Limiting device for preventing rotor of boiler feed pump from moving

Abstract

The invention relates to the technical field of power pumps, in particular to a limiting device for preventing a rotor of a boiler feed pump from moving. When the boiler feed pump is started, the elastic piece pushes the rotor to enable a gap to be formed between the balance disc and the balance seat sleeve, and when the shaft drives the rotor to rotate at a low speed, the elastic piece pushes the rotor to enable the balance disc and the balance seat sleeve to rotate at a low speed. When the rotating speed of the rotor rises and the generated axial force is larger than the elastic force applied by the elastic piece, the balance disc moves, redundant axial force is counteracted through the pressure difference between the two sides of the balance disc, and at the moment, pressure between the balance disc and the balance seat sleeve is generated. Therefore, the balance disc is not contacted with the balance seat sleeve, and the possibility of abrasion of the balance disc is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power pumps, in particular to a limiting device for preventing rotor movement of a boiler feed pump. BACKGROUND

[0002] The boiler feed pump, as the main pump of a thermal power plant, transports medium at a temperature of 158 DEG C and a lift of 2000 meters, and needs to be operated for a long time without interruption for 24 hours. The structure of the boiler feed pump is a horizontal sectional multi-stage centrifugal pump, and an axial force is balanced by a balance disc.

[0003] In the related art, the boiler feed pump includes a rotor and a protective casing for the rotor, and the rotor is composed of a shaft, an impeller, a balance disc, a throttling sleeve and other main parts. When the boiler feed pump is working, a large pressure difference is generated at both ends of the boiler feed pump, an axial force is generated, the rotor is driven to move, the balance disc is offset, and the axial thrust generated by the pressure difference of the gas on both sides of the balance disc is used to offset the axial force of the rotor. When the boiler feed pump is frequently started and stopped, the rotor will move under the driving of the axial force, and at the same time, the balance disc will also move frequently, which will cause the balance disc and the balance seat sleeve to contact each other, so that the balance disc is abraded, the service life of the balance disc is reduced, the balance disc needs to be replaced frequently, time and effort are wasted, the normal operation of the power plant is affected, and thus great economic losses are caused. SUMMARY

[0004] The present application aims at solving the problems of the prior art, and provides a limiting device for preventing rotor movement of a boiler feed pump, which reduces the possibility of abrasion of the balance disc.

[0005] To achieve the above-mentioned purpose, the present application provides a limiting device for preventing rotor movement of a boiler feed pump, which comprises an extension shaft integrally connected with a shaft of the boiler feed pump, a connecting sleeve fixedly connected to the casing, a compressed elastic member fixed to the side of the connecting sleeve away from the casing, a force receiving member fixedly connected to the extension shaft and receiving the elastic force of the compressed elastic member, and the end of the compressed elastic member away from the connecting sleeve abuts against the force receiving member, and the elastic member applies an elastic force in the opposite direction of the axial force generated by the boiler feed pump to the force receiving member.

[0006] Preferably, the extension shaft comprises a first connecting section, a second connecting section and a third connecting section coaxially integrated, the shaft diameters of the first connecting section, the second connecting section and the third connecting section decrease in sequence and are away from the boiler feed pump in sequence, the force receiving member is a force bearing, the inner ring of the force bearing abuts against the second connecting section, the third connecting section is threadedly connected with a fixing nut, the fixing nut abuts against the inner ring side wall of the force bearing, and the elastic member acts on the outer ring of the force bearing.

[0007] Preferably, the outer ring of the load bearing is provided with a bearing sleeve for fixing the outer ring of the load bearing, the bearing sleeve abutting against the circumferential wall of the outer ring of the load bearing and the side of the outer ring of the load bearing close to the elastic member, and the elastic member abutting against the side of the bearing sleeve away from the load bearing.

[0008] Preferably, the connecting sleeve is threadedly connected with a fastening screw, and the fastening screw abuts against the side of the bearing sleeve away from the load bearing.

[0009] Preferably, the second connecting section is provided with an adjusting ring, one side of the adjusting ring abutting against the first connecting section, and the side of the adjusting ring away from the first connecting section abutting against the inner ring of the load bearing.

[0010] Preferably, the side of the connecting sleeve away from the boiler feed water pump is provided with a bearing end cover, and the connecting sleeve and the bearing end cover are provided with a connecting assembly for fixing the connecting sleeve and the bearing end cover.

[0011] Preferably, the connecting assembly comprises a double-headed screw and a locking nut, the double-headed screw penetrating the bearing end cover and the connecting sleeve, the locking nut abutting against the side of the bearing end cover away from the connecting sleeve, the locking nut being threadedly connected with the double-headed screw, and the end of the double-headed screw away from the locking nut being threadedly connected with the casing of the boiler feed water pump.

[0012] Preferably, the side of the bearing end cover away from the connecting sleeve is provided with a cooling cavity for passing cold water, the bearing end cover is provided with a water passing hole communicating with the cooling cavity, and the side of the bearing end cover away from the connecting sleeve is provided with a sealing cover for sealing the cooling cavity.

[0013] Preferably, the cooling cavity is provided with a plurality of heat dissipation plates for increasing the heat dissipation area.

[0014] Compared with the prior art, the technical scheme has the beneficial effects that the elastic member applies elastic force to the force bearing, the force bearing transmits the force received to the extension shaft, the elastic force is applied to the shaft of the boiler feed water pump in the direction opposite to the axial force direction, when the boiler feed water pump is not started, the elastic member pushes the rotor, so that the gap is generated between the balance disc and the balance seat, when the shaft drives the rotor to run at low speed, the axial force generated is smaller than the elastic force applied by the elastic member, the elastic force can offset the axial force, the shaft will not move, when the rotating speed of the rotor rises, the axial force generated is greater than the elastic force applied by the elastic member, the balance disc moves, and the pressure difference on both sides of the balance disc is used to offset the excessive axial force, at this time, the pressure between the balance disc and the balance seat has been generated, so that the balance disc and the balance seat will not contact, and the possibility of wear of the balance disc is reduced; the water hole and the cooling cavity are arranged on the bearing end cover, so that the cold water is conveniently introduced into the cooling cavity during the working process, the heat generated by the force bearing is taken away, the heat dissipation effect is improved, and the service life of the force bearing is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0015] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments thereof, read in conjunction with the accompanying drawings: Figure 1 The overall structure of the anti-runout limiting device for the rotor of the boiler feed water pump of the present application; Figure 2 The overall sectional view of the anti-runout limiting device for the rotor of the boiler feed water pump of the present application; In the figure: 1, extension shaft; 101, first connecting section; 102, second connecting section; 103, third connecting section; 2, connecting sleeve; 3, elastic member; 4, force receiving member; 41, force bearing; 5, fixed nut; 6, adjusting ring; 7, bearing sleeve; 8, elastic baffle ring; 9, fastening screw; 10, bearing end cover; 11, O-ring; 12, connecting assembly; 121, double-headed screw rod; 122, locking nut; 13, cooling cavity; 14, water hole; 15, sealing cover; 16, heat dissipation plate. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be described and discussed clearly and completely in combination with the drawings of the present application. Obviously, only some examples of the present application are described here, and not all examples. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0017] It should be understood that when an element, or components, is referred to as being "on" another element, or components, it can be directly on another element or intervening elements can also be present. In addition, it should be understood that when an element or layer is referred to as being "connected", "attached" or "coupled" to another element or layer, it can be directly connected, attached or coupled to the other element or layer, or intervening elements can be present. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0019] Referring to Figure 1 and Figure 2 The embodiment provides a boiler feed pump rotor anti-channeling limiting device, which comprises an extension shaft 1 connected with a shaft of a boiler feed pump and a connecting sleeve 2 fixedly connected with a protective shell of the boiler feed pump, and the extension shaft 1 is located in the interior of the connecting sleeve 2. The inner wall of the side of the connecting sleeve 2 away from the protective shell of the boiler feed pump is annularly and uniformly abutted with four elastic members 3 in a compressed state. In the embodiment, the elastic members 3 are selected to be springs, and the elastic force generated by the springs is easy to control.

[0020] The extension shaft 1 is fixedly connected with a stress member 4, the elastic force generated by the elastic members 3 acts on the stress member 4 and is transmitted to the extension shaft 1, the direction of the elastic force is opposite to the axial force generated by the rotor of the boiler feed pump, the extension shaft 1 can push the rotor before the boiler feed pump is started, a gap is generated between the balance disc and the balance seat sleeve, the instantaneous abrasion between the balance disc and the balance seat is reduced when the boiler feed pump is started, the moving amplitude of the balance disc is reduced when the rotor speed of the boiler feed pump is changed, and the abrasion probability between the balance disc and the balance seat sleeve is reduced.

[0021] The extension shaft 1 comprises a first connecting section 101, a second connecting section 102 and a third connecting section 103 which are coaxial and integrated, the shaft diameters of the first connecting section 101, the second connecting section 102 and the third connecting section 103 are sequentially reduced and sequentially away from the boiler feed pump, and the third connecting section 103 is formed with threads.

[0022] The force receiving part 4 is a force receiving bearing 41, and the force receiving bearing 41 is in interference fit with the second connecting section 102, so that the two can rotate coaxially; the third connecting section 103 is threadedly connected with a fixing nut 5, and the fixing nut 5 abuts against the inner ring side wall of the force receiving bearing 41; the second connecting section 102 is sleeved with an adjusting ring 6, one end of the adjusting ring 6 abuts against the step formed by the first connecting section 101 and the second connecting section 102, and the other end of the adjusting ring 6 abuts against the inner ring of the force receiving bearing 41 away from the lock nut 122, and by replacing different adjusting rings 6, the installation position of the force receiving bearing 41 on the second connecting section 102 can be adjusted, so as to control the compression amount of the elastic part 3.

[0023] In the embodiment, the force receiving bearing 41 is an angular contact ball bearing, and two angular contact ball bearings are selected to abut against each other, the angular contact ball bearing can bear radial load and axial load at the same time, and the force receiving effect is good.

[0024] The outer ring of the force receiving bearing 41 is provided with a bearing sleeve 7 for protecting the force receiving bearing 41, the inner wall of the bearing sleeve 7 abuts against the peripheral wall of the outer ring of the force receiving bearing 41, and the side of the outer ring of the force receiving bearing 41 close to the elastic part 3 abuts against the step formed by the bearing sleeve 7; the side wall of the bearing sleeve 7 away from the force receiving bearing 41 abuts against the elastic part 3, so as to transmit the elastic force of the elastic part 3 to the force receiving bearing 41 and the extension shaft 1; the bearing sleeve 7 is nested with an elastic retainer 8, and the elastic retainer 8 abuts against the side of the outer ring of the force receiving bearing 41 away from the elastic part 3, so as to further increase the fixing effect of the force receiving bearing 41.

[0025] The connecting sleeve 2 is threadedly connected with a fastening screw 9, one end of the fastening screw 9 abuts against the outer peripheral wall of the bearing sleeve 7, so as to fasten the bearing sleeve 7 and reduce the possibility of rotation of the bearing sleeve 7.

[0026] The end of the connecting sleeve 2 away from the boiler feed water pump is fixedly connected with a bearing end cover 10 for sealing the force receiving bearing 41, the outer peripheral wall of the bearing end cover 10 abuts against the inner wall of the connecting sleeve 2 to form a seal, and the bearing end cover 10 is sleeved with an O-ring 11 on the outer side wall abutting against the connecting sleeve 2, so as to increase the sealing effect of the bearing end cover 10 and the connecting sleeve 2. The connecting sleeve 2 is provided with a connecting assembly 12, the connecting assembly 12 comprises a double-headed screw 121 and a lock nut 122, the double-headed screw 121 penetrates through the bearing end cover 10 and the connecting sleeve 2, the lock nut 122 is threadedly connected to one end of the double-headed screw 121, and the lock nut 122 abuts against the side of the bearing end cover 10 away from the connecting sleeve 2, so as to fix the bearing end cover 10 on the connecting sleeve 2; the other end of the double-headed screw 121 away from the lock nut 122 penetrates out of the connecting sleeve 2, and is used for threadedly connecting with the casing of the boiler feed water pump, so as to fix the connecting sleeve 2 on the casing of the boiler feed water pump.

[0027] Referring to Figure 2The bearing end cover 10 is provided with a cooling cavity 13 on the side away from the connecting sleeve 2, two water passing holes 14 are provided on the circumferential side wall of the bearing end cover 10 and communicated with the cooling cavity 13, and a sealing cover 15 is bolted on the side wall of the bearing end cover 10 away from the connecting sleeve 2 to seal the cooling cavity 13; when the boiler feed water pump is working, the two water passing holes 14 are communicated with water pipes and used as water inlets and outlets respectively, cold water is passed into the cooling cavity 13 to take away the heat generated by the stressed bearing 41 during working process and improve the service life of the stressed bearing 41. The bearing end cover 10 is integrally connected with a plurality of parallel heat dissipation plates 16 in the cooling cavity 13 to increase the contact area of the bearing end cover 10 with cold water and further improve the heat dissipation effect on the bearing.

[0028] The implementation principle of the anti-movement limiting device for the rotor of the boiler feed water pump is that the elastic member 3 applies elastic force to the stressed bearing 41, the stressed bearing 41 transmits the received force to the extension shaft 1, the elastic force is applied to the shaft of the boiler feed water pump in the direction opposite to the axial force, when the boiler feed water pump is not started, the elastic member 3 pushes the rotor to make the balance disc and the balance seat sleeve have a gap, when the shaft drives the rotor to rotate at low speed, the generated axial force is smaller than the elastic force applied by the elastic member 3, the elastic force can offset the axial force, and the shaft will not move, when the rotating speed of the rotor rises, the generated axial force is greater than the elastic force applied by the elastic member 3, the balance disc moves and offsets the excessive axial force by using the pressure difference on both sides, at this time, the elastic member 3 shares part of the axial force and reduces the moving range of the balance disc, thereby reducing the probability of grinding of the balance disc.

[0029] The specific embodiments of the application are described above. It should be understood that the application is not limited to the above specific embodiments, and one or more of the above embodiments can be combined to form a combined embodiment, and those skilled in the art can make various changes or modifications or combinations within the scope of the claims, which does not affect the essential content of the application. In the case of no conflict, the embodiments of the application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A limiting device for preventing rotor movement of a boiler feedwater pump, characterized in that: The device includes an extension shaft integrally connected to the shaft of a boiler feedwater pump. A connecting sleeve is fixedly connected to the housing. A compressible elastic element is fixedly attached to the connecting sleeve on the side away from the housing. A force-bearing element that transmits the elastic force of the elastic element is fixedly connected to the extension shaft. The end of the compressible elastic element away from the connecting sleeve abuts against the force-bearing element. The elastic element applies an elastic force to the force-bearing element in the opposite direction to the axial force generated by the boiler feedwater pump.

2. The limiting device for preventing rotor movement of a boiler feedwater pump according to claim 1, characterized in that: The extension shaft includes a first connecting section, a second connecting section, and a third connecting section that are integrally coaxial. The shaft diameters of the first connecting section, the second connecting section, and the third connecting section decrease sequentially and move away from the boiler feedwater pump sequentially. The force-bearing component is a force-bearing bearing. The inner ring of the force-bearing bearing is pressed against the second connecting section. The third connecting section is threaded with a fixing nut. The fixing nut is pressed against the inner ring sidewall of the force-bearing bearing. The elastic element acts on the outer ring of the force-bearing bearing.

3. The limiting device for preventing rotor movement of a boiler feedwater pump according to claim 2, characterized in that: The outer ring of the load-bearing bearing is provided with a bearing sleeve for fixing the outer ring of the load-bearing bearing. The bearing sleeve abuts against the circumferential wall of the outer ring of the load-bearing bearing and the side of the outer ring of the load-bearing bearing near the elastic member. The elastic member abuts against the side of the bearing sleeve away from the load-bearing bearing.

4. The limiting device for preventing rotor movement of a boiler feedwater pump according to claim 3, characterized in that: The connecting sleeve is threaded with a fastening screw, which abuts against the bearing sleeve on the side away from the load-bearing bearing.

5. A limiting device for preventing rotor movement of a boiler feedwater pump according to claim 2, characterized in that: The second connecting segment is fitted with an adjusting ring, one side of which abuts against the first connecting segment, and the side of the adjusting ring away from the first connecting segment abuts against the inner ring of the bearing.

6. A limiting device for preventing rotor movement of a boiler feedwater pump according to claim 2, characterized in that: A bearing end cover is installed on the side of the connecting sleeve away from the boiler feed pump, and a connecting assembly is installed on the bearing end cover and the connecting sleeve to fix the two together.

7. A limiting device for preventing rotor movement of a boiler feedwater pump according to claim 6, characterized in that: The connecting assembly includes a double-ended screw and a locking nut. The double-ended screw passes through the bearing end cover and the connecting sleeve. The locking nut abuts against the side of the bearing end cover away from the connecting sleeve, and the locking nut is threadedly connected to the double-ended screw. The end of the double-ended screw away from the locking nut is threadedly connected to the protective casing of the boiler feedwater pump.

8. A limiting device for preventing rotor movement of a boiler feedwater pump according to claim 6, characterized in that: The bearing end cover has a cooling chamber for passing cold water on the side away from the connecting sleeve. The bearing end cover has a water passage hole that communicates with the cooling chamber. A sealing cover that seals the cooling chamber is installed on the side of the bearing end cover away from the connecting sleeve.

9. A limiting device for preventing rotor movement of a boiler feedwater pump according to claim 8, characterized in that: The cooling chamber is equipped with multiple heat dissipation plates to increase the heat dissipation area.

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