Shield pump based on static balance rib axial force balance technology

Abstract

The invention discloses a shield pump based on a static balance rib axial force balance technology, and relates to the technical field of shield pumps. The axial force balancing device comprises a connecting body, a main impeller and an auxiliary impeller, the main impeller and the auxiliary impeller are coaxially linked, the matching surface of the connecting body and the main impeller adopts extension design and forms an axial force balancing flow channel, a balancing rib connected with the connecting body is arranged in the axial force balancing flow channel, and a part of medium serving as circulating liquid enters the inner side of the axial force balancing flow channel and then flows into the axial force balancing flow channel. A medium of high-pressure turbulent flow tends to be stable under the action of the balance ribs so as to receive axial force from the auxiliary impeller to achieve axial force balance. Complex structures of a balance disc and a balance disc seat are omitted, a simple structure with a better effect is used for replacement, the functions of three parts are achieved through one part, axial force balance is efficiently adjusted, the service life of the shield pump is effectively prolonged, the axial force is effectively balanced through test actual measurement data, and safe and efficient operation of the whole pump is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of canned motor pumps, and particularly relates to a canned motor pump based on static balance rib axial force balance technology. BACKGROUND

[0002] For some high-lift, small-flow large canned motor pumps conveying high-viscosity medium or high-temperature heat conducting oil, an automatic balance structure is needed. For the working condition of high-lift, small-flow large canned motor pumps conveying high-viscosity medium or high-temperature heat conducting oil, the on-site working condition requirement is harsh, axial force adjustment is difficult and unstable, the service life of the wearing parts is low, and the failure rate is high.

[0003] At present, the structure of adding a balance disc and a balance disc seat between the impeller and the connecting body is generally used to adjust the axial force, and different hydraulic impellers need to be designed with corresponding balance structures, which consumes a lot of effort from the design source, has high research and development and production costs, and has limited effect, which is not ideal. Therefore, the application provides a canned motor pump based on static balance rib axial force balance technology to solve the above problems. SUMMARY

[0004] The application aims to provide a canned motor pump based on static balance rib axial force balance technology, which cancels the complex structure of the balance disc and the balance disc seat by bold attempt, replaces the balance disc with an extended design of the connecting body, and replaces the balance disc seat with a balance rib welded on the connecting body and the impeller cooperation surface, so that three components achieve the function of one component, and the cost is reduced and the efficiency is improved.

[0005] To solve the above technical problems, the application is achieved by the following technical scheme: the application is a canned motor pump based on static balance rib axial force balance technology, comprising a connecting body, a main impeller and a secondary impeller coaxially connected, the cooperation surface of the connecting body and the main impeller is designed to be extended and forms an axial force balance flow channel, the axial force balance flow channel is internally provided with a balance rib connected with the connecting body, the balance rib adjusts the axial force at the front end of the pump by adjusting the leakage flow at the main impeller, and after part of the medium as circulating liquid enters the inside of the axial force balance flow channel, the high-pressure turbulent medium tends to be stable under the action of the balance rib to receive the axial force from the secondary impeller to achieve axial force balance.

[0006] The application is further provided as follows: the canned motor pump further comprises a pump body, the connecting body is installed on the inside of the pump body and coaxially arranged with the pump body, the main impeller is installed at the front end of the pump body and coaxially connected with the pump shaft, and the secondary impeller is installed at the rear end of the pump body and coaxially connected with the pump shaft.

[0007] The application further provides that the shield pump further comprises a rear bearing and a rear shaft sleeve installed inside the pump body, the rear bearing and the rear shaft sleeve are coaxially arranged and a flow guide gap a is formed between the rear bearing and the rear shaft sleeve, and a rear bearing seat is fixedly installed at the rear end of the pump body.

[0008] The application further provides that the shield pump further comprises a stator shield sleeve and a rotor shield sleeve installed inside the pump body, the stator shield sleeve and the rotor shield sleeve are coaxially arranged and a flow guide gap b is formed between the stator shield sleeve and the rotor shield sleeve, and the flow guide gap b is concentrically communicated with the flow guide gap a at the rear end thereof.

[0009] The application further provides that the shield pump further comprises a front bearing and a front shaft sleeve installed inside the pump body, the front bearing and the front shaft sleeve are coaxially arranged and a flow guide gap c is formed between the front bearing and the front shaft sleeve, and the flow guide gap c is concentrically communicated with the flow guide gap b at the rear end thereof.

[0010] The application further provides that the balance ribs are uniformly arranged on the end surface of the connecting body close to the main impeller, and the number and size of the balance ribs are determined according to the circulating amount, and the number and size of the balance ribs are different for different hydraulic pump types.

[0011] The application further provides that the main impeller is provided with an impeller liquid passage hole, the gap between the impeller liquid passage hole and the connecting body is 0.5 mm to ensure the dynamic and static interference, and the gap between the balance rib and the rear cover plate of the main impeller is 0.5 mm.

[0012] The application further provides that the shield pump further comprises a heat exchanger assembly installed at the top of the pump body, the connecting body is provided with a circulating liquid hole, and the rear end of the pump shaft is provided with a flow guide center hole; when the fluid enters the shield pump, the flow path of the fluid is divided into a main flow path and a circulating liquid path, the main flow path is that the fluid passes through the secondary impeller, enters the flow guide gap a between the rear bearing and the rear shaft sleeve, and then passes through the flow guide center hole at the rear end of the pump shaft to return to the secondary impeller.

[0013] The circulating liquid path is that the fluid passes through the secondary impeller, enters the flow guide gap b between the stator shield sleeve and the rotor shield sleeve, and then passes through the circulating liquid hole to enter the heat exchanger assembly, and then enters the flow guide center hole from the rear bearing seat and returns to the secondary impeller.

[0014] The application has the following beneficial effects: the application cancels the complex structure of the balance disc and the balance disc seat, uses a simple structure with better effect to replace the three components, realizes the functions of three components with one component, efficiently adjusts the axial force balance, effectively prolongs the service life of the shield pump, and through the test and measured data, the axial force is effectively balanced, and the whole pump realizes safe and efficient operation. BRIEF DESCRIPTION OF DRAWINGS

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a partial structural schematic diagram of the canned pump based on the static balancing rib axial force balancing technology of the present invention.

[0017] Figure 2 This is a schematic diagram of the structure of the shielded pump based on the static balance rib axial force balancing technology of the present invention.

[0018] Figure 3 This is a diagram showing the positional relationship between the connecting body and the balancing rib in this invention.

[0019] The attached diagram lists the components represented by each number as follows:

[0020] 1-Pump body, 2-Main impeller, 3-Connecting body, 4-Front bearing, 5-Front shaft sleeve, 6-Stator shield sleeve, 7-Rotor shield sleeve, 8-Heat exchanger assembly, 9-Rear bearing, 10-Rear shaft sleeve, 11-Pump shaft, 12-Auxiliary impeller, 13-Rear bearing housing. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figures 1-3This invention relates to a shielded pump based on static balancing rib axial force balancing technology, comprising a connecting body 3 and a coaxially linked main impeller 2 and auxiliary impeller 12. The mating surface between the connecting body 3 and the main impeller 2 is extended to form an axial force balancing flow channel. A balancing rib connected to the connecting body 3 is provided inside the axial force balancing flow channel. The balancing rib adjusts the axial force at the pump front end by regulating the discharge flow at the main impeller 2. After part of the circulating fluid enters the inner side of the axial force balancing flow channel, the high-pressure turbulent medium tends to stabilize under the action of the balancing rib, thus receiving the axial force from the auxiliary impeller 12 to achieve axial force balancing. In this embodiment, the front end of the connecting body 3, i.e., the mating surface with the main impeller 2, is extended. The extended part replaces the balance disc in the prior art, and after leaving a reasonable G-value space, several balancing ribs are welded to this surface. The balancing ribs are circumferentially arranged on the end face of the connecting body 3 near the main impeller 2. The number and size of the balancing ribs are determined by the circulation volume, and the number and size of the balancing ribs vary for different hydraulic pump types.

[0023] Because a secondary impeller 12 is installed at the tail of a large canned motor pump to pressurize the circulation, the axial force at the tail is too large, resulting in excessive stress on the vulnerable parts at the rear. We adjust the axial force at the front end by adjusting the discharge flow at the front impeller (i.e., the main impeller 2). This requires a greater forward axial force, so the circulation flow at the main impeller 2 needs to be reduced to increase the forward force, thereby balancing the excessive force at the rear end; for example... Figure 1 and Figure 2 As shown, the main impeller 2 is provided with an impeller liquid passage hole. The gap between the impeller liquid passage hole and the connecting body 3 is 0.5 mm to ensure dynamic and static interference. Eight 50×5×t6 stiffeners (i.e., balance ribs) are evenly welded on the connecting body 3. The gap between the balance ribs and the rear cover plate of the main impeller 2 is 0.5 mm. As the impeller rotates, a small portion of the medium flows as circulating liquid from the impeller balance hole to the gap between the impeller rear cover plate and the connecting body. The presence of the stiffeners makes this high-pressure turbulence tend to be a more stable flow field, ensuring the stability of the circulation volume and receiving the axial force from the end of the auxiliary impeller 12, thereby achieving balance.

[0024] In this embodiment of the invention, such as Figure 2 As shown, the canned motor pump also includes a pump body 1, with the connecting body 3 installed inside the pump body 1 and coaxially arranged. The main impeller 2 is installed at the front end of the pump body 1 and concentrically connected to the pump shaft 11, and the auxiliary impeller 12 is installed at the rear end of the pump body 1 and concentrically connected to the pump shaft 11. The canned motor pump also includes a rear bearing 9 and a rear shaft sleeve 10 installed inside the pump body 1. The rear bearing 9 and the rear shaft sleeve 10 are coaxially arranged and form a flow guiding gap a between them. A rear bearing seat 13 is fixedly installed at the rear end of the pump body 1, and the auxiliary impeller 12 is disposed inside the rear bearing seat 13.

[0025] In this embodiment of the invention, such asFigure 2 As shown, the canned motor pump also includes a stator shielding sleeve 6 and a rotor shielding sleeve 7 installed inside the pump body 1. The stator shielding sleeve 6 and the rotor shielding sleeve 7 are coaxially arranged and form a flow guiding gap b between them. The flow guiding gap b is concentrically connected to the flow guiding gap a at its rear end. The canned motor pump also includes a front bearing 4 and a front shaft sleeve 5 installed inside the pump body 1. The front bearing 4 and the front shaft sleeve 5 are coaxially arranged and form a flow guiding gap c between them. The flow guiding gap c is concentrically connected to the flow guiding gap b at its rear end.

[0026] In this embodiment of the invention, such as Figure 2 As shown, the canned pump also includes a heat exchanger assembly 8 installed on the top of the pump body 1. A circulating fluid hole is provided on the connecting body 3, and a flow guide center hole is provided at the rear end of the pump shaft 11. When fluid enters the canned pump, its flow path is divided into a main flow path and a circulating fluid path. The main flow path is that the fluid passes through the secondary impeller 12 and enters the flow guide gap a between the rear bearing 9 and the rear shaft sleeve 10, then passes through the flow guide center hole at the rear end of the pump shaft 11 and returns to the secondary impeller 12. The circulating fluid path is that the fluid passes through the secondary impeller 12 and enters the flow guide gap b between the stator shield sleeve 6 and the rotor shield sleeve 7, then enters the flow guide gap c between the front bearing 4 and the front shaft sleeve 5, passes through the circulating fluid hole into the heat exchanger assembly 8, then enters the flow guide center hole through the rear bearing seat 13 and returns to the secondary impeller 12. In this embodiment, the flow rate is 550 m³ / s. 3 / h, head = 70m, the conveying medium is heat transfer oil, temperature 20~370℃, as the temperature increases, the viscosity of the medium decreases. Taking the low temperature and high viscosity pump start-up conditions on site as an example, after implementing this solution, the axial force adjustment is within the qualified range and the operation is stable.

[0027] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0028] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A canned motor pump based on static balance of the axial force of the rotor shaft, characterized in that, The shielded pump comprises a connecting body (3), a main impeller (2) and a secondary impeller (12) coaxially connected, the connecting body (3) is provided with an extension design on the matching surface of the main impeller (2) and forms an axial force balance flow channel, the axial force balance flow channel is internally provided with a balance rib connected with the connecting body (3), the balance rib adjusts the axial force at the front end of the pump by adjusting the leakage flow at the main impeller (2), after part of the medium as circulating liquid enters the inside of the axial force balance flow channel, the high-pressure turbulent medium tends to be stable under the action of the balance rib to receive the axial force from the secondary impeller (12) to achieve axial force balance.

2. The canned motor pump based on static balance of the axial force of the rotor shaft according to claim 1, characterized in that, The shielded pump further comprises a pump body (1), the connecting body (3) is coaxially arranged inside the pump body (1), the main impeller (2) is coaxially connected with the pump shaft (11) and arranged at the front end of the pump body (1), and the secondary impeller (12) is coaxially connected with the pump shaft (11) and arranged at the rear end of the pump body (1).

3. The canned motor pump based on static balance of the axial force of the shaft according to claim 2, characterized in that, The shielded pump further comprises a rear bearing (9) and a rear shaft sleeve (10) arranged inside the pump body (1), the rear bearing (9) and the rear shaft sleeve (10) are coaxially arranged and form a flow guide gap a therebetween, the rear end of the pump body (1) is fixedly provided with a rear bearing seat (13), and the secondary impeller (12) is arranged inside the rear bearing seat (13).

4. The canned motor pump based on static balance of the axial force of the rotor shaft according to claim 3, characterized in that, The shielded pump further comprises a stator shield sleeve (6) and a rotor shield sleeve (7) arranged inside the pump body (1), the stator shield sleeve (6) and the rotor shield sleeve (7) are coaxially arranged and form a flow guide gap b therebetween, and the flow guide gap b is coaxially communicated with the flow guide gap a at the rear end thereof.

5. The shielded pump based on the static balance of the axial force of the muscle based on the static balance of the axial force of the muscle according to claim 4, characterized in that, The shielded pump further comprises a front bearing (4) and a front shaft sleeve (5) arranged inside the pump body (1), the front bearing (4) and the front shaft sleeve (5) are coaxially arranged and form a flow guide gap c therebetween, and the flow guide gap c is coaxially communicated with the flow guide gap b at the rear end thereof.

6. The canned motor pump based on static balance of the axial force of the rotor shaft according to claim 5, characterized in that, The balance ribs are arranged on the end face of the connecting body (3) close to the main impeller (2), and the number and size of the balance ribs are determined according to the circulating amount, and the number and size of the balance ribs are different for different types of hydraulic pumps.

7. The canned motor pump based on static balance of the axial force of the rotor shaft according to claim 6, characterized in that, The main impeller (2) is provided with an impeller liquid passage, the gap between the impeller liquid passage and the connecting body (3) is 0.5 mm to ensure the dynamic and static interference, and the gap between the balance rib and the rear cover plate of the main impeller (2) is 0.5 mm.

8. The canned motor pump based on static balance of the axial force of the rotor shaft according to claim 7, characterized in that, The shielded pump further comprises a heat exchanger assembly (8) arranged on the top of the pump body (1), the connecting body (3) is provided with a circulating liquid hole, and the rear end of the pump shaft (11) is provided with a flow guide center hole. When the fluid enters the shielded pump, the flow path is divided into a main flow path and a circulating liquid path, the main flow path is that the fluid passes through the secondary impeller (12), enters the flow guide gap a between the rear bearing (9) and the rear shaft sleeve (10), and then passes through the flow guide center hole at the rear end of the pump shaft (11) to return to the secondary impeller (12); The circulation liquid path is that the fluid passes through the secondary impeller (12) into the guide gap b between the stator shield sleeve (6) and the rotor shield sleeve (7), passes through the circulation liquid hole into the heat exchanger assembly (8) after entering the guide gap c between the front bearing (4) and the front shaft sleeve (5), and then enters the guide center hole from the rear bearing seat (13) and returns to the secondary impeller (12).

Images