refrigerant gas discharged from the discharge pipe 6 drops, the amount of heat dissipated in the condenser of the refrigeration cycle decreases, and the heating capacity of the water heater or the heating capacity of the air conditioner decreases.

[0041] In contrast, in this embodiment, a scroll compressor with a top discharge structure is used, so that the high-temperature refrigerant gas discharged from the discharge port 15 passes only through the discharge space 16 and is discharged from the discharge pipe 6 to the refrigeration cycle. This makes it possible to suppress the temperature drop of the refrigerant gas and the occurrence of heating loss, which are caused by the above-mentioned side discharge structure.

[0042] In this embodiment, a scroll compressor with a top discharge structure is used to suppress the temperature drop of the refrigerant gas and the occurrence of heating loss. Furthermore, in this embodiment, taking into consideration that high-temperature refrigerant gas flows through the discharge space 16, the following configuration is used to suppress heat dissipation from the high-temperature refrigerant gas to the outside through the sealed container 2.

[0043] In this embodiment, as shown in FIG. 1, a heat insulating material 32 is provided on the outer periphery of the sealed container 2 so as to at least insulate the discharge space 16, i.e., the space inside the sealed container from the outlet of the discharge port 15 to the discharge pipe 6. In this embodiment, the installation range of the heat insulating material 32 is preferably set to a range that can insulate the space inside the sealed container (discharge space 16) on the discharge pipe 6 side from the contact portion (contact surface) between the sealed container 2 and the compression mechanism unit 3, so as to suppress heat radiation from the high-temperature refrigerant gas discharged from the discharge port 15. In addition, no heat insulating material is provided on the motor chamber 27 side, so that heat radiation from the motor unit 4 and the oil reservoir 25 is not hindered. Furthermore, in this embodiment, no heat insulating material is provided on the outer periphery of the sealed container 2 in the frame 9, so that heat radiation from the frame 9 is not hindered.

[0044] That is, an oil reservoir 25 is provided at the bottom of the sealed container 2, and a discharge space 16 is provided on the opposite side of the oil reservoir 25 across the compression mechanism 3. In this discharge space, a discharge pipe 6 is provided, and the space inside the sealed container on the opposite side of the oil reservoir 25 across the compression mechanism 3 is insulated.

[0045] With this configuration, the high-temperature refrigerant gas discharged from the discharge port 15 is insulated by the insulating material 32, so that the heat radiation from the refrigerant gas through the surface of the sealed container 2 can be suppressed. Therefore, the temperature drop of the discharged refrigerant gas can be suppressed, so that a volumetric compressor can be obtained that can suppress the decrease in heating capacity and space heating capacity. Therefore, the temperature of the refrigerant gas flowing from the discharge pipe 6 to the condenser side of the refrigeration cycle can be maintained at a high temperature, so that the heating capacity of a heat pump water heater and the heating capacity of an air conditioner can be improved. The volumetric compressor of this embodiment is particularly suitable for the above-mentioned heat pump water heater, and is also very effective when applied to air conditioners such as air conditioners for cold regions and dedicated heating units that require a large heating capacity. In addition, since the motor chamber 27 side is not insulated, heat radiation from the motor section 4 and the oil reservoir 25 is not impeded. Therefore, the temperature rise of the motor section 4 and the oil reservoir 25 is suppressed, and the decrease in compressor efficiency due to the increase in heat loss can also be suppressed.

[0046] In this embodiment, the heat insulating material 32 made of a heat insulating cover is installed on the outer periphery of the sealed container 2. That is, the heat insulating material 32 shown in Fig. 1 is made up of a body heat insulating material 32a provided so as to cover the outer periphery of the body of the sealed container 2, and a lid-shaped heat insulating material 32b provided so as to cover the end of the sealed container 2 on the discharge pipe 6 side. Also, by attaching the lid-shaped heat insulating material 32b using the discharge pipe 6 and the suction pipe 5, the entire heat insulating material 32 can be fixed.

[0047] 1, for example, a cloth-like insulating material may be wrapped around the outer circumferential surface of the sealed container 2 and fixed with a string. Furthermore, the insulating material 32 may be configured by applying a heat insulating paint to the inner or outer circumferential surface of the sealed container 2.

[0048] Even when providing such insulation, in order to insulate the area around the discharge space 16, it is preferable to arrange the insulation 32 so as to insulate the discharge space 16 located approximately above (on the discharge pipe 6 side) the axial contact surface (corresponding to the II-II cross section in Figure 1) between the fixed scroll 7 and the frame 9, and to not provide insulation approximately below (on the opposite discharge pipe side) the axial contact surface between the fixed scroll 7 and the frame 9.

[0049] The heat insulating material may be phenolic resin fiber, polyethylene resin or phenolic resin foamed plastic heat insulating material, butyl rubber, etc. When using a flexible heat insulating material, it is recommended to wrap it around the sealed container and secure it with a string, etc. When using a non-flexible heat insulating material such as a phenolic resin foamed plastic heat insulating material, it is recommended to mold it and cover the sealed container 2. As the heat insulating paint, it is preferable to use a paint containing hollow ceramic particles. (Modification) A modified example of the above-mentioned embodiment 1 will be described with reference to Fig. 3. Fig. 3 is a vertical sectional view of a displacement type compressor showing a modified example of embodiment 1, in which parts with the same reference numerals as in Fig. 1 and Fig. 2 indicate the same or corresponding parts, and a description of the same parts will be omitted, and different parts will be mainly described.

[0050] The modification shown in Fig. 3 differs from the scroll compressor shown in Fig. 1 in that a soundproof cover 33 is provided over the entire compressor except for the bottom part of the scroll compressor 1. When providing the soundproof cover 33 in this manner, as shown in Fig. 3, it is preferable that the heat insulating material 32 is provided only around the discharge space 16 as in the case shown in Fig. 1, and the soundproof cover 33 is disposed on the outside of the heat insulating material 32.

[0051] 3, by providing a soundproof cover 33 on the outside of the heat insulating material 32, it is possible to reduce noise generated from the scroll compressor 1 while suppressing heat radiation from the discharge space 16. Note that it is preferable to use phenol resin fiber, butyl rubber, or the like as the material for the soundproof cover.

[0052] In addition, when the material constituting the soundproof cover 33, such as phenolic resin fiber or butyl rubber, itself has a certain degree of heat insulating function, the soundproof cover may be integrally formed so as to function as the heat insulating material as well. When the soundproof cover and the heat insulating material are integrally formed, the thickness of the soundproof cover is increased only around the discharge space 16 to enhance the heat insulating property, and the heat radiation from the refrigerant gas in the discharge space 16 can be suppressed.

[0053] When a soundproof cover made of a material having a heat insulating function is used to integrally function as both the heat insulating material and the soundproof cover, the thickness of the soundproof cover around the discharge space 16 is made greater than the thickness of the soundproof cover for other parts (on the side opposite the discharge pipe) such as the motor unit 4 and the oil reservoir 25. By making such a configuration, it is possible to suppress heat dissipation from the discharge space 16 and reduce the noise generated by the scroll compressor 1 while ensuring necessary heat dissipation from the motor unit 4 and the oil reservoir 25. The other configuration is similar to that of the scroll compressor 1 shown in FIGS. EXAMPLES

[0054] Next, an embodiment in which a rotary compressor is used as the positive displacement compressor will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a vertical cross-sectional view showing a second embodiment of the positive displacement compressor of the present invention, and Fig. 5 is a cross-sectional view taken along the arrows VV in Fig. 4, showing the arrangement of the rollers, cylinders, and vanes shown in Fig. 4. Note that the heat insulating material 59 shown in Fig. 4 is omitted in Fig. 5.

[0055] 4 is a vertical cross-sectional view showing a rotary compressor of the second embodiment. The rotary compressor (positive displacement compressor) 41 is configured by accommodating a compression mechanism section 43, a motor section 44, and the like in a sealed container (case) 42. The motor section 44 is configured by including a stator 44a fixed to the sealed container 42, and a rotor 44b fixed integrally to a crankshaft (rotating shaft) 45. The compression mechanism section 43 is directly connected to the motor section 44 via the crankshaft 45, and includes two sets of compression sections, a first compression section and a second compression section.

[0056] The first compression section is composed of a main bearing 46 that supports the crankshaft 45, a first cylinder 47a, a partition plate 51, a first roller 48a, a first vane 49a, a first spring 50a, etc. The second compression section is composed of the partition plate 51, a second cylinder 47b, an auxiliary bearing 52 that supports the crankshaft 45, a second roller 48b, a second vane 49b, a second spring 50b, etc.

[0057] The partition plate 51 is provided between the first cylinder 47a and the second cylinder 47b, and the main bearing 46 is disposed on the upper end surface side of the first cylinder 47a, and the sub-bearing 52 is disposed on the lower end surface side of the second cylinder 47b, thereby forming two spaces surrounded by these as compression chambers. The main bearing 46 and the partition plate 51 function as end plates for the first cylinder 47a, and the sub-bearing 52 and the partition plate 51 function as end plates for the second cylinder 47b. The main bearing 46 is fixed to the sealed container 42 by means of welding or the like, and divides the inside of the sealed container 42 into a compression mechanism section 43 side and a motor chamber 53 (53a: upper motor chamber, 53b: lower motor chamber) side. The main bearings fixed to the sealed container support the cylinders (first cylinder 47a, second cylinder 47b), the sub-bearing 52, and the like.

[0058] The crankshaft 45 is supported near its center by the main bearing 46, with the lower side of the crankshaft 45 extending toward the compression mechanism 43 and the upper side extending toward the motor 44. In addition, an oil supply hole 45c is provided that penetrates vertically along the central axis of the crankshaft 45. This oil supply hole 45c is formed to supply oil from an oil reservoir 54 at the bottom of the sealed container 42 to the sliding parts of the compression mechanism 43.

[0059] The crankshaft 45 has a first crank portion 45a and a second crank portion 45b that is 180 degrees out of phase with the first crank portion 45a. The first roller 48a is rotatably fitted to the first crank portion 45a, and the second roller 48b is rotatably fitted to the second crank portion 45b. By configuring the two compression portions to be 180 degrees out of phase with each other in this manner, the compression mechanism 43 can be well balanced and vibration can be reduced.

[0060] Next, the specific configuration and operation of the above-mentioned first compression section and second compression section will be described with reference to Figures 4 and 5. Figure 5 shows the arrangement of rollers 48, cylinder 47, and vanes 49 shown in Figure 4.

[0061] The first roller 48a (second roller 48b) rotates eccentrically in the first cylinder 47a (second cylinder 47b) in accordance with the rotation of the crankshaft 45. The first vane 49a (second vane 49b) is pressed against the first roller 48a (second roller 48b) by the gas pressure of the discharge pressure in the sealed container 42 and the first spring 50a (second spring 50b), and divides the cylinder chamber into a suction chamber 61 and a compression chamber 62. The first vane 49a (second vane 49b) reciprocates in the vane slot 60 of the cylinder 47 following the eccentric rotation of the first roller 48a (second roller 48b).

[0062] In such a configuration, the compression operation is performed as follows. When the motor unit 44 is energized, the rotor 44b drives the crankshaft 45, and the first roller 48a (second roller 48b) fitted to the first crank portion 45a (second crank portion 45b) rotates eccentrically in the first cylinder 47a (second cylinder 47b). As a result, the refrigerant gas (working fluid) passes from the suction pipe 57b through the suction port 63 and is sucked into the suction chamber 61. After the suction is completed, the suction chamber 61 becomes the compression chamber 62, and the refrigerant gas is compressed in the compression chamber 62 and discharged through the discharge port 64 and a discharge valve (not shown) provided at the discharge port 64.

[0063] As shown in Fig. 4, the rotary compressor 41 is provided with an accumulator 57 to prevent the liquefied working fluid from being directly sucked into the suction chamber 61. The refrigerant gas flowing in from an inlet 57a of the accumulator 57 is separated into liquid and gas inside the accumulator 57, and only the gaseous refrigerant gas flows from a suction pipe 57b through a suction port 63 and into the suction chamber 61 as shown in Fig. 5.

[0064] The refrigerant gas discharged from the discharge port 64 of the first compression section is discharged into the discharge space 56a in the first discharge cover 55a, and then flows out from the outflow hole 65 formed in the first discharge cover 55a to the motor chamber 53 (53a: upper motor chamber, 53b: lower motor chamber) side. The refrigerant gas flowing out to the motor chamber 53 side is discharged from the discharge pipe 58 provided above the sealed container 42 to the refrigeration cycle outside the compressor.

[0065] The refrigerant gas discharged from the discharge port of the second compression section is discharged into the discharge space 56b in the second discharge cover 55b, passes through a through hole 66 that communicates the discharge space 56a in the first discharge cover 55a with the discharge space 56b in the second discharge cover 55b, flows into the discharge space 56a in the first discharge cover 55a, and then flows out from the outflow hole 65 to the motor chamber 53. The through hole 66 is formed so as to penetrate the main bearing 46, the first cylinder 47a, the partition plate 51, the second cylinder 47b, and the sub-bearing 52.

[0066] The refrigerant gas flowing out from the first compression section and the second compression section to the motor chamber 53 side is mixed and discharged from a discharge pipe 58 provided at the top of the sealed container 42 to a condenser (not shown) side of the refrigeration cycle outside the compressor. Here, the refrigerant gas containing the lubricating oil is discharged outside the compressor from the discharge pipe 58 after the lubricating oil is separated therefrom by the effect of centrifugal separation caused by the rotation of the rotor 44b of the motor section 44. The separated lubricating oil returns to the oil reservoir 54 at the bottom of the sealed container 42.

[0067] A centrifugal pump or viscous pump (not shown) is provided at the lower end of the crankshaft 45, and oil from the oil reservoir 54 is supplied to the compression mechanism 43 via an oil supply hole 45c for lubricating each sliding part and for sealing the suction chamber 61 and the compression chamber 62.

[0068] The second embodiment is directed to suppressing a decrease in temperature of the refrigerant gas discharged from the compression mechanism portion 43 in the above-described rotary compressor 41, and the configuration thereof will be described next. 4, in the second embodiment, a heat insulating material 59 is provided on the outside of the sealed container 42 around the motor chamber 53 (upper motor chamber 53a, lower motor chamber 53b). That is, the motor chamber 53 also serves as a discharge space for high-temperature refrigerant gas (working fluid) discharged from the compression mechanism 43, and the heat insulating material 59 is provided on the outside of the sealed container 42 in this discharge space (motor chamber 53) to suppress heat dissipation from the high-temperature refrigerant gas to the outside of the sealed container 42.

[0069] Preferably, the heat insulating material 59 is disposed so as to insulate at least the space within the sealed container from the contact portion between the compression mechanism 43 and the sealed container 42 to the discharge pipe 58. More specifically, the heat insulating material 59 is disposed so as to insulate at least the portion generally above the axial contact surface between the main bearing 46 and the cylinder 47a, i.e., the portion of the space within the sealed container (the motor chamber 53 serving as the discharge space) located on the discharge pipe 58 side. It is also preferable not to provide a heat insulating material in the portion generally below the axial contact surface between the main bearing 46 and the cylinder 47a, i.e., on the opposite side to the discharge pipe.

[0070] In this embodiment, the heat insulating material 59 is arranged to insulate the portion (the outer periphery of the sealed container 42 on the motor chamber 53 side) located above (on the discharge pipe 58 side) the main bearing 46, and no heat insulating material is provided in the portion located below the main bearing 46 (on the compression mechanism 43 side). As a result, the high-temperature refrigerant gas that flows into the motor chamber 53 via the discharge space 56 is insulated, thereby reducing heat radiation from the surface of the sealed container 42. This makes it possible to suppress a decrease in the temperature of the refrigerant gas, and to suppress a decrease in the heating capacity and space heating capacity. In addition, since no heat insulating material is provided on the compression mechanism 43 side, a decrease in compressor efficiency due to an increase in heat loss can also be suppressed.

[0071] In this second embodiment, the heat insulating material 59 made of a heat insulating cover is installed on the outer periphery of the sealed container 42, but similar to the first embodiment, a cloth-like heat insulating material may be wrapped around the outer periphery of the sealed container 2 and fixed with a string. Also, a heat insulating paint may be applied to the inner or outer periphery of the sealed container 2 to serve as a heat insulating material.

[0072] As in the first embodiment, the heat insulating material 59 may be made of phenolic resin fiber, polyethylene resin or phenolic resin foamed plastic heat insulating material, butyl rubber, or the like. When a flexible heat insulating material is used, it is preferable to wrap it around the sealed container and secure it with a string, or the like. When a non-flexible heat insulating material such as a phenolic resin foamed plastic heat insulating material is used, it is preferable to mold it and cover the sealed container 2. As the heat insulating paint, it is preferable to use a paint containing hollow ceramic particles.

[0073] In order to reduce noise generated by the compressor, a soundproof cover may be provided to cover the entire compressor in addition to providing a heat insulating material, as described in FIG. 3. In this case, the heat insulating material 59 is provided only around the motor chamber 53, and the soundproof cover is provided on the outside of the heat insulating material 59. If the material constituting the soundproof cover 33 itself has a certain degree of heat insulating function, the soundproof cover may be used as a heat insulating material as well to be used as an integrated structure. In this case, the thickness of the soundproof cover around the motor chamber 53, which becomes the discharge space, is made thicker than the thickness of the soundproof cover around the compression mechanism 43. This can improve the heat insulating property on the motor chamber 53 side, and suppress heat radiation from the refrigerant gas flowing through the motor chamber 53.

[0074] In the second embodiment, a two-cylinder rotary compressor having two compression sections has been described, but the present invention is also applicable to a rotary compressor having one compression section or three or more compression sections.

[0075] The present invention is not limited to the above-described embodiments, and includes various modified examples. For example, in the above-described embodiments, a vertical scroll compressor and a vertical rotary compressor are described as a positive displacement compressor, but the present invention is not limited to a vertical positive displacement compressor, and can be similarly applied to a horizontal positive displacement compressor. In addition, the present invention is not limited to the scroll compressor and rotary compressor described in the above-described first and second embodiments, and can be similarly applied to other types of positive displacement compressors, such as a reciprocating compressor and a rotary vane type rotary compressor.

[0076] Furthermore, in the above-mentioned embodiment, the heat insulating material is arranged to insulate the entire space inside the sealed container on the discharge pipe side from the contact portion between the compression mechanism and the sealed container, but this is not limited to insulating the entire space inside the sealed container on the discharge pipe side, and the heat insulating material may be arranged on the outer periphery of the sealed container so as to insulate a part of the space inside the sealed container on the discharge pipe side. Also, an area wider than the space inside the sealed container on the discharge pipe side may be insulated. The above-mentioned embodiment has been described in detail to easily explain the present invention, and the present invention is not necessarily limited to the embodiment having all the configurations described. Furthermore, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment. [Explanation of symbols]

[0077] 1: Scroll compressor (positive displacement compressor), 2: Closed container (case), 3: Compression mechanism, 4: motor section, 4a: stator, 4b: rotor, 5: suction pipe, 6: discharge pipe, 7: fixed scroll, 7a: base plate, 7b: fixed wrap (wrap), 7c: Fixed tooth bottom (tooth bottom), 7d: Support part, 7e: Mirror plate surface, 7f: Tooth tip, 8: rotating scroll, 8a: head plate, 8b: rotating wrap (wrap), 8c: Swivel tooth bottom (tooth bottom), 8d: Swivel boss part, 8e: Mirror plate surface, 8f: tooth tip, 8g: slewing bearing, 9: frame, 9a: main bearing, 10: crankshaft (rotating shaft), 10a: crank portion, 10b: oil hole, 10c: Lubricant suction port, 10d, 10e: Side hole, 11: discharge cover, 12: Oldham ring, 13: compression chamber, 13a: rotation inner line side compression chamber, 13b: rotation outer line side compression chamber, 14: suction port, 15: discharge port, 16: discharge space, 16a: first discharge space, 16b: second discharge space, 17: Discharge cover holder, 18: Back pressure chamber, 19: Opening, 20: Suction chamber, 21: welding, 23: auxiliary bearing, 24: upper space, 25: oil reservoir, 27: motor chamber (27a: upper motor chamber, 27b: lower motor chamber), 31: back pressure valve, 32: heat insulating material, 33: soundproof cover, 41: rotary compressor (positive displacement compressor), 42: sealed container (case), 43: Compression mechanism part, 44: motor section, 44a: stator, 44b: rotor, 45: Crankshaft (rotating shaft), 45a: first crank portion, 45b: second crank portion, 45c: oil supply hole, 46: main bearing, 47a: first cylinder, 47b: second cylinder, 48a: first roller, 48b: second roller, 49a: first vane, 49b: second vane, 50a: first spring, 50b: second spring, 51: Partition plate, 52: Sub-bearing, 53: motor chamber (53a: upper motor chamber, 53b: lower motor chamber), 54: oil reservoir, 55a: first discharge cover, 55b: second discharge cover, 56: discharge space, 57: accumulator, 57a: inlet, 57b: suction pipe, 58: discharge pipe, 59: Insulation material, 60: vane slot, 61: suction chamber, 62: compression chamber, 63: suction port, 64: outlet, 65: outflow hole, 66: through hole.

Claims

1. a sealed container; a compression mechanism portion fixed to the sealed container; and a discharge pipe provided on one end side of the sealed container for discharging the working fluid discharged from the compression mechanism portion to the outside of the sealed container, a contact portion between said compression mechanism and said sealed container, and a heat insulating material is provided to insulate the space inside said sealed container on said discharge pipe side relative to the contact portion between said compression mechanism and said sealed container;

2. 2. The positive displacement compressor according to claim 1, The positive displacement compressor is a scroll compressor, The displacement type compressor, wherein the heat insulating material is arranged so as to insulate at least a space within the sealed container from an outlet of a discharge port provided in a compression mechanism portion to the discharge pipe.

3. 2. The positive displacement compressor according to claim 1, The positive displacement compressor is a scroll compressor, and the compression mechanism portion includes a fixed scroll and a frame that supports the fixed scroll and is fixed to the sealed container, the heat insulating material is provided so as to insulate a discharge space located on the discharge pipe side from an axial contact surface between the fixed scroll and the frame, 4. A volumetric compressor comprising: a first scroll member and a second scroll frame; a second scroll member and a third scroll frame; a second scroll member and a third scroll frame;

4. 2. The positive displacement compressor according to claim 1, the positive displacement compressor is a rotary compressor, a heat insulating material disposed so as to insulate at least a space within the sealed container from the contact portion between the compression mechanism and the sealed container to the discharge pipe;

5. 2. The positive displacement compressor according to claim 1, The positive displacement compressor is a rotary compressor, and the compression mechanism unit includes a main bearing fixed to the sealed container, and a cylinder and an auxiliary bearing supported by the main bearing, the heat insulating material is provided so as to insulate a portion of the space inside the sealed container located on the discharge pipe side from an axial contact surface between the main bearing and the cylinder, 4. A volumetric compressor comprising: a first bearing and a second bearing arranged on a side of the first cylinder facing the first bearing;

6. 2. The positive displacement compressor according to claim 1, A volumetric compressor characterized in that the insulation material is composed of a body insulation material provided to cover the outer periphery of the body of the sealed container, and a lid-shaped insulation material provided to cover the discharge pipe side end of the sealed container.

7. 2. The positive displacement compressor according to claim 1, The compressor according to claim 1, wherein the heat insulating material is attached by being wrapped around an outer circumferential surface of the sealed container.

8. 2. The positive displacement compressor according to claim 1, 2. A volumetric compressor comprising: a compression mechanism and a sealed container; a sealing member that is provided with no heat insulating material on a side opposite to the discharge pipe from the contact portion between the compression mechanism and the sealed container;

9. 2. The positive displacement compressor according to claim 1, 2. A volumetric compressor, wherein the heat insulating material is formed of a heat insulating paint applied to an inner or outer peripheral surface of the sealed container.

10. 2. The positive displacement compressor according to claim 1, 4. The positive displacement compressor, further comprising a soundproof cover for covering an outer periphery of the sealed container.

11. 11. The positive displacement compressor according to claim 10, 13. A positive displacement compressor, comprising: a soundproof cover disposed outside the heat insulating material.

12. 11. The positive displacement compressor according to claim 10, 2. A positive displacement compressor, wherein the heat insulating material and the soundproof cover are integrally formed.

13. 13. The positive displacement compressor according to claim 12, The soundproof cover is made of a material having a heat insulating function, and the thickness of the soundproof cover on the discharge pipe side is made larger than the thickness of the soundproof cover on the opposite side of the discharge pipe.

14. 2. The positive displacement compressor according to claim 1, 2. A volumetric compressor, wherein the heat insulating material is made of any one of phenolic resin fiber, polyethylene resin or phenolic resin foamed plastic heat insulating material, and butyl rubber.

15. 13. The positive displacement compressor according to claim 12, 1. A volumetric compressor, wherein the soundproof cover made of a material having a heat insulating function is made of phenolic resin fiber or butyl rubber.

16. 10. The positive displacement compressor according to claim 9, 13. A positive displacement compressor, wherein the heat insulating paint is a paint containing hollow ceramic particles.

17. The compressor includes a sealed container, a compression mechanism fixed to the sealed container, a discharge pipe provided at an upper portion of the sealed container and configured to discharge a working fluid discharged from the compression mechanism to the outside of the sealed container, and an oil reservoir provided at a bottom portion of the sealed container, a heat insulating material is disposed so as to insulate a space within the sealed container on an opposite side of the compression mechanism from the oil reservoir.

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