Multi-stage centrifugal pump

Abstract

The utility model provides a multi-stage centrifugal pump, and belongs to the technical field of centrifugal pumps. The problems that in the prior art, an impeller is insufficient in strength, and a balance disc is poor in balance effect are solved. The multi-stage impeller pump comprises a front pump shell, a middle pump shell, a rear pump shell, a pump shaft and a multi-stage impeller assembly, a water inlet shell is fixedly connected between the front pump shell and the middle pump shell, a water outlet shell is fixedly connected between the rear pump shell and the middle pump shell, and the multi-stage impeller assembly is installed in the middle pump shell and comprises an impeller body and a balance disc. A reinforcing ring is integrally formed on the rear side of the impeller body, a pressure groove is formed in one side of the reinforcing ring, an inclined face structure is formed in the middle of one side of the balance disc, a first plane and a second plane are formed in the outer ring portion and the inner ring portion of the balance disc respectively, and a limiting ring is formed between the inclined face structure and the second plane and arranged on the outer side of the reinforcing ring in a sleeving mode. The first plane is attached to the rear end face of the impeller body, and the second plane is attached to the end face of the reinforcing ring. The impeller has the advantages of being high in impeller strength and good in balance effect.

Description

TECHNICAL FIELD

[0001] The utility model belongs to centrifugal pump technical field relates to a multistage centrifugal pump. BACKGROUND

[0002] When multistage centrifugal pump works, axial force will be produced in each impeller, these axial forces are superimposed along the pump shaft direction, and the resultant force is often very large, so the multistage centrifugal pump has high requirement on balance.

[0003] The Chinese patent with patent publication number CN207686985U discloses a multistage centrifugal pump, which mainly comprises a pump body, a pump shaft, an impeller, a balance sleeve, a balance disc, a balance ring, a driving end bearing support component, a non-driving end bearing support component and a round nut. The non-driving end bearing support component comprises a rear bearing support, an angular contact ball bearing, a bearing box, a non-hole end cover, a hole end cover, a jacking bolt, a locking bolt, a rear adjusting bolt and a front adjusting bolt. A cylindrical roller bearing and a bearing top ring are arranged. A positioning convex ring is arranged on the inner wall of the rear bearing support. A cylindrical roller bearing installation shoulder is arranged on the pump shaft. The inner ring of the cylindrical roller bearing is fixed on the cylindrical roller bearing installation shoulder. The outer ring is fixedly connected with the positioning convex ring, so as to balance the radial force of the pump shaft. The inner end of the outer ring of the cylindrical roller bearing is in contact with the bearing top ring. The outer ring corresponds to the outer ring of the angular contact ball bearing. The other end of the bearing top ring is fixedly connected with the hole end cover. The hole end cover is fixedly connected with the rear bearing support through the adjusting bolt.

[0004] In the multistage centrifugal pump provided by the patent, the balance sleeve, the balance disc and the balance ring are arranged to enhance the balance. However, the axial gap of the balance disc is very small, which is not suitable for the working conditions of liquid containing sand in the pump, dry running of the pump or liquid close to gasification. The balance disc is easy to lose balance effect due to changes in working conditions. In addition, no structural reinforcement measures are arranged in the impeller, which may cause deformation or damage of the impeller during high-load operation. UTILITY MODEL CONTENTS

[0005] The utility model aims at the above problems existing in the prior art, and provides a multistage centrifugal pump.

[0006] The objective of this utility model can be achieved through the following technical solution: A multi-stage centrifugal pump includes a front pump casing, an intermediate pump casing, a rear pump casing, a pump shaft, and a multi-stage impeller assembly. An inlet casing is fixedly connected between the front pump casing and the intermediate pump casing, and an outlet casing is fixedly connected between the rear pump casing and the intermediate pump casing. The multi-stage impeller assembly is installed inside the intermediate pump casing. The multi-stage impeller assembly includes an impeller body and a balance disc. A reinforcing ring is integrally formed on the rear side of the impeller body. A pressure groove is formed on one side of the reinforcing ring. A keyway is formed inside the impeller body. A sloped structure is formed at the middle of one side of the balance disc. The outer ring and inner ring of the balance disc are respectively formed into a first plane and a second plane. A limiting ring is formed between the sloped structure and the second plane. The limiting ring is sleeved on the outside of the reinforcing ring. The first plane is in contact with the rear end face of the impeller body, and the second plane is in contact with the end face of the reinforcing ring.

[0007] In the aforementioned multistage centrifugal pump, the pump shaft is provided with several multistage pump keys, which are connected to keyways.

[0008] In the aforementioned multistage centrifugal pump, an inlet sealing ring and an outlet sealing ring are respectively provided near both ends of the pump shaft, and a first pressure cap and a second pressure cap are respectively fitted and fixed on the pump shaft outside the inlet sealing ring and the outlet sealing ring.

[0009] In the aforementioned multistage centrifugal pump, the inclined structure extends inward, and the angle of the inclined structure is 22°±2°.

[0010] Compared with the prior art, the multistage centrifugal pump provided by this utility model has the following beneficial effects: 1. The integrally formed reinforcing ring on the rear side of the impeller body enhances the structural strength of the impeller assembly. The pressure groove on the reinforcing ring further optimizes the pressure distribution. The limiting ring of the balance disc is sleeved on the outside of the reinforcing ring to ensure the precise fit between the balance disc and the impeller body and the reinforcing ring. The first plane fits with the rear end face of the impeller body, and the second plane fits with the end face of the reinforcing ring, making the assembly stable and reducing operating vibration; 2. The inclined structure of the balance disc extends inward, which can effectively adjust the fluid pressure distribution, balance the axial force generated during the operation of the multistage centrifugal pump, and improve the stability and reliability of the pump operation. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0012] Figure 2 This is a schematic diagram of the exploded structure of this utility model;

[0013] Figure 3 This is a schematic diagram of the impeller body structure;

[0014] Figure 4 This is a schematic diagram of the balance disc structure.

[0015] In the diagram: 1. Front pump casing; 2. Middle pump casing; 3. Rear pump casing; 4. Pump shaft; 41. Multistage pump key; 5. Multistage impeller assembly; 51. Impeller body; 511. Reinforcing ring; 512. Pressure groove; 513. Keyway; 52. Balance disc; 521. Inclined structure; 522. First plane; 523. Second plane; 524. Limiting ring; 6. Inlet casing; 7. Outlet casing; 8. Inlet sealing ring; 81. First pressure cap; 9. Outlet sealing ring; 91. Second pressure cap. 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] like Figures 1 to 4 As shown, this embodiment includes a front pump casing 1, an intermediate pump casing 2, a rear pump casing 3, a pump shaft 4, a multi-stage impeller assembly 5, and an outlet casing 7. The inlet casing 6 is fixedly connected between the front pump casing 1 and the intermediate pump casing 2, and the outlet casing 7 is fixedly connected between the rear pump casing 3 and the intermediate pump casing 2. The multi-stage impeller assembly 5 is installed inside the intermediate pump casing 2, and the pump shaft 4 passes through the multi-stage impeller assembly 5. The multi-stage impeller assembly 5 includes four impeller bodies 51 and three balance discs 52. Three sets of impeller bodies 51 and balance discs 52 are fixedly connected and connected to the pump shaft 4, and the remaining impeller bodies 51 are set separately and connected to the pump shaft 4.

[0018] like Figures 2 to 4 As shown, a reinforcing ring 511 is integrally formed on the rear side of the impeller body 51. The outer and inner ring portions of the balance disc 52 are respectively formed as a first plane 522 and a second plane 523. A sloped structure 521 is formed at the middle of one side of the balance disc 52. A limiting ring 524 is formed between the sloped structure 521 and the second plane 523. When the impeller body 51 and the balance disc 52 are connected and installed, the limiting ring 524 is sleeved on the outside of the reinforcing ring 511. The first plane 522 is in contact with the rear end face of the impeller body 51, and the second plane 523 is in contact with the end face of the reinforcing ring 511. The balance disc 52 is precisely matched with the impeller body 51 and the reinforcing ring 511 to effectively balance the axial force during operation in this embodiment. A pressure groove 512 is provided on the rear side of the reinforcing ring 511. When the impeller body 51 and the balance disc 52 are connected and installed, the rear end face of the reinforcing ring 511 is in contact with the second plane 523, and a gap is formed between the pressure groove 512 and the second plane 523. When the high-pressure liquid flows into the gap formed by the pressure groove 512 and the second plane 523, the cross-sectional area of ​​the flow channel suddenly expands, the liquid flow rate decreases, and the pressure between the impeller body 51 and the balance disc 52 is reduced.

[0019] Specifically, such as Figure 4As shown, the direction of the inclined surface structure 521 is extending inwardly, and the angle of the inclined surface structure 521 is 22°±2°.

[0020] Further, as shown in Figures 2 to 3 As shown, a key groove 513 is arranged on the inner ring surface of each impeller body 51, and a plurality of multi-stage pump keys 41 are arranged on the pump shaft 4, the pump keys are sequentially connected with the key grooves 513, so as to connect the multi-stage impeller assembly 5 with the pump shaft 4.

[0021] Further, as shown in Figure 2 As shown, the water inlet sealing ring 8 and the water outlet sealing ring 9 are respectively arranged on the pump shaft 4 close to the two ends, and the first gland 81 and the second gland 91 are respectively arranged on the outer side of the pump shaft 4 and are fixedly sleeved.

[0022] The specific embodiments described herein are merely illustrative of the spirit of the present application. Those skilled in the art to which the present application belongs can make various modifications or supplements to the described specific embodiments or use similar ways to replace, but will not deviate from the spirit of the present application or exceed the scope defined by the appended claims.

[0023] Although various terms are used herein, the possibility of using other terms is not excluded. The use of these terms is only for the convenience of describing and explaining the essence of the present application; any interpretation of them as any kind of additional limitation is contrary to the spirit of the present application.

Claims

1. A multistage centrifugal pump, comprising a front pump casing (1), an intermediate pump casing (2), a rear pump casing (3), a pump shaft (4), and a multistage impeller assembly (5), characterized in that: An inlet housing (6) is fixedly connected between the front pump housing (1) and the intermediate pump housing (2), and an outlet housing (7) is fixedly connected between the rear pump housing (3) and the intermediate pump housing (2). The multi-stage impeller assembly (5) is installed inside the intermediate pump housing (2). The multi-stage impeller assembly (5) includes an impeller body (51) and a balance disc (52). A reinforcing ring (511) is integrally formed on the rear side of the impeller body (51). A pressure groove (512) is provided on one side of the reinforcing ring (511). A keyway (51) is provided inside the impeller body (51). 3) A slope structure (521) is formed at the middle of one side of the balance disk (52). The outer ring and inner ring of the balance disk (52) are respectively formed as a first plane (522) and a second plane (523). A limiting ring (524) is formed between the slope structure (521) and the second plane (523). The limiting ring (524) is sleeved on the outside of the reinforcing ring (511). The first plane (522) is in contact with the rear end face of the impeller body (51), and the second plane (523) is in contact with the end face of the reinforcing ring (511).

2. A multistage centrifugal pump according to claim 1, characterized in that: The pump shaft (4) is provided with several multi-stage pump keys (41), and the pump keys are connected to the keyway (513).

3. A multistage centrifugal pump according to claim 1, characterized in that: The pump shaft (4) is provided with an inlet sealing ring (8) and an outlet sealing ring (9) near both ends. A first pressure cap (81) and a second pressure cap (91) are respectively fitted and fixed on the pump shaft (4) outside the inlet sealing ring (8) and the outlet sealing ring (9).

4. A multistage centrifugal pump according to claim 1, characterized in that: The inclined structure (521) extends inward, and the angle of the inclined structure (521) is 22°±2°.

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