Adjustable anti-falling bush for impeller blade handle shaft of induced draft fan

Abstract

The utility model provides an adjustable induced draft fan impeller blade handle shaft anti-falling bush, which relates to the technical field of bushings, and comprises a hub, blades and a flange, and the outer end part of the hub is provided with a blade handle hole. The wear-resistant composite flange bushing with the flange structure is arranged between the flange and the hub, and the flange is mounted on the inner side of the blade handle hole, so that when a centrifugal force is generated during operation of the fan rotor, the flange directly blocks the flange bushing from moving outwards, the effect of the centrifugal force on the flange bushing is counteracted, the flange bushing is effectively prevented from falling off from the blade handle hole, and the service life of the fan rotor is prolonged. The problems of rotation jamming of the blade handle shaft, failure of a blade adjusting function, drifting of movable blades, aggravation of equipment operation vibration and the like caused by falling of the flange lining are avoided, safe and stable operation of a unit is guaranteed, meanwhile, the flange lining is made of a composite material, the composite material has self-lubricating performance and abrasion resistance, the lubricating effect of the blade handle shaft when the blade handle shaft rotates in the blade handle shaft hole is guaranteed, and the service life of the blade handle shaft is prolonged. Friction loss is reduced, and the service life of parts is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of bushing technology, and in particular to an adjustable anti-detachment bushing for the impeller shank shaft of an induced draft fan. Background Technology

[0002] Currently, most 300MW thermal power plants in China use adjustable-blade axial-flow induced draft fans. The core technology of these fans was primarily introduced by domestic brands such as Shanghai Blower Works, Chengdu Electric Power, and Shenyang Blower Works from German companies TLT, German company KKK, and Danish company Novenk in the 1970s and 1980s. Early fan designs were primarily for traditional operating conditions. However, with the increasing environmental emission requirements of thermal power plants, desulfurization and denitrification devices have been added to the flue gas systems, significantly altering the fan operating environment. Currently, the flue gas composition in the modified induced draft fan ducts is complex, commonly containing chemicals such as ammonium bisulfate and sulfur trioxide. These substances react with dust and adhere to the fan blade surface as the flue gas temperature changes, and then penetrate the blade adjustment and rotating components through the blade gaps, causing corrosion and jamming problems.

[0003] The existing designs of existing wind turbine manufacturers are no longer adequate for such harsh operating conditions, revealing numerous defects. Taking the HU25042-22G type adjustable axial flow fan produced by Chengdu Electric Machinery Plant as an example, its original blade bushing design was a ring without a flange, simply glued to the blade bushing hole. During fan rotor operation, under the long-term action of significant centrifugal force, the bushing is at risk of detachment. Once detached, it will cause the blade bushing to jam, the blade adjustment function to fail, leading to blade drift defects, ultimately resulting in increased equipment vibration and seriously threatening the safe and stable operation of the unit. Therefore, improvements are necessary. Utility Model Content

[0004] The purpose of this utility model is to solve the problems mentioned in the background art and to propose an adjustable anti-detachment bushing for the impeller shank of an induced draft fan.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an adjustable impeller shank anti-detachment bushing for an induced draft fan, comprising a hub, blades, and a flange. The outer end of the hub has a shank hole and a shank shaft hole. A shank is fixedly installed at the root of the blade, and a shank shaft is fixedly installed at the root of the shank. A first annular groove and a second annular groove are formed on the outer periphery of the shank. An O-ring seal is provided inside the first annular groove, and a carbon fiber open sealing ring is provided inside the second annular groove. A retaining bushing is provided between the flange and the hub.

[0006] Preferably, the blade shaft passes through the blade shaft hole.

[0007] Preferably, the flange is connected to the hub by bolts.

[0008] Preferably, the flange bushing is a wear-resistant composite bushing.

[0009] Preferably, the first annular groove is located at the outer end of the leaf stalk relative to the second annular groove.

[0010] Preferably, the petiole is embedded in the petiole hole.

[0011] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0012] In this invention, a wear-resistant composite baffle bushing with a baffle structure is installed between the flange and the hub. The baffle is installed inside the blade holder hole. When the fan rotor generates centrifugal force, the baffle directly prevents the baffle bushing from moving outward, thus counteracting the centrifugal force and effectively preventing it from falling out of the blade holder hole. This avoids problems such as blade holder shaft jamming, blade adjustment malfunction, blade drift, and increased equipment vibration caused by the baffle bushing falling out, ensuring the safe and stable operation of the unit. Simultaneously, the baffle bushing is made of a composite material, which combines self-lubrication and wear resistance, ensuring lubrication when the blade holder shaft rotates within the blade holder hole, reducing friction loss, extending component lifespan, and maintaining the good performance of the blade adjustment rotation component. Furthermore, this design includes an O-ring seal in the first annular groove on the outer circumference of the blade holder and a carbon fiber open sealing ring in the second annular groove. This double sealing structure further enhances the sealing performance, effectively preventing corrosive substances in the flue gas from intruding into the connection between the blade holder and the hub. Attached Figure Description

[0013] Figure 1 This utility model provides a partial structural cross-sectional view of an adjustable induced draft fan impeller shank anti-detachment bushing.

[0014] Figure 2 This utility model provides a cross-sectional structural schematic diagram of an adjustable induced draft fan impeller shank anti-detachment bushing.

[0015] Figure 3 This utility model presents a partial structural diagram of an adjustable induced draft fan impeller shank anti-detachment bushing.

[0016] Legend: 1. Hub; 101. Blade shank hole; 102. Blade shank shaft hole; 2. Blade; 3. Blade shank shaft; 4. Flange; 5. Blade shank; 501. First annular groove; 502. Second annular groove; 6. Bolt; 7. Side bushing; 8. O-ring seal; 9. Carbon fiber open sealing ring. Detailed Implementation

[0017] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0018] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.

[0019] Example 1: As Figures 1-3 As shown, this utility model provides a technical solution: an adjustable impeller shank anti-detachment bushing for an induced draft fan, including a hub 1, blades 2, and a flange 4. The outer end of the hub 1 has a shank hole 101 and a shank shaft hole 102. A shank 5 is fixedly installed at the root of the blades 2, and a shank shaft 3 is fixedly installed at the root of the shank 5. A first annular groove 501 and a second annular groove 502 are formed on the outer periphery of the shank 5. An O-ring seal 8 is provided inside the first annular groove 501, and a carbon fiber open sealing ring 9 is provided inside the second annular groove 502. A retaining bushing 7 is provided between the flange 4 and the hub 1. The shank shaft 3 passes through the shank shaft hole 102. The flange 4 and the hub 1 are connected by bolts 6. The retaining bushing 7 is a wear-resistant composite bushing. The first annular groove 501 is located at the outer end of the shank 5, and the shank 5 is embedded in the shank hole 101.

[0020] In this embodiment, a wear-resistant composite baffle bushing 7 with a baffle structure is provided between the flange 4 and the hub 1, and the baffle is installed inside the blade hole 101. When the fan rotor generates centrifugal force, the baffle directly blocks the baffle bushing 7 from moving outward, thus counteracting the effect of centrifugal force on the baffle bushing 7 and effectively preventing it from falling out of the blade hole 101. This avoids problems such as jamming of the blade shaft 3, failure of the blade 2 adjustment function, blade drift, and increased vibration of the equipment due to the baffle bushing 7 falling out, ensuring the safe and stable operation of the unit. At the same time, the baffle... The side bushing 7 is made of composite material, which has both self-lubricating and wear-resistant properties, ensuring the lubrication effect when the blade shaft 3 rotates in the blade shaft hole 102, reducing friction loss, extending the service life of the component, and maintaining the good performance of the blade 2 adjustment and rotation component. Furthermore, this design sets an O-ring seal 8 in the first annular groove 501 on the outer periphery of the blade 5 and a carbon fiber open seal ring 9 in the second annular groove 502. The double sealing structure further improves the sealing performance and effectively prevents corrosive substances in the flue gas from entering the connection between the blade 5 and the hub 1.

[0021] The working principle of this embodiment is as follows: By setting a wear-resistant composite baffle bushing 7 with a baffle structure between the flange 4 and the hub 1, and utilizing the design of the baffle being installed inside the blade hole 101, when the fan rotor generates centrifugal force during operation, the baffle directly prevents the baffle bushing 7 from moving outward, thus counteracting the effect of centrifugal force on the baffle bushing 7 and preventing it from falling out of the blade hole 101. At the same time, the baffle bushing 7 is made of composite material (inner ring PTFE mixed material, middle layer sintered bronze powder, base layer low carbon steel plate, surface copper powder + PTFE composite coating), which has both self-lubricating properties and wear resistance. The system ensures lubrication of the blade shaft 3 when it rotates within the blade shaft hole 102, reducing frictional losses. In addition, an O-ring seal 8 is installed in the first annular groove 501 on the outer periphery of the blade 5, and a carbon fiber open sealing ring 9 is installed in the second annular groove 502. The double sealing structure further enhances the sealing performance, preventing corrosive substances in the flue gas from entering the connection between the blade 5 and the hub 1. Together with the side bushing 7, it ensures smooth rotation of the blade shaft 3, avoiding problems such as blade 2 adjustment jamming and equipment vibration caused by bushing detachment or component corrosion, thus achieving long-term stable operation of the induced draft fan.

[0022] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. An adjustable induced draft fan impeller shank anti-detachment bushing, comprising a hub (1), blades (2) and a flange (4), characterized in that: The outer end of the hub (1) is provided with a blade stalk hole (101) and a blade stalk shaft hole (102). A blade stalk (5) is fixedly installed at the root of the blade (2). A blade stalk shaft (3) is fixedly installed at the root of the blade stalk (5). A first annular groove (501) is provided on the outer periphery of the blade stalk (5). A second annular groove (502) is provided on the outer periphery of the blade stalk (5). An O-ring seal (8) is provided inside the first annular groove (501). A carbon fiber open sealing ring (9) is provided inside the second annular groove (502). A flange bushing (7) is provided between the flange (4) and the hub (1).

2. The adjustable induced draft fan impeller shank anti-detachment bushing according to claim 1, characterized in that: The blade shaft (3) passes through the blade shaft hole (102).

3. The adjustable induced draft fan impeller shank anti-detachment bushing according to claim 1, characterized in that: The flange (4) is connected to the hub (1) by bolts (6).

4. The adjustable induced draft fan impeller shank anti-detachment bushing according to claim 1, characterized in that: The side bushing (7) is a wear-resistant composite bushing.

5. The adjustable induced draft fan impeller shank anti-detachment bushing according to claim 1, characterized in that: The first annular groove (501) is located at the outer end of the petiole (5) relative to the second annular groove (502).

6. The adjustable induced draft fan impeller shank anti-detachment bushing according to claim 1, characterized in that: The petiole (5) is embedded in the petiole hole (101).

Images