Magnet-driven melt gear pump

Abstract

The utility model relates to the technical field of melt gear pumps, and particularly discloses a magnet-driven melt gear pump which comprises a pump body, one end of the pump body is provided with a through hole, a driving shaft is arranged in the pump body, and one end of the driving shaft extends out of the through hole; one end of the magnetic transmission coupler is connected with the pump body, and the magnetic transmission coupler comprises an inner magnetic rotor, a magnetic transmission shaft and a magnetic transmission shaft, the outer magnetic rotor is arranged outside the inner magnetic rotor; the shielding sleeve is located between the inner magnetic rotor and the outer magnetic rotor, and the shielding sleeve is used for separating the inner magnetic rotor from the outer magnetic rotor; and the driving motor is connected to the other end of the magnetic transmission coupling. After the magnet-driven melt gear pump disclosed by the utility model is shut down, compressed gas is introduced into the gas inlet, so that residual materials in the first rotating gap can be discharged through the gas outlet, the first rotating gap is kept in an emptying state, high-temperature materials can be prevented from denaturation due to accumulation and cooling, the difficulty in starting next time is further avoided, and the fault occurrence rate is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of melt gear pumps, in particular to a magnet-driven melt gear pump. Background Art

[0002] As a fluid conveying power part in the production of polylactic acid, the melt gear pump is mainly used for conveying, pressurizing and metering high-temperature and high-viscosity polymer melts. It is mainly composed of a pump housing, a driving gear, a driven gear, a sliding bearing, front and rear end plates, and a packing seal. The driving gear is set on the driving shaft, and the driven gear is set on the driven shaft. When working, the melt is conveyed by the change in working volume caused by the mutual meshing of the driving and driven gears. The working volume is composed of the pump body, the tooth grooves of the gears, and the bearings with the function of the side plates (i.e., the feed area). When the gears rotate in the specified direction, the melt enters the tooth grooves of the two gears in the feed area. As the gears rotate, the melt is brought into the feed area from both sides. The re-engagement of the gears squeezes the melt in the tooth grooves out of the discharge area and presses it to the outlet pipe. As long as the pump shaft rotates, the gears press the melt to the outlet side, so the pump outlet can reach a very high pressure.

[0003] During the production of polylactic acid, the melt gear pump is in a high vacuum feeding state and no outside air is allowed to enter the reaction system. Conventional packing seals, labyrinth seals or spiral dynamic seals are difficult to achieve a complete sealing effect. Double-end mechanical seals with flushing devices can achieve a better sealing effect, but due to the high corrosiveness of the conveyed materials and the high working temperature, the metal components of the mechanical seal need to be made of duplex stainless steel. In this case, the production requirements for mechanical seals are high, the cost is high, and it is not suitable for working conditions with excessively high pressure. At the same time, once the mechanical seal fails or needs to be replaced, the operation is relatively cumbersome, the installation accuracy requirements are high, and the sealing effect and life are affected by the workers' operating level.

[0004] As a substitute for traditional couplings, magnetic transmission couplings are non-contact couplings. They are generally composed of two inner and outer magnets, which are separated by a shielding sleeve in the middle. The inner magnetic rotor is connected to the driven part, and the outer magnetic rotor is connected to the power part. The outer wall of the inner magnetic rotor is in sliding contact with the inner wall of the shielding sleeve. Based on the rotation needs, the inner magnetic rotor will form a rotation gap with the pump body and the shielding sleeve at both ends in the axial direction. In addition to the function of elastic coupling to buffer and absorb vibration, the biggest feature of the magnetic transmission coupling is that it breaks the structural form of the traditional coupling and adopts a new magnetic coupling principle to achieve the transmission of force and torque between the driving shaft and the driven shaft without direct contact, and can transform the dynamic seal into a static seal to achieve zero leakage. Therefore, it is widely used in occasions with special requirements for leakage.

[0005] However, when the magnetic coupling is directly used in the above-mentioned melt gear pump for polylactic acid, material residues will often be generated during shutdown or maintenance due to the material entering the rotation gap between the inner magnetic rotor and the pump body. The residual high-temperature material is easily deformed after cooling, resulting in difficulty in starting the machine next time or causing malfunctions.

[0006] Therefore, how to solve the problem that when the magnetic coupling is directly applied to the above-mentioned melt gear pump for polylactic acid, material residue is generated during shutdown or maintenance due to the material entering the rotating gap between the inner magnetic rotor and the pump body, and the residual high-temperature material is easily deformed after cooling, resulting in difficulty in starting the machine next time or causing malfunctions, has become a technical problem that technical personnel in this field urgently need to solve. Utility Model Content

[0007] In view of this, the utility model proposes a magnet-driven melt gear pump to address the deficiencies in the prior art, aiming to solve the problem that when the magnetic coupling is directly applied to the above-mentioned melt gear pump for polylactic acid, material residue is generated during shutdown or maintenance due to the material entering the rotating gap between the inner magnetic rotor and the pump body, and the residual high-temperature material is easily deformed after cooling, resulting in difficulty in starting the machine next time or causing malfunctions.

[0008] The utility model provides a magnet-driven melt gear pump, comprising:

[0009] A pump body, one end of which is provided with a through hole, a driving shaft is provided inside the pump body, and one end of the driving shaft extends out of the through hole;

[0010] A magnetic transmission coupling, one end of which is connected to the pump body, and the magnetic transmission coupling comprises:

[0011] An inner magnetic rotor is mounted on the driving shaft;

[0012] An outer magnetic rotor, arranged outside the inner magnetic rotor;

[0013] A shielding sleeve, located between the inner magnetic rotor and the outer magnetic rotor, the shielding sleeve is used to separate the inner magnetic rotor from the outer magnetic rotor;

[0014] The driving motor is connected to the other end of the magnetic transmission coupling.

[0015] Further, the shielding sleeve includes an inner shielding sleeve and an outer shielding sleeve which are sequentially arranged from the inside to the outside, and the magnet-driven melt gear pump also includes:

[0016] a first rotation gap, wherein the first rotation gap is formed between one end of the inner rotor and the pump body;

[0017] A second rotation gap is provided between the other end of the inner magnetic rotor and the inner shielding sleeve.

[0018] Furthermore, the magnet-driven melt gear pump further comprises:

[0019] A reflux channel is provided between one end of the driving shaft and the second rotating gap, and the reflux channel is used to connect the first rotating gap and the second rotating gap.

[0020] Furthermore, the magnet-driven melt gear pump further comprises:

[0021] A mounting plate, wherein the mounting plate is sleeved on one end of the driving shaft extending out of the pump body, and the shielding sleeve is disposed on the mounting plate; the first rotation gap is located between the mounting plate and one end of the inner magnetic rotor;

[0022] An air inlet and an air outlet are located on the mounting plate, the air inlet and the air outlet are both connected to the first rotating gap, and the air inlet and the air outlet extend along the radial direction of the driving shaft and are located on the same straight line;

[0023] Valves are located on the air inlet and the air outlet.

[0024] Furthermore, the shielding sleeve is also provided with a heat medium inlet and a heat medium outlet which are connected to the cavity, and the heat medium inlet and the heat medium outlet are both located at one end of the shielding sleeve close to the mounting plate, and the heat medium inlet and the heat medium outlet extend along the radial direction of the driving shaft and are located on the same straight line.

[0025] Furthermore, the inner magnetic rotor is a step-shaped structure, and a magnet block is provided at the step of the inner magnetic rotor;

[0026] The heating channel is located inside the pump body.

[0027] Further, the magnet driven melt gear pump also includes:

[0028] A fixed seat, which is a square frame structure;

[0029] A fixing plate, located in the middle part of the top of the fixing seat;

[0030] A connecting plate, the connecting plate is located above the fixing plate and the connecting plate is bolted to the fixing plate;

[0031] There are two support plates, and the two support plates are arranged side by side above the connecting plate in the vertical direction.

[0032] Furthermore, the pump body and the drive motor are respectively fixed on the sides of the two support plates away from each other, the magnetic transmission coupling is located between the two support plates, and the pump body, the drive motor and the magnetic transmission coupling are coaxially arranged.

[0033] Compared with the prior art, the utility model has the beneficial effect that the magnet-driven melt gear pump provided by the utility model can smoothly extend the driving shaft out of the pump body and be connected to the magnetic transmission coupling by setting a through hole at one end of the pump body. By setting a shielding sleeve between the inner magnetic rotor and the outer magnetic rotor, wear, noise and failure rate are effectively reduced, and the reliability and service life of the pump body are improved; after shutdown, the compressed gas is introduced into the air inlet to discharge the residual material in the first rotating gap through the air outlet, so that the first rotating gap remains empty, which can avoid the high-temperature material from accumulating and cooling and degenerating, thereby avoiding the difficulty of starting the machine next time and reducing the failure rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a cross-sectional view of the magnetic transmission coupling of the magnet-driven melt gear pump of the utility model;

[0035] Figure 2 This is a schematic diagram of the structure of the shielding sleeve of the magnet-driven melt gear pump of the utility model;

[0036] Figure 3 This utility model magnet driven melt gear pump Figure 2 Schematic diagram of the structure in direction A.

[0037] In the figure: 110, driving shaft; 200, magnetic transmission coupling; 210, inner magnetic rotor; 211, magnet block; 220, outer magnetic rotor; 230, shielding sleeve; 231, heat medium inlet; 232, heat medium outlet; 240, first rotating gap; 241, air inlet; 242, air outlet; 243, valve; 250, second rotating gap; 260, return channel; 270, mounting plate. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0040] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0041] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] See also Figure 1-3 As shown, this embodiment provides a magnet-driven melt gear pump, comprising:

[0043] The pump body has a through hole at one end thereof, a driving shaft 110 is arranged inside the pump body, and one end of the driving shaft 110 extends out of the through hole.

[0044] A magnetic transmission coupling 200, one end of which is connected to the pump body, and the magnetic transmission coupling 200 comprises:

[0045] The inner magnetic rotor 210 is mounted on the driving shaft 110 .

[0046] The outer magnetic rotor 220 is disposed outside the inner magnetic rotor 210 .

[0047] The shielding sleeve 230 is located between the inner magnetic rotor 210 and the outer magnetic rotor 220 . The shielding sleeve 230 is used to separate the inner magnetic rotor 210 from the outer magnetic rotor 220 .

[0048] The driving motor is connected to the other end of the magnetic transmission coupling 200 .

[0049] It can be seen that by providing a through hole at one end of the pump body, the driving shaft 110 inside the pump body can smoothly extend out of the through hole and connect to the magnetic transmission coupling 200. This makes the energy transmission between the pump body and the magnetic transmission coupling 200 more efficient, while reducing the wear and failure rate of the traditional mechanical transmission method.

[0050] The magnetic transmission coupling 200 separates the inner magnetic rotor 210 from the outer magnetic rotor 220, and prevents direct contact between the two through the shielding sleeve 230, effectively solving the problems of wear, noise and high failure rate existing in the traditional magnetic transmission coupling 200; the shielding sleeve 230 can also prevent impurities in the pump body from entering the magnetic transmission coupling 200, thereby extending the service life of the magnetic transmission coupling 200.

[0051] The driving motor is connected to the other end of the magnetic transmission coupling 200, providing power for the entire system.

[0052] It is understandable that the magnet-driven melt gear pump provided by the utility model, by providing a through hole at one end of the pump body, allows the driving shaft 110 to smoothly extend out of the pump body and be connected to the magnetic transmission coupling 200. By providing a shielding sleeve 230 between the inner magnetic rotor 210 and the outer magnetic rotor 220, wear, noise and failure rate are effectively reduced, and the reliability and service life of the pump body are improved.

[0053] Specifically, the shielding sleeve 230 includes an inner shielding sleeve 230 and an outer shielding sleeve 230 which are sequentially arranged from the inside to the outside, and the magnet-driven melt gear pump further includes:

[0054] A first rotating gap 240 is formed between one end of the inner rotor and the pump body.

[0055] A second rotation gap 250 is defined between the other end of the inner magnetic rotor 210 and the inner shielding sleeve 230 .

[0056] Specifically, the magnet driven melt gear pump also includes:

[0057] A reflux channel 260 is provided between one end of the driving shaft 110 and the second rotating gap 250 . The reflux channel 260 is used to connect the first rotating gap 240 and the second rotating gap 250 .

[0058] Specifically, the magnet driven melt gear pump also includes:

[0059] The mounting plate 270 is sleeved on one end of the driving shaft 110 extending out of the pump body, and a shielding sleeve 230 is disposed on the mounting plate 270 ; the first rotation gap 240 is located between the mounting plate 270 and one end of the inner magnetic rotor 210 .

[0060] The air inlet 241 and the air outlet 242 are located on the mounting plate 270 . Both the air inlet 241 and the air outlet 242 are connected to the first rotating gap 240 . The air inlet 241 and the air outlet 242 extend along the radial direction of the driving shaft 110 and are located on the same straight line.

[0061] The valve 243 is located on the air inlet 241 and the air outlet 242 .

[0062] It can be seen that by setting the first rotating gap 240 and the second rotating gap 250, the friction loss and heat generation inside the magnet-driven melt gear pump can be effectively reduced, thereby improving the working efficiency of the pump; the reflux channel 260 can enable the pump to realize self-circulation of the liquid during operation, thereby avoiding the deposition and blockage of the melt inside the pump, and further improving the operating stability of the magnet-driven melt gear pump; the mounting plate 270 not only ensures the stability of the pump body, but also realizes the good cooperation between the shielding sleeve 230 and the inner magnetic rotor 210, so that the magnet-driven melt gear pump can effectively shield the influence of the magnetic field on other internal components of the magnet-driven melt gear pump during operation, thereby reducing the failure rate of the pump; the setting of the air inlet 241 and the air outlet 242 enables the magnet-driven melt gear pump to realize smooth flow of gas during operation, thereby avoiding the generation of bubbles and ensuring the suction performance of the pump.

[0063] It can be understood that after shutdown, the compressed gas introduced into the air inlet 241 can discharge the residual material in the first rotating gap 240 through the air outlet 242, so that the first rotating gap 240 remains empty, which can prevent the high-temperature material from accumulating and cooling down and degenerating, thereby avoiding difficulties in starting the machine next time and reducing the occurrence of failures.

[0064] Specifically, the shielding sleeve 230 is also provided with a heat medium inlet 231 and a heat medium outlet 232 which are connected to the cavity. The heat medium inlet 231 and the heat medium outlet 232 are both located at one end of the shielding sleeve 230 close to the mounting plate 270. The heat medium inlet 231 and the heat medium outlet 232 extend along the radial direction of the driving shaft 110 and are located on the same straight line.

[0065] Specifically, the inner magnetic rotor 210 is a step-shaped structure, and a magnet block 211 is provided at the step of the inner magnetic rotor 210 .

[0066] The heating channel is located inside the pump body.

[0067] It can be seen that the heat medium inlet 231 and the heat medium outlet 232 can conveniently adjust the flow direction and speed of the heat medium, thereby realizing precise control of the temperature inside the pump body; in order to detect the rotational speed of the inner magnetic rotor 210, avoid the outer magnetic rotor 220 from idling, or the rotational speed difference between the inner and outer magnetic rotors 220, and avoid the risk of magnetic failure that may result, the inner magnetic rotor 210 is provided with a magnet block 211 for a Hall sensor to sense the signal and thereby detect the rotational speed of the inner magnetic rotor 210, and the Hall sensor is used to sense the signal of the magnet block and thereby calculate the rotational speed of the inner magnetic rotor 210 using the signal generation interval.

[0068] Specifically, the magnet driven melt gear pump also includes:

[0069] The fixing seat is a square frame structure.

[0070] A fixing plate, located in the middle part of the top of the fixing seat;

[0071] The connecting plate is located above the fixing plate and is connected to the fixing plate by bolts.

[0072] There are two support plates, which are arranged side by side above the connecting plate in a vertical direction.

[0073] Specifically, the pump body and the drive motor are respectively fixed on the sides of the two support plates away from each other, the magnetic transmission coupling 200 is located between the two support plates, and the pump body, the drive motor and the magnetic transmission coupling 200 are coaxially arranged.

[0074] It can be seen that the fixed seat, fixed plate, connecting plate and support plate can well fix the structure of the entire magnet-driven melt gear pump, so that it remains stable during operation; in addition, the pump body, drive motor and magnetic transmission coupling 200 can be coaxially arranged, thereby improving the working efficiency and reliability of the pump.

[0075] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A magnet driven melt gear pump, characterized in that: include: A pump body, one end of which is provided with a through hole, a driving shaft is provided inside the pump body, and one end of the driving shaft extends out of the through hole; A magnetic transmission coupling, one end of which is connected to the pump body, and the magnetic transmission coupling comprises: An inner magnetic rotor is mounted on the driving shaft; An outer magnetic rotor, arranged outside the inner magnetic rotor; A shielding sleeve, located between the inner magnetic rotor and the outer magnetic rotor, the shielding sleeve is used to separate the inner magnetic rotor from the outer magnetic rotor; The driving motor is connected to the other end of the magnetic transmission coupling.

2. The magnet driven melt gear pump according to claim 1, characterized in that: The shielding sleeve comprises an inner shielding sleeve and an outer shielding sleeve which are sequentially arranged from the inside to the outside, and the magnet-driven melt gear pump further comprises: a first rotating gap, wherein the first rotating gap is formed between one end of the inner magnetic rotor and the pump body; A second rotation gap is provided between the other end of the inner magnetic rotor and the inner shielding sleeve.

3. The magnet driven melt gear pump according to claim 2, characterized in that: The magnet driven melt gear pump also includes: A reflux channel is provided between one end of the driving shaft and the second rotating gap, and the reflux channel is used to connect the first rotating gap and the second rotating gap.

4. The magnet driven melt gear pump according to claim 3, characterized in that: The magnet driven melt gear pump also includes: A mounting plate, wherein the mounting plate is sleeved on one end of the driving shaft extending out of the pump body, and the shielding sleeve is disposed on the mounting plate; the first rotation gap is located between the mounting plate and one end of the inner magnetic rotor; An air inlet and an air outlet are located on the mounting plate, the air inlet and the air outlet are both connected to the first rotating gap, and the air inlet and the air outlet extend along the radial direction of the driving shaft and are located on the same straight line; Valves are located on the air inlet and the air outlet.

5. The magnet driven melt gear pump according to claim 4, characterized in that: The shielding sleeve is also provided with a heat medium inlet and a heat medium outlet which are connected with the cavity. The heat medium inlet and the heat medium outlet are both located at one end of the shielding sleeve close to the mounting plate. The heat medium inlet and the heat medium outlet extend along the radial direction of the driving shaft and are located on the same straight line.

6. The magnet driven melt gear pump according to claim 1, characterized in that: The inner magnetic rotor is a step-shaped structure, and a magnet block is provided at the step of the inner magnetic rotor; The heating channel is located inside the pump body.

7. The magnet driven melt gear pump according to claim 1, characterized in that: The magnet driven melt gear pump also includes: A fixed seat, which is a square frame structure; A fixing plate, located in the middle part of the top of the fixing seat; A connecting plate, the connecting plate is located above the fixing plate and the connecting plate is bolted to the fixing plate; There are two support plates, and the two support plates are arranged side by side above the connecting plate in the vertical direction.

8. The magnet driven melt gear pump according to claim 7, characterized in that: The pump body and the drive motor are respectively fixed on the sides of the two support plates away from each other, the magnetic transmission coupling is located between the two support plates, and the pump body, the drive motor and the magnetic transmission coupling are coaxially arranged.

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