Two-shaft hybrid pump

Abstract

Disclosed in the present invention is a two-shaft hybrid pump, which is characterized by comprising a pump body and two connection shafts; the pump body is internally provided with a Roots pump body chamber and a screw pump body chamber which are independent of each other; the pump body is provided with an air inlet, an air outlet and a connection channel, the air inlet connecting the Roots pump body chamber to the ambient atmosphere, the air outlet connecting the screw pump body chamber to the ambient atmosphere, and the connection channel communicating the Roots pump body chamber with the screw pump body chamber; two Roots rotor components meshed with each other are provided in the Roots pump body chamber, and the two Roots rotor components are respectively mounted on the two connection shafts; two screw rotor components meshed with each other are provided in the screw pump body chamber, and the two screw rotor components are respectively mounted on the two connection shafts. The present invention reduces space occupation, improves the vacuum level, and reduces costs.

Description

A two-shaft hybrid pump TECHNICAL FIELD

[0001] The present application relates to a vacuum pump, in particular to a two-shaft hybrid pump. BACKGROUND

[0002] There are many kinds of vacuum pumps, different vacuum pumps are used in different industries, for example, Roots vacuum pump and screw vacuum pump, two separate use, can also be used in combination. In the conventional way, such as patent number: CN202121962223.8, patent name: based on industrial high efficiency energy saving Roots screw vacuum pump group, this structure, there are the following shortcomings:

[0003] 1. The screw pump is arranged below the Roots pump, and the space is large;

[0004] 2. The Roots pump and the screw pump need to be driven by a separate motor, which not only has higher cost, but also has higher energy consumption;

[0005] 3. The outlet temperature of the screw pump is high, which is easy to damage, and in the environment with dust, dust blocking phenomenon is easy to appear, and the maintenance rate is high. SUMMARY

[0006] The purpose of the present application is to provide a two-shaft hybrid pump, which reduces the space occupation, ensures the vacuum effect, reduces the maintenance rate and prolongs the service life.

[0007] To achieve the above purpose, the technical scheme adopted by the present application is: a two-shaft hybrid pump, comprising a pump body and two parallel connecting shafts rotatably installed in the pump body;

[0008] The pump body is provided with a Roots pump cavity and a screw pump cavity which are independent of each other along the axis direction of the connecting shaft, the connecting shaft is rotatably connected with the two ends of the Roots pump cavity, and the other end of the connecting shaft is inserted into the screw pump cavity;

[0009] The pump body is provided with an air inlet, an air outlet and a connecting channel, the air inlet connects the Roots pump cavity with the outside atmosphere, the air outlet connects the screw pump cavity with the outside atmosphere, and the connecting channel connects the Roots pump cavity with the screw pump cavity;

[0010] The Roots pump cavity is provided with two Roots rotor components which are meshed with each other, the two Roots rotor components are respectively installed on the two connecting shafts, and the two Roots rotor components rotate to send the fluid entering the air inlet into the screw pump cavity through the connecting channel;

[0011] The screw pump body cavity is provided with two screw rotor components which are mutually engaged, the two screw rotor components are respectively installed on the two connecting shafts, and fluid sent into the screw pump body cavity by the connecting channel is discharged from the exhaust port when the two screw rotor components rotate.

[0012] In the technical scheme, the Roots rotor component and the connecting shaft are in an integrated structure.

[0013] In the technical scheme, the pump body is further provided with a first bearing cavity and a second bearing cavity, the first bearing cavity is located on the side of the Roots pump body cavity which is away from the screw pump body cavity, and the second bearing cavity is arranged on the opposite side of the first bearing cavity.

[0014] Two bearings are respectively installed in the first bearing cavity and the second bearing cavity, one end of the connecting shaft extends into the first bearing cavity, and the connecting shaft is rotatably connected with the pump body through the bearing in the first bearing cavity.

[0015] The other end of the connecting shaft extends into the second bearing cavity and is inserted into the screw pump body cavity, and the connecting shaft arranged in the second bearing cavity is rotatably connected with the pump body through the bearing.

[0016] In the technical scheme, one end of the connecting shaft is connected with the bearing in the first bearing cavity, and the other end of the connecting shaft has a spacing with the end face of the screw pump body cavity which is away from the Roots pump body cavity.

[0017] The screw rotor component close to the side of the Roots pump body cavity is installed on the connecting shaft, and the other end has a micro gap with the end face of the screw pump body cavity which is away from the Roots pump body cavity.

[0018] In the technical scheme, a partition plate is arranged in the Roots pump body cavity, the partition plate divides the Roots pump body cavity into a first-level Roots pump body cavity and a second-level Roots pump body cavity which are arranged in an axial direction, and the second-level Roots pump body cavity is arranged between the first-level Roots pump body cavity and the screw pump body cavity.

[0019] The Roots rotor component comprises a first-level Roots rotor body and a second-level Roots rotor body which are arranged in a spaced manner, the first-level Roots rotor body is arranged in the first-level Roots pump body cavity, and the second-level Roots rotor body is arranged in the second-level Roots pump body cavity.

[0020] The partition plate is provided with two connecting shaft through holes, and the middle part of each connecting shaft is located in one connecting shaft through hole.

[0021] In the technical scheme, the pump body is provided with an intermediate connecting channel which connects the first-level Roots pump body cavity and the second-level Roots pump body cavity, and the connecting channel connects the second-level Roots pump body cavity and the screw pump body cavity.

[0022] and / or, two said primary Roots rotor bodies rotate to send the fluid entering through said intermediate connecting channel into said secondary Roots pump body cavity;

[0023] two said secondary Roots rotor bodies rotate to send the fluid entering through said intermediate connecting channel into said secondary Roots pump body cavity, and the fluid is sent through said connecting channel into said screw pump body cavity.

[0024] In the above technical solution, the pump body comprises a primary pump body, a secondary pump body and a screw pump body, the primary pump body is sealingly connected with the secondary pump body, and the secondary pump body is sealingly connected with the screw pump body;

[0025] The primary Roots pump body cavity is arranged in the primary pump body, the secondary Roots pump body cavity is arranged in the secondary pump body, and the screw pump body cavity is arranged in the screw pump body;

[0026] and / or, the partition plate is arranged at the connection between the primary pump body and the secondary pump body.

[0027] In the above technical solution, the partition plate comprises a first plate body and a second plate body, the outer edges of the first plate body and the second plate body are clamped at the connection between the primary pump body and the secondary pump body, the opposite ends of the first plate body and the second plate body are in contact, and the opposite ends of the first plate body and the second plate body are respectively provided with grooves to form the shaft hole.

[0028] In the above technical solution, the outer wall of the pump body is further provided with a notch in communication with the connecting channel, and a sealing cover is mounted on the pump body to seal the notch.

[0029] and / or, a fluid treatment component can be detachably mounted in the connecting channel at the notch.

[0030] In the above technical solution, a driving device is further included, which is mounted on the pump body away from the screw pump body cavity, and can drive one of the shafts to rotate.

[0031] and / or, the end of the shaft away from the screw pump body cavity is provided with a gear, the gears at the ends of the two shafts are engaged, the driving device drives one of the gears and the shaft to rotate, and drives the other shaft to rotate through the other gear.

[0032] Due to the use of the above technical solution, the present application has the following advantages compared with the prior art:

[0033] 1. The Roots pump and screw pump in the application are arranged on the same axis, and the same driving device can drive the Roots pump and screw pump to rotate to perform vacuum pumping action, compared with the structure of being arranged up and down and two motors being distinguished respectively in the prior art, the cost is more low, the space occupation is smaller, and the transportation cost can be reduced;

[0034] 2. The two-stage Roots pump and screw pump are adopted in the application, the Roots pump constitutes a booster pump, and the screw pump constitutes a vacuum pump, so that the vacuum pumping efficiency and vacuum effect can be effectively improved;

[0035] 3. The two-stage Roots pump is arranged in front of the screw pump in the application, so that compression is generated by each stage of the Roots pump, heat is not excessively concentrated at the exhaust port of the screw pump, coking of carbon hydrogen mixture due to excessively high temperature of the exhaust port is prevented, the smoothness of vacuum pumping is ensured, the screw pump can be prevented from being damaged, the maintenance rate is reduced, and the service life is prolonged;

[0036] 4. The two-stage Roots pump is used to pump air in the application, dust and the like can be effectively prevented from entering the screw pump, the phenomenon of powder sticking and blocking is prevented, the maintenance rate is reduced, and the service life is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0037] Fig. 1 is a structure schematic view in an embodiment of the application;

[0038] Fig. 2 is a sectional structure schematic view in an embodiment of the application (the Roots pump is a two-stage Roots pump structure);

[0039] Fig. 3 is a local enlarged view of the connecting part of the screw rotor component and the shaft;

[0040] Fig. 4 is a gas flow path view in an embodiment of the application (the Roots pump is a two-stage Roots pump structure, the connecting channel is arranged above the pump body, and the structure in which the notch is not arranged to communicate with the connecting channel);

[0041] Fig. 5 is a structure schematic view of the Roots rotor component and the shaft in the connected state in an embodiment of the application (the Roots rotor component includes a first-stage Roots rotor body and a second-stage Roots rotor body);

[0042] Fig. 6 is an end surface structure schematic view of the connecting part of the middle partition plate and the shaft in Fig. 2;

[0043] Fig. 7 is a gas flow path view in another embodiment of the application (the Roots pump body cavity is a single cavity structure, and the connecting channel is arranged at the bottom of the pump body);

[0044] Fig. 8 is a structure schematic view of the Roots rotor component in a working state in an embodiment of the application;

[0045] Fig. 9 is a structure schematic view of the connecting channel in another embodiment of the application (the structure in which the notch is arranged on the upper surface of the pump body).

[0046] Wherein: 1, pump body; 2, connecting shaft; 3, Roots pump body cavity; 4, screw pump body cavity; 5, air inlet; 6, exhaust port; 7, connecting channel; 8, Roots rotor component; 9, screw rotor component; 10, stepped hole; 11, spline; 12, stepped limiting piece; 13, sealing cover; 14, first bearing cavity; 15, second bearing cavity; 16, bearing; 17, middle partition plate; 18, first stage Roots pump body cavity; 19, second stage Roots pump body cavity; 20, first stage Roots rotor body; 21, second stage Roots rotor body; 22, middle connecting channel; 23, first stage pump body; 24, second stage pump body; 25, screw pump body; 26, left connecting channel; 27, right connecting channel; 28, left middle connecting channel; 29, right middle connecting channel; 30, first plate body; 31, second plate body; 32, groove; 33, connecting shaft through hole; 34, driving device; 35, gear; 36, gear housing; 37, sealing plate; 38, left connecting channel; 39, right connecting channel; 40, connecting cavity. DETAILED DESCRIPTION

[0047] The application will be further described below in conjunction with the drawings and embodiments:

[0048] Embodiment one: referring to Figs. 1-9, a two-shaft hybrid pump includes a pump body 1 and two connecting shafts 2 parallel to each other and rotatably installed in the pump body 1; the two connecting shafts 2 are arranged at intervals in front and back (the position direction in the drawing, such as the direction of up, down, left and right, which are all taken as examples in the drawing).

[0049] The pump body 1 is arranged with a Roots pump body cavity 3 and a screw pump body cavity 4 independent of each other along the axis direction of the connecting shaft 2, the connecting shaft 2 is rotatably connected with both ends of the Roots pump body cavity 3, and the other end of the connecting shaft 2 is inserted into the screw pump body cavity 4; in this embodiment, the Roots pump body cavity 3 is arranged on the left side of the screw pump body cavity 4, and the two are arranged independently of each other. The middle part and the left end of the connecting shaft 2 are rotatably connected with the right side and the left side of the Roots pump body cavity 3 respectively, and the connection places are rotatably connected with sealing (such as oil seal), so as to ensure that the Roots pump body cavity 3 and the screw pump body cavity 4 are independent of each other, and the two are not communicated with each other from the connection place of the connecting shaft 2 and the pump body 1.

[0050] Referring to Figs. 2 and 4, the pump body 1 is provided with an air inlet 5, an exhaust port 6 and a connecting channel 7, the air inlet 5 connects the Roots pump body cavity 3 with the outside atmosphere, the exhaust port 6 connects the screw pump body cavity 4 with the outside atmosphere, and the connecting channel 7 connects the Roots pump body cavity 3 with the screw pump body cavity 4.

[0051] In the embodiment, the bottom of the pump body 1 is used for installation and fixation, the air inlet 5 is arranged at the top of the pump body 1 and communicates with the top of the Roots pump cavity 3, the air outlet 6 is arranged at the right end of the pump body 1 and communicates with the right end of the screw pump cavity 4, and the connecting channel 7 is arranged at the bottom of the pump body 1 (in the case of a single cavity of the Roots pump cavity, see FIGS. 7 and 8) and is used for connecting the Roots pump cavity 3 and the screw pump cavity 4.

[0052] Referring to FIGS. 2, 3 and 5, the Roots pump cavity 3 is provided with two Roots rotor components 8 which are meshed with each other, the two Roots rotor components 8 are respectively installed on the two connecting shafts 2, and when the two Roots rotor components 8 rotate, the fluid entering from the air inlet 5 is sent into the screw pump cavity 4 through the connecting channel 7.

[0053] The screw pump cavity 4 is provided with two screw rotor components 9 which are meshed with each other, the two screw rotor components 9 are respectively installed on the two connecting shafts 2, and when the two screw rotor components 9 rotate, the fluid sent into the screw pump cavity 4 through the connecting channel 7 is discharged from the air outlet 6.

[0054] In the embodiment, the Roots pump cavity is an “∞”-shaped cavity (8-shaped structure arranged horizontally), which is composed of two cylindrical cavities which are connected to each other at inner ends, and the two connecting shafts are coaxially arranged in the two cylindrical cavities, respectively. The Roots rotor component is also an “∞”-shaped structure (8-shaped structure arranged horizontally), the outer surfaces of the opposite two ends of the Roots rotor component are attached to the inner walls of the Roots pump cavity or have a micro gap therebetween (preferably, the micro gap is provided to ensure that the Roots rotor component does not contact the inner wall of the Roots pump cavity and is scratched when the Roots rotor component rotates), and the rotating directions of the two connecting shafts are opposite, and the top of each connecting shaft rotates towards the inner end. Since the two Roots rotor components are meshed with each other, the Roots pump cavity above the two Roots rotor components is an independent space, and the Roots pump cavity below the two Roots rotor components is another independent space. When the two connecting shafts rotate, the external fluid (gas) is pressed into the space below the two Roots rotor components from the air inlet, and then is sent into the left end of the screw pump cavity through the connecting channel. The outer surfaces of the two screw rotor components have a micro gap with the inner surfaces of the screw pump cavities on the corresponding sides, the outer surface of the screw rotor component has a spiral groove (spiral exhaust groove), the width of the spiral groove gradually decreases from left to right, and the screw rotor component on the side of the spiral groove is meshed with the spiral groove of the adjacent screw rotor component (and has a gap therebetween, and does not contact each other). Thus, the fluid sent into the screw pump cavity through the connecting channel is discharged to the right through the gap of the spiral groove and is discharged through the air outlet, thereby realizing the action of vacuumizing.

[0055] In the embodiment, the Roots pump cavity and the Roots rotor component constitute a Roots pump, the screw pump cavity and the screw rotor component constitute a screw pump, and the Roots rotor component and the screw rotor component are installed on the same shaft, that is, the screw pump and the Roots pump are arranged on the same axis, so that the same driving device can drive the Roots pump and the screw pump to work at the same time, thereby reducing the space occupation, reducing the transportation and installation costs, and the cost is also lower.

[0056] Referring to FIGS. 2 and 3, in the embodiment, the middle part of the screw rotor component 9 has a coaxially arranged stepped hole 10, which includes a left hole and a right hole. The diameter of the left hole is smaller than that of the right hole, and the diameter of the left hole matches the outer diameter of the shaft. The right end of the shaft has a threaded hole, and the outer surface of the shaft in the screw pump cavity has a key groove. The left hole also has a key groove. The shaft 2 and the screw rotor component 9 are connected through a spline 11. The inner end of the spline 11 is clamped in the key groove of the shaft 2, and the outer end of the spline is clamped in the key groove of the left hole, thereby achieving the circumferential limiting between the screw rotor component and the shaft, preventing relative rotation therebetween. A stepped limiting piece 12 is installed in the right hole. The left side surface of the middle part of the stepped limiting piece abuts against the left end surface of the right hole, and the left end of the stepped limiting piece abuts against the right side surface of the shaft. Then, the stepped limiting piece and the right end of the shaft are connected through a bolt passing through the threaded hole, thereby axially fixing the screw rotor component and the shaft, preventing them from moving away from each other in the axial direction. Further, a sealing cover 13 is installed at the right end of the screw rotor component 9. The sealing cover 13 seals the right end of the right hole, thereby preventing gas from entering the right hole and ensuring the vacuum effect.

[0057] Meanwhile, in the present application, the right end of the shaft and the right end of the screw pump cavity are not connected, and have an axial spacing, that is, the right end of the shaft and the screw rotor component are a cantilever screw structure (the left end of the screw rotor component is supported by the rotating connection between the shaft and the pump body, and the right end is not limited, that is, a cantilever structure). In this structure, it is convenient to debug and adjust the spacing between the two screw rotor components during assembly, thereby ensuring the engagement between the two screw rotor components. The two screw rotor components do not contact each other, but only have a small gap therebetween, and do not rub against each other, thereby ensuring the vacuum quality.

[0058] The Roots rotor component and the shaft are in an integrated structure. In this way, the coaxiality can be effectively ensured.

[0059] Referring to Fig. 2, the pump body 1 is further provided with a first bearing cavity 14 and a second bearing cavity 15, the first bearing cavity 14 is located on the side of the Roots pump body cavity 3 away from the screw pump body cavity 4, and the second bearing cavity 15 is arranged on the opposite side of the first bearing cavity 14; wherein the first bearing cavity 14 is located on the left side of the Roots pump body cavity 3, and the second bearing cavity 15 is located on the right side of the Roots pump body cavity 3, i.e. the second bearing cavity 15 is located in the screw pump body cavity 4.

[0060] Referring to Fig. 2, two bearings 16 are respectively arranged in the first bearing cavity 14 and the second bearing cavity 15, the left end of the connecting shaft 2 extends into the first bearing cavity 14 and is rotatably connected with the pump body 1 through the bearings 16 in the first bearing cavity 14;

[0061] The right end of the connecting shaft 2 extends into the second bearing cavity 15 and is inserted into the screw pump body cavity 4, and the connecting shaft 2 arranged in the second bearing cavity 15 is rotatably connected with the pump body 1 through the bearings 16. The connecting shaft is rotatably connected with the body through bearings and oil seals, which ensures the smoothness and stability of rotation. The oil seal (or other sealing member) is arranged at the connection between the connecting shaft and the body, which can seal and prevent air leakage. Meanwhile, the left end of the screw rotor component abuts against the outer ring of the bearing in the second bearing cavity, which limits the axial movement of the screw rotor component towards the Roots rotor component, and the stepped limiting member limits the axial movement of the screw rotor component away from the Roots rotor component.

[0062] Referring to Fig. 2, the left end of the connecting shaft 2 is connected with the bearings 16 in the first bearing cavity 15, and there is a gap between the right end of the connecting shaft 2 and the right end face of the screw pump body cavity 4, and there is also a gap between the right end of the connecting shaft 2 and the right end of the screw rotor component 9.

[0063] The left end of the screw rotor component is mounted on the connecting shaft, and there is a micro gap between the right end of the screw rotor component and the right end face of the screw pump body cavity, so that when the connecting shaft drives the screw rotor component to rotate, the screw rotor component will not come into contact with the inner wall of the screw pump body cavity to generate friction and prevent damage.

[0064] Referring to Figs. 2, 4 and 6, a partition plate 17 is arranged in the Roots pump body cavity 3, the partition plate 17 divides the Roots pump body cavity 3 into a first-stage Roots pump body cavity 18 and a second-stage Roots pump body cavity 19 arranged in the axial direction, and the second-stage Roots pump body cavity 19 is arranged between the first-stage Roots pump body cavity 18 and the screw pump body cavity 4;

[0065] The Roots rotor part 8 comprises a first-stage Roots rotor body 20 and a second-stage Roots rotor body 21, the first-stage Roots rotor body 20 is arranged in the first-stage Roots pump cavity 18, and the second-stage Roots rotor body 21 is arranged in the second-stage Roots pump cavity 19.

[0066] The middle plate 17 is provided with two shaft through holes 33, and the middle part of each shaft 2 is arranged in one shaft through hole 33.

[0067] The pump body 1 is provided with an intermediate connecting channel 22 connecting the first-stage Roots pump cavity 18 and the second-stage Roots pump cavity 19, and the connecting channel 7 connects the second-stage Roots pump cavity 19 and the screw pump cavity 4.

[0068] When the two first-stage Roots rotor bodies 20 rotate, the fluid entering the inlet 5 is sent into the second-stage Roots pump cavity 19 through the intermediate connecting channel 22;

[0069] When the two second-stage Roots rotor bodies 21 rotate, the fluid sent into the second-stage Roots pump cavity 19 through the intermediate connecting channel 22 is sent into the screw pump cavity 4 through the connecting channel 7.

[0070] In this embodiment, the Roots pump adopts a two-stage Roots pump. Since the rotating directions of the corresponding shafts in the first-stage Roots pump cavity and the second-stage Roots pump cavity are the same, the rotating directions of the first-stage Roots rotor body and the second-stage Roots rotor body are the same. The two first-stage Roots rotor bodies drive the gas to flow from top to bottom, and the second-stage Roots rotor bodies also drive the gas to flow from top to bottom. Therefore, the structure of the two-stage Roots pump is that the intermediate connecting channel is arranged around the second-stage Roots pump cavity, the bottom of the intermediate connecting channel is a fluid inlet, and the top of the intermediate connecting channel is a fluid outlet. The left end of the fluid inlet is connected with the bottom of the first-stage pump cavity, and the right end of the fluid inlet is connected with the top of the second-stage Roots pump cavity. The connecting channel is arranged at the bottom of the pump body, the left end of the connecting channel is connected with the bottom of the second-stage Roots pump cavity, and the right end of the connecting channel is connected with the left end of the screw pump cavity. In this way, during the operation, the shafts drive the two shafts to rotate at the same time, that is, the first-stage Roots rotor body and the second-stage Roots rotor body rotate at the same time. The two first-stage Roots rotor bodies suck the gas at the inlet into the first-stage Roots pump cavity below the first-stage Roots rotor body (primary compression), and send the gas into the second-stage Roots pump cavity above the second-stage Roots rotor body through the intermediate connecting channel. At the same time, the second-stage Roots rotor bodies suck the gas above the second-stage Roots rotor bodies into the second-stage Roots pump cavity below the second-stage Roots rotor bodies, and send the gas into the screw pump cavity through the connecting channel (secondary compression). The gas is discharged from the exhaust port through the screw rotor part, so as to realize the vacuum suction action.

[0071] In the embodiment, the Roots pump adopts a two-stage Roots pump, which can realize two-stage compression in limited space, improve vacuum degree and vacuum efficiency, reduce space occupation, reduce energy consumption, and save cost. At the same time, the heat generated during the vacuum compression process of the gas by the first-stage Roots rotor body can be dissipated in advance, which can effectively prevent the temperature of the screw rotor component at the rear end from being too high, effectively prevent damage to the screw rotor component caused by high temperature, and the temperature of the screw rotor component is lower, which is not easy to cause coking of the hydrocarbon mixture (high temperature is easy to cause coking of the hydrocarbon mixture and blockage problem), prevents blockage of the screw rotor component and affects the vacuum pumping problem, ensures the stability of the vacuum pumping, reduces the temperature of the exhaust port, reduces the maintenance rate, and prolongs the service life. When the two-stage Roots vacuum pump is used to process the process medium, because the performance of the two-stage pump can form different compression ratios for the first-stage pump, the temperature of the process medium discharged from the first-stage Roots pump body cavity can reach a higher and stable temperature after the calculation and design of a compression ratio range value, and the process medium enters the second-stage Roots pump body cavity. The process medium is further compressed in the second-stage Roots pump body cavity, which is convenient for the subsequent screw pump rotor component to pump, and further improves the vacuum degree. Because the intermediate connecting channel in the embodiment covers the outside of the entire second-stage Roots pump body cavity, that is, the intermediate connecting channel has a large coverage area, which is convenient for heat dissipation.

[0072] At the same time, the gas in the first-stage Roots pump body cavity can be directly sent to the second-stage Roots pump body cavity through the intermediate connecting channel, and the gas in the second-stage Roots pump body cavity is directly sent to the screw pump body cavity through the connecting channel, and the flow channel for vacuum pumping is relatively short. Moreover, the connecting channel and the intermediate connecting channel can be set wider, which is convenient for heat dissipation, and at the same time, when the air with dust is pumped, it is also not easy to cause the phenomenon of powder jamming. In the embodiment, the Roots rotor component is beside (left side) the screw rotor component, and the Roots rotor component also plays a role of a balance weight for the screw rotor component, which is used to balance the stress of the screw rotor component, so that the screw rotor component is a cantilever screw structure, which is convenient for assembly, debugging, and reduces the assembly difficulty. At the same time, the two-stage Roots pump is adopted, and the Roots pump not only plays a role of a vacuum pump, but also plays a role of a booster pump, which improves the vacuum pumping efficiency.

[0073] In the present application, the dry screw pump is formed by two screw rotor components and a screw pump body cavity, and is a non-wet structure, i.e. no lubricating liquid is added inside. In this way, the screw pump is suitable for working in a high dust environment and reduces the occurrence of blockage. In order to reduce the occurrence of blockage, a two-stage Roots pump structure is adopted, i.e. two-stage compression and pressure increase are performed by using a Roots pump. When the gas with dust enters the first adjacent screw rotor components in the screw pump body cavity, the dust is not easy to stick to the lubricating liquid to cause blockage due to the absence of lubricating liquid, and the pressure of the gas flow entering the screw pump body cavity is high, so the dust is discharged at a high speed. Even if blockage occurs, the normal use time can be prolonged and the frequency of cleaning and maintenance can be reduced.

[0074] In the present application, referring to FIGS. 2 and 4, the pump body 1 is a split structure, and includes a first pump body 23, a second pump body 24, and a screw pump body 25. The first pump body 23 is sealingly connected to the second pump body 24, and the second pump body 24 is sealingly connected to the screw pump body 25.

[0075] The first Roots pump cavity 18 is arranged in the first pump body 23 and communicates with the right end surface of the first pump body 23. The second Roots pump cavity 19 is arranged in the second pump body 24 and communicates with the left end surface of the second pump body 24. The screw pump cavity 4 is arranged in the screw pump body 25 and communicates with the left end surface of the screw pump body 25.

[0076] The partition plate 17 is arranged at the connection between the first pump body 23 and the second pump body 24.

[0077] A left concave cavity is arranged at the right end surface of the first pump body in a circumferential direction, and the inner end of the left concave cavity communicates with the first pump body cavity. A right concave cavity is arranged at the left end surface of the second pump body, and the inner end of the right concave cavity communicates with the second pump body cavity. When the pump body is assembled, the right end surface of the first pump body contacts the left end surface of the second pump body, and is locked by a bolt. The left concave cavity is arranged opposite to the right concave cavity, and the outer edge of the partition plate is clamped into the second concave cavity and the right concave groove to limit the partition plate. In order to ensure sealing, a sealing gasket is arranged at the connection between the first pump body and the second pump body to prevent air leakage. When the screw pump body is assembled, the left end surface of the screw pump body contacts the right end surface of the second pump body, and is locked by a bolt. A sealing gasket is arranged at the connection between the screw pump body and the second pump body to prevent air leakage and ensure sealing effect.

[0078] Part of the connecting channel is on the secondary pump body and the other part is on the screw pump body, and the two are oppositely arranged. After the secondary pump body and the screw pump body are sealingly connected, a complete connecting channel is formed. Preferably, the connecting channel 7 includes a left connecting channel 26 and a right connecting channel 27. The left end of the left connecting channel is in communication with the cavity of the secondary Roots pump body, and the right end is in communication with the bottom surface of the right end of the secondary pump body (in this embodiment, the right end surface of the secondary pump body, see Fig. 4). The right end of the right connecting channel is in communication with the cavity of the screw pump body, and the left end is in communication with the bottom surface of the left end of the screw pump body (in this embodiment, the left end surface of the screw pump body). After the secondary pump body and the screw pump body are connected, the right end of the left connecting channel is in communication with the left end of the right connecting channel, and the connection is sealingly connected, thereby forming a complete connecting channel and realizing the communication between the cavity of the secondary Roots pump body and the cavity of the screw pump body. Similarly, part of the intermediate connecting channel is on the primary pump body and the other part is on the secondary pump body. After the primary pump body and the secondary pump body are sealingly connected, a complete intermediate connecting channel is formed. Preferably, the intermediate connecting channel 22 includes a left intermediate connecting channel 28 and a right intermediate connecting channel 29. The left end of the left intermediate connecting channel is in communication with the bottom of the cavity of the primary Roots pump body, and the right end is in communication with the bottom surface of the right end of the primary pump body. The right intermediate connecting channel surrounds the outside of the cavity of the secondary Roots pump body. The right end of the right intermediate connecting channel is in communication with the top of the cavity of the secondary Roots pump body, and the left end is in communication with the bottom surface of the left end of the secondary pump body, see Fig. 4. After the secondary pump body and the primary pump body are connected, the right end of the left intermediate connecting channel is in communication with the left end of the right intermediate connecting channel, and the connection is sealingly connected, thereby forming a complete intermediate connecting channel and realizing the communication between the cavity of the primary Roots pump body and the cavity of the secondary Roots pump body.

[0079] As shown in Figs. 2 and 6, the partition plate 17 includes a first plate body 30 and a second plate body 31. The outer edges of the first plate body 30 and the second plate body 31 are clamped at the connection between the primary pump body 23 and the secondary pump body 24. The opposite ends of the first plate body 30 and the second plate body 31 are in contact, and the opposite ends of the first plate body 30 and the second plate body 31 are respectively provided with grooves 32, thereby forming the shaft through hole 33.

[0080] In this way, when the partition plate is assembled, the upper and lower clamping mode is directly used, the grooves of the first plate body and the second plate body are clamped into the top and bottom of the connecting shaft between the first rotor component and the second rotor component, so as to divide the Roots pump cavity into two independent first and second Roots pump cavities. Wherein, an oil seal or other sealing element is arranged at the connecting position of the connecting shaft through hole and the connecting shaft, so as to realize sealing, so that the first and second Roots pump cavities will not leak gas from the connecting shaft through hole. Of course, the sealing element can also not be arranged, so that the connecting shaft through hole and the connecting shaft have a micro gap, so that the micro gap connects the first and second Roots pump cavities, and the vacuum pumping effect will not be affected.

[0081] Referring to Figures 1 and 2, the drive device 34 is mounted on the pump body 1 away from the screw pump cavity 4, and the drive device 34 can drive one of the connecting shafts 2 to rotate;

[0082] The left end of the connecting shaft 2 is provided with a gear 35, and the gears 35 at the ends of the two connecting shafts 2 are engaged, the drive device 34 drives one of the gears 35 and the connecting shaft 2 to rotate, and drives the other connecting shaft 2 to rotate through the other gear 35. Wherein, the drive device adopts a motor, or a combination of a motor and a speed reducer, in this embodiment, the drive device adopts a motor as an example. The output shaft of the motor has a gear, which is engaged with a gear on one of the connecting shafts. When the motor is working, the two connecting shafts rotate in opposite directions, and the Roots rotor component and the screw rotor component are driven to rotate at the same time, so that the Roots rotor component and the screw rotor component are used for vacuum pumping. Or the output shaft of the motor is directly connected with the gear at the end of one of the connecting shafts, so as to drive the two connecting shafts to rotate at the same time, in this embodiment, referring to Figure 2, the motor is directly connected with the gear at the end of one of the connecting shafts, so as to reduce the space occupation. In this way, the same motor can be used for driving, the cost is lower, the energy consumption is lower, and the installation is simpler.

[0083] In the present application, the frame does not need to be arranged to support the pump body, the volume is small, the cost is low, the installation is simple, the transportation is convenient, and the running stability is good.

[0084] Further, in the present application, the first bearing cavity is arranged on the primary pump body on the opposite side away from the primary Roots pump body cavity, that is, the first bearing cavity is arranged on the primary pump body and communicates with the left end face of the primary pump body, and a hole position is provided between the first bearing cavity and the primary Roots pump body cavity for the shaft to pass into the first bearing cavity and the primary Roots pump body cavity, and an oil seal is arranged in the hole position to prevent air leakage, or other sealing members are arranged.

[0085] Further, since the bearing works for a long time and is prone to high temperature, a cooling cavity (not shown in the figure) is arranged in the primary pump body outside the first bearing cavity, and a cooling cavity is also arranged in the secondary pump body outside the second bearing cavity. The cooling cavities are wrapped outside the corresponding bearing cavities, and liquid inlet pipes and liquid outlet pipes are arranged on the two cooling cavities to communicate with the cooling cavities. The liquid inlet pipes are used for the inlet of cooling medium, and the liquid outlet pipes are used for the outlet of cooling medium. The cooling medium is introduced into the cooling cavities to cool the bearings, thereby preventing the bearings and the shaft from generating high temperature and preventing deformation of the shaft to ensure the coaxiality of the shaft, thereby ensuring the mutual cooperation relationship of the Roots rotor component and the screw rotor component during rotation and the cooperation relationship with the corresponding Roots pump body cavity and screw pump body cavity, preventing the phenomenon of jamming, and preventing scratches of the Roots pump body cavity, the screw pump body cavity, the Roots rotor component and the screw rotor component, ensuring the vacuum degree, reducing the maintenance rate and prolonging the service life.

[0086] Preferably, the bearing is a single-row angular contact bearing. When the bearing and the shaft are installed, bearing seats are arranged at the left and right ends of the bearing to clamp the outer ring of the bearing. At the same time, gaskets can be added during assembly to adjust the position of the bearing, thereby fine-tuning the shaft to adjust the gap between the Roots rotor component and the Roots pump body cavity to prevent the phenomenon of jamming.

[0087] In another embodiment, as shown in FIG. 9, the outer wall of the pump body 1 is further provided with a notch communicating with the connecting channel 7, and the pump body 1 is provided with a sealing cover 37 sealing the notch.

[0088] The connecting channel at the notch is further provided with a fluid treatment component which can be removed.

[0089] In the embodiment, the connecting channel 7 includes a left connecting channel 38 and a right connecting channel 39. The left end of the left connecting channel 38 is in communication with the two-stage Roots pump cavity 19, and the other end is in communication with the bottom of the right end face of the two-stage pump body 24. The right end of the right connecting channel 39 is in communication with the screw pump cavity 4, and the other end is in communication with the bottom of the left end face of the screw pump body 25. That is, the right end of the left connecting channel 38 constitutes an outlet, and the left end of the right connecting channel 39 constitutes an inlet. Then, the sealing plate or the fluid treatment component is installed above the outlet and the inlet, so that the outlet and the inlet are connected to form a complete connecting channel.

[0090] Preferably, the bottom of the sealing plate 37 or the fluid treatment component has a connecting cavity 40, which covers the outside of the outlet and the inlet. Then, the two ends of the sealing plate 37 are locked outside the two-stage pump body 24 and the screw pump body 25, respectively, so as to connect the inlet and the outlet. In this way, the connecting cavity, the left connecting channel and the right connecting channel constitute a complete connecting channel. Preferably, the notch is arranged on the side wall of the pump body, but not on the bottom, so as to facilitate the installation and disassembly of the sealing plate.

[0091] In this way, the side of the connecting channel can be directly communicated with the outer wall of the pump body, so that the operator can directly open the sealing cover plate or the fluid treatment component to expose the connecting channel. The operator can observe the internal conditions of the Roots pump cavity and the screw pump cavity through the connecting channel. In this way, the operator can make a simple inquiry without disassembling the pump, and can disassemble and repair the pump in a targeted manner. Meanwhile, the operator can also observe the internal conditions during assembly and debugging, so as to facilitate the debugging.

[0092] Further, the fluid treatment component, such as a filter, a caustic pack, a cooler or a heater, can also be installed in the connecting cavity. For example, the filter can be installed to filter the dust and other substances that need to enter the screw pump cavity, so as to prevent the dust and other substances from blocking the gap between the screw rotor components or the gap between the screw rotor components and the screw pump cavity. The caustic pack is used for water vapor adsorption, the cooler is used for air cooling, and the heater is used for air heating. Alternatively, other mechanisms can be added according to the actual required functions to solve the corresponding problems.

[0093] In the description of the present application, it should be understood that the terms “upper”, “lower”, “top”, “bottom”, “inner”, “outer” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify 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. In the description of the present application, the meaning of “a plurality of” is two or more, unless otherwise specifically limited.

[0094] In the present application, unless specifically defined and limited otherwise, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, such as, for example, two mechanical abutting or touching connection modes formed by abutting, touching and the like, two direct hanging or hanging connection through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

Claims

1. A two-shaft hybrid pump characterized by: The pump body and two parallel connecting shafts are rotatably installed in the pump body; The pump body is provided with a Roots pump cavity and a screw pump cavity which are arranged along the axis of the connecting shaft and are independent of each other, the connecting shaft is rotatably connected with the two ends of the Roots pump cavity, and the other end of the connecting shaft is inserted into the screw pump cavity; The pump body is provided with an air inlet, an air outlet and a connecting channel, the air inlet is connected with the Roots pump cavity and the atmosphere, the air outlet is connected with the screw pump cavity and the atmosphere, and the connecting channel is connected with the Roots pump cavity and the screw pump cavity; The Roots pump cavity is provided with two Roots rotor components which are meshed with each other, the two Roots rotor components are respectively installed on the two connecting shafts, and the two Roots rotor components rotate to send the fluid entering the air inlet into the screw pump cavity through the connecting channel; The screw pump cavity is provided with two screw rotor components which are meshed with each other, the two screw rotor components are respectively installed on the two connecting shafts, and the two screw rotor components rotate to discharge the fluid sent into the screw pump cavity through the connecting channel from the air outlet.

2. The two-shaft hybrid pump of claim 1, wherein: The Roots rotor component and the connecting shaft are in an integrated structure.

3. The two-shaft hybrid pump of claim 1, wherein: The pump body is further provided with a first bearing cavity and a second bearing cavity, the first bearing cavity is located on the side of the Roots pump cavity away from the screw pump cavity, and the second bearing cavity is arranged on the opposite side of the first bearing cavity; The first bearing cavity and the second bearing cavity are respectively provided with two bearings, one end of the connecting shaft extends into the first bearing cavity and is rotatably connected with the pump body through the bearings in the first bearing cavity; The other end of the connecting shaft extends into the second bearing cavity and is inserted into the screw pump cavity, and the connecting shaft arranged in the second bearing cavity is rotatably connected with the pump body through the bearings.

4. The two-shaft hybrid pump of claim 3, wherein: One end of the connecting shaft is connected with the bearings in the first bearing cavity, and the other end of the connecting shaft has a gap with the end face of the screw pump cavity away from the Roots pump cavity; The screw rotor component close to the side of the Roots pump cavity is installed on the connecting shaft, and the other end has a micro gap with the end face of the screw pump cavity away from the Roots pump cavity.

5. The two-shaft hybrid pump of claim 1, wherein: The Roots pump cavity is provided with a partition plate, the partition plate divides the Roots pump cavity into a first-stage Roots pump cavity and a second-stage Roots pump cavity which are arranged along the axial direction, and the second-stage Roots pump cavity is arranged between the first-stage Roots pump cavity and the screw pump cavity; The Roots rotor component comprises a first-stage Roots rotor body and a second-stage Roots rotor body which are arranged at intervals, the first-stage Roots rotor body is arranged in the first-stage Roots pump cavity, and the second-stage Roots rotor body is arranged in the second-stage Roots pump cavity; The partition plate is provided with two connecting shaft through holes, and the middle part of each connecting shaft is located in one connecting shaft through hole.

6. The two-shaft hybrid pump of claim 5, wherein: The pump body is provided with an intermediate connecting channel which connects the first-stage Roots pump cavity and the second-stage Roots pump cavity, and the connecting channel connects the second-stage Roots pump cavity and the screw pump cavity. And / or, the fluid entering the intake port is sent into the secondary Roots pump cavity through the intermediate connecting channel when the two primary Roots rotor bodies rotate; The fluid sent into the secondary Roots pump cavity through the intermediate connecting channel when the two secondary Roots rotor bodies rotate is sent into the screw pump cavity through the connecting channel.

7. The two-shaft hybrid pump of claim 5, wherein: The pump body comprises a primary pump body, a secondary pump body and a screw pump body, the primary pump body is sealingly connected with the secondary pump body, and the secondary pump body is sealingly connected with the screw pump body; The primary Roots pump cavity is arranged in the primary pump body, the secondary Roots pump cavity is arranged in the secondary pump body, and the screw pump cavity is arranged in the screw pump body; And / or, the partition plate is arranged at the connection between the primary pump body and the secondary pump body.

8. The two-shaft hybrid pump of claim 7, wherein: The partition plate comprises a first plate body and a second plate body, the outer edges of the first plate body and the second plate body are clamped at the connection between the primary pump body and the secondary pump body, the opposite ends of the first plate body and the second plate body are in contact, recesses are arranged at the opposite ends of the first plate body and the second plate body respectively, and the through hole of the connecting shaft is formed.

9. The two-shaft hybrid pump of claim 1, wherein: The outer wall of the pump body is further provided with a notch in communication with the connecting channel, and a sealing cover is mounted on the pump body to seal the notch; And / or, a fluid treatment component can be detachably mounted in the connecting channel at the notch.

10. The two-shaft hybrid pump of claim 1, wherein: The driving device is mounted on the pump body away from the screw pump cavity, and the driving device can drive one of the connecting shafts to rotate; And / or, the end of the connecting shaft away from the screw pump cavity is provided with a gear, the gears at the ends of the two connecting shafts are engaged, the driving device drives one of the gears and the connecting shaft to rotate, and drives the other connecting shaft to rotate through the other gear.

Images