Novel bearing cooling mode and air compressor with novel bearing cooling structure

Abstract

The invention discloses a novel bearing cooling mode and an air compressor with a novel bearing cooling structure, belongs to the field of air floatation air compressors, and overcomes the defect that a cooling air flow pipeline is additionally connected outside the air floatation air compressors. A first-step flow guide hole is formed in a first-stage side cover plate close to an air outlet area of a first-stage volute of the air compressor, and cooling air is guided into an internal air flow channel; when cooling is needed, the air flow channel is arranged, and cooling air flows through the surfaces of the air floatation thrust bearing and the two sets of radial bearings which need to be cooled and then is exhausted from the exhaust hole of the motor shell. The cooling device is suitable for cooling the interior of the air floatation air compressor which requires clean air and is good in sealing effect, and has good actual effects of improving the performance of the whole machine, reducing the product cost, facilitating use and maintenance and the like.

Description

Technical Field

[0001] The invention belongs to the field of air-floating air compressors, and in particular relates to an air compressor with a new bearing cooling method and structure. Background Art

[0002] At present, air bearing centrifugal air compressors are widely used in the automotive industry. Due to the requirements of the application scenario, the air outlet of the air compressor must be clean and oil-free. Therefore, air bearings are the best solution at present. However, since the working state of air bearings requires the motor rotor to rotate at high speed, this will cause the high-speed rotating parts inside the air compressor and its related parts to have high temperatures, which will cause damage to the parts, so cooling is needed. Although the current motor housing is equipped with a cold water pipe and an external cooling air flow duct, due to the cooling structure under the existing cooling method, such as Figure 1 As shown in the figure, it is a two-stage compression air compressor with an external cooling air duct. In order to cool the internal high-temperature components such as the air bearing, a path of gas is drawn from the air outlet area of ​​the first-stage volute as cooling air. Through the external cooling air duct, it is introduced into the gaps between the internal high-speed rotating components, flows through the surface of the high-temperature components such as the air bearing, and then discharges the internal heat-carrying gas through the exhaust holes on the motor housing. Figure 1 As shown, a hole is drilled in the middle air flow duct to install the joint, and a hole is also drilled in the motor housing of the air compressor to install the joint. The two joints are then connected with a customized high-temperature resistant rubber tube. At the same time, in order to ensure the airtightness requirements of automotive products, two customized clamps are needed to fix the rubber tube to the two joints. Such a structure will inevitably lead to increased processing costs and parts costs for production, and assembly and disassembly are relatively difficult. Summary of the Invention

[0003] The problem to be solved is: the current method of cooling the high-temperature components inside the air compressor by adding a cooling air flow duct outside the body and borrowing part of the exhaust air from the first-stage volute to be introduced into the interior of the air compressor has the problems of increased weight, difficult assembly and disassembly, high manufacturing cost, and difficulty in sealing due to the large number of components.

[0004] The new method of cooling the high-temperature components inside the air compressor disclosed in the present invention is: the cooling air still originates from the air outlet of the first-stage volute and flows out through the exhaust holes opened on the motor housing, but when the cooling air is introduced into the internal cooling of the high-temperature components, the air flow duct connected to the outside of the body is removed. The improved method is: the required cooling air flow channel is opened inside the air compressor, that is, the air guide, flow limiting and flow diversion structures are configured inside the air compressor, and with the help of the assembly gap between the components, a cooling air guide channel is formed together, allowing the cooling air to flow through the high-temperature components that need to be cooled, and then discharged from the exhaust holes opened on the motor housing, thereby bringing out the internal high-temperature heat, thereby achieving cooling, that is, the cooling air flow channel is configured to where cooling is needed.

[0005] The present invention discloses an air compressor with a new bearing cooling structure, including a set of impellers and volutes installed at both ends of the motor and its rotor. The air outlet of one volute is sealed in series with the air inlet of the other volute, thus forming a first-stage impeller, a first-stage volute, and a second-stage impeller, a second-stage volute. In other words, the air outlet of the first-stage volute is absorbed by the inlet of the second-stage volute. The bearing positions at both ends of the rotor are each supported by a set of air-floating radial bearings to limit the radial freedom of the rotor. The first-stage side of the rotor also uses an air-floating thrust bearing assembly to limit the axial freedom of the rotor. The present invention uses a set of air-floating thrust bearing assemblies and two sets of air-floating radial bearings to ensure that the high-speed rotating rotor will not rub against non-rotating parts in all directions. The air-floating thrust bearing assembly includes a thrust plate and air-floating thrust bearing sheets on both sides thereof; the axial limitation of the radial bearing and its bearing seat on the rotor is realized by the cover plates fixed on the motor housing at both ends of the motor rotor, namely the primary side cover plate and the secondary side cover plate; the air-floating thrust bearing sheet close to the primary side cover plate is the outer air-floating thrust bearing sheet, and the air-floating thrust bearing sheet close to the air-floating radial bearing is the inner air-floating thrust bearing sheet; when the motor rotates at high speed, the air-floating thrust bearing assembly on the primary side and the air-floating radial bearings at both ends of the motor jointly maintain the radial and axial air-floating rotation state of the rotor when it rotates at high speed; the air-floating thrust bearing assembly on the primary side and the air-floating radial bearings at both ends of the motor jointly maintain the radial and axial air-floating rotation state of the rotor when it rotates at high speed; the air-floating thrust bearing sheet used inside the air compressor The cooling air originates from the first-stage volute and is discharged through the exhaust holes on the motor housing. However, in the present invention, the cooling air flow channels are all opened inside the air compressor. Wherever cooling is needed, the cooling air channels are set there. In the present invention, the portion of the air diverted from the first-stage volute outlet is used as cooling air. The first-stage guide holes are opened on the first-stage side cover plate, radially located at the outer edge of the impeller. The air from the first-stage volute is guided through the first-stage guide holes and directed into the inner side of the first-stage side cover plate, from where it enters the assembly gap, guide hole, or storage and rotation gap of the high-speed rotating high-temperature components inside the air compressor. This is the purpose of the present invention, which replaces the design structure of the existing technology of adding cooling air flow ducts to the outside.

[0006] Preferably, the cooling air from the first-stage air guide hole is directed to the chamber inside the first-stage side cover plate where the air-floating thrust bearing assembly is installed. That is, the first-stage air guide hole on the first-stage side cover plate is connected to the chamber where the air-floating thrust bearing assembly is installed. The cooling air then spreads from the thrust bearing chamber to the connected assembly gap and is eventually discharged toward the exhaust hole on the motor housing. During the flow of this cooling air, the assembly gaps between the two sides of the thrust bearing assembly, the rotor, the radial bearing, and its bearing seat are involved. The surfaces of the thrust bearing, the radial bearing, and its associated bearing seat, as well as the temperatures of the rotor's affected surfaces, can all be cooled.

[0007] Furthermore, in order to strengthen the cooling of the outer air-floating thrust bearing plate, guide holes are opened in the first-level side cover plate and on the first-level radial bearing seat from the radial root near the thrust plate to guide the cooling air flow into the cavity of the motor housing. That is, after the cooling air flows through the outer thrust bearing, it flows to the exhaust hole on the motor housing for discharge; specifically, 6 guide holes are preferably provided to form 6 cooling air guide channels for cooling the outer thrust bearing assembly.

[0008] Furthermore, a cooling air guide channel is opened to the secondary radial bearing. In the present invention, the air flow channel passes through the primary side cover, the primary radial bearing seat, the motor housing, the secondary radial bearing seat, and the secondary side cover. Finally, the cooling air enters the axial outer side of the secondary radial bearing, and then flows out along the assembly gap between the rotor and the radial bearing, and the gap between the stator and the rotor, toward the exhaust hole on the motor housing; preferably, an air flow transfer chamber is left between the secondary side cover and the secondary radial bearing and its bearing seat, so that the air flow introduced into the secondary side bearing is evenly sent to the assembly gap, thereby obtaining a uniform cooling air flow.

[0009] Preferably, all the guide channels in the present invention share the first-step guide hole; then an air flow distribution center is arranged on the inner side of the first-stage side cover plate, and the first-step guide hole is connected to the air flow distribution center, so that the cooling air flow separated from the first-stage volute is introduced into the air flow distribution center after passing through the first-step guide hole, and then sent to the air flow channels corresponding to the various high-temperature components that need to be cooled inside the air compressor.

[0010] Specifically, the air flow distribution center is based on the inner side of the primary side cover plate, and the chamber for installing the thrust bearing is redesigned so that the inner side of the primary side cover plate has a flow limiting boss and a ventilation groove to achieve limited flow diversion, and there are also diversion holes and a diversion bay to achieve cooling of the secondary side; preferably, the air flow distribution center has a diversion bay for cooling the secondary side radial bearing, a flow limiting boss and several ventilation grooves thereof, a thrust bearing chamber, and an air flow channel formed by a flow guide hole for cooling the outer thrust bearing.

[0011] Preferably, the cover plate on the primary side has three oblique first-stage flow guide holes, a diversion bay, a flow limiting boss and six ventilation grooves connected to the thrust bearing chamber, and six flow guide holes for cooling the outer thrust bearing.

[0012] Preferably, a cooling water channel is provided on the motor housing of the present invention to reduce the high temperature inside the motor. Therefore, when the cooling air flows through the motor housing, the air outlet of the first-stage volute can be cooled and then enter the gap around the air-floating radial bearing on the secondary side, thereby achieving a better cooling effect.

[0013] Through the above series of feasible technical solutions, it is known that after a number of cooling air flow channels are set up inside, there is no need for external cooling air guide ducts, which well solves the problems in the existing technology. The advantages are that it is easy to meet the sealing requirements and easy to obtain clean cooling air that meets the requirements. After reducing the added parts, the weight of the whole machine is reduced and it is convenient for transportation, assembly and disassembly, which greatly facilitates manufacturing and reduces manufacturing costs. Most importantly, the cooling range can be wider, the cooling effect can be better, and the cooling air utilization efficiency is also high. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 , Schematic diagram of the appearance of the old external cooling air duct Figure 2 , schematic diagram of the air compressor with new bearing cooling structure Figure 3 , structural display diagram of the first-level side cover Figure 4 , Schematic diagram of the air flow channel for cooling the first-stage radial bearing Figure 5 , Schematic diagram of the air flow channel for cooling the outer side of the thrust bearing assembly Figure 6 , Schematic diagram of the air flow channel for cooling the secondary radial bearing Figure 7 , structural display diagram of the first-level radial bearing seat Figure 8 , structural display diagram of the secondary radial bearing seat The names corresponding to the marks in the above figures are as follows: 1st stage volute; 2 first-stage impeller; 3. First level side cover; 3.1 The first step is the diversion hole; 3.2 Current limiting boss 3.3 Ventilation groove (on the flow limiting boss); 3.5 Diversion bay (used for diversion when cooling the secondary side bearing); 4. First-level radial bearing seat; 5. Motor rotor; 6. Motor housing; 7. Secondary radial bearing seat; 8. Secondary side cover; 9 two-stage impeller; 10 secondary volute; 11. First-level radial bearing; 12 secondary radial bearings 13 thrust bearing assembly a. First-stage volute air inlet; b. First-stage volute air outlet area; c air flow distribution center; d. Chamber for installing thrust bearing; e. Diversion holes for cooling the outer thrust bearing (6 holes are opened on the first-stage side cover); f. Guide holes for cooling the outer thrust bearing (six holes are provided on the first-stage radial bearing seat); g. A guide hole for cooling the secondary radial bearing (one opened on the primary radial bearing seat); h motor cavity; i. Guide hole for cooling the secondary radial bearing (one on the secondary radial bearing seat) j Cooling air storage and transfer chamber on the secondary side; k guide hole for cooling the secondary radial bearing (a channel opened on the motor housing); mFirst-stage radial bearing clearance (with the rotor); nSecondary radial bearing clearance (with rotor) o Exhaust holes on the motor housing P Cooling water pipe Specific embodiments

[0015] This embodiment discloses an air compressor with a new bearing cooling structure, such as Figure 2 The schematic diagram of the whole machine structure shown includes a set of impellers and volutes installed at both ends of the motor and its rotor 5, wherein the air outlet of one volute is sealed in series with the air inlet of the other volute, thus forming a first-stage volute 1, a first-stage impeller 2 and a second-stage impeller 9, a second-stage volute 10. That is, the air outlet of the first-stage volute 1 is absorbed by the inlet of the second-stage volute 10; a set of air-floating radial bearings is used at the bearing positions at both ends of the rotor 5 to limit the radial freedom of the rotor 5; an air-floating thrust bearing assembly 13 is also configured on the first-stage side to limit the axial freedom of the rotor 5. It can be seen that the air-suspended rotation support of the entire rotor 5 is achieved by two sets of air-floating radial bearings (11, 12) and a set of air-floating thrust bearing assembly 13, ensuring that the rotor 5 will not rub against the non-rotating parts in all directions when rotating at high speed. The air-floating thrust bearing assembly 13 includes a thrust plate and air-floating thrust bearing plates on both sides thereof; the axial limitation of the bearing seat 4 of the first-stage radial bearing 11 and the bearing seat 7 of the second-stage radial bearing 12 on the rotor 5 is achieved by a cover plate coaxially mounted and fixed to the end of the motor housing 6, i.e. Figure 2 The first-level side cover plate 3 and the second-level side cover plate 8.

[0016] In this embodiment, Figure 2As shown by the dotted lines and arrows at the marks IN and OUT in the figure, the cooling air used to cool the interior of the air compressor is separated from the outlet air of the first-stage volute 1 and returned to the exhaust hole O provided on the motor housing 6. The cooling air carrying the heat from the internal of the air compressor is discharged from the motor cavity h. In particular, the air flow channels for the cooling air are all implemented from the inside. Where cooling is needed, the cooling air channels are set there, thereby replacing the previous design structure of adding cooling air air flow ducts externally.

[0017] like Figure 3 The figure shows the design structure of the first-stage side cover 3. The first-stage guide hole 3.1 for cooling air is opened on the first-stage side cover 3. Figure 2 As can be seen, the air outlet area b of the first-stage volute 1 located at the radial outer edge of the first-stage impeller 2, through the first-stage guide hole 3.1, takes part of the air outlet of the first-stage volute as cooling air and introduces it into the inner side of the first-stage side cover 3; in this embodiment, all air flow channels share the first-stage guide hole 3.1, and then an air flow distribution center c is arranged on the inner side of the first-stage side cover 3, so that the cooling air separated from the air outlet of the first-stage volute 1 is introduced into the air flow distribution center c and then sent to the surfaces of various high-temperature components that need to be cooled inside the air compressor; the air flow distribution center c is based on the axial inner side of the first-stage side cover 3, and the chamber d for installing the thrust bearing is redesigned so that the inner side of the first-stage side cover 3 has a flow limiting boss 3.2 and a ventilation groove 3.3 to achieve limited flow diversion. In addition, there is a guide hole e for cooling the outer thrust bearing and a diversion bay 3.5 leading to the secondary bearing, as shown Figure 2 and Figure 3 As shown, the gaps and spaces between the primary side cover 3 and the adjacent components in the whole machine are formed as follows: Figure 4 、 Figure 5 、 Figure 6 Three different cooling air flow paths are shown: like Figure 4 , is a schematic diagram of the airflow path for cooling the first-stage radial bearing 11. As can be seen from this figure, the cooling air from the first-stage volute 1 enters the airflow distribution center c through the first-step guide hole 3.1, flows through the inner side of the air-floating thrust bearing assembly 13, the assembly gap m between the first-stage radial bearing 11 and its bearing seat 4, then enters the motor cavity h, and is finally discharged through the exhaust hole O in the motor housing 6. This airflow path cools both the inner side of the air-floating thrust bearing assembly 13 and the first-stage radial bearing 11.

[0018] like Figure 5, is a schematic diagram of the air flow channel for cooling the outer side of the air-floating thrust bearing assembly 13. As can be seen from the figure, the cooling air entering the air flow distribution center c flows through the outer side of the air-floating thrust bearing assembly 13, then passes through the guide hole e on the first-level side cover plate 3 and the guide hole f on the first-level radial bearing seat 4, and then enters the motor cavity h, and is finally discharged from the exhaust hole O of the motor housing 6, mainly taking away the heat on the outer side of the air-floating thrust bearing assembly 13.

[0019] like Figure 6 , which is a schematic diagram of the air flow channel mainly for cooling the secondary radial bearing 12. The air flow channel passes through the diversion bay 3.5 on the primary side cover 3, the guide hole g on the primary radial bearing seat 4, the guide hole k on the motor housing 6, and the guide hole i on the secondary radial bearing seat 7, and then reaches the secondary side air flow storage chamber j formed by the secondary side cover 8, the secondary radial bearing 12 and its bearing seat 7. At this point, the cooling wind will naturally move toward the exhaust hole O of the motor housing 6, and will flow out toward the exhaust hole O along the assembly gap n between the secondary radial bearing 12 and the rotor 5, and the gap between the rotor and the inner surface of the stator, thereby taking away the heat from the motor rotor 5 and the inner surface of the stator. Since the motor housing 6 in this embodiment is provided with the following Figure 2 As shown above, the cooling water pipe P, when the cooling air flows through the motor housing 6, the air outlet of the first-stage volute 1 can be cooled before entering the air-floating radial bearing on the second-stage side.

[0020] This embodiment is specially designed according to the specific conditions of the actual air compressor structure. The internal and axial inner structures of the first-stage side cover plate 3 are as follows: Figure 2 and 3 As shown, the first step guide hole 3.1 is an oblique hole, so that the air outlet of the first stage volute 1 can be obliquely entered into an air flow distribution center c; in the air flow distribution center c, a diversion bay 3.5 and a flow limiting boss 3.2 with a vent groove 3.3 are also provided to prevent the air flow from directly entering the distribution center after entering the distribution center. Figure 4 and Figure 5 airflow channels, leading to Figure 6 The cooling air flow rate obtained by the air flow channel is too small; the diversion bay 3.5 is set to open a cooling channel leading to the secondary bearing side; the ventilation groove 3.3 of the flow-limiting boss 3.2 is connected to the chamber d where the thrust bearing is installed; the cooling air enters the thrust plate chamber through the ventilation groove 3.3 of the flow-limiting boss 3.2 to help cool the air-floating thrust bearing and the air-floating radial bearing.

[0021] In this embodiment, Figure 3 As shown, the first-stage side cover plate 3 is evenly distributed on the radial circumference with three first-stage guide holes 3.1 for guiding the cooling air from the first-stage volute 1 into the air flow distribution center c of the first-stage side cover plate 3; Figure 4 and Figure 3As shown, it can be seen that in this embodiment, six ventilation slots 3.3 are provided on the flow limiting boss 3.2 of the air flow distribution center c of the first-stage side cover plate 3 to allow cooling air to enter the chamber d where the thrust bearing is installed, and the cooling air entering the inner side of the thrust bearing is as shown in FIG. Figure 4 As shown, it will naturally enter the assembly gap between the rotor 5 and the primary side radial bearing and its bearing seat, and after entering the motor cavity h, it will finally be discharged through the exhaust hole O on the motor housing 6; Figure 5 The air flow channel is provided with 6 guide holes on the first-level side cover 3, such as Figure 7 As shown, the corresponding primary side bearing seat also has 6 guide holes f, which together guide the cooling air from the air flow distribution center c into the motor cavity h, thus achieving good cooling of the outer side of the air-floating thrust bearing assembly 13; In addition, this embodiment only has one air flow channel leading to the secondary radial bearing 12, as shown in FIG. Figure 6 and 8 As shown, a guide hole i is opened on the secondary radial bearing seat 7, and an air flow storage chamber j on the secondary side is specially reserved to receive the cooling air coming from the guide hole i; the air flow storage chamber j on the secondary side is surrounded by the secondary side cover plate 8, the radial bearing and its bearing seat 7, so as to facilitate the uniform introduction of the cooling air into the assembly gap between the secondary radial bearing 12 and the rotor 5 in a circumferential manner; in this embodiment, due to the opening of the exhaust hole O on the motor housing 6, the cooling air will naturally be discharged in the direction of the exhaust hole O along the assembly gaps of the motor rotor 5, the secondary radial bearing 12 and its bearing seat 7 and the motor housing 6.

[0022] From the above embodiments, it can be seen that the several internal cooling air flow channels in the present invention are intended to improve the defects of the previous external cooling air guide ducts of the air compressor. Instead, the cooling air from the same source is used in a simpler, faster, more efficient and low-cost manner to achieve more satisfactory results.

[0023] The present invention proposes a cooling structure for an air compressor, which structurally eliminates the intermediate cooling air flow pipe connected to the outside of the body and instead opens a cooling air flow channel inside the air compressor body to achieve cooling of high-speed rotating high-temperature components such as air-floating bearings inside the air compressor; the technical solutions of the present invention are formed by cutting during manufacturing, are easy to manufacture, do not require additional parts, and are light in weight, thereby avoiding a series of problems existing in the prior art, including a reduction in the number of parts, simplified assembly and disassembly, easy access to clean air, easy internal sealing, reduced size of the air compressor, more conducive to user layout and installation, and reduced procurement and management costs. The air compressor with the new bearing cooling structure of the present invention also greatly reduces the air supply cost for cooling the bearings of the air-floating bearing centrifugal air compressor, shortening the production cycle and cost.

[0024] Compared with the cooling air guide duct added to the outside of the air compressor in the prior art, the idea of ​​the present invention is that although the starting point and end point of the cooling air flow channel remain unchanged, the intermediate link of the cooling air flow channel is to configure a flow-guiding, flow-limiting and / or flow-diverting structure inside the air compressor, and utilize the assembly gap to jointly form a cooling air guide channel, intentionally allowing the cooling air to flow through various surfaces that need to be cooled to achieve cooling of high-temperature components. In order to cool the internal high-temperature components, no matter what improvements are made to the internal structure, as long as the idea of ​​the present invention is followed, there may be better solutions, which should all fall within the scope of protection of the present invention. The design concept of the present invention is not limited to the products involved in the present invention, but is also suitable for the setting design of fluid cooling channels on other occasions and other products.

Claims

1. The new bearing cooling method of the air compressor, the cooling air used is still borrowed from the first-stage volute air outlet, and flows out from the exhaust hole opened on the motor housing. The characteristics are: The new method is to remove the cooling air flow duct connected to the outside of the body, and instead open the required air flow channel inside the air compressor, and configure the flow diversion, flow limiting and flow diversion structures inside the air compressor, and use the assembly gap to form a cooling air diversion channel to allow the cooling air to flow through the high-temperature components that need to be cooled, thereby achieving the cooling purpose; wherever cooling is needed, the cooling air flow channel will be directed there.

2. A new bearing cooling structure for an air compressor, comprising a set of impellers and volutes installed at both ends of a motor and its rotor, wherein the air outlet of one volute is sealed in series with the air inlet of the other volute, so that when the whole machine is in operation, a first-stage impeller, a first-stage volute and a second-stage impeller, a second-stage volute are formed, i.e., the air outlet of the first-stage volute is absorbed by the air inlet of the second-stage volute; a set of air-floating radial bearings and their bearing seats are used at the bearing positions at both ends of the rotor to limit the radial freedom of the rotor; an air-floating thrust bearing assembly is also used on the first-stage side of the rotor to limit the axial freedom of the rotor; through two sets of air-floating radial bearings, the rotor is cooled and cooled, and the air flow is continuously cooled. The bearing and a set of air-floating thrust bearing assemblies ensure that the rotor will not rub against the non-rotating parts in all directions when rotating at high speed; the air-floating thrust bearing assembly includes a thrust plate and air-floating thrust bearing plates on both sides thereof; the axial limitation of the radial bearing seat on the rotor is achieved by the cover plates fixed on the motor housing at both ends of the motor rotor, so there are first-stage side cover plates and second-stage side cover plates; the cooling air used inside the air compressor comes from the outlet of the first-stage volute and flows out of the exhaust hole opened on the motor housing; the air compressor with the new bearing cooling structure is characterized in that, The air flow channels for cooling air are all opened inside the air compressor. The cooling air channels are set up wherever cooling is needed. The air outlet from the first-stage volute is diverted as cooling air. The first-step guide hole of the cooling air flow channel is opened on the first-stage side cover plate. The first-stage volute air outlet area is radially located at the outer edge of the first-stage impeller. Part of the air outlet from the first-stage volute is introduced into the inner side of the first-stage side cover plate through the first-step guide hole, and then enters the assembly gap or storage space and guide channel inside the air compressor.

3. The air compressor with the new bearing cooling structure according to claim 2 is characterized in that: The cooling air coming out of the first-stage guide hole is guided to the chamber where the thrust bearing assembly is installed on the inner side of the first-stage side cover. That is, the first-stage guide hole on the first-stage side cover is connected to the chamber where the thrust bearing assembly is installed, so that the cooling air spreads from the thrust bearing chamber to the communicating assembly gap and is discharged toward the exhaust hole on the motor housing.

4. The air compressor with the new bearing cooling structure according to claim 3 is characterized in that: In order to enhance the cooling of the outer side of the air-floating thrust bearing assembly, that is, the high-temperature surface of the air-floating thrust bearing assembly near the first-stage side cover plate, guide holes are respectively opened on the first-stage side cover plate and the first-stage radial bearing seat from the radial root near the air-floating thrust bearing assembly to guide the cooling air into the cavity of the motor housing and then move toward the exhaust hole on the motor housing and be discharged.

5. The air compressor with the new bearing cooling structure as described in claim 4 is equipped with 6 internal air flow channels for cooling the outer thrust bearing assembly, that is, there are 6 guide holes opened on the first-level side cover plate and corresponding 6 guide holes opened on the first-level bearing seat.

6. The air compressor with a new bearing cooling structure according to claim 1 is characterized in that: The cooling air guide channel is opened to the secondary radial bearing. The air flow channel passes through the primary side cover, the primary radial bearing seat, the motor housing, and the secondary radial bearing seat. The cooling air is then introduced into an air flow transfer chamber left between the secondary side cover and the secondary radial bearing and its bearing seat, evenly contacts the end of the secondary radial bearing, and then flows along the assembly gap of the components towards the exhaust hole on the motor housing.

7. An air compressor with a new bearing cooling structure according to any one of claims 2 to 6, characterized in that: All air flow channels share the first-stage guide hole, and an air flow distribution center is arranged on the inner side of the first-stage side cover plate, so that the cooling air flow separated from the first-stage volute passes through the first-stage guide hole and is introduced into the air flow distribution center, and then sent to the corresponding air flow channels inside the air compressor, and finally rushes to the exhaust hole on the motor casing.

8. The air compressor with the new bearing cooling structure according to claim 7 is characterized in that: The air flow distribution center is a redesign of the inner side of the chamber where the thrust bearing is installed on the first-stage side cover plate, so that the inner side of the first-stage side cover plate has a flow-limiting boss and a ventilation groove to achieve limited flow into the thrust bearing chamber. In addition, diversion holes and diversion bays are designed to meet the cooling needs of the outer side of the second-stage radial bearing and the air-floating thrust bearing assembly.

9. The air compressor with the new bearing cooling structure according to claim 8, characterized in that: On the cover plate on the first-stage side, there are three oblique first-step guide holes, a diversion bay, a flow-limiting boss and six ventilation grooves connected to the thrust bearing chamber, and six guide holes for cooling the outer air-floating thrust bearing assembly; a cooling air storage chamber is specially set between the second-stage cover plate and the second-stage radial bearing and bearing seat to receive the cooling air from the guide hole on the second-stage bearing seat, and to allow the cooling air to move from the storage chamber to the exhaust hole on the motor housing. In the middle, the cooling air flows through the assembly gap between the motor rotor and the inner surface of the stator.

10. The air compressor with the new bearing cooling structure according to claim 9, characterized in that: The motor housing is equipped with a cooling water channel to reduce the high temperature inside the motor. Therefore, when the cooling air flows through the motor housing, the air outlet of the first-stage volute can be cooled before entering the guide holes and assembly gaps on the secondary side bearing seat.

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