Magnetic drive type leakage-free integral double-screw pump

Abstract

The invention discloses a magnetic drive type leakage-free integral double-screw pump, which relates to the technical field of rotating equipment, and comprises a pump body, a bushing mounted on the pump body, a driving screw and a driven screw which are meshed with each other and are arranged in the bushing in parallel, and a magnetic driver connected with the second end of the driving screw, the driving screw is axially positioned through the positioning bearing, the magnetic driver forms a sealing cavity at the second end of the driving screw, the first end of the driving screw and the first end of the driven screw form an axial positioning cavity in the pump body, and an inlet cavity is formed in the position, on the inlet flange side of the pump body, of the lining. An outlet cavity is formed in the position, on the outlet flange side of the pump body, of the lining, pressure difference exists between the inlet cavity and the outlet cavity, and the magnetic driver is connected with a prime motor. The double-screw pump with the structural form has intrinsic safety and wide adaptability under the complex working conditions of high temperature, high pressure, high viscosity and multiphase (gas-solid-liquid) mixed transportation of flammable and explosive dangerous media.

Description

Technical Field

[0001] The invention relates to the technical field of rotating equipment, in particular to a magnetically driven, leak-free, integral twin-screw pump. Background Art

[0002] In recent years, my country's new materials industry has accelerated its development. The new materials industry has penetrated into all areas of the national economy, national defense construction and social life, and plays a vital role in the development of the national economy.

[0003] Our country's new materials industry started late, and the main producers of new materials in the world are large multinational companies. In the increasingly complex international situation, we are facing technological blockades in both production technology and key equipment.

[0004] Twin-screw pumps are widely used in the new materials industry due to their good adaptability to working conditions, such as polymer reactor circulation pumps for VAE elastomer units; norbornene loop reactor circulation pumps; elastic polyolefin loop reactor circulation pumps; elastic polyolefin external heat circulation pumps; and rubber industry solution polymerization external heat circulation pumps.

[0005] The shaft seal type of twin-screw pump is divided into mechanical seal and no seal. At present, the twin-screw pump in the industry adopts mechanical seal. This pump structure has the following disadvantages:

[0006] (1) The sealing system design is complex. Due to the structural limitations of the twin-screw pump, one pump must use four sets of mechanical seals, a double-end or triple-end structure, and a flushing water station. The overall size is large and the operation and maintenance costs are high. It is difficult to choose the seal flushing liquid. For example, the medium n-hexane is extremely flammable, and its steam and air will form an explosive mixture. It will react violently with oxidants and even cause combustion. Poor reliability. Mechanical seals are consumable parts. Once damaged without appropriate countermeasures, it is easy to cause major safety accidents.

[0007] (2) Expensive procurement and maintenance costs. The seals must be imported, and the investment in seals is close to 50% of the total price.

[0008] Sealless twin screw pumps have the following advantages:

[0009] (1) Suitable for media containing solid particles or fibers, as these media may damage mechanical seals;

[0010] (2) The seal-free design reduces the complexity of the pump structure and improves reliability, especially when handling viscous or abrasive media. This pump has a strong self-priming ability and can meet the requirements of mixed transportation of gas, solid and liquid;

[0011] (3) Having a smaller required NPSH;

[0012] (4) Excellent magnetic circuit design, suitable for transmitting large torque loads;

[0013] (5) Compared with twin-screw pumps with mechanical seal design, procurement and maintenance costs are greatly reduced.

[0014] However, the design and manufacturing technology threshold of sealless twin-screw pumps is very high. Currently, there are only small-parameter design solutions in the world, and domestic manufacturers do not have the design, production and application capabilities of this type of pump.

[0015] In summary, how to effectively design a seal-less twin-screw pump with intrinsic safety characteristics is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0016] The purpose of the present invention is to provide a magnetically driven, leak-free, integral twin-screw pump, which has intrinsic safety and good adaptability under complex working conditions.

[0017] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0018] A magnetically driven, leak-free, integral twin-screw pump comprises a pump body, a bushing mounted on the pump body, a driving screw and a driven screw meshing with each other and arranged in parallel in the bushing, and a magnetic transmission connected to the second end of the driving screw, wherein the driving screw is axially positioned by a positioning bearing, the magnetic transmission forms a sealed chamber at the second end of the driving screw, the first ends of the driving screw and the driven screw form an axial positioning chamber in the pump body, the bushing is provided with an inlet chamber on the inlet flange side of the pump body, the bushing is provided with an outlet chamber on the outlet flange side of the pump body, there is a pressure difference between the inlet chamber and the outlet chamber, and the magnetic transmission is connected to a prime mover.

[0019] Optionally, the magnetic transmission includes an inner magnetic cylinder assembly connected to the second end of the driving screw, an outer magnetic cylinder assembly connected to the first end of the transmission shaft and cooperating with the inner magnetic cylinder assembly, and an isolation sleeve connected to the second end of the pump body through a connecting plate, the isolation sleeve wraps the inner magnetic cylinder assembly and forms the sealed chamber, and there are gaps between the inner wall and the outer wall of the isolation sleeve and the inner magnetic cylinder assembly and the outer magnetic cylinder assembly, respectively.

[0020] Optionally, the inner bottom surface of the isolation sleeve is a convex surface protruding toward the inner magnetic cylinder assembly.

[0021] Optionally, the inner bottom surface of the isolation sleeve gradually bulges from the outer circumference to the center, and the inner bottom surface of the isolation sleeve is connected to the inner wall through a rounded corner.

[0022] Optionally, the transmission shaft is arranged in a bearing seat, both ends of the transmission shaft are supported by transmission bearings, and the second end of the transmission shaft extends out of the bearing seat and is connected to the prime mover;

[0023] It also includes a protective cover connecting the bearing seat and the connecting plate, and the protective cover is arranged on the outer periphery of the outer magnetic cylinder assembly.

[0024] Optionally, a temperature sensor for detecting the temperature inside the pump body is provided on the isolation sleeve, and the temperature sensor is connected to the start switch of the twin-screw pump. When the current temperature inside the pump body detected by the temperature sensor is greater than or equal to a set temperature, the twin-screw pump stops.

[0025] Optionally, the first end of the driving screw rod has a concave wheel, the first end of the driven screw rod is provided with a convex wheel, the convex wheel is embedded in the concave wheel, and the convex wheel and the concave wheel form the axial positioning chamber in the pump body.

[0026] Optionally, a rear end cover is provided at the first end of the pump body, a front end cover is provided at the second end of the pump body, the connecting plate is arranged on the second side of the front end cover, and sliding sleeves are provided in the openings at both ends of the bushing, and the sliding sleeves are used to radially support the driving screw and the driven screw.

[0027] Optionally, a sleeve pressing ring is provided on the first side of the bushing, and the sleeve pressing ring and the front end cover are provided with a stepped hole on the side close to the sliding sleeve, the sliding sleeve on the first side abuts against the stepped hole of the sleeve pressing ring, the locating bearing is arranged in the stepped hole of the front end cover, the depth of the stepped hole of the front end cover is greater than the length of the sliding sleeve, and the sliding sleeve on the second side abuts against the locating bearing.

[0028] Optionally, the pump body is a double-layer pump body with a heat-insulating chamber.

[0029] In the magnetically driven, leak-free, integral twin-screw pump provided by the present invention, the material enters the inlet chamber through the flange, is gradually pressurized under the meshing conveyance of the driving screw and the driven screw, enters the outlet chamber, and is finally conveyed to the outside of the pump through the flange. There is a pressure difference between the inlet chamber and the outlet chamber, and part of the material enters the sealed chamber through the gap between the bushing on the second side and the driving screw and the driven screw, passes through the gap of the magnetic transmission, and finally returns to the inlet chamber through the connecting hole in the driving screw. There is a pressure difference between the inlet chamber and the outlet chamber, and part of the material enters the axial positioning chamber through the connecting hole in the bushing, and returns to the inlet chamber through the gap between the bushing on the left side and the driving screw and the driven screw.

[0030] The material circulates in the pump, which can ensure that the positioning components and supporting components of the driving screw and the driven screw can be fully lubricated and cooled, thus extending the service life of the parts, and can also ensure that the material will not accumulate in the sealing chamber, thus preventing the failure of the seal.

[0031] There are sealed chambers and axial positioning chambers in the pump. The material circulates in the pump, creating two medium pressure zones. The force generated on the screw by the pressure difference between the outlet chamber and the sealed chamber is directed to the right, while the force generated on the screw by the pressure difference between the inlet chamber and the axial positioning chamber is directed to the right, which can offset part of the axial force generated on the screw by the inlet and outlet pressure differences. The positioning bearing bears less axial force, which can greatly extend the service life of the bearing.

[0032] The magnetically driven, leak-free, integral twin-screw pump provided by the present invention can be applied to rotating equipment used under special working conditions in industries such as petrochemicals and new materials. It is magnetically driven by a magnetic transmission and has a leak-free integral seal. It is inherently safe and has excellent adaptability under complex working conditions such as "high temperature, high pressure, high viscosity, flammable and explosive, toxic and harmful media, and multi-phase mixed transmission." BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] FIG1 is a schematic structural diagram of a magnetically driven, leak-free, integral twin-screw pump provided in a specific embodiment of the present invention;

[0035] FIG2 is a cross-sectional view of FIG1 ;

[0036] Fig. 3 is a left side view of Fig. 2;

[0037] FIG4 is a flow diagram of a magnetically driven, leak-free, integral twin-screw pump;

[0038] FIG. 5 is a schematic structural diagram of a magnetic actuator.

[0039] Reference numerals:

[0040] Pump body 1, bushing 2, driving screw 3, driven screw 4, rear end cover 5, front end cover 6, connecting plate 7, sliding sleeve 8, sleeve pressure ring 9, concave wheel 10, convex wheel 11, protective cover 12, bearing seat 13, transmission shaft 14, isolation sleeve 15, inner magnetic cylinder assembly 16, outer magnetic cylinder assembly 17, locating bearing 18, transmission bearing 19, temperature sensor 20. DETAILED DESCRIPTION

[0041] The core of the present invention is to provide a magnetically driven, leak-free, integral twin-screw pump. The twin-screw pump of this structural type is inherently safe and has good adaptability under complex working conditions.

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Please refer to Figures 1 to 5, Figure 1 is a structural schematic diagram of a magnetically driven, leak-free, integral twin-screw pump provided by a specific embodiment of the present invention; Figure 2 is a sectional view of Figure 1; Figure 3 is a left view of Figure 2; Figure 4 is a flow diagram of the magnetically driven, leak-free, integral twin-screw pump; Figure 5 is a structural schematic diagram of the magnetic actuator.

[0044] In a specific embodiment, the magnetically driven, leak-free, integral twin-screw pump provided by the present invention comprises a pump body 1, a sleeve 2 installed on the pump body 1, a driving screw 3 and a driven screw 4 meshing with each other and arranged in parallel in the sleeve 2, and a magnetic transmission connected to the second end of the driving screw 3, the driving screw 3 is axially positioned by a positioning bearing 18, the magnetic transmission forms a sealed chamber C at the second end of the driving screw 3, the first ends of the driving screw 3 and the driven screw 4 form an axial positioning chamber D in the pump body 1, the sleeve 2 is provided with an inlet chamber A on the inlet flange side of the pump body 1, the sleeve 2 is provided with an outlet chamber B on the outlet flange side of the pump body 1, there is a pressure difference between the inlet chamber A and the outlet chamber B, and the magnetic transmission is connected to the prime mover.

[0045] In the above structure, the magnetically driven leak-free integral twin-screw pump includes a pump body 1, a bushing 2, a driving screw 3, a driven screw 4 and a magnetic transmission device. The bushing 2 is arranged in the pump body 1, and the driving screw 3 and the driven screw 4 are radially supported in the bushing 2. The driving screw 3 and the driven screw 4 are parallel and meshed. The driving screw 3 and the driven screw 4 cannot move axially, and the second end of the driving screw 3 extends out of the pump body 1. The magnetic transmission device is connected to the second end of the driving screw 3. The magnetic transmission device is connected to the prime mover. The magnetic transmission device is driven by magnetic force, and the driving screw 3 rotates. Through the meshing of the screws, the driven screw 4 rotates synchronously.

[0046] The pump is divided into four chambers, including an inlet chamber A, an outlet chamber B, a sealing chamber C, and an axial positioning chamber D. See Figure 4. The magnetic transmission forms a sealing chamber C at the second end of the driving screw 3, and the first ends of the driving screw 3 and the driven screw 4 form an axial positioning chamber D in the pump body 1. The bushing 2 is provided with an inlet chamber A on the inlet flange side of the pump body 1, and the bushing 2 is provided with an outlet chamber B on the outlet flange side of the pump body 1. The material enters the inlet chamber A through the flange, and is gradually pressurized under the meshing conveyance of the driving screw 3 and the driven screw 4, and enters the outlet chamber B, and is finally conveyed to the outside of the pump through the flange. There is a pressure difference between the inlet chamber A and the outlet chamber B. Part of the material enters the sealing chamber C through the gap between the bushing 2 on the second side and the driving screw 3 and the driven screw 4, passes through the gap of the magnetic transmission, and finally returns to the inlet chamber A through the connecting hole in the driving screw 3. There is a pressure difference between the inlet chamber A and the outlet chamber B. Part of the material enters the axial positioning chamber D through the connecting hole in the bushing 2, and returns to the inlet chamber A through the gap between the bushing 2 on the left and the driving screw 3 and the driven screw 4.

[0047] The material circulates in the pump, which can ensure that the positioning components and supporting components of the driving screw 3 and the driven screw 4 can be fully lubricated and cooled, thereby extending the service life of the components, and can also ensure that the material will not accumulate in the sealing chamber C, thereby preventing the failure of the seal.

[0048] Because under normal circumstances, a single-suction twin-screw pump will cause high-pressure areas and low-pressure areas to appear in the pump, the inlet chamber A is a low-pressure area, and the outlet chamber B is a high-pressure area, see Figure 4. The direction of the force generated on the screw by the pressure difference between the inlet chamber A and the outlet chamber B is to the left. When the inlet and outlet pressure difference is relatively large, the positioning bearing 18 needs to withstand a considerable axial force, which will seriously affect the life of the bearing. Therefore, the present application is provided with a sealing chamber C and an axial positioning chamber D in the pump, and the material circulates in the pump to generate two medium-pressure areas in the pump. The direction of the force generated on the screw by the pressure difference between the outlet chamber B and the sealing chamber C is to the right, and the direction of the force generated on the screw by the pressure difference between the inlet chamber A and the axial positioning chamber D is to the right, which can offset part of the axial force generated on the screw by the inlet and outlet pressure difference. The positioning bearing 18 withstands a smaller axial force, which can greatly extend the service life of the bearing.

[0049] The magnetically driven, leak-free, integral twin-screw pump provided by the present invention can be applied to rotating equipment used under special working conditions in industries such as petrochemicals and new materials. It is magnetically driven by a magnetic transmission and has a leak-free integral seal. It is inherently safe and has excellent adaptability under complex working conditions such as "high temperature, high pressure, high viscosity, flammable and explosive, toxic and harmful media, and multi-phase mixed transmission."

[0050] Based on the above-mentioned specific embodiments, the magnetic transmission includes an inner magnetic cylinder assembly 16 connected to the second end of the driving screw 3, an outer magnetic cylinder assembly 17 connected to the first end of the transmission shaft 14 and cooperating with the inner magnetic cylinder assembly 16, and an isolation sleeve 15 connected to the second end of the pump body 1 through the connecting plate 7. The isolation sleeve 15 wraps around the inner magnetic cylinder assembly 16 and forms a sealed chamber C, and there are gaps between the inner wall and the outer wall of the isolation sleeve 15 and the inner magnetic cylinder assembly 16 and the outer magnetic cylinder assembly 17, respectively.

[0051] In a specific embodiment, the transmission component of the pump is a magnetic transmission device, as shown in FIG5 , the magnetic transmission device includes an inner magnetic cylinder assembly 16, an outer magnetic cylinder assembly 17 and an isolation sleeve 15, the inner magnetic cylinder assembly 16 is connected to the second end of the driving screw 3, the outer magnetic cylinder assembly 17 is connected to the first end of the transmission shaft 14, the outer magnetic cylinder assembly 17 cooperates with the inner magnetic cylinder assembly 16, the prime mover rotates to drive the transmission shaft 14, and the outer magnetic cylinder assembly 17 on the transmission shaft 14 rotates; through magnetic drive, the inner magnetic cylinder assembly 16 on the driving screw 3 rotates synchronously; the driving screw 3 rotates, and through the screw meshing, the driven screw 4 rotates synchronously. The connecting plate 7 is connected to the second end of the pump body 1, and the isolation sleeve 15 is connected to the second end of the pump body 1 through the connecting plate 7. The isolation sleeve 15 encloses the inner magnetic cylinder assembly 16 and forms a sealed chamber C. The inner wall and outer wall of the isolation sleeve 15 are respectively matched with the inner magnetic cylinder assembly 16 and the outer magnetic cylinder assembly 17. The magnetic actuator adopts a push-pull type large magnetic gap magnetic circuit structure design, which is characterized by high magnetic utilization, small eddy current loss, large torque, no slippage, and good reliability. This structure can fully and effectively utilize magnetic energy. Under the same working conditions, the gap between the isolation sleeve and the inner magnetic rotor can be increased to ensure smooth flow of its own medium and take away the eddy current heat generated by cutting the magnetic lines of force, thereby improving the stability of the pump. At the same time, the design of the special magnetic actuator fully considers the needs of the design temperature and starting torque, and can be directly started with the valve closed. If necessary, it can also be started with the valve open.

[0052] On the basis of the above-mentioned specific embodiments, the inner bottom surface of the isolation sleeve 15 is a convex surface protruding toward the inward magnetic cylinder assembly 16 .

[0053] In a specific embodiment, the inner bottom surface of the isolation sleeve 15 is a convex surface, and the convex surface protrudes outward on one side of the inner magnetic cylinder assembly 16. The inner bottom surface of the isolation sleeve 15 and the inner magnetic cylinder assembly 16 are gap-matched. The convex surface can increase the gap between the outer periphery of the inner bottom surface of the isolation sleeve 15 and the inner magnetic cylinder assembly 16. The increase in the gap can ensure smooth flow of the medium itself, take away more eddy current heat generated by cutting the magnetic lines of force, and improve the stability of the pump.

[0054] Based on the above-mentioned specific embodiments, the inner bottom surface of the isolation sleeve 15 gradually bulges from the outer circumference to the center.

[0055] In a specific embodiment, the end face of the inner magnetic cylinder assembly 16 has a groove hole, and the central part of the protrusion exceeds the end face of the inner magnetic cylinder assembly 16 and enters the groove hole, and a peripheral gap is formed between the outer peripheral part of the protrusion and the groove hole, which not only ensures that the inner bottom surface of the isolation sleeve 15 and the inner magnetic cylinder assembly 16 are clearance-matched, and the lubricating oil can flow through the peripheral gap; it also allows the lubricating oil to be closer to the inner magnetic cylinder assembly 16 and flow into the inner magnetic cylinder assembly 16, taking away more eddy current heat generated by cutting the magnetic lines of force, so that the inner magnetic cylinder assembly 16 is fully lubricated and cooled, thereby extending the service life of the inner magnetic cylinder assembly 16.

[0056] Based on the above-mentioned specific embodiments, the inner bottom surface and the inner wall of the isolation sleeve 15 are connected by a rounded transition, and the rounded corner and the protrusion are smoothly connected by an oblique straight line. There is no dead corner inside the isolation sleeve 15, ensuring that the material will not accumulate in the sealed chamber C, preventing the failure of the seal.

[0057] Based on the above-mentioned specific embodiments, the transmission shaft 14 is arranged in the bearing seat 13, and the two ends of the transmission shaft 14 are supported by transmission bearings 19. The second end of the transmission shaft 14 extends out of the bearing seat 13 and is connected to the prime mover; it also includes a protective cover 12 connecting the bearing seat 13 and the connecting plate 7, and the protective cover 12 is arranged on the outer periphery of the external magnetic cylinder assembly 17.

[0058] In a specific embodiment, the transmission shaft 14 is arranged in the bearing seat 13 and is supported by transmission bearings 19 at both ends. The second end of the transmission shaft 14 extends out of the bearing seat 13 and can be connected to the prime mover; the outer magnetic cylinder assembly 17 is arranged at the first end of the transmission shaft 14, the inner magnetic cylinder assembly 16 is arranged at the second end of the driving screw 3, and the isolation sleeve 15 is arranged on the right side of the connecting plate 7 and wraps the inner magnetic cylinder assembly 16 to form a sealed chamber C.

[0059] The protective cover 12 is arranged on the second side of the connecting plate 7, connecting the bearing seat 13 and the connecting plate 7, and the protective cover 12 surrounds the outer magnetic cylinder assembly 17 to protect the outer magnetic cylinder assembly 17 from external damage.

[0060] Optionally, the protective cover 12 is detachably connected to the bearing seat 13 and the connecting plate 7, such as by bolts, to facilitate maintenance.

[0061] Based on the above-mentioned specific embodiments, a temperature sensor 20 for detecting the temperature inside the pump body 1 is provided on the isolation sleeve 15. The temperature sensor 20 is connected to the start switch of the twin-screw pump. When the current temperature inside the pump body 1 detected by the temperature sensor 20 is greater than or equal to the set temperature, the twin-screw pump stops.

[0062] In actual applications, a temperature sensor 20 is provided on the isolation sleeve in accordance with the heavy-load sealless design regulations. The temperature sensor 20 detects the temperature inside the pump body 1. When the current temperature inside the pump body 1 detected by the temperature sensor 20 is greater than or equal to the set temperature, it indicates that a flow interruption or abnormal fault occurs in the pump. The pump is stopped immediately and the obstacle is removed in time to prevent the pump from burning out or other damages.

[0063] Based on the above-mentioned specific embodiments, the first end of the driving screw 3 has a concave wheel 10, and the first end of the driven screw 4 is provided with a convex wheel 11, the convex wheel 11 is embedded in the concave wheel 10, and the convex wheel 11 and the concave wheel 10 form an axial positioning chamber D in the pump body 1.

[0064] In a specific embodiment, when the driving screw 3 and the driven screw 4 mesh and rotate, the convex wheel 11 and the concave wheel 10 are meshed and connected, and the concave wheel 10 and the convex wheel 11 are used to limit the axial movement of the driven screw 4 and axially position the driven screw 4.

[0065] A concave cam chamber is formed between the convex wheel 11 and the concave wheel 10, namely, the axial positioning chamber D. There is a pressure difference between the inlet chamber A and the outlet chamber B, and part of the material enters the concave cam chamber through the connecting hole in the bushing 2, and returns to the inlet chamber A through the gap between the sliding sleeve 8 on the left and the driving screw 3 and the driven screw 4.

[0066] Based on the above-mentioned specific embodiments, a rear end cover 5 is provided at the first end of the pump body 1, a front end cover 6 is provided at the second end of the pump body 1, a connecting plate 7 is arranged on the second side of the front end cover 6, and sliding sleeves 8 are provided in the openings at both ends of the bushing 2, and the sliding sleeves 8 are used to radially support the driving screw 3 and the driven screw 4.

[0067] In a specific embodiment, the rear end cover 5 is disposed on the first side of the pump body 1, and the first side of the pump body 1 forms a closed chamber. Optionally, the pump body 1 has a groove on the first side, the depth of the groove is less than the thickness of the rear end cover 5, one end of the rear end cover 5 is connected to the groove, the groove radially positions the rear end cover 5, and the groove has a supporting effect on the rear end cover 5 to prevent the rear end cover 5 from radial displacement.

[0068] The front end cover 6 is arranged on the second side of the pump body 1, and the connecting plate 7 is arranged on the second side of the front end cover 6, which can be connected by bolts, so that the isolation sleeve 15 is conveniently connected to the pump body 1. The sliding sleeve 8 is arranged in the openings at both ends of the bushing 2 to radially support the driving screw 3 and the driven screw 4. The sleeve pressure ring 9 is arranged on the left side of the bushing 2 to limit the axial movement of the sliding sleeve 8 on the left side, and the front end cover 6 limits the axial movement of the sliding sleeve 8 on the right side; the positioning bearing 18 is arranged in the front end cover 6 to axially position the driving screw 3.

[0069] Based on the above-mentioned specific embodiments, a sleeve pressing ring 9 is provided on the first side of the bushing 2, and a stepped hole is provided on the side close to the sliding sleeve 8 between the sleeve pressing ring 9 and the front end cover 6. The sliding sleeve 8 on the first side abuts against the stepped hole of the sleeve pressing ring 9, and a locating bearing 18 is arranged in the stepped hole of the front end cover 6. The depth of the stepped hole of the front end cover 6 is greater than the length of the sliding sleeve 8, and the sliding sleeve 8 on the second side abuts against the locating bearing 18.

[0070] In the above embodiment, the sliding sleeve 8 is axially positioned by the stepped hole on the sleeve pressing ring 9 and the front end cover 6. At the same time, the aperture of the stepped hole is tightly matched with the outer diameter of the sliding sleeve 8, such as an interference fit, which limits the rotation of the sliding sleeve 8 in the stepped hole and has a radial positioning effect.

[0071] In a preferred embodiment, the magnetically driven leak-free integral twin-screw pump adopts a new alloy material, which has the advantages of high temperature resistance, wear resistance, corrosion resistance, high strength, etc., and realizes hot self-lubricating maintenance-free continuous operation.

[0072] On the basis of the above-mentioned specific embodiments, the pump body 1 is a double-layer pump body having a heat preservation chamber E. The heat preservation chamber E is used to keep the pump body 1 warm and prevent the material from coking in the pump.

[0073] Optionally, there are supporting ribs connecting the inner shell and the outer shell between the double-layer pump body, and the supporting ribs divide the heat preservation chamber E into a plurality of small chambers, thereby enhancing the connection strength of the double-layer pump body.

[0074] Furthermore, the heat preservation chamber E is evacuated to improve the heat insulation performance, thereby further enhancing the heat preservation performance of the heat preservation chamber E.

[0075] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0076] The magnetically driven, leak-free, integral twin-screw pump provided by the present invention is introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features disclosed herein.

Claims

1. A magnetically driven, leak-free, integral twin-screw pump, characterized in that: The invention comprises a pump body (1), a bushing (2) mounted on the pump body (1), a driving screw (3) and a driven screw (4) meshing with each other and arranged in parallel in the bushing (2), and a magnetic transmission connected to the second end of the driving screw (3), wherein the driving screw (3) is axially positioned by a positioning bearing (18), the magnetic transmission forms a sealed chamber (C) at the second end of the driving screw (3), the first ends of the driving screw (3) and the driven screw (4) form an axial positioning chamber (D) in the pump body (1), the bushing (2) is provided with an inlet chamber (A) on the inlet flange side of the pump body (1), and the bushing (2) is provided with an outlet chamber (B) on the outlet flange side of the pump body (1), a pressure difference exists between the inlet chamber (A) and the outlet chamber (B), and the magnetic transmission is connected to a prime mover.

2. The magnetically driven, leak-free, integral twin-screw pump according to claim 1, characterized in that: The magnetic transmission comprises an inner magnetic cylinder assembly (16) connected to the second end of the driving screw (3), an outer magnetic cylinder assembly (17) connected to the first end of the transmission shaft (14) and cooperating with the inner magnetic cylinder assembly (16), and an isolation sleeve (15) connected to the second end of the pump body (1) via a connecting plate (7), wherein the isolation sleeve (15) encloses the inner magnetic cylinder assembly (16) and forms the sealed chamber (C), and an inner wall and an outer wall of the isolation sleeve (15) respectively have gaps with the inner magnetic cylinder assembly (16) and the outer magnetic cylinder assembly (17).

3. The magnetically driven, leak-free, integral twin-screw pump according to claim 2, characterized in that: The inner bottom surface of the isolation sleeve (15) is a convex curved surface that protrudes toward the inner magnetic cylinder assembly (16).

4. The magnetically driven, leak-free, integral twin-screw pump according to claim 3, characterized in that: The inner bottom surface of the isolation sleeve (15) gradually bulges from the outer circumference to the center, and the inner bottom surface of the isolation sleeve (15) is connected to the inner wall via a rounded corner.

5. The magnetically driven, leak-free, integral twin-screw pump according to claim 2, characterized in that: The transmission shaft (14) is arranged in the bearing seat (13), both ends of the transmission shaft (14) are supported by transmission bearings (19), and the second end of the transmission shaft (14) extends out of the bearing seat (13) and is connected to the prime mover; It also includes a protective cover (12) connecting the bearing seat (13) and the connecting plate (7), wherein the protective cover (12) is arranged on the outer periphery of the outer magnetic cylinder assembly (17).

6. The magnetically driven, leak-free, integral twin-screw pump according to claim 2, characterized in that: The isolation sleeve (15) is provided with a temperature sensor (20) for detecting the temperature inside the pump body (1), and the temperature sensor (20) is connected to a start switch of the twin-screw pump. When the temperature inside the pump body (1) detected by the temperature sensor (20) is greater than or equal to a set temperature, the twin-screw pump stops.

7. The magnetically driven, leak-free, integral twin-screw pump according to claim 5, characterized in that: The first end of the driving screw (3) is provided with a concave wheel (10), and the first end of the driven screw (4) is provided with a convex wheel (11), the convex wheel (11) is embedded in the concave wheel (10), and the convex wheel (11) and the concave wheel (10) form the axial positioning chamber (D) in the pump body (1).

8. The magnetically driven, leak-free, integral twin-screw pump according to claim 7, characterized in that: The first end of the pump body (1) is provided with a rear end cover (5), the second end of the pump body (1) is provided with a front end cover (6), the connecting plate (7) is arranged on the second side of the front end cover (6), and sliding sleeves (8) are provided in openings at both ends of the bushing (2), and the sliding sleeves (8) are used to radially support the driving screw (3) and the driven screw (4).

9. The magnetically driven, leak-free, integral twin-screw pump according to claim 8, characterized in that: A sleeve pressing ring (9) is provided on the first side of the bushing (2); the sleeve pressing ring (9) and the front end cover (6) are provided with a stepped hole on a side close to the sliding sleeve (8); the sliding sleeve (8) on the first side abuts against the stepped hole of the sleeve pressing ring (9); the locating bearing (18) is arranged in the stepped hole of the front end cover (6); the depth of the stepped hole of the front end cover (6) is greater than the length of the sliding sleeve (8); and the sliding sleeve (8) on the second side abuts against the locating bearing (18).

10. The magnetically driven, leak-free, integral twin-screw pump according to any one of claims 1 to 9, characterized in that: The pump body (1) is a double-layer pump body having a heat-insulating chamber (E).

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