A high-pressure centrifugal pump

Abstract

The present invention provides a high-pressure centrifugal pump, belonging to the technical field of pumps. It solves the technical problems such as the easy damage of the mechanical seal in the existing high-pressure centrifugal pump. This high-pressure centrifugal pump includes a pump body, a bracket and a pump shaft. A mechanical seal is arranged on the pump shaft. One end of the pump shaft is fixedly connected to an impeller. A shaft sleeve is fixedly connected to the pump shaft in a sealed manner. A pump cover is sleeved outside the shaft sleeve with a clearance. The pump cover includes a first seal mounting portion, a second seal mounting portion and a mounting connection portion. There is a mounting through hole in the middle of the first seal mounting portion, and the mounting through hole is in clearance fit with the outer circumference of the shaft sleeve. A first seal is arranged between the outer circumference of the second seal mounting portion and the inner circumference of the pump body. An elastic member is arranged between the second seal mounting portion and the bracket. There is an axial clearance between one end of the mounting connection portion close to the impeller and the impeller. One end of the mechanical seal is fixedly connected to the first seal mounting portion, and the other end is fixedly connected to the shaft sleeve. The present invention can reduce the wear of the mechanical seal and extend its service life.

Description

Technical Field

[0001] The present invention belongs to the technical field of pumps, and particularly refers to a high-pressure centrifugal pump. Background Art

[0002] A high-pressure centrifugal pump is a mechanical device that uses the principle of centrifugal force to transport liquids, and is mainly used in occasions that require high pressure, such as high-rise water supply, fire protection systems, etc. The centrifugal pump uses mechanical seals to seal the rotating shaft and the stationary pump body. The sealing function of the mechanical seal is completed by two main sealing rings with planes. One of the dynamic sealing rings rotates together with the shaft, and the other static sealing ring is fixed on the housing. The dynamic sealing ring and the static sealing ring are subjected to axial forces, so that the sealing surfaces of the dynamic sealing ring and the static sealing ring always maintain frictional contact. This stable contact can prevent leakage from the sealing surface or minimize the leakage amount. However, the mechanical seal is installed in the high-pressure centrifugal pump. When the high-pressure centrifugal pump sucks a large flow of liquid into the impeller, the impeller will be subjected to an axial thrust, and then the axial thrust will be transmitted to the pump shaft, causing the pump shaft to vibrate axially, resulting in fluctuations in the contact pressure of the sealing surface, aggravating wear or instantaneous leakage, resulting in a sudden drop in the pressure inside the high-pressure centrifugal pump, and even unable to maintain the working pressure. How to better protect the mechanical seal to make its sealing effect better and ensure the stability of the working pressure inside the high-pressure centrifugal pump. Summary of the Invention

[0003] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a high-pressure centrifugal pump.

[0004] The purpose of the present invention can be achieved by the following technical solutions: A high-pressure centrifugal pump includes a pump body with a pump chamber and a bracket fixedly connected to the pump body. A pump shaft is rotatably installed in the pump body and the bracket. A mechanical seal is arranged on the pump shaft. One end of the pump shaft is fixedly connected to an impeller, and the impeller is located in the pump chamber. A shaft sleeve is fixedly connected to the pump shaft in a sealed manner. A pump cover is sleeved outside the shaft sleeve with a gap. The pump cover includes a first seal installation part, a second seal installation part, and an installation connection part that smoothly connects the first seal installation part and the second seal installation part. There is an installation through hole in the middle of the first seal installation part, and the installation through hole is in clearance fit with the outer circumference of the shaft sleeve. A first seal is arranged between the outer circumference of the second seal installation part and the inner circumference of the pump body. An elastic member is arranged between the second seal installation part and the bracket. There is an axial gap between one end of the installation connection part close to the impeller and the impeller. One end of the mechanical seal is fixedly connected to the first seal installation part, and the other end is fixedly connected to the shaft sleeve.

[0005] The pump cover is slidably connected to the pump body. The first seal radially supports and seals the pump cover. The pump cover is fixed at the end of the mechanical seal, and the mechanical seal axially supports and seals the pump cover. The elastic member assists the mechanical seal to adapt to the axial displacement caused by thermal expansion or pressure fluctuations, reduces the wear of the mechanical seal, and extends the service life.

[0006] Furthermore, the impeller protrudes towards the pump cover with a flow-limiting portion, and the installation connection portion has a flow-limiting hole. The flow-limiting portion is embedded in the flow-limiting hole and maintains an axial gap with the pump cover. The optimized flow channel structure of the flow-limiting portion and the flow-limiting hole controls the fluid pressure through its gap, reduces the back pressure of the impeller, and improves the pump efficiency of the high-pressure centrifugal pump.

[0007] Furthermore, the pump shaft includes a first fixing portion, a second fixing portion, and a third fixing portion with diameters increasing successively. The first fixing portion passes through and fixes the inducer. One end of the inducer abuts against the impeller. The impeller is fixed to the second fixing portion by a long key. The shaft sleeve protrudes towards the pump shaft with a positioning protrusion. The end of the impeller away from the inducer abuts against the positioning protrusion, and the other end face of the positioning protrusion abuts against the shoulders of the second fixing portion and the third fixing portion. Integrating the rotation of the inducer, the impeller, and the shaft sleeve reduces the torque loss of the pump shaft caused by inconsistent rotation among the three, and improves the pump efficiency of the high-pressure centrifugal pump.

[0008] Furthermore, the shaft sleeve and the impeller respectively have axially straight long slots one and two, and the outer periphery of the second fixing portion is provided with a long slot three. The long key is located in the long slots one, two, and three.

[0009] Furthermore, a second seal is fixedly arranged between the shaft sleeve and the third fixing portion.

[0010] Furthermore, the pump body is provided with a first mounting hole, a second mounting hole, and a third mounting hole that are directly connected to each other and have successively increasing inner diameters. The first mounting hole is directly connected to the pump chamber. The second seal mounting portion is provided with a seal groove relative to the first mounting hole, and the first seal is located in the seal groove.

[0011] Furthermore, a positioning ring protrudes from the position of the second seal mounting portion relative to the third mounting hole. The outer diameter of the positioning ring is larger than the inner diameter of the second mounting hole and smaller than the inner diameter of the third mounting hole. An elastic member is arranged between the positioning ring and the bracket.

[0012] Furthermore, the mechanical seal includes a static seal portion and a dynamic seal portion. The static seal portion and the dynamic seal portion are in planar seal contact. One end of the static seal portion away from the dynamic seal portion is fixedly and sealingly connected to the first seal mounting portion, and the dynamic seal portion is fixedly and sealingly connected to the shaft sleeve.

[0013] Further, the static seal part includes a static pressure seat. A seal member III is fixedly arranged between one end of the static pressure seat close to the pump cover and the pump cover. One end of the static pressure seat away from the pump cover is hermetically and fixedly connected to a static seal ring. The dynamic seal part includes a dynamic pressure seat. A dynamic buffer ring and a dynamic seal ring are fixedly arranged circumferentially on the side wall of the dynamic pressure seat. A sealing ring is arranged between the dynamic seal ring and the shaft sleeve. Circumferentially distributed first reset members are arranged between the dynamic seal ring and the dynamic buffer ring. Circumferentially distributed second reset members are arranged between the dynamic buffer ring and the bottom wall of the dynamic pressure seat. The first reset members and the second reset members are arranged staggeredly. The staggered arrangement of the first reset members and the second reset members allows for more first reset members and second reset members to be arranged, enabling the uniform distribution of pressure in the dynamic seal part, avoiding eccentric wear between the static seal ring and the dynamic seal ring, and improving the sealing stability under high pressure.

[0014] Further, at least two first blind holes and second blind holes are arranged on the dynamic buffer ring. The openings of the first blind holes face the dynamic seal ring, and the openings of the second blind holes face the bottom wall of the dynamic pressure seat. The number of the first blind holes and the second blind holes is equal and they are arranged at intervals. The first reset members are located in the first blind holes, and the second reset members are located in the second blind holes.

[0015] Compared with the prior art, the technical effects of the present invention are as follows: First, the pump cover and the pump body are slidably connected. The seal member I radially supports and seals the pump cover. The pump cover is fixed at the end of the mechanical seal, and the mechanical seal axially supports and seals the pump cover. The elastic member assists the mechanical seal to adapt to the axial displacement caused by thermal expansion or pressure fluctuation, reducing the wear of the mechanical seal and extending its service life. Second, the shaft sleeve forms a rigid contact with the pump shaft shoulder and the impeller through the positioning convex block, directly transmitting the axial thrust generated by the impeller to the pump shaft bearing system, avoiding the mechanical seal from bearing the axial load, better protecting the mechanical seal and making its sealing effect better, and ensuring the stability of the working pressure inside the high-pressure centrifugal pump. Second, the inducer, the impeller, and the shaft sleeve are integrally rotated, reducing the loss of torque on the pump shaft caused by the inconsistent rotation among the three, and improving the pump efficiency of the high-pressure centrifugal pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a cross-sectional view of the present invention.

[0017] Figure 2 is an enlarged view of part A of the present invention.

[0018] Figure 3 is a cross-sectional view of the pump cover, the mechanical seal, and the shaft sleeve of the present invention.

[0019] Figure 4 is an exploded view of the pump cover, the shaft sleeve, the impeller, and the mechanical seal of the present invention.

[0020] Figure 5 is a three-dimensional view of the dynamic buffer ring, the first reset member, and the second reset member of the present invention Figure 1 .

[0021] Figure 6 is a three-dimensional view of the dynamic buffer ring, the first reset member, and the second reset member of the present invention Figure 2 .

[0022] Figure number markings: 1, pump body; 101, pump chamber; 102, first mounting hole; 103, second mounting hole; 104, third mounting hole; 2, bracket; 3, pump shaft; 301, first fixing portion; 302, second fixing portion; 303, third fixing portion; 304, long slot three; 4, impeller; 401, current limiting portion; 402, long slot two; 5, shaft sleeve; 501, positioning convex block; 502, long slot one; 6, pump cover; 601, first sealing mounting portion; 602, second sealing mounting portion; 603, mounting connection portion; 604, mounting through hole; 605, current limiting hole; 606, sealing groove; 607, positioning ring; 7, first seal; 8, elastic member; 9, inducer; 10, long key; 11, second seal; 12, static seal portion; 1201, static pressure seat; 1202, third seal; 1203, static seal ring; 13, dynamic seal portion; 1301, dynamic pressure seat; 1302, dynamic buffer ring; 1303, dynamic seal ring; 1304, sealing ring; 1305, first reset member; 1306, second reset member; 1307, first blind hole; 1308, second blind hole. Detailed implementation manners

[0023] The following are specific embodiments of the present invention and in combination with the accompanying drawings, the technical solutions of the present invention are further described, but the present invention is not limited to these embodiments.

[0024] It should be noted that the descriptions of the present invention in terms of directions such as "upper", "lower", "left", "right", "top", "bottom", etc. are all defined based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device must be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention.

[0025] According to Figures 1 to 6As shown in the figure, a high-pressure centrifugal pump includes a pump body 1 having a pump chamber 101 and a bracket 2 fixedly connected to the pump body 1. A pump shaft 3 is rotatably installed in the pump body 1 and the bracket 2. A mechanical seal is provided on the pump shaft 3. One end of the pump shaft 3 is fixedly connected to an impeller 4. The impeller 4 is located in the pump chamber 101. The other end of the pump shaft 3 is connected to a driving motor. A shaft sleeve 5 is fixedly connected to the pump shaft 3 in a sealed manner. A pump cover 6 is sleeved outside the shaft sleeve 5 with a gap. The pump cover 6 is connected in a non-rigid manner. The pump cover 6 includes a first seal mounting portion 601, a second seal mounting portion 602, and a mounting connection portion 603 that smoothly connects the first seal mounting portion 601 and the second seal mounting portion 602. There is a mounting through hole 604 in the middle of the first seal mounting portion 601. The mounting through hole 604 is in clearance fit with the outer circumference of the shaft sleeve 5. A first seal 7 is provided between the outer circumference of the second seal mounting portion 602 and the inner circumference of the pump body 1. An elastic member 8 is provided between the second seal mounting portion 602 and the bracket 2. There is an axial gap between one end of the mounting connection portion 603 close to the impeller 4 and the impeller 4. One end of the mechanical seal is fixedly connected to the first seal mounting portion 601 and the other end is fixedly connected to the shaft sleeve 5.

[0026] The impeller 4 protrudes towards the pump cover 6 with a flow limiting portion 401. The installation connection portion 603 has a flow limiting hole 605. The flow limiting portion 401 is embedded in the flow limiting hole 605 and maintains an axial gap with the pump cover 6. The optimized flow channel structure of the flow limiting portion 401 and the flow limiting hole 605 controls the fluid pressure through its gap, reduces the back pressure of the impeller 4, and improves the pump efficiency of the high-pressure centrifugal pump. The mechanical seal includes a static seal portion 12 and a dynamic seal portion 13. The static seal portion 12 and the dynamic seal portion 13 are in plane sealing contact. One end of the static seal portion 12 away from the dynamic seal portion 13 is fixedly and sealingly connected to the first seal installation portion 601, and the dynamic seal portion 13 is fixedly and sealingly connected to the shaft sleeve 5. The static seal portion 12 includes a static pressure seat 1201. A seal member three 1202 is fixedly arranged between one end of the static pressure seat 1201 close to the pump cover 6 and the pump cover 6. One end of the static pressure seat 1201 away from the pump cover 6 is fixedly and sealingly connected to the static seal ring 1203. The dynamic seal portion 13 includes a dynamic pressure seat 1301. A dynamic buffer ring 1302 and a dynamic seal ring 1303 are circumferentially fixed on the side wall of the dynamic pressure seat 1301. A sealing ring 1304 is arranged between the dynamic seal ring 1303 and the shaft sleeve 5. A circumferentially evenly distributed first reset member 1305 is arranged between the dynamic seal ring 1303 and the dynamic buffer ring 1302. A circumferentially evenly distributed second reset member 1306 is arranged between the dynamic buffer ring 1302 and the bottom wall of the dynamic pressure seat 1301. The first reset member 1305 and the second reset member 1306 are arranged staggeredly. The staggered arrangement of the first reset member 1305 and the second reset member 1306 allows for more first reset members 1305 and second reset members 1306 to be arranged, enabling the dynamic seal portion 13 to distribute pressure evenly, avoiding eccentric wear of the static seal ring 1203 and the dynamic seal ring 1303, and improving the sealing stability under high pressure. At least two first blind holes 1307 and second blind holes 1308 are provided on the dynamic buffer ring 1302. The first blind holes 1307 open towards the dynamic seal ring 1303, and the second blind holes 1308 open towards the bottom wall of the dynamic pressure seat 1301. The number of the first blind holes 1307 and the second blind holes 1308 is equal and they are arranged at intervals. The first reset member 1305 is located in the first blind hole 1307, and the second reset member 1306 is located in the second blind hole 1308.

[0027] The pump body 1 is provided with a first installation hole 102, a second installation hole 103, and a third installation hole 104 that are directly connected to each other and have gradually increasing inner diameters. The first installation hole 102 is directly connected to the pump chamber 101. The second seal installation portion 602 is provided with a seal groove 606 relative to the first installation hole 102. The seal member one 7 is located in the seal groove 606. The second seal installation portion 602 protrudes with a positioning ring 607 relative to the position of the third installation hole 104. The outer diameter of the positioning ring 607 is larger than the inner diameter of the second installation hole 103 and smaller than the inner diameter of the third installation hole 104. An elastic member 8 is arranged between the positioning ring 607 and the bracket 2.

[0028] The pump cover 6 is slidably connected to the pump body 1. The first seal 7 radially supports and seals the pump cover 6. The pump cover 6 is fixed at the end of the mechanical seal, and the mechanical seal axially supports and seals the pump cover 6. The elastic member 8 assists the mechanical seal to adapt to the axial displacement caused by thermal expansion or pressure fluctuation, reduces the wear of the mechanical seal, and extends the service life.

[0029] The pump shaft 3 includes a first fixed portion 301, a second fixed portion 302, and a third fixed portion 303 with diameters increasing in sequence. The first fixed portion 301 passes through and fixes the inducer 9. One end of the inducer 9 abuts against the impeller 4. The impeller 4 is fixed to the second fixed portion 302 by a long key 10. The sleeve 5 protrudes towards the pump shaft 3 with a positioning protrusion 501. The end of the impeller 4 away from the inducer 9 abuts against the positioning protrusion 501, and the other end face of the positioning protrusion 501 abuts against the shoulder between the second fixed portion 302 and the third fixed portion 303. The sleeve 5 and the impeller 4 respectively have an axially through long slot one 502 and long slot two 402. A long slot three 304 is provided on the outer periphery of the second fixed portion 302. The long key 10 is located in the long slot one 502, long slot two 402, and long slot three 304. A second seal 11 is fixedly arranged between the sleeve 5 and the third fixed portion 303. The inducer 9, the impeller 4, and the sleeve 5 are integrally rotated, reducing the loss of torque on the pump shaft 3 caused by inconsistent rotation among the three, and improving the pump efficiency of the high-pressure centrifugal pump.

[0030] The above embodiments are only preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope defined by the claims of the present invention.

Claims

1. A high-pressure centrifugal pump, comprising a pump body (1) having a pump chamber (101) and a bracket (2) fixedly connected to the pump body (1), a pump shaft (3) rotatably mounted in the pump body (1) and the bracket (2), a mechanical seal being arranged on the pump shaft (3), one end of the pump shaft (3) being fixedly connected to an impeller (4), the impeller (4) being located in the pump chamber (101), characterized in that: A shaft sleeve (5) is sealed and fixedly connected to the pump shaft (3); a pump cover (6) is sleeved on the outer clearance of the shaft sleeve (5); the pump cover (6) comprises a first sealing mounting portion (601), a second sealing mounting portion (602), and a mounting connection portion (603) for smoothly connecting the first sealing mounting portion (601) and the second sealing mounting portion (602); a mounting through hole (604) is provided in the middle of the first sealing mounting portion (601); a clearance between the mounting through hole (604) and the outer periphery of the shaft sleeve (5) is A sealing member (7) is provided between the outer periphery of the second sealing mounting portion (602) and the inner periphery of the pump body (1), an elastic member (8) is provided between the second sealing mounting portion (602) and the bracket (2), an axial gap is provided between the end of the mounting connection portion (603) close to the impeller (4) and the impeller (4), one end of the mechanical seal is fixedly connected to the first sealing mounting portion (601), and the other end is fixedly connected to the shaft sleeve (5), and the pump cover (6) is slidably connected to the pump body (1).

2. A high-pressure centrifugal pump according to claim 1, characterized in that: The impeller (4) has a flow limiting portion (401) protruding in the direction of the pump cover (6), the mounting connection portion (603) has a flow limiting hole (605), and the flow limiting portion (401) is embedded in the flow limiting hole (605) and maintains an axial gap with the pump cover (6).

3. A high-pressure centrifugal pump according to claim 1 or 2, characterized in that: The pump shaft (3) comprises a first fixing portion (301), a second fixing portion (302) and a third fixing portion (303) of which the diameters increase successively. The first fixing portion (301) is provided with a fixed inducer (9), one end of the inducer (9) abuts against the impeller (4), the impeller (4) is fixed to the second fixing portion (302) by a long key (10), the shaft sleeve (5) protrudes with a positioning protrusion (501) toward the pump shaft (3), one end of the impeller (4) away from the inducer (9) abuts against the positioning protrusion (501), and the other end face of the positioning protrusion (501) abuts against the shaft shoulders of the second fixing portion (302) and the third fixing portion (303).

4. A high-pressure centrifugal pump according to claim 3, characterized in that: The shaft sleeve (5) and the impeller (4) respectively have an axially straight long groove one (502) and a long groove two (402); the outer periphery of the second fixing portion (302) is provided with a long groove three (304); and the long key (10) is located in the long groove one (502), the long groove two (402) and the long groove three (304).

5. A high-pressure centrifugal pump according to claim 4, characterized in that: A second sealing member (11) is fixedly arranged between the shaft sleeve (5) and the third fixing portion (303).

6. A high-pressure centrifugal pump according to claim 1, characterized in that: The pump body (1) is provided with a first mounting hole (102), a second mounting hole (103) and a third mounting hole (104) which are directly connected to each other and have inner diameters increasing successively. The first mounting hole (102) is directly connected to the pump chamber (101). The second sealing mounting portion (602) is provided with a sealing groove (606) relative to the first mounting hole (102), and the sealing member 1 (7) is located in the sealing groove (606).

7. A high-pressure centrifugal pump according to claim 6, characterized in that: A positioning ring (607) protrudes from the second sealing mounting portion (602) at a position relative to the third mounting hole (104); the outer diameter of the positioning ring (607) is larger than the inner diameter of the second mounting hole (103) and smaller than the inner diameter of the third mounting hole (104); and an elastic member (8) is provided between the positioning ring (607) and the bracket (2).

8. A high-pressure centrifugal pump according to claim 1, characterized in that: The mechanical seal comprises a static sealing part (12) and a dynamic sealing part (13), wherein the static sealing part (12) and the dynamic sealing part (13) are planarly sealed against each other, an end of the static sealing part (12) away from the dynamic sealing part (13) is sealed and fixedly connected to a first sealing mounting part (601), and the dynamic sealing part (13) is sealed and fixedly connected to a shaft sleeve (5).

9. A high-pressure centrifugal pump according to claim 8, characterized in that: The static sealing part (12) comprises a static pressure seat (1201), a sealing member 3 (1202) is fixedly arranged between the end of the static pressure seat (1201) close to the pump cover (6) and the pump cover (6), and a static sealing ring (1203) is sealed and fixedly connected to the end of the static pressure seat (1201) away from the pump cover (6). The dynamic sealing part (13) comprises a dynamic pressure seat (1301), and a dynamic buffer ring (1302) and a dynamic sealing ring (1303) are fixedly arranged on the side wall of the dynamic pressure seat (1301) in the circumferential direction. 303), a sealing ring (1304) is arranged between the dynamic sealing ring (1303) and the shaft sleeve (5), a circumferentially uniformly distributed first reset member (1305) is arranged between the dynamic sealing ring (1303) and the dynamic buffer ring (1302), a circumferentially uniformly distributed second reset member (1306) is arranged between the dynamic buffer ring (1302) and the bottom wall of the dynamic pressure seat (1301), and the first reset member (1305) and the second reset member (1306) are staggered.

10. A high-pressure centrifugal pump according to claim 9, characterized in that: At least two first blind holes (1307) and second blind holes (1308) are provided on the dynamic buffer ring (1302); the first blind hole (1307) opens toward the dynamic sealing ring (1303); the second blind hole (1308) opens toward the bottom wall of the dynamic pressure seat (1301); the first blind holes (1307) and the second blind holes (1308) are equal in number and are spaced apart from each other; the first reset member (1305) is located in the first blind hole (1307); and the second reset member (1306) is located in the second blind hole (1308).

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