Centring device for a centrifugal fan self-aligning roller bearing shafting and method for repairing it

Abstract

The present application relates to the field of centrifuge maintenance, especially to a centrifugal fan self-aligning roller bearing shaft system centering device and a maintenance method, the device comprises: a process bearing and a centering tool, the process bearing is circular ring-shaped and consistent with the size of the self-aligning roller bearing, the centering tool comprises a positioning plate and an adjusting screw rod, the positioning plate has a positioning hole in the center, and the inner wall of the positioning hole is provided with a thread, the diameter of the positioning plate is consistent with the diameter of the bearing seat side cover, the outer wall of the adjusting screw rod is provided with a thread, and the top has a semicircular groove, and the adjusting screw rod passes through the positioning hole, the present application is simple and practical, can ensure that the deviation of the fan shaft system centering is reduced, reduce the bearing temperature when the fan is running, increase the service life of the bearing, reduce the risk of bearing damage, and improve the operation stability of the equipment.

Description

Technical Field

[0001] This invention relates to the field of centrifuge repair, and in particular to a centrifugal fan self-aligning roller bearing shaft alignment device and repair method. Background Technology

[0002] Centrifugal fans are machines that rely on input mechanical energy to increase gas pressure and discharge gas. They are widely used in ventilation, dust removal and cooling in factories, mines, tunnels, cooling towers, vehicles, ships and buildings; ventilation and induced draft in boiler industry furnaces and kilns; cooling and ventilation in air conditioning equipment and household appliances; grain drying and conveying; pneumatic air sources and inflation and propulsion of hovercraft, etc.

[0003] Large centrifugal fans typically use a coupling to connect the fan and motor shaft, with two bearing housings mounted on opposite sides of the casing and the impeller positioned between them. Self-aligning roller bearings are commonly used in these two bearings. However, during installation, commissioning, and maintenance, if the bearing housings are replaced, alignment difficulties arise between the drive and non-drive end bearing housings of the centrifugal fan. Furthermore, since centrifugal fans use coupling transmission, and the drive and non-drive end bearings are self-aligning roller bearings, significant axial movement occurs during coupling alignment, affecting the accuracy of the coupling alignment.

[0004] Because the fan uses self-aligning roller bearings, the bearings can self-adjust and compensate for a certain amount of misalignment in the fan shaft system. However, misalignment of the bearing housing will greatly reduce the operating stability of the fan, reduce the service life of the bearings, and make the fan bearings prone to wear and damage.

[0005] Currently, in the industry, when installing, commissioning, and repairing centrifugal fan bearing housings, the centering position of the bearing housing is adjusted solely by measuring the clearance of the bearing housing ring with a feeler gauge. This method results in large centering deviations, and the alignment effectiveness depends heavily on the skill and experience of the installation and maintenance personnel. The fan bearing cannot be perfectly aligned within this bearing housing. Furthermore, when aligning couplings in centrifugal fans, the self-aligning roller bearings themselves have significant shaft runout, leading to insufficient alignment accuracy of the fan coupling. Both of these situations result in problems such as excessive bearing heat generation and reduced bearing life.

[0006] For example, "An Auxiliary Tooling and Alignment Method for Shaft Alignment" (Patent No.: 202110443035.2) and "An Alignment Tooling and Method for Vertical Pump" (Patent No.: 202110161320.5) both use relatively complex tooling and methods such as lasers. Moreover, if this method is used, it is not suitable for the alignment of centrifugal fan shaft systems because there are obstacles such as impellers and volutes between the laser receiver and transmitter. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a centrifugal fan self-aligning roller bearing shaft alignment device and maintenance method, which is simple and practical, ensures that the alignment deviation of the fan shaft is reduced, reduces the bearing temperature during fan operation, increases the bearing service life, reduces the risk of bearing damage, and improves the stability of equipment operation.

[0008] This invention provides a centrifugal fan self-aligning roller bearing shaft alignment device, comprising: a process bearing and an alignment tool;

[0009] The process bearing is annular and has the same dimensions as the self-aligning roller bearing.

[0010] The centering tool includes a positioning plate and an adjusting screw.

[0011] The positioning plate has a positioning hole in the center, and the inner wall of the positioning hole is provided with threads; the diameter of the positioning plate is the same as the diameter of the bearing seat side cover.

[0012] The outer wall of the adjusting screw is threaded, and the top has a semi-circular groove.

[0013] The adjusting screw passes through the positioning hole.

[0014] Preferably, the outer ring size, inner ring size, and width of the process bearing are all consistent with those of the self-aligning roller bearing.

[0015] Both the inner and outer edges are chamfered.

[0016] Preferably, the process bearing has through holes on its surface, which are evenly arranged around the center.

[0017] Preferably, there are 8 through holes, 4 with threads and 4 without threads, with the threaded through holes and the unthreaded through holes arranged alternately.

[0018] Preferably, a nut is welded into the hole of the positioning plate.

[0019] Preferably, the thickness of the positioning plate is the same as that of the bearing seat side cover.

[0020] This invention also provides a method for aligning and maintaining the self-aligning roller bearing shaft system of a centrifugal fan, utilizing the centrifugal fan self-aligning roller bearing shaft system alignment device described above, comprising the following steps:

[0021] Step 1: Lift the centrifugal fan shaft and impeller;

[0022] Step 2: Install the process bearing onto the mating surface of the bearing at the drive end and the non-drive end of the centrifugal fan shaft;

[0023] Step 3: Lower the centrifugal fan shaft and install process bearings on both the drive end and the non-drive end. Place the process bearings into the bearing housing.

[0024] Step 4: Loosen the anchor bolts on the drive end and non-drive end bearing housings;

[0025] Step 5: Reinstall the bearing housing covers on the drive end and non-drive end, and tighten the split bolts on the bearing housing according to the torque requirements;

[0026] Step 6: Reinstall and tighten the bearing housing anchor bolts according to the torque requirements;

[0027] Step 7: Loosen the split bolts between the drive end and the non-drive end bearing housings and open the bearing housing cover;

[0028] Step 8: Remove the process bearing and reinstall the self-aligning roller bearing;

[0029] Step 9: Install the alignment tool at the non-drive end bearing housing side cover position; install the positioning plate inside the bearing housing; pass the adjusting screw through the positioning hole, and place a steel ball in the semi-circular groove of the adjusting screw;

[0030] Step 10: Reinstall the bearing housing covers and split bolts on both the drive and non-drive ends;

[0031] Step 11: Tighten the adjusting screw of the centering tool to hold the shaft in place; tighten the adjusting screw to completely restrain the displacement of the centrifugal fan shaft system;

[0032] Step 12: Align the coupling. After alignment, remove the alignment tool and reinstall the bearing cover side cover.

[0033] Preferably, in step 11, a dial indicator is axially mounted on the shaft head of the drive end, and the tightening degree of the adjusting screw is precisely controlled by the dial indicator reading.

[0034] Preferably, when the dial indicator reading on the drive shaft changes by 0.01 mm, the tightening of the adjusting screw is stopped.

[0035] Compared with the prior art, the centrifugal fan self-aligning roller bearing shaft alignment device and maintenance method of the present invention are applicable to centrifugal fans in which the fan and motor main shaft are connected by couplings, two bearing seats are respectively mounted on both sides of the casing, and the impeller is placed between the two bearings.

[0036] The method of this invention is simple to operate and easy to learn. It also offers high installation accuracy.

[0037] The tools used in the method of this invention are low in manufacturing cost, requiring only copper pillars, iron plates, bolts, and nuts to complete the process.

[0038] The method of this invention has good post-reassembly results. The temperature of the fan bearing reinstalled using this special tool is about 10°C lower than that of the conventional method, the condition of the bearing grease is also greatly improved, and the blackening of the grease is significantly reduced. Attached Figure Description

[0039] Figure 1 This is a front view of the bearing used in the tooling process of this invention;

[0040] Figure 2 This is a left view of the bearing used in the tooling process of this invention;

[0041] Figure 3 This is a front view of the positioning plate of the special tool for centering the tooling coupling of the present invention;

[0042] Figure 4 This is a left view of the positioning plate of the special tool for centering the tooling coupling of the present invention;

[0043] Figure 5 This is a front view of the adjusting screw of the special tool for centering the tooling coupling of the present invention;

[0044] Figure 6 This is a schematic diagram illustrating the use of the repair method of the present invention.

[0045] 1 is the process bearing; 2 is the alignment tool; 3 is the fan impeller; and 4 is the fan main shaft. Detailed Implementation

[0046] To further understand the present invention, embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the present invention.

[0047] An embodiment of the present invention discloses a centrifugal fan self-aligning roller bearing shaft alignment device, such as... Figures 1-5 As shown, it includes: process bearing 1 and centering tool 2;

[0048] The process bearing 1 is used for aligning the bearing housings at the drive end and non-drive end of the fan.

[0049] The process bearing 1 is annular and has the same dimensions as the self-aligning roller bearing;

[0050] The process bearing 1 is made from a solid cylinder through cutting, drilling, and grinding. The outer ring dimensions, inner ring dimensions, and width of the process bearing are all consistent with those of a self-aligning roller bearing.

[0051] Both the inner and outer rings have chamfered edges to facilitate the installation and removal of the bearings.

[0052] The process bearing has through holes on its surface, which are evenly arranged around the center.

[0053] There are eight through holes, four threaded and four unthreaded, with the threaded and unthreaded through holes spaced apart. This design facilitates quick assembly and disassembly of the process bearings and also reduces tool weight.

[0054] The centering tool 2 is used for centering the fan and motor couplings.

[0055] The centering tool 2 includes a positioning plate and an adjusting screw.

[0056] The positioning plate is cut and shaped from a carbon steel plate of the same thickness as the non-drive end bearing housing side cover. The diameter of the positioning plate is the same as the diameter of the bearing housing side cover.

[0057] The positioning plate has a positioning hole at its center, and the inner wall of the positioning hole is provided with threads.

[0058] Preferably, a nut is welded into the hole of the positioning plate, and the nut can be an M18 nut.

[0059] The thickness of the positioning plate is the same as that of the bearing housing side cover.

[0060] The outer wall of the adjusting screw is threaded, and the top has a semi-circular groove.

[0061] The adjusting screw passes through the positioning hole.

[0062] When the nut can be an M18 nut, the adjusting screw is made from an M18 screw.

[0063] The embodiments of the present invention also disclose a method for aligning and maintaining the self-aligning roller bearing shaft system of a centrifugal fan, which utilizes the centrifugal fan self-aligning roller bearing shaft system alignment device described above, and includes the following steps:

[0064] Step 1: Lift the centrifugal fan shaft and impeller;

[0065] Step 2: Install the process bearing onto the mating surface of the bearing at the drive end and the non-drive end of the centrifugal fan shaft;

[0066] Step 3: Lower the centrifugal fan shaft and install process bearings on both the drive end and the non-drive end. Place the process bearings into the bearing housing.

[0067] Step 4: Loosen the anchor bolts on the drive end and non-drive end bearing housings;

[0068] Step 5: Reinstall the bearing housing covers on the drive end and non-drive end, and tighten the split bolts on the bearing housing according to the torque requirements;

[0069] At this time, since the process bearing cannot be aligned internally, the bearing housing will be driven by torque to be concentric with the shaft, which is equivalent to the drive end bearing housing and the non-drive end bearing housing being concentric with each other.

[0070] Step 6: Reinstall and tighten the bearing housing anchor bolts according to the torque requirements;

[0071] At this time, the bearing housings at the drive end and non-drive end of the fan are in an ideal state. Theoretically, there is no left or right deviation between the bearing housings at the drive end and non-drive end.

[0072] Step 7: Loosen the split bolts between the drive end and the non-drive end bearing housings and open the bearing housing cover;

[0073] Step 8: Remove the process bearing and reinstall the self-aligning roller bearing;

[0074] Step 9: Install the alignment tool at the non-drive end bearing housing side cover position; install the positioning plate inside the bearing housing; pass the adjusting screw through the positioning hole, and place a steel ball in the semi-circular groove of the adjusting screw;

[0075] Step 10: Reinstall the bearing housing covers and split bolts on both the drive and non-drive ends;

[0076] Step 11: Tighten the adjusting screw of the centering tool to hold the shaft in place; tighten the adjusting screw to completely restrain the displacement of the centrifugal fan shaft system;

[0077] Preferably, a dial indicator is axially mounted on the shaft head at the drive end, and the tightening degree of the adjusting screw is precisely controlled by the dial indicator reading;

[0078] When the dial indicator reading on the drive shaft changes by 0.01mm, stop tightening the adjusting screw;

[0079] At this point, the fan shaft displacement is completely restrained, but the presence of the steel balls will not affect the fan's rotation. Aligning the coupling at this stage can significantly reduce axial movement of the coupling, decrease alignment errors in the fan shaft system, and improve installation accuracy.

[0080] Step 12: Align the coupling. After alignment, remove the alignment tool and reinstall the bearing cover side cover.

[0081] By using this special tool for aligning the self-aligning roller bearing shaft system of large centrifugal fans, interference caused by the self-aligning roller bearing can be avoided, thus improving the alignment accuracy of the equipment shaft system and preventing the equipment from operating under adverse conditions.

[0082] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0083] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for aligning and maintaining the shaft system of a centrifugal fan's self-aligning roller bearing, characterized in that... Maintenance is carried out using a centrifugal fan self-aligning roller bearing shaft alignment device, which includes: a process bearing and an alignment tool; The process bearing is annular and has the same dimensions as the self-aligning roller bearing. The centering tool includes a positioning plate and an adjusting screw. The positioning plate has a positioning hole in the center, and the inner wall of the positioning hole is provided with threads; the diameter of the positioning plate is the same as the diameter of the bearing seat side cover. The outer wall of the adjusting screw is threaded, and the top has a semi-circular groove. The adjusting screw passes through the positioning hole; Includes the following steps: Step 1: Lift the centrifugal fan shaft and impeller; Step 2: Install the process bearing onto the mating surface of the bearing at the drive end and the non-drive end of the centrifugal fan shaft; Step 3: Lower the centrifugal fan shaft and install process bearings on both the drive end and the non-drive end. Place the process bearings into the bearing housing. Step 4: Loosen the anchor bolts on the drive end and non-drive end bearing housings; Step 5: Reinstall the bearing housing covers on the drive end and non-drive end, and tighten the split bolts on the bearing housing according to the torque requirements; Step 6: Reinstall and tighten the bearing housing anchor bolts according to the torque requirements; Step 7: Loosen the split bolts between the drive end and the non-drive end bearing housings and open the bearing housing cover; Step 8: Remove the process bearing and reinstall the self-aligning roller bearing; Step 9: Install the alignment tool at the non-drive end bearing housing side cover position; install the positioning plate inside the bearing housing; pass the adjusting screw through the positioning hole, and place a steel ball in the semi-circular groove of the adjusting screw; Step 10: Reinstall the bearing housing covers and split bolts on both the drive and non-drive ends; Step 11: Tighten the adjusting screw of the centering tool to hold the shaft in place; tighten the adjusting screw to completely restrain the displacement of the centrifugal fan shaft system; Step 12: Align the coupling. After alignment, remove the alignment tool and reinstall the bearing cover side cover.

2. The method for aligning and maintaining the self-aligning roller bearing shaft system of a centrifugal fan according to claim 1, characterized in that, In step 11, a dial indicator is axially mounted on the shaft head of the drive end, and the tightening degree of the adjusting screw is precisely controlled by the dial indicator reading.

3. The method for aligning and maintaining the self-aligning roller bearing shaft system of a centrifugal fan according to claim 1, characterized in that, Stop tightening the adjusting screw when the dial indicator reading on the drive shaft changes by 0.01 mm.

4. The method for aligning and maintaining the self-aligning roller bearing shaft system of a centrifugal fan according to claim 1, characterized in that, The outer ring dimensions, inner ring dimensions, and width of the process bearing are all consistent with those of the self-aligning roller bearing. Both the inner and outer edges are chamfered.

5. The method for aligning and maintaining the self-aligning roller bearing shaft system of a centrifugal fan according to claim 4, characterized in that, The process bearing has through holes on its surface, which are evenly arranged around the center.

6. The method for aligning and maintaining the self-aligning roller bearing shaft system of a centrifugal fan according to claim 5, characterized in that, There are 8 through holes, 4 with threads and 4 without threads, with the threaded through holes and the unthreaded through holes arranged alternately.

7. The method for aligning and maintaining the self-aligning roller bearing shaft system of a centrifugal fan according to claim 1, characterized in that, A nut is welded into the hole of the positioning plate.

8. The method for aligning and maintaining the self-aligning roller bearing shaft system of a centrifugal fan according to claim 1, characterized in that, The thickness of the positioning plate is the same as that of the bearing housing side cover.

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