Vertical three-screw pump

Abstract

The utility model discloses a vertical three-screw pump, which belongs to the technical field of screw pumps and comprises a pump head, a safety valve is arranged on the pump head, a connecting frame is arranged on the upper end face of the pump head, a motor used for driving the pump head is arranged on the upper end face of the connecting frame, and a base is arranged on the inner side of the connecting frame. A filter is arranged at the lower end of the base, oil liquid of an external oil conveying pipeline is filtered by the filter, surrounds the pump by one circle through a base pipeline of the base and then enters the pump head, and the high-pressure medium low-noise pump can be suitable for low-noise conveying of high-pressure media and is stable in operation and extremely small in vibration and noise.

Description

Technical Field

[0001] This utility model belongs to the field of screw pump technology, and particularly relates to a vertical three-screw pump. Background Technology

[0002] In the field of marine electromechanical equipment, flow noise, propulsion system noise, and mechanical vibration noise constitute the main components of ship radiated noise. Especially during low-speed navigation, the noise contributed by electromechanical equipment accounts for as much as 70% of the total ship radiated noise, highlighting the crucial importance of improving the acoustic performance of these devices in reducing the overall vibration noise of the ship.

[0003] Three-screw pumps, with their unique axial conveying capacity and extremely low shear and destructive effects on the medium, have a wide range of applications in various marine oil systems. Their excellent structure ensures that the air noise during operation is effectively controlled to a low level of less than 70dB.

[0004] However, the operating pressure of most high-pressure, low-noise vertical three-screw pumps currently on the market is limited to around 4 MPa. This is far from meeting the operational requirements of a ship's hydraulic system as a core hydraulic power source at operating pressures up to 10 MPa, while maintaining low noise levels. Traditionally, to increase the discharge pressure of a three-screw pump, it is often necessary to increase the length of the master and slave screws or reduce the lead. However, these practices not only significantly increase the manufacturing complexity of the master and slave screws but may also sacrifice the pump's volumetric efficiency. More seriously, the strong impact of the high-pressure medium on the pump head can easily trigger turbulence within the pump, thereby exacerbating pump vibration and noise and increasing the risk of failure. Therefore, developing a vertical three-screw pump that can withstand high pressure while maintaining low noise characteristics has become a critical technical challenge that urgently needs to be solved. Summary of the Invention

[0005] To address the problems existing in the prior art, this utility model provides a vertical three-screw pump that is suitable for low-noise transportation of high-pressure media, and operates smoothly with minimal vibration and noise.

[0006] This utility model is implemented as follows: This application provides a vertical three-screw pump, including a pump head, a safety valve, a connecting frame on the upper surface of the pump head, a motor on the upper surface of the connecting frame, a base on the inner side of the connecting frame, and a filter at the lower end of the base. Oil from the external oil pipeline is filtered by the filter and then enters the pump head after passing through the base pipe of the base and circulating around the pump once.

[0007] Furthermore, the pump head includes a pump body arranged vertically, with a pump outlet at the upper end and a pump inlet at the lower end; a screw bushing is provided inside the pump body, and a driving screw and two driven screws meshing on both sides of the driving screw are provided inside the screw bushing, with a screw bushing fitted on the outer side of the driven screw; a balance sleeve is fitted on the upper end of the driven screw, and the balance sleeve is fixed to the screw bushing by a pin;

[0008] A front cover is provided on the pump body end face near the pump outlet side, and a stuffing box is provided on the top of the front cover. One end of the drive screw extends outward through the sealing cavity of the pump body, the front cover and the stuffing box in sequence.

[0009] Furthermore, a return oil chamber is provided inside the side wall of the stuffing box, and the return oil chamber is connected to the sealing cavity of the stuffing box. The inlet end of the return oil chamber abuts against a valve ball. A return oil valve plug is provided in the return oil chamber located on the same axis as the valve ball. A return oil valve spring is provided between the return oil valve plug and the valve ball. A return oil channel is provided on the front cover. One end of the return oil channel is connected to the return oil chamber, and the other end is connected to the inlet cavity of the screw bushing.

[0010] Furthermore, a bearing fitted onto the drive screw is provided inside the front cover, and a mechanical seal fitted onto the drive screw is provided inside the sealing cavity of the stuffing box. An elastic retaining ring and a support washer are installed between the mechanical seal and the bearing.

[0011] Furthermore, the safety valve includes a valve body, one end of which is threadedly connected to a valve connector. A check valve is installed inside the valve body near the valve connector. A communicating chamber is connected to an opening on the valve body at the upper end of the check valve. The safety valve communicates with the pump head through the communicating chamber. A safety valve plug is installed on the valve body opposite the valve connector mounting end. A valve connector is installed on the valve body near the safety valve plug. A valve seat is installed inside the valve body near the valve connector. A valve spring is installed at one end of the valve seat. A sleeve is sleeved on the outside of the valve spring. A guide sleeve is installed at the end of the sleeve near the safety valve plug. An adjusting rod is installed on the guide sleeve. The adjusting rod extends through the safety valve plug to the outside of the valve body. An adjusting nut is installed on the adjusting rod outside the valve body.

[0012] Furthermore, the filter includes a filter sleeve, a filter flange is provided on the upper end face of the filter sleeve, a filter upper cover is provided on the upper end of the filter flange, a filter lower cover is provided on the lower end face of the filter sleeve, a filter outlet sleeve is provided at the lower end of the filter lower cover, the filter outlet sleeve is connected to the filter sleeve, and a filter screw plug is provided at the lower end of the filter outlet sleeve.

[0013] The filter outlet sleeve is connected to a filter outlet pipe, which is connected to the base pipe on the right side of the base. The filter inlet sleeve is connected to the side wall of the filter sleeve, and a filter inlet flange is provided at the top of the filter inlet sleeve, which is connected to an external pipe.

[0014] Furthermore, the connecting frame includes a connecting frame flange, the pump head and the motor are respectively installed at both ends of the connecting frame flange, two connecting frame baffles are welded to the lower part of the connecting frame flange, and a connecting frame base is welded to the bottom of the connecting frame baffles.

[0015] Furthermore, the base includes a base pipe, on which multiple base plates are evenly distributed along the axis of the base pipe, a base connecting pipe is connected in the middle of the base pipe, and a filter connecting plate for fixing the filter is installed at the bottom of the base.

[0016] The advantages and technical effects of this utility model are as follows: Due to the adoption of the above technical solution and the integrated design concept of inlet and outlet pipelines and base, this innovation not only significantly reduces the number of components of the pump and lowers the production cost, but also effectively avoids vibration problems that may be caused by a large number of parts, thereby further improving the smooth operation of the pump.

[0017] Furthermore, our specially designed oil return structure is one of the highlights of this invention. This structure allows the oil at the mechanical seal to flow smoothly through the oil return pipe to the low-pressure chamber of the pump head, ensuring pressure balance between the mechanical seal and the low-pressure chamber. This design not only significantly improves the wear resistance of the three-screw pump and effectively protects the mechanical seal, reducing oil leakage, but also ensures that high-pressure oil can be discharged normally from the pressure port, thereby greatly extending the pump's service life.

[0018] In summary, this invention is not only suitable for low-noise transportation of high-pressure media, but also has won widespread market recognition due to its stable operation and minimal vibration and noise. Its compact overall structure and few parts make disassembly and maintenance extremely convenient. This is particularly true in environments with limited space and strict requirements on vibration, noise, dimensions, and weight. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a vertical three-screw pump according to the present invention.

[0020] Figure 2 This is a structural diagram of the pump head of a vertical three-screw pump according to the present invention.

[0021] Figure 3 This is a structural diagram of the safety valve of a vertical three-screw pump according to the present invention.

[0022] Figure 4 This is a structural diagram of the filter of a vertical three-screw pump according to the present invention.

[0023] Figure 5 This is a structural diagram of the connecting frame of a vertical three-screw pump according to the present invention.

[0024] Figure 6 This is a structural diagram of the base of a vertical three-screw pump according to the present invention.

[0025] The attached diagram is labeled as follows: 1. Pump head; 2. Safety valve; 3. Connecting frame; 4. Motor; 5. Base; 6. Filter; 7. Driving screw; 8. Driven screw; 9. Screw bushing; 10. Pump body; 11. Stuffing box; 12. Elastic retaining ring; 13. Support washer; 14. Bearing; 15. Front cover; 16. Pin; 17. Key; 18. Mechanical seal; 19. Valve ball; 20. Return valve plug; 21. Balance sleeve; 22. Pump outlet; 23. Pump inlet; 24. Rear cover; 25. Cap; 26. Safety valve plug; 27. Adjusting rod; 28. Guide sleeve; 29. ​​Valve connection pipe; 30. 31. Sleeve; 32. Valve spring; 33. Valve body; 34. Check valve; 35. Valve connector; 36. Filter inlet flange; 37. Filter inlet sleeve; 38. Filter outlet sleeve; 39. Filter plug; 40. Filter top cover; 41. Filter flange; 42. Filter sleeve; 43. Filter bottom cover; 44. Filter outlet pipe; 45. Connecting frame flange; 46. Connecting frame baffle; 47. Connecting frame base; 48. Base pipe; 49. Base small plate; 50. Base pipe; 51. Filter connecting plate; 52. Valve seat; 53. Adjusting nut; 54. Connecting chamber; 55. Return valve spring. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0027] It should be noted that the terms "upper", "lower", "left", "right", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0028] like Figure 1As shown, this application provides a vertical three-screw pump, including a pump head 1, a safety valve 2 provided on the pump head, an opening on the inner side of the upper part of the pump head, the pump head being connected to the safety valve through a communicating chamber in the opening of the safety valve, a connecting frame 3 provided on the upper end face of the pump head, a motor 4 for driving the pump head provided on the upper end face of the connecting frame, a base 5 provided on the inner side of the connecting frame, and a filter 6 provided at the lower end of the base. The oil from the external oil pipeline is filtered by the filter and then enters the pump head after passing through the base pipe of the base and circulating around the pump once.

[0029] like Figure 2 As shown, the pump head 1 includes a pump body 10 arranged vertically, with a pump outlet 22 at the upper end and a pump inlet 23 at the lower end; a screw bushing 9 is provided inside the pump body, and a driving screw 7 and two driven screws 8 meshing on both sides of the driving screw are provided inside the screw bushing, with the screw bushing 9 sleeved on the outer side of the driven screw; a balance sleeve 21 is sleeved on the upper end of the driven screw, and the balance sleeve is fixed to the screw bushing by a pin 16;

[0030] A front cover 15 is provided on the end face of the pump body 10 near the pump outlet. A stuffing box 11 is provided at the top of the front cover. One end of the drive screw extends outward through the sealing cavity of the pump body, the front cover and the stuffing box and is connected to the motor. The extended end of the drive screw is connected to the motor through a key 17. A bearing 14 is provided inside the front cover and fitted onto the drive screw. A mechanical seal 18 is provided inside the sealing cavity of the stuffing box and fitted onto the drive screw 7. An elastic retaining ring 12 and a support washer 13 are installed between the mechanical seal and the bearing. The elastic retaining ring provides axial positioning for the mechanical seal and prevents the mechanical seal from falling off. The support washer separates the mechanical seal from the bearing and reduces friction loss.

[0031] The stuffing box 11 has a return oil chamber in its side wall, which is connected to the sealing chamber. The inlet end of the return oil chamber abuts against a valve ball 19. A return oil valve plug 20 is provided in the return oil chamber located on the same axis as the valve ball. A return oil valve spring 54 is provided between the return oil valve plug and the valve ball. The front cover 15 has a return oil channel, one end of which is connected to the return oil chamber and the other end of which is connected to the inlet cavity of the screw bushing.

[0032] A rear cover 24 is provided on the pump body end face near the pump inlet side.

[0033] like Figure 3As shown, the safety valve 2 includes a valve body 32, one end of which is threadedly connected to a valve connector 34. A check valve 33 is installed inside the valve body near the valve connector. A communicating chamber 53 is connected to an opening on the valve body at the upper end of the check valve. The safety valve is connected to the pump head 1 through the communicating chamber. A safety valve plug 26 is installed on the valve body opposite the valve connector mounting end. A valve connector 29 is installed on the valve body near the safety valve plug. A valve seat 51 is installed inside the valve body near the valve connector. A valve spring 31 is installed at one end of the valve seat. A sleeve 30 is sleeved on the outside of the valve spring. A guide sleeve 28 is installed at the end of the sleeve near the safety valve plug. An adjusting rod 27 is installed on the guide sleeve. The adjusting rod extends through the safety valve plug to the outside of the valve body. An adjusting nut 52 is installed on the adjusting rod outside the valve body. A cap 25 is sleeved on the adjusting rod outside the valve body.

[0034] like Figure 4 As shown, the filter 6 includes a filter sleeve 41, a filter flange 40 is provided on the upper end face of the filter sleeve, a filter upper cover 39 is provided on the upper end of the filter flange, a filter lower cover 42 is provided on the lower end face of the filter sleeve, a filter outlet sleeve 37 is provided at the lower end of the filter lower cover, the filter outlet sleeve is connected to the filter sleeve, and a filter screw plug 38 is provided at the lower end of the filter outlet sleeve.

[0035] The filter outlet sleeve is connected to a filter outlet pipe 43, which is connected to the base pipe on the right side of the base. After the oil enters the right pipe and flows around the pump once, it enters the pump head from the base pipe on the left side of the base. The side wall of the filter sleeve is connected to a filter inlet sleeve, and the top of the filter inlet sleeve 36 is provided with a filter inlet flange 35, which is connected to an external pipe.

[0036] like Figure 5 As shown, the connecting frame 3 includes a connecting frame flange 44. The pump head 1 and the motor 4 are respectively installed at both ends of the connecting frame flange 44. Two connecting frame baffles 45 are welded to the lower part of the connecting frame flange. A connecting frame base 46 is welded to the bottom of the connecting frame baffle. The connecting frame baffles serve to support the connecting frame flange and the connecting frame base.

[0037] like Figure 6 As shown, the base 5 includes a base pipe 49, on which multiple base plates 48 are evenly distributed along the axis of the base pipe. Specifically, there are eight base plates. The connecting frame base is welded and fixed to the base plates. A base connector 47 is connected to the middle of the base pipe. Oil from the external pipeline enters the base connector, which can make the liquid flow smoothly and reduce the vibration and noise of the pump. A filter plate 50 for fixing the filter is installed at the bottom of the base. The filter plate is used to fix the filter.

[0038] Working process: During operation, the vertical three-screw pump propels the medium forward by the continuous rotation of the drive screw and driven screw within the screw bushing. The drive screw and driven screw are arranged parallel inside the screw bushing. The drive screw is driven by a motor, while the driven screw is driven by hydraulic force to rotate in the opposite direction. When the drive screw rotates, the sealing line between the drive screw and driven screw forms a series of sealed chambers. In the initial stage of screw rotation, the inlet end of the sealed chamber gradually increases, forming a low-pressure area, thereby drawing in the medium to be transported. As the oil moves to the outlet end of the sealed chamber with the rotation of the drive screw and driven screw, the pressure of the oil increases due to the decrease in the volume of the sealed chamber. After being pressurized through multiple sealed chambers, the oil is discharged from the pump body in a high-pressure state.

[0039] The oil flowing out of the pump head enters the safety valve through the valve connector. When the oil pressure is below the limit value, the oil will push the check valve to open and flow out along the valve joint. When the pressure of the liquid on the safety valve increases and exceeds the force of the safety valve spring, the valve seat will be pushed open, and the high-pressure oil will flow out from the two channels of the valve joint and the valve connector, thus reducing the pressure of the oil that is forced out.

[0040] Thanks to the above-mentioned technical solution and the integrated design of the inlet and outlet pipelines and the base, this innovation not only significantly reduces the number of pump components and lowers production costs, but also effectively avoids vibration problems that may be caused by a large number of parts, thereby further improving the pump's operational stability.

[0041] Furthermore, our specially designed oil return structure is one of the highlights of this invention. This structure allows the oil at the mechanical seal to flow smoothly through the oil return pipe to the low-pressure chamber of the pump head, ensuring pressure balance between the mechanical seal and the low-pressure chamber. This design not only significantly improves the wear resistance of the three-screw pump and effectively protects the mechanical seal, reducing oil leakage, but also ensures that high-pressure oil can be discharged normally from the pressure port, thereby greatly extending the pump's service life.

[0042] In summary, this invention is not only suitable for low-noise transportation of high-pressure media, but also has won widespread market recognition due to its stable operation and minimal vibration and noise. Its compact overall structure and few parts make disassembly and maintenance extremely convenient. This is particularly true in environments with limited space and strict requirements on vibration, noise, dimensions, and weight.

[0043] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A vertical triple screw pump characterized in that, Including pump head, be provided with safety valve on the pump head, the upper end surface of the pump head is provided with connecting frame, the upper end surface of the connecting frame is provided with motor for driving pump head, the inner side of the connecting frame is provided with base, the lower end of the base is provided with filter, the oil liquid of external oil pipeline is filtered through the filter and enters the pump head through the base pipeline around the pump.

2. The vertical three-screw pump according to claim 1, characterized in that, The pump head comprises a pump body arranged in a vertical direction, an upper end of the pump body is provided with a pump outlet, and a lower end of the pump body is provided with a pump inlet; a screw bushing is arranged in the pump body, a driving screw and two driven screws meshing on both sides of the driving screw are arranged in the screw bushing, and the outer side of the driven screw is sleeved with the screw bushing; a balance sleeve is sleeved on the upper end of the driven screw, and the balance sleeve is fixed with the screw bushing through a pin; A front cover is arranged on the end surface of the pump body near the pump outlet side, a top end of the front cover is provided with a stuffing box, and an end of the driving screw penetrates a sealing cavity of the pump body, the front cover and the stuffing box in sequence and extends outward.

3. The vertical three-screw pump according to claim 2, characterized in that, An oil return cavity is arranged in the side wall of the stuffing box, the oil return cavity is communicated with the sealing cavity of the stuffing box, a valve ball abuts against an inlet end of the oil return cavity, an oil return valve plug is arranged in the oil return cavity coaxially with the valve ball, an oil return valve spring is arranged between the oil return valve plug and the valve ball, an oil return channel is arranged on the front cover, one end of the oil return channel is communicated with the oil return cavity, and the other end of the oil return channel is communicated with an inlet cavity of the screw bushing.

4. The vertical three-screw pump according to claim 2, characterized in that, A bearing is arranged in the front cover and sleeved on the driving screw, a mechanical seal is arranged in the sealing cavity of the stuffing box and sleeved on the driving screw, and an elastic retainer ring and a support washer are arranged between the mechanical seal and the bearing.

5. The vertical three-screw pump of claim 1, wherein, The safety valve comprises a valve body, a valve joint is threadedly connected to one end of the valve body, a check valve is arranged in the valve body near the valve joint, a communication chamber is connected to an opening in the valve body at the upper end of the check valve, the safety valve is communicated with the pump head through the communication chamber, a safety valve plug is arranged on the valve body opposite the valve joint mounting end, a valve connecting pipe is arranged on the valve body near the safety valve plug, a valve seat is arranged in the valve body near the valve connecting pipe, a valve spring is arranged at one end of the valve seat, a sleeve is sleeved on the outer side of the valve spring, a guide sleeve is arranged at the end of the sleeve near the safety valve plug, an adjusting rod is arranged on the guide sleeve, the adjusting rod penetrates the safety valve plug and extends outward from the valve body, and an adjusting nut is arranged on the adjusting rod outside the valve body.

6. The vertical three-screw pump of claim 1, wherein, The filter comprises a filter sleeve, a filter flange is arranged on the upper end surface of the filter sleeve, a filter upper cover is arranged on the upper end of the filter flange, a filter lower cover is arranged on the lower end surface of the filter sleeve, a filter outlet sleeve is arranged on the lower end of the filter lower cover, the filter outlet sleeve is communicated with the filter sleeve, and a filter plug is arranged on the lower end of the filter outlet sleeve. A filter outlet connecting pipe is arranged in communication on the filter outlet sleeve, the filter outlet connecting pipe is communicated with the base pipeline on the right side of the base, a filter inlet sleeve is arranged in communication on the side wall of the filter sleeve, a filter inlet flange is arranged on the top end of the filter inlet sleeve, and the filter inlet flange is communicated with an external pipeline.

7. The vertical three-screw pump of claim 1, wherein The connecting frame comprises a connecting frame flange, the pump head and the motor are respectively installed at two ends of the connecting frame flange, two connecting frame baffles are welded at lower portions of the connecting frame flange, and a connecting frame base is welded at bottom portions of the connecting frame baffles.

8. The vertical three-screw pump of claim 1, wherein, The base comprises a base pipe, a plurality of base small plates are uniformly distributed on the base pipe along a base pipe axis, a base connecting pipe is connected to a middle portion of the base pipe, and a filter connecting plate for fixing the filter is installed at a bottom portion of the base.

Images