High-precision screw pump for conveying high-viscosity materials

Abstract

This invention provides a high-precision screw pump for conveying high-viscosity materials, belonging to the field of screw pump transmission technology. It includes a motor, a screw shaft, a connecting sleeve, a bushing, and a driver. The screw shaft is drivenly connected to the motor. The connecting sleeve is sleeved on the outside of the screw shaft, located on one side of the motor and used for fixing to a support surface. The bushing is rotatably disposed between the connecting sleeve and the screw shaft, and cooperates with the screw shaft to convey materials. The driver is fixed to the connecting sleeve and drivenly connected to the bushing, used to drive the bushing to rotate in the opposite direction relative to the screw shaft. When the relative speed between the screw shaft and the bushing remains constant, the driver reduces the output power of the motor. The high-precision screw pump for conveying high-viscosity materials provided by this invention reduces the operating resistance of the motor, thereby allowing for a suitable reduction in motor size and extending the motor's service life.

Description

Technical Field

[0001] This invention belongs to the field of screw pump transmission technology, and more specifically, relates to a high-precision screw pump for conveying high-viscosity materials. Background Technology

[0002] A screw pump is a positive displacement rotary pump that relies on the change and movement of the volume of the meshing space formed by the pump body and the screw to transport or pressurize liquids. The working principle of a screw pump is to use the rotation of the screw to draw in and discharge liquids. Due to the meshing of the screws and the tight fit between the screw and the inner wall of the bushing, one or more sealed spaces are created between the pump's suction inlet and discharge outlet. As the screw rotates and meshes, these sealed spaces are continuously formed at the pump's suction end, sealing the liquid in the suction chamber within them. The liquid is then continuously pushed from the suction chamber along the screw's axial direction to the discharge end, continuously discharging the liquid enclosed in each space, much like a nut continuously moving forward as its threads rotate.

[0003] In existing screw pumps, the screw shaft is driven by a motor, which needs to provide sufficient force to ensure stable rotation. However, since screw pumps typically transport materials with a certain viscosity, the material creates significant resistance to the screw shaft's rotation during transport, causing the motor to operate at high power and affecting its lifespan. Currently, only larger-sized motors can be selected, which makes transportation and installation inconvenient. Summary of the Invention

[0004] The purpose of this invention is to provide a high-precision screw pump for conveying high-viscosity materials, aiming to solve the problem that the large load on a single motor in practical applications leads to a short service life.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a high-precision screw pump for conveying high-viscosity materials, comprising:

[0006] Electric motor;

[0007] The screw shaft is connected to the motor drive.

[0008] A connecting sleeve is fitted onto the outside of the screw shaft, and the connecting sleeve is fitted onto one side of the motor and used to fix it to the support surface;

[0009] A bushing is rotatably disposed between the connecting sleeve and the screw shaft, and the bushing cooperates with the screw shaft to transport materials;

[0010] A driver, fixed to the connecting sleeve and connected to the bushing in a transmission manner, is used to drive the bushing to rotate in the opposite direction relative to the screw shaft;

[0011] With the relative speed between the screw shaft and the bushing remaining constant, the driver is used to reduce the output power of the motor.

[0012] In one possible implementation, the drive includes a worm gear and a worm, the worm gear being fitted onto the outer wall of the bushing, a motor being mounted on the connecting sleeve, and the worm being mounted on the output shaft of the motor and engaging with the worm gear in a transmission manner.

[0013] In one possible implementation, a transmission sleeve is fixed to the end of the bushing near the motor, and the worm gear is mounted on the transmission sleeve.

[0014] In one possible implementation, the end of the connecting sleeve near the motor is provided with a limiting sleeve, and the limiting sleeve is sealed against the transmission sleeve.

[0015] In one possible implementation, a limiting body is provided between the bushing and the connecting sleeve, and the bushing and the connecting sleeve form a flow channel by means of the limiting body.

[0016] In one possible implementation, the limiting body includes a plurality of rolling elements.

[0017] In one possible implementation, the limiting body is spirally wound around the outer wall of the bushing, and the two ends of the connecting sleeve are respectively equipped with an inlet pipe and an outlet pipe. The limiting body rotates relative to the bushing to transport the liquid discharged by the inlet pipe to the outlet pipe.

[0018] In one possible implementation, the limiting body is integrally formed with the bushing.

[0019] In one possible implementation, cooling grooves are spirally provided along the outer wall of the bushing.

[0020] In one possible implementation, a flow meter is installed at the inlet end of the screw shaft to detect the flow rate of the material; and the flow meter is communicatively connected to a controller, which is electrically connected to the motor and the electric motor respectively to adjust the speed of the motor and the electric motor.

[0021] The advantages of the high-precision screw pump for conveying high-viscosity materials provided by this invention are as follows: Compared with the prior art, in this invention, the screw shaft is driven and connected to the motor, and a connecting sleeve is provided on one side of the motor. The connecting sleeve is fixed to the support surface and is sleeved on the outer side of the screw. A bushing is rotatably provided between the connecting sleeve and the screw shaft, and the driver fixed on the connecting sleeve is driven and connected to the bushing.

[0022] In practical applications, a motor drives the screw shaft, and the rotation of the screw shaft relative to the bushing transfers material from one side of the screw shaft to the other. To reduce the resistance encountered by the motor during operation, a driver moves the bushing in the opposite direction relative to the screw shaft. Therefore, at the same relative speed, the speed of the screw shaft will be reduced, which means the running resistance of the motor is reduced. This allows for a suitable reduction in the size of the motor and extends its service life. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a high-precision screw pump for conveying high-viscosity materials provided in Embodiment 1 of the present invention;

[0025] Figure 2 This is a schematic diagram of the connection between the limiting body and the bushing provided in Embodiment 2 of the present invention;

[0026] Figure 3 This is a schematic diagram of the connection between the rolling element and the bushing provided in Embodiment 3 of the present invention.

[0027] In the diagram: 1. Motor; 2. Screw shaft; 3. Connecting sleeve; 4. Bushing; 5. Limiting body; 6. Inlet pipe; 7. Outlet pipe; 8. Worm; 9. Worm wheel; 10. Flow meter; 11. Rolling element; 12. Cooling tank; 13. Transmission sleeve; 14. Limiting sleeve. Detailed Implementation

[0028] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0029] Please refer to the following: Figures 1 to 3The high-precision screw pump for conveying high-viscosity materials provided by the present invention will now be described. The high-precision screw pump for conveying high-viscosity materials includes: a motor 1, a screw shaft 2, a connecting sleeve 3, a bushing 4, and a driver. The screw shaft 2 is drivenly connected to the motor 1. The connecting sleeve 3 is sleeved on the outside of the screw shaft 2, located on one side of the motor 1, and used to fix it to a support surface. The bushing 4 is rotatably disposed between the connecting sleeve 3 and the screw shaft 2, and the bushing 4 cooperates with the screw shaft 2 to transport materials. The driver is fixed to the connecting sleeve 3 and drivenly connected to the bushing 4, and is used to drive the bushing 4 to rotate in the opposite direction relative to the screw shaft 2. When the relative speed between the screw shaft 2 and the bushing 4 remains constant, the driver is used to reduce the output power of the motor 1.

[0030] The advantages of the high-precision screw pump for conveying high-viscosity materials provided by this invention are as follows: Compared with the prior art, in this invention, the screw shaft 2 is connected to the motor 1 via a transmission connection, and a connecting sleeve 3 is provided on one side of the motor 1. The connecting sleeve 3 is fixed to the support surface and is sleeved on the outer side of the screw. A bushing 4 is rotatably arranged between the connecting sleeve 3 and the screw shaft 2, and the driver fixed on the connecting sleeve 3 is connected to the bushing 4 via a transmission connection.

[0031] In practical applications, motor 1 drives the screw shaft 2, and the rotation of the screw shaft 2 relative to the bushing 4 transfers material from one side of the screw shaft 2 to the other. To reduce the resistance encountered by the motor 1 during operation, the bushing 4 is driven by a driver to move in the opposite direction relative to the screw shaft 2. Therefore, at the same relative speed, the speed of the screw shaft 2 will be reduced, which means the running resistance of the motor 1 will be reduced. This allows for a suitable reduction in the size of the motor 1 and extends its service life.

[0032] A screw pump is a positive displacement rotary pump that relies on the volume change of the sealed cavity formed by the screw and bushing to draw in and discharge liquids. Screw pumps are characterized by stable flow rate, low pressure pulsation, self-priming capability, low noise, high efficiency, long service life, and reliable operation. Their outstanding advantages include not forming eddies when conveying media, insensitivity to the viscosity of the media, and the ability to convey high-viscosity media.

[0033] A single screw pump is a rotary positive displacement pump that primarily transports media by creating volume changes at the suction and discharge ends through the meshing of bolts and bushings 4. It is an internally meshing, sealed screw pump, with its main components consisting of a double-ended helical cavity bushing 4 and a single-ended helical screw meshing with it within the stator cavity. When the input shaft drives the rotor to planetary rotate around the stator using a universal joint, the stator and rotor continuously mesh to form a sealed cavity. These sealed cavities have a fixed volume. The single screw pump only needs to move axially at a uniform speed to transport the media from the suction end through the stator-rotor pair to the discharge end. The media drawn into the sealed cavity flows through the stator without being agitated or damaged.

[0034] Traditional screw pumps consist of a stator and a rotor. The stator is stationary, while the rotor needs to be driven by a motor 1 to transfer materials. The resistance experienced by the motor 1 comes from two sources: firstly, the resistance caused by the mutual movement between the rotor and stator, and even the vacuum created in the meshing space; and secondly, the resistance exerted on the rotor by the viscosity of the material itself during transport. Current methods rely solely on the motor 1 to counteract these resistances, which places high demands on the motor's dimensions and operating conditions.

[0035] In some embodiments of the high-precision screw pump for conveying high-viscosity materials provided in this application, please refer to... Figure 1 The drive includes a worm gear 9 and a worm 8. The worm gear 9 is fitted on the outer wall of the bushing 4. The motor is mounted on the connecting sleeve 3. The worm 8 is mounted on the output shaft of the motor and is driven by the worm gear 9.

[0036] It should be noted that this application is aimed at the conveying of materials with high viscosity. In order to convey such materials, it is usually necessary to equip the motor 1 with a larger size so as to ensure that the motor 1 can provide sufficient driving force.

[0037] In practical applications, if the bushing 4 is fixed, the motor 1, which drives the screw shaft 2, needs to bear the resistance encountered when driving the screw shaft 2 to rotate. If the screw shaft 2 is stationary and the bushing 4 completes the material conveying, then the driver, which drives the bushing 4, bears the resistance. When both motors 1 move simultaneously, the resistance can be appropriately distributed.

[0038] In this application, to drive the bushing 4 to rotate, one embodiment involves installing a gear on the outside of the bushing 4 and a driver on the connecting sleeve 3, which then drives the bushing 4 to move. If the driver is a common motor 1, then during the material conveying process, the material and screw shaft 2 exert a certain force on the bushing 4, and this force ultimately needs to be braked by the driver, which places certain demands on the driver.

[0039] For materials with very high viscosity, the resistance encountered during material transport is extremely high. Even when the bushing 4 is stationary, the force exerted on the bushing 4 by the material and the screw shaft 2 is still very large. If the bushing 4 is braked by the driver, all the resistance will act on the driver, and ordinary motor 1 does not have good braking performance. Therefore, the bushing 4 is driven by the worm gear 9 and worm 8. The transmission of the worm gear 9 and worm 8 ensures the smooth movement of the bushing 4, and at the same time, the worm gear 9 and worm 8 can also resist the force exerted on the bushing 4 through their self-locking performance.

[0040] In some embodiments of the high-precision screw pump for conveying high-viscosity materials provided in this application, please refer to... Figure 1 The bushing 4 is fixed with a transmission sleeve 13 near the end of the motor 1, and the worm gear 9 is mounted on the transmission sleeve 13.

[0041] The transmission sleeve 13 can be regarded as part of the bushing 4. The transmission sleeve 13 has a regular cylindrical structure. The worm gear 9 can be directly welded and fixed on the transmission sleeve 13, and the motor 1 is connected to the transmission sleeve 13 for transmission.

[0042] In some embodiments of the high-precision screw pump for conveying high-viscosity materials provided in this application, please refer to... Figure 1 A limiting sleeve 14 is provided at the end of the connecting sleeve 3 near the motor 1, and the limiting sleeve 14 seals against the transmission sleeve 13. The limiting sleeve 14 extends from the end of the connecting sleeve 3 to the transmission sleeve 13, and a sealing gasket is provided at the end of the limiting sleeve 14 away from the connecting sleeve 3. The sealing gasket is used to seal the gap between the limiting sleeve 14 and the bushing 4. Due to the presence of the sealing gasket, leakage of liquid between the connecting sleeve 3 and the bushing 4 is prevented.

[0043] In some embodiments of the high-precision screw pump for conveying high-viscosity materials provided in this application, please refer to... Figure 1 and Figure 2 A limiting body 5 is provided between the bushing 4 and the connecting sleeve 3, and the bushing 4 and the connecting sleeve 3 form a flow channel with the help of the limiting body 5.

[0044] The screw shaft 2 rotates at different speeds relative to the bushing 4. Since the bushing 4 needs to rotate in this application, a component that can stably support the rotation of the bushing 4 is required. A connecting sleeve 3 is provided on the outside of the bushing 4, and the position of the connecting sleeve 3 is relatively stable. In order to stably support the bushing 4, a limiting body 5 needs to be provided between the bushing 4 and the connecting sleeve 3. The limiting body 5 is fixed on the bushing 4, and during the rotation of the bushing 4, the limiting body 5 moves with the bushing 4.

[0045] The presence of the limiting body 5 creates a gap between the bushing 4 and the connecting sleeve 3, forming a flow channel between them. Since both the screw shaft 2 and the bushing 4 experience high temperatures when conveying high-viscosity liquids, coolant can be injected into the flow channel to improve cooling. The coolant directly contacts the bushing 4, reducing its temperature and ultimately preventing the screw shaft 2 from overheating.

[0046] In some embodiments of the high-precision screw pump for conveying high-viscosity materials provided in this application, please refer to... Figure 3 The limiting body 5 includes multiple rolling elements 11.

[0047] In order to reduce the resistance encountered by the bushing 4 when rotating relative to the connecting sleeve 3, multiple rolling elements 11 can be installed circumferentially along the outer wall of the bushing 4. The rolling elements 11 follow the movement of the bushing 4 and rotate against the inner wall of the connecting sleeve 3. Since the rolling elements 11 are always rotating, the resistance encountered by the driver is reduced, so that the bushing 4 can rotate more smoothly.

[0048] The rolling element 11 can reduce the friction between the limiting body 5 and the connecting sleeve 3. However, this method is more often used in situations where only a single liquid needs to be transported and the viscosity is relatively low. That is, only the screw shaft 2 and the bushing 4 need to cooperate to transport the liquid. In this case, the flow channel between the connecting sleeve 3 and the bushing 4 can be filled with coolant, and the purpose of cooling can be achieved through the circulation of coolant.

[0049] In some embodiments of the high-precision screw pump for conveying high-viscosity materials provided in this application, please refer to... Figure 1 and Figure 2 The limiting body 5 is spirally wound on the outer wall of the bushing 4. The two ends of the connecting sleeve 3 are respectively equipped with an inlet pipe 6 and an outlet pipe 7. The limiting body 5 rotates relative to the bushing 4 to transport the liquid discharged by the inlet pipe 6 to the outlet pipe 7.

[0050] In some special cases, two transfer pumps are required to transport two liquids. However, the cost of purchasing two transfer pumps is relatively high, and they also occupy a certain amount of space. To solve this problem, in this application, the limiting body 5 is spirally wound around the outer wall of the bushing 4. At this time, the side of the limiting body 5 away from the bushing 4 will abut against the inner wall of the connecting sleeve 3. The limiting body 5, the bushing 4, and the connecting sleeve 3 together form a screw conveyor.

[0051] In practical applications, liquid can be transported between bushing 4 and connecting sleeve 3 through inlet pipe 6. At this time, bushing 4 drives limit body 5 to move, which can transport liquid to one side of outlet pipe 7, and finally complete the liquid transport.

[0052] In some embodiments of the high-precision screw pump for conveying high-viscosity materials provided in this application, the limiting body 5 and the bushing 4 are integrally formed.

[0053] By using an integral molding design, the connection strength between the limiting body 5 and the bushing 4 can be improved, thereby avoiding the risk of plastic deformation or even breakage between the limiting body 5 and the bushing 4.

[0054] In practical applications, in order to improve the sealing between the limiting body 5 and the connecting sleeve 3, a sealing gasket can be set along the length of the outer side of the limiting body 5. The sealing gasket has a certain wear resistance and the ability to expand and contract. By setting the sealing gasket, the collision between the limiting body 5 and the connecting sleeve 3 under the action of the screw shaft 2 can be reduced, thus ensuring the stability of the entire screw pump.

[0055] In some embodiments of the high-precision screw pump for conveying high-viscosity materials provided in this application, please refer to... Figure 2 and Figure 3 Cooling grooves 12 are spirally provided along the outer wall of bushing 4.

[0056] Screw pumps offer good economic performance, high and uniform pressure and flow rate, high speed, and can be directly connected to a prime mover. They can transport various oils and high-molecular polymers. Screw pumps can be classified by the number of screws: single-screw pumps, twin-screw pumps, and three-screw pumps. Single-screw pumps, due to the special geometry of their rotor and stator, form separate sealed cavities, making them suitable for transporting high-viscosity fluids and media containing hard suspended particles or fibers. However, existing single-screw pumps experience friction between the rotor and stator during operation, generating a large amount of heat. Since single-screw pumps generally have poor thermal conductivity, heat dissipation is difficult, leading to an increase in pump body temperature.

[0057] Screw vacuum pumps generate a significant amount of heat during operation, necessitating the installation of cooling chambers throughout their casing. These chambers are connected to heat exchangers via heat pipes, allowing for convective heat exchange between air and water, or between chilled water and water. However, existing cooling methods are ineffective at quickly removing heat, resulting in a buildup of heat in the screw vacuum pump and consequently reduced pumping efficiency.

[0058] In traditional single-screw pumps, the screw shaft 2 can be approximated as a helical rod. A helical structure is then installed inside the bushing 4. The liquid is transported through the cooperation between the screw and the bushing 4. The working surface of the existing bushing 4 is the inner wall, so the outer wall of the bushing 4 does not require machining. For ease of installation and fixation, the existing bushing 4, i.e., the outer side of the stator, is usually a cylindrical structure, meaning the thickness of the bushing 4 is not uniform in the circumferential direction. This inconsistent thickness results in some areas of the bushing 4 having stronger heat dissipation capabilities than others.

[0059] However, in order to improve the heat dissipation capacity of the entire bushing 4, a cooling groove 12 is spirally arranged along the outer wall of the bushing 4. In an extreme case, after the cooling groove 12 is opened on the bushing 4, the thickness of each angle on the cross section of the bushing 4 is consistent, so that the heat dissipation effect of each angle of the bushing 4 is the same. The above approach improves the cooling effect of the coolant.

[0060] Meanwhile, due to the presence of the cooling tank 12, the movement of the spiral teeth driven by the bushing 4 can increase the liquid transport between the bushing 4 and the connecting sleeve 3, that is, the amount of liquid that the bushing 4 can transport in one rotation relative to the connecting sleeve 3.

[0061] In some embodiments of the high-precision screw pump for conveying high-viscosity materials provided in this application, please refer to... Figure 1 A flow meter 10 is installed on the motor 1. The flow meter 10 is located at the liquid inlet end of the screw shaft 2 to detect the flow rate of the material. The flow meter 10 is electrically connected to a controller, which is electrically connected to the motor and the driver and the motor 1 to adjust the speed of the motor 1 and the motor.

[0062] If the material is interrupted during transport, and the screw shaft 2 continues to rotate relative to the bushing 4, the end result will be that the screw shaft 2 and the bushing 4 will heat up. If the heat cannot be dissipated quickly, it will inevitably aggravate wear.

[0063] To solve the above problems, a flow meter 10 is installed at the liquid inlet end of the screw shaft 2 in this application. The flow meter 10 will transmit the detected data to the controller in real time. When the controller determines that the current material conveying is interrupted based on the feedback data, it controls the motor 1 and the electric motor to rotate simultaneously, or makes the motor 1 and the electric motor move synchronously but at low speed. By using the above method, the problem of high temperature wear can be avoided.

[0064] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-precision screw pump for conveying high-viscosity materials, characterized in that, include: Electric motor; The screw shaft is connected to the motor drive. A connecting sleeve is fitted onto the outside of the screw shaft, and the connecting sleeve is fitted onto one side of the motor and used to fix it to the support surface; A bushing is rotatably disposed between the connecting sleeve and the screw shaft, and the bushing cooperates with the screw shaft to transport materials; A driver, fixed to the connecting sleeve and connected to the bushing in a transmission manner, is used to drive the bushing to rotate in the opposite direction relative to the screw shaft; With the relative speed between the screw shaft and the bushing remaining constant, the driver is used to reduce the output power of the motor; The driver includes a worm gear and a worm. The worm gear is fitted on the outer wall of the bushing, and a motor is mounted on the connecting sleeve. The worm is mounted on the output shaft of the motor and drives the worm gear. A transmission sleeve is fixed to the end of the bushing near the motor, and the worm gear is mounted on the transmission sleeve; The end of the connecting sleeve near the motor is provided with a limiting sleeve, and the limiting sleeve is sealed against the transmission sleeve.

2. The high-precision screw pump for conveying high-viscosity materials as described in claim 1, characterized in that, A limiting body is provided between the bushing and the connecting sleeve, and the bushing and the connecting sleeve form a flow channel by means of the limiting body.

3. The high-precision screw pump for conveying high-viscosity materials as described in claim 2, characterized in that, The limiting body includes multiple rolling elements.

4. The high-precision screw pump for conveying high-viscosity materials as described in claim 2, characterized in that, The limiting body is spirally wound around the outer wall of the bushing, and the two ends of the connecting sleeve are respectively equipped with an inlet pipe and an outlet pipe. The limiting body rotates relative to the bushing to transport the liquid discharged by the inlet pipe to the outlet pipe.

5. The high-precision screw pump for conveying high-viscosity materials as described in claim 4, characterized in that, The limiting body and the bushing are integrally formed.

6. The high-precision screw pump for conveying high-viscosity materials as described in claim 1, characterized in that, Cooling grooves are spirally provided along the outer wall of the bushing.

7. The high-precision screw pump for conveying high-viscosity materials as described in claim 1, characterized in that, A flow meter is installed at the inlet end of the screw shaft to detect the flow rate of the material; and the flow meter is connected to a controller, which is electrically connected to the motor and the electric motor to adjust the speed of the motor and the electric motor.

Images