Fixing structure for impeller and inducer of high-pressure pump

Abstract

The utility model provides a fixing structure for an impeller and an inducer of a high-pressure pump, and belongs to the technical field of pumps. The high-pressure pump solves the technical problems that an inducer and an impeller in an existing high-pressure pump are poorly centered, and extra vibration and abrasion are possibly caused. The fixing structure for the impeller and the inducer of the high-pressure pump comprises a pump shell, a pump shaft, the impeller and the inducer, the pump shaft comprises a first fixing section, a second fixing section and a third fixing section, the inner diameters of the first fixing section, the second fixing section and the third fixing section are sequentially increased, the third fixing section is fixedly sleeved with a shaft sleeve in a sealed mode, the second fixing section is fixedly sleeved with the impeller, and the first fixing section is fixedly sleeved with the inducer. A fixing part is fixed to the end, away from the impeller, of the first fixing section in a threaded mode, one end of the shaft sleeve abuts against one end of the impeller, the other end of the impeller abuts against the inducer, the shaft sleeve and the impeller are provided with a first straight-through fixing groove and a second straight-through fixing groove respectively, a third fixing groove is formed in the second fixing section, and first fixing keys are arranged in the first fixing groove, the second fixing groove and the third fixing groove. Vibration and abrasion of the pump shaft are reduced, and the working efficiency of the pump is improved.

Description

Technical Field

[0001] This utility model belongs to the field of pump technology, specifically referring to a fixing structure for the impeller and inducer of a high-pressure pump. Background Technology

[0002] High-pressure pumps are used in special firefighting environments and may not be used for extended periods, but must be started immediately when needed. Therefore, cavitation within the pump is often a significant problem during startup. Cavitation damages the flow path, leading to a decrease in head and efficiency. Inducers are generally used for pressurization, increasing the inlet pressure and preventing cavitation. With a small angle of attack and a thin inlet edge, the inducer causes minimal disturbance to the flow, minimizing cavitation formation. Its function is to gradually increase the pump pressure to a certain level, providing the high-pressure pump with the required head and efficiency.

[0003] In existing technologies, such as the centrifugal pump inducer drive device disclosed in CN102042262A, the rear end of the inducer hub has a threaded hole, and the front end of the drive shaft has an external thread. The external thread mates with the threaded hole to fasten the inducer to the drive shaft. This installation results in poor alignment between the inducer and impeller, potentially leading to additional vibration and wear, affecting the pump's stability and lifespan. The challenge lies in achieving better coaxiality between the impeller and inducer, ensuring axial and radial synchronization during rotation, and improving pump efficiency. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a fixing structure for the impeller and inducer of a high-pressure pump.

[0005] The objective of this utility model can be achieved through the following technical solution: A fixing structure for the impeller and inducer of a high-pressure pump, comprising a pump casing, a pump shaft, an impeller, and an inducer. The pump shaft includes a first fixing section, a second fixing section, and a third fixing section with sequentially increasing inner diameters. A bushing is externally sealed and fixedly fitted on the third fixing section. An impeller is fixedly fitted on the second fixing section. An inducer is fixedly fitted on the first fixing section. A fixing member is threadedly fixed to the end of the first fixing section away from the impeller. One end of the bushing abuts against one end of the impeller, and the other end of the impeller abuts against the inducer. The bushing and the impeller each have a straight-through fixing groove one and a fixing groove two. The second fixing section has a fixing groove three. A fixing key one is provided in the fixing groove one, fixing groove two, and fixing groove three. The first fixing section has a fixing groove four. The inducer has a fixing groove five. A fixing key two is provided in the fixing groove four and fixing groove five. The fixing key is embedded in fixing slots one, two, and three to ensure that the impeller, bushing, and pump shaft are circumferentially fixed, preventing offset during rotation and maintaining radial alignment. The bushing and impeller, and the impeller and inducer abut against each other through end faces to form axial positioning. The threaded fastener at the end of the first fixing section applies axial preload to press the inducer, impeller, and bushing, eliminating axial clearance and ensuring axial alignment. This allows the bushing, impeller, and inducer to maintain better coaxiality, ensuring axial and radial synchronization when the impeller and inducer rotate, reducing pump shaft vibration and wear, and improving pump efficiency.

[0006] Furthermore, the helix angle of the inducer is greater than that of the impeller. The helix angle of the inducer is 15° larger than that of the impeller. The combination of this inducer and impeller enables dual-stage synergy between inducer pre-pressurization and impeller main pressurization, ensuring a high head output of 160 meters at a speed of 4000 rpm with a NPSHr (Net Positive Suction Head) of less than or equal to 3.5 meters.

[0007] Furthermore, the inducer wheel includes a conical hub and a spiral inducer plate, the width of which gradually widens and then narrows again along the conical hub.

[0008] Furthermore, a pump cover and a mechanical seal are provided outside the bushing. One end of the mechanical seal is fixedly sealed to the pump cover, and the other end of the mechanical seal is fixedly sealed to the bushing.

[0009] Furthermore, the pump cover includes a conical sealing part and a cylindrical sealing part, the conical sealing part being fixed to the mechanical seal, and the cylindrical sealing part being sealed and fixed to the pump casing.

[0010] Furthermore, the cylindrical sealing part has an inwardly recessed sealing groove and an outwardly protruding positioning ring. The pump casing has a first mounting hole, a second mounting hole, and a third mounting hole that are interconnected and increase in diameter sequentially. A sealing element is provided between the sealing groove and the first mounting hole. The positioning ring is embedded in the third mounting hole. A bracket is fixedly connected to the pump casing by fasteners. The bracket has a fixing ring protruding towards the pump cover, and the fixing ring abuts against the positioning ring. The cylindrical sealing part of the pump cover cooperates with the stepped mounting holes of the pump casing through the sealing groove and the positioning ring to ensure the coaxiality of the pump cover and the pump casing.

[0011] Compared with the prior art, the technical effects of this utility model are as follows: 1. The fixing key is embedded in fixing grooves one, two, and three to ensure that the impeller, bushing, and pump shaft are circumferentially fixed, preventing offset during rotation and maintaining radial alignment. The bushing and impeller, and the impeller and inducer abut against each other through end face abutment, forming axial positioning. The threaded fastener at the end of the first fixing section applies axial preload, pressing the inducer, impeller, and bushing to eliminate axial clearance and ensure axial alignment. This allows the bushing, impeller, and inducer to maintain better coaxiality, ensuring axial and radial synchronization when the impeller and inducer rotate, reducing pump shaft vibration and wear, and improving pump efficiency. 2. The helix angle of the inducer is greater than that of the impeller, optimizing fluid guidance, reducing radial force caused by asymmetric flow, and indirectly improving alignment stability. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view of the present invention.

[0013] Figure 2 This is a partial sectional view of the present invention.

[0014] Figure 3 This is a three-dimensional view of the pump shaft of this utility model.

[0015] Drawing number markings: 1. Pump casing; 2. Pump shaft; 201. First fixed section; 202. Second fixed section; 203. Third fixed section; 204. Fixed groove three; 205. Fixed groove four; 3. Impeller; 301. Fixed groove two; 4. Inducer wheel; 401. Fixed groove five; 402. Conical hub; 403. Spiral inducer plate; 5. Shaft sleeve; 501. Fixed groove one; 6. Fixing component; 7. Fixed key one; 8. Fixed key two; 9. Mechanical seal; 10. Pump cover; 1001. Conical sealing part; 1002. Cylindrical sealing part; 1003. Sealing groove; 1004. Positioning ring; 11. Bracket; 1101. Fixing ring; 12. Sealing component. Detailed Implementation

[0016] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0017] It should be noted that the descriptions of "up", "down", "left", "right", "top", "bottom", etc. in this utility model are defined 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 are not intended to indicate or imply that the device must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0018] according to Figures 1 to 3 As shown, a fixing structure for an impeller 3 and an inducer 4 of a high-pressure pump includes a pump casing 1, a pump shaft 2, an impeller 3, and an inducer 4. The pump shaft 2 includes a first fixing section 201, a second fixing section 202, a third fixing section 203, a fourth fixing section, and a bearing fixing section, with the inner diameters increasing sequentially. The bearing fixing section has two ends and is located at both ends of the fourth fixing section. The third fixing section 203 is externally sealed and fixedly fitted with a shaft sleeve 5. The second fixing section 202 is fixedly fitted with the impeller 3. One of the bearing fixing sections connects the third fixing section 203 and the fourth fixing section. The two bearing fixing sections are used to fix the bearing, which is fixed on a bracket 11. The first fixing section 201 is fixedly fitted with the inducer 4. A fixing member 6 is threadedly fixed to the end of the first fixing section 201 away from the impeller 3. A gasket is provided between the fixing member 6 and the inducer 4. One end of the bushing 5 abuts against one end of the impeller 3, and the other end of the impeller 3 abuts against the inducer 4. The bushing 5 and the impeller 3 each have a straight-through fixing groove 501 and a fixing groove 301, respectively. The second fixing section 202 has a fixing groove 204. Fixing keys 7 are provided in fixing grooves 501, 301, and 204. The first fixing section 201 has a fixing groove 205, and the inducer 4 has a fixing groove 401. Fixing keys 8 are provided in fixing grooves 205 and 401. Fixing keys 8 and 7 are on the same side of the pump shaft 2. The fixing key 7 is embedded in fixing groove 501, fixing groove 301, and fixing groove 204 to ensure that the impeller 3, shaft sleeve 5, and pump shaft 2 are circumferentially fixed, preventing offset during rotation and maintaining radial alignment. The shaft sleeve 5 and impeller 3, and impeller 3 and inducer 4 abut against each other through their end faces to form axial positioning. The threaded fastener 6 at the end of the first fixing section 201 applies axial preload, pressing the inducer 4, impeller 3, and shaft sleeve 5 to eliminate axial clearance and ensure axial alignment. This ensures better coaxiality of the shaft sleeve 5, impeller 3, and inducer 4, ensuring axial and radial synchronization when the impeller 3 and inducer 4 rotate, reducing vibration and wear of the pump shaft 2, and improving pump efficiency. A pump cover 10 and a mechanical seal 9 are provided outside the shaft sleeve 5. One end of the mechanical seal 9 is fixedly sealed to the pump cover 10, and the other end of the mechanical seal 9 is fixedly sealed to the shaft sleeve 5.

[0019] The pump cover 10 includes a conical sealing part 1001 and a cylindrical sealing part 1002. The conical sealing part 1001 is fixed to the mechanical seal 9, and the cylindrical sealing part 1002 is sealed and fixed to the pump housing 1. The cylindrical sealing part 1002 has an inwardly recessed sealing groove 1003 and an outwardly protruding positioning ring 1004. The pump housing 1 has a first mounting hole, a second mounting hole, and a third mounting hole that are interconnected and have progressively larger diameters. A sealing element 12 is provided between the sealing groove 1003 and the first mounting hole. The positioning ring 1004 is embedded in the third mounting hole. A bracket 11 is fixedly connected to the pump housing 1 by fasteners. A fixing ring 1101 protrudes from the bracket 11 toward the pump cover 10 and abuts against the positioning ring 1004. The cylindrical sealing part 1002 of the pump cover 10 cooperates with the stepped mounting hole of the pump housing 1 through the sealing groove 1003 and the positioning ring 1004 to ensure the coaxiality of the pump cover 10 and the pump housing 1.

[0020] The helix angle of the inducer 4 is greater than that of the impeller 3. The helix angle of the inducer 4 is 15° larger than that of the impeller 3. The inducer 4 includes a conical hub 402 and a spiral guide vane 403. The width of the spiral guide vane 403 gradually widens and then narrows again along the conical hub 402. The cooperation between the inducer 4 and the impeller 3 enables a two-stage synergy between the pre-pressurization of the inducer 4 and the main pressurization of the impeller 3. At a speed of 4000 rpm, the NPSHr (Net Positive Suction Head) is less than or equal to 3.5 meters, ensuring a high head output of 160 meters.

[0021] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of protection of the present utility model. Therefore, all equivalent changes made to the structure, shape, and principle of the present utility model should be covered within the scope of protection defined by the claims of the present utility model.

Claims

1. A fixing structure for the impeller and inducer of a high-pressure pump, comprising a pump casing (1), a pump shaft (2), an impeller (3), and an inducer (4), characterized in that: The pump shaft (2) includes a first fixed section (201), a second fixed section (202), and a third fixed section (203) with progressively increasing inner diameters. The third fixed section (203) is externally sealed with a bushing (5). The second fixed section (202) is fitted with an impeller (3). The first fixed section (201) is fitted with an inducer wheel (4). A fixing member (6) is threaded onto the end of the first fixed section (201) away from the impeller (3). One end of the bushing (5) abuts against one end of the impeller (3), and the other end of the impeller (3) abuts against the inducer wheel (4). 4) Abutting, the bushing (5) and impeller (3) respectively have a straight fixed groove one (501) and a fixed groove two (301), the second fixed section (202) has a fixed groove three (204), a fixed key one (7) is provided in the fixed groove one (501), the fixed groove two (301) and the fixed groove three (204), the first fixed section (201) has a fixed groove four (205), the inducer (4) has a fixed groove five (401), a fixed key two (8) is provided in the fixed groove four (205) and the fixed groove five (401).

2. The fixing structure for the impeller and inducer of a high-pressure pump according to claim 1, characterized in that: The helix angle of the inducer (4) is greater than that of the impeller (3).

3. The fixing structure for the impeller and inducer of a high-pressure pump according to claim 2, characterized in that: The inducer wheel (4) includes a conical hub (402) and a spiral inducer plate (403), the width of which changes from narrow to wide and then back to narrow along the conical hub (402).

4. The fixing structure for the impeller and inducer of a high-pressure pump according to claim 1, 2, or 3, characterized in that: The bushing (5) is provided with a pump cover (10) and a mechanical seal (9). One end of the mechanical seal (9) is fixedly sealed to the pump cover (10), and the other end of the mechanical seal (9) is fixedly sealed to the bushing (5).

5. The fixing structure for the impeller and inducer of a high-pressure pump according to claim 4, characterized in that: The pump cover (10) includes a conical sealing part (1001) and a cylindrical sealing part (1002). The conical sealing part (1001) is fixed to the mechanical seal (9), and the cylindrical sealing part (1002) is sealed and fixed to the pump housing (1).

6. The fixing structure for the impeller and inducer of a high-pressure pump according to claim 5, characterized in that: The cylindrical sealing part (1002) has an inwardly recessed sealing groove (1003) and an outwardly protruding positioning ring (1004). The pump housing (1) has a first mounting hole, a second mounting hole and a third mounting hole that are interconnected and increase in diameter in sequence. A sealing element (12) is provided between the sealing groove (1003) and the first mounting hole. The positioning ring (1004) is embedded in the third mounting hole. A bracket (11) is fixedly connected to the pump housing (1) by fasteners. A fixing ring (1101) protrudes from the bracket (11) toward the pump cover (10). The fixing ring (1101) abuts against the positioning ring (1004).

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