A dual-pole compressor

Abstract

The application discloses a kind of bipolar compressor, including primary volute and primary impeller located in it, secondary volute and secondary impeller located in it and shell and rotor located in it, thrust bearing seat is equipped with the thrust bearing chamber for accommodating thrust bearing between shell;Wherein, secondary pull rod is equipped with secondary pull rod air passage, the gas outlet of primary volute is communicated with secondary pull rod air passage by interstage cooling system, rotor is equipped with rotor air passage, secondary impeller is equipped with secondary impeller air passage, the end of shell close to thrust bearing seat is equipped with shell end air passage with the inner cavity of shell is communicated, secondary pull rod air passage, rotor air passage, secondary impeller air passage, thrust bearing chamber and shell end air passage are sequentially communicated to form thrust bearing cooling channel.This application introduces low-temperature gas at secondary turbine air inlet to cool thrust bearing, enhances the cooling effect of thrust bearing, and does not need to introduce water cooling channel additionally, so that overall structure is more compact and safety reliability is higher.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressors, and more particularly to a bipolar compressor. BACKGROUND

[0002] The bipolar compressor has a thrust bearing which is sleeved on the rotor to bear the axial thrust of the rotor in operation, however, the thrust bearing will generate a large amount of heat under high-speed working conditions, and the thrust bearing with excessively high temperature will fail, affecting the normal operation of the bipolar compressor.

[0003] The existing bipolar compressor usually adopts a combination of water cooling and air cooling to cool the thrust bearing, however, the combination of air cooling and water cooling for cooling design requires an additional cooling channel to be introduced, resulting in a low overall structure, and the water cooling channel has a risk of leakage and low safety and reliability; in addition, the compressor itself is usually used to suck air at normal temperature, so that the air flowing into the inner cavity of the base flows through the thrust bearing to cool the thrust bearing, but the air cooling is only an auxiliary cooling means, and the cooling effect on the thrust bearing is general.

[0004] In summary, how to provide a bipolar compressor which only utilizes air cooling to enhance the cooling effect of the thrust bearing is a problem to be solved by the technical personnel in the field at present. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a bipolar compressor which cools the thrust bearing by using the gas of the secondary volute inlet to enhance the cooling effect of the thrust bearing and improve the compactness and safety and reliability of the structure.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0007] A bipolar compressor comprises a primary volute and a primary impeller located in the primary volute, a secondary volute and a secondary impeller located in the secondary volute, and a casing and a rotor located in the casing, the primary impeller is connected with a first output end of the rotor, the secondary impeller is connected with a second output end of the rotor through a secondary pull rod, a thrust bearing seat is sealingly arranged between the secondary volute and the secondary impeller, and a thrust bearing chamber for accommodating a thrust bearing is arranged between the thrust bearing seat and the casing;

[0008] The secondary pull rod is provided with a secondary pull rod air channel, the gas outlet of the primary volute is communicated with the secondary pull rod air channel through an inter-stage cooling system, the rotor is provided with a rotor air channel, the secondary impeller is provided with a secondary impeller air channel, one end of the casing close to the thrust bearing seat is provided with a casing end air channel which is communicated with the inner cavity of the casing, and the secondary pull rod air channel, the rotor air channel, the secondary impeller air channel, the thrust bearing chamber and the casing end air channel are sequentially communicated to form a thrust bearing cooling channel.

[0009] Preferably, the primary volute and the casing are provided with the fan volute, the fan volute is provided with the fan sleeved on the rotor, the peripheral wall of the fan volute is provided with a fan volute air outlet for communicating the inner cavity and the outside, the peripheral wall of the casing is provided with a casing air inlet for communicating the outside and the inner cavity, and the end of the casing close to the fan volute is provided with a fan volute air inlet communicating with the inner cavity of the fan volute.

[0010] The casing air inlet, the inner cavity of the casing, the fan volute air inlet, the inner cavity of the fan volute and the fan volute air outlet are sequentially communicated to form a stator cooling channel.

[0011] Preferably, the casing is provided with the stator arranged around the rotor, and the one side of the stator and the rotor are left with a stator-rotor gap, and the other side of the stator is connected with the inner wall of the casing through the connecting plate, the connecting plate divides the inner cavity of the casing into a left inner cavity and a right inner cavity, and the connecting plate is provided with an auxiliary air passage.

[0012] The stator cooling channel includes a first branch channel and a second branch channel, the first branch channel is sequentially communicated by the casing air inlet, the right inner cavity, the stator-rotor gap, the fan volute air inlet, the inner cavity of the fan volute and the fan volute air outlet, and the second branch channel is sequentially communicated by the casing air inlet, the auxiliary air passage, the left inner cavity, the fan volute air inlet, the inner cavity of the fan volute and the fan volute air outlet.

[0013] Preferably, the end of the casing close to the fan volute and the rotor are provided with a first bearing chamber for accommodating the first radial bearing, and the inner cavity of the casing, the first bearing chamber, the inner cavity of the fan volute and the fan volute air outlet are sequentially communicated to form a first radial bearing cooling channel.

[0014] Preferably, the end of the casing close to the thrust bearing seat and the rotor are provided with a second bearing chamber for accommodating the second radial bearing, and the thrust bearing chamber, the second bearing chamber and the inner cavity of the casing are sequentially communicated to form a second radial bearing cooling channel.

[0015] Preferably, the thrust bearing seat is provided with a sealing disc groove communicating with the thrust bearing chamber, and the sealing disc groove is provided with a sealing disc and sealingly connected with the outer ring of the sealing disc, and the inner ring of the sealing disc is sealingly connected with the outer periphery of the secondary impeller.

[0016] Preferably, a bearing groove shaped to the thrust bearing is arranged between the opposite end faces of the casing and the thrust bearing seat, the thrust bearing seat is distanced from the bearing groove by a plurality of casing end grooves from near to far, the thrust bearing seat is distanced from the bearing groove by a plurality of bearing seat grooves from near to far, the plurality of bearing seat grooves, the bearing groove and the plurality of casing end grooves are sequentially communicated to form the thrust bearing chamber.

[0017] Preferably, a part of the secondary pull rod passes through the secondary impeller to connect the second end of the rotor, and another part of the secondary pull rod is arranged outside the secondary impeller and is provided with an airflow adjusting member for adjusting the airflow in the secondary pull rod air channel.

[0018] Preferably, the airflow adjusting member comprises an adjusting rod and an adjusting block, the adjusting rod is movably inserted into the sidewall of the secondary pull rod, and the insertion part of the adjusting rod is connected to the adjusting block located in the secondary pull rod air channel to drive the adjusting block to move and adjust the size of the cross section of the secondary pull rod air channel blocked by the adjusting block.

[0019] Compared with the prior art, the bipolar compressor provided by the application can quickly rotate the primary impeller to compress the gas in the primary volute into high-pressure gas under the action of the fast rotation of the primary impeller. The temperature of the gas after the initial compression is relatively high. After being cooled to a specified temperature by the inter-stage cooling system, the low-temperature and high-pressure gas flows into the secondary pull rod air channel through the secondary turbine inlet, and then flows into the inner cavity of the casing along the thrust bearing cooling channel. In this process, the low-temperature and high-pressure gas passes through the thrust bearing chamber, effectively cooling the thrust bearing. Therefore, the low-temperature gas at the secondary turbine inlet is introduced to cool the thrust bearing, which enhances the cooling effect of the thrust bearing, and no additional water cooling channel is needed, so that the overall structure is more compact, and the risk of water leakage does not need to be considered, which is safer and more reliable. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of the provided drawings.

[0021] Figure 1 It is an axial sectional view of the bipolar compressor provided by the application.

[0022] Figure 2 It is a schematic view of the thrust bearing cooling channel provided by the application.

[0023] Reference signs:

[0024] 1-motor; 10-housing; 11-rotor; 12-stator; 13-housing end air passage; 14-housing air inlet; 15-fan volute air inlet; 16-first bearing chamber; 17-second bearing chamber; 18-connection plate; 19-assistant air passage; 101-housing; 102-first stage end cover; 103-second stage end cover; 171-housing end groove; 172-bearing seat groove; 173-bearing groove;

[0025] 2-first stage compressor; 20-first stage volute; 21-first stage impeller; 22-first stage tie rod; 23-fan volute; 24-fan; 25-fan volute air outlet;

[0026] 3-second stage compressor; 30-second stage volute; 31-second stage impeller; 32-second stage tie rod; 33-thrust bearing seat; 34-second stage tie rod air passage; 35-rotor air passage; 36-second stage impeller air passage; 37-thrust bearing chamber; 38-seal disc; 39-thrust disc;

[0027] 4-inter-stage cooling system;

[0028] A-thrust bearing cooling passage; B-stator cooling passage; B1-first branch passage; B2-second branch passage; C-first radial bearing cooling passage; D-second radial bearing cooling passage. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0030] The core of the present application is to provide a dual-pole compressor, which cools the thrust bearing by using the gas of the second stage volute air inlet, so as to enhance the cooling effect of the thrust bearing, and improve the compactness and safety and reliability of the structure.

[0031] It should be noted that in the present embodiment, the directions or positional relationships indicated by "upper", "lower", "front", "rear" and the like are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0032] Please refer to Figure 1 and Figure 2The application provides a bipolar compressor, which comprises a first-stage volute, a first-stage impeller located in the first-stage volute, a second-stage volute, a second-stage impeller located in the second-stage volute, a casing and a rotor located in the casing, the first-stage impeller is connected with a first output end of the rotor, the second-stage impeller is connected with a second output end of the rotor through a second-stage pull rod, a thrust bearing seat is sealingly arranged between the second-stage volute and the second-stage impeller, and a thrust bearing chamber for accommodating a thrust bearing is arranged between the thrust bearing seat and the casing.

[0033] The second-stage pull rod is internally provided with a second-stage pull rod air channel, an air outlet of the first-stage volute is in communication with the second-stage pull rod air channel through an inter-stage cooling system, the rotor is provided with a rotor air channel, the second-stage impeller is provided with a second-stage impeller air channel, an end of the casing close to the thrust bearing seat is provided with a casing end air channel in communication with an inner cavity of the casing, and the second-stage pull rod air channel, the rotor air channel, the second-stage impeller air channel, the thrust bearing chamber and the casing end air channel are sequentially communicated to form a thrust bearing cooling channel.

[0034] Specifically, the bipolar compressor usually comprises a motor 1, a first-stage compressor 2 and a second-stage compressor 3, the motor 1 comprises a casing 10 and a rotor 11, the rotor 11 is rotatably arranged in the casing 10 and two output ends of the rotor 11 respectively extend out of two ends of the casing 10, wherein an end of the rotor 11 close to a thrust bearing seat 33 is a second output end of the rotor 11, and an end of the rotor 11 close to a fan volute 33 is a first output end of the rotor 11; the first-stage compressor 2 comprises a first-stage volute 20 arranged at a first end of the casing 10 and a first-stage impeller 21 located in the first-stage volute 20 and connected with the first output end of the rotor 11, for initially compressing gas; the second-stage compressor 3 comprises a second-stage volute 30, a second-stage impeller 31, a second-stage pull rod 32 and the thrust bearing seat 33, the second-stage volute 30 is arranged at a second end of the casing 10, the second-stage impeller 31 is located in the second-stage volute 30 and connected with the second output end of the rotor 11 through the second-stage pull rod 32, the thrust bearing seat 33 is arranged on the second end of the casing 10, an outer ring of the thrust bearing seat 33 is sealingly matched with an inner wall of the second-stage volute 30, an outer periphery of the second-stage impeller 31 is sealingly matched with one side of an inner ring of the thrust bearing seat 33, and a thrust bearing chamber 37 for accommodating a thrust bearing is arranged between the other side of the inner ring of the thrust bearing seat 33 and the second end of the casing 10.

[0035] It should be noted that the casing 10 comprises a shell 101 and a first end cover 102 and a second end cover 103 respectively arranged at both ends of the shell 101, the first end of the casing 10 is the first end cover 102, the second end of the casing 10 is the second end cover 103, the first output end of the rotor 11 is rotatably connected with the first end cover 102 through the first radial bearing, the second output end of the rotor 11 is rotatably connected with the second end cover 103 through the second radial bearing, the first volute 20 and the second volute 30 are respectively installed on the first end cover 102 and the second end cover 103, and the first volute 20 and the second volute 30 both have an air inlet and an air outlet, the inter-stage cooling system 4 is arranged between the air outlet of the first volute 20 and the air inlet of the second volute 30, which is usually composed of a conveying pipeline and a cooler arranged on the conveying pipeline, thus, the normal temperature and pressure gas enters the inner cavity of the first volute 20 through the air inlet of the first volute 20, the rotor 11 rotates to drive the first impeller 21 to rotate rapidly, which can initially compress the gas in the first volute 20 into high-temperature and high-pressure gas, the high-temperature and high-pressure gas flows into the conveying pipeline and is cooled to low-temperature and high-pressure gas by the cooler, and then flows into the inner cavity of the second volute 30 through the air inlet of the second volute 30, the rotor 11 rotates to drive the second impeller 31 to rotate rapidly, which can re-compress the low-temperature and high-pressure gas to the required pressure level. In addition, part of the low-temperature and high-pressure gas flows into the second pull rod gas channel 34 in the second pull rod 32, and then flows into the thrust bearing chamber 37 through the rotor gas channel 35 and the second impeller gas channel 36 in sequence to cool the thrust bearing, and finally the gas flows into the inner cavity of the casing 10 through the casing end gas channel 13, that is, into the shell 101, usually the shell 101 is provided with an air outlet communicating with the outside to facilitate the discharge of the gas in the casing 10.

[0036] When the above structure is used, the first impeller 21 rotates rapidly to compress the gas in the first volute 20 into high-pressure gas under the action of the rapid rotation of the first impeller 21, the temperature of the gas after initial compression is relatively high, and after being cooled to a specified temperature by the inter-stage cooling system 4, the low-temperature and high-pressure gas flows into the second pull rod gas channel 34 through the second turbine air inlet, and flows into the inner cavity of the casing 10 along the thrust bearing cooling channel A, in this process, the low-temperature and high-pressure gas passes through the thrust bearing chamber, effectively cooling the thrust bearing. Therefore, the low-temperature gas introduced at the second turbine air inlet of the present application cools the thrust bearing, which enhances the cooling effect of the thrust bearing, thereby facilitating the normal operation of the dual-stage compressor, and without the need for additional water cooling channels, making the structure of the dual-stage compressor more compact, and without the need to consider the risk of water cooling leakage, making the dual-stage compressor safer and more reliable.

[0037] Optionally, the first-stage compressor 2 further comprises a first pull rod 22, the first pull rod 22 passes through the first impeller 21 to connect the first output end of the rotor 11, so as to better transmit the power of the rotor 11 to the first impeller 21 and make the first impeller 21 rotate stably.

[0038] It should be noted that the motor further comprises a stator 12 located in the casing 10, the stator 12 is arranged around the circumference of the rotor 11, the stator 12 is usually composed of a group of coils wound on an iron core, and the electromagnetic force is generated after being electrified, which drives the rotor 11 to rotate.

[0039] In order to improve the operation reliability of the stator 12, and further improve the operation reliability of the bipolar compressor, on the basis of the above embodiment, the primary compressor 2 further comprises a fan volute 23 and a fan 24, the fan volute 23 is arranged between the first end of the casing 10 and the primary volute 20, the fan 24 is located in the fan volute 23 and connected to the first output end of the rotor 11, and the circumferential wall of the fan volute 23 is provided with a fan volute gas outlet 25 for communicating the inner cavity and the outside thereof; the circumferential wall of the casing 10 is provided with a casing gas inlet 14 for communicating the outside and the inner cavity thereof, and the first end of the casing 10 is provided with a fan volute gas inlet 15 communicating with the inner cavity of the fan volute 23; wherein the casing gas inlet 14, the inner cavity of the casing 10, the fan volute gas inlet 15, the inner cavity of the fan volute 23 and the fan volute gas outlet 25 are sequentially communicated to form a stator cooling channel B.

[0040] It should be noted that during the operation of the motor 1, the stator 12 winding is subjected to electromagnetic force for a long time and generates a large amount of heat. If the stator 12 is not cooled, the high temperature of the stator 12 winding will cause the motor 1 to be damaged and affect the normal operation of the bipolar compressor. Therefore, the fan 24 is operated, and since the fan volute 23 is communicated with the inner cavity of the casing 10 through the fan volute gas inlet 15, the fan volute 23 and the inner cavity of the casing 10 both produce negative pressure, so that the normal temperature and pressure gas outside the casing 10 first flows into the inner cavity of the casing 10 through the casing gas inlet 14 to cool the stator 12, and after the stator 12 is cooled, the gas flows into the fan volute 23, and finally is discharged through the fan volute gas outlet 25. Therefore, the stator cooling channel B is arranged between the inner cavity of the casing 10 and the fan volute 23 to complete the cooling of the stator 12, thereby improving the service life and reliability of the stator 12, and further improving the operation reliability of the motor 1, that is, improving the operation reliability of the bipolar compressor. In addition, it should be noted that the gas for cooling the thrust bearing flows into the inner cavity of the casing 10 through the thrust bearing cooling channel A, and finally is discharged outside the casing 10 through the stator cooling channel B.

[0041] To enhance the cooling effect of the stator 12, on the basis of the above embodiment, a stator-rotor gap is left between one side of the stator 12 and the rotor 11, and the other side of the stator 12 is fixed to the inner circumferential wall of the casing 10 through the connecting plate 18, the connecting plate 18 divides the inner cavity of the casing 10 into a left inner cavity and a right inner cavity, and the connecting plate 18 is provided with an auxiliary air passage 19; the stator cooling channel B includes a first branch channel B1 and a second branch channel B2, the first branch channel B1 is sequentially communicated to form by the casing air inlet 14, the right inner cavity, the stator-rotor gap, the fan volute air inlet 15, the inner cavity of the fan volute 23, and the fan volute air outlet 25, and the second branch channel B2 is sequentially communicated to form by the casing air inlet 14, the auxiliary air passage 19, the left inner cavity, the fan volute air inlet 15, the inner cavity of the fan volute 23, and the fan volute air outlet 25.

[0042] It can be understood that the stator 12 is a stationary part of the motor 1, one side of the stator 12 is fixed to the inner circumferential wall of the casing 10 through the connecting plate 18, the rotor 11 is a rotating part of the motor 1, and a stator-rotor gap needs to be left between the stator 12 and the rotor 11, which should not be too large, and its size has an impact on the efficiency, power, noise, and manufacturing cost of the motor 1, that is, it needs to be set according to the required specifications. The connecting plate 18 divides the inner cavity of the casing 10 into a left inner cavity for accommodating the left part of the stator 12 and a right inner cavity for accommodating the right part of the stator 12, to ensure that the left part and the right part of the stator 12 are cooled, after the gas flows into the inner cavity of the casing 10 through the casing air inlet 14, part of the gas flows into the first branch channel B1 to take away the heat of the right part of the stator 12, and the other part of the gas flows into the second branch channel B2 to take away the heat of the left part of the stator 12, so that the gas fully contacts the stator 12 to cool it, thereby effectively improving the service life and reliability of the stator 12, and further effectively improving the operation reliability of the dual-pole compressor. It should be noted that the outer periphery of the rotor 11 is provided with a rotor 11 sheath, and the first branch channel B1 also cools the rotor 11 sheath, further improving the service life and reliability of the motor 1.

[0043] To improve the rotation performance of the rotor 11, a first radial bearing and a second radial bearing are respectively installed between the first output end of the rotor 11 and the first-stage end cover 102 and between the second output end of the rotor 11 and the second-stage end cover 103, the radial bearings are used to support the rotation of the rotor 11 and radially limit the rotor 11, so that the rotor 11 maintains a correct positional relationship with the casing 10.

[0044] However, under the condition of high-speed rotation of the rotor 11, the radial bearing is subjected to the action of the gas film shear force to generate a large amount of heat, causing damage to the radial bearing and affecting the rotation of the rotor 11. In order to improve the operation reliability of the rotor 11 and further improve the operation reliability of the double-pole compressor, on the basis of the above embodiment, a first bearing chamber 16 for accommodating the first radial bearing is arranged between the rotor 11 and the first end of the casing 10, and the inner cavity of the casing 10, the first bearing chamber 16, the inner cavity of the fan volute 23 and the fan volute gas outlet 25 are sequentially communicated to form a first radial bearing cooling channel C.

[0045] Specifically, a first radial bearing gap is left between the outer ring of the radial bearing and the first-stage end cover 102, and the first radial bearing gap is communicated with the inner cavity of the fan volute 23 and the inner cavity of the casing 10. Therefore, after the gas in the first branch channel B1 flows through the rotor-stator 11 gap, part of the gas flows into the first radial bearing gap, or after the gas in the second branch channel B2 flows through the left inner cavity, part of the gas flows into the first radial bearing gap. After the first radial bearing is cooled, the gas is discharged to the outside through the inner cavity of the fan volute 23, thereby completing the cooling of the first radial bearing and further improving the operation reliability of the rotor 11.

[0046] Further, a second bearing chamber 17 for accommodating the second radial bearing is arranged between the rotor 11 and the second end of the casing 10, and the thrust bearing chamber 37, the second bearing chamber 17 and the inner cavity of the casing 10 are sequentially communicated to form a second radial bearing cooling channel D.

[0047] Specifically, a second radial bearing gap is left between the outer ring of the second radial bearing and the second-stage end cover 103, and the second radial bearing gap is communicated with the inner cavity of the casing 10 and the thrust bearing chamber 37. Therefore, part of the gas flowing out of the thrust bearing chamber 37 flows into the second radial bearing gap, and after the second radial bearing is cooled, the gas is merged into the first branch channel B1, thereby completing the cooling of the second radial bearing and further improving the operation reliability of the rotor 11.

[0048] In order to prevent leakage of the thrust bearing cooling channel A, on the basis of the above embodiment, a sealing disc groove is arranged in the inner ring of the thrust bearing seat 33 and communicated with the thrust bearing chamber 37, a sealing disc 38 is arranged in the sealing disc groove and sealingly connected with the outer ring thereof, and the inner ring of the sealing disc 38 is sealingly connected with the outer periphery of the second-stage impeller 31.

[0049] It can be understood that part of the low-temperature high-pressure gas is located in the secondary volute 30 and is compressed into high-temperature high-pressure gas under the action of high-speed rotation of the secondary impeller 31, and another part of the low-temperature high-pressure gas flows into the thrust bearing cooling channel A through the secondary pull rod 32, that is, the gas pressure in the secondary volute 30 is higher than that in the thrust bearing chamber 37. The secondary volute 30 and the thrust bearing chamber 37 are isolated by the sealing disc 38. The pressure on the side of the sealing disc 38 close to the thrust bearing chamber 37 is lower than the pressure on the side of the sealing disc 38 close to the inner cavity of the secondary volute 30, so that the gas in the thrust bearing chamber 37 is not easy to flow into the inner cavity of the secondary volute 30, thereby enhancing the sealing effect of the thrust bearing cooling channel A, thereby facilitating the enhancement of the thrust bearing cooling effect.

[0050] Optionally, the inner ring of the sealing disc 38 is provided with a plurality of annular sealing teeth in sealing connection with the outer periphery of the secondary impeller 31, so as to further enhance the sealing effect between the thrust bearing chamber 37 and the secondary volute 30, that is, to further enhance the sealing effect of the thrust bearing cooling channel A.

[0051] In addition, on the basis of the above embodiment, please refer to Figure 2 , the thrust bearing seat 33 and the opposite end surface of the second end of the casing 10 are provided with a bearing groove 173 matched with the shape of the thrust bearing, the thrust bearing seat 33 is provided with a plurality of shell end grooves 171 from near to far away from the bearing groove 173, the thrust bearing seat 33 is provided with a plurality of bearing seat grooves 172 from near to far away from the bearing groove 173, and the plurality of bearing seat grooves 172, the bearing groove 173 and the plurality of shell end grooves 171 are sequentially communicated to form the thrust bearing chamber 37. The thrust bearing chamber 37 provided with the above structure has a large volume, so as to reduce the gas flow resistance, so that the thrust bearing is fully contacted with the gas, thereby effectively enhancing the thrust bearing cooling effect.

[0052] Optionally, the bearing groove 173 is provided with a thrust disc 39 sleeved on the rotor 11, and the outer ring of the thrust disc 39 is sleeved with the thrust bearing, so as to help the thrust bearing resist the axial thrust and impact of the rotor 11.

[0053] In order to adjust the gas flow in the thrust bearing cooling channel A, on the basis of the above embodiment, part of the secondary pull rod 32 passes through the secondary impeller 31 to connect the second end of the rotor 11, and another part of the secondary pull rod 32 is located outside the secondary impeller 31 and is provided with a gas flow adjusting member. The gas flow adjusting member is used to adjust the gas flow in the secondary pull rod gas channel 34, so as to facilitate the control of the thrust bearing cooling effect.

[0054] Further, the airflow adjusting member comprises an adjusting rod and an adjusting block, the adjusting rod is movably inserted into the sidewall of the secondary pull rod 32, and the insertion part of the adjusting rod is connected with the adjusting block located in the secondary pull rod air channel 34, so that the operator can directly control the size of the cross section of the secondary pull rod air channel 34 blocked by the adjusting block by moving the adjusting rod, that is, control the size of the opening of the secondary pull rod air channel 34, so as to quickly adjust the gas flow in the thrust bearing cooling channel A to the required gas flow value, and accurately control the thrust bearing cooling effect.

[0055] It should be noted that the required gas flow values of the thrust bearing cooling channel A, the stator cooling channel B, the first radial bearing cooling channel C and the second radial bearing cooling channel D in the bipolar compressor can be obtained by simulation calculation, and the number and size of the secondary pull rod air channel 34, the rotor air channel 35, the secondary impeller air channel 36, the casing end air channel 13 and the auxiliary air channel 19 are controlled according to the calculated gas flow values. Therefore, during the debugging of the bipolar compressor prototype, the size of the secondary pull rod 32 aperture can be controlled by blocking the secondary pull rod air channel 34 with the airflow adjusting member, and the debugging is ended only when the aperture of the secondary pull rod 32 meets the required gas flow value, so as to shorten the prototype debugging time. Alternatively, during the debugging of the bipolar compressor prototype, the size of the secondary pull rod 32 aperture can also be quickly determined by directly blocking the port of the secondary pull rod 32 with a wooden plug, so as to shorten the prototype debugging time.

[0056] It should be noted that in the present specification, the relationship terms such as first and second are only used to distinguish one entity from another entity, and do not necessarily require or imply any such actual relationship or order between the entities.

[0057] The various embodiments in the present specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between various embodiments can be referred to each other.

[0058] The above has introduced the bipolar compressor provided by the present application in detail. The principles and implementation manners of the present application are described by applying specific examples in this paper, and the above embodiment description is only used to help understand the method of the present application and its core idea. It should be noted that for ordinary skilled persons in the technical field, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A two-stage compressor, characterized in that: The invention comprises a first-stage volute (20) and a first-stage impeller (21) located therein, a second-stage volute (30) and a second-stage impeller (31) located therein, and a casing (10) and a rotor (11) located therein, wherein the first-stage impeller (21) is connected to a first output end of the rotor (11), and the second-stage impeller (31) is connected to a second output end of the rotor (11) via a second-stage pull rod (32), a thrust bearing seat (33) is sealed between the second-stage volute (30) and the second-stage impeller (31), and a thrust bearing chamber (37) for accommodating a thrust bearing is provided between the thrust bearing seat (33) and the casing (10); wherein a secondary tie rod air duct (34) is provided in the secondary tie rod (32), an air outlet of the first-stage volute (20) is communicated with the secondary tie rod air duct (34) through an interstage cooling system (4), the rotor (11) is provided with a rotor air duct (35), the second-stage impeller (31) is provided with a second-stage impeller air duct (36), an end of the casing close to the thrust bearing seat (33) is provided with a casing end air duct (13) communicated with the inner cavity of the casing (10), the second-stage tie rod air duct (34), the rotor air duct (35), the second-stage impeller air duct (36), the thrust bearing chamber (37) and the casing end air duct (13) are sequentially communicated to form a thrust bearing cooling channel (A); A fan volute (23) is provided between the first-stage volute (20) and the casing, a fan (24) sleeved on the rotor (11) is provided in the fan volute (23), a fan volute air outlet (25) for communicating the inner cavity and the outside of the fan volute (23) is provided on the peripheral wall, a casing air inlet (14) for communicating the outside and the inner cavity of the casing (10) is provided on the peripheral wall, and a fan volute air inlet (15) communicating with the inner cavity of the fan volute (23) is provided at one end of the casing (10) close to the fan volute (23); The housing air inlet (14), the inner cavity of the housing (10), the fan volute air inlet (15), the inner cavity of the fan volute (23), and the fan volute air outlet (25) are sequentially connected to form a stator cooling channel (B); A stator (12) is provided in the housing (10) and is arranged circumferentially around the rotor (11), and a stator-rotor gap is left between one side of the stator (12) and the rotor (11). The other side of the stator (12) is connected to the inner wall of the housing (10) via a connecting plate (18). The connecting plate (18) divides the inner cavity of the housing (10) into a left inner cavity and a right inner cavity, and an auxiliary airway (19) is provided on the connecting plate (18); The stator cooling channel (B) includes a first branch channel (B1) and a second branch channel (B2), wherein the first branch channel (B1) is formed by the casing air inlet (14), the right inner cavity, the stator-rotor gap, the fan volute air inlet (15), the inner cavity of the fan volute (23) and the fan volute air outlet (25) being connected in sequence, and the second branch channel (B2) is formed by the casing air inlet (14), the auxiliary air duct (19), the left inner cavity, the fan volute air inlet (15), the inner cavity of the fan volute (23) and the fan volute air outlet (25) being connected in sequence.

2. The two-stage compressor according to claim 1, characterized in that A first bearing chamber (16) for accommodating a first radial bearing is provided between one end of the casing (10) close to the fan volute (23) and the rotor (11), and the inner cavity of the casing (10), the first bearing chamber (16), the inner cavity of the fan volute (23) and the fan volute air outlet (25) are sequentially connected to form a first radial bearing cooling channel (C).

3. The two-stage compressor according to claim 1, characterized in that A second bearing chamber (17) for accommodating a second radial bearing is provided between one end of the housing (10) close to the thrust bearing seat (33) and the rotor (11), and the thrust bearing chamber (37), the second bearing chamber (17) and the inner cavity of the housing (10) are connected in sequence to form a second radial bearing cooling channel (D).

4. The two-stage compressor according to claim 1, characterized in that The thrust bearing seat (33) is provided with a sealing disc groove that is in communication with the thrust bearing chamber (37), and a sealing disc (38) is provided in the sealing disc groove and is sealed to its outer ring, and the inner ring of the sealing disc (38) is sealed to the outer periphery of the secondary impeller (31).

5. The two-stage compressor according to claim 1, characterized in that A bearing groove (173) adapted to the shape of the thrust bearing is provided between the opposite end faces of the housing (10) and the thrust bearing seat (33); the thrust bearing seat (33) is provided with a plurality of housing end grooves (171) from near to far away from the bearing groove (173); the thrust bearing seat (33) is provided with a plurality of bearing seat grooves (172) from near to far away from the bearing groove (173); the plurality of bearing seat grooves (172), the bearing grooves (173) and the plurality of housing end grooves (171) are connected in sequence to form the thrust bearing chamber (37).

6. The two-stage compressor according to any one of claims 1 to 5, characterized in that: A portion of the secondary tie rod (32) passes through the secondary impeller (31) and is connected to the second end of the rotor (11); another portion of the secondary tie rod (32) is placed outside the secondary impeller (31) and is provided with an airflow regulating member, which is used to regulate the gas flow in the secondary tie rod airway (34).

7. The two-stage compressor according to claim 6, characterized in that The airflow regulating member comprises an regulating rod and a regulating block. The regulating rod is movably inserted on the side wall of the secondary tie rod (32), and its insertion portion is connected to the regulating block located in the secondary tie rod air passage (34) to drive the regulating block to move and adjust the cross-sectional size of the secondary tie rod air passage (34) blocked by the regulating block.

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