High-pressure centrifugal pump

Abstract

The invention provides a high-pressure centrifugal pump, and belongs to the technical field of pumps. The technical problem that a mechanical seal in an existing high-pressure centrifugal pump is prone to damage is solved. The high-pressure centrifugal pump comprises 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 with an impeller, a shaft sleeve is fixedly connected to the pump shaft in a sealing mode, and a pump cover is arranged outside the shaft sleeve in a clearance sleeving mode and comprises a first sealing installation part, a second sealing installation part and an installation connection part. The mounting through hole is in clearance fit with the periphery of the shaft sleeve, a first sealing piece is arranged between the periphery of the second sealing mounting part and the inner periphery of the pump body, an elastic piece is arranged between the second sealing mounting part and the bracket, and an axial clearance is formed between the end, close to the impeller, of the mounting connecting part and the impeller; one end of the mechanical seal is fixedly connected with the first seal mounting part, and the other end is fixedly connected with the shaft sleeve. The abrasion of the mechanical seal can be reduced, and the service life is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of pumps, and in particular relates to a high-pressure centrifugal pump. Background Art

[0002] High-pressure centrifugal pump is a mechanical device that uses the principle of centrifugal force to transport liquid. It is mainly used in occasions that require high pressure, such as high-rise water supply, fire protection systems, etc. Centrifugal pumps use 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 dynamic seal ring is connected to the shaft and rotates together, and the other static seal ring is fixed on the shell. The dynamic seal ring and the static seal ring are subjected to axial force so that the sealing surface of the dynamic seal ring and the sealing surface of the static seal ring always maintain friction contact. This stable contact can prevent leakage from the sealing surface or minimize the leakage. However, when the mechanical seal is installed in the high-pressure centrifugal pump, when the high-pressure centrifugal pump inhales a large flow of liquid into the impeller, the impeller will be subjected to axial thrust, and the axial thrust will be transmitted to the pump shaft, causing the pump shaft to vibrate in the axial direction, resulting in fluctuations in the contact pressure of the sealing surface, aggravated 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 it more effective and ensure the stability of the working pressure in the high-pressure centrifugal pump. Summary of the invention

[0003] In view of the deficiencies in the prior art, an object of the present invention is to provide a high-pressure centrifugal pump.

[0004] The objectives of the present invention can be achieved through the following technical solutions: A high-pressure centrifugal pump comprises a pump body with a pump cavity 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, the impeller is located in the pump cavity, a shaft sleeve is seal-fixedly connected to the pump shaft, a pump cover is arranged in a gap outside the shaft sleeve, the pump cover comprises a first sealing mounting portion, a second sealing mounting portion and a mounting connection portion that smoothly connects the first sealing mounting portion and the second sealing mounting portion, a mounting through hole is provided in the middle of the first sealing mounting portion, the mounting through hole is gap-matched with the outer periphery of the shaft sleeve, a sealing member 1 is provided between the outer periphery of the second sealing mounting portion and the inner periphery of the pump body, an elastic member is provided between the second sealing mounting portion and the bracket, an axial gap is provided 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 sealing mounting portion, and the other end is fixedly connected to the shaft sleeve.

[0005] The pump cover is connected to the pump body by sliding connection. The sealing member provides radial support and sealing for the pump cover. The pump cover is fixed to the end of the mechanical seal. The mechanical seal provides axial support and sealing for the pump cover. The elastic member assists the mechanical seal to adapt to the axial displacement caused by thermal expansion or pressure fluctuation, thereby reducing the wear of the mechanical seal and extending its service life.

[0006] Furthermore, the impeller has a flow limiting portion protruding toward the pump cover, the mounting 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 the gap, reduces the impeller back pressure, and improves the pump efficiency of the high-pressure centrifugal pump.

[0007] Furthermore, the pump shaft includes a first fixing part, a second fixing part and a third fixing part, the diameter of which increases once, the first fixing part is provided with a fixed inducer, one end of the inducer abuts against the impeller, the impeller is fixed to the second fixing part by a long key, the sleeve has a positioning bump protruding toward the pump shaft, one end of the impeller away from the inducer abuts against the positioning bump, and the other end face of the positioning bump abuts against the shaft shoulders of the second fixing part and the third fixing part. The inducer, impeller and sleeve are rotated as one body, 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.

[0008] Furthermore, the shaft sleeve and the impeller respectively have an axially straight long groove one and a long groove two, and the outer periphery of the second fixing portion is provided with a long groove three, and the long key is located in the long groove one, the long groove two and the long groove 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 which are directly connected to each other and whose inner diameters increase successively. The first mounting hole is directly connected to the pump chamber, and the second sealing mounting portion is provided with a sealing groove relative to the first mounting hole, and the sealing member is located in the sealing groove.

[0011] Furthermore, a positioning ring protrudes from the second sealing 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, and an elastic member is arranged between the positioning ring and the bracket.

[0012] Furthermore, the mechanical seal comprises a static sealing part and a dynamic sealing part, wherein the static sealing part is sealed against the dynamic sealing part plane, an end of the static sealing part away from the dynamic sealing part is sealed and fixedly connected to the first sealing mounting part, and the dynamic sealing part is sealed and fixedly connected to the shaft sleeve.

[0013] Furthermore, the static sealing part includes a static pressure seat, a sealing member 3 is fixedly arranged between the end of the static pressure seat close to the pump cover and the pump cover, and the end of the static pressure seat away from the pump cover is sealed and fixedly connected to the static sealing ring, and the dynamic sealing part includes a dynamic pressure seat, a dynamic buffer ring and a dynamic sealing ring are circumferentially fixed to the side wall of the dynamic pressure seat, a sealing ring is arranged between the dynamic sealing ring and the shaft sleeve, a circumferentially uniformly distributed first reset member is arranged between the dynamic sealing ring and the dynamic buffer ring, a circumferentially uniformly distributed second reset member is arranged between the dynamic buffer ring and the bottom wall of the dynamic pressure seat, and the first reset member and the second reset member are staggered. The staggered arrangement of the first reset member and the second reset member allows more first reset members and second reset members to be arranged, so that the dynamic sealing part evenly distributes the pressure, avoids eccentric wear of the static sealing ring and the dynamic sealing ring, and improves the sealing stability under high pressure.

[0014] Furthermore, at least two first blind holes and second blind holes are provided on the dynamic buffer ring, the first blind hole opening faces the dynamic sealing ring, the second blind hole opening faces the bottom wall of the dynamic pressure seat, the first blind holes and the second blind holes are equal in number and are spaced apart from each other, the first reset member is located in the first blind hole, and the second reset member is located in the second blind hole.

[0015] Compared with the prior art, the technical effects of the present invention are as follows: 1. The pump cover and the pump body are connected by sliding, and the seal-pump cover is used for radial support and sealing. The pump cover is fixed at the end of the mechanical seal, and the mechanical seal is used to axially support and seal the pump cover. The elastic part assists the mechanical seal to adapt to the axial displacement caused by thermal expansion or pressure fluctuations, thereby reducing the wear of the mechanical seal and extending the service life. 2. The sleeve forms a rigid contact with the pump shaft shoulder and the impeller through the positioning bump, and directly transmits the axial thrust generated by the impeller to the pump shaft bearing system, thereby preventing 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 in the high-pressure centrifugal pump. 2. The inducer, impeller and sleeve are rotated as one, thereby 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 It is a cross-sectional view of the present invention.

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

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

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

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

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

[0022] Figure number marking: 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 part; 302. Second fixing part; 303. Third fixing part; 304. Long groove three; 4. Impeller; 401. Flow limiting part; 402. Long groove two; 5. Bushing; 501. Positioning convex block; 502. Long groove one; 6. Pump cover; 601. First sealing mounting part; 602. Second sealing mounting part; 603. Mounting connection part; 604. Mounting Through hole; 605, flow limiting hole; 606, sealing groove; 607, positioning ring; 7, seal one; 8, elastic member; 9, inducer; 10, long key; 11, seal two; 12, static sealing part; 1201, static pressure seat; 1202, seal three; 1203, static sealing ring; 13, dynamic sealing part; 1301, dynamic pressure seat; 1302, dynamic buffer ring; 1303, dynamic sealing ring; 1304, sealing ring; 1305, first reset member; 1306, second reset member; 1307, first blind hole; 1308, second blind hole. DETAILED DESCRIPTION

[0023] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0024] It should be noted that the descriptions of the present invention regarding directions such as “up”, “down”, “left”, “right”, “top” and “bottom” are all defined based on the relationships between the orientations or positions shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device must be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0025] according to Figures 1 to 6As shown, a high-pressure centrifugal pump comprises 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 mounted in the pump body 1 and the bracket 2, a mechanical seal is arranged 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 sealed and fixedly connected to the pump shaft 3, and a pump cover 6 is provided in a clearance sleeve outside the shaft sleeve 5. The pump cover 6 adopts a non-rigid connection, and the pump cover 6 comprises a first sealing mounting portion 601, a second sealing mounting portion 602, and a mounting connection portion 603 which smoothly connects 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, and the mounting through hole 604 is in clearance with the outer periphery of the shaft sleeve 5. 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 clearance is provided 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 sealing mounting portion 601, and the other end is fixedly connected to the shaft sleeve 5.

[0026] The impeller 4 has a flow limiting portion 401 protruding toward the pump cover 6, and the mounting 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 the 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 sealing portion 12 and a dynamic sealing portion 13. The static sealing portion 12 and the dynamic sealing portion 13 are flatly sealed against each other, and the end of the static sealing portion 12 away from the dynamic sealing portion 13 is sealed and fixedly connected to the first sealing mounting portion 601, and the dynamic sealing portion 13 is sealed and fixedly connected to the shaft sleeve 5. The static sealing part 12 includes a static pressure seat 1201, a sealing member 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 includes a dynamic pressure seat 1301, a dynamic buffer ring 1302 and a dynamic sealing ring 1303 are circumferentially fixed to the side wall of the dynamic pressure seat 1301, a sealing ring 1304 is arranged between the dynamic sealing ring 1303 and the shaft sleeve 5, a first reset member 1305 uniformly distributed in the circumference is arranged between the dynamic sealing ring 1303 and the dynamic buffer ring 1302, a second reset member 1306 uniformly distributed in the circumference 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. The first reset member 1305 and the second reset member 1306 are staggered so that more first reset members 1305 and second reset members 1306 can be arranged, so that the dynamic sealing part 13 is evenly distributed with pressure, and the eccentric wear of the static sealing ring 1203 and the dynamic sealing ring 1303 is avoided, and the sealing stability under high pressure is improved. At least two first blind holes 1307 and second blind holes 1308 are arranged on the dynamic buffer ring 1302, the first blind hole 1307 opens toward the dynamic sealing ring 1303, and 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 arranged at intervals 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.

[0027] 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 mutually connected and whose inner diameters increase successively. The first mounting hole 102 is directly connected with 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 7 is located in the sealing groove 606. A positioning ring 607 is protruded from the second sealing mounting portion 602 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. An elastic member 8 is provided between the positioning ring 607 and the bracket 2.

[0028] The pump cover 6 is connected to the pump body 1 by sliding, and the seal 7 radially supports and seals the pump cover 6. The pump cover 6 is fixed to 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, thereby reducing the wear of the mechanical seal and extending its service life.

[0029] The pump shaft 3 includes a first fixed part 301, a second fixed part 302 and a third fixed part 303, the diameter of which increases once. The first fixed part 301 is provided with a fixed inducer 9, one end of the inducer 9 abuts against the impeller 4, and the impeller 4 is fixed to the second fixed part 302 through a long key 10. The sleeve 5 has a positioning protrusion 501 protruding toward the pump shaft 3, and 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 shaft shoulders of the second fixed part 302 and the third fixed part 303. The sleeve 5 and the impeller 4 have an axial straight long groove 1 502 and a long groove 2 402, respectively. The outer periphery of the second fixed part 302 is provided with a long groove 3 304, and the long key 10 is located in the long groove 1 502, the long groove 2 402 and the long groove 3 304. A seal 2 11 is fixedly provided between the sleeve 5 and the third fixed part 303. The inducer 9, the impeller 4 and the shaft sleeve 5 are formed to rotate as a whole, so as to reduce the loss of torque on the pump shaft 3 caused by the inconsistent rotation among the three, and improve the pump efficiency of the high-pressure centrifugal pump.

[0030] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in 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 provided in a clearance sleeve outside 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); the mounting through hole (604) is clearance-matched with the outer periphery of the shaft sleeve (5); 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 clearance is provided 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 sealing mounting portion (601), and the other end is fixedly connected to the shaft sleeve (5).

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 are increased once. 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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