Turbo compressor

Abstract

Disclosed is a turbo compressor. The turbo compressor includes a housing, a driving motor, a rotating shaft, an impeller, bearings, and a refrigerant supply passage, wherein at least a portion of the refrigerant supply passage may be provided with a phase change passage part so as to surround a motor chamber of the housing. Accordingly, a liquid refrigerant discharged from a condenser is changed in phase to a gas refrigerant by utilizing motor heat generated from the driving motor, thus eliminating the need for a refrigerant storage tank and a heater for converting the liquid refrigerant discharged from the condenser into the gas refrigerant. Therefore, it is possible to reduce manufacturing costs and / or transportation costs for the turbo compressor and / or a refrigeration cycle device including same.

Description

turbo compressor

[0001] The present invention relates to a turbocompressor that centrifugally compresses a refrigerant.

[0002] Generally, compressors can be broadly divided into positive displacement compressors and turbo compressors. Positive displacement compressors, like reciprocating or rotary compressors, utilize pistons or vanes to suck in, compress, and then discharge a fluid. Turbo compressors, on the other hand, utilize rotating elements to suck in, compress, and then discharge a fluid.

[0003] Volumetric compressors determine their compression ratio by appropriately adjusting the ratio of suction to discharge volumes to achieve the desired discharge pressure. Consequently, volumetric compressors face limitations in miniaturizing the overall compressor size relative to its capacity.

[0004] Turbocompressors are similar to turbo blowers, but have higher discharge pressure and lower flow rates. These turbocompressors increase the pressure of a continuously flowing fluid. They can be classified as axial-flow (if the fluid flows axially) or centrifugal (if the fluid flows radially).

[0005] Meanwhile, unlike volumetric compressors such as reciprocating or rotary compressors, turbocompressors struggle to achieve the desired high pressure ratio in a single compression cycle, even with optimally designed rotating impeller blade shapes. Factors such as processability, mass production, and durability pose challenges. Therefore, multistage turbocompressors are known, featuring multiple impellers arranged axially to compress fluid in multiple stages.

[0006] Multistage turbocompressors are known to compress fluid in multiple stages, with multiple impellers installed on a rotating shaft on one side of the rotor or facing each other on opposite ends of the rotating shaft with the rotor in between. For convenience, the former can be categorized as a one-side type, and the latter as a both-end type.

[0007] A uniaxial turbocompressor can minimize compressor efficiency degradation by shortening the piping or fluid passages connecting multiple impellers. However, in a uniaxial turbocompressor, the thrust of both impellers is oriented in the same direction, which increases axial oscillation. This increases the size of the thrust bearing, potentially increasing the overall compressor size. Furthermore, the increased load on the drive unit during high-speed operation can lead to overheating.

[0008] Double-ended turbocompressors have impellers with opposing thrust directions, which can suppress axial oscillation to a certain degree. This, in turn, can reduce the size of the thrust bearing and improve motor efficiency. However, double-ended compressors require complex and long piping or fluid passages to connect multiple impellers, which complicates the compressor structure. Furthermore, pressure loss can occur as the compressed fluid from one impeller travels through the long passage to the other impeller, reducing compressor efficiency.

[0009] The double-ended turbocompressor described above has axial bearings installed on either both ends or one end of the rotating shaft centered on the drive unit. Conventional turbocompressors, including double-ended turbocompressors, rotate at high speeds (e.g., 40,000 rpm or higher), so it is advantageous in terms of compressor efficiency to quickly dissipate the motor heat generated in the drive unit and the frictional heat in the axial bearings supporting the rotating shaft. Accordingly, conventional turbocompressors use static pressure bearings that guide the refrigerant passing through the condenser into the interior of the compressor and supply it to the bearings.

[0010] However, in conventional turbocompressors such as the above, a separate refrigerant storage tank and heater are installed between the outlet of the condenser and the compressor to convert the liquid refrigerant discharged from the condenser into a gaseous refrigerant and then supply it to the bearings of the compressor. This requires the refrigerant storage tank to be installed outside the compressor, which not only limits installation space but also increases manufacturing and / or transportation costs. Furthermore, the separate installation of a heater to change the phase of the liquid refrigerant in the refrigerant storage tank into a gaseous refrigerant increases manufacturing costs and may result in additional power consumption to drive the heater.

[0011] The purpose of the present invention is to provide a turbocompressor capable of reducing manufacturing costs and / or transportation costs.

[0012] Another object of the present invention is to provide a turbo compressor that can exclude a refrigerant storage tank and a heater that convert liquid refrigerant discharged from a condenser into gas refrigerant.

[0013] Another object of the present invention is to provide a turbo compressor capable of smoothly changing the phase of liquid refrigerant into gas refrigerant while excluding a refrigerant storage tank and a heater.

[0014] Another object of the present invention is to provide a turbo compressor capable of smoothly changing the phase of liquid refrigerant into gas refrigerant while eliminating a refrigerant storage tank and a heater, and at the same time increasing the pressure of the gas refrigerant.

[0015] In order to achieve the object of the present invention, a turbocompressor including a housing, a driving motor, a rotating shaft, an impeller, a bearing, and a refrigerant supply passage may be provided. The housing may have a motor room. The driving motor may be provided in the motor room of the housing to generate rotational force. The rotating shaft may transmit the rotational force of the driving motor. The impeller may be coupled to the rotating shaft to rotate and suck in and compress a refrigerant. The bearing may be provided between the housing and the rotating shaft to support the rotating shaft. The refrigerant supply passage may supply a working fluid transmitted from the outside of the housing to the bearing. The refrigerant supply passage may have a phase change passage part so as to surround at least a portion of the motor room. Through this, the liquid refrigerant discharged from the condenser is phase-changed into a gaseous refrigerant using the motor heat generated from the driving motor, thereby eliminating the refrigerant storage tank and heater that convert the liquid refrigerant discharged from the condenser into a gaseous refrigerant, thereby reducing the manufacturing cost and / or transportation cost of the turbo compressor and / or the refrigeration cycle device equipped therewith.

[0016] For example, the refrigerant supply passage may be formed by partially penetrating between the inner and outer surfaces of the housing. This shortens the gap between the drive motor and the refrigerant supply passage, allowing heat generated by the drive motor to be quickly transferred to the refrigerant passing through the refrigerant supply passage.

[0017] As another example, a housing cover may be wrapped around the outer surface of the housing, and a portion of the refrigerant supply passage may be formed on at least one of the outer surface of the housing and the inner surface of the housing cover. This simplifies the processing of the phase change passage, thereby eliminating the need for a separate refrigerant storage tank and heater, and simultaneously simplifying the processing of the compressor, including the motor housing, thereby suppressing an increase in manufacturing costs.

[0018] As another example, the phase change passage may be formed as a single passage. This simplifies the refrigerant movement path, thereby simplifying the manufacturing process for the phase change passage, and also suppresses refrigerant backflow in the phase change passage.

[0019] For example, the phase change passage section may be formed in a spiral shape. This allows the path length of the phase change passage section to be formed as long as possible, thereby increasing the heat transfer rate with the driving motor. In addition, the centrifugal force of the liquid refrigerant passing through the phase change passage section increases, thereby improving the refrigerant flow rate in the phase change passage section, thereby further increasing the pressure of the refrigerant.

[0020] In addition, the phase change passage section may be formed in a zigzag shape. This allows the flow path of the refrigerant to be unified, thereby suppressing refrigerant stagnation due to collision between refrigerants in the phase change passage section, while also ensuring sufficient heat transfer area between the refrigerant and the drive motor, thereby allowing the phase change of the refrigerant in the phase change passage section to occur smoothly.

[0021] In addition, the cross-sectional area of ​​the phase change passage may be formed to decrease from the upstream side to the downstream side with respect to the flow direction of the working fluid. Through this, the refrigerant flow rate in the phase change passage may further increase, thereby further improving the refrigerant pressure.

[0022] As another example, the phase change passage may be formed of a plurality of interconnected passages. This allows the refrigerant flow rate in the phase change passage to be increased, thereby increasing the pressure of the refrigerant supplied to the bearing.

[0023] For example, the phase change passage may include a plurality of side phase change sections and at least one phase change extension section. The plurality of side phase change sections may be formed at predetermined intervals along the longitudinal direction of the housing. The at least one phase change extension section may be formed to connect the plurality of side phase change sections. The plurality of phase change extension sections may extend along the axial direction of the rotational shaft. Through this, the flow resistance in the phase change passage section may be minimized while the actual flow length of the refrigerant may be shortened, thereby improving the flow velocity in the phase change passage section.

[0024] Specifically, among the plurality of phase change sections, the cross-sectional area of ​​the phase change section located on the downstream side with respect to the flow direction of the working fluid may be formed to be smaller than the cross-sectional area of ​​the phase change section located on the upstream side. Through this, the refrigerant flow rate in the phase change passage can be increased, thereby increasing the pressure of the refrigerant supplied to the bearing.

[0025] More specifically, the cross-sectional area of ​​the phase change extension section may be formed to decrease from the upstream side to the downstream side based on the flow direction of the working fluid.

[0026] As another example, one end of the phase change passage adjacent to the bearing may be provided with a static pressure passage. The cross-sectional area of ​​the static pressure passage may be formed to be larger than the cross-sectional area of ​​the phase change passage at the position where the static pressure passage is connected. Through this, the diffusing effect in the static pressure passage can be significantly improved, while the pressure of the refrigerant supplied to the first axial bearing and the second axial bearing can be improved.

[0027] For example, the static pressure passage section may be formed so that its cross-sectional area increases toward the bearing based on the flow direction of the working fluid.

[0028] Specifically, the static pressure passage section may be formed in an arc shape. This allows the length of the static pressure passage section to be formed as long as possible, thereby increasing the static pressure effect on the gas refrigerant.

[0029] A turbocompressor according to the present invention comprises a housing, a drive motor, a rotating shaft, an impeller, a bearing, and a refrigerant supply passage, wherein the refrigerant supply passage may be provided with a phase change passage portion so that at least a portion of the refrigerant supply passage surrounds a motor room of the housing. Accordingly, by phase-changing the liquid refrigerant discharged from a condenser into a gas refrigerant using the motor heat generated from the drive motor, a refrigerant storage tank and a heater for converting the liquid refrigerant discharged from the condenser into a gas refrigerant are eliminated, thereby reducing the manufacturing cost and / or transportation cost of a turbocompressor and / or a refrigeration cycle device including the same.

[0030] According to the present invention, a portion of the refrigerant supply passage may be formed by penetrating between the inner and outer surfaces of the housing. This shortens the gap between the drive motor and the refrigerant supply passage, allowing heat generated by the drive motor to be rapidly transferred to the refrigerant passing through the refrigerant supply passage.

[0031] According to the present invention, a turbo compressor may be configured such that a housing cover is wrapped around the outer surface of the housing, and a portion of a refrigerant supply passage may be formed on at least one of the outer surface of the housing and the inner surface of the housing cover. This simplifies the processing of the phase change passage, thereby eliminating the need for a separate refrigerant storage tank and heater, and simultaneously simplifying the processing of the compressor, including the motor housing, thereby suppressing an increase in manufacturing costs.

[0032] The turbocompressor according to the present invention can be configured such that the cross-sectional area of ​​the phase change passage portion decreases from the upstream side to the downstream side with respect to the flow direction of the working fluid. This allows the refrigerant flow rate in the phase change passage portion to further increase, thereby further enhancing the refrigerant pressure.

[0033] A turbocompressor according to the present invention is provided with a static pressure passage at one end of a phase change passage adjacent to a bearing, wherein the cross-sectional area of ​​the static pressure passage may be formed to be larger than the cross-sectional area of ​​the phase change passage at a position where the static pressure passage is connected. Through this, the diffusing effect in the static pressure passage can be significantly improved, and the pressure of the refrigerant supplied to the first axial bearing and the second axial bearing can be improved.

[0034] Fig. 1 is a schematic diagram showing a refrigeration cycle including a turbo compressor according to the present embodiment.

[0035] Fig. 2 is a perspective view showing an exploded view of a turbo compressor according to the present embodiment.

[0036] Fig. 3 is a cross-sectional view showing the inside of a turbo compressor according to the present embodiment.

[0037] Fig. 4 is a cross-sectional view of a motor housing having a refrigerant supply passage according to the present embodiment.

[0038] Figure 5 is a cross-sectional view showing the refrigerant flow in the refrigerant supply passage in Figure 4.

[0039] Fig. 6 is a cross-sectional view of a motor housing having a refrigerant supply passage according to another embodiment.

[0040] Fig. 7 is a cross-sectional view showing the refrigerant flow in the refrigerant supply passage in Fig. 6.

[0041] Fig. 8 is a cross-sectional view of a motor housing having a refrigerant supply passage according to another embodiment.

[0042] Fig. 9 is a cross-sectional view showing the refrigerant flow in the refrigerant supply passage in Fig. 8.

[0043] Fig. 10 is a perspective view showing a broken-away motor housing having a refrigerant supply passage according to another embodiment.

[0044] Fig. 11 is a cross-sectional view showing the refrigerant flow in the refrigerant supply passage in Fig. 10.

[0045] Hereinafter, a turbocompressor according to the present invention will be described in detail with reference to an embodiment illustrated in the attached drawings. In this embodiment, a double-ended and multi-stage turbocompressor is described as an example, in which a first impeller and a second impeller are installed at both ends of a rotating shaft, and an outlet of a first compression unit including the first impeller is connected to an inlet of a second compression unit including the second impeller, but is not necessarily limited thereto. For example, the axial bearing described below can be equally applied to a single-sided turbocompressor in which at least one impeller is installed at one end of a rotating shaft.

[0046] Furthermore, while the turbo compressor according to this embodiment is described primarily as being applied to a chiller system that supplies chilled water to a demand source, its application is not necessarily limited to chiller systems. For example, the turbo compressor according to this embodiment can be equally applied to a refrigeration cycle system that utilizes a refrigerant.

[0047] In addition, in the turbo compressor according to the present embodiment, the longitudinal direction of the rotation shaft is defined as the axial direction, the thickness direction of the rotation shaft is defined as the radial direction, and the suction side of each impeller (or compression unit) on the axial line is defined as the front, and the discharge side of each impeller is defined as the rear side, and the front side is defined as the first side, and the rear side is defined as the second side.

[0048] Figure 1 is a schematic diagram showing a refrigeration cycle including a turbo compressor according to the present embodiment.

[0049] Referring to Fig. 1, a refrigeration cycle device to which a turbo compressor according to the present embodiment is applied is configured such that a compressor (10), a condenser (20), an expander (30), and an evaporator (40) form a closed loop. That is, a condenser (20), an expander (30), and an evaporator (40) are sequentially connected to the discharge side of the compressor (10), and an outlet of the evaporator (40) is sequentially connected to the suction side of the compressor (10). Accordingly, the refrigerant compressed in the compressor (10) is discharged toward the condenser (20), and the refrigerant is sequentially passed through the condenser (20), the expander (30), and the evaporator (40) and is then sucked back into the compressor (10), repeating a series of processes.

[0050] However, the outlet of the condenser (20) may be branched, with the first pipe connected to the inlet of the expander (30), and the second pipe connected to the refrigerant supply passage (172) penetrating the interior of the housing (110) through the refrigerant supply pipe (171) of the refrigerant supply unit (170) to be described later. Accordingly, the high-temperature and high-pressure liquid refrigerant that has passed through the condenser (20) flows into the refrigerant supply passage (172) through the refrigerant supply unit (170), and the liquid refrigerant is converted into a gaseous refrigerant while passing through the refrigerant supply passage and then flows into the interior of the compressor (10) to cool the internal space of the compressor (10) including the bearing unit (140), and at the same time, the first axial bearing (146) and the second axial bearing (147) that form the first bearing unit (141) may be formed. The refrigerant supply section (170) including the refrigerant supply passage (172) will be described again later together with the bearing section (140).

[0051] Fig. 2 is a perspective view showing an exploded view of a turbo compressor according to the present embodiment, and Fig. 3 is a cross-sectional view showing the inside of a turbo compressor according to the present embodiment.

[0052] Referring to these drawings, the turbo compressor (10) according to the present embodiment may include a housing (110), a driving unit (hereinafter, a driving motor) (120), a rotating shaft (130), a bearing unit (140), a first compression unit (first-stage compression unit) (150), a second compression unit (second-stage compression unit) (160), and a refrigerant supply unit (170).

[0053] The housing (110) according to the present embodiment forms the exterior of the turbo compressor (10), and may include a motor housing (111), a first impeller housing (112), and a second impeller housing (113). The motor housing (111) is a member in which a drive motor (120) forming an electric part is mounted, the first impeller housing (112) is a member in which a first impeller (151) forming a first compression unit (150) is accommodated, and the second impeller housing (110) is a member in which a second impeller (161) forming a second compression unit (160) is accommodated. Accordingly, the first impeller housing (112) may be fastened to one side of the motor housing (111), and the second impeller housing (113) may be fastened to the other side of the motor housing (111).

[0054] The motor housing (111) may include a cylindrical portion (1111), a first flange portion (1112), and a second flange portion (1113). The cylindrical portion (1111) is formed in a cylindrical shape with both axial ends open, and the first flange portion (1112) and the second flange portion (1113) may extend radially from both ends of the cylindrical portion (1111). Accordingly, the first impeller housing (112) and the second impeller housing (113) may be fastened to both ends of the motor housing (111).

[0055] A motor chamber (1114) may be formed inside the motor housing (111). A stator (121), which will be described later, may be press-fitted into the center of the motor chamber (1114). Accordingly, the motor chamber (1114) may be divided into a first space (first chamber) (1114a) toward the first compression unit (150) and a second space (second chamber) (1114b) toward the second compression unit (160) based on the stator (121), which will be described later.

[0056] A bearing support portion (1115), which forms part of a first bearing portion (141) to be described later, may be formed in the middle of the first space (1114a). The bearing support portion (1115) may extend radially toward the rotation axis (130) from the inner surface of the motor housing (111) forming the first space (1114a). However, the bearing support portion (1115) may also be press-fitted into the inner surface of the motor housing (111) or may be fastened using a fastening member (not shown) such as a bolt. An example in which the bearing support portion (1115) according to the present embodiment extends as a single body from the inner surface of the motor housing (111) is illustrated.

[0057] As described above, the second space (1114b) may be substantially connected to the first space (1114a). However, a separate refrigerant connection pipe (not shown) may be connected to the motor housing (111) forming the second space (1114b). The refrigerant connection pipe may be combined with a refrigerant supply pipe (171) to be described later and connected to the outlet side of the condenser (20). Accordingly, a portion of the liquid refrigerant passing through the condenser (20) flows into the second space (1114b), and this liquid refrigerant may flow into the second radial bearing (148) connected to the second space (1114b). Accordingly, the liquid refrigerant, which is the working fluid, supports the bump foil forming the second radial bearing (148) to secure bearing force for the second compression section end of the rotary shaft (130) while cooling the second radial bearing (148) and the rotary shaft (130) facing it.

[0058] Referring to FIGS. 2 and 3, the first impeller housing (112) may include a first suction port (1121), a first impeller receiving portion (1122), a first diffuser (1123), a first volute (1124), and a first discharge port (1125). Accordingly, the refrigerant passing through the first impeller housing (112) may increase the flow rate and velocity of the refrigerant compressed by the first impeller (151) described below.

[0059] The second impeller housing (113) may be formed almost symmetrically with the first impeller housing (112) with the drive motor (120) as the center. For example, the second impeller housing (113) according to the present embodiment may include a second suction port (1131), a second impeller receiving portion (1132), a second diffuser (1133), a second volute (1134), and a second discharge port (1135). Accordingly, the refrigerant passing through the second impeller housing (113) may increase the flow rate and velocity of the refrigerant compressed by the second impeller (161) described later.

[0060] Referring to FIGS. 2 and 3, the driving motor (120) according to the present embodiment may include a stator (121) and a rotor (122).

[0061] The stator (121) may include a stator core (1211) and a stator coil (1212). The stator core (1211) is press-fitted and fixed to the motor housing (111), and the stator coil (1212) may be wound around the stator core (1211). Accordingly, a circumferential gap is generated between the two stator coils (1212), and this circumferential gap becomes a refrigerant passage that connects the first space (1114a) and the second space (1114b) of the motor housing (111) to each other.

[0062] The rotor (122) can be rotatably arranged inside the stator (121) and spaced apart from the inner surface of the stator (121). The rotor (122) includes a rotor core (1221) and a permanent magnet (1222), but the rotor core (1221) can be coupled to the rotation shaft (130) or omitted. When the rotor core (1221) is omitted, the permanent magnet (1222) can be attached to the outer surface of the rotation shaft (130) or mounted inside the rotation shaft (130). This embodiment illustrates an example in which the permanent magnet (1222) is inserted into the interior of the rotation shaft (130) so that a portion of the rotation shaft (130) forms the rotor core (1221).

[0063] Referring to FIGS. 2 and 3, the rotation shaft (130) according to the present embodiment may include a drive shaft portion (131), a first impeller shaft portion (132), and a second impeller shaft portion (133).

[0064] The drive shaft portion (131) is formed in a cylindrical shape and is rotatably inserted into the interior of the stator (121). The first impeller shaft portion (132) may be extended or assembled as a single body from one end of the drive shaft portion (131), and the second impeller shaft portion (133) may be extended or assembled as a single body from one end of the drive shaft portion (131). In this embodiment, an example is shown in which the first impeller shaft portion (132) and the second impeller shaft portion (133) are assembled to each of the two ends of the drive shaft portion (131).

[0065] A thrust runner (1321) that is axially supported by a first axial bearing (146) and a second axial bearing (147) to be described later may be formed on the first impeller shaft portion (1322). For example, the thrust runner (1321) may be formed in a disk shape by extending radially from the outer circumferential surface of the first bearing surface portion (1322).

[0066] Referring to FIG. 3, the thrust runner (1321) may be provided between the first bearing shell (143) and the bearing support member (1115) and may be axially supported. In other words, the thrust runner (1321) may form a movable side support member, and the first bearing shell (143) and the bearing support member (1115) may each form a fixed side support member. Accordingly, the rotation shaft (130) may be axially supported on both sides together with the first impeller (151) and the second impeller (161) coupled to both ends of the rotation shaft (130).

[0067] The thrust runner (1321) may be formed so that its outer circumference is spaced apart from the inner circumference of the first space (1114a). The outer diameter of the thrust runner (1321) may be formed smaller than the inner diameter of the first space (1114a). Accordingly, the coolant supplied to the first axial bearing (146) and the second axial bearing (147) through the coolant supply unit (170) described later moves toward the driving motor (120).

[0068] Although not illustrated in the drawing, the first axial bearing (146) may be provided on the first side of the thrust runner (1321), and the second axial bearing (147) may be provided on the second side of the thrust runner (1321). In this case, since both the first axial bearing (146) and the second axial bearing (147) are installed on the rotation shaft (130), the installation and assembly of the first axial bearing (146) and the second axial bearing (147) may be easy. The first axial bearing (146) and the second axial bearing (147) will be described later.

[0069] The second impeller shaft portion (133) can be inserted and fixed into the second compression portion side end (hereinafter referred to as the second end) of the drive shaft portion (131). For example, the second impeller shaft portion (133) can be welded and joined in a press-fit state to the second end of the drive shaft portion (131), similar to the first impeller shaft portion (132).

[0070] The second impeller shaft portion (133) is formed symmetrically with respect to the first impeller shaft portion (132) and the drive shaft portion (131), and since the second bearing portion (142) is not provided with an axial bearing, a thrust runner (not shown) may be excluded. However, in some cases, the second bearing portion (142) may also be provided with an axial bearing, and a thrust runner (not shown) may be provided on the second impeller shaft portion (133).

[0071] The bearing part (140) according to the present embodiment may include a first bearing part (141) and a second bearing part (142). The first bearing part (141) may be provided between the driving motor (120) and the first compression part (150), and the second bearing part (142) may be provided between the driving motor (120) and the second compression part (160). Accordingly, the bearing part (140) may stably support the first compression part (150) and the second compression part (160), which are respectively provided at both ends of the rotation shaft (130).

[0072] Referring to FIGS. 2 and 3, the first bearing portion (141) may include a first radial bearing (145), a first axial bearing (146), and a second axial bearing (147). The first radial bearing (145) may be provided in a first shaft hole (143a) forming an inner surface of the first bearing shell (143), the first axial bearing (146) may be provided on one side of the first bearing shell (143), and the second axial bearing (147) may be provided on one side of the bearing support portion (1115).

[0073] The first radial bearing (145) may be formed of a gas foil bearing. For example, the first radial bearing (145) may be formed of a bump foil (not shown) in a rough shape and a top foil (not shown) in an arc shape.

[0074] The first axial bearing (146) supports the first axial direction of the rotation shaft (130) using the pressure (static pressure) of the refrigerant supplied from the outside of the housing (110), and the second axial bearing (147) supports the second axial direction of the rotation shaft (130) using the pressure (static pressure) of the refrigerant supplied from the outside of the housing (110). The first axial bearing (146) and the second axial bearing (147) will be described later.

[0075] Referring to FIGS. 2 and 3, the second bearing portion (142) according to the present embodiment may be formed of a second radial bearing (148) provided in a second bearing shell (144). In other words, the second radial bearing (148) may be provided in a second shaft hole (144a) forming the inner circumferential surface of the second bearing shell (144).

[0076] The second radial bearing (148) may be formed of a gas foil bearing, similar to the first radial bearing (145). Accordingly, the description of the second radial bearing (148) is replaced with the description of the first radial bearing (145).

[0077] Referring to FIGS. 2 and 3, the first compression unit (150) according to the present embodiment may include a first impeller (151), a first diffuser (1123), and a first volute (1124). However, among the components forming the first compression unit (150), the first diffuser (1123) and the first volute (1124) are as described above with respect to the first impeller housing (112). That is, the first diffuser (1123) is formed between the first impeller housing (112) and the first bearing shell (143), and the first volute (1124) may be formed in the first impeller housing (112).

[0078] As previously described, the first impeller (151) forms a first compression unit (150), which is functionally a single-stage compression unit, together with the first diffuser (1123) and the first volute (1124). Accordingly, the suction side of the first impeller (151) can be connected to a refrigerant suction pipe (115), and the discharge side of the first impeller (151) can be connected to a suction side of a second impeller (161), which forms part of a two-stage compression unit (second compression unit), through a refrigerant connection pipe (116).

[0079] Referring to FIGS. 2 and 3, the second compression unit (160) according to the present embodiment may include a second impeller (161), a second diffuser (1133), and a second volute (1134). However, among the components forming the second compression unit (160), the second diffuser (1133) and the second volute (1134) are as described above with respect to the second impeller housing (113). That is, the second diffuser (1133) is formed between the second impeller housing (113) and the second bearing shell (144), and the second volute (1134) may be formed in the second impeller housing (113).

[0080] As previously described, the second impeller (161) forms a functional two-stage compression unit together with the second diffuser (1133) and the second volute (1134). Accordingly, the suction side of the second impeller (161) can be connected to the discharge side of the first impeller (151) via a refrigerant connection pipe (116), and the discharge side of the second impeller (161) can be connected to the inlet side of the condenser (20) via a refrigerant discharge pipe (117).

[0081] The turbo compressor according to the above embodiment operates as follows.

[0082] That is, when power is applied to the drive motor (120), rotational force is generated by the induced current between the stator (121) and the rotor (122), and the rotational shaft (130) rotates together with the rotor (122) by this rotational force.

[0083] Then, the rotational power of the driving motor (120) is transmitted to the first impeller (151) and the second impeller (161) by the rotation shaft (130), and the first impeller (151) and the second impeller (161) rotate simultaneously in their respective impeller receiving spaces (1122)(1132).

[0084] Then, the refrigerant that has passed through the evaporator (40) of the refrigeration cycle device flows into the first impeller receiving space (1122) through the refrigerant suction pipe (115) and the first suction port (1121), and the refrigerant moves while rotating along the first impeller (151), increasing the static pressure and simultaneously passing through the first diffuser (1123) with centrifugal force.

[0085] Then, the refrigerant passing through the first diffuser (1123) has kinetic energy that leads to an increase in pressure head by centrifugal force in the first diffuser (1123), and the centrifugally compressed high-temperature, high-pressure refrigerant is collected in the first volute (1124) and discharged from the first compression unit (150) through the first discharge port (1125).

[0086] Then, the refrigerant discharged from the first compression unit (150) is guided to the second suction port (1131) of the second impeller housing (113) forming the second compression unit (160) through the refrigerant connection pipe (116), and the refrigerant moves while rotating along the second impeller (161), and the static pressure increases again while passing through the second diffuser (1133) with centrifugal force at the same time.

[0087] Then, the refrigerant passing through the second diffuser (1133) is compressed to the desired pressure by centrifugal force, and this two-stage compressed high-temperature, high-pressure refrigerant is collected in the second volute (1134) and discharged to the condenser (20) through the second discharge port (1135) and the refrigerant discharge pipe (117), repeating a series of processes.

[0088] At this time, the first impeller (151) and the second impeller (161) receive a thrust that is pushed toward the rear of each impeller (151) (161) by the refrigerant sucked in through the first suction port (1121) and the second suction port (1131) of each impeller housing (112) (113). However, in the case of a so-called double-ended turbo compressor in which the first impeller (151) and the second impeller (161) are arranged with their backs to each other as in the present embodiment, the thrust generated from the first impeller (151) and the thrust generated from the second impeller (161) can be offset by forming opposite directions.

[0089] However, even in the case of such a double-ended turbo compressor, during actual operation, the thrust generated from the first compression unit (150) and the thrust generated from the second compression unit (160) may not be the same or constant. As a result, the rotating shaft (130) may be pushed axially toward the first compression unit (150) or the second compression unit (160), so that axial bearings (146)(147) may be separately provided on the first compression unit (150) side and / or the second compression unit (160) side.

[0090] As these axial bearings (146)(147), a hydrostatic bearing that supports the rotating shaft (130) by supplying a constant pressure from the outside can be applied. The hydrostatic bearing can suppress friction loss on the axial bearing surface by supplying a gaseous coolant of a constant pressure to the axial bearing surface.

[0091] In cases where such a static pressure bearing is applied, a separate refrigerant storage tank and heater connected to the outlet of the condenser (20) may be provided on the outside of the compressor. In this case, the liquid refrigerant delivered from the condenser (20) to the refrigerant storage tank is heated by the heater to change its phase into a gaseous refrigerant and then supplied to the axial bearing (146)(147).

[0092] However, since a relatively large component, i.e., a refrigerant storage tank, must be installed outside the compressor (10), not only will installation space be limited, but manufacturing and / or transportation costs may also increase. In addition, since a heater for changing the phase of the liquid refrigerant in the refrigerant storage tank into a gaseous refrigerant is separately installed, not only will manufacturing costs increase, but power consumption for driving the heater may also be added.

[0093] Accordingly, in the present embodiment, a phase change unit capable of changing the phase of liquid refrigerant into gas refrigerant using motor heat is provided inside the compressor (10), that is, inside the housing (110), so that the refrigerant storage tank and heater can be eliminated between the compressor (10) and the condenser (20). This not only reduces the manufacturing cost and / or transportation cost for the refrigeration cycle device including the compressor (10), but also lowers the manufacturing cost and / or power consumption of the refrigeration cycle device including the compressor.

[0094] Fig. 4 is a cross-sectional view of a motor housing having a refrigerant supply passage according to the present embodiment, and Fig. 5 is a cross-sectional view showing the refrigerant flow in the refrigerant supply passage in Fig. 4.

[0095] Referring to FIGS. 4 and 5, the turbo compressor according to the present embodiment includes a drive motor (120) installed inside a housing (110) as described above, a first compression unit (150) including a first impeller (151) may be installed at one end of a rotation shaft (130) centered around the drive motor (120), and a second compression unit (160) including a second impeller (161) may be installed at the other end of the rotation shaft (130) centered around the drive motor (120). The discharge side of the first compression unit (150) may be connected to the suction side of the second compression unit (160). Accordingly, the refrigerant is compressed while sequentially moving through the first compression unit (150) and the second compression unit (160), and then discharged toward the condenser (20).

[0096] In this case, the rotary shaft (130) is provided with a thrust runner (1321) between the drive motor (120) and the first compression unit (150), and a first axial bearing (146) and a second axial bearing (147) that axially support the rotary shaft (130) may be respectively provided on both axial sides of the thrust runner (1321). Accordingly, the rotary shaft (130) including the first impeller (151) and the second impeller (161) can be suppressed from vibrating in the axial direction due to the pressure difference between the first compression unit (150) and the second compression unit (160).

[0097] The first axial bearing (146) and the second axial bearing (147) according to the present embodiment may each be formed as a hydrostatic bearing that receives high-pressure refrigerant passing through the condenser (20) and generates axial support force. For example, the first axial bearing (146) may be formed by a first side of a first bearing shell (143) facing a first side of a thrust runner (1321) and a first bearing plate (1461) provided on the first side of the first bearing shell (143), and the second axial bearing (147) may be formed by a first side of a bearing support member (1115) facing a second side of a thrust runner (1321) and a second bearing plate (1471) provided on the first side of the bearing support member (1115).

[0098] For example, in the first bearing shell (143), a first outlet passage (1724a) and a second outlet passage (1724b), which form part of a refrigerant supply section (170) to be described later, are formed by branching off from the outlet of the static pressure passage section (1723), and the first axial bearing (146) can be connected to the first outlet passage (1724a), and the second axial bearing (147) can be connected to the second outlet passage (1724b), respectively. Accordingly, the liquid refrigerant delivered from the condenser (20) is phase-changed into a gas refrigerant while passing through the phase-change passage (1722) described later, and is then supplied to the first axial bearing (146) through the first outlet passage (1724a) and to the second axial bearing (147) through the second outlet passage (1724b), and is sprayed toward the thrust runner (1321) to axially support the thrust runner (1321).

[0099] Specifically, the first bearing shell (143) is formed in an annular shape, and a first bearing receiving groove (143b) can be formed in an annular shape on a first side of the first bearing shell (143) facing the thrust runner (1321) so as to receive a first bearing plate (1461) forming part of the first axial bearing (146). Accordingly, the first bearing plate (1461) can be axially slidably inserted into the first bearing receiving groove (143b) and supported radially by the first bearing receiving groove (143b).

[0100] In addition, the first bearing receiving groove (143b) may be connected to the first outlet passage (1724a) described above. For example, the first outlet passage (1724a) may be formed by radially penetrating the first bearing receiving groove (143b). Accordingly, the gaseous refrigerant delivered through the first outlet passage (1724a), which forms part of the refrigerant supply unit (170) to be described later, may be supplied to the first side of the thrust runner (1321) through the first bearing plate (1461) forming the first axial bearing (146).

[0101] The first bearing plate (1461) may have a first coolant passage groove (1461b) formed on a second side facing away from the first side of the thrust runner (1321). For example, the first coolant passage groove (1461b) may be formed in an annular shape by being recessed toward the thrust runner (1321) by a preset depth on the second side of the first bearing plate (1461). Accordingly, the first coolant passage groove (1461b) forms a first internal passage (146a) together with the first bearing receiving groove (143b) of the first bearing shell (143) forming the first bearing support member.

[0102] Although not shown in the drawing, the first refrigerant passage groove may be formed in the first bearing receiving groove (143b) of the first bearing shell (143), or may be formed on the second side of the first bearing plate (1461) facing the first bearing receiving groove (143b) of the first bearing shell (143).

[0103] In addition, at least one first orifice (1461d) may be formed on the first side of the first bearing plate (1461) facing the first side of the thrust runner (1321) so that the coolant moving through the first internal passage (146a) can be sprayed toward the first side of the thrust runner (1321). Accordingly, the coolant moving through the first internal passage (146a) is sprayed toward the first side of the thrust runner (1321) through each of the first orifices (1461d) to form a static pressure along the circumferential direction.

[0104] Meanwhile, a second bearing receiving groove (1115a) having an outer wall surface and an inner wall surface is formed in an annular shape on the first side of the bearing support portion (1115) facing the first bearing shell (143), and a second bearing plate (1471) formed in an annular shape can be inserted into the second bearing receiving groove (1115a) so as to slide in the axial direction.

[0105] The second bearing receiving groove (1115a) may be connected to the second outlet passage (1724b) described above. For example, the second outlet passage (1724b) may be formed by radially penetrating the second bearing receiving groove (1115a). Accordingly, the gaseous refrigerant delivered through the second outlet passage (1724b), which forms part of the refrigerant supply unit (170) described later, may be supplied to the second side of the thrust runner (1321) through the second bearing plate (1471) forming the second axial bearing (147).

[0106] The second bearing plate (1461) may have a second coolant passage groove (1471a) formed on the second side facing the thrust runner (1321). For example, the second coolant passage groove (1471a) may be formed in an annular shape by being recessed to a preset depth from the second side of the second bearing plate (1471) toward the thrust runner (1321). Accordingly, the second coolant passage groove (1471a) forms a second internal passage (147a) together with the second bearing receiving groove (1115a) of the bearing support portion (1115) forming the second bearing support member.

[0107] Although not shown in the drawing, the second refrigerant passage groove may be formed in the second bearing receiving groove (1115a) of the bearing support member (1115), or may be formed on the second side of the second bearing plate (1471) facing the second bearing receiving groove (1115a) of the bearing support member (1115).

[0108] In addition, at least one second orifice (1471b) may be formed on the first side of the second bearing plate (1471) facing the second side of the thrust runner (1321) so that the coolant moving through the second internal passage (147a) can be sprayed toward the second side of the thrust runner (1321). Accordingly, the coolant moving through the second internal passage (147a) is sprayed toward the second side of the thrust runner (1321) through each of the second orifices (1471b), thereby forming a static pressure along the circumferential direction.

[0109] The refrigerant supply unit (170) according to the present embodiment may include a refrigerant supply pipe (171) and a refrigerant supply passage (172). The refrigerant supply pipe (171) may be provided on the outside of the housing (110), and the refrigerant supply passage (172) may be provided on the inside of the motor housing (111). In other words, the refrigerant supply pipe (171) may branch from the outlet of the condenser (20) and be connected to the refrigerant supply passage (172), and the refrigerant supply passage (172) may be connected to the refrigerant supply pipe (171) and formed to penetrate between the inner and outer peripheral surfaces of the motor housing (111). Accordingly, the liquid refrigerant delivered from the condenser (20) through the refrigerant supply pipe (171) can be phase-changed by the motor heat while passing through the refrigerant supply passage (172) and guided to the first axial bearing (146) and the second axial bearing (147). As a result, the gap between the drive motor (120) and the refrigerant supply passage (172) is shortened, and the heat generated from the drive motor (120) can be quickly transferred to the refrigerant passing through the refrigerant supply passage (172).

[0110] As described above, the refrigerant supply pipe (171) is first connected to the outlet of the condenser (20), and the other end of the refrigerant supply pipe (171) can be connected to the outer surface of the motor housing (111), that is, to the inlet passage (1721) of the refrigerant supply passage (172) described later. Accordingly, a portion of the liquid refrigerant moving from the condenser (20) toward the expander (30) can move toward the refrigerant supply passage (172) through the refrigerant supply pipe (171).

[0111] A refrigerant pump (1711) may be provided in the middle of the refrigerant supply pipe (171). Accordingly, a portion of the liquid refrigerant moving from the condenser (20) toward the expander (30) may be moved quickly and smoothly toward the refrigerant supply passage (172) through the refrigerant supply pipe (171).

[0112] A check valve (1712) may be provided on the discharge side of the refrigerant pump (1711), that is, between the refrigerant pump (1711) and the refrigerant supply passage (172). Accordingly, when the refrigerant pump (1711) is stopped or the pressure of the refrigerant supply passage (172) is high, the refrigerant in the refrigerant supply passage (172) can be prevented from flowing back toward the refrigerant pump (1711).

[0113] The refrigerant supply passage (172) may include a first passage (hereinafter, inlet passage) (1721), a second passage (hereinafter, phase change passage) (1722), a third passage (hereinafter, constant pressure passage) (1723), and a fourth passage (hereinafter, outlet passage) (1724). The inlet passage (1721) is a portion that is connected to the refrigerant supply pipe (171) and forms the inlet of the refrigerant supply passage (1722), the phase change passage (1722) is a portion that changes the phase of liquid refrigerant into gas refrigerant, the constant pressure passage (1723) is a portion that changes the dynamic pressure into constant pressure to increase the pressure of the gas refrigerant, and the outlet passage (1724) is a portion that is connected to the axial bearings (146) (147) and forms the outlet of the refrigerant supply passage (172). The inlet passage (1721), phase change passage (1722), static pressure passage (1723), and outlet passage (1724) can be connected continuously.

[0114] Referring to Fig. 4, the inlet passage (1721) is formed in a hole shape, and may extend radially from the second flange portion (1113) of the motor housing (111) by a predetermined depth (length). In other words, one end of the inlet passage (1721) may be formed at the second flange portion (1113) to which the second impeller housing (113) is coupled among the two ends of the motor housing (111). Accordingly, the inlet of the refrigerant supply passage (172) may be arranged on the opposite side of the first and second axial bearings (e.g., outlet passage portions) (146) (147) with the drive motor (120) as the center.

[0115] In this case, the entrance passage (1721) may be formed as a single unit, or may be formed as a plurality of units spaced apart at a preset interval along the circumferential direction. In this embodiment, an example in which the entrance passage (1721) is formed as a single unit is illustrated.

[0116] Referring to FIG. 4, the phase change passage (1722) is formed in a hole shape and may be formed between the second flange (1113) and the first flange (1112) of the motor housing (111). In other words, one end of the phase change passage (1722) may be connected to the inlet passage (1721) in the second flange (1113) of the motor housing (111), and the other end of the phase change passage (1722) may be connected to the positive pressure passage (1723) in the first flange (1112) of the motor housing (111). Accordingly, the phase change passage (1722) may be formed across the two ends of the drive motor (120), and at least a portion of the phase change passage (1722) may overlap the drive motor in the radial direction. Through this, the phase change passage (1722) is provided to surround the driving motor (120) so that the motor heat generated from the driving motor (120) can be transmitted quickly and smoothly.

[0117] The phase change passage (1722) may be formed as a single passage or as multiple passages. In the former case, the manufacturing process for the phase change passage (1722) can be simplified by simplifying the movement path of the refrigerant, and refrigerant backflow in the phase change passage (1722) can be suppressed. In the latter case, the refrigerant flow rate in the phase change passage (1722) can be increased to increase the pressure of the refrigerant supplied to the first axial bearing (146) and the second axial bearing (147). This embodiment illustrates an example in which the phase change passage (1722) is formed as a single passage.

[0118] For example, the phase change passage (1722) according to the present embodiment may be formed in a coiled shape. In other words, the phase change passage (1722) may be formed in a spiral shape by being continuously coiled from the inlet passage (1721) toward the outlet passage (1724). Accordingly, the phase change passage (1722) may be formed as a single passage, but the path length of the phase change passage (1722) may be formed as long as possible to increase the heat transfer rate with the drive motor (e.g., stator). In addition, the centrifugal force of the liquid refrigerant passing through the phase change passage (1722) increases, thereby improving the refrigerant flow rate in the phase change passage (1722), thereby further increasing the pressure of the refrigerant supplied to the first axial bearing (146) and the second axial bearing (147).

[0119] In this case, the phase change passage (1722) can be formed in various shapes. For example, as shown in FIG. 4, the cross-sectional areas (e.g., inner diameter) (A21)(A22) between the two ends of the phase change passage (1722) can be formed to be different from each other. In other words, the cross-sectional areas (e.g., inner diameter) (A21)(A22) of the phase change passage (1722) can be formed to gradually decrease from the inlet passage (1721) to the outlet passage (1724). Accordingly, the refrigerant flow rate in the phase change passage (1722) can be further increased. However, in some cases, the cross-sectional areas (e.g., inner diameter) (A21)(A22) between the two ends of the phase change passage (1722) can be formed to be the same. In this case, the manufacturing process for the phase change passage (1722) can be simplified.

[0120] Although not shown in the drawing, the cross-sectional area of ​​the phase change passage (1722) may be formed to increase from the inlet passage (1721) to the outlet passage (1724). In this case, the refrigerant flow rate in the phase change passage (1722) is reduced, but the liquid refrigerant can quickly change phase to gas refrigerant as it expands.

[0121] Referring to FIG. 4, the static pressure passage (1723) may be formed to be connected to the phase change passage (1722). For example, the static pressure passage (1723) may extend from the outlet of the phase change passage (1722), but may be formed on the outer side of the second bearing receiving groove (1115a) of the motor housing (111).

[0122] In this case, the static pressure passage (1723) can be formed in an arc shape extending along the circumferential direction from the first flange portion (1112) of the motor housing (111) when projected in the axial direction. Accordingly, the length of the static pressure passage (1723) can be formed as long as possible, thereby increasing the static pressure effect on the gas refrigerant.

[0123] Also, in this case, the cross-sectional area (e.g., inner diameter or internal volume) of the static pressure passage (1723) can be formed to gradually increase from the inlet end connected to the phase change passage (1722) to the outlet end connected to the outlet passage (1724). Accordingly, the diffusing effect in the static pressure passage (1723) can be greatly improved, and the pressure of the refrigerant supplied to the first axial bearing (146) and the second axial bearing (147) can be improved.

[0124] Although not shown in the drawing, the static pressure passage (1723) may be formed in a chamber shape that extends axially from the outlet of the phase change passage (1722). In this case, the static pressure passage (1723) may be formed in a rectangular or square cross-sectional shape when projected radially on the rotation axis (130) so that the cross-sectional area is the same along the flow direction of the refrigerant (e.g., axial direction), or may be formed in a trapezoidal cross-sectional shape whose cross-sectional area gradually decreases along the flow direction of the refrigerant (e.g., axial direction). In the former case, processing of the static pressure passage (1723) is easy, whereas in the latter case, the flow pressure of the refrigerant may increase as the dynamic pressure of the refrigerant passing through the phase change passage (1722) is converted to static pressure in the static pressure passage (1723).

[0125] Referring to FIGS. 4 and 5, the outlet passage (1724) is connected to the other end of the static pressure passage (1723), that is, to the opposite side of the phase change passage (1722) based on the static pressure passage (1723), and may include a first outlet passage (1724a) and a second outlet passage (1724b). For example, the outlet passage (1724) may include a first outlet passage (1724a) connected to a first axial bearing (146) and a second outlet passage (1724b) connected to a second axial bearing (147).

[0126] The first outlet passage (1724a) and the second outlet passage (1724b) may be independently connected to the pressure passage (1723), or the first outlet passage (1724a) and the second outlet passage (1724b) may be branched from each other and connected in parallel. In the former case, the refrigerant may be prevented from concentrating on one axial bearing (146)(147), thereby maintaining the support force between the axial bearings (146)(147) equally, and in the latter case, the outlet passages (1724a)(1724b) on both sides may be easily processed. This embodiment illustrates an example in which the first outlet passage (1724a) and the second outlet passage (1724b) are branched from each other and connected in parallel.

[0127] The cross-sectional areas (e.g., inner diameter) of the first outlet passage (1724a) and the cross-sectional areas (e.g., inner diameter) of the second outlet passage (1724b) may be formed to be the same or different. In the former case, not only can both outlet passages (1724a)(1724b) be easily processed, but also the supporting forces of both axial bearings (146)(147) can be maintained equally. In the latter case, the supporting forces of both axial bearings (146)(147) can be maintained differentially, so that the axial rocking of the rotating body including the rotating shaft (130) can be appropriately limited. This embodiment illustrates an example in which the cross-sectional areas of the first outlet passage (1724a) and the second outlet passage (1724b) are formed to be the same.

[0128] As described above, when the refrigerant supply passage (172) is formed to terminate inside the motor housing (111), that is, between both ends of the motor housing (111), the liquid refrigerant can be converted into a gaseous refrigerant and supplied to the bearing without excluding a separate refrigerant storage tank and heater.

[0129] In other words, a portion of the liquid refrigerant that has passed through the condenser (20) is separated at the outlet of the condenser (20) and moves to the refrigerant supply passage (172) through the refrigerant supply pipe (171), and this liquid refrigerant flows into the phase change passage (1722) through the inlet passage (1721). Then, this liquid refrigerant passes between both ends of the phase change passage (1722) and is heated by the motor heat of the drive motor (120) provided inside the motor housing (111) and is phase-changed into a gas refrigerant.

[0130] Then, the gas refrigerant moves from the other end of the phase change passage (1722) to the static pressure passage (1723), and the gas refrigerant is supplied to the first axial bearing (146) and the second axial bearing (147) through the outlet passage (1724) to support the thrust runner (1321) in both axial directions. At this time, the dynamic pressure of the gas refrigerant accumulated while passing through the phase change passage (1722) is converted to static pressure in the static pressure passage (1723), and the pressure increases, so that it is supplied to the first axial bearing (146) and the second axial bearing (147). Accordingly, it is possible to smoothly secure bearing force in an axial bearing (146)(147) and / or a radial bearing (145)(148) formed of a hydrostatic bearing, while effectively preventing bearing vibration and / or bearing damage due to refrigerant expansion in the axial bearing (146)(147) and / or the radial bearing (145)(148).

[0131] In this way, in a turbo compressor using a static pressure bearing, the liquid refrigerant discharged from the condenser can be phase-changed into a gaseous refrigerant using the heat generated by the drive motor. This eliminates the need for a refrigerant storage tank and heater for converting the liquid refrigerant discharged from the condenser into a gaseous refrigerant, thereby reducing the manufacturing and / or transportation costs of the turbo compressor and / or the refrigeration cycle device equipped therewith.

[0132] Furthermore, since the refrigerant supply passage connecting the condenser outlet and the bearing inlet is formed to surround the motor chamber, the heat generated from the drive motor can be used to change the phase of the liquid refrigerant into a gaseous refrigerant. This allows for the phase change of the liquid refrigerant into a gaseous refrigerant to be smoothly achieved while eliminating the need for a refrigerant storage tank and heater to convert the liquid refrigerant discharged from the condenser into a gaseous refrigerant.

[0133] In addition, since the cross-sectional area of ​​the refrigerant supply passage is formed to narrow from the inlet side to the outlet side, the refrigerant flow rate in the refrigerant supply passage can be increased, and at the same time, a static pressure passage part is provided on the outlet side of the refrigerant supply passage, thereby enhancing the diffusing effect on the refrigerant. This increases the pressure of the gaseous refrigerant supplied to the bearing, thereby stably supporting the rotating body including the rotating shaft.

[0134] Meanwhile, there are other examples of refrigerant supply passages as follows.

[0135] That is, in the embodiment described above, the phase change passage forming part of the refrigerant supply passage is formed in a spiral shape, but in some cases, the phase change passage may be formed in a zigzag shape.

[0136] Fig. 6 is a cross-sectional view of a motor housing having a refrigerant supply passage according to another embodiment, and Fig. 7 is a cross-sectional view showing the flow of refrigerant in the refrigerant supply passage in Fig. 6.

[0137] Referring to FIGS. 6 and 7, the basic configuration and the resulting operational effects of the turbocompressor according to the present embodiment are almost similar to those of the above-described embodiment. For example, the turbocompressor according to the present embodiment includes a drive motor (120) provided in a motor housing (111), a refrigerant supply passage (172) forming part of a refrigerant supply section provided in the motor housing (111), a refrigerant supply pipe (171) connected to the outlet of the condenser (20) is connected to one end of the refrigerant supply passage (172), and a first axial bearing (146) and a second axial bearing (147) formed of a static pressure bearing may be provided on both sides of the thrust runner (1321) at the other end of the refrigerant supply passage (172).

[0138] In this case, since a phase change passage (1722) forming part of the refrigerant supply passage (172) described above is provided inside the motor housing (111), the liquid refrigerant can be phase changed into a gas refrigerant without having to separately provide a refrigerant storage tank and heater outside the motor housing (111).

[0139] In addition, in this case, a static pressure passage (1723) forming part of the refrigerant supply passage (172) described above is provided inside the motor housing (111), thereby changing the dynamic pressure into static pressure to increase the pressure of the gas refrigerant, thereby smoothly securing the bearing force in the axial bearing (146)(147) formed of a static pressure bearing.

[0140] However, in the present embodiment, the phase change passage (1722) forming part of the refrigerant supply passage (172) may be formed in a zigzag shape. For example, the phase change passage (1722) may be formed of a first-side phase change section (1722a), a second-side phase change section (1722b), and a phase change extension section (1722c). The first-side phase change section (1722a) is a section communicating with the inlet passage (1721), the second-side phase change section (1722b) is a section communicating with the positive pressure passage (1723), and the phase change extension section (1722c) is a section connecting the first-side phase change section (1722a) and the second-side phase change section (1722b).

[0141] Specifically, the first side phase change portion (1722a) is formed in an arc shape having a preset depth in the second flange portion (or one end of the cylindrical portion) (1113) of the motor housing (111), the second side phase change portion (1722b) is formed in an arc shape having a preset depth in the first flange portion (or the other end of the cylindrical portion) (1112) of the motor housing (111), and the phase change extension portion (1722c) can be formed by axially penetrating the cylindrical portion (1111) between the first flange portion (1112) and the second flange portion (1113) to connect one end of the first side phase change portion (1722a) and one end of the second side phase change portion (1722b). Accordingly, the first phase change portion (1722a) - phase change extension portion (1722c) - second phase change portion (1722b) can be connected in series.

[0142] In this case, the first side phase change unit (1722a), the second side phase change unit (1722b), and the phase change extension unit (1722c) may each be formed in multiple numbers. For example, multiple numbers of the first side phase change units (1722a) and the second side phase change units (1722b) may be formed at predetermined intervals along the circumferential direction, and one end of each first side phase change unit (1722a) and one end of each second side phase change unit (1722b) may be formed to be connected by each phase change extension unit (1722c). Accordingly, the refrigerant supply passage (172) including the phase change extension unit (1722c) may be arranged in multiple numbers along the circumferential direction of the motor housing (111) while forming a single passage. Through this, a large heat transfer area is secured between the refrigerant supply passage (172) and the drive motor (120), so that the liquid refrigerant passing through the refrigerant supply passage (172) can be quickly phase-changed into a gas refrigerant by the motor heat of the drive motor (120).

[0143] In addition, in this case, the cross-sectional area (A21) of the phase change extension (1722c) may be formed to become larger as it approaches the inlet passage (1721), and the cross-sectional area (A22) of the phase change extension (1722c) may be formed to become smaller as it approaches the outlet passage (1724). The same applies to the first-side phase change portion (1722a) and the second-side phase change portion (1722b). In other words, the cross-sectional areas of the multiple first-side phase change portions (1722a) and the multiple second-side phase change portions (1722b) may be formed to become smaller as they approach the outlet passage (1724). Accordingly, the refrigerant flow rate in the phase change passage (1722) may increase, thereby improving the dynamic pressure. As in the embodiments described above, the dynamic pressure of the refrigerant in the static pressure passage (1723) can be converted to static pressure, thereby increasing the pressure of the refrigerant supplied to each bearing.

[0144] In the case where the phase change passage (1722) is formed in a zigzag shape as described above, the flow path of the refrigerant is unified, thereby suppressing refrigerant stagnation due to collision between refrigerants in the phase change passage (1722), while also securing a sufficient heat transfer area between the refrigerant and the driving motor (120), so that the phase change of the refrigerant in the phase change passage (1722) can be smoothly performed.

[0145] Meanwhile, another embodiment of the refrigerant supply path is as follows.

[0146] That is, in the above-described embodiment, the phase change passage forming part of the refrigerant supply passage is formed as a single passage, but in some cases, the phase change passage may be formed as a plurality of passages.

[0147] Fig. 8 is a cross-sectional view of a motor housing having a refrigerant supply passage according to another embodiment, and Fig. 9 is a cross-sectional view showing the flow of refrigerant in the refrigerant supply passage in Fig. 8.

[0148] Referring to FIGS. 8 and 9, the basic configuration and the resulting operational effects of the turbocompressor according to the present embodiment are almost similar to those of the above-described embodiment. For example, the turbocompressor according to the present embodiment includes a drive motor (120) mounted in a motor housing (111), a refrigerant supply passage (172) forming a part of a refrigerant supply section (170) mounted in the motor housing (111), a refrigerant supply pipe (171) connected to the outlet of the condenser (20) is connected to one end of the refrigerant supply passage (172), and a first axial bearing (146) and a second axial bearing (147) formed of a static pressure bearing may be mounted on each side of the thrust runner (1321) at the other end of the refrigerant supply passage (172).

[0149] In this case, since a phase change passage (1722) forming part of the refrigerant supply passage (172) described above is provided inside the motor housing (111), the liquid refrigerant can be phase changed into a gas refrigerant without having to separately provide a refrigerant storage tank and heater outside the motor housing (111).

[0150] In addition, in this case, a static pressure passage (1723) forming part of the refrigerant supply passage (172) described above is provided inside the motor housing (111), thereby changing the dynamic pressure into static pressure to increase the pressure of the gas refrigerant, thereby smoothly securing the bearing force in the axial bearing (146)(147) formed of a static pressure bearing.

[0151] However, in the present embodiment, the phase change passage (1722) forming part of the refrigerant supply passage (172) may be formed of a plurality of passages. For example, the phase change passage (1722) may be formed of a first-side phase change section (1722a), a second-side phase change section (1722b), and a phase change extension section (1722c). The first-side phase change section (1722a) is a section communicating with the inlet passage (1721), the second-side phase change section (1722b) is a section communicating with the positive pressure passage (1723), and the phase change extension section (1722c) is a section connecting the first-side phase change section (1722a) and the second-side phase change section (1722b).

[0152] Specifically, the first side phase change portion (1722a) is formed in an annular shape with a preset depth in the second flange portion (or one end of the cylindrical portion) (1113) of the motor housing (111), the second side phase change portion (1722b) is formed in an annular shape with a preset depth in the first flange portion (or the other end of the cylindrical portion) (1112) of the motor housing (111), and the phase change extension portion (1722c) can be formed by axially penetrating the cylindrical portion (1111) between the first flange portion (1112) and the second flange portion (1113) to connect the first side phase change portion (1722a) and the second side phase change portion (1722b). Accordingly, the first phase change section (1722a) - phase change extension section (1722c) - second phase change section (1722b) can be connected in series. Through this, the flow resistance in the phase change passage section (1722) can be minimized while the actual flow length of the refrigerant can be shortened, thereby improving the flow velocity in the phase change passage section (1722).

[0153] In this case, the first-side phase change unit (1722a) and the second-side phase change unit (1722b) are each formed as a single unit, while the phase change extension unit (1722c) may be formed in multiple units at preset intervals along the circumferential direction. Accordingly, the refrigerant supply passage (172) including the phase change extension unit (1722c) may be arranged in multiple units along the circumferential direction of the motor housing (111) to secure a wide heat transfer area with respect to the drive motor (120). Through this, the liquid refrigerant passing through the refrigerant supply passage (1722) may be quickly phase-changed into a gas refrigerant by the motor heat of the drive motor (120).

[0154] Also, in this case, the cross-sectional area (A22) of the second-side phase change unit (1722b) may be formed smaller than the cross-sectional area (A21) of the first-side phase change unit (1722a), and the phase change extension unit (1722c) may be formed such that the cross-sectional area (A22') of the outlet end connected to the second-side phase change unit (1722b) is smaller than the cross-sectional area (A21') of the inlet end connected to the first-side phase change unit (1722a). In other words, the plurality of phase change extension units (1722c) may be formed in parallel in the axial direction, and the cross-sectional areas may be formed such that they become smaller from each inlet end to the outlet end. Accordingly, the refrigerant flow rate in the phase change passage unit (1722) may increase, thereby improving the dynamic pressure. As in the embodiment described above, the dynamic pressure of the refrigerant may be converted into static pressure in the static pressure passage unit (1723), so that the pressure of the refrigerant supplied to each bearing may increase.

[0155] In the case where the refrigerant supply passage (172) is formed by an annular passage portion and a phase change extension portion (1722c) as described above, the refrigerant supply passage (172) can be formed by being axially sunken or penetrating, thereby simplifying the processing of the refrigerant supply passage (172).

[0156] In addition, in this case, since the first phase change section (1722a) is formed widely along the circumference of the motor housing (111), not only does the liquid refrigerant in the refrigerant supply pipe quickly flow into the refrigerant supply passage (172), but also since the phase change extension section (1722c) is connected in parallel between the first phase change section (1722a) and the second phase change section (1722b) and extends in the axial direction, the liquid refrigerant flowing into the first phase change section (1722a) can quickly move toward the second phase change section (1722b) through the phase change extension section (1722c). Accordingly, it is possible to effectively suppress the occurrence of refrigerant stagnation inside the refrigerant supply passage (172).

[0157] Meanwhile, another embodiment of the refrigerant supply path is as follows.

[0158] That is, in the embodiments described above, the refrigerant supply passage is formed by penetrating the inside of the motor housing, but in some cases, the refrigerant supply passage may be formed by being wrapped around the outer surface of the motor housing.

[0159] Fig. 10 is a perspective view showing a motor housing having a refrigerant supply passage according to another embodiment, cut away, and Fig. 11 is a cross-sectional view showing the refrigerant flow in the refrigerant supply passage in Fig. 10.

[0160] Referring to FIGS. 10 and 11, the basic configuration and the resulting operational effects of the turbocompressor according to the present embodiment are almost similar to those of the above-described embodiment. For example, the turbocompressor according to the present embodiment includes a drive motor (120) installed inside a motor housing (111), a refrigerant supply passage (172) forming a part of a refrigerant supply section (170) is installed in the motor housing (111), and a refrigerant supply pipe (171) connected to the outlet of the condenser (20) is connected to one end of the refrigerant supply passage (172), and a first axial bearing (146) and a second axial bearing (147) formed of a static pressure bearing may be installed on both sides of the thrust runner at the other end of the refrigerant supply passage (172).

[0161] In this case, since a phase change passage (1722) forming part of the refrigerant supply passage (172) described above is provided inside the motor housing (111), the liquid refrigerant can be phase changed into a gas refrigerant without having to separately provide a refrigerant storage tank and heater outside the motor housing (111).

[0162] In addition, in this case, a static pressure passage (1723) forming part of the refrigerant supply passage (172) described above is provided inside the motor housing (111), thereby changing the dynamic pressure into static pressure to increase the pressure of the gas refrigerant, thereby smoothly securing the bearing force in the axial bearing (146)(147) formed of a static pressure bearing.

[0163] However, in the present embodiment, a part of the refrigerant supply passage (172) may be formed to surround the exterior of the motor housing (111), that is, the outer surface of the motor housing (111). For example, a housing cover (175) may be provided to surround the outer surface of the motor housing (111), and the phase change passage (1722) described above may be formed in a groove shape on the inner surface of the housing cover (175).

[0164] The phase change passage (1722) may be formed in a spiral shape as in the embodiment of FIG. 4 described above, or in a zigzag shape as in the embodiment of FIG. 6, or in a linear shape as in the embodiment of FIG. 8.

[0165] In addition, in these cases, the phase change passage (1722) may be formed so that the cross-sectional area of ​​the outlet connected to the static pressure passage (1723) is smaller than the cross-sectional area of ​​the inlet connected to the inlet passage (1721). The resulting operational effects are as described in the above-described embodiments.

[0166] In the case where the phase change passage (1722) is formed on the inner surface of the housing cover (175) that is in close contact with the outer surface of the motor housing (111) as described above, the processing of the phase change passage (1722) can be simplified. This makes it possible to suppress an increase in manufacturing costs by simplifying the processing of the compressor, including the motor housing (111), while eliminating a separate refrigerant storage tank and heater.

[0167] Although not illustrated in the drawing, when the housing cover (175) described above is provided, the phase change passage (1722) may be formed in a groove shape on the outer surface of the motor housing (111), or may be formed in a groove shape half on the outer surface of the motor housing (111) and half on the inner surface of the housing cover (175). In the former case, the heat transfer rate between the phase change passage (1722) and the drive motor (120) is improved, and in the latter case, the thickness of the motor housing (111) can be secured while the processability of the phase change passage (1722) can be improved.

[0168] Meanwhile, although not shown in the drawing, in the case where a part of the refrigerant supply passage (172) surrounds the outer surface of the motor housing (111), a separate housing cover as in the embodiment of FIG. 10 may be excluded, and the refrigerant supply pipe (171) may be wound several times around the cylindrical portion (1111) of the motor housing (111) to form a phase change passage (1722). In this case, the inlet passage (1721) and the phase change passage (1722) are excluded from the motor housing (111), thereby simplifying the manufacturing process for the motor housing (111).

[0169] Meanwhile, in the above-described embodiments, the first axial bearing (146) and the second axial bearing (147) are described as hydrostatic bearings, but these axial bearings (146)(147) are not necessarily limited to hydrostatic bearings. For example, the first axial bearing (146) and the second axial bearing (147) may be formed as hybrid bearings that combine foil bearings and hydrostatic bearings. In this case, the basic configuration of the turbo compressor including the refrigerant supply unit and the resulting operational effects are the same as in the above-described embodiments, and therefore, the description thereof will be replaced with the description of the above-described embodiments.

Claims

1. Housing having a motor room; A driving motor provided in the motor room of the above housing to generate rotational force; A rotary shaft that transmits the rotational power of the above driving motor; An impeller that rotates while being coupled to the above-mentioned rotating shaft to suck in and compress refrigerant; A bearing provided between the housing and the rotation shaft to support the rotation shaft; and Includes a coolant supply passage that supplies working fluid transmitted from the outside of the housing to the bearing, The above refrigerant supply passage is, A turbocompressor having a phase change passage so as to surround at least a portion of the motor room.

2. In paragraph 1, The above refrigerant supply passage is, A turbo compressor in which a portion is formed by penetrating between the inner and outer surfaces of the housing.

3. In paragraph 1, The outer surface of the above housing is covered with a housing cover, The above refrigerant supply passage is, A turbo compressor in which a portion is formed on at least one of the outer surface of the housing and the inner surface of the housing cover.

4. In paragraph 1, The above phase change passage part is, A turbocompressor formed with a single passage.

5. In paragraph 4, The above phase change passage part is, A turbocompressor formed in a spiral shape.

6. In paragraph 4, The above phase change passage part is, A turbo compressor formed in a zigzag shape.

7. In paragraph 4, The cross-sectional area of ​​the above phase change passage is A turbo compressor formed so that the flow direction of the working fluid decreases from the upstream side to the downstream side.

8. In paragraph 1, The above phase change passage part is, A turbocompressor formed by a plurality of interconnected passages.

9. In paragraph 8, The above phase change passage part is, A plurality of lateral phase change parts formed at preset intervals along the longitudinal direction of the housing; and At least one phase change extension part connecting between the plurality of side phase change parts is included, A turbo compressor in which the above plurality of phase change extension sections extend along the axial direction of the rotating shaft.

10. In paragraph 9, A turbo compressor in which the cross-sectional area of ​​a side phase change unit located on the downstream side based on the flow direction of the working fluid among the plurality of side phase change units is formed smaller than the cross-sectional area of ​​a side phase change unit located on the upstream side.

11. In paragraph 10, The cross-sectional area of ​​the above phase change extension section is A turbo compressor formed so that the flow direction of the working fluid decreases from the upstream side to the downstream side.

12. In any one of paragraphs 1 to 11, One end of the phase change passage adjacent to the bearing is provided with a static pressure passage, The cross-sectional area of ​​the above static pressure passage is A turbo compressor in which the cross-sectional area of ​​the phase change passage is formed at a position where the above-mentioned static pressure passage is connected to a larger area than that of the above-mentioned phase change passage.

13. In paragraph 12, The above static pressure passage part is, A turbo compressor formed so that the cross-sectional area increases toward the bearing based on the flow direction of the working fluid.

14. In paragraph 13, The above static pressure passage part is, A turbo compressor formed in an arc shape.

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