Differential pump with anti-cavitation function

Abstract

The application discloses a differential pump with anti-cavitation function, which comprises a shell, a differential device and a power device, wherein a front impeller is arranged in the shell, and a rear impeller is arranged for discharging fluid, and the front impeller is used for compressing fluid to the rear impeller; the differential device is arranged between the front impeller and the rear impeller, so that the rotating speed of the front impeller is lower than that of the rear impeller; the differential device is connected with the front impeller and the rear impeller through a transmission shaft, and the power device is transmissionally connected with the transmission shaft. The front impeller is arranged to cooperate with the differential device to guide and pressurize fluid, a stable pressure field is formed at the rear impeller by the front impeller, and the stable pressure field is always higher than the medium vaporization pressure, thereby blocking the cavitation occurrence condition, and the special material coating is not needed, so that the manufacturing cost can be greatly reduced.

Description

Technical Field

[0001] This application relates to the field of industrial pump technology, and in particular to a differential pump with anti-cavitation function. Background Technology

[0002] In the field of industrial pumps, cavitation has long constrained the reliability and efficiency of pumps under high-pressure and high-speed conditions. When the local pressure of the fluid is lower than the saturated vapor pressure, cavitation bubbles are generated and collapse, leading to erosion of the impeller surface material, increased vibration, and performance degradation. Traditional centrifugal pumps (such as the cantilever centrifugal pump with announcement number CN217682310U for small flow and high head) experience turbulent flow and uneven pressure distribution at the impeller inlet during operation. Especially when conveying easily vaporized media (such as high-temperature water and liquid hydrocarbons), the impeller is more prone to cavitation, resulting in shortened equipment life or even failure. Utility Model Content

[0003] To address the aforementioned technical problems, this application provides a differential pump with anti-cavitation function. By setting a front impeller to guide and pressurize the fluid, it replaces traditional material protection methods, thereby blocking the conditions for cavitation to occur. The technical solution is as follows:

[0004] A differential pump with anti-cavitation function includes a housing and a power unit. The housing is provided with a front impeller and a rear impeller for discharging fluid. The front impeller is used to compress the fluid toward the rear impeller.

[0005] A differential device, wherein the front impeller and the rear impeller are positioned such that the rotational speed of the front impeller is lower than that of the rear impeller;

[0006] The differential device is connected to the front impeller and the rear impeller via a drive shaft, and the power device is driven by the drive shaft.

[0007] Preferably, the housing includes an inlet section, a transition section, and an outlet section, with the front impeller located at the inlet section and the rear impeller located at the outlet section.

[0008] More preferably, the transition section has a tapered structure. This further accelerates the fluid and homogenizes the circumferential velocity distribution, preventing cavitation caused by sudden changes in flow velocity.

[0009] More preferably, the liquid inlet section has a funnel-shaped structure.

[0010] More preferably, the transition section is provided with a plurality of guide vanes. These vanes are used to eliminate circumferential velocity and guide the fluid into the rear impeller in a laminar flow state.

[0011] Preferably, the drive shaft includes a first rotating shaft and a second rotating shaft, the first rotating shaft connecting the differential device and the front impeller, the second rotating shaft connecting the differential device and the rear gear, and the power device driving the second rotating shaft to rotate.

[0012] More preferably, the differential device includes a mounting base and a pair of series-connected reduction mechanisms disposed within the mounting base, the reduction mechanisms being respectively connected to the first rotating shaft and the second rotating shaft.

[0013] More preferably, the reduction mechanism includes a sun gear and a ring gear, and a plurality of planet gears disposed between the sun gear and the ring gear, the ring gear being connected to the mounting base, and the sun gear being connected to the first rotating shaft and the second rotating shaft respectively.

[0014] Preferably, the front impeller is provided with a serrated microstructure to optimize the pressure distribution near the outlet and reduce the formation of local low-pressure areas.

[0015] Compared with the prior art, the beneficial effects of this application are as follows:

[0016] (1) This application uses a front impeller and a differential device to guide and pressurize the fluid. The front impeller forms a stable pressure field at the rear impeller, which is always higher than the vaporization pressure of the medium, thereby blocking the conditions for cavitation. It does not require special material coatings and can significantly reduce manufacturing costs.

[0017] (2) By designing a differentiated rotation speed, turbulence loss is reduced, and laminar flow acceleration is achieved in conjunction with the gradually narrowing guide section, thereby improving pump efficiency and reducing energy consumption. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this application;

[0019] Figure 2 This is a schematic diagram of the differential device structure of this application.

[0020] In the picture:

[0021] 10. Shell; 110. Liquid inlet section; 120. Liquid outlet section; 130. Transition section;

[0022] 20. Rear impeller; 30. Front impeller;

[0023] 40. Differential gear; 410. Mounting base; 420. Sun gear; 430. Ring gear; 440. Star gear.

[0024] 50. Drive shaft; 51. First rotating shaft; 52. Second rotating shaft;

[0025] 60. Power unit. Detailed Implementation

[0026] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described in this application are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0027] See Figure 1 and Figure 2 To further elaborate on this application:

[0028] Combination Figure 1 A differential pump with anti-cavitation function includes a housing 10 and a power unit 60. The housing 10 is provided with a front impeller 30 and a rear impeller 20 for discharging fluid. The front impeller 30 is used to compress the fluid towards the rear impeller 20. The front impeller 30 is an axial flow impeller, and the rear impeller 20 is a centrifugal impeller. In this embodiment, the diameter of the front impeller 30 is larger than the diameter of the rear impeller 20.

[0029] A differential device 40 is provided between the front impeller 30 and the rear impeller 20, ensuring that the rotational speed of the front impeller 30 is lower than that of the rear impeller 20. In this embodiment, the transmission ratio of the differential device 40 is a standard 1:1.8 transmission ratio. Of course, the transmission ratio can be adjusted as needed, and this is not limited here. The front impeller 30 compresses the fluid it draws in towards the rear impeller 20, which then drives the fluid to be discharged.

[0030] The differential device 40 is connected to the front impeller 30 and the rear impeller 20 via a drive shaft 50, and the power device 60 is connected to the drive shaft 50.

[0031] This application uses the front impeller 30 in conjunction with the differential speed device 40 to guide and pressurize the fluid, pre-compressing the incoming flow and increasing the fluid pressure energy. When the rear impeller 20 rotates at high speed, a stable pressure field is formed at its inlet due to the rectification effect of the front impeller 30, ensuring that the minimum local pressure is always higher than the vaporization pressure of the medium, thereby blocking the conditions for cavitation to occur. This eliminates the need for special material coatings and can significantly reduce manufacturing costs.

[0032] In this embodiment, the housing 10 includes an inlet section 110, a transition section 130, and an outlet section 120. The front impeller 30 is located at the inlet section 110, and the rear impeller 20 is located at the outlet section 120. The inlet section has a funnel-shaped structure; the transition section 130 has a tapered structure, meaning its diameter gradually decreases along the fluid flow direction, which increases the fluid velocity and prevents cavitation caused by sudden changes in flow velocity.

[0033] In some embodiments, the front impeller 30 is provided with a serrated microstructure (not shown). The serrated microstructure is located at the blade outlet edge of the front impeller 30, and is used to optimize the pressure distribution near the outlet and reduce the formation of local low-pressure areas.

[0034] The drive shaft 50 includes a first rotating shaft 51 and a second rotating shaft 52. The first rotating shaft 51 connects the differential device 40 and the front impeller 30, and the second rotating shaft 52 connects the differential device 40 and the rear gear. The power unit 60 drives the second rotating shaft 52 to rotate. The power unit 60 is an electric motor; the power unit 60 can be connected to the second rotating shaft 52 via conventional transmission methods such as belt drive or coupling.

[0035] During operation, the second rotating shaft 52 is driven to rotate by the power device 60, which in turn drives the rear impeller 20, the differential device 40, the first rotating shaft 51 and the front impeller 30 to rotate in sequence. The differential device 40 regulates the speed between the front impeller 30 and the rear impeller 20 so that the front impeller 30 pre-compresses the fluid first, and then the rear impeller 20 discharges the fluid.

[0036] The differential device 40 includes a mounting base 410 and a pair of series-connected reduction mechanisms disposed in the mounting base 410, for connecting the first rotating shaft 51 and the second rotating shaft 52 respectively, and transmitting power through the mounting base 410.

[0037] Each reduction mechanism includes a sun gear 420 and a ring gear 430, and a plurality of planet gears 440 disposed between the sun gear 420 and the ring gear 430. The ring gear 430 is connected to the mounting base 410, and the sun gear 420 is connected to the first rotating shaft 51 and the second rotating shaft 52 respectively. The differential device 40 is sealed to the first rotating shaft 51 and the second rotating shaft 52 to prevent fluid from entering the differential device 40.

[0038] In one embodiment, the inner wall of the transition section 130 is provided with a plurality of guide vanes (not shown) to ensure that the fluid enters the rear impeller 20 in a laminar flow state.

[0039] In some embodiments, the front impeller 30 is provided with a flow guide on both sides; the differential device 40 may be arranged inside the flow guide.

Claims

1. A differential pump with anti-cavitation function, comprising a housing and a power unit, characterized in that: The housing is provided with a front impeller and a rear impeller for discharging fluid, the front impeller being used to compress the fluid toward the rear impeller; A differential device, wherein the front impeller and the rear impeller are positioned such that the rotational speed of the front impeller is lower than that of the rear impeller; The differential device is connected to the front impeller and the rear impeller via a drive shaft, and the power device is driven by the drive shaft.

2. The differential pump with anti-cavitation function according to claim 1, characterized in that: The housing includes an inlet section, a transition section, and an outlet section. The front impeller is located in the inlet section, and the rear impeller is located in the outlet section.

3. The differential pump with anti-cavitation function according to claim 2, characterized in that: The transition section has a tapered structure.

4. The differential pump with anti-cavitation function according to claim 2, characterized in that: The liquid inlet section has a funnel-shaped structure.

5. The differential pump with anti-cavitation function according to claim 2, characterized in that: The transition section is equipped with several guide vanes.

6. The differential pump with anti-cavitation function according to claim 1, characterized in that: The drive shaft includes a first rotating shaft and a second rotating shaft. The first rotating shaft connects the differential device and the front impeller, and the second rotating shaft connects the differential device and the rear gear. The power device is used to drive the second rotating shaft to rotate.

7. The differential pump with anti-cavitation function according to claim 6, characterized in that: The differential device includes a mounting base and a pair of series-connected reduction mechanisms disposed within the mounting base, the reduction mechanisms being connected to the first rotating shaft and the second rotating shaft respectively.

8. The differential pump with anti-cavitation function according to claim 7, characterized in that: The reduction mechanism includes a sun gear and a ring gear, and a plurality of planet gears disposed between the sun gear and the ring gear. The ring gear is connected to the mounting base, and the sun gear is connected to the first rotating shaft and the second rotating shaft respectively.

9. The differential pump with anti-cavitation function according to claim 1, characterized in that: The front impeller is provided with a sawtooth-shaped microstructure.

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