Multi-stage stamping and welding type wind power generation shield pump

Abstract

The invention is suitable for the technical field of shield pumps, and provides a multistage stamping welding type wind power generation shield pump which comprises a pump part and a shield motor part. The pump part comprises a base, a pump body, a multi-stage impeller formed by stamping and welding stainless steel sheets, and a first-stage flow guide body, a middle flow guide body and a final-stage flow guide body which are matched with the multi-stage impeller; the pump part further comprises a balance disc device used for automatically balancing axial force. A balance cavity communicated with a suction low-pressure area of the pump part is formed between the balance disc and the front bearing seat, and automatic balance of axial force is achieved by adjusting an axial gap between the balance disc and the balance disc gland. The device has the advantages of high efficiency, energy conservation, low cost, no leakage, no maintenance, long service life and the like, is an ideal matching product of a wind power generation water cooling system, and is beneficial to promoting the sustainable and healthy development of the wind power industry.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shielding pumps, more particularly, to a multi-stage stamping and welding wind power shielding pump. BACKGROUND

[0002] Wind energy, as a clean and renewable energy source, has been widely used in the field of wind power generation. During the operation of a wind turbine, the gear box, generator, frequency converter and other equipment will generate a large amount of heat, which needs to be cooled by a water cooling system to ensure the reliability and stability of the wind turbine. The delivery of the circulating cooling liquid (usually a glycol water solution) depends on the circulating water pump.

[0003] Currently, there are two technical forms of circulating water pumps used in wind power cooling systems: The first one is a mechanical seal type centrifugal pump. This type of water pump usually uses a mechanical seal as the sealing method for the rotating shaft. However, the mechanical seal belongs to a dynamic seal, which is prone to wear and leakage after long-term operation and requires regular maintenance and replacement of the sealing element. Since wind turbines are often installed in remote areas such as grasslands, mountains and offshore platforms, transportation is difficult and maintenance work is extremely difficult, resulting in high maintenance costs. If the mechanical seal leaks are not discovered in time, the loss of cooling liquid will cause the cooling system to fail, the turbine to overheat and the reliability and economy of the wind power system to be severely affected. In addition, the traditional mechanical seal type centrifugal pump usually uses a shaft coupling to connect the motor and the pump body, which has a large overall structure and a long axial size. The motor usually has a cooling fan, which produces a lot of noise during operation. Some mechanical seal type centrifugal pumps use stamping and welding water power components to reduce weight, but lack effective axial force balancing structure, and the axial force generated by the impeller is completely borne by the motor rolling bearing, resulting in large bearing load and limited service life.

[0004] The second one is a shielding type centrifugal pump with cast water power components. This type of water pump integrates the pump and the motor in the same sealed housing, uses a shielding sleeve to isolate the stator and the rotor from the delivery medium, eliminates the dynamic seal structure, realizes leak-free delivery and solves the problem of easy leakage of mechanical seal type centrifugal pumps. However, the existing cast shielding pump has the following disadvantages: first, the water power components are formed by casting process, regardless of single or multi-stage structure, the wall thickness of the impeller and the guide vane is large, resulting in large pump body weight, high material cost and long production cycle; second, the surface roughness of the cast flow channel is high, the water power loss is large and the pump efficiency is low; third, the balance of the impeller axial force usually uses the method of setting balance ribs on the rear cover plate of the impeller, which consumes part of the motor power, increases the water power loss and further reduces the operating efficiency of the pump, which is not conducive to energy saving and consumption reduction.

[0005] Therefore, how to further reduce the weight of the pump body, reduce the manufacturing cost, improve the hydraulic efficiency, prolong the service life, and adapt to the special working condition requirements of the remote deployment and difficult maintenance of the wind power generation equipment under the premise of realizing the leakage-free conveying medium is a technical problem to be solved in the field. SUMMARY

[0006] In view of the deficiencies in the prior art, the purpose of the present application is to provide a multi-stage stamping and welding type wind power generation shield pump, which combines the design and manufacturing technology of stamping and welding pumps with shield pump technology, has multiple advantages such as high efficiency, energy saving, low cost, no leakage, maintenance-free, long service life, is an ideal supporting product for wind power generation water cooling systems, and helps to promote the sustainable and healthy development of the wind power industry.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions: A multi-stage stamping and welding type wind power generation shield pump, comprising a pump part and a shield motor part; the pump part comprises a base, a pump body, and a multi-stage impeller and a first-stage flow guide, an intermediate flow guide and a final-stage flow guide stamped and welded from a stainless steel sheet; the shield motor part comprises a stator assembly, a rotor assembly, a front bearing seat, a rear bearing seat, and a shaft sleeve and a thrust disc sleeved on the shaft of the rotor assembly; the pump part further comprises a balance disc device for automatically balancing the axial force; the balance disc device is arranged between the final-stage flow guide and the front bearing seat, and comprises a balance disc fixed on the shaft of the rotor assembly and a balance disc gland fixed on the front bearing seat; a balance cavity communicating with the suction low-pressure area of the pump part is formed between the balance disc and the front bearing seat, and the automatic balancing of the axial force is realized by adjusting the axial gap between the balance disc and the balance disc gland.

[0008] The present application is further provided that: a floating seal ring is arranged between the front port ring of the impeller and the first-stage flow guide, the intermediate flow guide and the final-stage flow guide; the floating seal ring is made of polytetrafluoroethylene material, and is used to form a non-contact liquid film seal with the impeller port ring during pump operation.

[0009] The present application is further provided that: the shaft sleeve and the thrust disc are made of a stainless steel base surface sprayed with WC hard alloy; the main bearing of the shield motor part is made of graphite immersed with antimony superhard material.

[0010] The present application is further provided that: the shield motor part further comprises an internal pressurized cooling circulation structure; The internal pressurized cooling circulation structure comprises a central hole and a radial hole arranged at the rear of the shaft of the rotor assembly, a secondary impeller arranged at the rear end of the rotor assembly, a liquid storage cavity arranged on the front bearing seat and a radial hole communicating with the high-pressure area of the outlet of the last-stage guide vane, and cooling lubricating liquid flows back through the liquid storage cavity, the shaft central hole, the rear cavity of the motor and the gap between the stator and the rotor shield sleeve under the driving of the secondary impeller, thereby forming a cooling circulation loop.

[0011] The application further provides that the top of the pump part is provided with an automatic exhaust valve; the automatic exhaust valve is provided with a float that rises and falls with the liquid level and an elastic pull rod connected with the float; the float is used for automatically opening the exhaust when there is gas in the pump cavity and automatically closing after the gas is exhausted; the elastic pull rod is connected with the float and cooperates with the exhaust hole; when gas is accumulated in the pump cavity, the liquid level falls, the float falls to drive the elastic pull rod to deform, and the exhaust hole is opened to exhaust; after the gas is exhausted, the liquid level rises, the float rises to reset the elastic pull rod, and the exhaust hole is closed.

[0012] The application further provides that the inner hole of the first-stage guide vane is provided with an auxiliary bearing, and the shaft of the rotor assembly is provided with an auxiliary shaft sleeve at a position corresponding to the auxiliary bearing, so that the auxiliary bearing and the auxiliary shaft sleeve provide auxiliary support for the front end of the rotor.

[0013] The application further provides that the auxiliary bearing is made of graphite impregnated with antimony superhard material, and the auxiliary shaft sleeve is made of stainless steel with a WC hard alloy sprayed on the surface.

[0014] The application further provides that the relative friction surface of the balance disc and the balance disc cover is provided with a DMC treatment layer or a vacuum diamond-like film layer.

[0015] The application further provides that the shield motor part is a three-phase asynchronous induction motor or a permanent magnet synchronous motor.

[0016] The application further provides that the front end of the shaft of the rotor assembly is provided with a spline, the impeller is connected with the shaft through the spline, and a bushing is arranged between the impellers.

[0017] The application has the following advantages: 1. The application adopts a multi-stage stamping and welding water model, and the impeller and the guide vane are formed by stamping and laser welding of stainless steel sheets with a thickness of about 1-1.5 mm. Compared with traditional cast impellers and guide vanes (with a wall thickness of about 5 mm), the amount of material is greatly reduced. According to calculation, the weight of the stamping and welding water parts is only one-third of that of the cast water parts, and the material cost is correspondingly reduced to about one-third. Under the background of full realization of on-grid parity in the wind power industry and pressure transmission of cost reduction in the whole industry chain, the structural design effectively reduces the manufacturing cost of the shield pump and improves the market competitiveness of the product.

[0018] 2、The application adopts shielding motor structure, the inner and outer walls of the motor stator are provided with stator shielding sleeves, the outer wall of the rotor is provided with a rotor shielding sleeve, the two shielding sleeves are respectively welded with the motor flange and the rotor cover plate by argon arc welding, the electromagnetic components such as the stator core, the rotor core and the winding are completely isolated from the conveying medium. The static sealing mode such as the O-shaped sealing ring is adopted between the pump body and the motor, the mechanical dynamic sealing structure of the traditional centrifugal pump is cancelled, the possibility of medium leakage is completely eliminated, it is especially suitable for the special working conditions such as remote deployment, unattended and difficult maintenance of the wind power generation equipment, the problem of cooling system failure and unit overheating failure caused by leakage is effectively avoided, and the operation reliability of the wind power generation system is greatly improved.

[0019] 3、The application adopts multi-stage impeller structure, under the condition that the total head is unchanged, the single-stage impeller head is reduced and the specific speed is improved, which is beneficial to improve the water efficiency. The impeller and the flow guide are formed by laser welding after stamping of stainless steel sheet, the welding seam is continuous, the penetration is large, the welding is firm, the flow channel surface is smooth and regular, the water loss is small, and the water efficiency is higher than that of the cast flow channel. Meanwhile, the floating sealing ring is arranged between the impeller front ring and the flow guide, the fluid dynamic pressure effect is formed in the gap during pump operation, the floating ring is floated to form the non-contact liquid film sealing, the leakage loss at the impeller ring is reduced, the volumetric efficiency is improved, the mechanical friction between the sealing ring and the impeller ring is avoided, and the good sealing effect is maintained for a long time.

[0020] 4、The application sets the balance disc device between the last-stage flow guide and the front bearing seat, the balance disc is fixed on the rotor shaft, the axial gap and the radial gap are formed between the balance disc and the balance disc cover, the front side of the balance disc communicates with the high-pressure area of the last-stage flow guide, and the rear side balance cavity communicates with the low-pressure area of the first-stage impeller inlet through the radial hole and the shaft hole. When the axial force of the rotor changes, the upward axial force generated by the balance disc can automatically balance the downward axial force of the multi-stage impeller and the self-weight of the rotor assembly through the self-adaptive adjustment of the axial gap, so that the rotor is in a suspended state between the upper and lower bearings. The axial force automatic balancing mode does not need to consume additional motor power, effectively reduces the load of the bearing, the shaft sleeve and the thrust disc, reduces the mechanical friction, and significantly improves the service life of the vulnerable parts.

[0021] 5、The main bearing and the auxiliary bearing adopt graphite impregnated antimony superhard material, the shaft sleeve, the thrust disc and the auxiliary shaft sleeve adopt stainless steel surface sprayed WC hard alloy, which has high hardness and good wear resistance. According to the continuous endurance test, the service life can reach more than 6 years, which meets the long-period operation and maintenance-free use requirements of the wind power generation equipment. The auxiliary bearing and the auxiliary shaft sleeve arranged in the inner hole of the first-stage flow guide provide auxiliary support for the slender shaft of the front end of the rotor, increase the rigidity of the rotor, and ensure the stability of the pump operation.

[0022] 6, The application adopts internal pressurized cooling circulation structure, uses conveying medium as cooling lubricating liquid, sets central hole and auxiliary impeller at the rear of rotor shaft, sets liquid storage cavity and radial channel at front bearing seat. In working, high pressure liquid enters liquid storage cavity, then flows to auxiliary impeller through shaft central hole to increase pressure, enters motor rear cavity, then returns to motor front cavity through gap between stator and rotor shield sleeve to complete circulation. The circulation mode effectively cools and lubricates motor and bearing, does not need external cooling pipeline, has compact structure and guarantees long-term operation reliability of motor.

[0023] 7, The application sets automatic exhaust valve at the top of pump, and the valve is provided with float and elastic pull rod. When filling pump or gas gathers in pump cavity, liquid level drops, float falls to drive pull rod to deform and open exhaust hole, and gas is automatically exhausted; after gas is exhausted, liquid level rises, float rises to reset pull rod to close exhaust hole. The automatic exhaust device does not need manual operation, avoids problems such as gas binding and vibration caused by gas storage in pump cavity, and guarantees safe and reliable start and operation of pump. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a sectional view of a multi-stage stamping and welding type wind power generation shield pump of the application.

[0025] Figure 2 It is a structural schematic view of pump body of the application.

[0026] Figure 3 It is a structural schematic view of multi-stage impeller of the application.

[0027] Figure 4 It is a structural schematic view of first-stage flow guide of the application.

[0028] Figure 5 It is a structural schematic view of intermediate flow guide of the application.

[0029] Figure 6 It is a structural schematic view of intermediate flow guide in front view angle of the application.

[0030] Figure 7 It is a structural schematic view of front bearing seat of the application.

[0031] Figure 8 It is a structural schematic view of balance disc of the application.

[0032] Figure 9 It is a structural schematic view of rotor assembly of the application.

[0033] In the figure: 1, base; 2, pump body; 3, first stage guide vane; 4, multi-stage impeller; 5, intermediate guide vane; 6, last stage guide vane; 7, balance disc cover; 8, balance disc; 9, pump jacket; 10, O-shaped sealing ring; 11, front bearing seat; 12, shaft sleeve; 13, thrust disc; 14, main bearing; 15, stator assembly; 16, rotor assembly; 17, terminal box assembly; 18, automatic exhaust valve; 19, rear bearing seat; 20, rectangular sealing gasket; 21, shaft sleeve thrust disc key; 22, auxiliary impeller; 23, stator shield; 24, rotor shield; 25, screw; 26, floating sealing ring; 27, bushing; 28, auxiliary shaft sleeve; 29, auxiliary bearing. DETAILED DESCRIPTION

[0034] It should be noted that the embodiments and features in the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0035] It should be noted that, unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0036] In the present application, unless otherwise specified, the orientation such as "up, down" is generally with respect to the direction shown in the drawings, or with respect to the vertical, perpendicular or gravity direction; similarly, for the convenience of understanding and description, "left, right" is generally with respect to the left and right shown in the drawings; "inner, outer" refers to the inner and outer with respect to the contour of each component itself, but the above orientation words are not used to limit the present application.

[0037] Embodiment, please refer to Figures 1-9 The present application provides the following technical solutions: A multi-stage stamping and welding type wind power generation shield pump, specifically the present application adopts a multi-stage stamping and welding type hydraulic shield type centrifugal pump. The product structure comprises a stamping and welding hydraulic part and a shield motor part.

[0038] Structure description: the pump part is composed of base 1, pump body 2, first stage guide vane 3, impeller 4, intermediate guide vane 5, last stage guide vane 6, balance disc cover 7, balance disc 8, pump jacket 9, O-shaped sealing ring 10 and the like; the shield motor part is composed of front bearing seat 11, stator assembly 15 (including stator shield 23), rotor assembly 16 (rotor shield 24), shaft sleeve 12, thrust disc 13, bearing 14, rear bearing seat 19, terminal box assembly 17.

[0039] The shaft sleeve thrust disc is fixed on the rotor shaft by key 21, the rotor assembly 16 is supported by front and rear bearings 14, the front and rear bearings 14 are fastened in front and rear bearing seats respectively, the front bearing seat 11 is connected with the front flange of the motor by hexagonal bolts, the rear bearing seat 19 is connected with the rear flange of the motor by hexagonal bolts, and the middle is sealed by a rectangular sealing gasket 20. The front and rear shaft sleeves 12 and the thrust disc 13 are fixed on the rotor assembly 16 by keys. During operation, the rotor rotates at high speed under the driving of electromagnetic force. The inner diameter of the bearing rubs with the outer diameter of the sleeve to limit the radial runout of the rotor, and the end face of the bearing rubs with the thrust disc to limit the axial displacement of the rotor.

[0040] The main bearing 14 is made of graphite immersed antimony superhard material, and the shaft sleeve 12 and the thrust disc 13 are made of stainless steel surface sprayed with WC hard alloy, which has high hardness and good wear resistance, and can ensure a long service life of the wind power shielding pump.

[0041] The auxiliary bearing 26 is arranged in the inner hole of the first-stage flow guide, and the material is also graphite immersed antimony superhard. The corresponding position of the rotor shaft is provided with an auxiliary sleeve 25, and the material is also stainless steel surface sprayed with WC hard alloy. The auxiliary bearing and the auxiliary sleeve provide auxiliary support for the slender shaft of the front end of the rotor, increase the stiffness of the rotor, and ensure the stable operation of the pump.

[0042] The inner diameter of the stator assembly 15 and the outer diameter of the rotor assembly 16 are respectively provided with a stator shielding sleeve 23 and a rotor shielding sleeve 24, which are respectively welded with the front and rear flanges of the motor and the front and rear cover plates of the rotor by argon arc welding. The conveying medium is separated from the electromagnetic material, which protects the motor. The motor type is a three-phase asynchronous induction motor, and a permanent magnet synchronous motor can also be used to meet the different use requirements of customers. Since the shielding motor is used, the mechanical seal of the ordinary motor is cancelled, which can ensure that the conveying medium is absolutely leakproof, and greatly improves the safety and reliability of the product use.

[0043] The front end of the rotor shaft is processed into a spline groove form, and each stage of the stamped and welded multi-stage impeller 4 is installed and connected with the rotor shaft in the form of spline groove, which can ensure the assembly accuracy of the thin-walled multi-stage impeller 4. A bushing 27 is arranged between each stage of the multi-stage impeller 4 to facilitate the adjustment of the gap between the impellers.

[0044] The front bearing seat 11 is connected with the front flange of the motor by hexagonal screws, and the front bearing seat 11 is provided with an axial force automatic balancing structure on the front side: a balance disc 8 and a balance disc cover 7, which can automatically balance the axial force of the pump. The balance disc cover 7 is connected with the front bearing seat 11 by hexagonal screws, the front end face is uniformly processed with four round holes, four rubber cylinders are inserted, and each stage of the flow guide is buckled together, The pump body 2 and the motor front flange are sealed by radial O-rings 10. The motor front flange and the pump base 1 are connected by four through rods 25, which are tightened, and the pump body 2 and the pump jacket 9 are also fixed, and the inner guide vanes are also compressed at the same time. At this time, the four rubber cylinders on the balance disc cover 7 are pressed on the end surface of the last guide vane 6, and the elasticity thereof reserves the compression amount, coordinates the axial size of each guide vane, ensures the compression and sealing between each guide vane, and avoids the interference with the axial size of the external pump jacket.

[0045] Punched and welded hydraulic components: the multi-stage impeller 4 and guide vanes (5 stages in the present product) ensure that the total head is unchanged, the single-stage impeller head is reduced, the specific speed is increased, and the hydraulic efficiency of the whole pump is improved. The impeller and the guide vane are punched by stainless steel sheet and welded by special tooling. The weld is exquisite, continuous, deep, reliable, the surface of the flow channel is regular, the hydraulic efficiency is high. The stainless steel sheet is very thin, about 1-1.5 mm, and the wall thickness of the cast impeller and guide vane is about 5 mm, so the weight is greatly reduced. The weight of the punched and welded hydraulic components is only one third of the cast hydraulic components, and the material cost is also one third of the cast hydraulic components. The material cost is greatly reduced.

[0046] Floating impeller ring seal: the floating seal ring 26 is used between the impeller front ring and the guide vane to reduce the leakage at the impeller ring and improve the pump volumetric efficiency. The floating seal ring 26 is limited on each guide vane by the ring cover. The floating ring seal is realized by the great hydraulic resistance generated in the narrow gap between the seal ring and the impeller ring. The principle of the floating ring seal is that the liquid film formed between the floating ring and the impeller ring by the liquid with pressure generated by the rotation of the impeller produces throttling and pressure reduction, and prevents the leakage of high pressure at the impeller outlet to the low pressure at the impeller inlet. When the impeller does not rotate, the inner wall of the seal ring will be attached to the impeller ring due to the gravity of the seal ring, forming an eccentric gap. When the impeller rotates, the surface of the impeller ring brings the seal liquid into the eccentric gap, and the fluid dynamic pressure effect is generated in the gap, so that the floating seal ring floats up, and the inner wall of the ring is separated from the shaft surface to become a non-contact state. The floating property enables the floating seal ring to have the automatic centering function, which can adapt to the shaft and the impeller deflection, avoid the friction between the impeller ring and the floating seal ring, and make the floating seal ring and the impeller ring locally larger gap into a uniform small annular gap, enhance the resistance generated by throttling, and improve the sealing performance. The material of the floating seal ring is polytetrafluoroethylene, and the automatic centering function of the floating seal ring makes the floating seal ring and the impeller ring not in contact with each other to produce wear, and long-term small gap is maintained to ensure the sealing effect.

[0047] The automatic balance mode of the balance disc 8 axial force: the stamping and welding impeller has no rear seal ring. For the multi-stage stamping and welding shield pump with vertical structure, each impeller generates downward axial force. In addition to the weight of the rotating component, the axial force aggravates the wear of the bearing sleeve thrust disc. The patent product adopts an automatic axial force balance mode of the balance disc type.

[0048] A balance disc 8 is arranged between the last-stage flow guide 6 and the front bearing seat 11, and a balance disc cover 7 is arranged between the balance disc 8 and the last-stage flow guide 6. The balance disc 8 is fixed on the rotor shaft by a key. A balance cavity is formed between the balance disc 8 and the front bearing seat 11. Radial holes are opened on the balance disc hub, and corresponding radial holes are opened on the rotor shaft. The front end of the rotor shaft has a central hole. The balance cavity is communicated with the low-pressure end of the inlet of the first-stage impeller through the radial small holes and the shaft central hole. The front end surface of the balance disc 8 and the cover form an axial gap G1, and the outer diameter of the balance disc 8 and the inner diameter of the cavity of the front bearing seat 11 form a radial gap G2. The front side of the balance disc 8 is communicated with the high-pressure area of the last-stage flow guide 6, and the rear side of the balance disc 8 is communicated with the low-pressure area of the suction inlet of the first-stage impeller. Through the axial gap G1 and the radial gap G2, the pressure of the balance cavity is reduced, and the axial force on the balance disc is upward, which can balance the downward axial force of the multi-stage impeller and the downward axial force generated by the weight of the rotor assembly.

[0049] Due to the existence of the axial gap G1, the rotor axial force can be automatically balanced. When the rotor axial force is downward, the rotor assembly 16 moves downward, the axial gap G1 decreases, the leakage of the liquid from the high-pressure cavity at the front end of the balance disc 8 to the low-pressure cavity of the balance disc 8 decreases, the upward axial force of the balance disc increases, and the rotor assembly moves upward. When the rotor assembly moves upward, the axial gap G1 increases, the leakage of the liquid from the high-pressure cavity at the front end of the balance disc 8 to the low-pressure cavity of the balance disc 8 increases, the upward axial force of the balance disc decreases, and the rotor assembly moves downward. The rotor assembly is automatically balanced, and the rotor assembly is in a suspended state between the upper and lower bearings, which greatly reduces the wear of the vulnerable parts of the bearing sleeve 13 thrust disc 14, and improves the service life of the stamping and welding shield pump.

[0050] The balance disc cover 7 and the balance disc 8 are subjected to DMC treatment on the opposite surfaces, and the surfaces are vacuum plated with a kind of diamond film to improve the surface hardness, avoid the engagement of the balance disc and the cover due to the wear of the contact surface, and improve the use reliability of the product.

[0051] Shielded motor cooling cycle mode: shielded motor and bearing shaft sleeve thrust plate wear parts need cooling and lubrication, the patent product adopts an internal pressurized cooling cycle mode, using its own conveying medium as the cooling and lubrication liquid. A center hole is opened in the rear half of the rotor shaft, which is not communicated with the center hole in the front half. A vice impeller is arranged at the rear side of the rotor core. The vice impeller is provided with four radial holes on the shaft, which are communicated with the shaft center hole. A cooling and lubricating liquid storage cavity is further arranged between the bearing cavity of the front bearing seat and the axial force balance cavity. The storage cavity is provided with four radial holes outwardly communicated with the high-pressure area of the outlet of the last guide vane. Two radial holes are arranged on the rotor shaft and the sleeve in a relative position and communicated with the shaft center hole.

[0052] During operation, the high-pressure liquid enters the storage cavity from the radial hole of the front bearing seat 11, and then enters the shaft center hole from the radial hole on the shaft. The liquid flows to the rear vice impeller 22 through the center hole, is pressurized by the vice impeller 22, and then flows back to the front cavity of the motor from the rear cavity of the motor through the gap between the stator and the rotor shield sleeve. The liquid returns to the high-pressure area from the radial rectangular slot between the front bearing seat 11 and the front flange, and completes a cycle. This part of the circulating liquid plays a role in cooling the motor and lubricating the bearing.

[0053] Liquid conveying working mode: the conveying medium enters from the inlet of the pump body 02, is pressurized by the impellers at each stage, and is guided by the guide vanes at each stage to change the radial flow into axial flow. After the last guide vane, the liquid enters the gap between the pump jacket and the guide vanes at each stage, which is communicated with the outlet of the pump body. The liquid flows out of the pump outlet, achieving the effect of conveying liquid to the water cooling system of the wind turbine generator set. The balance disc structure plays a role in automatically balancing the axial force, reducing the abnormal wear of the bearing shaft sleeve thrust plate, and improving the service life of the pump. The internal pressurized cooling cycle mode ensures the cooling and lubrication of the motor and the wear parts, and improves the service life of the motor. The complete static seal of the pump without dynamic seal structure ensures that the pump is absolutely leakproof, improving the safety and reliability of the product.

[0054] Automatic exhaust mode: the automatic exhaust valve 18 is arranged at the top of the pump. Before filling the pump and starting, the air or medium in the pump cavity can be automatically exhausted due to the generation of steam. The working principle is that a float is arranged in the valve body of the exhaust valve. The float can float up and down with the liquid level at the top of the pump. When the gas accumulates, the liquid level decreases, the float descends, the elastic pull rod is driven to bend, the exhaust hole is opened, and the gas is exhausted. After the gas is exhausted, the liquid level rises, the float also rises, the pull rod is flattened under the action of the spring, the exhaust hole is closed, and the whole pump is in a sealed state. The automatic exhaust device can automatically exhaust the gas in the pump cavity and automatically close after the gas is exhausted. It ensures that the pump can operate safely and reliably.

[0055] Obviously, the above-described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0056] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. Furthermore, it is to be understood that the term "comprising" and / or "including" when used in this specification, specifies the presence of stated features, steps, operations, devices, components and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components and / or combinations thereof.

[0057] It is to be noted that the terms "first", "second", and the like, used in the specification and in the claims are intended to distinguish between similar objects, but are not necessarily used to describe a serial or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in other sequences than those described or otherwise illustrated herein.

[0058] The preferred embodiments of the application are described above in detail. The application is not limited to the embodiments described above, but can be modified and changed by any person skilled in the art without departing from the principles of the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.

[0059] The preferred embodiments of the application are described above in detail. The application is not limited to the embodiments described above, but can be modified and changed by any person skilled in the art without departing from the principles of the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application. The preferred embodiments of the application are described above in detail. The application is not limited to the embodiments described above, but can be modified and changed by any person skilled in the art without departing from the principles of the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A multi-stage stamped and welded wind turbine canned motor pump, comprising a pump section and a canned motor section; characterized in that: The pump part includes a base (1), a pump body (2), a multi-stage impeller (4) made of stainless steel sheet by stamping and welding, and a first-stage guide fluid (3), an intermediate guide fluid (5) and a final-stage guide fluid (6) that cooperate with the multi-stage impeller (4). The shielded motor part includes a stator assembly (15), a rotor assembly (16), a front bearing housing (11), a rear bearing housing (19), a bushing (12) and a thrust disk (13) sleeved on the shaft of the rotor assembly (16). The pump section also includes a balance disc device for automatically balancing axial forces; the balance disc device is disposed between the final stage guide fluid (6) and the front bearing housing (11), and includes a balance disc (8) fixed on the shaft of the rotor assembly (16) and a balance disc cover (7) fixed on the front bearing housing (11); the balance disc (8) and the front bearing housing (11) form a balance chamber communicating with the suction low-pressure area of ​​the pump section, and the automatic balancing of axial forces is achieved by adjusting the axial gap between the balance disc (8) and the balance disc cover (7).

2. The multi-stage stamped and welded wind power generation shielded pump according to claim 1, characterized in that: A floating sealing ring (26) is provided between the front inlet ring of the impeller (4) and the first-stage guide fluid (3), the intermediate guide fluid (5) and the final-stage guide fluid (6); the floating sealing ring (26) is made of polytetrafluoroethylene material and is used to form a non-contact liquid film seal with the impeller inlet ring when the pump is running.

3. The multi-stage stamped and welded wind power generation shielded pump according to claim 2, characterized in that: The bushing (12) and thrust disk (13) are made of stainless steel substrate with WC hard alloy sprayed on the surface; the main bearing (14) of the shielded motor part is made of graphite impregnated antimony superhard material.

4. A multi-stage stamped and welded wind power generation shielded pump according to claim 3, characterized in that: The shielded motor section also includes an internal pressurized cooling circulation structure; The internal pressurized cooling cycle structure includes: The central hole and radial hole are provided at the rear of the shaft of the rotor assembly (16); A secondary impeller (22) is disposed at the rear end of the rotor assembly (16). The liquid storage cavity and the radial hole connecting the outlet high pressure zone of the final stage guide fluid (6) are provided on the front bearing housing (11); Driven by the secondary impeller (22), the cooling lubricant flows sequentially through the liquid storage chamber, the shaft center hole, the motor rear chamber, and the gap between the stator and rotor shields before returning to form a cooling circulation loop.

5. A multi-stage stamped and welded wind power generation shielded pump according to claim 4, characterized in that: The top of the pump section is provided with an automatic vent valve (18); the automatic vent valve (18) is provided with a float that rises and falls with the liquid level and an elastic rod connected to the float; the float is used to automatically open to vent when there is gas in the pump chamber and to automatically close after the gas is exhausted; the elastic rod is connected to the float and cooperates with the vent hole. When gas accumulates in the pump chamber, the liquid level drops, the float falls and causes the elastic rod to deform, opening the vent to release gas; when the gas is exhausted, the liquid level rises, the float rises and causes the elastic rod to return to its original position, closing the vent.

6. A multi-stage stamped and welded wind power generation shielded pump according to claim 5, characterized in that: The inner hole of the primary guide fluid (3) is provided with an auxiliary bearing (26); the rotor assembly (16) is provided with an auxiliary bushing (25) at a position corresponding to the auxiliary bearing (26), and the auxiliary bearing (26) and the auxiliary bushing (25) provide auxiliary support for the front end of the rotor.

7. A multi-stage stamped and welded wind power generation shielded pump according to claim 6, characterized in that: The auxiliary bearing (26) is made of graphite impregnated with antimony superhard material, and the auxiliary bushing (25) is made of stainless steel with WC hard alloy sprayed on the surface.

8. A multi-stage stamped and welded wind power generation shielded pump according to claim 7, characterized in that: The relative friction surfaces of the balance disc (8) and the balance disc cover (7) are provided with a DMC treatment layer or a vacuum-plated diamond-like film layer.

9. A multi-stage stamped and welded wind power generation shielded pump according to claim 8, characterized in that: The shielded motor section is a three-phase asynchronous induction motor or a permanent magnet synchronous motor.

10. A multi-stage stamped and welded wind power generation shielded pump according to claim 9, characterized in that: The rotor assembly (16) has a spline at the front end of the shaft, the impeller (4) is connected to the shaft through the spline, and bushings (27) are provided between each stage of the impeller.

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