Single-suction centrifugal pump shaft sleeve capable of balancing axial force

Abstract

The utility model discloses a single-suction centrifugal pump shaft sleeve capable of balancing axial force. The single-suction centrifugal pump shaft sleeve comprises a pump shaft. The pump shaft sleeve is provided with a mechanical seal gland; the end of the pump shaft is fixedly connected with an impeller. A shaft sleeve A, a tension spring and a shaft sleeve B are arranged at the positions, corresponding to the position between the mechanical seal gland and the impeller, of the pump shaft in a sleeving mode, the shaft sleeve A is connected with the shaft sleeve B through the tension spring, the shaft sleeve B is in interference fit with the pump shaft, and therefore the tension spring can always apply pull-back force to the impeller to counteract suddenly-applied axial force when the impeller rotates. After the impeller rotates stably, the impeller can offset additional axial force through a tension spring, and the impeller is matched with a balance hole formed in the impeller to achieve the purpose that the pressure of a water inlet port and the pressure of a water outlet port in the pump shell are relatively balanced, so that a bearing is protected, and the service life of the pump shell is prolonged. And the bearing is prevented from being seriously damaged when deviating from a working condition point high-efficiency area.

Description

TECHNICAL FIELD

[0001] The utility model belongs to centrifugal pump technical field, specifically, relate to a single suction centrifugal pump shaft sleeve of balanced axial force. BACKGROUND

[0002] The axial force is the reverse tension or pressure on the structure or a certain normal section caused by the action. The axial force generated in the operation of the single-stage centrifugal pump is mainly generated from the pressure asymmetry of the impeller two sides, the dynamic reaction force when the impeller is sucked, the internal and external pressure difference of the shaft end and the shaft base part, the arrangement mode of the rotor self weight and the like.

[0003] The balance of the axial force of the single suction centrifugal pump can eliminate part of the axial force by the impeller vice blade or balance hole mode in the hydraulic aspect, and the residual axial force is borne by the bearing of the pump. Since the elimination of the axial force in the hydraulic aspect is based on the design and calculation of the original impeller of each specification pump, high efficiency area operating point, when the impeller outer diameter needs to be changed or deviates from the high efficiency area operating point, the pump rotor will generate additional axial force, which greatly increases the load of the bearing, affects the service life of the bearing, and also destroys the reliability of the shaft seal. SUMMARY

[0004] In order to solve the technical problem that the bearing bears large force, the service life of the bearing is reduced and the bearing is easily damaged due to the unideal blade balance axial force, the utility model provides a single suction centrifugal pump shaft sleeve capable of balancing axial force.

[0005] The purpose of the utility model can be realized through the following technical schemes:

[0006] A single suction centrifugal pump shaft sleeve capable of balancing axial force, comprising a pump shaft, a mechanical seal cover is arranged on the pump shaft sleeve, an impeller is fixedly connected to the end of the pump shaft, a shaft sleeve A, a tension spring and a shaft sleeve B are sleeved on the position corresponding to the mechanical seal cover and the impeller of the pump shaft respectively, the two ends of the tension spring are fixedly connected with the shaft sleeve A and the shaft sleeve B respectively, a plurality of countersunk holes in circumferential array are arranged on the end face of the shaft sleeve A, a corresponding threaded hole is arranged on the position corresponding to the countersunk hole of the impeller, and a screw is arranged in the corresponding countersunk hole and threaded hole.

[0007] Further, the shaft sleeve A and the pump shaft are gap-fitted, the shaft sleeve B and the pump shaft are interference-fitted, the position of the shaft sleeve A is located on the side close to the impeller, and the position of the shaft sleeve B is located on the side close to the mechanical seal cover.

[0008] Further, the shaft sleeve A is fixedly connected with symmetrically arranged protrusions, the shaft sleeve B is fixedly connected with symmetrically arranged recesses, and the protrusions are slidably connected in the recesses.

[0009] Further, the shaft sleeve B abuts against the mechanical seal cover.

[0010] Further, the impeller is provided with a limiting slot, and the pump shaft is provided with a key groove corresponding to the limiting slot; and a movable key is arranged in the key groove and extends into the limiting slot.

[0011] Further, the pump shaft is fixedly connected with a threaded shaft at the center of the end surface close to the mechanical seal cover, the impeller is sleeved on the threaded shaft between the mechanical seal cover and the threaded shaft, a pressing plate is sleeved on the threaded shaft, the pressing plate has a circular structure and an outer diameter larger than the inner diameter of the impeller, and the pressing plate is in abutment with the impeller, and a nut is threadedly connected to the threaded shaft corresponding to the outer side of the pressing plate.

[0012] The utility model discloses beneficial effects:

[0013] 1) the utility model discloses the cooperation of screw and threaded hole with impeller through the shaft sleeve A, make the synchronous movement of the integrated state between impeller and shaft sleeve A, when the motor starts to drive the impeller rotation through the bearing, the impeller makes the water inlet port and the water outlet port pressure of pump shell suddenly change greatly through centrifugal force, at this time, the shaft sleeve A is connected with the shaft sleeve B through the tension spring, and the shaft sleeve B is in interference fit with the pump shaft, therefore, the tension spring can always exert a back pull on the impeller to offset the axial force suddenly exerted when the impeller rotates, avoid the impeller to touch the pump shell and wear, after the stable rotation of the impeller, the impeller can also offset the additional axial force through the tension spring, and the balance hole arranged on the impeller is cooperated to realize the relative balance of the water inlet port and the water outlet port on the pump shell body, thereby protecting the bearing and avoiding the bearing from being seriously damaged when running in the high-efficiency area deviating from the working point.

[0014] 2) the utility model discloses the cooperation of the convex block on the shaft sleeve A and the concave block on the shaft sleeve B, and the pump shaft can drive the shaft sleeve A to rotate synchronously through the shaft sleeve B due to the interference fit between the shaft sleeve B and the pump shaft, the key groove arranged on the pump shaft, the detachable movable key and the limiting slot arranged on the impeller are cooperated to realize the transmission of the circumferential force of the pump shaft to the impeller, drive the impeller to rotate, thereby realizing the balance of the circumferential force on both sides of the impeller, and the pump shaft and the impeller run stably, thereby avoiding the bearing from being severely worn. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment description, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creating labor.

[0016] Figure 1 It is the whole structure schematic diagram of the utility model;

[0017] Figure 2The utility model discloses a cross section view of pump shaft in the utility model;

[0018] Figure 3 The utility model discloses an explosion view of pump shaft in the utility model;

[0019] Figure 4 The utility model discloses an explosion view of tension spring in the utility model;

[0020] In the drawing, the component list that each sign represents is as follows:

[0021] 1, pump shaft;2, impeller;3, mechanical seal cover;4, threaded shaft;5, nut;6, pressing piece;7, key groove;8, movable key;9, limiting groove;10, shaft sleeve A;11, shaft sleeve B;12, tension spring;13, protruding block;14, recessed block;15, countersunk hole;16, screw;17, threaded hole. Specific implementation

[0022] The technical scheme in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model and not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0023] Please refer to Figure 1 and Figure 3 As shown in the figure, a single-suction centrifugal pump shaft sleeve capable of balancing axial force comprises a pump shaft 1;The pump shaft 1 is provided with a mechanical seal cover 3, which is used for sealing the pump housing;The end surface center of the pump shaft 1 close to the mechanical seal cover 3 is fixedly connected with a threaded shaft 4;The pump shaft 1 is provided with an impeller 2 corresponding to the position between the threaded shaft 4 and the mechanical seal cover 3;The threaded shaft 4 is provided with a pressing piece 6, which is a circular structure, and the outer diameter is greater than the inner diameter of the impeller 2, and is attached to the impeller 2;The threaded shaft 4 is provided with a nut 5 corresponding to the position outside the pressing piece 6, which is used for fixing the pressing piece 6 on the threaded shaft 4, so as to limit the position of the pressing piece 6, and further limit the position of the impeller 2.

[0024] Please refer to Figure 2 and Figure 3 As shown in the figure, the impeller 2 is provided with a limiting groove 9, which is opened along the axial direction of the pump shaft 1;The pump shaft 1 is provided with a key groove 7 corresponding to the position of the limiting groove 9;The key groove 7 is provided with a movable key 8, which extends to the inside of the limiting groove 9, which is used for limiting the circumferential position of the impeller 2 on the pump shaft 1.

[0025] Please refer to Figure 3 and Figure 4As shown, the pump shaft 1 corresponds to the position between the mechanical seal cover 3 and the impeller 2, and is sleeved with the shaft sleeve A10, the tension spring 12 and the shaft sleeve B11, respectively, and the two ends of the tension spring 12 are fixedly connected with the shaft sleeve A10 and the shaft sleeve B11, respectively; the shaft sleeve B11 abuts against the mechanical seal cover 3; the shaft sleeve A10 is located on the side close to the impeller 2, and the shaft sleeve B11 is located on the side close to the mechanical seal cover 3; the shaft sleeve A10 is in clearance fit with the pump shaft 1; the shaft sleeve B11 is in interference fit with the pump shaft 1; the shaft sleeve A10 is fixedly connected with the symmetrically arranged protruding blocks 13; the shaft sleeve A10 is provided with a plurality of countersunk holes 15 in a circumferential array on the end face; the impeller 2 is provided with a corresponding threaded hole 17 at the position corresponding to the countersunk hole 15; the corresponding countersunk hole 15 and threaded hole 17 are internally provided with a screw 16 for fixing the shaft sleeve A10 and the impeller 2; the shaft sleeve B11 is fixedly connected with the symmetrically arranged recessed blocks 14, and the protruding block 13 is slidingly connected in the recessed block 14.

[0026] In order to facilitate the understanding of the above technical scheme of the utility model, the working principle or operation mode of the utility model in the actual process will be described in detail as follows:

[0027] In order to overcome the defects that the bearing is easily damaged and the service life is reduced due to the fact that the blade balance axial force is not ideal, the shaft sleeve A10 is connected with the impeller 2 through the cooperation of the screw 16 and the threaded hole 17, so that the impeller 2 and the shaft sleeve A10 are in a synchronous moving integrated state, when the motor starts to drive the impeller 2 to rotate through the bearing, the impeller 2 makes the pressure difference of the water inlet port and the water outlet port of the pump shell suddenly change through the centrifugal force, at this time, the shaft sleeve A10 is connected with the shaft sleeve B11 through the tension spring 12, and the shaft sleeve B11 is in interference fit with the pump shaft 1, therefore, the tension spring 12 can always exert a back pulling force on the impeller 2, so as to offset the sudden axial force exerted when the impeller 2 rotates, avoid the impeller 2 from suddenly touching the pump shell and being abraded, after the impeller 2 is stably rotated, the impeller 2 can also offset the additional axial force through the tension spring 12, and cooperate with the balance hole (it is prior art, not shown in the figure) provided on the impeller 2 to achieve the purpose of relatively balancing the pressure of the water inlet port and the water outlet port on the pump shell body, so as to protect the bearing and avoid the bearing from being severely damaged when it deviates from the high efficiency area of the working condition point.

[0028] Since the mechanical seal cover 3 is connected with the pump shell body, and the shaft sleeve B11 abuts against the mechanical seal cover 3, the position of the shaft sleeve B11 can be limited by the pump shell body, so as to avoid the pump shaft 1 from moving to the side away from the impeller 2, thereby ensuring that the impeller 2 remains stable under the action of the tension spring 12, achieving the purpose of balancing the axial force, and achieving the effect of protecting the bearing.

[0029] Wherein, by the cooperation of the convex block 13 on the shaft sleeve A10 and the concave block 14 on the shaft sleeve B11, and due to the interference fit between the shaft sleeve B11 and the pump shaft 1, the pump shaft 1 can drive the shaft sleeve A10 to rotate synchronously through the shaft sleeve B11; through the cooperation of the key groove 7 on the pump shaft 1, the detachable movable key 8 and the limiting slot 9 on the impeller 2, the circumferential force transmission purpose of the pump shaft 1 to the impeller 2 is realized, the impeller 2 is driven to rotate, so as to realize the balance of the circumferential force transmission on both sides of the impeller 2, and the pump shaft 1 and the impeller 2 run stably, thereby avoiding the strong wear of the bearing.

[0030] In the description of the specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the utility model. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0031] The above is only an example and description of the structure of the utility model, and those skilled in the art can make various modifications or supplements to the described specific embodiments or replace them with similar ways, as long as they do not deviate from the structure of the utility model or exceed the scope defined by the claims, which shall belong to the protection scope of the utility model.

Claims

1. A single-suction centrifugal pump shaft sleeve capable of balancing axial force, comprising a pump shaft (1); the pump shaft (1) is sleeved with a mechanical seal cover (3); and a impeller (2) is fixedly connected to the end of the pump shaft (1); Characterized in that: The pump shaft (1) is sleeved with a shaft sleeve A (10), a tension spring (12) and a shaft sleeve B (11) at positions corresponding to the mechanical seal cover (3) and the impeller (2) respectively, and the two ends of the tension spring (12) are fixedly connected with the shaft sleeve A (10) and the shaft sleeve B (11) respectively; A plurality of countersunk holes (15) are arranged in a circumferential array on the end face of the shaft sleeve A (10); a corresponding threaded hole (17) is arranged on the impeller (2) at a position corresponding to the countersunk hole (15); and a screw (16) is arranged inside the mutually corresponding countersunk hole (15) and threaded hole (17).

2. The single suction centrifugal pump impeller of claim 1, wherein: The shaft sleeve A (10) and the pump shaft (1) are in clearance fit; the shaft sleeve B (11) and the pump shaft (1) are in interference fit; the shaft sleeve A (10) is located on the side close to the impeller (2), and the shaft sleeve B (11) is located on the side close to the mechanical seal cover (3).

3. The single suction centrifugal pump impeller of claim 2, wherein: Symmetrically arranged protrusions (13) are fixedly connected to the shaft sleeve A (10); symmetrically arranged recesses (14) are fixedly connected to the shaft sleeve B (11), and the protrusions (13) are slidingly connected in the recesses (14).

4. The single suction centrifugal pump impeller of claim 1, wherein: The shaft sleeve B (11) abuts against the mechanical seal cover (3).

5. The single suction centrifugal pump impeller of claim 1, wherein: A limiting groove (9) is arranged on the impeller (2), and the limiting groove (9) is arranged in the axial direction of the pump shaft (1); a key groove (7) is arranged on the pump shaft (1) at a position corresponding to the limiting groove (9); and a movable key (8) is arranged in the key groove (7), and the upper part of the movable key (8) extends into the limiting groove (9).

6. The single suction centrifugal pump impeller of claim 1, wherein: A threaded shaft (4) is fixedly connected to the center of the end face of the pump shaft (1) close to the mechanical seal cover (3); the impeller (2) is sleeved on the pump shaft (1) at a position between the threaded shaft (4) and the mechanical seal cover (3); a pressing piece (6) is sleeved on the threaded shaft (4), the pressing piece (6) has a circular structure, the outer diameter of the pressing piece (6) is greater than the inner diameter of the impeller (2), and the pressing piece (6) is in contact with the impeller (2); and a nut (5) is threadedly connected to the threaded shaft (4) at a position corresponding to the outer side of the pressing piece (6).

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