Multi-stage shield pump capable of prolonging service life

Abstract

The invention provides a multistage shield pump capable of prolonging the service life. The multistage shield pump comprises a machine base, a machine shell, a pump shell, a pump body, an upper bearing, a middle bearing, a lower bearing, a rotor, a stator, an upper sheath, a lower sheath, a motor rotating shaft and an impeller shaft. The upper sheath, the lower sheath and the outer wall of the stator are sleeved with an integrally-formed stator shielding sleeve, the part covering the stator core is a stator shielding sleeve a, the part covering the upper sheath and the lower sheath is a stator shielding sleeve b, a gap a is formed between the stator shielding sleeve a and the rotor shielding sleeve, a gap b is formed between the stator shielding sleeve b and the rotor shielding sleeve, and the stator shielding sleeve a and the stator shielding sleeve b are integrally formed. The distance of the gap b is greater than that of the gap a; a lower thrust plate sleeved on the rotating shaft is arranged above the lower bearing; and the lower bearing is provided with a flow guide groove and an axial thrust balance groove. The shield pump can be effectively prevented from moving, shaking and mutual interference friction, the axial force of the rotor can be reduced, abrasion of the lower thrust plate is reduced, and the service life of the shield pump is prolonged.

Description

Technical Field

[0001] The invention relates to the field of shielded pumps, in particular to a multi-stage shielded pump capable of increasing service life. Background Art

[0002] The rotor and stator of the shielded pump are wrapped with a shielding sleeve. There is a small gap between the rotor shielding sleeve and the stator shielding sleeve, and the upper and lower ends of the stator shielding sleeve are welded. Due to the process precision, the rotor shielding sleeve has slight deformation at the welding point. Since the gap between the rotor and stator shielding sleeves is very small, due to the welding deformation, there is friction between the rotor shielding sleeve and the stator shielding sleeve, which affects the service life of the shielded motor. Secondly, during the use of the shielded pump, the rotor will generate a downward axial force under its own gravity, which will cause the thrust plate to wear during long-term use, greatly affecting the service life of the multi-stage shielded pump. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a multi-stage canned pump with a longer service life, so as to solve the technical problems raised in the above-mentioned background technology.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] A multi-stage shielded pump capable of improving service life comprises a machine base, a machine casing, a pump casing, and a pump body arranged from top to bottom, an upper bearing is installed on the top of the machine base through an upper bearing seat, a middle bearing is installed on the bottom of the machine base through a middle bearing seat, a motor shaft is installed between the upper bearing and the middle bearing, the motor shaft extends downward to the inner cavity of the machine casing and is connected to an impeller shaft extending into the pump casing through a shaft link key, the impeller shaft is arranged concentrically with the motor shaft; a rotor is sleeved on the motor shaft, and a rotor is arranged on the outer wall of the rotor A shielding sleeve, a stator is installed on the inner side wall of the base, an upper sleeve and a lower sleeve are respectively provided at the upper and lower ends of the stator, and the upper sleeve, the lower sleeve and the outer wall sleeve of the stator are provided with an integrally formed stator shielding sleeve; wherein, the stator shielding sleeve a covers the stator core part, and the stator shielding sleeve b covers the upper sleeve and the lower sleeve part, a gap a is provided between the stator shielding sleeve a and the rotor shielding sleeve, a gap b is provided between the stator shielding sleeve b and the rotor shielding sleeve, and the distance of the gap b is greater than the distance of the gap a;

[0006] The upper end of the impeller shaft is fitted with a lower bearing through a lower bearing seat, and guide grooves are arranged on the inner ring side walls of the lower bearing, the middle bearing and the upper bearing, a cooling water cavity concentric with the inner ring is arranged above the guide groove, and a thrust plate guide groove connected to the cooling water cavity is arranged on the extension of the cooling water cavity.

[0007] In the above invention, further, an upper liquid chamber is arranged on the upper bearing seat, a middle liquid chamber connected to the upper liquid chamber is formed between the upper sleeve and the upper stator plate, a lower liquid chamber is formed between the lower sleeve and the lower stator plate, and the middle liquid chamber is connected to the lower liquid chamber through the gap b and the gap a.

[0008] In the above invention, further, the low-pressure area of ​​the pump housing is provided with a cooling water outlet, and the cooling water outlet is connected to a circulating water pipe communicated with the upper liquid chamber.

[0009] In the above invention, further, an air release valve connected to the upper liquid chamber is arranged above the upper bearing seat.

[0010] In the above invention, further, a drain bolt is provided on the pump body.

[0011] In the above invention, further, a support bearing is mounted on the bottom of the impeller shaft.

[0012] In the above invention, further, a tensioning screw is connected between the pump housing and the pump body.

[0013] In the above invention, further, the distance of the gap a is 0.5-1.0 mm, the diameter of the stator shielding sleeve a is denoted as D, and the diameter of the stator shielding sleeve b is denoted as D1, wherein D=D1+2 mm.

[0014] The beneficial effects of the present invention are:

[0015] The diameter of the stator shielding sleeve of the present invention adopts a segmented variable diameter design. The stator shielding sleeve a covers the stator core part, and the stator shielding sleeve b covers the upper and lower shield parts. There is a gap a between the stator shielding sleeve a and the rotor shielding sleeve, and there is a gap b between the stator shielding sleeve b and the rotor shielding sleeve, and the distance of the gap b is greater than the distance of the gap a. The stator shielding sleeve adopts a variable diameter design, so that the upper and lower matching gaps of the stator shielding sleeves at both ends of the stator are increased, preventing mutual interference and friction such as movement and shaking, increasing the service life, and ensuring the efficiency of the shielded motor. Secondly, guide grooves and thrust plate guide grooves are provided on the upper, middle and lower bearings. A cooling water chamber is provided above the guide groove, which is concentric with the inner ring of the bearing and connected to the guide groove. The liquid in the cooling water chamber can flow outward through the thrust plate guide groove, thereby ensuring the lubrication of the bearing; finally, the high water pressure in the cooling water chamber can generate a continuous upward thrust on the thrust plate, reduce the axial force of the rotor, reduce the wear of the thrust plate, and extend the service life of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention;

[0017] Figure 2 for Figure 1Middle AA section view;

[0018] Figure 3 for Figure 1 Middle BB or CC section view;

[0019] Figure 4 for Figure 1 A partial enlarged view of part D in the middle;

[0020] Figure 5 is a cross-sectional view of the lower bearing of the present invention;

[0021] Figure 6 is a three-dimensional diagram of the lower bearing of the present invention;

[0022] Figure 7 This is a schematic diagram of the cooperation between the lower bearing and the thrust plate of the present invention;

[0023] Figure 8 It is a test schematic diagram of the axial force test device in the experimental example of the present invention;

[0024] Fig. 9 Graph showing the relationship between lift and axial force in the experimental example of the present invention.

[0025] In the figure, 1-base, 2-casing, 3-pump casing, 4-lower pump body, 5-upper bearing seat, 6-upper bearing, 7-middle bearing seat, 8-middle bearing, 9-motor shaft, 10-shaft link key, 11-impeller shaft, 12-rotor, 13-rotor shielding sleeve, 14-stator, 15-upper sleeve, 16-lower sleeve, 17-stator shielding sleeve, 17.1-stator shielding sleeve a, 17.2-stator shield Sleeve b, 18-gap a, 19-gap b, 20-lower bearing, 21-guide groove, 22-cooling water chamber, 23-thrust plate guide groove, 24-upper liquid chamber, 25-upper stator plate, 26-middle liquid chamber, 27-lower stator plate, 28-lower liquid chamber, 29-cooling water outlet, 30-circulating water pipe, 31-air release valve, 32-drain bolt, 33-support bearing, 34-tensioning screw. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0027] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0028] Example:

[0029] A multi-stage canned pump that can increase its service life. Figure 1 -Attached Figure 4 As shown, it includes a base 1, a casing 2, a pump casing 3, and a pump body 4 arranged from top to bottom, the top of the base 1 is equipped with an upper bearing 6 through an upper bearing seat 5, and the bottom of the base 1 is equipped with a middle bearing 8 through a middle bearing seat 7, a motor shaft 9 is installed between the upper bearing 6 and the middle bearing 8, the motor shaft 9 is constrained in a vertical state by the upper bearing 6 and the middle bearing 8, the motor shaft 9 extends downward to the inner cavity of the casing 2 and is connected to an impeller shaft 11 extending into the pump casing 3 through a shaft link key 10, a multi-stage impeller inside the pump casing 3 is installed on the impeller shaft 11, the impeller shaft 11 is concentrically arranged with the motor shaft 9, and a tensioning screw 34 is connected between the pump casing 3 and the pump body 4.

[0030] A rotor 12 is mounted on the motor shaft 9, a rotor shielding sleeve 13 is arranged on the outer wall of the rotor 12, a stator 14 is installed on the inner wall of the base 1, an upper sleeve 15 and a lower sleeve 16 are respectively arranged at the upper and lower ends of the stator 14, and the upper sleeve 15, the lower sleeve 16 and the outer wall of the stator 14 are sleeved with an integrally formed stator shielding sleeve 17; wherein, the stator shielding sleeve a17.1 covers the core part of the stator 14, and the stator shielding sleeve b17.2 covers the upper sleeve 15 and the lower sleeve 16, a gap a18 is provided between the stator shielding sleeve a17.1 and the rotor shielding sleeve 13, a gap b19 is provided between the stator shielding sleeve b17.2 and the rotor shielding sleeve 13, and the distance of the gap b19 is greater than the distance of the gap a18.

[0031] That is, in the present invention, the stator shielding sleeve 17 adopts a variable diameter design, and the diameter of the stator shielding sleeve b17.2 covering the upper stator sleeve 15 and the lower stator sleeve 16 is smaller than the stator shielding sleeve a17.1 covering the stator core 14. Preferably, the distance of the gap a17.1 is set to 0.5-1.0 mm, the diameter of the stator shielding sleeve a17.1 is recorded as D, and the diameter of the stator shielding sleeve b17.2 is recorded as D1, wherein D=D1+2 mm, that is, the distance of the gap b19 is 2 mm larger than the distance of the gap a18.

[0032] In the specific use of the present invention, since there is a gap a18 between the stator shielding sleeve a17.1 and the rotor shielding sleeve 13, the gap a18 can ensure the stable operation between the stator 14 and the rotor 12, and there is a gap b19 between the stator shielding sleeve b17.2 and the rotor shielding sleeve 13, and the distance of the gap b19 is 2mm greater than the distance of the gap a18. The stator shielding sleeve adopts a variable diameter design, so that the upper and lower matching gaps of the stator shielding sleeve b17.2 at both ends of the stator 14 are increased, and the mutual interference friction such as movement and shaking is prevented, thereby overcoming the friction between the rotor shielding sleeve and the stator shielding sleeve caused by the process accuracy of the welding port, increasing the service life, and ensuring the efficiency of the shielded motor.

[0033] Continue to refer to the attached Figure 1 As shown, the upper end of the impeller shaft 11 is provided with a lower bearing 20 through a lower bearing seat 19. The bottom of the impeller shaft 11 is provided with a support bearing 33 to enhance the rotation stability of the impeller shaft 11. Figure 5 -Attached Figure 6 As shown, the inner ring sidewalls of the lower bearing 20, the middle bearing 8 and the upper bearing 6 are all provided with guide grooves 21, and a cooling water cavity 22 concentric with the inner ring is provided above the guide groove 21, and a thrust plate guide groove 23 connected to the cooling water cavity 22 is provided outside the cooling water cavity 22. It should be noted that Figure 5 and attached Figure 6 The figure shows a schematic diagram of the structure of the lower bearing 20. The structure of the middle bearing 8 and the upper bearing 6 is the same as that of the lower bearing 20. Figure 1As shown, an upper liquid chamber 24 is provided on the upper bearing seat 5, a middle liquid chamber 26 communicating with the upper liquid chamber 24 is formed between the upper jacket 15 and the upper stator plate 25, a lower liquid chamber 28 is formed between the lower jacket 16 and the lower stator plate 27, and the middle liquid chamber 26 communicates with the lower liquid chamber 28 through the gap b19 and the gap a18. A cooling water outlet 29 is provided in the low-pressure area of ​​the pump housing 3, and a circulating water pipe 30 communicating with the upper liquid chamber 24 is connected to the cooling water outlet 29. During the operation of the shielded pump, most of the high-pressure liquid is output through the outlet of the pump body 4 under the multi-stage pressurization of the shielded pump, and a small part of the liquid in the high-pressure area of ​​the shielded pump enters the cooling water chamber 22 of the lower bearing 20 through the guide groove 21 of the lower bearing 20 and lubricates the lower bearing 20. The liquid in the cooling water chamber 22 enters the inner cavity of the casing 2 through the thrust plate guide groove 23. The liquid in the casing 2 then passes through the guide groove of the middle bearing 8, the cooling water chamber and the thrust plate guide groove to enter the lower liquid chamber 28 in turn. The liquid in the lower liquid chamber 28 then flows into the middle liquid chamber 26 through the gap b19 and the gap a18 in turn. When the liquid flows through the gap b19 and the gap a18, it can take away the heat generated by the stator 14 and the rotor 12 during operation, thereby cooling the pump motor. The liquid in the middle liquid chamber 26 enters the upper liquid chamber 24 again through the thrust plate guide groove, cooling water chamber and guide groove of the upper bearing 6. The liquid in the upper liquid chamber 24 finally flows back to the cooling outlet 29 of the low-pressure area of ​​the shielded pump through the circulating water pipe 30. It can be seen from the above process that the liquid can not only lubricate the lower bearing 20, the middle bearing 8 and the upper bearing 6 during the circulation process, but also cool the motor of the shielded pump, thereby extending the service life of the shielded pump. Secondly, further, please refer to the attached Figure 5 As shown, the high-pressure liquid entering the cooling water chamber 22 through the guide groove 21 will continuously generate an upward thrust on the thrust plate. Similarly, the circulating high-pressure water flow will also generate a continuous thrust on the middle bearing 8 above the lower bearing 20 and the thrust plate matched on the upper bearing 6. Through the superimposed axial thrust, the rotor axial force is finally reduced, and the wear of the thrust plate is also reduced, so as to achieve the effect of greatly extending the service life of the motor.

[0034] In the above embodiment, as a preference, an air release valve 31 connected to the upper liquid chamber 24 is provided above the upper bearing seat 5, and when the pressure in the upper liquid chamber 24 is abnormal, the pressure can be released through the air release valve 31. Secondly, a drain bolt 32 is provided on the pump body 4, and when the drainage is abnormal, the drain bolt 32 can be used to drain the water.

[0035] Experimental example:

[0036] Participate in the Figure 8As shown, the axial thrust test device is connected to the shielded pump rotor, and the lever and the dynamometer are used to test the axial force on the rotor when using the conventional bearing and the bearing provided by the present invention. The test data are compared in the following table and the attached Figure 8 As shown in the test results, the axial thrust is reduced by more than 2.1%, especially with the increase of head. The effect of low head is also very obvious.

[0037]

[0038] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A multi-stage canned motor pump capable of increasing service life, characterized in that: The invention comprises a base, a casing, a pump casing and a pump body which are arranged from top to bottom, an upper bearing is installed on the top of the base through an upper bearing seat, a middle bearing is installed on the bottom of the base through a middle bearing seat, a motor shaft is installed between the upper bearing and the middle bearing, the motor shaft extends downward to the inner cavity of the casing and is connected to an impeller shaft extending into the pump casing through an axis link key, the impeller shaft is arranged concentrically with the motor shaft; a rotor is sleeved on the motor shaft, a rotor shielding sleeve is arranged on the outer wall of the rotor, a stator is installed on the inner side wall of the base, an upper sleeve and a lower sleeve are respectively arranged at the upper and lower ends of the stator, and an integrally formed stator shielding sleeve is provided on the upper sleeve, the lower sleeve and the outer wall sleeve of the stator; wherein, a stator shielding sleeve a covers the stator core part, and a stator shielding sleeve b covers the upper sleeve and the lower sleeve part, a gap a is provided between the stator shielding sleeve a and the rotor shielding sleeve, a gap b is provided between the stator shielding sleeve b and the rotor shielding sleeve, and the distance of the gap b is greater than the distance of the gap a; The upper end of the impeller shaft is fitted with a lower bearing through a lower bearing seat, and guide grooves are arranged on the inner ring side walls of the lower bearing, the middle bearing and the upper bearing, and a cooling water cavity concentric with the inner ring and connected to the guide groove is arranged above the guide groove, and a thrust plate guide groove connected to the cooling water cavity is arranged on the extension of the cooling water cavity.

2. A multi-stage canned motor pump capable of increasing service life according to claim 1, characterized in that: An upper liquid chamber is provided on the upper bearing seat, a middle liquid chamber connected to the upper liquid chamber is formed between the upper sleeve and the upper stator plate, a lower liquid chamber is formed between the lower sleeve and the lower stator plate, and the middle liquid chamber is connected to the lower liquid chamber through gaps b and a.

3. A multi-stage canned motor pump capable of increasing service life according to claim 2, characterized in that: The low-pressure area of ​​the pump housing is provided with a cooling water outlet, and the cooling water outlet is connected with a circulating water pipe communicated with the upper liquid chamber.

4. A multi-stage canned motor pump capable of increasing service life according to claim 2, characterized in that: An air release valve connected with the upper liquid chamber is arranged above the upper bearing seat.

5. A multi-stage canned motor pump capable of increasing service life according to claim 1, characterized in that: A water discharge bolt is arranged on the pump body.

6. A multi-stage canned motor pump capable of increasing service life according to claim 1, characterized in that: The bottom of the impeller shaft is sleeved with a supporting bearing.

7. A multi-stage canned motor pump capable of increasing service life according to claim 1, characterized in that: A tensioning screw is connected between the pump casing and the pump body.

8. The multi-stage canned motor pump capable of increasing service life according to claim 1, characterized in that: The distance of the gap a is 0.5-1.0 mm, the diameter of the stator shielding sleeve a is denoted as D, and the diameter of the stator shielding sleeve b is denoted as D1, wherein D=D1+2 mm.

Images