Compressor and refrigeration cycle device

Abstract

Provided are a highly reliable compressor and refrigeration cycle device that can suppress a decrease in the fastening force fixing a rotary shaft of a rotor, and that suppress outflow of a refrigerator oil from a sealed container. A compressor according to the present disclosure has: an oil supply passage that supplies, to a compression mechanism, a refrigerator oil which a rotary shaft causes to accumulate in an oil pooling part; and an oil return pipe that is connected to the oil supply passage and discharges the refrigerator oil to a space inside a container, wherein, treating the surface of a section of a rotor or a bearing part as a collision surface, the oil return pipe is provided inclined in such an orientation that the refrigerator oil is discharged toward said collision surface. Due to this configuration, it is possible to obtain a highly reliable compressor and refrigeration cycle device that can suppress a decrease in the fastening force fixing a rotary shaft of a rotor, and can suppress outflow of a refrigerator oil from a sealed container.

Description

Compressor and refrigeration cycle device

[0001] The present disclosure relates to a compressor and a refrigeration cycle device.

[0002] A typical compressor is a hermetic compressor that includes a compression mechanism that compresses a refrigerant, a rotating shaft, and an electric motor fixed to the rotating shaft to rotate the rotating shaft and drive the compression mechanism. In such a hermetic compressor, to reduce friction in the compression mechanism, a flow path for refrigeration oil, which is a lubricating oil, is formed inside the rotating shaft. The centrifugal force generated when the electric motor rotates the rotating shaft is used to draw the refrigeration oil into the flow path and supply it to the compression mechanism through the flow path. If more refrigeration oil is drawn into the flow path than is required for the compression mechanism, the excess refrigeration oil is discharged into the hermetic compressor through an oil return pipe connected to the flow path.

[0003] A portion of the excess refrigeration oil discharged from the oil return pipe flows into the upper space of the sealed container together with the refrigerant gas discharged from the compression mechanism into the sealed container, passes through the discharge pipe provided in the sealed container, and flows out into the refrigeration cycle device outside the compressor. If excessive refrigeration oil flows into the refrigeration cycle device outside the compressor, the heat exchange rate of the refrigeration cycle device decreases, and the performance of the refrigeration cycle device deteriorates. Furthermore, if the refrigeration oil sealed in the sealed container decreases excessively, the airtightness of the compression mechanism decreases, reducing the refrigerant compression performance, or the sliding parts wear against each other, making it impossible to ensure sufficient performance and making it impossible to maintain the performance of the hermetic compressor.

[0004] To address this issue, some conventional hermetic compressors have a disk-shaped oil separator attached to the rotor to prevent refrigeration oil from leaking out of the hermetic container. This disk-shaped oil separator rotates with the rotating shaft and blows the refrigeration oil contained in the refrigerant gas discharged into the upper space of the compressor outward by centrifugal force, preventing the refrigeration oil from flowing into the discharge pipe along with the refrigerant gas (see, for example, Patent Document 1). Furthermore, some conventional hermetic compressors utilize a portion of the rotor to prevent refrigeration oil from leaking out of the hermetic container. In such compressors, the inner diameter of the shaft hole through which the rotor shaft passes is expanded from the lower end to a predetermined height, forming a recess in the rotor. The outlet of the oil return pipe is positioned radially of the rotating shaft so as to overlap the recess. Refrigeration oil discharged from the oil return pipe collides with the recess in the rotor through a gap, increasing the radius of the refrigeration oil droplets and preventing the refrigeration oil from dissolving in the refrigerant (see, for example, Figure 1 of Patent Document 2).

[0005] Japanese Utility Model Application Publication No. 7-10486 Japanese Patent Application Publication No. 2012-215158

[0006] In the compressor described above, which uses a rotor to prevent refrigeration oil from leaking from the sealed container, the oil discharged from the oil return pipe is caused to collide with a recess in the rotor, increasing the radius of the refrigeration oil droplets and preventing the refrigeration oil from turning into mist and dissolving into the refrigerant, and the refrigeration oil is returned to the bottom of the sealed container. However, this structure is formed at the expense of a portion of the shaft hole through which the rotating shaft passes, reducing the vertical length of the shaft hole and reducing the area for the rotor to secure the rotating shaft by shrink fitting or the like. This reduces the fastening force that secures the rotor to the rotating shaft, potentially reducing the reliability of the compressor.

[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a compressor and a refrigeration cycle device that can suppress a decrease in the fastening force that fixes the rotating shaft of the rotor and suppresses the leakage of refrigeration oil from the sealed container.

[0008] The compressor according to the present disclosure comprises: a container forming an outer shell and having an oil reservoir formed at the bottom inside for storing refrigeration oil; an electric motor provided inside the container; a rotating shaft provided inside the container and attached to the electric motor to rotate together with the electric motor; and a compression mechanism that compresses refrigerant as the rotating shaft rotates; the electric motor comprises a stator fixed to the inner circumference of the container and a rotor arranged inside the stator; the compression mechanism comprises a bearing that supports the rotating shaft; the rotating shaft has an oil supply passage that supplies refrigeration oil stored in the oil reservoir to the compression mechanism and an oil return pipe that is connected to the oil supply passage and discharges the refrigeration oil into the space within the container; the oil return pipe has a part of the surface of the rotor or the bearing as a collision surface, and is provided at an angle such that the refrigeration oil is discharged toward the collision surface.

[0009] In addition, a refrigeration cycle device according to the present disclosure includes the compressor according to the present disclosure, a four-way valve that switches the flow direction of the refrigerant, a condenser that performs heat exchange between the refrigerant discharged from the compressor and air, a pressure reducing device that expands the liquid refrigerant discharged from the condenser, and an evaporator that performs heat exchange between the liquid refrigerant discharged from the pressure reducing device and air.

[0010] In the compressor and refrigeration cycle device according to the present disclosure, the rotating shaft has an oil supply passage that supplies refrigeration oil stored in an oil reservoir to a compression mechanism, and an oil return pipe that is connected to the oil supply passage and discharges the refrigeration oil into the space within the container, and the oil return pipe has a part of the surface of the rotor or the bearing portion as a collision surface, and is provided at an angle in such a direction that the refrigeration oil is discharged toward the collision surface, thereby eliminating the need for a special structure on the rotor for colliding the refrigeration oil and preventing the refrigeration oil from leaking out of the sealed container. Thus, a highly reliable compressor and refrigeration cycle device can be obtained that can prevent a decrease in the fastening force that fixes the rotor rotating shaft and prevents the refrigeration oil from leaking out of the sealed container.

[0011] 1. A cross-sectional view of a compressor according to embodiment 1. A cross-sectional view of a compression mechanism of the compressor according to embodiment 1. A configuration diagram of a refrigeration cycle device according to embodiment 1. A cross-sectional view of an electric motor used in embodiment 1. A cross-sectional view of an oil return pipe and its periphery of the compressor according to embodiment 1. A cross-sectional view of an oil return pipe and its periphery of the compressor according to embodiment 2. A cross-sectional view of an oil return pipe and its periphery of the compressor according to embodiment 3. A cross-sectional view of an oil return pipe and its periphery of the compressor according to embodiment 4. A cross-sectional view of an oil return pipe and its periphery of the compressor according to embodiment 5. A cross-sectional view of an oil return pipe and its periphery of the compressor according to embodiment 6. A cross-sectional view of an oil return pipe and its periphery of the compressor according to embodiment 7. A top view of a bearing unit of the compressor according to embodiment 7. A top view of a bearing unit in a case where a convex portion is provided on the inner circumferential surface of the bearing unit in embodiment 3.

[0012] The configuration of a compressor and a refrigeration cycle device according to the present disclosure will be described below with reference to the drawings. Here, components with the same reference numerals are the same, and this applies throughout the entire specification. The configurations of the components shown throughout the specification are merely examples and are not limited to the configurations described in the specification. In particular, the shapes of the components are not limited to the shapes in the embodiments. The drawings may show simplified versions of the actual structure. Furthermore, the size of each component and the relative positions of the components in the drawings may differ from the actual size. The configurations described in each embodiment may be used in combination.

[0013] Embodiment 1. A compressor according to the present disclosure will be described using a rotary compressor as an example. FIG. 1 is a cross-sectional view of a hermetic compressor (hereinafter referred to as compressor 100) according to embodiment 1 of the present disclosure. FIG. 1 is a diagram illustrating a vertical cross section of compressor 100 installed at a position passing through the center of rotation of rotating shaft 21. FIG. 2 is a cross-sectional view of compressor 100 taken along line A-A' in FIG. 1, showing compression mechanism 20 as viewed from above. Referring to FIG. 1, the overall configuration of compressor 100, an example of a single-cylinder rotary compressor, will be described. Compressor 100 is configured by housing, within hermetic container 10, a compression mechanism 20 that compresses refrigerant gas, an electric motor 30 that drives compression mechanism 20, and a rotating shaft 21 that connects compression mechanism 20 and electric motor 30. The refrigerant gas is a working gas that operates a refrigeration cycle device. The sealed container 10 is composed of an upper container 11 and a lower container 12, with the compression mechanism 20 housed below the sealed container 10 and the electric motor 30 housed above the sealed container 10. Within the sealed container 10, the electric motor 30 is disposed above the compression mechanism 20. The compression mechanism 20 and the electric motor 30 are connected by a rotating shaft 21, which is attached to the electric motor 30 and rotates together with a rotor 31 provided in the electric motor 30. As the rotating shaft 21 rotates, the rotating shaft 21 transmits the rotational motion of the electric motor 30 to the compression mechanism 20, and the refrigerant gas is compressed in the compression mechanism 20 by the transmitted rotational force and discharged into the sealed container 10. The sealed container 10 is filled with compressed high-temperature, high-pressure refrigerant gas, and refrigerating machine oil 6, which serves as a lubricant for lubricating the compression mechanism 20, is stored in the bottom located below the sealed container 10. An oil reservoir 13 is formed at the bottom of the sealed container 10 by the storage of the refrigerating machine oil 6. The sealed container 10 constitutes an outer shell 70 of the compressor 100, and is a container in which an oil reservoir 13 in which refrigeration oil 6 is stored is formed at the bottom inside.

[0014] The rotating shaft 21 is composed of a main shaft portion 21a, an eccentric shaft portion 21b, and a counter shaft portion 21c, which are formed in this order from top to bottom in the axial direction. An electric motor 30 is fixed to the main shaft portion 21a by shrink fitting or press fitting, and a cylindrical rolling piston 22 is slidably fitted to the eccentric shaft portion 21b. The main shaft portion 21a is the portion of the rotating shaft 21 that is located above the cylinder 23 and is supported by an upper bearing 24.

[0015] The compression mechanism 20 is composed of a cylinder 23, a rolling piston 22, an upper bearing 24, a lower bearing 25, and a vane 26. Figure 2 is a cross-sectional view of the compression mechanism 20 taken along line A-A' in Figure 1 and viewed from above. The cylinder 23 has a cylindrical space, i.e., a cylinder chamber 23a, which is open at both axial ends. The cylinder chamber 23a is formed by the inner periphery of the cylinder 23 and the outer periphery of the rolling piston 22. The cylinder chamber 23a contains an eccentric shaft portion 21b of the rotary shaft 21 that performs eccentric motion within the cylinder chamber 23a, the rolling piston 22 fitted into the eccentric shaft portion 21b, and a vane 26 that partitions the cylinder chamber 23a.

[0016] The cylinder 23 is formed with a vane groove 23c, one end of which opens into the cylinder chamber 23a and the other end of which is provided with a back pressure chamber 23b. A vane 26 is housed in the vane groove 23c. The vane 26 reciprocates radially within the vane groove 23c. When attached to the vane groove 23c, the vane 26 has a substantially rectangular parallelepiped shape, with its circumferential thickness in the cylinder chamber 23a being smaller than its radial and axial lengths. A vane spring (not shown) is provided in the back pressure chamber 23b of the vane groove 23c. Normally, high-pressure refrigerant gas within the sealed container 10 flows into the back pressure chamber 23b, and the pressure difference between the refrigerant gas pressure in the back pressure chamber 23b and the refrigerant gas pressure in the cylinder chamber 23a generates a force that moves the vane 26 radially toward the center of the cylinder chamber 23a. The vane 26 is moved radially toward the center of the cylinder chamber 23a by the force due to the pressure difference between the back pressure chamber 23b and the cylinder chamber 23a and the radial pressing force of the vane spring. The force moving the vane 26 radially causes one end of the vane 26, i.e., the end on the cylinder chamber 23a side, to abut against the cylindrical outer periphery of the rolling piston 22. This separates the space formed by the inner periphery of the cylinder 23 and the outer periphery of the rolling piston 22. Even if the pressure difference between the refrigerant gas in the sealed container 10, i.e., the refrigerant gas in the back pressure chamber 23b, and the refrigerant gas in the cylinder chamber 23a, is not sufficient to press the vane 26 against the outer periphery of the rolling piston 22, the force of the vane spring can press one end of the vane 26 against the outer periphery of the rolling piston 22, so that one end of the vane 26 can always abut against the outer periphery of the rolling piston 22.

[0017] The upper bearing 24 is fitted onto the main shaft portion 21a of the rotary shaft 21 to rotatably support the main shaft portion 21a and closes one axial opening of the cylinder chamber 23a. Similarly, the lower bearing 25 is fitted onto the counter shaft portion 21c of the rotary shaft 21 to rotatably support the counter shaft portion 21c and closes the other axial opening of the cylinder chamber 23a. The cylinder 23 is provided with a suction port that draws refrigerant gas into the cylinder chamber 23a from outside the sealed container 10, and the upper bearing 24 is provided with a discharge port that discharges compressed refrigerant gas out of the cylinder chamber 23a. The upper bearing 24 is substantially inverted T-shaped in side view and includes a flat upper flat plate portion 38 and a cylindrical upper bearing portion 39 that protrudes from the upper flat plate portion 38 opposite (upward from) the cylinder 23 side and rotatably supports the rotary shaft 21. Lower bearing 25 is substantially T-shaped in side view and includes a flat lower flat plate portion 40 and a cylindrical lower bearing portion 41 that protrudes from lower flat plate portion 40 on the opposite side (downward) from cylinder 23 and rotatably supports rotating shaft 21. The bearing portion includes upper bearing portion 39 and lower bearing portion 41. Compression mechanism 20 includes upper bearing 24 on the electric motor 30 side relative to cylinder 23, and upper bearing 24 on the oil reservoir 13 side.

[0018] A discharge valve is provided in the discharge port of the upper bearing 24, and controls the discharge timing of the high-temperature, high-pressure refrigerant gas discharged through the discharge port from the cylinder 23. That is, the discharge valve closes until the refrigerant gas compressed in the cylinder chamber 23a of the cylinder 23 reaches a predetermined pressure, and opens when the pressure reaches or exceeds the predetermined pressure, thereby discharging the high-temperature, high-pressure refrigerant gas out of the cylinder chamber 23a.

[0019] Because the refrigerant gas is repeatedly sucked, compressed, and discharged within the cylinder chamber 23a, the refrigerant gas discharged from the discharge port is discharged intermittently, resulting in noise such as pulsating sounds. To reduce this, a discharge muffler 27 is attached to the outside of the upper bearing 24, i.e., on the motor 30 side, so as to cover the upper bearing 24. The discharge muffler 27 has a discharge hole that connects the space formed by the discharge muffler 27 and the upper bearing 24 with the inside of the sealed container 10. The refrigerant gas discharged from the cylinder 23 through the discharge port is first discharged into the space formed by the discharge muffler 27 and the upper bearing 24, and then discharged from the discharge hole into the sealed container 10.

[0020] A suction muffler 101 is provided next to the sealed container 10 to prevent liquid refrigerant from being directly drawn into the cylinder chamber 23a of the cylinder 23. Generally, a mixture of low-pressure refrigerant gas and liquid refrigerant is sent to the compressor 100 from an external circuit to which the compressor 100 is connected. If the liquid refrigerant flows into the cylinder 23 and is compressed by the compression mechanism 20, the compression mechanism 20 will malfunction. Therefore, the suction muffler 101 separates the liquid refrigerant from the refrigerant gas and sends only the refrigerant gas to the cylinder chamber 23a. The suction muffler 101 is connected to the suction port of the cylinder 23 by a suction connecting pipe, and the low-pressure refrigerant gas sent from the suction muffler 101 is drawn into the cylinder chamber 23a via the suction connecting pipe.

[0021] The compression mechanism 20 is configured as described above. Rotation of the rotary shaft 21 rotates the eccentric shaft portion 21b of the rotary shaft 21 within the cylinder chamber 23a of the cylinder 23. The volume of the working chamber, defined by the inner periphery of the cylinder chamber 23a, the outer periphery of the rolling piston 22 fitted to the eccentric shaft portion 21b, and the vane 26, increases and decreases as the rotary shaft 21 rotates. First, the working chamber communicates with the suction port, and low-pressure refrigerant gas is drawn in. Next, the suction port is closed, and the volume of the working chamber decreases, compressing the refrigerant gas within the working chamber. Finally, the working chamber communicates with the discharge port. After the refrigerant gas within the working chamber reaches a predetermined pressure, a discharge valve provided in the discharge port opens, and the compressed, high-pressure, high-temperature refrigerant gas is discharged from the working chamber, i.e., the cylinder chamber 23a. The high-pressure, high-temperature refrigerant gas discharged from the cylinder chamber 23a into the sealed container 10 via the discharge muffler 27 passes through the motor 30, rises inside the sealed container 10, and is discharged to the outside of the sealed container 10 from a discharge pipe 102 provided at the top of the sealed container 10. A refrigeration circuit through which the refrigerant flows is configured outside the sealed container 10, and the discharged refrigerant circulates through the refrigeration circuit and returns to the suction muffler 101.

[0022] 3 is a schematic diagram of a refrigeration cycle apparatus such as an air conditioner to which a compressor 100 is connected. The refrigeration cycle apparatus 200 includes a suction muffler 101 of the compressor 100 connected to the suction side of the compressor 100, a four-way switching valve 103 connected to the discharge side of the compressor 100 for switching the flow of refrigerant from the compressor 100, an outdoor heat exchanger 104, a pressure reducer 105 such as an electric expansion device, and an indoor heat exchanger 106, which are connected in sequence via piping to form a refrigeration circuit. In general, in a refrigeration air conditioner, the indoor heat exchanger 106 is installed in an indoor device, and the remaining compressor 100, the four-way switching valve 103, the outdoor heat exchanger 104, and the pressure reducer 105 are installed in an outdoor device.

[0023] For example, in heating operation of the air conditioner, four-way switching valve 103 is connected to the solid line side in Figure 3. High-temperature, high-pressure refrigerant compressed by compressor 100 flows to indoor heat exchanger 106, condenses, and liquefies, and is then throttled by pressure reducer 105 to become a two-phase refrigerant with low temperature and low pressure. The refrigerant then flows to outdoor heat exchanger 104, evaporates, and gasifies before returning to compressor 100 through four-way switching valve 103. In other words, the refrigerant circulates as shown by the solid arrows in Figure 3. Through this circulation, the refrigerant exchanges heat with outside air in outdoor heat exchanger 104, which serves as an evaporator, and the refrigerant sent to outdoor heat exchanger 104 absorbs heat. The refrigerant that has absorbed heat is then sent to indoor heat exchanger 106, which serves as a condenser, where it exchanges heat with indoor air and warms the indoor air.

[0024] In cooling operation, the four-way switching valve 103 is connected to the dashed line side in Figure 3. The high-temperature, high-pressure refrigerant compressed by the compressor 100 flows to the outdoor heat exchanger 104, where it condenses and liquefies. It is then throttled by the pressure reducer 105, becoming a two-phase refrigerant with low temperature and low pressure. The refrigerant then flows to the indoor heat exchanger 106, where it evaporates and gasifies, and the four-way switching valve 103 returns to the compressor 100. That is, when the operation mode switches from heating to cooling, the indoor heat exchanger 106 changes from a condenser to an evaporator, and the outdoor heat exchanger 104 changes from an evaporator to a condenser. Thus, the refrigerant circulates as shown by the dashed arrows in Figure 3. Through this circulation, the indoor heat exchanger 106, which functions as an evaporator, exchanges heat with the indoor air, absorbing heat from the indoor air and cooling it. The refrigerant that has absorbed heat is then sent to the outdoor heat exchanger 104, which functions as a condenser, where it exchanges heat with the outdoor air and releases heat to the outdoor air.

[0025] Examples of the refrigerant include a fluorine-based refrigerant or a hydrocarbon-based refrigerant with a low global warming potential (GWP). Examples of the refrigerant include a single refrigerant such as R1234yf, R1234ze, R32, or R290, a mixture of two or more of these, or a mixture of any of these with other refrigerants. Examples of the refrigerant include a mixed refrigerant containing R1132(E) or a mixed refrigerant containing R1123. Examples of the refrigerant include a mixed refrigerant containing R516A, R410A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, and R459A.

[0026] Next, a description will be given of the electric motor 30 that transmits rotational force to the compression mechanism 20. Fig. 4 is a cross-sectional view of the electric motor 30 taken along line B-B' in Fig. 1 and viewed from the top. The electric motor 30 includes a substantially cylindrical stator 42 fixed to the inner periphery of the sealed container 10, and a substantially columnar rotor 31 disposed inside the stator 42.

[0027] The rotor 31 is composed of a rotor core 32 formed by laminating core sheets punched from thin electromagnetic steel plates. Rotor configurations include those that use permanent magnets, as in brushless DC motors, and those that use secondary windings, as in induction motors. For example, in the case of a brushless DC motor as shown in FIG. 4 , magnet insertion holes 33 are provided axially in the rotor core 32, and permanent magnets 34, such as ferrite magnets or rare-earth magnets, are inserted into the magnet insertion holes. The permanent magnets 34 form magnetic poles on the rotor 31. The rotor 31 is rotated by the interaction of the magnetic flux generated by the magnetic poles on the rotor 31 and the magnetic flux generated by the stator windings of the stator 42. In the case of an induction motor (not shown), a secondary winding is provided on the rotor core 32 instead of a permanent magnet, and the stator windings of the stator 42 induce magnetic flux in the secondary winding on the rotor side, generating a rotational force and rotating the rotor 31.

[0028] A shaft hole 46 through which the rotating shaft 21 passes is provided in the center of the rotor core 32, and a main shaft portion 21a of the rotating shaft 21 is fastened by shrink fitting or the like. This transmits the rotational motion of the rotor 31 to the rotating shaft 21. Air holes 35 are provided around the shaft hole 46, and high-pressure, high-temperature gaseous refrigerant compressed by the compression mechanism 20 below the electric motor 30 passes through the air holes 35. The refrigerant compressed by the compression mechanism 20 also passes through the air gap between the rotor 31 and the stator 42 and the gaps in the stator windings in addition to the air holes 35. Balance weights 36a, 36b are fixed to the top and bottom of the rotor 31 to balance the entire rotating system in the compressor 100.

[0029] The rotating shaft 21 has an oil supply passage 47 formed therein, which opens to an end 37 of the countershaft portion 21c of the rotating shaft 21. The end 37 constitutes one end of the rotating shaft 21 and corresponds to the lower end of the rotating shaft 21. The end 37 faces downward, i.e., toward the bottom of the sealed container 10. The end 37 is located inside the oil reservoir 13 stored in the bottom of the sealed container 10. One end of the oil supply passage 47 opens to the end 37 and opens into the oil reservoir 13 stored in the bottom of the sealed container 10. The oil supply passage 47 extends along the rotation center of the rotating shaft 21. The oil supply passage 47 is formed in the lower part of the rotating shaft 21, and is formed inside the countershaft portion 21c, the eccentric shaft portion 21b, and a part of the main shaft portion 21a. The rotating shaft 21 also has a first oil supply port 43 and a second oil supply port 44 formed therein. The first oil fill port 43 and the second oil fill port 44 serve as flow paths that supply the refrigeration oil 6 sucked into the oil supply passage 47 to the sliding parts of the compression mechanism 20. One end of each of the first oil fill port 43 and the second oil fill port 44 is connected to the oil supply passage 47. The other end of each of the first oil fill port 43 and the second oil fill port 44 opens at a position on the outer circumferential surface 67 of the rotating shaft 21 that faces the compression mechanism 20. The oil supply passage 47 supplies the refrigeration oil 6 stored in the oil reservoir 13 to the compression mechanism 20. In the first embodiment, the other end of the first oil fill port 43 opens at a position that faces the upper bearing 24 of the compression mechanism 20. The other end of the second oil fill port 44 opens at a position that faces the lower bearing 25 of the compression mechanism 20.

[0030] The centrifugal pump 45 is provided inside the oil supply passage 47 of the rotating shaft 21. The centrifugal pump 45 is formed by twisting a plate-like member. The centrifugal pump 45 is a fluid machine that uses centrifugal force generated by the rotational motion of the rotating shaft 21 to suck up refrigerating machine oil 6, which forms an oil reservoir 13 stored at the bottom of the sealed container 10. The refrigerating machine oil 6 sucked up into the oil supply passage 47 by the centrifugal pump 45 is supplied to the sliding portion of the compression mechanism 20. Specifically, a portion of the refrigerating machine oil 6 sucked up into the oil supply passage 47 is supplied through the first oil supply port 43 to the sliding portion between the upper bearing 24 of the compression mechanism 20 and the rotating shaft 21. Furthermore, a portion of the refrigerating machine oil 6 sucked up into the oil supply passage 47 is supplied through the second oil supply port 44 to the sliding portion between the lower bearing 25 of the compression mechanism 20 and the rotating shaft 21. For example, mineral oil-based, alkylbenzene-based, polyalkylene glycol-based, polyvinyl ether-based, and polyol ester-based refrigerating oils are used as the refrigerating oil 6. Refrigerating oil 6 that is sucked up into the oil supply passage 47 in excess of that required for the sliding parts is discharged into the space within the sealed container 10 via the oil return pipe 50.

[0031] In the compressor 100 configured as described above, the configuration of the oil return pipe 50 that discharges the refrigeration oil 6 into the space within the sealed container 10, and the rotor 31 and upper bearing 24 with which the refrigeration oil 6 discharged from the oil return pipe 50 collides will be described below.

[0032] <Configuration of Oil Return Pipe 50> The rotating shaft 21 is formed with an oil return pipe 50 downstream of the first oil supply port 43 and the second oil supply port 44 with respect to the flow of the refrigeration oil 6. The oil return pipe 50 is structured to discharge the refrigeration oil 6 in the oil supply passage 47 into the space inside the sealed container 10 and return it to the oil reservoir 13 when more refrigeration oil 6 than is required for the sliding parts is sucked up into the oil supply passage 47. The oil return pipe 50 extends from the surface (outer peripheral surface 67) of the rotating shaft 21 toward the central axis, connects to the oil supply passage 47, and connects to the space 48 between the rotor 31 and the upper bearing 24, which is the space inside the sealed container 10. The oil return pipe 50 connects the oil supply passage 47 and the space 48 between the rotor 31 and the upper bearing 24.

[0033] The oil return pipe 50 has an upstream end that opens midway through the oil supply passage 47 with respect to the flow of the refrigeration oil 6 in the oil supply passage 47, forming a first opening 51. The oil return pipe 50 has a downstream end that opens into the space 48 between the rotor 31 and the upper bearing 24 with respect to the flow of the refrigeration oil 6, forming a second opening 52. The oil return pipe 50 opens between the electric motor 30 and the compression mechanism 20 at a position that does not overlap with the rotor 31 in the radial direction of the rotating shaft 21. The second opening 52, which is the outlet of the oil return pipe 50, is located below the vent 35, which is formed in the rotor 31 and communicates with the upper space of the compressor 100 to allow refrigerant gas to pass through. The first opening 51 and the second opening 52 of the oil return pipe 50 open above the first oil fill port 43 and the second oil fill port 44 in the oil supply passage 47. Furthermore, the first opening 51 and the second opening 52 of the oil return pipe 50 are located downstream of the first oil supply port 43 and the second oil supply port 44 in the oil supply passage 47 with respect to the flow of the refrigeration oil 6 .

[0034] The oil return pipe 50 is provided below the rotor 31 (toward the compression mechanism 20). The oil return pipe 50 is provided at a position that does not overlap with the rotor 31 in the radial direction of the rotating shaft 21. The oil return pipe 50 is provided on the rotating shaft 21 at an angle such that the refrigeration oil 6 discharged from the second opening 52 collides with a part of the rotor 31 or a part of the upper bearing 24. In this specification, the surfaces of the rotor 31 and the upper bearing 24 against which the refrigeration oil 6 discharged from the oil return pipe 50 collides are referred to as collision surfaces. The second opening 52 is spaced from the collision surface 53 and opens to the outer peripheral surface 67 of the rotating shaft 21 between the electric motor 30 and the compression mechanism 20. The oil return pipe 50 is provided on the rotating shaft 21 at an angle such that the refrigeration oil 6 is discharged toward the collision surface 53. The refrigeration oil 6 that has collided with the collision surface 53 becomes larger in droplet size than when no collision occurs, and is more likely to move downward within the sealed container 10 and to the bottom of the sealed container 10. In this way, the refrigeration oil 6 is prevented from moving to the discharge pipe 102 above the sealed container 10, and the refrigeration oil 6 is prevented from flowing into the refrigeration cycle device 200 outside the compressor 100.

[0035] FIG. 5 is a cross-sectional view showing the oil return pipe 50 and its surroundings in a compressor 100 according to this embodiment, in which the oil return pipe 50 faces the rotor 31. Using FIG. 5 , a case in which refrigeration oil 6 discharged from the oil return pipe 50 collides with the surface of the rotor 31 will be described. The rotor 31 has a fixed surface 54 to which the rotating shaft 21 is fixed by shrink fitting or the like, and a lower surface 55 extending radially outward from the lower end of the fixed surface 54. The lower surface 55 is a circular surface when viewed from above the rotor 31, and has an opening on the inside for passing the rotating shaft 21 through. The fixed surface 54 is a connecting portion of the rotor 31 that connects to the rotating shaft 21. The lower surface 55 faces the space 48 between the rotor 31 and the upper bearing 24 within the sealed container 10. In FIG. 5 , the second opening 52 of the oil return pipe 50 is formed on the outer peripheral surface 67 of the rotating shaft 21 between the rotor 31 and the upper bearing 24, i.e., below the rotor 31 and above the upper bearing 24. The second opening 52 is located below and near the lower surface 55 of the rotor 31. The second opening 52 is located above (toward the lower surface 55) the first opening 51. The second opening 52 opens into the space 48 between the rotor 31 and the upper bearing 24. The oil return pipe 50 is formed on the rotating shaft 21 so that the refrigeration oil 6 blown out from the second opening 52 is blown out toward the lower surface 55. The oil return pipe 50 is inclined relative to the oil flow so that the downstream side is located higher than the upstream side rather than being horizontal. The oil return pipe 50 is provided on the rotating shaft 21 so that an extension of the central axis intersects with the lower surface 55.

[0036] With this configuration, during operation of the compressor 100 of this embodiment, the rotation of the rotor 31 rotates the rotating shaft 21, and the centrifugal pump 45 pumps the refrigeration oil 6 forming the oil reservoir 13 into the oil supply passage 47. Of the refrigeration oil 6 pumped into the oil supply passage 47, any surplus refrigeration oil 6 that is not supplied to the sliding parts of the compression mechanism 20 passes through the oil supply passage 47, passes through the oil return pipe 50, and is blown out into the space 48 between the rotor 31 and the upper bearing 24. The refrigeration oil 6 that passes through the oil return pipe 50 is blown out toward the underside 55 of the rotor 31 from a second opening at the downstream end of the oil return pipe 50. In the configuration of the compressor 100 shown in FIG. 5 , the underside 55 corresponds to the collision surface against which the refrigeration oil 6 impinges. The refrigeration oil 6 that impinges on the underside 55 turns into droplets upon impact, preventing dissolution into the refrigerant gas filling the space 48. The refrigerating machine oil 6 that has been turned into droplets moves downward within the sealed container 10 and is re-collected in the oil reservoir 13. With this configuration, it is possible to prevent the refrigerating machine oil 6 discharged from the oil return pipe 50 from passing through the discharge pipe 102 located above the rotor 31 and flowing into the refrigeration cycle device outside the compressor 100.

[0037] With this configuration, when the compressor 100 is operating, surplus refrigeration oil 6 that has been sucked into the oil supply passage 47 and has not been supplied to the sliding parts of the compression mechanism 20 is discharged from the second opening of the oil return pipe 50 toward the underside 55 of the rotor 31 so as to avoid the air holes 35. Therefore, the refrigeration oil 6 discharged from the oil return pipe 50 is prevented from entering the air holes 35, the movement of the refrigeration oil 6 to the discharge pipe 102 above the sealed container 10 is prevented, and the refrigeration oil 6 can be prevented from flowing into the refrigeration cycle device 200 outside the compressor 100.

[0038] Second Embodiment Next, a compressor and a refrigeration cycle device according to a second embodiment will be described with reference to Fig. 6. In the second embodiment, items that are not particularly described are the same as those in the first embodiment, and the same functions and configurations as those in the first embodiment will be described using the same reference numerals.

[0039] FIG. 6 is a cross-sectional view showing the oil return pipe 50 and its surroundings in a compressor 110 according to this embodiment, in which the oil return pipe 50 faces the upper bearing 24. Using FIG. 6 , a case in which refrigeration oil 6 discharged from the oil return pipe 50 collides with the surface of the upper bearing 24 will be described. Below, differences between the configuration in FIG. 6 and the configuration in FIG. 5 will be mainly described. The upper bearing 24 has a flat upper plate portion 38 that covers the cylinder 23 and forms the cylinder chamber 23a together with the cylinder 23 and the lower bearing 25, and a cylindrical upper bearing portion 39 that protrudes from the upper plate portion 38 toward the opposite side from the cylinder 23 and rotatably supports the rotating shaft 21. The upper bearing portion 39 has a sliding surface 58 on its inner periphery that rotatably supports the rotating shaft 21. The sliding surface 58 is a connection portion where the upper bearing portion 39 contacts the rotating shaft 21. The upper bearing portion 39 has an upper end surface 59 at its upper end 49, which is a surface that extends radially outward from the sliding surface 58 of the rotating shaft 21. The upper end surface 59 faces the space 48 between the rotor 31 and the upper bearing 24 within the sealed container 10. In FIG. 6 , the second opening 52 of the oil return pipe 50 is formed above the upper end surface 59 of the rotating shaft 21. The second opening 52 is formed on the outer peripheral surface 67 of the rotating shaft 21 near the upper end surface 59. The first opening 51 of the oil return pipe 50 is located above the upper end surface 59 and above the second opening 52, which is the downstream end. The oil return pipe 50 is formed on the rotating shaft 21 so that the refrigeration oil 6 blown out from the second opening 52 is blown out toward the upper end surface 59. The oil return pipe 50 is inclined relative to the oil flow so that the upstream side is higher than the downstream side. 6, the first opening 51 is upstream and the second opening 52 is downstream. The oil return pipe 50 is provided on the rotating shaft 21 such that an extension of the central axis intersects with the upper end surface 59.

[0040] With this configuration, during operation of the compressor 110 according to the second embodiment, the rotation of the rotor 31 rotates the rotating shaft 21, and the centrifugal pump 45 pumps the refrigeration oil 6 forming the oil reservoir 13 into the oil supply passage 47. Of the refrigeration oil 6 pumped into the oil supply passage 47, any excess refrigeration oil 6 that is not supplied to the sliding parts of the compression mechanism 20 enters the oil return pipe 50 from the oil supply passage 47 and is discharged through the oil return pipe 50 into the space 48 within the sealed container 10. The refrigeration oil 6 that has passed through the oil return pipe 50 is blown out toward the upper end surface 59 of the upper bearing 24 from a second opening 52, which is the downstream end of the oil return pipe 50. In the configuration of the compressor 110 shown in FIG. 6 , the upper end surface 59 corresponds to the collision surface against which the refrigeration oil 6 impinges. The refrigeration oil 6 that impinges on the upper end surface 59 turns into droplets upon impact, suppressing dissolution into the refrigerant gas filled in the sealed container 10. Furthermore, larger droplets of refrigerating oil 6 tend to flow downward and are more likely to be collected in the oil reservoir 13. With the above configuration, it is possible to prevent refrigerating oil 6 discharged from the oil return pipe 50 from passing through the discharge pipe 102 and leaking into the refrigeration cycle device outside the compressor 110. As described above, the compressor 110 according to the second embodiment does not require any special structure for causing refrigerating oil to collide with the rotating shaft 21 other than the provision of the oil return pipe 50, and therefore it is possible to prevent refrigerating oil from leaking out of the sealed container 10 without reducing the fastening force that secures the rotating shaft of the rotor. Therefore, it is possible to obtain a highly reliable compressor and refrigeration cycle device that can prevent a reduction in the fastening force that secures the rotating shaft of the rotor and that prevents refrigerating oil from leaking out of the sealed container.

[0041] Third Embodiment Next, a compressor and a refrigeration cycle device according to a third embodiment will be described with reference to Fig. 7. In the third embodiment, items that are not particularly described are the same as those in the second embodiment, and the same functions and configurations as those in the second embodiment will be described using the same reference numerals.

[0042] Fig. 7 is a cross-sectional view showing the oil return pipe 50 and its surroundings provided in the compressor 120 according to embodiment 3. In the configuration of the compressor 120 shown in Fig. 7, the oil return pipe 50 faces the upper bearing 24 side.

[0043] In the compressor 120 according to the third embodiment, the upper bearing portion 39 has an inner peripheral lower surface 80 above the sliding surface 58, which is inclined so as to widen radially outward from the rotating shaft 21, and an inner peripheral surface 60-1 inclined so as to widen upward from the outer periphery of the inner peripheral lower surface 80. The inner peripheral lower surface 80 connects the upper end of the sliding surface 58 to the inner peripheral surface 60-1 and has an annular shape when the upper bearing portion 39 is viewed from above. The inner peripheral surface 60-1 is formed from the inner peripheral lower surface 80 to the upper end surface 59 of the upper bearing portion 39. A gap 61-1 is formed between the inner peripheral surface 60 and the rotating shaft 21. The gap 61-1 is open to the space within the sealed container 10 and constitutes part of the space 48 between the rotor 31 and the upper bearing 24. The inner peripheral surface 60-1 faces the space 48 between the rotor 31 and the upper bearing 24. The gap 61-1 is a space (gap) between the inner circumferential surface 60-1 and the rotor 21 in the radial direction of the rotary shaft 21, and the width in the radial direction increases toward the top.

[0044] The oil return pipe 50 has a second opening 52 at a position facing the inner circumferential surface 60-1 of the upper bearing 39. The second opening 52 is provided on the rotating shaft 21 at a position overlapping the inner circumferential surface 60-1 in the radial direction of the rotating shaft 21. The oil return pipe 50 is oriented horizontally or tilted so that the upstream side is positioned lower than the downstream side with respect to the oil flow. Refrigerant oil 6 that passes through the oil return pipe 50 is blown out toward the inner circumferential surface 60-1 from the second opening 52 at its downstream end. In FIG. 7 , the inner circumferential surface 60-1 of the upper bearing 24 corresponds to the collision surface against which the refrigerant oil 6 collides. Some of the refrigerant oil 6 that collides with the inner circumferential surface 60-1 also collides with the outer circumferential surface 67 of the rotating shaft 21, colliding multiple times within the gap 61-1. This collision breaks the refrigerant oil 6 into droplets, which inhibits dissolution into the refrigerant gas filled in the sealed container 10. Therefore, in addition to the effects of the second embodiment, the compressor 120 according to the third embodiment can increase the area and number of times that the refrigerating oil 6 is collided, thereby improving the ability to turn the refrigerating oil into droplets.

[0045] Fourth Embodiment Next, a compressor and a refrigeration cycle device according to a fourth embodiment will be described with reference to Fig. 8. In this embodiment, items that are not particularly described are the same as those in the third embodiment, and the same functions and configurations as those in the third embodiment will be described using the same reference numerals.

[0046] Fig. 8 is a cross-sectional view showing an oil return pipe 50 and its surroundings provided in a compressor 130 according to embodiment 4. In the configuration of the compressor 130 shown in Fig. 8, the oil return pipe 50 faces the upper bearing 24 side.

[0047] In the compressor 130 according to the fourth embodiment, the upper bearing portion 39 has a cylindrical inner circumferential surface 60-2 that extends vertically upward from the outer periphery of the inner circumferential lower surface 80. In FIG. 8 , the inner circumferential surface 60-2 is parallel to the outer circumferential surface 67 of the rotating shaft 21, and a gap 60-2 is formed between the inner circumferential surface 66 and the rotating shaft 21. The gap 60-2 is open to the space within the sealed container 10 and constitutes part of the space 48 between the rotor 31 and the upper bearing 24. The distance between the inner circumferential surface 60-2 and the outer circumferential surface 67 in the radial direction of the rotating shaft 21 is equal in both the circumferential direction of the rotating shaft 21 and the up-down direction in the radial direction of the rotating shaft 21. The oil return pipe 50 has a second opening 52 at a position facing the inner circumferential surface 60-2 of the upper bearing portion 39. In FIG. 8 , the inner circumferential surface 60-2 of the upper bearing 24 corresponds to the collision surface against which the refrigeration oil 6 discharged from the oil return pipe 50 collides. In the configuration of the fourth embodiment, the width of the gap 61-2 in the vertical direction in the radial direction of the rotating shaft 21 is constant, and no widened portion whose width in the radial direction of the rotating shaft 21 is larger than the surrounding area is formed on the sliding surface 58 side of the second opening 52. Therefore, in the compressor 103 according to the fourth embodiment, compared to when the gap 61-3 has a widened portion on the sliding surface 58 side of the second opening 52, the refrigeration oil 6 that collides with the collision surface is prevented from accumulating on the sliding surface 58 side of the second opening 52 and is more likely to flow into the space 48. Therefore, in the compressor 130 according to the fourth embodiment, in addition to the effects of the third embodiment, the collision surface can be easily formed by processing the bearing portion.

[0048] Embodiment 5 Next, a compressor and a refrigeration cycle device according to embodiment 5 will be described. In this embodiment, items that are not particularly described are the same as those in embodiment 2, and the same functions and configurations as those in embodiment 2 will be described using the same reference numerals.

[0049] Fig. 9 is a cross-sectional view showing an oil return pipe 50 and its surroundings provided in a compressor 140 according to embodiment 5. In the configuration of compressor 140 shown in Fig. 9, oil return pipe 50 is directed toward upper bearing 24.

[0050] In the compressor 140 according to the fifth embodiment, a recess is provided in the circumferential direction on the outer peripheral surface 67 of the rotating shaft 21, and a rotating shaft recess 62 recessed inward is formed in the outer peripheral surface 67. The rotating shaft recess 62 is wider than the second opening 52 of the oil return pipe 50, and the second opening 52 is formed within the rotating shaft recess 62. The upper bearing portion 39 has a cylindrical inner peripheral surface 60-3 above the sliding surface 58 that extends upward and is continuous with the sliding surface 58. The inner peripheral surface 60-3 is a surface that faces the rotating shaft recess 62. The oil return pipe 50 has the second opening 52 at a position facing the inner peripheral surface 60-3. In FIG. 9 , the inner peripheral surface 60-3 of the upper bearing 24 corresponds to the collision surface against which the refrigeration oil 6 discharged from the oil return pipe 50 collides. 9, the rotating shaft recess 62 and the inner circumferential surface 60-3 are positioned so as to overlap in the circumferential direction of the rotating shaft 21 and also overlap in the vertical direction in the radial direction of the rotating shaft 21. The inner circumferential surface 60-3 is parallel to the outer circumferential surface 67 of the rotating shaft 21, and a gap 61-3 is formed between the inner circumferential surface 60-3 and the rotating shaft recess 62. The upper end 65 of the rotating shaft recess 62 is located above the upper end of the inner circumferential surface 60-3, i.e., above the upper end surface 59 of the upper bearing portion 39. With this structure, the gap 61-3 is open to the space within the sealed container 10 and constitutes part of the space 48 between the rotor 31 and the upper bearing 24.

[0051] In the configuration of embodiment 5, the width of gap 61-3 in the radial direction of rotating shaft 21 is constant, and gap 61-3 does not have an expanded portion that is wider in the radial direction of rotating shaft 21 than the surrounding area on the sliding surface 58 side of second opening 52. Therefore, in compressor 140 according to embodiment 5, compared to when gap 61-3 has an expanded portion on the sliding surface 58 side of second opening 52, refrigerating machine oil 6 that has impacted the impact surface is less likely to stagnate on the sliding surface 58 side of second opening 52 and more likely to flow into space 48. Therefore, compressor 140 according to embodiment 5 has the effect of embodiment 3, and in addition, the impact surface can be easily formed by machining rotating shaft 21.

[0052] Sixth Embodiment Next, a compressor and a refrigeration cycle device according to a sixth embodiment will be described with reference to Fig. 10. In the sixth embodiment, items that are not particularly described are the same as those in the fifth embodiment, and the same functions and configurations as those in the fifth embodiment will be described using the same reference numerals.

[0053] Fig. 10 is a cross-sectional view showing an oil return pipe 50 and its surroundings provided in a compressor 150 according to embodiment 6. In the configuration of compressor 150 shown in Fig. 10, oil return pipe 50 is directed toward upper bearing 24.

[0054] In a compressor 150 according to the sixth embodiment, a recess is provided in the outer peripheral surface 67 of the rotating shaft 21, and a rotating shaft recess 62 recessed inward is formed in the outer peripheral surface 67. The rotating shaft recess 62 is wider than the second opening 52 of the oil return pipe 50, and the second opening 52 is formed within the rotating shaft recess 62. Also, in the sixth embodiment, as in the third embodiment, the upper bearing portion 39 has an inner peripheral lower surface 80 extending radially outward from the rotating shaft 21 above the sliding surface 58, and an inner peripheral surface 60-1 that is inclined so as to extend upward radially outward from the outer periphery of the inner peripheral lower surface 80. The rotating shaft recess 62 and the inner peripheral surface 60-1 overlap in the circumferential direction of the rotating shaft 21 and are positioned so as to overlap vertically in the radial direction of the rotating shaft 21. A gap 61-4 is formed between the rotating shaft recess 62 and the inner peripheral surface 60-1. An upper end 65 of the rotating shaft recess 62 is located above the upper end of the inner circumferential surface 60-1, i.e., above the upper end surface 59 of the upper bearing portion 39. With this structure, the gap 61-4 is open to the space within the sealed container 10 and constitutes part of the space 48 between the rotor 31 and the upper bearing 24. The gap 61-4 is a space (gap) between the inner circumferential surface 60-1 and the rotating shaft recess 62 in the radial direction of the rotating shaft 21, and the width of the space increases as it goes upward.

[0055] The oil return pipe 50 is oriented horizontally or inclined so that the upstream side is positioned lower than the downstream side with respect to the oil flow. The oil return pipe 50 has a second opening 52 at a position facing the inner circumferential surface 60-1 of the upper bearing portion 39. In FIG. 10 , the second opening 52 is formed on the rotating shaft 21 at a position that overlaps with the inner circumferential surface 60-1 in the radial direction of the rotating shaft 21 and overlaps with the inner circumferential surface 60-1 in the vertical direction of the radial direction of the rotating shaft 21. The refrigeration oil 6 that has passed through the oil return pipe 50 is blown out from the second opening 52 toward the inner circumferential surface 60-1. In FIG. 10 , the inner circumferential surface 60-1 of the upper bearing 24 corresponds to the collision surface with which the refrigeration oil 6 discharged from the oil return pipe 50 collides. Since the upper end 65 of the rotating shaft recess 62 is located above the upper end surface 59 of the upper bearing portion 39, the refrigeration oil 6 that collides with the inner circumferential surface 60-1 passes through the rotating shaft recess 62 and is easily released into the space 48. Therefore, in the compressor 150 according to the sixth embodiment, in addition to the effect of the second embodiment, the refrigeration oil 6 that collides with the outer circumferential surface 67 is easily moved into the space 48.

[0056] In the compressor 150 according to the sixth embodiment, the rotating shaft recess 62 and the inner circumferential surface 60-1 are overlapped in the radial direction of the rotating shaft 21 to form a gap 61-4 for turning the refrigerating machine oil 6 into droplets. Therefore, in addition to the effects of the fifth embodiment, it is possible to suppress a reduction in the diameter of the rotating shaft 21 due to the provision of the rotating shaft recess 62, and to suppress a decrease in the strength of the rotating shaft. Note that in the sixth embodiment, the structure of the inner circumferential surface is configured similarly to the inner circumferential surface 60-1 of the third embodiment, but this is not limited thereto, and the inner circumferential surface may adopt the inner circumferential surface 60-2 of the fourth embodiment. In this case, the upper bearing portion 39 is easier to manufacture than when the inner circumferential surface 60-1 is adopted.

[0057] Embodiment 7 Next, a compressor and a refrigeration cycle device according to Embodiment 7 will be described. In Embodiment 7, items that are not particularly described are the same as those in Embodiment 2, and the same functions and configurations as those in Embodiment 2 will be described using the same reference numerals.

[0058] Fig. 11 is a cross-sectional view showing an oil return pipe 50 and its surroundings provided in a compressor 160 according to embodiment 7. In the configuration of compressor 160 shown in Fig. 11, oil return pipe 50 faces toward upper bearing 24. Fig. 12 is a top view of an upper end surface 59 of annular upper bearing portion 39.

[0059] As shown in FIG. 12 , in a compressor 160 according to the seventh embodiment, a plurality of protrusions 68 are provided on the upper end surface 59 of the annular upper bearing portion 39 along the circumferential direction of the rotating shaft 21. Providing the protrusions 68 on the upper end surface 59 of the upper bearing portion 39 increases the surface area of ​​the upper end surface 59, thereby increasing the amount of refrigeration oil 6 discharged from the oil return pipe 50 that comes into contact with the upper bearing portion 39 as it flows along the upper end surface 59 relative to the upper bearing portion 39. This configuration results in larger droplets of refrigeration oil 6 upon impact than when the upper end surface 59 is flat. Therefore, in the compressor 160 according to the seventh embodiment, dissolution of the refrigeration oil 6 into the refrigerant is suppressed more than in the second embodiment. Larger droplets of refrigeration oil 6 tend to flow downward, facilitating recovery of the refrigeration oil in the oil reservoir 13. This configuration allows the compressor 160 according to the seventh embodiment to return the refrigeration oil 6 to the oil reservoir 13 more efficiently than in the second embodiment.

[0060] During operation of the compressor 160, refrigeration oil 6 drawn into the oil supply passage 47 and surplus refrigeration oil that is not supplied to the sliding parts of the compression mechanism 20 is discharged from the second opening of the oil return pipe 50 toward the convex portion 68 provided on the upper end surface 59 of the upper bearing 24. When the refrigeration oil 6 discharged from the oil return pipe 50 collides with the convex portion 68 of the upper bearing 24, the refrigeration oil 6 adheres to and accumulates on the convex portion 68, and the droplets of the refrigeration oil that collide become larger than when the upper end surface 59 is flat. Therefore, in the compressor 160 according to the seventh embodiment, dissolution of the refrigeration oil into the refrigerant is suppressed more than in the configuration according to the second embodiment. Furthermore, the larger droplets of the refrigeration oil 6 tend to flow downward, making it easier for the refrigeration oil to be collected in the oil reservoir 13. Therefore, the compressor 160 according to the seventh embodiment can return the refrigeration oil to the oil reservoir more efficiently than in the second embodiment. In the third to sixth embodiments, the convex portions may be provided on the inner circumferential surfaces 60-1, 60-2, and 60-3 or the rotating shaft recessed portion 62. As a modification of the third embodiment, FIG. 13 shows a top view of the upper bearing portion 39 in which a plurality of convex portions 69 are provided circumferentially on the inner circumferential surface 60-1 of the upper bearing portion 39. In this configuration, the refrigerating machine oil 6 discharged from the second opening of the oil return pipe 50 onto the inner circumferential surface 60-1 is accumulated and agitated by the convex portions 69, resulting in larger droplets of the refrigerating machine oil 6 than in the case where only the planar inner circumferential surface 60-1 is provided. For these reasons, in the modification in which the convex portions 69 are provided on the inner circumferential surfaces 60-1, 60-2, and 60-3 and the rotating shaft recessed portion 62 in the configurations shown in the third to sixth embodiments, in addition to the effects of the third to sixth embodiments, dissolution of the refrigerating machine oil 6 into the refrigerant is further suppressed.

[0061] 6...refrigerant oil, 10...sealed container, 13...oil reservoir, 20...compression mechanism, 21a...main shaft, 21b...eccentric shaft, 21c...sub-shaft, 21...rotating shaft, 24...upper bearing, 25...lower bearing, 30...electric motor, 31...rotor, 39...upper bearing, 45...centrifugal pump, 47...oil supply passage, 48...space, 50...oil return pipe, 51...first opening, 52...second Opening, 54...fixing surface, 55...lower surface, 49...upper end of upper bearing portion, 58...sliding surface, 59...upper end surface of upper bearing portion, 60-1...inner circumferential surface, 60-2...inner circumferential surface, 60-3...inner circumferential surface, 61-1...gap portion, 61-2...gap portion, 61-3...gap portion, 61-4...gap portion, 62...rotating shaft recess, 68...protrusion, 69...protrusion, 70...outer shell, 100...compressor

Claims

1. a container that forms an outer shell and has an oil reservoir formed at the bottom inside to store refrigeration oil; an electric motor provided inside the container; a rotating shaft provided inside the container, attached to the electric motor, and rotating together with the electric motor; a compression mechanism located below the electric motor and compressing the refrigerant as the rotary shaft rotates, the electric motor includes a stator fixed to an inner periphery of the container and a rotor disposed inside the stator, the compression mechanism includes a bearing portion that supports the rotary shaft, the rotating shaft has an oil supply passage that supplies the refrigeration oil stored in the oil reservoir to the compression mechanism, and an oil return pipe that is connected to the oil supply passage and discharges the refrigeration oil into the space within the container, the oil return pipe has a first opening that opens into the oil supply passage and a second opening that opens into a space within the container below a lower surface of the rotor and above a bearing portion, the second opening is located above the first opening, The oil return pipe has the lower surface as a collision surface, and is provided in a direction such that the refrigeration oil is discharged toward the collision surface, The second opening is open toward the lower surface. Compressor.

2. A container that forms an outer shell and has an oil reservoir formed at the bottom inside to store refrigeration oil; an electric motor provided inside the container; a rotating shaft provided inside the container, attached to the electric motor, and rotating together with the electric motor; a compression mechanism that compresses the refrigerant as the rotating shaft rotates, the electric motor includes a stator fixed to an inner periphery of the container and a rotor disposed inside the stator, the compression mechanism includes a bearing portion that supports the rotary shaft, The bearing portion has an inner circumferential surface that expands radially toward an upper end, the rotating shaft has an oil supply passage that supplies the refrigeration oil stored in the oil reservoir to the compression mechanism, and an oil return pipe that is connected to the oil supply passage and discharges the refrigeration oil into the space within the container, the oil return pipe has a first opening that opens into the oil supply passage and a second opening that opens into a space within the container, the second opening is provided in the rotation shaft at a position facing the inner circumferential surface, The oil return pipe has a part of a surface of the bearing portion as a collision surface, and is provided in a direction in which the refrigeration oil is discharged toward the collision surface. Compressor.

3. A container that forms an outer shell and has an oil reservoir formed at the bottom inside to store refrigeration oil; an electric motor provided inside the container; a rotating shaft provided inside the container, attached to the electric motor, and rotating together with the electric motor; a compression mechanism that compresses the refrigerant as the rotating shaft rotates, the electric motor includes a stator fixed to an inner periphery of the container and a rotor disposed inside the stator, the compression mechanism includes a bearing portion that supports the rotary shaft, the rotating shaft has an oil supply passage that supplies the refrigeration oil stored in the oil reservoir to the compression mechanism, and an oil return pipe that is connected to the oil supply passage and discharges the refrigeration oil into the space within the container, the oil return pipe has a first opening that opens into the oil supply passage and a second opening that opens into a space within the container, the oil return pipe has a part of a surface of the bearing portion as a collision surface, and is provided in a direction in which the refrigeration oil is discharged toward the collision surface, the collision surface is an upper end surface of the bearing portion, A plurality of concave and convex portions are provided on the upper end surface, The second opening is open toward the upper end surface. Compressor.

4. A container that forms an outer shell and has an oil reservoir formed at the bottom inside to store refrigeration oil; an electric motor provided inside the container; a rotating shaft provided inside the container, attached to the electric motor, and rotating together with the electric motor; a compression mechanism that compresses a refrigerant as the rotating shaft rotates, the electric motor having a stator fixed to an inner periphery of the container and a rotor disposed inside the stator, the compression mechanism includes a bearing portion that supports the rotary shaft, the rotating shaft has an oil supply passage that supplies the refrigeration oil stored in the oil reservoir to the compression mechanism, and an oil return pipe that is connected to the oil supply passage and discharges the refrigeration oil into the space within the container, the rotating shaft has a rotating shaft recess recessed in the radial direction, an upper end of the rotary shaft recess is located higher than an upper end of the bearing portion; the second opening is provided in the rotary shaft recess, The oil return pipe has a part of a surface of the bearing portion as a collision surface, and is provided in a direction in which the refrigeration oil is discharged toward the collision surface. Compressor.

5. The compressor according to claim 2 , wherein a plurality of protrusions are provided on the inner circumferential surface.

6. The compressor according to any one of claims 1 to 4, wherein the refrigerant is any one of R1234yf, R1234ze, R32, and R290 as a single refrigerant, or a mixed refrigerant of two or more of these, or a mixed refrigerant of any one of these with another refrigerant, or a mixed refrigerant containing R1132(E), or a mixed refrigerant containing R1123.

7. 5. A refrigeration cycle device comprising: the compressor according to claim 1; a four-way valve for switching a flow direction of a refrigerant; a condenser for performing heat exchange between the refrigerant discharged from the compressor and air; a pressure reducing device for expanding the refrigerant discharged from the condenser; and an evaporator for performing heat exchange between the refrigerant discharged from the pressure reducing device and air.