CN205714923U - A kind of diagonal pumps - Google Patents

Abstract

The utility model provides an oblique flow pump, which comprises a pump shaft, an inlet section, a cylindrical outer cylinder and an elbow section, the pump shaft passes through the cylindrical outer cylinder and the elbow section, and the pump shaft is installed There are blades, the inner wall of the inlet section is composed of two parts: the wall of the inlet chamber and the wall of the runner chamber, the wall of the inlet chamber is a conical surface, the wall of the runner chamber is an arc surface, and the wall of the runner chamber The inner wall of the cylindrical outer cylinder is tangent; the blade is located in the runner chamber of the inlet section, and an annular groove is formed at the junction of the inlet chamber wall and the runner chamber wall. The inclined flow pump of the utility model can weaken the intensity of the leakage flow at the tip of the blade at the inlet, reduce its influence on the internal flow of the impeller, improve the performance of the inclined flow pump, effectively suppress the appearance of the "hump" area and improve the performance of the inclined flow pump. Running stability.

Description

A Diagonal Flow Pump

technical field

The utility model relates to an oblique flow pump, in particular to an oblique flow pump with large flow rate, low lift and wide high-efficiency area.

Background technique

The specific speed of the diagonal flow pump is higher, and the performance is between the axial flow pump and the centrifugal pump. Therefore, the oblique flow pump has the advantages of both the axial flow pump and the centrifugal pump, that is, it has the advantages of a head variation range of 3~30m, a flat head and power curve, a wide high-efficiency area, good anti-cavitation performance, and easy start-up. It is used in agricultural irrigation and drainage, municipal water supply and drainage, South-to-North Water Diversion Project, power plant circulating water supply, regional water transfer and other fields. In recent years, it has gradually developed into nuclear power and ship water jet propulsion.

There is a gap between the rim of the impeller of the oblique flow pump and the runner chamber. When the impeller rotates, the static pressure on the pressure surface of the blade is higher than that on the suction surface. flow. The tip leakage flow interacts with the mainstream to form a tip leakage vortex, which will not only affect the internal flow state of the mixed flow pump, but also block the flow channel and affect the operation stability of the mixed flow pump. Under the condition of small flow rate, the angle of attack at the blade inlet increases, and the fluid is easy to flow and separate at the blade inlet suction surface to form a vortex. The static pressure value will decrease rapidly, which will increase the pressure difference between the pressure surface and the suction surface, and the leakage of the tip of the blade will increase, which will increase the flow instability inside the mixed flow pump. In addition, the leakage flow at the tip of the blade will increase the peripheral velocity component of the mainstream at the inlet rim of the adjacent blade, and the angle of attack at the inlet rim of the impeller will increase, causing the critical stall point of the mixed flow pump to shift to the direction of large flow, affecting the flow rate of the mixed flow pump. safe operation.

After searching, in terms of improving the stability of the diagonal flow pump, Jiangsu University "a hydraulic design method for the impeller of the diagonal flow pump" (application number: CN201410711980), the patent gives the design formula of the main geometric design parameters of the impeller, through this design method The hydraulic efficiency of the impeller of the inclined flow pump and the stability of the inclined flow pump are improved to a certain extent. This patent is to improve the slope and stability of the impeller from the aspect of the hydraulic design of the impeller, while this patent is to improve the stability of the inclined flow pump by slotting the wall of the runner chamber to weaken the leakage flow intensity of the blade tip and inhibit the impeller from stalling.

Utility model content

In order to reduce the impact of the blade tip leakage flow on the performance of the diagonal flow pump, especially to suppress the appearance of the "hump" area of the diagonal flow pump under the condition of small flow rate, and improve the operation stability of the diagonal flow pump, the utility model provides a simple High-efficiency, easy-to-process diagonal flow pump.

In order to achieve the purpose of the above utility model, the technical solution adopted by the utility model is: a diagonal flow pump, including a pump shaft, an inlet section, a cylindrical outer cylinder and an elbow section, the pump shaft passes through the cylindrical outer cylinder and the The elbow section, the pump shaft is equipped with blades, the inner cavity wall of the inlet section is composed of two parts: the inlet chamber wall and the runner chamber wall, the inlet chamber wall is conical, and the runner chamber wall It is an arc surface, the wall of the runner chamber is tangent to the inner wall of the cylindrical outer cylinder; the blade is located in the runner chamber of the inlet section, and an annular groove is opened at the junction of the wall of the inlet chamber and the runner chamber .

In the above solution, the impeller inlet edge of the blade is facing the junction of the wall surface of the inlet chamber and the wall surface of the runner chamber.

In the above solution, the longitudinal section of the annular groove is J-shaped.

In the above solution, a runner hub is installed on the pump shaft, and the blades are fixed on the runner hub by cylinder head screws.

In the above solution, the runner hub is also provided with a water guiding cone, and the water guiding cone is fixedly installed at the end of the runner hub by a hexagon socket head cap screw.

In the above solution, the inlet section and the cylindrical outer cylinder, the cylindrical outer cylinder and the elbow section are fixedly connected by bolts, and the inlet section and the cylindrical outer cylinder, the cylindrical outer cylinder Positioning between the curved pipe section and the curved pipe section is carried out in a concave-convex fitting manner.

In the above solution, the inlet section, the cylindrical outer cylinder and the elbow section are all sealed by O-rings.

In the above solution, a guide vane body is installed on the pump shaft, the guide vane body is located on the pump shaft, a deep groove ball bearing is installed in the guide vane body, and the left and right ends of the deep groove ball bearing are respectively installed There are bearing left oil seal and bearing right oil seal, and guide vanes are installed outside the guide vane body.

In the above solution, the pump shaft is also provided with an angular contact ball bearing, a washer oil seal and a shaft coupling.

Beneficial effects of the utility model: (1) Compared with the traditional diagonal flow pump, the wall structure of the runner chamber of the utility model is different, and the runner chamber wall of the utility model has annular grooves distributed in the circumferential direction of the runner chamber of the diagonal flow pump. When the fluid flows into the annular groove, a backflow will be formed. When the backflow in the annular groove interacts with the tip leakage flow, it can not only weaken the intensity of the tip leakage flow at the inlet to a certain extent, but also reduce its influence on the internal flow of the impeller. Improve the stability of the mixed flow pump. At the same time, it can also weaken the peripheral velocity of the tip leakage flow at the impeller inlet, thereby reducing the component of the peripheral velocity of the tip leakage flow to the incoming flow at the adjacent blade inlet, thereby reducing the angle of attack, effectively suppressing the occurrence of stall, and improving the performance of the diagonal flow pump. Stability, inhibit the appearance of "hump" phenomenon. (2) The annular groove can also effectively reduce the reverse pressure gradient at the impeller inlet under the condition of small flow rate, effectively suppress the generation of backflow, and reduce the flow loss.

Description of drawings

Fig. 1 is the assembly diagram of the utility model inclined flow pump.

Fig. 2 is a left side view of the section taken along the line A in Fig. 1 .

Fig. 3 is a partially enlarged view of B in Fig. 1 .

Figure 4 is the external characteristic curve of the oblique flow pump without slot and with annular slot.

In the figure: 1. Inlet section, 2. Hexagon socket head screw, 3. Water guide cone, 4. Blade, 5. Cylindrical head screw, 6. Bolt, 7. Guide vane, 8. Cylindrical outer cylinder, 9. Bend Pipe section, 10. Mechanical seal, 11. Angular contact ball bearing, 12. Gasket oil seal, 13. Coupling, 14. Annular groove, 15. Impeller inlet side, 16. Runner chamber wall, 17. Runner hub, 18. Guide vane body, 19. Bearing left oil seal, 20. Hexagon socket flat head screw, 21. Deep groove ball bearing, 22. Bearing right oil seal, 23. O-ring, 24. Pump shaft, 25. Inlet chamber wall.

detailed description

The utility model will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

It can be seen from Figure 1, Figure 2 and Figure 3 that the inclined flow pump is composed of an inlet section 1, a hexagon socket head screw 2, a water guide cone 3, a blade 4, a cylindrical head screw 5, a bolt 6, a guide vane 7, a cylinder Outer cylinder 8, elbow section 9, mechanical seal 10, angular contact ball bearing 11, gasket oil seal 12, coupling 13, annular groove 14, runner hub 17, guide vane body 18, bearing left oil seal 19, inner hexagon flat Round head screw 20, deep groove ball bearing 21, bearing right oil seal 22; O-shaped sealing ring 23, pump shaft 24. The inlet section 1 is connected and fixed with the cylindrical outer cylinder 8 through the bolt 6, and the inlet section 1 and the cylindrical outer cylinder 8 are positioned and ensured concentricity through concave-convex fitting; the cylindrical outer cylinder 8 and the elbow section 9 are also passed through by the bolt 6 The flanges are connected and fixed. In order to ensure the convenience of installation and the accuracy of the concentricity, the flange of the cylindrical outer cylinder and the flange of the elbow section are also embedded in a concave-convex way; the inner cavity wall of the inlet section 1 is composed of the inlet chamber wall 25 and the runner chamber wall. 16 consists of two parts, the inlet chamber wall 25 is a conical surface, the runner chamber wall 16 is an arc surface, and the runner chamber wall 16 is tangent to the inner wall of the cylindrical outer cylinder 8; the blade 4 is located In the runner chamber of the inlet section 1 , the impeller inlet edge 15 of the blade 4 just faces the junction of the inlet chamber wall 25 and the runner chamber wall 16 . An annular groove 14 with a J-shaped longitudinal section is formed at the junction of the inlet chamber wall 25 and the runner chamber wall 16 . The inlet section 1, the cylindrical outer cylinder 8 and the elbow section 10 are all sealed by the O-ring 22; the water guide cone 3 is fixed on the runner hub 17 with the hexagon socket head screw 2; the water guide cone not only The incoming flow acts as a flow guide, and can also determine the axial position of the runner hub 17 on the pump shaft 24; the blade 4 is fixed on the runner hub 17 by a cylindrical head screw 5; a deep groove is installed in the guide vane body 18 The ball bearing 21 realizes the connection between the stationary part and the rotating part through the deep groove bearing; the left oil seal 19 of the bearing and the right oil seal 22 of the bearing are respectively installed at the left and right ends of the deep groove ball bearing 21 to prevent the liquid from passing through the pump shaft 24 and the guide vane body 18 The gap between them enters the deep groove ball bearing 21 to cause bearing corrosion, and also has the effect of preventing impurities; the pump shaft 24 is also provided with an angular contact ball bearing 11, a washer oil seal 12 and a coupling 13. The coupling 13 connects the pump shaft 25 and the motor shaft.

As shown in Figure 4, the external characteristic curves of the oblique flow pump of the utility model without slots and with annular grooves obtained by using CFD simulation software, the specific speed of the oblique flow pump of the utility model is 829r/min, the diameter of the inlet section is 200mm, and the impeller The inlet diameter is 90.43mm, the impeller outlet diameter is 107.88mm, the number of impeller blades is 3 pieces, the number of guide vane blades is 5 pieces, the diameter of the outlet section is 250mm, the speed is 1450r/min, the depth of the groove is h=1mm, and the length of the groove is l=26mm. It can be seen from the figure that slotting has little effect on the performance of the diagonal flow pump under the condition of large flow rate, but as the flow rate decreases, the head difference between the head with annular groove and the head without slotting gradually increases, indicating that small Under flow conditions, the annular groove has a significant effect on reducing the leakage flow intensity at the tip of the inclined flow pump, thereby greatly improving the stability of the internal fluid flow of the inclined flow pump.

Claims (9)

1. diagonal pumps, including pump shaft (24), inducer (1), cylinder urceolus (8) and bend loss (9), described pump shaft (24) passes described cylinder urceolus (8) and described bend loss (9), blade (4) is installed on described pump shaft (24), it is characterized in that, the inner chamber wall of described inducer (1) is made up of upstream chamber wall (25) and runner envelope wall (16) two parts, described upstream chamber wall (25) is in the conical surface, described runner envelope wall (16) is in cambered surface, described runner envelope wall (16) is tangent with the internal face of described cylinder urceolus (8)；Described blade (4) is positioned at the runner envelope of described inducer (1), and described upstream chamber wall (25) and runner envelope wall (16) intersection have cannelure (14).

A kind of diagonal pumps the most according to claim 1, it is characterised in that the impeller inlet limit (15) of described blade (4) is just to described upstream chamber wall (25) and runner envelope wall (16) intersection.

A kind of diagonal pumps the most according to claim 1 and 2, it is characterised in that the longitudinal section of described cannelure (14) is J-shaped shape.

A kind of diagonal pumps the most according to claim 1 and 2, it is characterised in that being provided with runner boss (17) on described pump shaft (24), described blade (4) is fixed on described runner boss (17) by fillister head screw (5).

A kind of diagonal pumps the most according to claim 4, it is characterised in that being additionally provided with water guide cone (3) on described runner boss (17), described water guide cone (3) is fixedly mounted on described runner boss (17) end by hexagon socket cap head screw (2).

A kind of diagonal pumps the most according to claim 1 and 2, it is characterized in that, described inducer (1) and described cylinder urceolus (8), described cylinder urceolus (8) and described bend loss (9) all connect by bolt (6) is fixing, between described inducer (1) and described cylinder urceolus (8), between described cylinder urceolus (8) and described bend loss (9) all by concavo-convex chimeric by the way of position.

A kind of diagonal pumps the most according to claim 6, it is characterised in that described inducer (1), described cylinder urceolus (8) and described bend loss (9) are all to be sealed by O RunddichtringO (23).

A kind of diagonal pumps the most according to claim 4, it is characterized in that, diffuser (18) it is also equipped with on described pump shaft (24), described diffuser (18) is positioned on pump shaft (24), one deep groove ball bearing (21) is installed in described diffuser (18), be respectively provided with the left oil sealing of bearing (19) and the right oil sealing of bearing (22) at deep groove ball bearing (21) two ends, left and right, described diffuser (18) outside is provided with stator (7).

A kind of diagonal pumps the most according to claim 4, it is characterised in that be additionally provided with angular contact ball bearing (11), packing ring oil sealing (12) and shaft coupling (13) on described pump shaft (24).