KR102433580B1 - Air compressor - Google Patents

Abstract

In the air compressor of the present invention, some air from the air discharge side of the impeller flows into the inside of the motor housing through the gap between the impeller and the motor housing to cool the inside of the motor, and then the air used for cooling the motor is integrated into the motor. The first air cooling unit and the second air cooling unit are configured to be cooled in sequence and then flowed into the air inlet side of the impeller through the external return pipe connected to the outside of the motor. If the cooling air is not discharged to the outside of the air compressor, It relates to an air compressor that can effectively cool a motor and bearings.

Description

air compressor {Air compressor}

The present invention relates to a structure of a cooling passage capable of cooling air heated by heat exchange while cooling an air foil bearing, a stator of a motor, a rotor, and a motor housing in an air compressor.

The air compressor is a mechanical device that generates the energy of the fluid so that the suctioned fluid can be supplied by increasing the pressure using the impeller. In addition, the air compressor is generally provided with a high-speed motor that can be rotated at a high speed by an inverter, and an airfoil journal bearing and an airfoil thrust bearing are mounted and used for high-speed rotation.

Such an air compressor is composed of a main body forming an exterior, a driving unit including an impeller provided inside the main body to pressurize the sucked air, and a control unit capable of controlling the same, and the air compressor introduced into the main body through the air intake port formed in the main body. The air is configured to be pressurized above a certain pressure through the impeller and then discharged through the air outlet.

Here, since the air compressor rotates at a high speed compared to a general motor, a lot of heat is generated in the air foil bearings and a lot of heat is also generated in the rotor and stator of the motor, so cooling is essential.

However, the conventional air compressor has a cooling flow path structure for cooling, but it is difficult to effectively cool the motor and each air foil bearing. Accordingly, a cooling flow path structure capable of improving the cooling efficiency of the internal components of the air compressor is required. do.

KR 10-1580877 B1 (2015.12.22.)

The present invention has been devised to solve the above problems, and an object of the present invention is to provide an air compressor capable of effectively cooling the motor and bearings without discharging the cooling air that has cooled the motor to the outside of the air compressor. will provide

The air compressor of the present invention for achieving the object as described above, the stator and the rotor is provided therein, the rotor is rotatably coupled to the motor housing; an impeller housing coupled to one side of the motor housing and communicating with the inside to form an inlet through which external air is introduced and an outlet through which air is discharged, and communicating with the inside of the motor housing; an impeller provided inside the impeller housing and coupled to one end of the rotor; First air coupled to the other side of the motor housing, a first cooling air passage is formed therein, an inlet and an outlet communicating with the first cooling air passage are formed, the inlet communicating with the interior of the motor housing cooling unit; a cooling water passage passing through the motor housing and a second cooling air passage passing through the motor housing adjacent to the cooling water passage, wherein one end of the second cooling air passage is connected to an outlet of the first cooling air passage 2 air cooling unit; and an external return pipe provided outside the motor housing and the impeller housing, one end connected to the second cooling air passage and the other end connected to the inlet of the impeller housing; may be included.

In addition, the air introduced into the motor housing through a gap between the impeller and the motor housing on the air discharge side of the impeller is heated by heat exchange with the stator and the rotor while passing through the motor housing, and then the first air The air is firstly cooled by flowing into the cooling unit and radiating heat to the outside. After that, the air passes through the second air cooling unit and is secondarily cooled by the cooling water, and then the air flows into the inlet side of the impeller housing through the external return pipe. can be

In addition, the first air cooling unit may have a plurality of heat dissipation fins protruding from an inner surface forming the first cooling air flow path.

In addition, a pair of air foil journal bearings coupled to the bearing mounting portions formed on both sides of the motor housing, spaced apart from both sides of the rotor, and supporting a radial load so that the rotor is rotatable; a thrust runner coupled to the other end of the rotor and disposed between the other bearing mounting part of the motor housing and the first air cooling part; and a pair of air foil thrust bearings interposed between a bearing mounting portion adjacent to the thrust runner and the thrust runner and between the thrust runner and the first air cooling portion to support an axial load so that the thrust runner is rotatable. It may be made to further include.

In addition, the air passing through the gap between the impeller and the motor housing on the air discharge side of the impeller is an air foil journal bearing disposed on one side, between the stator and the rotor, and an air foil journal bearing disposed on the other side, the pair of After passing through one or more air foil thrust bearings among the air foil thrust bearings in sequence, the air may be introduced into the first cooling unit.

In addition, through-holes penetrating both surfaces are formed in the bearing mounting portions on both sides of the motor housing, and the air passing through the gap between the impeller and the motor housing on the air discharge side of the impeller is an air foil journal bearing disposed on one side and one side of the motor housing. It is branched to pass through the through hole, and the air that has passed between the stator and the rotor may be branched to pass through the air foil journal bearing disposed on the other side and the through hole of the other side.

In addition, the first air cooling unit may have an opening penetrating inside and outside the central portion of a side facing the thrust runner, and the opening may communicate with an air foil thrust bearing side disposed on the other side of the thrust runner. .

In addition, the first air cooling unit may be formed in a form in which a side facing the thrust runner is blocked.

In addition, the first air cooling unit may be provided with a diaphragm forming an air flow path therein.

In addition, the air compressor, characterized in that the diaphragm is formed with a communication hole passing through both surfaces.

The air compressor of the present invention has an advantage in that the cooling effect of the stator and rotor of the motor, the airfoil journal bearing and the airfoil thrust bearing is improved.

In addition, since the cooling air cooled inside the motor is not discharged to the outside of the air compressor, the outside air may not be polluted, and there is an advantage in that there is no need for a separate air discharge structure in the facility or installation space where the air compressor is installed. .

1 and 2 are a front cross-sectional view and a right side view showing an air compressor according to a first embodiment of the present invention.
3 is a partial cross-sectional view showing an air compressor according to a second embodiment of the present invention.
4 is a partial cross-sectional view showing an air compressor according to a third embodiment of the present invention.
5 is a partial cross-sectional view showing an air compressor according to a fourth embodiment of the present invention.

Hereinafter, the air compressor of the present invention as described above will be described in detail with reference to the accompanying drawings.

<Example 1>

1 and 2 are a front cross-sectional view and a right side view showing an air compressor according to a first embodiment of the present invention.

As shown, the air compressor according to the first embodiment of the present invention is largely a motor housing 100 , a stator 200 , a rotor 300 , an impeller 400 , an impeller housing 410 , and a first air cooling. It may be configured to include a unit 600 , a second air cooling unit 700 , and an external return pipe 800 . In addition, the air compressor according to the present invention may further include a pair of airfoil journal bearings 510 and 520 , a thrust runner 311 , and a pair of airfoil thrust bearings 530 and 540 .

The motor housing 100 is a part that forms the outer shape of the air compressor, and may include a body and a pair of bearing mounting parts coupled to both ends of the body. The body of the motor housing 100 has an empty interior and may be formed in a substantially cylindrical shape with both ends open, and the front bearing mounting unit 110 is coupled to one end of the body and the rear bearing mounting unit 120 is coupled to the other end of the body. can Here, the front side may be the inlet 411 side of the impeller housing 410, which is the side through which air flows from the left side in the drawing, and the rear side may be the side with the first air cooling unit 600 on the right side in the drawing. In addition, the front bearing mounting unit 110 and the rear bearing mounting unit 120 may be formed in the form of a cover to cover and block the open end of the body, and a hole passing through both surfaces may be formed in the center, respectively. Thus, the front airfoil journal bearing 510 is inserted and mounted in the hole of the front bearing mounting unit 110, and the rear airfoil journal bearing 520 is inserted and mounted in the hole of the rear bearing mounting unit 120. can In addition, a through hole 111 penetrating both surfaces may be formed in the front bearing mounting unit 110 , and the through hole 111 is located radially outward from the hole in which the front air foil journal bearing 510 is mounted. It may be located inside the radial direction rather than the outer diameter of the impeller 400 . In addition, through-holes 121 penetrating both surfaces of the rear bearing mounting part 120 may be formed, and the through-holes 121 may be located radially outside the outer diameter of the thrust runner 311 .

The stator 200 may be provided inside the motor housing 100 , and the stator 200 may be fixed in contact with the inner circumferential surface of the motor housing 100 . In addition, the stator 200 may be disposed such that the coil is wound around the core so that the end turns of the coil face the front side and the rear side. In addition, the stator 200 may be formed in a form in which the central portion is perforated through both surfaces. In addition, the stator 200 has a coil wound on the teeth of the core, and the teeth on which the coil is wound are arranged to be spaced apart in the circumferential direction to form a flow path through which air can flow between the teeth.

The rotor 300 is disposed in a form inserted through the central portion of the stator 200 , and the rotor 300 may be disposed to be spaced apart from the inside of the stator 200 . And the rotor 300 may be configured to include a rotation shaft 310 and a magnet 320, the magnet 320 may be coupled to the outside of the central portion in the axial direction of the rotation shaft 310. In addition, one side of the rotation shaft 310 in the axial direction is inserted into the inner side of the front airfoil journal bearing 510 to be rotatably supported, and the other side in the axial direction is inserted into the inner side of the rear airfoil journal bearing 520 , It may be rotatably supported. Thus, the rotor 300 can be radially supported by the two airfoil journal bearings.

The impeller housing 410 is coupled to the front side, which is one side of the motor housing 100 , and the impeller 400 may be disposed in an internal space formed by the coupling of the impeller housing 410 and the motor housing 100 . And the impeller housing 410 may be formed with an inlet 411 and a discharge port 412 communicating with the inside, an inlet 411 through which external air is introduced is formed on the front side, and is radially spaced apart from the inlet 411. A discharge port 412 through which the pressurized air is discharged may be formed at the designated position.

The impeller 400 is provided inside the impeller housing 410 , and the impeller 400 may be coupled to one end of the rotation shaft 310 of the rotor 300 . Thus, when the rotor 300 is rotated, the impeller 400 is rotated together, and external air is sucked through the inlet 411 of the impeller housing 410 by the rotation of the impeller 400, and the pressure is increased through the impeller 400. After that, it may be pressure-feed to a predetermined position through the discharge port 412 . In addition, various seal structures such as sawtooth shapes may be formed in the radial outer side of the impeller 400 and the front bearing mounting portion 110 at a position corresponding thereto, and the radial outer side of the impeller 400 by the seal structure described above. The flow of air through the gap between the end and the front bearing mounting part 110 may be restricted. However, some air may be introduced into the motor housing 100 through a gap between the seal structure of the front bearing mounting part 110 at the radially outer end of the impeller 400 which is the discharge side.

The thrust runner 311 is located at the other end of the rotation shaft 310 of the rotor 300 , and the thrust runner 311 may be integrally formed with the rotation shaft 310 . In addition, the thrust runner 311 may be formed in a disk shape, and may be disposed on the right side of the rear bearing mounting unit 120 . In addition, the front air foil thrust bearing 530 may be interposed between the rear bearing mounting unit 120 and the thrust runner 311 , and the front air foil thrust bearing 530 may be formed by the rear bearing mounting unit 120 . It can be installed on the right side of the

The first air cooling unit 600 may be formed in the form of a chamber in which a first cooling air flow path 610 through which air can flow is formed, and an inlet 611 communicating with the first cooling air flow path 610 . and an outlet 612 may be formed. In addition, the first air cooling unit 600 may be coupled to the rear bearing mounting unit 120 , and the thrust runner 311 may be disposed between the first air cooling unit 600 and the rear bearing mounting unit 120 . can At this time, the space between the first air cooling unit 600 and the rear bearing mounting unit 120 may be formed to be larger than the thickness and outer diameter of the thrust runner 311 so that the thrust runner 311 can rotate smoothly. In addition, a seating groove in which the thrust runner 311 is placed may be concavely formed in the rear bearing mounting part 120 , and a through hole 121 may be connected to the seating groove, and the through hole 121 may be formed in the front side air. It may be disposed radially outward than the foil thrust bearing 530 . In addition, the inlet 611 formed in the first air cooling unit 600 may be formed at a position corresponding to the through hole 121 , and may be located radially outward than the rear air foil thrust bearing 540 . have. In addition, in the rear bearing mounting portion 120, the front air foil thrust bearing 530 and the rear air foil journal bearing 520 are adjacent to each other in the motor housing 100. Air is passed in a diagonal direction. A through hole 122 that can be formed may be further formed. In addition, the outlet 612 may be formed at various positions, and may be located above the first air cooling unit 600 as shown as an example. In addition, the first air cooling unit 600 may have a plurality of heat dissipation fins 613 protruding from the inner surface forming the first cooling air flow path 610 to improve heat exchange efficiency, and the shape of the heat dissipation fin 613 and The arrangement may be formed in various ways. In addition, the first air cooling unit 600 may radiate heat to the outside by exposing the right side of the first air cooling unit 600 to the outside, and although not shown, heat dissipation fins may be formed on the surface that radiates heat to the outside. Also, in the first air cooling unit 600 , an opening 620 communicating with the first cooling air flow path 610 may be formed in a central portion corresponding to the rotation shaft 310 on a surface facing the rotation shaft 310 . In addition, heat dissipation fins may be formed on the inner surface of the motor housing 100 , the front bearing mounting part 110 , and the rear bearing mounting part 120 to improve heat exchange efficiency as shown.

The second air cooling unit 700 may include a cooling water flow path 710 and a second cooling air flow path 720 . The coolant flow path 710 may be formed to pass through the motor housing 100 . For example, the coolant flow path 710 may have a zigzag shape or a corrugated shape while going in the circumferential direction of the cylindrical body constituting the motor housing 100 . It may be formed in various shapes such as In addition, although not shown, a cooling water inlet and outlet connected to the cooling water flow path 710 may be formed in the motor housing 100 so that the cooling water may circulate along the cooling water flow path 710 , and the cooling water inlet and outlet are connected to an external cooling water pump and It can be connected to a coolant tank. In addition, the second cooling air flow path 720 may be formed at a position adjacent to the cooling water flow path 710 , and the second cooling air flow path 720 may be formed to pass through the motor housing 100 . In addition, the second cooling air flow path 720 may have one end connected to the outlet 612 of the first cooling air flow path 610 and the other end formed on the outer surface of the motor housing 100 .

The external return pipe 800 may be formed of various types of pipes, such as a pipe, a hose, and a flexible pipe, and the external return pipe 800 may be disposed outside the motor housing 100 and the impeller housing 410 . And the external return pipe 800 has one end connected to the other end of the second cooling air flow path 720 , and the external return pipe 800 has the other end connected to the inlet 411 which is the external air inlet side of the impeller housing 410 . can

Therefore, when the impeller 400 is rotated, some air from the air discharge side of the impeller 400 passes through the gap between the impeller 400 and the seal structure formed in the front bearing mounting part 110 of the motor housing 100. Part of the branched air may be introduced into the motor housing 100 through the front air foil journal bearing 510 , and the remaining air may be introduced into the motor housing 100 through the through hole 111 . And the air introduced into the motor housing 100 is branched after passing through the flow path between the stator 200 and the rotor 300 and between the teeth of the stator 200, and some air is in the rear air foil journal. After passing through the bearing 520 and the front air foil thrust bearing 530 in sequence, it flows into the space between the rear bearing mounting unit 120 and the first air cooling unit 600 , and some air passes through the diagonally formed through. After passing through the front air foil thrust bearing 530 sequentially through the ball 122 , it is introduced into the space between the rear bearing mounting unit 120 and the first air cooling unit 600 , and the remaining air passes through the through hole 121 . ) may be introduced into the space between the rear bearing mounting part 120 and the first air cooling part 600 . After that, the air is branched and some air passes through the rear air foil thrust bearing 540 and flows into the first cooling air passage 610 through the opening 620 of the first air cooling unit 600, and the remaining air is It may be introduced into the first cooling air flow path 610 through the inlet 611 of the first air cooling unit 600 . The air introduced into the first cooling air flow path 610 flows in the first cooling air flow path 610 and exchanges heat with the heat dissipation fins 613 to be cooled first, and then discharged through the outlet 612 to cool the second air. It is introduced into the second cooling air passage 720 of the unit 700 . Here, the air flow in the first cooling air flow path 610 of the first air cooling unit 600 may have an irregular flow, and a flow that rotates along the circumferential direction may be formed. A flow may be formed. The air introduced into the second air cooling unit 700 is cooled by heat exchange with the cooling water flowing along the cooling water flow path 710 located in the vicinity while following the second cooling air flow path 720 , and then cooled for the second time through the external return pipe 800 . ) through the inlet 411 of the impeller housing 410 may be introduced. At this time, as the air passing through the gap between the impeller 400 and the front bearing mounting part 110 of the motor housing 100 flows, the front air foil journal bearing 510 , the stator 200 , and the rotor 300 ) , it is possible to uniformly cool the rear airfoil journal bearing 520 , the front airfoil thrust bearing 530 , and the rear airfoil thrust bearing 540 . And the air heated by cooling the above components is first cooled by air cooling through heat radiation from the first air cooling unit 600 to the outside, and secondarily cooled by water cooling by cooling water in the second air cooling unit 700 . Afterwards, it is sent back to the inlet 411 of the impeller housing 410 . Accordingly, an increase in the temperature of the cooling air can be prevented, and the components can be cooled more efficiently.

In addition, a through hole 123 penetrating both surfaces may be additionally formed in the rear bearing mounting part 120 , and the through hole 123 may be formed not to communicate with the space in which the thrust runner 311 is disposed. have. In addition, an inlet 614 connecting the through hole 123 and the first cooling air flow path 610 may be additionally formed in the first air cooling unit 600 . Accordingly, a portion of the air inside the motor housing 100 may be directly introduced into the first air cooling unit 600 through the through hole 123 without passing through the air foil thrust bearings 530 and 540 .

<Example 2>

3 is a partial cross-sectional view showing an air compressor according to a second embodiment of the present invention.

As shown, the air compressor according to the second embodiment of the present invention has a configuration that differs from the first embodiment only in some forms of the first air cooling unit 600 . That is, the first air cooling unit 600 may be formed in a form in which the left side, which is the side facing the rotation shaft 310 , is blocked. Thus, the first air cooling unit 600 may introduce air into the first cooling air flow path 610 only through the inlet 611 .

<Example 3>

4 is a partial cross-sectional view showing an air compressor according to a third embodiment of the present invention.

As shown, the air compressor according to the third embodiment of the present invention has a configuration in which a diaphragm 630 is added to the first air cooling unit 600 in the first embodiment. The diaphragm 630 is provided in the first cooling air flow path 610 to form a flow path of air, and may serve to improve the heat exchange efficiency of air by the diaphragm 630 . The diaphragm 630 may be formed in the form of a relatively thin flat plate, for example, and the diaphragm 630 may be disposed to partition the first cooling air flow path 610 to the left and right. In addition, communication holes 631 penetrating both surfaces are formed in the diaphragm 630 so that air can pass through the communication holes 631 . In addition, the diaphragm 630 may be formed in various shapes and arrangements, and the communication hole 631 may be formed in one or more various numbers and positions.

<Example 4>

5 is a partial cross-sectional view showing an air compressor according to a fourth embodiment of the present invention.

As shown, the air compressor according to the fourth embodiment of the present invention has a configuration in which the diaphragm 630 is added to the first air cooling unit 600 in the second embodiment, and the diaphragm 630 is the third embodiment described above. It may be formed in the same manner as in the example.

The present invention is not limited to the above-described embodiments, and the scope of application is varied, and anyone with ordinary knowledge in the field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims It goes without saying that various modifications are possible.

100: motor housing
110: front bearing mounting part 111: through hole
120: rear bearing mounting portion 121: through hole
122: through hole 123: through hole
200: stator
300: rotor 310: rotation shaft
311: thrust runner 320: magnet
400: impeller 410: impeller housing
411: inlet 412: outlet
510: front airfoil journal bearing
520: rear airfoil journal bearing
530: front air foil thrust bearing
540: rear air foil thrust bearing
600: first air cooling unit 610: first cooling air flow path
611: entrance 612: exit
613: heat dissipation fin 614: inlet
620: opening
630: diaphragm 631: communication hole
700: second air cooling unit
710: cooling water flow path 720: second cooling air flow path
800: external return pipe

Claims (12)

a motor housing having a stator and a rotor therein, the rotor being rotatably coupled;
an impeller housing coupled to one side of the motor housing and communicating with the inside to form an inlet through which external air is introduced and an outlet through which air is discharged, and communicating with the inside of the motor housing;
an impeller provided inside the impeller housing and coupled to one end of the rotor;
First air coupled to the other side of the motor housing, a first cooling air flow path is formed therein, an inlet and an outlet communicating with the first cooling air flow path are formed, the inlet communicating with the inside of the motor housing cooling unit;
a cooling water passage passing through the motor housing and a second cooling air passage passing through the motor housing adjacent to the cooling water passage, wherein one end of the second cooling air passage is connected to an outlet of the first cooling air passage 2 air cooling unit; and
an external return pipe provided outside the motor housing and the impeller housing, one end connected to the second cooling air passage and the other end connected to the inlet of the impeller housing;
An air compressor comprising:
According to claim 1,
Air introduced into the motor housing through a gap between the impeller and the motor housing from the air discharge side of the impeller is heated by heat exchange with the stator and rotor while passing through the motor housing, and then to the first air cooling unit The air is firstly cooled by flowing in and radiating heat to the outside, then it passes through the second air cooling unit and is secondarily cooled by the cooling water, and then the air is introduced into the inlet side of the impeller housing through the external return pipe. Characterized by an air compressor.
According to claim 1,
The first air cooling unit,
An air compressor, characterized in that a plurality of heat dissipation fins are protruded from an inner surface forming the first cooling air flow path.
According to claim 1,
a pair of airfoil journal bearings coupled to bearing mounting portions formed on both sides of the motor housing, spaced apart from both sides of the rotor, and supporting a radial load so that the rotor is rotatable;
a thrust runner coupled to the other end of the rotor and disposed between the other bearing mounting part of the motor housing and the first air cooling part; and
a pair of air foil thrust bearings interposed between a bearing mounting portion adjacent to the thrust runner and the thrust runner and between the thrust runner and the first air cooling portion to support an axial load such that the thrust runner is rotatable;
Air compressor comprising a further.
5. The method of claim 4,
Air passing through a gap between the impeller and the motor housing on the air discharge side of the impeller is an air foil journal bearing disposed on one side, an air foil journal bearing disposed on the other side, between the stator and the rotor, and the pair of air foils An air compressor, characterized in that after passing through one or more air foil thrust bearings among the thrust bearings in sequence, the air is introduced into the first air cooling unit.
5. The method of claim 4,
Through-holes penetrating both surfaces are formed in the bearing mounting portions on both sides of the motor housing, and air passing through a gap between the impeller and the motor housing on the air discharge side of the impeller is an air foil journal bearing disposed on one side and a through-hole on one side is branched so as to pass through, and the air that has passed between the stator and the rotor is branched so as to pass through the air foil journal bearing disposed on the other side and the through hole of the other side.
7. The method according to any one of claims 4 to 6,
The first air cooling unit,
An opening penetrating the inside and the outside is formed in a central portion of a side facing the thrust runner, and the opening communicates with an air foil thrust bearing side disposed on the other side of the thrust runner.
7. The method according to any one of claims 4 to 6,
The first air cooling unit,
The air compressor, characterized in that formed in a form in which the side facing the thrust runner is closed.
8. The method of claim 7,
The first air cooling unit,
Air compressor, characterized in that provided with a diaphragm forming a flow path of air therein.
10. The method of claim 9,
The air compressor, characterized in that the diaphragm is formed with a communication hole passing through both surfaces.
9. The method of claim 8,
The first air cooling unit,
Air compressor, characterized in that provided with a diaphragm forming a flow path of air therein.
12. The method of claim 11,
The air compressor, characterized in that the diaphragm is formed with a communication hole passing through both surfaces.

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