Explosion-proof turbo compressor

Abstract

The present invention relates to a turbo compressor, which is capable of compressing gas and supplying it to the outside, and includes a compression unit having an impeller that compresses gas flowing in through a compressed gas inlet, a motor having a rotating shaft whose one end is connected to the impeller to rotate the impeller, a housing having a motor accommodating space for accommodating the motor, a cooling air passage that passes through the motor accommodating space and is formed so that the cooling gas accommodated therein can continuously circulate, a bearing that supports a radial load or an axial load of the rotating shaft, the bearing including at least one air bearing, and a non-contact explosion-proof unit that is a passage that is provided so that a flame generated in the internal space of the housing passes through and is cooled and then discharged to the outside, the non-contact explosion-proof unit having a width equal to or less than a predetermined value and a length equal to or more than a predetermined value, and the compressed gas passage is spatially separated from the cooling air passage, so that the gas inside the compressed gas passage cannot penetrate into the cooling air passage. According to the present invention, it is possible to provide an explosion-proof turbo compressor having an improved structure in which the air bearing increases the service life and reduces vibration noise, and even if an internal explosion occurs, the flame caused by the internal explosion is quickly cooled and then discharged to the outside.

Description

[Technical field]

[0001] The present invention relates to a turbo compressor, and more particularly to an explosion-proof turbo compressor in which an air bearing is used to increase the service life and reduce vibration noise, and in the event of an internal explosion, the resulting flame can be quickly cooled and then discharged to the outside. [Background technology]

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

[0003] In such turbo compressors, there is a problem of high heat generation due to friction between the motor and bearings caused by the high speed rotation of the impeller, and cooling is required for the motor and bearings, which are the main heat sources.

[0004] An example of a conventional turbo compressor is disclosed in Korean Patent Publication No. 10-2015-0007755. In this turbo compressor, a portion of the compressed air produced by an impeller is used to cool the motor and bearings that rotate the impeller, and then the air is returned to the impeller through an internal hole in the motor's rotating shaft.

[0005] However, in the case of a conventional turbo compressor, a part of the air compressed by the impeller is used as a cooling gas, which causes a problem of a pressure loss of the air compressed by the impeller. In addition, in the case of a conventional turbo compressor, the cooling gas is heated by the motor and the bearings and then flows back into the impeller, which causes a rise in the temperature of the air compressed by the impeller, which further reduces the compression efficiency of the turbo compressor.

[0006] In order to solve such problems, a turbo compressor has been introduced in which a compressed gas passage through which compressed air produced by an impeller passes and a cooling gas passage through which a cooling gas passes are spatially separated, so that gas inside the compressed gas passage cannot penetrate into the cooling gas passage.

[0007] On the other hand, when explosive gas is present in the vicinity or inside the turbo compressor, it is necessary to prevent an explosion due to flames generated by burnout of the motor stator or friction of the bearings inside the turbo compressor, and for this purpose a turbo compressor with an explosion-proof function is required.

[0008] Such explosion-proof turbo compressors must satisfy design requirements that ensure that even if a flame occurs from various flame sources present inside the turbo compressor, it should not propagate to explosive gases and cause an explosion. Conventional explosion-proof turbo compressors generally use rolling bearings to support the rotating shaft and fully sealed explosion-proof sealing to prevent flames generated inside from propagating to the outside.

[0009] Conventional fully sealed explosion proof sealing is a "contact type" sealing that seals the internal space by contacting the rotating shaft and / or motor housing. Although such "contact type" sealing has excellent sealing power, it has a problem that it cannot be applied to air bearings such as foil air bearings because vibrations caused by the rotation of the rotating shaft can be transmitted to the bearing. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been devised to solve the above problems, and its object is to provide an explosion-proof turbo compressor having an improved structure in which an air bearing is used to increase the service life and reduce vibration noise, and in the event of an internal explosion, the resulting flames are quickly cooled and exhausted to the outside. [Means for solving the problem]

[0011] 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 compression unit including a compressed gas inlet port through which the gas is sucked in; 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; and a compressed gas flow path connected from the compressed gas inlet port to the compressed gas outlet port; a motor having a rotating shaft, one end of which is connected to the impeller in order to rotate the impeller; a housing having a motor accommodating space for accommodating the motor; and a compressor that circulates the compressor through the motor accommodating space. a cooling air passage formed so that the cooling gas contained therein can continuously circulate; a bearing that supports a radial load or an axial load of the rotating shaft, the bearing including at least one air bearing; and a non-contact explosion-proof unit that is a passage through which a flame generated in the internal space of the housing passes, is cooled, and then discharged to the outside, the non-contact explosion-proof unit having a width equal to or less than a predetermined value and a length equal to or more than a predetermined value, wherein the compressed gas flow path is spatially separated from the cooling air path, so that gas inside the compressed gas flow path cannot permeate the cooling air path.

[0012] Here, it is preferable that the non-contact explosion-proof unit communicates the internal space of the housing with the compressed gas flow path.

[0013] Here, the non-contact explosion-proof unit is also a cylindrical space formed by the cooperation of a first surface formed on the outer circumferential surface of one end of the rotating shaft and a second surface formed on the housing.

[0014] Here, the non-contact explosion-proof unit is a conical space formed by the cooperation of a first surface formed on the outer circumferential surface of one end of the rotating shaft and a second surface formed on the housing, and it is preferable that the conical space is located within a predetermined distance from the impeller and is arranged in a direction in which the radius becomes smaller as it approaches the impeller.

[0015] Here, the non-contact explosion-proof unit has one shape selected from the group including a step shape and a wave shape so as to increase the distance that a flame generated in the internal space of the housing passes.

[0016] Preferably, the cooling device further comprises a cooling fan for forcibly circulating the cooling gas contained within the cooling air passage.

[0017] Here, it is preferable that the cooling fan is disposed at a rear end of the rotary shaft and rotated by the torque of the rotary shaft.

[0018] Here, it is preferable that a cooling fin capable of increasing heat exchange efficiency is provided between the compressed gas passage and the cooling air passage.

[0019] Here, it is preferable that the motor includes an electric conversion device for controlling the motor, the electric conversion device includes a case made of a metal material capable of hermetically housing internal heat generating components, and the case is maintained in contact with the housing to enable heat exchange.

[0020] Here, it is desirable that a cooling fin capable of increasing heat exchange efficiency is provided between the compressed gas flow path and the cooling air path, and the case is positioned in a position where it can exchange heat with the cooling fin. Effect of the Invention

[0021] According to the present invention, there is provided a turbo compressor capable of compressing gas and supplying it to the outside, comprising: a compression unit having an impeller for compressing gas flowing in through a compressed gas intake port; a motor having a rotating shaft, one end of which is coupled to the impeller in order to rotate the impeller; a housing having a motor accommodating space for accommodating the motor; a cooling air passage provided to pass through the motor accommodating space and formed so that a cooling gas accommodated therein can be continuously circulated; a bearing for supporting a radial load or an axial load of the rotating shaft, the bearing including at least one air bearing; and a non-contact explosion-proof unit having a width equal to or less than a predetermined value and a length equal to or more than a predetermined value, the compressed gas flow path being spatially separated from the cooling air path, so that gas inside the compressed gas flow path cannot penetrate into the cooling air path, thereby increasing the service life of the air bearing and reducing vibration noise. Furthermore, even if an internal explosion occurs due to a flame generated by burnout of a motor stator inside the inner housing or friction of a bearing, the resulting flame flow is cooled as it passes through the non-contact explosion-proof unit and then discharged to the outside, thereby preventing an accident in which the compressed gas explodes.

[0022] That is, according to the present invention, it is possible to provide an explosion-proof turbo compressor that simultaneously provides the positive effects of an air bearing and the positive effects of an explosion-proof turbo compressor. [Brief description of the drawings]

[0023] [Figure 1] 1 is a cross-sectional view of a turbo compressor according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a partially enlarged view of the turbo compressor shown in FIG. [Diagram 3] FIG. 2 is an enlarged view of the impeller and its surroundings of the turbo compressor shown in FIG. [Figure 4] FIG. 2 is an enlarged view of the non-contact explosion-proof unit shown in FIG. [Diagram 5]FIG. 4 is an enlarged view showing a second embodiment of the non-contact explosion-proof unit. [Figure 6] FIG. 13 is an enlarged view showing a third embodiment of the non-contact explosion-proof unit. [Figure 7] FIG. 4 is a cross-sectional view of the turbo compressor shown in FIG. 3 along line VII-VII of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0025] Fig. 1 is a cross-sectional view of a turbo compressor according to one embodiment of the present invention, and Fig. 2 is a partially enlarged view of the turbo compressor shown in Fig. 1. Fig. 3 is an enlarged view of the vicinity of the impeller of the turbo compressor shown in Fig. 1.

[0026] 1 to 3, a turbo compressor 100 according to a preferred embodiment of the present invention is a centrifugal pump that sucks in outside air by rotating an impeller at high speed, compresses it, and then sends it out, and is also called a turbo compressor or turbo blower. The turbo compressor 100 includes a housing 10, a compression unit 20, a motor 30, an air-cooling unit 40, a non-contact explosion-proof unit 50, and an electric converter 60. Hereinafter, it is assumed that the gas to be compressed is air containing an explosive substance.

[0027] The housing 10 is a housing made of a metal material and includes an outer housing 11 and an inner housing 12 .

[0028] The outer housing 11 is a cylindrical member having a cross section with the first central axis C1 as the center of a circle, and extends along the first central axis C1.

[0029] The inner housing 12 is a cylindrical member having a motor accommodating space 13 therein, has a cross section whose center is the first central axis C1, and extends along the first central axis C1.

[0030] 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.

[0031] The outer housing 11 has a shape corresponding to the inner housing 12 so as to accommodate the inner housing 12 in a surrounding manner.

[0032] As shown in FIG. 1, the left end of the outer housing 11 is open, and the right end of the outer housing 11 is coupled with a rear cover 23 of the compression unit 20, which will be described later.

[0033] The inner surface of the outer housing 11 and the outer surface of the inner housing 12 face each other with a predetermined distance therebetween.

[0034] In this embodiment, as shown in FIG. 1, a compressed gas flow path 26, which will be described later, is formed between the inner surface of the outer housing 11 and the outer surface of the inner housing 12.

[0035] A compressed gas intake port 24 is formed at the left end of the outer housing 11 so that outside air can be drawn into the compressed gas flow path 26 .

[0036] The compressed gas inlet 24 is an annular hole formed by the inner surface of the outer housing 11 and the outer surface of the inner housing 12 cooperating with each other.

[0037] The inner housing 12 has cooling fins 121 formed on its outer circumferential surface to increase heat exchange efficiency.

[0038] The cooling fins 121 are cooling fins for increasing the heat exchange efficiency between the cooling gas flow G flowing along the cooling air path 41 provided inside the inner housing 12 and the compressed gas flow F flowing along the compressed gas flow path 26.

[0039] The cooling fins 121 protrude from the outer circumferential surface of the inner housing 12 in the radial direction of the inner housing 12, and extend along the first central axis C1.

[0040] The cooling fins 121 are provided in a plurality and are spaced apart from one another and arranged in a circumferential direction of the inner housing 12 .

[0041] A portion of the distal end of the cooling fins 121 remains in contact with the inner surface of the outer housing 11 as shown in FIG.

[0042] Therefore, a large number of the compressed gas flow passages 26 are arranged in a spatially separated state by the cooling fins 121 along the circumferential direction of the first central axis C1.

[0043] The motor accommodating space 13 is provided with at least one bearing mounting portion 122 on which a journal bearing 34 and a thrust bearing 35, which will be described later, are mounted.

[0044] In this embodiment, the inner housing 12 has a substantially airtight structure that prevents the internal gas from leaking out, except for the portion through which the rotating shaft 31 described later passes and the portion in which the non-contact explosion-proof unit 50 is installed.

[0045] The compression unit 20 is a device that draws in and compresses outside air, and includes an impeller 21, a front cover 22, and a rear cover .

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

[0047] The front cover 22 is a metal member disposed in front of the impeller 21, and is provided so as to be able to cover the front end of a rotating shaft 31 which will be described later.

[0048] The rear cover 23 is a metal member disposed behind the impeller 21, and is fastened to the housing 10 by bolts or screws. In this embodiment, the rear cover 23 is coupled to the outer housing 11.

[0049] The rear cover 23 is provided in the form of a scroll casing having a passage formed so that the air passing through the impeller 21 flows in a spiral shape.

[0050] The impeller 21 compresses the air introduced through the compressed gas inlet 24, and the air compressed by the impeller 21 is discharged to the outside through a compressed gas outlet 25 as shown in FIG. 1.

[0051] The air drawn into the compressed gas inlet 24 is compressed while moving along a compressed gas flow path 26 connecting the compressed gas inlet 24 to the compressed gas outlet 25 .

[0052] The motor 30 is an electric motor that generates a 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 3, and a bearing .

[0053] The rotating shaft 31 is a rod member extending along the first central axis C1, and a front end portion of the rotating shaft 31 is coupled to the impeller 21 so as to be non-rotatable relative to the impeller 21 in order to rotate the impeller 21.

[0054] A thrust bearing runner (not shown) is provided at the rear end of the rotary shaft 31 to which a thrust bearing 35 (described later) is coupled.

[0055] The stator 32 is a stator around which a field coil is wound, and is fixedly mounted in the motor accommodating space 13 .

[0056] The rotor 33 is a rotor including a permanent magnet, and is connected to the middle part of the rotating shaft 31 .

[0057] The journal bearing 34 is a journal foil air bearing that rotatably supports the rotating shaft 31 in order to reduce frictional force generated by high-speed rotation.

[0058] The journal bearings 34 support the radial load of the rotating shaft 31 and are provided at the front and rear ends of the rotating shaft 31, respectively.

[0059] A pair of thrust bearings 35 are attached to the rear end of the rotary shaft 31. In this embodiment, the thrust bearings 35 are thrust foil air bearings.

[0060] The thrust bearing 35 is a bearing for supporting the axial load of the rotating shaft 31, and in this embodiment, as shown in FIG. 1, a pair of thrust bearings 35 are provided, each disposed on either side of the thrust bearing runner (not shown).

[0061] 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 a thrust bearing runner (not shown) of the rotating shaft 31.

[0062] The air-cooling unit 40 is a device for cooling the inner housing 12 and the motor 30 using a cooling gas, and includes a cooling air passage 41 and a cooling fan 42. Here, air or an inert gas is used as the cooling gas.

[0063] The cooling air passage 41 is a passage that accommodates the cooling gas, and is formed so that the cooling gas flow G accommodated therein continues to circulate.

[0064] The cooling air passage 41 is provided so as to continuously circulate the cooling air throughout the entire motor accommodating space 13, as shown in FIG.

[0065] It is preferable that the cooling air passages 41 are arranged rotationally symmetrically or axially symmetrically about the first central axis C1.

[0066] In this embodiment, the cooling air passage 41 is spatially separated from the compressed gas passage 26. Therefore, the compressed gas inside the compressed gas passage 26 cannot leak from the compressed gas passage 26 and permeate into the cooling air passage 41 during the process of compression.

[0067] The cooling fan 42 is a cooling fan for forcibly circulating the cooling gas contained within the cooling air passage 41, and is installed at the rear end of the motor-accommodating space 13.

[0068] In this embodiment, the cooling fan 42 is coupled to the rear end of the rotary shaft 31 so as not to be rotatable relative to the rotary shaft 31, and is rotated together with the rotary shaft 31 by the rotary force of the rotary shaft 31.

[0069] As shown in FIG. 4, the non-contact type explosion-proof unit 50 is a device through which a flame g1 generated in the internal space of the inner housing 12 passes and is cooled, and then discharged to the outside.

[0070] In this embodiment, the non-contact explosion-proof unit 50 is provided in the form of a gap or passage having a width d less than a predetermined value and a length L greater than a predetermined value, as shown in FIG.

[0071] The non-contact explosion-proof unit 50 is provided to have an axisymmetric or rotationally symmetric shape so as not to interfere with the rotational motion of the rotating shaft 31.

[0072] In this embodiment, the non-contact explosion-proof unit 50 is provided as a conical space formed by the cooperation of a first surface 311 formed on the outer circumferential surface of one end of the rotating shaft 31 and a second surface 123 formed on the inner housing 12, as shown in Figures 4 and 7.

[0073] The first surface 311 of the rotating shaft 31 and the second surface 123 of the inner housing 12 are spaced apart from each other by a predetermined distance d, so that even when the rotating shaft 31 rotates, the first surface 311 and the second surface 123 always remain in a "non-contact" state.

[0074] In this embodiment, the first surface 311 of the rotating shaft 31 is located at the front end of the rotating shaft 31, and is a tapered curved surface whose radius becomes smaller toward the impeller 21. The second surface 123 of the inner housing 12 is also a tapered curved surface having a shape corresponding to the first surface 311.

[0075] Therefore, the conical space of the non-contact type explosion-proof unit 50 is positioned within a predetermined distance from the impeller 21, and is disposed in a direction in which the radius becomes smaller as it approaches the impeller 21.

[0076] One end of the non-contact type explosion-proof unit 50 is connected to a bearing mounting portion 122 to which the journal bearing 34 arranged at the front end of the motor accommodating space 13 is attached, and the other end of the non-contact type explosion-proof unit 50 is connected to the downstream of the compressed gas flow path 26. Here, the downstream of the compressed gas flow path 26 is a position in the vicinity of just before the compressed gas flow F enters the impeller 21.

[0077] Therefore, in this embodiment, the non-contact explosion-proof unit 50 communicates the internal space of the inner housing 12 and the compressed gas flow path 26 with each other.

[0078] The electrical conversion device 60 is a device that converts electricity to control the motor 30, and converts direct current (DC) components into alternating current (AC) components, or conversely, converts alternating current (AC) components into direct current (DC) and supplies it to the motor 30.

[0079] In this embodiment, the electric converter 60 includes an inverter, also called a power inverter, for converting a direct current (DC) component into an alternating current (AC) component, and obtains a desired voltage and frequency output value through an appropriate conversion method, switching element, and control circuit.

[0080] The electric converter 60 includes a metal case 61 that houses various heat generating components therein.

[0081] The case 61 has an airtight structure so that even if various internal heat-generating components are burned and a flame occurs, the flame does not escape to the outside.

[0082] In this embodiment, the case 61 is disposed at the lower end of the outer housing 11 and is maintained in contact with the outer peripheral surface of the outer housing 11 as shown in FIG. 1 so as to be able to exchange heat with the housing 10.

[0083] In this embodiment, the case 61 is disposed at a position capable of exchanging heat with the end portion of the cooling fin 121 via the outer housing 11 as shown in FIG.

[0084] A switching module 62 is disposed at an inner upper end of the case 61, and a controller 63 is disposed at an inner lower end of the case 61.

[0085] The switching module 62 is a main heat generating component of the electrical converter 60 and includes an insulated / isolated gate bipolar transistor (IGBT).

[0086] The controller 63 is a device for controlling the overall operation of the motor 30, such as adjusting the rotation speed of the motor 30.

[0087] An example of a method for operating the turbo compressor 100 having the above-described configuration will now be described.

[0088] When the rotating shaft 31 of the motor 30 rotates, the impeller 21 and the cooling fan 42 rotate, and the air F flowing in through the compressed gas inlet 24 flows along the compressed gas passage 26 of the compression unit 20, is compressed, and is discharged to the outside through the compressed gas outlet 25. At this time, since the compressed gas passage 26 is spatially separated from the cooling air passage 41, the air flowing inside the compressed gas passage 26 cannot leak during the compression process and penetrate into the cooling air passage 41. That is, the air flow F flowing along the compressed gas passage 26 and the cooling gas flow G flowing along the cooling air passage 41 are not mixed with each other.

[0089] The cooling gas G contained inside the cooling air passage 41 is forcibly circulated by the cooling fan 42, and passes through the field coil of the stator 32, the rotating shaft 31, the rotor 33, the journal bearing 34, and the thrust bearing 35, as shown in FIG. 2.

[0090] At this time, the cooling gas G flowing around the outer periphery of the motor accommodating space 13 is rapidly cooled by the compressed gas flow F flowing between the outer housing 11 and the inner housing 12. In particular, the cooling fins 121 greatly increase the efficiency of heat exchange between the cooling gas G flowing around the outer periphery of the motor accommodating space 13 and the compressed gas flow F.

[0091] Meanwhile, if an internal explosion occurs due to a flame generated by burnout of the motor stator 32 inside the inner housing 12 or friction of the bearings 34, 35 during operation of the turbo compressor 100, a flame flow g1 is generated as a result. As shown in FIG. 4, the flame flow g1 flows into one end of the non-contact explosion-proof unit 50, passes through the non-contact explosion-proof unit 50, and is discharged to the other end of the non-contact explosion-proof unit 50.

[0092] At this time, the flame g1 generated in the internal space of the inner housing 12 is cooled as it passes through the non-contact explosion-proof unit 50, and then discharged to the outside. Therefore, even if the flame flow g1 joins the compressed gas flow F, there will be no accident in which the compressed gas F explodes.

[0093] The turbo compressor 100 having the above-mentioned configuration is a turbo compressor that compresses gas and supplies it to the outside, and includes a compression unit 20 having a compressed gas inlet 24 through which the gas is sucked, an impeller 21 that compresses the gas 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, and 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 one end of which is connected to the impeller 21 in order to rotate the impeller 21; a housing 10 having a motor accommodating space 13 that accommodates the motor 30; a cooling air passage 41 that is provided to pass through the motor accommodating space 13 and is formed so that the cooling gas G accommodated therein can be continuously circulated; an air bearing (a jar) that is a bearing that supports a radial load or an axial load of the rotating shaft 31 and has at least one or more air bearings (a jar) The housing 10 includes an air bearing (journal bearing 34, thrust bearing 35), and a non-contact type explosion-proof unit 50, which is a passage through which a flame generated in the internal space of the housing 10 passes, is cooled, and then discharged to the outside, and has a width d less than a predetermined value and a length L greater than a predetermined value. The compressed gas flow path 26 is spatially separated from the cooling air path 41, so that the gas inside the compressed gas flow path 26 cannot penetrate the cooling air path 41. This increases the service life of the air bearings (journal bearing 34, thrust bearing 35) and reduces vibration noise. In addition, even if an internal explosion occurs due to a flame generated by burning out of the motor stator 32 inside the inner housing 12 or friction between the bearings 34 and 35, the resulting flame flow g1 passes through the non-contact type explosion-proof unit 50, is cooled, and then discharged to the outside, so that an accident in which the compressed gas F explodes can be prevented.

[0094] Furthermore, the turbo compressor 100 has an advantage that the non-contact explosion-proof unit 50 connects the internal space of the housing 10 (motor accommodating space 13) and the compressed gas flow path 26 to each other, and therefore the flame flow g1 passing through the non-contact explosion-proof unit 50 is accelerated by the negative pressure generated by the compressed gas flow F flowing through the compressed gas flow path 26.

[0095] In addition, in the turbo compressor 100, the non-contact type explosion-proof unit 50 is a conical space formed by the cooperation of the first surface 311 formed on the outer circumferential surface of one end of the rotating shaft 31 and the second surface 123 formed on the housing 10, and the conical space is located within a predetermined distance from the impeller 21 and is disposed in a direction in which the radius becomes smaller as it approaches the impeller 21. Therefore, when considering that the front end of the rotating shaft 31 generally has a tapered shape, there is an advantage that the machining for forming the non-contact type explosion-proof unit 50 can be minimized compared to the case of machining other parts of the inner housing 12.

[0096] In addition, the turbo compressor 100 includes a cooling fan 42 for forcibly circulating the cooling gas G contained inside the cooling air passage 41, which has the advantage of forcibly circulating the cooling gas G contained inside the cooling air passage 41.

[0097] In addition, the turbo compressor 100 has an advantage in that the cooling fan 42 is disposed at the rear end of the rotary shaft 31 and rotates by the rotational force of the rotary shaft 31, so that a separate motor for rotating the cooling fan 42 is not required.

[0098] In addition, the turbo compressor 100 has a cooling fin 121 between the compressed gas flow path 26 and the cooling air path 41, which can increase the heat exchange efficiency, and therefore has the advantage that the heat exchange efficiency between the cooling gas G and the compressed gas F is increased.

[0099] In addition, the turbo compressor 100 includes an electric conversion device 60 for controlling the motor 30. The electric conversion device 60 includes a case 61 made of a metal material capable of hermetically housing internal heat-generating components. The case 61 is in contact with the housing 10 to enable heat exchange. Therefore, even if a burn or explosion occurs inside the case 61, the flames do not leak to the outside, and at the same time, the heat-generating components inside the case 61 can be quickly cooled.

[0100] The turbo compressor 100 is provided with cooling fins 121 between the compressed gas flow path 26 and the cooling air path 41, which can increase the heat exchange efficiency, and the case 61 is arranged in a position where it can exchange heat with the cooling fins 121, which has the advantage that the electric conversion device 60 can be cooled more quickly by the compressed gas flow F flowing between the cooling fins 121.

[0101] In this embodiment, the non-contact type explosion-proof unit 50 is formed in a "straight line" as shown in Fig. 4, but it goes without saying that instead of such a shape, the non-contact type explosion-proof unit 50 may have one of the shapes of the stepped non-contact type explosion-proof unit 50a shown in Fig. 5 and the wave-shaped non-contact type explosion-proof unit 50b shown in Fig. 6 so as to substantially increase the distance through which the flame flow g1 generated in the internal space of the housing 10 passes. Here, the non-contact type explosion-proof unit 50 is not limited to the shapes of the non-contact type explosion-proof units 50a and 50b, and may have any shape as long as it can substantially increase the distance through which the flame flow g1 passes and can always maintain the "non-contact" state between the first surface 311 and the second surface 123 even when the rotating shaft 31 rotates.

[0102] In this embodiment, as shown in Figures 4 and 7, the non-contact explosion-proof unit 50 is configured as a conical space formed by the first surface 311 formed on the outer peripheral surface of one end of the rotating shaft 31 and the second surface 123 formed on the inner housing 12 in cooperation with each other. However, it goes without saying that instead, it may be configured as a cylindrical space formed by the first surface 311 formed on the outer peripheral surface of one end of the rotating shaft 31 and the second surface 123 formed on the housing 10 in cooperation with each other.

[0103] In this embodiment, the non-contact explosion-proof unit 50 connects the internal space of the inner housing 12 to the compressed gas flow path 26, but it is also possible for the non-contact explosion-proof unit 50 to connect the internal space of the inner housing 12 to the outside of the outer housing 11.

[0104] In this embodiment, the non-contact explosion-proof unit 50 connects the bearing mounting portion 122 of the journal bearing 34 arranged at the front end of the motor accommodating space 13 to the downstream of the compressed gas flow path 26, but the non-contact explosion-proof unit 50 can also connect any point in the motor accommodating space 13 to any point in the compressed gas flow path 26.

[0105] In this embodiment, the non-contact explosion-proof unit 50 is formed as a conical space portion formed around the entire circumference of 360° along the circumferential direction of the first central axis C1 as shown in FIG. 7. However, it goes without saying that the space portions may be formed alternately or intermittently in a manner in which some space portions are formed around the circumferential direction of the first central axis C1 and some space portions are not formed.

[0106] In this embodiment, the cooling fan 42 is directly connected to the rear end of the rotating shaft 31, but it goes without saying that it can be driven by a separate electric motor.

[0107] Although a separate sealing means for airtightness is not described in this embodiment, it goes without saying that various types of sealing means can be used.

[0108] Although the present invention has been described above, it is apparent that the technical scope of the present invention is not limited to the description of the above-mentioned embodiments, and that equivalent configurations modified or changed by a person having ordinary knowledge in the art do not depart from the technical idea of ​​the present invention.

Claims

1. A turbo compressor capable of compressing gas and supplying it to the outside, a compression unit including: a compressed gas inlet through which the gas is drawn; an impeller that compresses the gas flowing in through the compressed gas inlet; a compressed gas outlet through which the gas compressed by the impeller is discharged to the outside; and a compressed gas flow path that is 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 be continuously circulated; at least one air bearing for supporting a radial load or an axial load of the rotating shaft; A non-contact explosion-proof unit is provided so that a flame generated in the internal space of the housing passes through the passage, is cooled, and is then discharged to the outside, the non-contact explosion-proof unit having a width equal to or less than a predetermined value and a length equal to or more than a predetermined value, The compressed gas flow path is spatially separated from the cooling air path, so that the gas inside the compressed gas flow path cannot permeate into the cooling air path, The turbo compressor, wherein the non-contact explosion-proof unit communicates an internal space of the housing with the compressed gas flow path.

2. 2. The turbo compressor according to claim 1, wherein the non-contact explosion-proof unit is a cylindrical space formed by a first surface formed on an outer circumferential surface of one end of the rotating shaft and a second surface formed on the housing in cooperation with each other.

3. The non-contact explosion-proof unit includes: a conical space formed by a first surface formed on an outer peripheral surface of one end of the rotating shaft and a second surface formed on the housing in cooperation with each other; The turbo compressor according to claim 1 , wherein the conical space is located within a predetermined distance from the impeller, and is disposed in a direction in which a radius of the conical space becomes smaller toward the impeller.

4. The non-contact explosion-proof unit includes:

2. The turbo compressor according to claim 1, wherein the housing has a shape selected from the group consisting of a stepped shape and a wave shape, so as to increase a distance traveled by a flame generated in the internal space of the housing.

5. 2. The turbo compressor according to claim 1, further comprising a cooling fan for forcibly circulating the cooling gas contained inside the cooling air passage.

6. 6. The turbo compressor according to claim 5, wherein the cooling fan is disposed at a rear end of the rotary shaft and rotated by a torque of the rotary shaft.

7. 2. The turbo compressor according to claim 1, further comprising a cooling fin provided between the compressed gas passage and the cooling air passage for increasing heat exchange efficiency.

8. an electric converter for controlling the motor; The electric converter includes a case made of a metal material capable of hermetically housing an internal heat generating component, The turbo compressor according to claim 1 , wherein the case is in contact with the housing so as to be capable of exchanging heat with the housing.

9. a cooling fin capable of increasing heat exchange efficiency is provided between the compressed gas flow path and the cooling air path; The turbo compressor according to claim 8, wherein the case is disposed at a position capable of heat exchange with the cooling fins.

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