A turbo compressor in which a motor is located upstream of the compressed gas flow path

Abstract

The present invention relates to a turbocompressor, comprising: a motor having a rotating shaft connected at one end to an impeller to rotate the impeller; a housing having a motor accommodation space for accommodating the motor; and a cooling air passage extending through the motor accommodation space and allowing a cooling gas accommodated therein to flow, wherein a compressed gas inlet is located at the front end of the housing, the impeller is located at the rear end of the housing, the motor is disposed between the compressed gas inlet and the impeller, the rotating shaft has a hollow extending along its longitudinal direction, and the cooling air passage includes a first cooling air passage starting from the compressed gas inlet, passing through the outer circumferential surface of the rotating shaft to the impeller, and a second cooling air passage starting from the compressed gas inlet, passing through the hollow of the rotating shaft to the impeller, wherein gas drawn through the compressed gas inlet by the suction force of the impeller passes through the first and second cooling air passages to cool the motor. This invention has the advantage that the stator and rotor of the motor can be rapidly cooled using the relatively low-temperature cooling gas drawn through the compressed gas inlet.

Description

[Technical Field]

[0001] The present invention relates to a turbo compressor, and more particularly to a turbo compressor capable of quickly cooling the stator and rotor of a motor using a relatively low-temperature cooling gas drawn in through a compressed gas inlet. [Background technology]

[0002] A turbo compressor or turbo blower is a centrifugal pump that draws in external air or gas by rotating an impeller at high speed, compresses it, and then blows it out. It is widely used for powder transportation and aeration in sewage treatment plants, and more recently it has also been used in industrial processes and on automobiles.

[0003] In such a turbo compressor, high friction heat is generated between the motor and the bearings due to the high speed rotation of the impeller, and therefore cooling of the motor and the bearings, which are the main heat sources, is necessary.

[0004] An example of a conventional turbo compressor is shown in Figure 6. This turbo compressor 1 has a structure in which an impeller 51 is located in front of a motor 20, and a portion of the compressed air compressed by the impeller 51 flows into a space accommodating the motor 20, where it first cools the stator 23 of the motor 20, and then passes through a hole formed in the rear end of the rotating shaft 24 and into a hollow portion within the rotating shaft 24, thereby cooling the permanent magnets 22, which are the rotor connected to the rotating shaft 24.

[0005] The air that has cooled the permanent magnets 22 in this manner is discharged to the front of the rotating shaft 24 through a hole formed in the front end of the rotating shaft 24, and then flows back into the impeller 51 to be recompressed.

[0006] In such a conventional turbo compressor 1, the temperature of the air compressed by the impeller 51 has already risen during the compression process. After this hot air cools the stator 23 of the motor 20, the temperature of the air rises further. This further heated air then cools the permanent magnets 22, which are the rotor of the motor 20, and the cooling performance of the stator 23 and rotor 22 of the motor 20 decreases.

[0007] In particular, such problems become more serious when the motor 20 rotates at high speeds. If the heat generated by a high-speed rotating motor cannot be cooled efficiently, the permanent magnets 22 used as the rotor may be demagnetized or their performance may be reduced, resulting in a decrease in the performance of the entire motor.

[0008] Furthermore, in the conventional turbo compressor 1, part of the air compressed by the impeller 51 is used to cool the motor 20, and after the air used for cooling is heated, it flows again upstream of the impeller 51 and is recompressed, which creates a "vortex flow," and this may result in a decrease in the compression efficiency of the air that is finally discharged through the compressed air outlet 55. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been devised to solve the above-mentioned problems, and an object of the present invention is to provide a turbo compressor having an improved structure that allows the stator and rotor of a motor to be quickly cooled using a relatively low-temperature cooling gas drawn in through a compressed gas inlet. [Means for solving the problem]

[0010] In order to achieve the above object, a turbo compressor according to the present invention is a turbo compressor capable of compressing gas and supplying it to the outside, and includes: a compressed gas inlet port through which the gas is drawn; an impeller that compresses the gas introduced through the compressed gas inlet port; a compressed gas outlet port through which the gas compressed by the impeller is discharged to the outside; a compression unit having a compressed gas flow path connecting the compressed gas inlet port to the compressed gas outlet port; a motor having a rotating shaft connected at one end to the impeller to rotate the impeller; a housing having a motor accommodating space for accommodating the motor; and a cooling gas passage formed to pass through the motor accommodating space and allow a cooling gas contained therein to flow. a cooling air passage; the compressed gas inlet is disposed at a front end of the housing, the impeller is disposed at a rear end of the housing, the motor is disposed between the compressed gas inlet and the impeller, the rotating shaft includes a hollow extending along the longitudinal direction, and the cooling air passage includes a first cooling air passage starting from the compressed gas inlet, passing through the outer circumferential surface of the rotating shaft, and reaching the impeller; and a second cooling air passage starting from the compressed gas inlet, passing through the hollow of the rotating shaft, and reaching the impeller; and the gas sucked through the compressed gas inlet by the suction force of the impeller passes through the first and second cooling air passages, thereby cooling the motor.

[0011] Here, it is preferable that the first cooling air passage and the second cooling air passage are formed so that the cooling gas flows in one direction from the compressed gas inlet to the impeller.

[0012] Here, it is preferable that the first cooling air passage is formed to cool the stator of the motor.

[0013] Here, it is preferable that the second cooling air passage is formed so as to cool the rotor of the motor.

[0014] Here, it is desirable that the front end of the housing has at least one or more first through holes formed therein, through which gas sucked in from the compressed gas inlet port flows into the motor accommodating space, and the rear end of the housing has at least one or more second through holes formed therein, through which gas accommodated in the motor accommodating space flows into the impeller.

[0015] Preferably, at least one of the first through-holes and the second through-holes is arranged in a plurality of pieces at predetermined intervals along the circumferential direction of the rotary shaft.

[0016] Here, it is preferable that the compressor further includes a thrust bearing disposed at the front end of the rotary shaft, and a third cooling air passage starting from the compressed gas inlet, passing through the thrust bearing, and reaching the impeller.

[0017] Here, it is preferable that at least one third through hole is formed in the front end portion of the housing so that gas drawn in from the compressed gas intake port can flow into the thrust bearing.

[0018] Here, it is preferable that the third through hole includes a circular hole formed in the front end portion of the housing and a ring-shaped hole formed by the cooperation of the front end portion of the rotary shaft disposed in the circular hole.

[0019] Here, it is preferable that the rotating shaft includes a gas inlet hole formed at the front end of the rotating shaft and communicating with the hollow of the rotating shaft; and a gas outlet hole formed at the rear end of the rotating shaft and communicating with the hollow of the rotating shaft; and the gas outlet hole is disposed between the stator of the motor and the impeller. [Effects of the Invention]

[0020] According to the present invention, there is provided a turbo compressor capable of compressing gas and supplying it to the outside, comprising: a compressed gas inlet port through which the gas is drawn; an impeller that compresses the gas flowed in through the compressed gas inlet port; a compressed gas outlet port through which the gas compressed by the impeller is discharged to the outside; a compression unit having a compressed gas flow path connecting the compressed gas inlet port to the compressed gas outlet port; a motor having a rotary shaft whose one end is connected to the impeller to rotate the impeller; a housing having a motor accommodating space for accommodating the motor; and a cooling air passage that is formed so as to pass through the motor accommodating space and through which a cooling gas accommodated therein can flow; wherein the compressed gas inlet port is disposed at a front end of the housing. the impeller is disposed at the rear end of the housing, the motor is disposed between the compressed gas inlet and the impeller, the rotating shaft includes a hollow extending along the longitudinal direction, and the cooling air passage includes a first cooling air passage starting from the compressed gas inlet, passing through the outer circumferential surface of the rotating shaft, and reaching the impeller; and a second cooling air passage starting from the compressed gas inlet, passing through the hollow of the rotating shaft, and reaching the impeller. Gas drawn into the compressed gas inlet by the suction force of the impeller cools the motor while passing through the first and second cooling air passages, thereby providing an effect of quickly cooling the stator and rotor of the motor using the relatively low-temperature cooling gas drawn into the compressed gas inlet. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a cross-sectional view of a turbo compressor according to an embodiment of the present invention. [Figure 2] FIG. 2 is a partially enlarged view of the turbo compressor shown in FIG. [Figure 3] FIG. 3 is a partially enlarged view of the front end portion of the turbo compressor shown in FIG. [Figure 4] FIG. 3 is a partially enlarged view of the rear end portion of the turbo compressor shown in FIG. [Figure 5] FIG. 2 is a cross-sectional view of the rotating shaft and its surroundings shown in FIG. [Figure 6] FIG. 1 is a cross-sectional view of a conventional turbo compressor. DETAILED DESCRIPTION OF THE INVENTION

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0023] Fig. 1 is a cross-sectional view of a turbo compressor according to an embodiment of the present invention, and Fig. 2 is a partially enlarged view of the turbo compressor shown in Fig. 1. Fig. 3 is a partially enlarged view of the front end portion of the turbo compressor shown in Fig. 2.

[0024] 1 to 3, a turbo compressor 100 according to a preferred embodiment of the present invention is a centrifugal pump that draws in and compresses external gas by rotating an impeller at high speed, and then blows the gas to the outside. This turbo compressor 100 includes a housing 10, a compression unit 20, a motor 30, and a cooling air passage. Hereinafter, it is assumed that the gas to be compressed is air.

[0025] The housing 10 is a housing made of a metal material, and is a cylindrical member with a motor accommodating space 13 inside, has a cross section with the first central axis C1 as the center of a circle, and extends along the first central axis C1.

[0026] The motor accommodating space 13 is a space having a shape corresponding to that of the motor 30 so as to accommodate the motor 30, which will be described later.

[0027] As shown in FIG. 2, an impeller 21 of a compression unit 20 is disposed at the rear end of the housing 10.

[0028] The housing 10 is manufactured into multiple components for mounting the motor 30, and in this embodiment includes a first housing 10a, a second housing 10b, a third housing 10c, and a fourth housing 10d.

[0029] The first housing 10a is a cylindrical member having a cross section whose center is on the first central axis C1.

[0030] At least one second through-hole 12 is formed in the rear end of the first housing 10a so that the gas accommodated in the motor accommodating space 13 can flow into the impeller 21.

[0031] In this embodiment, a plurality of second through holes 12 are provided and are arranged at predetermined intervals along the circumferential direction of a rotary shaft 31, which will be described later.

[0032] The second through-hole 12 may be formed in various shapes such as a circular hole, a slit-shaped hole extending along the radial direction of the rotary shaft 31, or a fan-shaped hole whose width narrows as it approaches the rotary shaft 31.

[0033] In this embodiment, the second through-hole 12 communicates with the interior of a gas guide member 22, which will be described later.

[0034] The second housing 10b is a disk-shaped member that is detachably attached to the front end of the first housing 10a, and is shaped so that a journal bearing 34, a thrust bearing 35, and a rotating shaft 31, which will be described later, can be mounted thereon, as shown in FIG. 3.

[0035] The second housing 10b is shaped so as to be able to close the front end of the first housing 10a.

[0036] The third housing 10c is a disk-shaped member that is detachably attached to the front end of the second housing 10b, and is shaped so that a thrust bearing 35 and a rotary shaft 31, which will be described later, can be mounted thereon, as shown in FIG.

[0037] The third housing 10c is provided so as to be able to restrain a thrust bearing runner 311 and a thrust bearing 35, which will be described later, so as not to come off forward.

[0038] A circular hole 14 having a diameter large enough to allow the rotary shaft 31 to be inserted therethrough is formed in the center of the third housing 10c.

[0039] As shown in Figure 2, the second housing 10b and the third housing 10c have at least one first through hole 11 formed therein so that gas drawn in from the compressed gas intake port 24 can flow into the motor accommodating space 13.

[0040] In this embodiment, a plurality of first through holes 11 are provided and arranged in the circumferential direction of the rotary shaft 31 at predetermined intervals.

[0041] The first through hole 11 can be formed in various shapes, such as a circular hole, a slit-shaped hole extending along the radial direction of the rotary shaft 31, or a fan-shaped hole formed to become narrower as it approaches the rotary shaft 31.

[0042] The third housing 10c is formed with at least one or more third through holes 15 that allow the gas drawn in from the compressed gas intake port 24 to flow into the thrust bearing 35.

[0043] In this embodiment, the third through hole 15 includes an annular hole 15 formed by the cooperation of a circular hole 14 formed in the third housing 10c and the front end of a rotating shaft 31 (described later) disposed in the circular hole 14, as shown in FIG.

[0044] The fourth housing 10d is a disk-shaped member as shown in FIG. 1, and is a member that closes the rear end of a gas guide member 22, which will be described later.

[0045] The compression unit 20 is a device that takes in and compresses external air, and includes an impeller 21 and a gas guide member 22 .

[0046] The impeller 21 is a main component of the centrifugal pump, and is a tire equipped with a plurality of blades having curved surfaces, and is mounted so as to be capable of high-speed rotation.

[0047] The gas guide member 22 is a metal member disposed in front of the impeller 21 and serves to guide the air that flows into the impeller 21 to be compressed and the air that has been compressed by the impeller 21 .

[0048] The gas guide member 22 is provided to close the rear end of the first housing 10a.

[0049] In this embodiment, as shown in FIG. 1, the gas guide member 22 is provided in the form of a scroll casing having a flow path formed so that the air passing through the impeller 21 flows in a vortex shape.

[0050] The impeller 21 compresses the air that flows in through a compressed gas intake port 24 (described later), and the air compressed by the impeller 21 is discharged to the outside through a compressed gas discharge port 25 .

[0051] The compressed gas intake port 24 is a member that draws in the external air to be compressed, and is located at the front end of the housing 10, but in this embodiment, it is detachably connected to the front end of the second housing 10b.

[0052] The air drawn into the compressed gas inlet 24 is compressed while moving along a compressed gas flow path 26 that connects the compressed gas inlet 24 to a compressed gas outlet 25 .

[0053] The motor 30 is an electric motor that generates rotational force and is a device for supplying high-speed rotational force to the impeller 21. The motor 30 includes a rotating shaft 31, a stator 32, a rotor 33, a journal bearing 34, and a thrust bearing 35.

[0054] The rotary shaft 31 is a rod member extending along the first central axis C1, and has a rear end portion coupled to the impeller 21 so as to be non-rotatable relative to the impeller 21 in order to rotate the impeller 21.

[0055] The rotary shaft 31 includes a hollow portion H extending along a first central axis C1, which is the longitudinal direction of the rotary shaft 31.

[0056] A thrust bearing runner 311 having a position and shape corresponding to that of the thrust bearing 35 is provided at the front end of the rotary shaft 31 .

[0057] In this embodiment, the thrust bearing runner 311 is a general disk-shaped runner.

[0058] A gas inlet hole 312 communicating with the hollow portion H of the rotary shaft 31 is formed at the front end of the rotary shaft 31 .

[0059] The gas inlet hole 312 is a hole that guides the air flowing into the compressed gas inlet 24 so that it flows into the hollow portion H.

[0060] In this embodiment, the gas inlet hole 312 is located inside the circular hole 14 of the third housing 10c.

[0061] A gas outflow hole 313 that communicates with the hollow portion H of the rotary shaft 31 is formed at the rear end of the rotary shaft 31 .

[0062] The gas outlet hole 313 is a hole that guides the air that has flowed into the hollow portion H of the rotary shaft 31 to reach the impeller 21 .

[0063] In this embodiment, a plurality of gas outflow holes 313 are provided and arranged at predetermined intervals along the circumferential direction of the rotary shaft 31 .

[0064] In this embodiment, the gas outflow hole 313 is located between the stator 32 and the impeller 21 of the motor 30, and is disposed inside the gas guide member 22, as shown in FIG.

[0065] The stator 32 is a stator around which a field coil is wound, and is mounted in a fixed state in the motor accommodating space 13 .

[0066] The rotor 33 is a rotor including a permanent magnet, and is connected to the middle part of the rotating shaft 31 .

[0067] The journal bearings 34 are journal foil air bearings that rotatably support the rotating shaft 31 in order to reduce the frictional force generated by high-speed rotation, and are provided at the front and rear ends of the rotating shaft 31.

[0068] Of the journal bearings 34 , the journal bearing 34 arranged at the front end of the rotary shaft 31 is arranged behind the thrust bearing 35 .

[0069] The thrust bearings 35 are thrust foil air bearings, and a pair of them are provided, one on each side of the thrust bearing runner 311 .

[0070] In this embodiment, the thrust bearing 35 is disposed at the frontmost position of the housing 10, as shown in FIG.

[0071] There are predetermined gaps between the stator 32 and the rotor 33, between the rotating shaft 31 and the stator 32, between the rotating shaft 31 and the journal bearing 34, and between the thrust bearing 35 and the thrust bearing runner 311.

[0072] In this embodiment, the motor 30 is disposed between the compressed gas inlet 24 and the impeller 21 .

[0073] The cooling air passages include a first cooling air passage 41, a second cooling air passage 42, and a third cooling air passage 43 as passages formed so that the cooling gas accommodated therein can flow.

[0074] Here, the cooling gas is air as the gas to be compressed, which is drawn in from the compressed gas inlet 24 by the suction force of the impeller 51 .

[0075] As shown in FIG. 2, the first cooling air passage 41 is a cooling air passage that starts from the compressed gas intake port 24, passes through the outer circumferential surface of the rotary shaft 31, and reaches the impeller 21.

[0076] In this embodiment, as shown in FIG. 2, the first cooling air passage 41 starts from the compressed gas inlet 24, passes through the first through-hole 11, the front end of the motor accommodating space 13, the space between the stator 32 and the outer circumferential surface of the rotating shaft 31, and the second through-hole 12, in this order, and reaches the impeller 21.

[0077] Therefore, the first cooling air passage 41 can quickly cool the stator 32 of the motor 30.

[0078] In this embodiment, as shown in FIG. 3, the first cooling air passage 41 is configured so as to be able to cool the thrust bearing 35 by passing through the space that houses the thrust bearing runner 311 as it passes through the first through hole 11.

[0079] As shown in FIG. 2, the second cooling air passage 42 is a cooling air passage that starts from the compressed gas intake port 24, passes through the hollow portion H of the rotary shaft 31, and reaches the impeller 21.

[0080] In this embodiment, as shown in FIG. 2, the second cooling air passage 42 starts from the compressed gas inlet 24, passes through the gas inlet 312, the hollow portion H of the rotating shaft 31, and the gas outlet 313 in this order, and reaches the impeller 21.

[0081] Therefore, the second cooling air passage 42 can quickly cool the rotor 33 of the motor 30.

[0082] The third cooling air passage 43 is a cooling air passage that starts from the compressed gas inlet 24 , passes through the thrust bearing 35 , and reaches the impeller 21 .

[0083] In this embodiment, as shown in FIG. 3, the third cooling air passage 43 starts from the compressed gas inlet 24 and passes through the thrust bearing 35, the journal bearing 34, the front end of the motor accommodating space 13, the space between the stator 32 and the outer circumferential surface of the rotating shaft 31, and the second through-hole 12, in this order, to reach the impeller 21.

[0084] Therefore, the third cooling air passage 43 can quickly cool the thrust bearing 35 and the journal bearing 34.

[0085] In this embodiment, the third cooling air passage 43 merges with the first cooling air passage 41 at the rear end of the motor accommodating space 13, as shown in FIG.

[0086] As a result, the cooling air passages 41, 42, and 43 are located at the front end of the compressed gas flow path 26, and the air to be compressed that flows along the compressed gas flow path 26 from upstream of the impeller 21 toward the impeller 21 functions as a cooling gas.

[0087] An example of how the turbo compressor 100 configured as described above operates will now be described.

[0088] When the rotating shaft 31 of the motor 30 rotates, the impeller 21 rotates, and the air drawn in from the compressed gas intake port 24 by the suction force of the impeller 21 flows through the first cooling air path 41, the second cooling air path 42, and the third cooling air path 43, thereby cooling the motor 30.

[0089] The air that has cooled the motor 30 in this manner flows into the gas guide member 22, is compressed by the impeller 21, and is then discharged to the outside through the compressed gas discharge port 25.

[0090] At this time, the air flowing through the first cooling air passage 41, the second cooling air passage 42, and the third cooling air passage 43 flows in one direction from the compressed gas intake port 24 to the impeller 21, and is not recirculated to the compressed gas intake port 24 side.

[0091] As shown in FIG. 2 , the air flowing along the first cooling air path 41 starts from the compressed gas inlet 24, passes through the first through-hole 11, the front end of the motor accommodating space 13, the space between the stator 32 and the outer circumferential surface of the rotating shaft 31, and the second through-hole 12, and then reaches the impeller 21, thereby quickly cooling the outer circumferential surfaces of the stator 32 and the rotating shaft 31.

[0092] As shown in FIG. 2, the air flowing along the second cooling air passage 42 starts from the compressed gas inlet 24, passes through the gas inlet 312, the hollow portion H of the rotating shaft 31, and the gas outlet 313 in this order, and reaches the impeller 21, thereby quickly cooling the rotor 33 and the hollow portion H of the rotating shaft 31.

[0093] As shown in FIG. 3, the air flowing along the third cooling air path 43 starts from the compressed gas inlet 24, passes through the thrust bearing 35, the journal bearing 34, the front end of the motor accommodating space 13, the space between the stator 32 and the outer circumferential surface of the rotating shaft 31, and the second through-hole 12, and then reaches the impeller 21, thereby quickly cooling the thrust bearing 35, the journal bearing 34, etc.

[0094] The turbo compressor 100 having the above-described configuration is a turbo compressor that compresses gas and supplies it to the outside, and includes a compressed gas inlet 24 through which gas is drawn; an impeller 21 that compresses the gas that has flowed in through the compressed gas inlet 24; a compressed gas outlet 25 through which the gas compressed by the impeller 21 is discharged to the outside; a compression unit 20 having a compressed gas flow path 26 connecting the compressed gas inlet 24 to the compressed gas outlet 25; a motor 30 having a rotating shaft 31 whose one end is connected to the impeller 21 to rotate the impeller 21; a housing 10 having a motor accommodating space 13 that accommodates the motor 30; and a cooling air passage that passes through the motor accommodating space 13 and is formed so that a cooling gas accommodated therein can flow. The compressed gas inlet 24 is disposed at the front end of the housing 10. The impeller 21 is disposed at the rear end of the housing 10, and the motor 30 is disposed between the compressed gas inlet 24 and the impeller 21. The rotating shaft 31 includes a hollow portion H extending along the longitudinal direction. The cooling air passages include a first cooling air passage 41 that starts from the compressed gas inlet 24, passes through the outer circumferential surface of the rotating shaft 31, and reaches the impeller 21; and a second cooling air passage 42 that starts from the compressed gas inlet 24, passes through the hollow portion H of the rotating shaft 31, and reaches the impeller 21. The gas drawn into the compressed gas inlet 24 by the suction force of the impeller 21 cools the motor 30 while passing through the first cooling air passage 41 and the second cooling air passage 42, which has the advantage that the relatively low-temperature cooling gas drawn into the compressed gas inlet 24 can be used to quickly cool the stator 32 and rotor 33 of the motor 30.

[0095] Furthermore, the turbo compressor 100 has the first cooling air passage 41 and the second cooling air passage 42 formed so that the cooling gas flows in one direction from the compressed gas inlet 24 to the impeller 21 and is not recirculated. This has the advantage of providing superior compression efficiency for the impeller 21, unlike the conventional turbo compressor 1 which has a "vortex flow" in which the air used for cooling is heated and then flows back into the upstream side of the impeller to be recompressed.

[0096] Furthermore, the turbo compressor 100 has the advantage that the first cooling air passage 41 is formed to cool the stator 32 of the motor 30, and therefore the stator 32 can be quickly cooled using a relatively low-temperature cooling gas. Here, the amount of air flowing through the first cooling air passage 41 can be easily adjusted by adjusting the size and number of the first through holes 11 and the second through holes 12.

[0097] Furthermore, the turbo compressor 100 has the advantage that the second cooling air passage 42 is formed to cool the rotor 33 of the motor 30, and therefore the rotor 33 can be quickly cooled using a relatively low-temperature cooling gas. Here, the amount of air flowing through the second cooling air passage 42 can be easily adjusted by adjusting the size and number of the gas inlet holes 312, the hollow portion H, and the gas outlet holes 313.

[0098] Furthermore, the turbo compressor 100 has at least one or more first through holes 11 formed at the front end of the housing 10 so that gas drawn in from the compressed gas intake port 24 flows into the motor accommodating space 13, and at least one or more second through holes 12 formed at the rear end of the housing 10 so that gas accommodated in the motor accommodating space 13 flows into the impeller 21, which has the advantage of making it easy to form the first cooling air passage 41 so that the cooling gas flows along the longitudinal direction of the rotating shaft 31.

[0099] Furthermore, the turbo compressor 100 has an advantage in that at least one of the first through holes 11 and the second through holes 12 is arranged in a plurality of positions spaced apart at predetermined intervals along the circumferential direction of the rotating shaft 31, making it possible to easily adjust the flow rate and streamline shape of the air flowing along the first cooling air passage 41.

[0100] In addition, the turbo compressor 100 includes the thrust bearing 35 disposed at the front end of the rotary shaft 31, and the third cooling air passage 43 that starts from the compressed gas inlet 24, passes through the thrust bearing 35, and reaches the impeller 21. This has the advantage that the thrust bearing 35 can be quickly cooled using a cooling gas with a relatively low temperature.

[0101] Furthermore, the turbo compressor 100 has at least one third through hole 15 formed at the front end of the housing 10, through which gas drawn in from the compressed gas inlet 24 flows into the thrust bearing 35. This has the advantage that the flow rate and streamline shape of the air flowing along the third cooling air passage 43 can be easily adjusted.

[0102] Furthermore, the turbo compressor 100 has an advantage in that the third through hole 15 includes an annular hole 15 formed by the cooperation of the circular hole 14 formed in the front end of the housing 10 and the front end of the rotating shaft 31 arranged in the circular hole 14, making it possible to easily form the third through hole 15 without complex cutting work.

[0103] The turbo compressor 100 has a rotating shaft 31 that includes a gas inlet hole 312 formed at the front end of the rotating shaft 31 and communicating with the hollow portion H of the rotating shaft 31; and a gas outlet hole 313 formed at the rear end of the rotating shaft 31 and communicating with the hollow portion H of the rotating shaft 31. The gas outlet hole 313 is disposed between the stator 32 of the motor 30 and the impeller 21, which has the advantage that the air flowing along the second cooling air path 42 can reach the impeller 21 directly without being mixed with the air flowing along the other cooling air paths 41, 43. This makes it very easy to individually adjust the flow rate of the air flowing along the second cooling air path 42.

[0104] In this embodiment, there are no separate cooling fins inside the cooling air passage, but it goes without saying that separate cooling fins can be provided inside the cooling air passage. In this case, the cooling fins can be formed integrally with the housing 10, or can be processed as separate members and then joined by a method such as press-fitting.

[0105] In this embodiment, the bearings 34, 35 are provided as foil air bearings, but it goes without saying that other air bearings or various other bearings may be used.

[0106] Although no other sealing means for airtightness is described in this embodiment, it goes without saying that various types of sealing means can be used.

[0107] Although the present invention has been described above, the technical scope of the present invention is not limited to the contents described in the above-mentioned embodiments, and it goes without saying that equivalent configurations modified or changed by a person having ordinary knowledge in the relevant technical field do not deviate from the scope of the technical idea of ​​the present invention.

Claims

1. A turbo compressor that can compress gas and supply it to the outside, a compressed gas inlet for drawing in gas; an impeller that compresses the gas introduced through the compressed gas inlet; a compressed gas outlet for discharging the gas compressed by the impeller to the outside; a compression unit including a compressed gas flow path connected from the compressed gas inlet to the compressed gas outlet; a motor having a rotating shaft, one end of which is coupled to the impeller, for rotating the impeller; a housing having a motor accommodating space for accommodating the motor; a cooling air passage that is provided to pass through the motor accommodating space and is formed so that a cooling gas accommodated therein can flow, the compressed gas inlet is located at a front end of the housing, and the impeller is located at a rear end of the housing; the motor is disposed between the compressed gas inlet and the impeller; The rotating shaft has a hollow portion extending along a longitudinal direction, The cooling air passage is a first cooling air passage that starts from the compressed gas inlet, passes through an outer circumferential surface of the rotary shaft, and reaches the impeller; a second cooling air passage that starts from the compressed gas inlet, passes through a hollow portion of the rotary shaft, and reaches the impeller; a first cooling air passage and a second cooling air passage, the first cooling air passage passing through the first cooling air passage and the second cooling air passage, and the second cooling air passage passing through the first cooling air passage and the second cooling air passage, the first cooling air passage passing through the second cooling air passage and the second cooling air passage, the second cooling air passage passing through the first cooling air passage and the second cooling air passage, the second cooling air passage passing through the first cooling air passage and the second cooling air passage, the second cooling air passage passing through the first cooling air passage and the second cooling air passage, the first ...

2. 2. The turbo compressor according to claim 1, wherein the first cooling air passage and the second cooling air passage are formed so that the cooling gas flows in one direction from the compressed gas inlet to the impeller.

3. The turbocompressor according to claim 1 , wherein the first cooling air passage is formed to cool a stator of the motor.

4. The turbocompressor according to claim 1, wherein the second cooling air passage is formed to cool a rotor of the motor.

5. At least one first through hole is formed in the front end of the housing so that the gas drawn in through the compressed gas suction port flows into the motor accommodating space, 2. The turbo compressor according to claim 1, wherein the housing has at least one second through hole formed in a rear end portion thereof so that the gas accommodated in the motor accommodating space can flow into the impeller.

6. 6. The turbo compressor according to claim 5, wherein at least one of the first through hole and the second through hole includes a plurality of through holes arranged at predetermined intervals along the circumferential direction of the rotary shaft.

7. The turbo compressor further includes a thrust bearing disposed at a front end of the rotary shaft, 2. The turbocompressor according to claim 1, wherein the cooling air passage further includes a third cooling air passage starting from the compressed gas inlet, passing through the thrust bearing, and leading to the impeller.

8. 8. The turbo compressor according to claim 7, wherein at least one third through hole is formed in a front end portion of the housing so that the gas drawn in through the compressed gas inlet port flows into the thrust bearing.

9. The third through hole is 9. The turbocompressor according to claim 8, further comprising: an annular hole formed by cooperation of a circular hole formed in the front end portion of the housing and a front end portion of the rotary shaft disposed in the circular hole.

10. The rotation axis is a gas inlet hole formed in a front end portion of the rotary shaft and communicating with a hollow portion of the rotary shaft; a gas outlet hole formed in a rear end portion of the rotary shaft and communicating with the hollow portion of the rotary shaft, 2. The turbocompressor according to claim 1, wherein the gas outflow hole is disposed between the stator of the motor and the impeller.

Images