Two-shaft mixing pump

Abstract

The utility model discloses a two-shaft mixing pump. The two-shaft mixing pump is characterized by comprising a pump body and two connecting shafts, a roots pump body cavity and a screw pump body cavity which are mutually independent are arranged in the pump body; the pump body is provided with an air inlet, an air outlet and a connecting channel, the roots pump body cavity is communicated with the outside atmosphere through the air inlet, the screw pump body cavity is communicated with the outside atmosphere through the air outlet, and the roots pump body cavity is communicated with the screw pump body cavity through the connecting channel. Two roots rotor parts which are meshed with each other are arranged in a cavity of the roots pump body, and the two roots rotor parts are respectively arranged on the two connecting shafts; and two screw rotor parts which are meshed with each other are arranged in a cavity of the screw pump body, and the two screw rotor parts are respectively mounted on the two connecting shafts. According to the utility model, the occupied space is reduced, the vacuum degree is improved, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to a vacuum pump, in particular to a two-shaft mixing pump. Background Art

[0002] There are many types of vacuum pumps, and different vacuum pumps are used in different industries. For example, Roots vacuum pumps and screw vacuum pumps can be used alone or in combination. When used in combination, in the conventional way, such as patent number: CN202121962223.8, patent name: Based on industrial high-efficiency and energy-saving Roots screw vacuum pump group, this structure has the following shortcomings:

[0003] 1. The screw pump is set below the Roots pump, which takes up a lot of space;

[0004] 2. Both Roots pumps and screw pumps require a separate motor to drive them, which is not only more expensive, but also consumes more energy;

[0005] 3. The air outlet temperature of the screw pump is high and it is easy to be damaged. At the same time, in a dusty environment, it is prone to dust clogging and the maintenance rate is relatively high. Summary of the invention

[0006] The utility model aims to provide a two-shaft mixing pump, which reduces space occupation, ensures vacuum effect, reduces maintenance rate and prolongs service life by using the structure.

[0007] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a two-shaft mixing pump, comprising a pump body and two connecting shafts which are parallel to each other and rotatably installed in the pump body;

[0008] The pump body is provided with mutually independent Roots pump body cavities and screw pump body cavities along the axial direction of the connecting shaft, the connecting shaft is rotatably connected with both ends of the Roots pump body cavity, and the other end of the connecting shaft is inserted into the screw pump body 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 body cavity with the outside atmosphere, the air outlet connects the screw pump body cavity with the outside atmosphere, and the connecting channel connects the Roots pump body cavity with the screw pump body cavity;

[0010] Two mutually meshing Roots rotor components are arranged in the Roots pump body cavity, and the two Roots rotor components are respectively mounted on the two connecting shafts. When the two Roots rotor components rotate, the fluid entering from the air inlet is sent into the screw pump body cavity through the connecting channel;

[0011] Two mutually meshing screw rotor components are arranged in the screw pump body cavity, and the two screw rotor components are respectively mounted on the two connecting shafts. When the two screw rotor components rotate, the fluid sent into the screw pump body cavity through the connecting channel is discharged from the exhaust port.

[0012] In the above technical solution, the Roots rotor component and the connecting shaft are an integral structure.

[0013] In the above technical solution, 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 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 installed in the first bearing cavity and the second bearing cavity respectively, one end of the connecting shaft extends into the first bearing cavity and is rotatably connected to the pump body via the bearing in the first bearing cavity;

[0015] The other end of the coupling shaft extends to the second bearing cavity and is inserted into the screw pump body cavity, and the coupling shaft arranged in the second bearing cavity is rotatably connected to the pump body via a bearing.

[0016] In the above technical solution, one end of the connecting shaft is connected to the bearing in the first bearing cavity, and the other end of the connecting shaft is spaced from the inner end surface of the screw pump body cavity away from the Roots pump body cavity;

[0017] The screw rotor component close to one side of the Roots pump body cavity is installed on the connecting shaft, and a micro gap is formed between the other end and the end surface of the screw pump body cavity away from the Roots pump body cavity.

[0018] In the above technical solution, a middle partition is provided in the Roots pump body cavity, and the middle partition divides the Roots pump body cavity into a primary Roots pump body cavity and a secondary Roots pump body cavity arranged along the axial direction, and the secondary Roots pump body cavity is arranged between the primary Roots pump body cavity and the screw pump body cavity;

[0019] 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 body cavity, and the second-stage Roots rotor body is arranged in the second-stage Roots pump body cavity;

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

[0021] In the above technical solution, an intermediate connecting channel connecting the first-stage Roots pump body cavity and the second-stage Roots pump body cavity is provided in the pump body, and the connecting channel connects the second-stage Roots pump body cavity with the screw pump body cavity;

[0022] And / or, when the two first-stage Roots rotor bodies rotate, the fluid entering the air inlet is sent into the cavity of the second-stage Roots pump body through the intermediate connecting channel;

[0023] When the two secondary Roots rotor bodies rotate, the fluid sent from the intermediate connecting channel to the cavity of the secondary Roots pump body is sent to the cavity of the screw pump body through the connecting channel.

[0024] In the above technical solution, the pump body includes a primary pump body, a secondary pump body and a screw pump body, the primary pump body is sealedly connected to the secondary pump body, and the secondary pump body is sealedly connected to the screw pump body;

[0025] The first-stage Roots pump body cavity is arranged in the first-stage pump body, the second-stage Roots pump body cavity is arranged in the second-stage pump body, and the screw pump body cavity is arranged in the screw pump body;

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

[0027] In the above technical solution, the middle partition includes 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 first pump body and the second 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 connecting shaft through hole.

[0028] In the above technical solution, a notch communicating with the connecting channel is further provided on the outer wall of the pump body, and a sealing cover for sealing the notch is installed on the pump body;

[0029] And / or, a fluid processing component can be detachably installed in the connecting channel at the notch.

[0030] The above technical solution further comprises a driving device, which is installed on the pump body on the side away from the screw pump body cavity, and can drive one of the connecting shafts to rotate;

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

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

[0033] 1. In the utility model, the Roots pump and the screw pump are arranged on the same axis, and the same driving device can simultaneously drive the Roots pump and the screw pump to rotate to perform vacuuming. Compared with the previous structure in which the two motors are arranged up and down and are separated, the cost is lower, the space occupied is smaller, and the transportation cost can also be reduced;

[0034] 2. The utility model adopts a two-stage Roots pump and a screw pump, the Roots pump constitutes a booster pump, and the screw pump constitutes a vacuum pump, which can effectively improve the vacuuming efficiency and the vacuum effect;

[0035] 3. The utility model adopts a two-stage Roots pump in front of the screw pump, so that each stage of the Roots pump will generate compression, and the heat will not be too concentrated at the exhaust port of the screw pump, which can prevent the exhaust port temperature from being too high and causing the hydrocarbon mixture to coke and block, thereby ensuring the smoothness of vacuuming, preventing the screw pump from being damaged, reducing the maintenance rate, and extending the service life;

[0036] 4. In the utility model, air is firstly pumped through a two-stage Roots pump, which can effectively prevent dust and the like from entering the screw pump, prevent the occurrence of powder jamming and clogging, reduce the maintenance rate and extend the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of an embodiment of the utility model;

[0038] Figure 2 It is a cross-sectional structural schematic diagram of an embodiment of the utility model (the Roots pump is a two-stage Roots pump structure);

[0039] Figure 3 yes Figure 2 A partial enlarged view of the connection between the middle screw rotor component and the coupling shaft;

[0040] Figure 4 It is a gas flow path diagram in one embodiment of the utility model (the Roots pump is a two-stage Roots pump structure, the connecting channel is arranged above the pump body, and there is no notch communicating with the connecting channel);

[0041] Figure 5 It is a structural schematic diagram of a Roots rotor component in an embodiment of the utility model in a state of being connected to a coupling shaft (the Roots rotor component includes a primary Roots rotor body and a secondary Roots rotor body);

[0042] Figure 6 yes Figure 2 A schematic diagram of the end surface structure of the connection between the middle partition and the connecting shaft;

[0043] Figure 7 This is a flow path diagram of the airflow in another embodiment of the utility model (the Roots pump body cavity is a single cavity structure, and the connecting channel is arranged at the bottom of the pump body);

[0044] Figure 8 This is a schematic structural diagram of a Roots rotor component in a working state in an embodiment of the utility model;

[0045] Fig. 9 It is a structural schematic diagram of the connecting channel in another embodiment of the utility model (a structure in which a notch is provided on the pump body).

[0046] Among them: 1. Pump body; 2. Coupling 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. Step hole; 11. Spline; 12. Step stopper; 13. Sealing cover; 14. First bearing cavity; 15. Second bearing cavity; 16. Bearing; 17. Middle partition; 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 Sub-body; 22. Middle connecting channel; 23. Primary pump body; 24. Secondary 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. Coupling hole; 34. Driving device; 35. Gear; 36. Gear housing; 37. Sealing plate; 38. Left connecting channel; 39. Right connecting channel; 40. Connecting chamber. DETAILED DESCRIPTION

[0047] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0048] Example 1: See Figures 1 to 9 As shown, a two-axis mixing pump includes a pump body 1 and two connecting shafts 2 that are parallel to each other and rotatably installed in the pump body 1; the two connecting shafts 2 are arranged with a front-to-back spacing (the position direction in the figure, the above, down, left and right directions below, are all taken as an example).

[0049] The pump body 1 is provided with a mutually independent Roots pump body cavity 3 and a screw pump body cavity 4 along the axial direction of the connecting shaft 2. The connecting shaft 2 is rotatably connected to 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 to the right and left sides of the Roots pump body cavity 3, respectively, and the connection is sealed and rotatably connected (such as an oil seal), so that the Roots pump body cavity 3 and the screw pump body cavity 4 are independent of each other, and the two will not be connected from the connection between the connecting shaft 2 and the pump body 1.

[0050] See also Figure 2 , 4As shown, the pump body 1 is provided with an air inlet 5, an air outlet 6 and a connecting channel 7. The air inlet 5 connects the Roots pump body cavity 3 with the outside atmosphere, the air outlet 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 this embodiment, taking the position shown in the figure as an example, the bottom of the pump body 1 is used for installation and fixing, the air inlet 5 is arranged at the top of the pump body 1, which is communicated with the top of the Roots pump body cavity 3, the exhaust port 6 is arranged at the right end of the pump body 1, which is communicated with the right end of the screw pump body cavity 4, and the connecting channel 7 is arranged at the bottom of the pump body 1 (when the Roots pump body cavity is a single cavity, see Figure 7 , Figure 8 ), used to connect the Roots pump body cavity 3 and the screw pump body cavity 4.

[0052] See also Figure 2 , 3 As shown in , 5, two mutually meshing Roots rotor components 8 are provided in the Roots pump body cavity 3, and the two Roots rotor components 8 are respectively mounted on the two connecting shafts 2. When the two Roots rotor components 8 rotate, the fluid entering from the air inlet 5 is sent into the screw pump body cavity 4 through the connecting channel 7;

[0053] Two mutually meshing screw rotor components 9 are provided in the screw pump body cavity 4. The two screw rotor components 9 are respectively installed on the two connecting shafts 2. When the two screw rotor components 9 rotate, the fluid sent into the screw pump body cavity 4 through the connecting channel 7 is discharged from the exhaust port 6.

[0054] In the present embodiment, the Roots pump body cavity is a quasi-"∞"-shaped cavity (a transversely arranged 8-shaped structure), which is composed of two cylindrical cavities whose inner ends are interconnected, and the two connecting shafts are coaxially arranged with the two cylindrical cavities respectively. The Roots rotor component is also a quasi-"∞"-shaped structure (a transversely arranged 8-shaped structure), and its opposite outer surfaces at both ends are in contact with the inner wall of the Roots pump body cavity, or there is a micro gap between its opposite outer surfaces at both ends and the inner wall of the Roots pump body cavity (preferably there is a micro gap to ensure that the Roots rotor component will not contact and scratch the inner wall of the Roots pump body cavity when rotating), and the two connecting shafts rotate in opposite directions, and their tops rotate toward the inner ends. Since the two Roots rotor components are meshed with each other, the Roots pump body cavity above the two Roots rotor components is an independent space, and the Roots rotor component below The Roots pump body cavity on the other side is another independent space, so that when the two connecting shafts rotate, the external fluid (gas) is pressed into the space below the Roots rotor component from the air inlet, and then sent to the left end of the screw pump body cavity through the connecting channel, wherein there is a micro-gap between the outer surfaces of the two screw rotor components and the inner surface of the screw pump body cavity on the corresponding side, and the outer surface of the screw rotor component has a spiral groove (spiral exhaust groove), the groove width of the spiral groove gradually decreases from left to right, and the screw rotor component beside the spiral groove will mesh with the spiral groove of the adjacent screw rotor component (and there is a gap between the two and they will not contact each other), so that the fluid sent into the screw pump body cavity through the connecting channel is discharged to the right through the gap of the spiral groove and sent out through the exhaust port, thereby realizing the vacuum pumping action.

[0055] In this embodiment, the Roots pump body cavity and the Roots rotor component constitute the Roots pump, the screw pump body cavity and the screw rotor component constitute the screw pump, and the Roots rotor component and the screw rotor component are installed on the same connecting shaft, that is, the screw pump and the Roots pump are arranged on the same axis, so that the same driving device can simultaneously drive the Roots pump and the screw pump to work at the same time, which can reduce space occupancy, reduce transportation and installation costs, and at the same time, the cost will be lower.

[0056] See also Figure 2 , 3As shown, in this 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. The diameter of the left hole matches the outer diameter of the coupling shaft. The right end of the coupling shaft has a screw hole. The outer surface of the coupling shaft in the screw pump body cavity has a keyway, and the left hole is also provided with a keyway. The coupling shaft 2 and the screw rotor component 9 are connected by a spline 11. The inner end of the spline 11 is stuck in the keyway of the coupling shaft 2, and the outer end of the spline is stuck in the keyway of the left hole, thereby realizing the circumferential limit between the screw rotor component and the coupling shaft to prevent the two from rotating relative to each other. A stepped stopper 12 is installed in the right hole, the left side of the middle part of the stepped stopper abuts against the left end face of the right hole, and the left end of the stepped stopper abuts against the right side face of the coupling shaft, and then the bolt passes through the stepped stopper and the screw hole at the right end of the coupling shaft to connect, thereby axially fixing the screw rotor component and the coupling shaft to prevent the two from axially moving away from each other. Furthermore, a sealing cover 13 is installed at the right end of the screw rotor component 9, and the sealing cover 13 seals the right end of the right hole, which can prevent gas from entering the right hole and ensure the vacuum effect.

[0057] At the same time, in the utility model, the right end of the connecting shaft and the right end of the screw pump body cavity will not be connected, and there is an axial spacing, that is, the right end of the connecting shaft and the screw rotor component are a cantilever screw structure (the left end of the screw rotor component will be supported by the rotating connection between the connecting shaft and the pump body, and the right end will not be limited, that is, a cantilever structure). This structure is convenient for debugging during the assembly process and adjusting the spacing between the two screw rotor components to ensure the meshing between the two. The two screw rotor components will not contact, but there is only a slight gap between them, and they will not rub against each other, thereby ensuring the quality of vacuum extraction.

[0058] The Roots rotor component and the connecting shaft are an integrated structure, which can effectively ensure the coaxiality.

[0059] See also Figure 2 As shown, a first bearing cavity 14 and a second bearing cavity 15 are further provided in the pump body 1. 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 outside the Roots pump body cavity 3, and the second bearing cavity 15 is located on the right side outside the Roots pump body cavity 3, that is, the second bearing cavity 15 is located in the screw pump body cavity 4.

[0060] See also Figure 2 As shown, two bearings 16 are installed in the first bearing cavity 14 and the second bearing cavity 15 respectively, and the left end of the connecting shaft 2 extends into the first bearing cavity 14 and is rotatably connected to the pump body 1 through the bearings 16 in the first bearing cavity 14;

[0061] The right end of the coupling 2 extends to the second bearing cavity 15 and is inserted into the screw pump body cavity 4, and the coupling 2 arranged in the second bearing cavity 15 is rotatably connected to the pump body 1 via the bearing 16. The coupling is rotatably connected to the body through the bearing to ensure smoothness and stability of rotation. Among them, an oil seal (or other sealing member) is provided at the connection between the coupling and the body, which can achieve a sealing effect and prevent the occurrence of air leakage. At the same time, the left end of the screw rotor component abuts against the outer ring of the bearing in the second bearing cavity to limit the axial movement of the screw rotor component close to the Roots rotor component, and the step limiter is used to limit the axial movement of the screw rotor component away from the Roots rotor component.

[0062] See also Figure 2 As shown, the left end of the coupling 2 is connected to the bearing 16 in the first bearing cavity 15, there is a gap between the right end of the coupling 2 and the right end surface of the screw pump body cavity 4, and there is a gap between the right end of the coupling 2 and the right end of the screw rotor component 9.

[0063] The left end of the screw rotor component is installed on the connecting shaft, and there is a micro gap between the right end of the screw rotor component and the right end surface of the screw pump body cavity. In this way, when the connecting shaft drives the screw rotor component to rotate, the screw rotor component will not contact the inner wall of the screw pump body cavity to generate friction, thereby preventing damage.

[0064] See also Figure 2 , 4 As shown in , 6, a middle partition plate 17 is provided in the Roots pump body cavity 3, and the middle partition plate 17 divides the Roots pump body cavity 3 into a primary Roots pump body cavity 18 and a secondary Roots pump body cavity 19 arranged along the axial direction, and the secondary Roots pump body cavity 19 is arranged between the primary Roots pump body cavity 18 and the screw pump body cavity 4;

[0065] The Roots rotor component 8 includes a primary Roots rotor body 20 and a secondary Roots rotor body 21 which are arranged at intervals. The primary Roots rotor body 20 is arranged in the primary Roots pump body cavity 18, and the secondary Roots rotor body 21 is arranged in the secondary Roots pump body cavity 19;

[0066] Two connecting shaft through holes 33 are provided on the middle partition plate 17 , and the middle portion of each connecting shaft 2 is located in one of the connecting shaft through holes 33 .

[0067] An intermediate connecting passage 22 connecting the primary Roots pump body cavity 18 and the secondary Roots pump body cavity 19 is provided in the pump body 1 , and the connecting passage 7 connects the secondary Roots pump body cavity 19 and the screw pump body cavity 4 .

[0068] When the two primary Roots rotor bodies 20 rotate, the fluid entering the air inlet 5 is sent into the secondary Roots pump body cavity 19 through the intermediate connecting channel 22;

[0069] When the two secondary Roots rotor bodies 21 rotate, the fluid in the secondary Roots pump body cavity 19 is delivered through the intermediate connecting channel 22 , and then delivered into the screw pump body cavity 4 through the connecting channel 7 .

[0070] In the present embodiment, the Roots pump adopts a two-stage Roots pump. Since the corresponding connecting shafts in the first-stage Roots pump body cavity and the second-stage Roots pump body cavity have the same rotation direction, the first-stage Roots rotor body and the second-stage Roots rotor body have the same rotation direction. The two first-stage Roots rotor bodies drive the gas to flow from top to bottom, and the second-stage Roots rotor body also drives the gas to flow from top to bottom. Therefore, the structure of the two-stage Roots pump is that the middle connecting channel is arranged around the second-stage Roots pump body cavity, the bottom of which is the fluid inlet, and the top is the fluid outlet. The left end of the fluid inlet is connected to the bottom of the first-stage pump body cavity, and the right end is connected to the top of the second-stage Roots pump body cavity. The connecting channel is arranged at the bottom of the pump body, the left end of the connecting channel is connected to the bottom of the second-stage Roots pump body cavity, and the right end of the connecting channel is connected to the left end of the screw pump body cavity. In this way, when working, the connecting shaft will drive the two connecting shafts to rotate at the same time, that is, the first-stage Roots rotor body and the second-stage Roots rotor body to rotate at the same time. The two first-stage Roots rotor bodies draw the gas at the air inlet into the first-stage Roots pump body cavity below the first-stage Roots rotor body (primary compression), and send the gas into the second-stage Roots pump body cavity above the second-stage Roots rotor body through the middle connecting channel. At the same time, the second-stage Roots rotor body draws the gas above it into the second-stage Roots pump body cavity below the second-stage Roots rotor body, and sends it into the screw pump body cavity through the connecting channel (secondary compression), and discharges the gas from the exhaust port through the screw rotor component, thereby realizing the vacuum pumping action.

[0071] In this embodiment, the Roots pump adopts a two-stage Roots pump, which can realize two-stage compression in a limited space, improve vacuum degree and vacuum efficiency, reduce space occupation, reduce energy consumption, and save costs. At the same time, the heat generated by the first-stage Roots rotor body in the process of vacuuming and compressing the gas can be dissipated in advance, which can effectively prevent the temperature of the rear end screw rotor component from being high, and can effectively prevent the high temperature from damaging the screw rotor component. In addition, the temperature of the screw rotor component is lower, and it is not easy to cause the coking phenomenon of hydrocarbon mixture (high temperature is prone to coking of hydrocarbon mixture and clogging), and the problem of clogging at the screw rotor component affecting vacuuming is prevented, so as to ensure the stability of vacuuming, reduce the temperature of the exhaust port, reduce the maintenance rate, and extend the service life. When a two-stage Roots vacuum pump is used to process the process medium, since the performance of the secondary pump can form a different compression ratio for the primary pump, after calculating and designing a range of compression ratio values, the temperature of the process medium discharged from the primary Roots pump body cavity can reach a higher and more stable temperature and enter the secondary Roots pump body cavity. The process medium is further compressed in the secondary Roots pump body cavity, which is convenient for subsequent screw pump rotor components to be sucked, and the vacuum degree is further improved. Since the intermediate connecting channel in this embodiment just covers the outside of the entire secondary Roots pump body cavity, that is, the intermediate connecting channel covers a large area, it is convenient for heat dissipation.

[0072] At the same time, the gas in the first-stage Roots pump body cavity can be directly sent into the second-stage Roots pump body cavity through the middle connecting channel, and the gas in the second-stage Roots pump body cavity can be directly sent into the screw pump body cavity through the connecting channel, and the vacuum flow channel is relatively short. In addition, the connecting channel and the middle connecting channel can be set wider to facilitate heat dissipation. At the same time, when vacuuming the air with dust, it is not easy to get stuck. In this embodiment, the Roots rotor component is located on the side (left side) of the screw rotor component, and the Roots rotor component also acts as a balancing weight block for the screw rotor component, which is used to balance the force of the screw rotor component, so that the screw rotor component is a cantilever screw structure, which is convenient for assembly and debugging, and reduces the difficulty of assembly. At the same time, with a two-stage Roots pump, the Roots pump not only acts as a vacuum pump, but also acts as a booster pump, thereby improving the vacuum efficiency.

[0073] Among them, in the utility model, the dry screw pump composed of two screw rotor parts and the screw pump body cavity is a non-wet structure, that is, no lubricant needs to be added inside. In this way, it 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, that is, the Roots pump is used for two-stage compression and pressurization. In this way, when the gas with dust enters the first level between the adjacent screw rotor parts of the screw pump body cavity, due to the absence of lubricant, it is not easy for dust to stick to the lubricant and cause blockage. In addition, the air flow pressure entering the screw pump body cavity is high, and the dust is discharged quickly. Even if blockage occurs, it can extend the normal use time and reduce the frequency of cleaning and maintenance.

[0074] In this utility model, see Figure 2 , 4 As shown, the pump body 1 is a split structure, and the pump body 1 includes a primary pump body 23, a secondary pump body 24 and a screw pump body 25. The primary pump body 23 is sealedly connected to the secondary pump body 24, and the secondary pump body 24 is sealedly connected to the screw pump body 25;

[0075] The first-stage Roots pump body cavity 18 is arranged in the first-stage pump body 23 and is connected to the right end face of the first-stage pump body 23; the second-stage Roots pump body cavity 19 is arranged in the second-stage pump body 24 and is connected to the left end face of the second-stage pump body 24; the screw pump body cavity 4 is arranged in the screw pump body 25 and is connected to the left end face of the screw pump body 25.

[0076] The middle partition plate 17 is disposed at the connection between the primary pump body 23 and the secondary pump body 24 .

[0077] A circumferentially arranged left-side concave cavity will be set on the right end face of the primary pump body, and the inner end of the left-side concave cavity is connected to the primary pump body cavity. A right-side concave cavity is set on the left end face of the secondary pump body, and the inner end of the right-side concave cavity is connected to the secondary pump body cavity. When the pump body is assembled, the right end face of the primary pump body contacts the left end face of the secondary pump body and is locked by bolts. The left-side concave cavity will be set opposite the right-side concave cavity, and the outer edge of the middle partition will be inserted into the secondary concave cavity and the right groove to limit the partition. In order to ensure sealing, a sealing gasket will be set at the connection between the primary pump body and the secondary pump body to prevent air leakage. When assembling the screw pump body, the left end face of the screw pump body contacts the right end face of the secondary pump body, and then it is locked with bolts. A sealing ring will also be set at the connection between the screw pump body and the secondary pump body to prevent air leakage and ensure the sealing effect.

[0078] Among them, a part of the connecting channel will be on the secondary pump body, and the other part will be on the screw pump body, and the two are arranged oppositely. After the secondary pump body and the screw pump body are sealed and connected, a complete connecting channel is formed; preferably, the connecting channel 7 will include a left connecting channel 26 and a right connecting channel 27, the left end of the left connecting channel is connected to the secondary Roots pump body cavity, and the right end is connected to the right end bottom surface of the secondary pump body (in this embodiment, it is connected to the right end surface of the secondary pump body, see Figure 4 As shown), the right end of the right connecting channel is connected to the cavity of the screw pump body, and the left end is connected to the bottom surface of the left end of the screw pump body (in this embodiment, it is connected to 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 connected to the left end of the right connecting channel, and the connection is sealed to form a complete connecting channel, so as to realize the connection between the secondary Roots pump body cavity and the screw pump body cavity. Similarly, a part of the middle 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 sealed and connected, a complete middle connecting channel is formed. Preferably, the middle connecting channel 22 will include a left middle connecting channel 28 and a right middle connecting channel 29. The left end of the left middle connecting channel is connected to the bottom of the primary Roots pump body cavity, and the right end is connected to the bottom surface of the right end of the primary pump body. The right middle connecting channel surrounds the outside of the secondary Roots pump body cavity, and the right end of the right middle connecting channel is connected to the top of the secondary Roots pump body cavity, and the left end is connected to the bottom surface of the left end of the secondary pump body. See Figure 4 After the secondary pump body and the primary pump body are connected, the right end of the left intermediate connecting channel is connected to the left end of the right intermediate connecting channel, and the connection is sealed to form a completed intermediate connecting channel, so as to realize the connection between the primary Roots pump body cavity and the secondary Roots pump body cavity.

[0079] See also Figure 2 , 6 As shown, the middle partition 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 with each other, and the opposite ends of the first plate body 30 and the second plate body 31 are respectively provided with grooves 32 to form the connecting shaft through hole 33.

[0080] In this way, when the middle partition is assembled, the upper and lower clamping methods are directly adopted, so that the grooves of the first plate body and the second plate body are respectively clamped into the top and bottom of the coupling shaft between the first-stage rotor component and the second-stage rotor component, thereby separating the Roots pump body cavity into two independent first-stage Roots pump body cavities and second-stage Roots pump body cavities. Among them, an oil seal or other sealing member will be set at the connection between the coupling shaft through hole and the coupling shaft to achieve sealing, so that there will be no leakage between the first-stage Roots pump body cavity and the second-stage Roots pump body cavity from the coupling shaft through hole. Of course, it is also possible not to set a seal member, so that there is a micro gap between the coupling shaft through hole and the coupling shaft, so that the micro gap connects the first-stage Roots pump body cavity and the second-stage Roots pump body cavity, and will not affect the vacuum effect.

[0081] See also Figure 1 , 2 As shown, it also includes a driving device 34, which is installed on the pump body 1 on the side away from the screw pump body cavity 4, and the driving device 34 can drive one of the connecting shafts 2 to rotate;

[0082] A gear 35 is provided at the left end of the coupling 2, and the gears 35 at the ends of the two couplings 2 are meshed. The driving device 34 drives one of the gears 35 and the coupling 2 to rotate, and drives the other coupling 2 to rotate via the other gear 35. Among them, the driving device adopts a motor, or a combination of a motor and a reducer. In this embodiment, the driving device adopts a motor as an example. The output shaft of the motor has a gear on it, and the gear will mesh with a gear on a coupling. In this way, when the motor is working, it drives the two couplings to rotate at the same time, and the rotation directions of the two couplings are opposite. When the two couplings rotate, 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 to perform a vacuum pumping action. In other words, the output shaft of the motor is directly connected to the gear at the end of a coupling, so as to drive the two couplings to rotate at the same time. In this embodiment, see Figure 2 As shown, the motor is directly connected to the gear at the end of a coupling shaft, which can reduce the space occupied. In this way, the same motor can be used for driving, which is more cost-effective, has lower energy consumption, and is easier to install.

[0083] In the utility model, there is no need to set up a frame 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] Furthermore, in the present invention, the first bearing cavity is arranged on the first-stage pump body on the opposite side away from the first-stage Roots pump body cavity, that is, the first bearing cavity is arranged on the first-stage pump body and is connected to the left end face of the first-stage pump body. There will be a hole connecting the first bearing cavity and the first-stage Roots pump body cavity for the connecting shaft to penetrate into the first bearing cavity and the first-stage Roots pump body cavity, and an oil seal will be arranged in the hole to prevent air leakage, or other sealing members may be arranged. Among them, a gear housing 36 will be installed at the left end of the first-stage pump body 23, and the right end of the gear housing 36 has a gear cavity 37. The right end of the gear housing 36 is connected to the left end of the first-stage pump body 23, and the gear at the left end of the connecting shaft 2 will be in the gear cavity. Then the driving device is installed on the left side of the gear housing, and the right end of the driving device is inserted into the gear cavity and meshes or connects with one of the gears. In this embodiment, the right end of the driving device is directly connected to a gear, see Figure 2 shown.

[0085] Furthermore, since the bearings are prone to high temperatures when working for a long time, a cooling chamber is provided in the primary pump body outside the first bearing cavity (not shown in the figure), and a cooling chamber is also provided in the secondary pump body outside the second bearing cavity. The cooling chamber is wrapped around the outside of the corresponding bearing cavity, and a liquid inlet pipe and a liquid outlet pipe are provided on the two cooling chambers to communicate with the cooling chamber, respectively. The liquid inlet pipe is used for delivering the cooling medium, and the liquid outlet pipe is used for delivering the cooling medium. The cooling medium is introduced into the cooling chamber to cool the bearing, thereby preventing the bearing and the coupling from generating high temperatures and deformation, ensuring the coaxiality of the coupling, thereby ensuring the mutual coordination relationship between the Roots rotor components and the screw rotor components during rotation, and the coordination relationship with the corresponding Roots pump body cavity and the screw pump body cavity, preventing the phenomenon of stagnation, and also preventing the Roots pump body cavity, the screw pump body cavity, the Roots rotor components and the scratches of the screw rotor components, ensuring the vacuum degree, reducing the maintenance rate and extending the service life.

[0086] Among them, the bearing will preferably adopt a single-row angular contact bearing. When the bearing and the coupling are installed, bearing seats are respectively arranged at the left and right ends of the bearing, and the outer steel ring of the bearing is clamped by the bearing seat. At the same time, gaskets can be added during assembly. The gaskets are arranged between the bearing seat and the outer steel ring to adjust the position of the bearing, thereby fine-tuning the coupling to adjust the gap between the Roots rotor components and the Roots pump body cavity to prevent sticking.

[0087] In another embodiment, see Fig. 9 As shown, a notch communicating with the connecting channel 7 is further provided on the outer wall of the pump body 1, and a sealing cover 37 is installed on the pump body 1 to seal the notch;

[0088] A fluid processing component can be detachably installed in the connecting channel at the notch.

[0089] Among them, in this embodiment, the connecting channel 7 will include a left connecting channel 38 and a right connecting channel 39. The left end of the left connecting channel 38 is connected to the secondary Roots pump body cavity 19, and the other end is connected to the bottom of the right end surface of the secondary pump body 24. The right end of the right connecting channel 39 is connected to the screw pump body cavity 4, and the other end is connected to the bottom of the left end surface 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, a sealing plate or a fluid handling 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 handling component has a connecting cavity 40, which covers the outside of the outlet and the inlet, and then the two ends of the sealing plate 37 are respectively locked to the outside of the secondary pump body 24 and the screw pump body 25, so that the inlet and the outlet are connected, so that the connecting cavity, the left connecting channel and the right connecting channel constitute a complete connecting channel. Preferably, the notch is set on the side wall of the pump body, not on the bottom, so that it is easy to install and remove the sealing plate.

[0091] In this way, the side of the connecting channel can be directly connected to the outer wall of the pump body, which makes it easy for the operator to directly open the sealing cover or the fluid handling component to expose the connecting channel. The operator can observe the internal conditions of the Roots pump body cavity and the screw pump body cavity through the connecting channel. In this way, a simple query can be made without major disassembly, and targeted disassembly and maintenance can be carried out. At the same time, the internal conditions can also be observed during assembly and debugging, which is convenient for debugging.

[0092] Furthermore, fluid processing components such as filters, alkali bags, coolers or heaters can be installed in the connecting cavity. For example, a filter can be installed to filter dust and other substances that need to enter the screw pump body cavity to prevent dust from blocking the gap between the screw rotor components, or blocking the gap between the screw rotor components and the screw pump body cavity. The alkali bag is used to adsorb water vapor, the cooler is used to cool the air, the heater is used to heat the air, or other mechanisms can be added according to the actual functions required to solve the corresponding problems.

[0093] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0094] In the present utility model, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection, or an integral one; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, for example, the two can form a mechanical abutment or abutment connection through abutment, contact, etc., the two can also be directly hung or hung through an intermediate medium, etc., or it can be the internal connection of the two elements or the interaction relationship between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.

Claims

1. A two-shaft mixing pump, characterized in that: It comprises a pump body and two connecting shafts which are parallel to each other and rotatably installed in the pump body; The pump body is provided with mutually independent Roots pump body cavities and screw pump body cavities along the axial direction of the connecting shaft, the connecting shaft is rotatably connected with both ends of the Roots pump body cavity, and the other end of the connecting shaft is inserted into the screw pump body cavity; The pump body is provided with an air inlet, an air outlet and a connecting channel, the air inlet connects the Roots pump body cavity with the outside atmosphere, the air outlet connects the screw pump body cavity with the outside atmosphere, and the connecting channel connects the Roots pump body cavity with the screw pump body cavity; Two mutually meshing Roots rotor components are arranged in the Roots pump body cavity, and the two Roots rotor components are respectively mounted on the two connecting shafts. When the two Roots rotor components rotate, the fluid entering from the air inlet is sent into the screw pump body cavity through the connecting channel; Two mutually meshing screw rotor components are arranged in the screw pump body cavity, and the two screw rotor components are respectively mounted on the two connecting shafts. When the two screw rotor components rotate, the fluid sent into the screw pump body cavity through the connecting channel is discharged from the exhaust port.

2. The two-shaft mixing pump according to claim 1, characterized in that: The Roots rotor component and the connecting shaft are an integrated structure.

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

4. The two-shaft mixing pump according to claim 3, characterized in that: One end of the coupling shaft is connected to the bearing in the first bearing cavity, and the other end of the coupling shaft is spaced from an inner end surface of the screw pump cavity away from the Roots pump cavity. The screw rotor component close to one side of the Roots pump body cavity is installed on the connecting shaft, and a micro gap is formed between the other end and the end surface of the screw pump body cavity away from the Roots pump body cavity.

5. The two-shaft mixing pump according to claim 1, characterized in that: A middle partition is provided in the Roots pump body cavity, and the middle partition divides the Roots pump body cavity into a primary Roots pump body cavity and a secondary Roots pump body cavity arranged along the axial direction, and the secondary Roots pump body cavity is arranged between the primary Roots pump body cavity and the screw pump body 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 body cavity, and the second-stage Roots rotor body is arranged in the second-stage Roots pump body cavity; The middle partition plate is provided with two connecting shaft through holes, and the middle part of each connecting shaft is located in one of the connecting shaft through holes.

6. The two-shaft mixing pump according to claim 5, characterized in that: An intermediate connecting channel connecting the primary Roots pump body cavity and the secondary Roots pump body cavity is provided in the pump body, and the connecting channel connects the secondary Roots pump body cavity with the screw pump body cavity; And / or, when the two first-stage Roots rotor bodies rotate, the fluid entering the air inlet is sent into the cavity of the second-stage Roots pump body through the intermediate connecting channel; When the two secondary Roots rotor bodies rotate, the fluid sent from the intermediate connecting channel to the cavity of the secondary Roots pump body is sent to the cavity of the screw pump body through the connecting channel.

7. The two-shaft mixing pump according to claim 5, characterized in that: The pump body comprises a primary pump body, a secondary pump body and a screw pump body, the primary pump body is sealedly connected to the secondary pump body, and the secondary pump body is sealedly connected to the screw pump body; The first-stage Roots pump body cavity is arranged in the first-stage pump body, the second-stage Roots pump body cavity is arranged in the second-stage pump body, and the screw pump body cavity is arranged in the screw pump body; And / or, the middle partition is arranged at the connection between the primary pump body and the secondary pump body.

8. The two-shaft mixing pump according to claim 7, characterized in that: The middle partition includes 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 connecting shaft through hole.

9. The two-shaft mixing pump according to claim 1, characterized in that: The outer wall of the pump body is also provided with a notch communicating with the connecting channel, and a sealing cover for sealing the notch is installed on the pump body; And / or, a fluid processing component can be detachably installed in the connecting channel at the notch.

10. The two-shaft mixing pump according to claim 1, characterized in that: It also includes a driving device, which is installed on the pump body on the side away from the screw pump body cavity, and can drive one of the connecting shafts to rotate; And / or, a gear is provided at the end of the connecting shaft away from the screw pump body cavity, the gears at the two ends of the connecting shaft are meshed, the driving device drives one of the gears and the connecting shaft to rotate, and drives the other connecting shaft to rotate through another gear.

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