Lubricating sludge discharging device and method for small gear wheel bearing seat of coal mill

Abstract

The application discloses a lubricating dirty oil discharging device and method for a small toothed wheel bearing seat of a coal mill, which comprises a bottom plate, a bearing seat, a large shaft, a tight sleeve, a radial sealing ring, an axial sealing ring, a transparent cover, a bearing cover and a double-row self-aligning roller bearing; the bearing seat is fixed to the bottom plate, the large shaft is arranged through the bearing seat and sleeved with the tight sleeve, the radial sealing ring and the axial sealing ring; the transparent cover and the bearing cover are respectively fixed to two ends of the bearing seat and matched with the corresponding sealing rings, the transparent cover is provided with an oil cup and a dirty oil discharging hole, the bearing cover is provided with a lifting ring screw and a threaded hole; the outer ring of the double-row self-aligning roller bearing is provided with a lubricating oil groove and a lubricating oil hole, and the threaded hole is communicated with the two to form an oil feeding channel. The device can realize precise lubricating grease conveying, efficient dirty oil discharging, impurity blocking, bearing clearance adjustment, heat dissipation and lubrication effect improvement, bearing service life prolonging, maintenance cost reduction and coal mill stable operation guaranteeing.

Description

Technical Field

[0001] This invention belongs to the field of lubrication technology for double-row self-aligning roller bearings, specifically relating to a device and method for discharging lubricating sludge from a small roller bearing housing in a coal mill. Background Technology

[0002] The small roller bearing in a coal mill drives the large gear of a low-speed ball mill to grind and crush coal within the cylinder. The double-row self-aligning roller bearing, as a core load-bearing component, directly impacts the reliability of the equipment. Currently, the outer ring of the small roller bearing in coal mills lacks lubrication grooves and holes; the grease filler nozzle is located outside the cover. After filling, the grease tends to accumulate in the cover cavity under gravity and centrifugal force, making it difficult to enter the bearing roller area, especially resulting in severe lubrication in the rollers furthest from the nozzle.

[0003] Maintenance personnel often overfill grease to improve lubrication, causing excessive grease to adhere to the cover and bearing outer ring, crowding out heat dissipation space and resulting in poor bearing heat dissipation and increased temperature. Long-term insufficient lubrication and overheating can damage the roller oil film, accelerate wear, significantly reduce bearing life, and even lead to burn-out failures, threatening the long-term safe and stable operation of the coal mill. It also significantly increases equipment maintenance costs and workload. The existing structure cannot achieve efficient grease delivery and smooth discharge of old grease, making it difficult to meet the requirements for continuous and reliable equipment operation. Summary of the Invention

[0004] The purpose of this invention is to provide a device and method for discharging lubricating sludge from the bearing housing of a small roller in a coal mill, in order to solve the technical defects of uneven lubrication, grease accumulation, poor heat dissipation, and inability to discharge sludge from the existing small roller bearing housings in coal mills.

[0005] To achieve the above objectives, this application provides the following technical solution: A first aspect of this application provides a device for discharging lubricating sludge from a small gear bearing housing in a coal mill, comprising: Base plate; The bearing housing is fixedly mounted on the upper part of the base plate; A main shaft is inserted inside the bearing housing, and a locking sleeve, a radial sealing ring, and an axial sealing ring are sequentially fitted onto the main shaft; A through cover is fixedly installed at one end of the bearing housing and is sealed to the radial sealing ring. The through cover has an oil cup at the top and a drain hole at the bottom. A bearing cap is fixedly installed at the other end of the bearing housing and is sealed to the axial sealing ring. A lifting eye screw is installed on the top of the bearing cap and a threaded hole is provided below it. A double-row self-aligning roller bearing is disposed in the bearing housing and sleeved on the main shaft. Its outer ring has a lubricating oil groove and a lubricating oil hole. The threaded hole is coaxially connected with the lubricating oil groove and the lubricating oil hole to form a lubrication channel.

[0006] In one optional embodiment, the radial sealing ring is fixedly sleeved on the large shaft and fits against the inner sidewall of the cover, forming a dynamic and static sealing fit. The axial sealing ring is fixedly sleeved on the main shaft and fits against the inner wall of the bearing cover, forming a dynamic and static sealing fit, which is used to prevent external dust from entering the bearing housing and contaminating the lubricating grease.

[0007] In one alternative embodiment, the eye bolt is detachably connected to the top end face of the bearing cap via a threaded pair; The threaded hole is coaxially located on the bearing cap directly below the eye bolt and is connected to the lubricating oil groove.

[0008] In one optional embodiment, the oil cup is fixedly mounted on the upper part of the transparent cap; The drain hole is vertically located directly below the cover, and a sealing bolt is threaded onto the drain hole to achieve sealing and opening of the drain hole.

[0009] In one optional embodiment, the through cover and the bearing cover are fastened together by connecting bolts, and the through cover and the bearing cover respectively abut against the outer sides of both ends of the double row self-aligning roller bearing to axially limit the double row self-aligning roller bearing within the internal cavity of the bearing housing.

[0010] In one optional embodiment, the adapter sleeve is coaxially fitted at the mating part between the main shaft and the inner ring of the double-row self-aligning roller bearing, and the two ends of the adapter sleeve respectively abut against the shoulder of the main shaft and the end face of the inner ring of the double-row self-aligning roller bearing, for realizing the clearance adjustment of the double-row self-aligning roller bearing.

[0011] In one optional embodiment, the lubricating oil groove is an annular groove, which is opened circumferentially along the outer peripheral wall of the outer ring of the double-row self-aligning roller bearing. The lubricating oil holes are provided in multiple ways and are evenly distributed along the circumference of the lubricating oil groove. One end of each lubricating oil hole is connected to the lubricating oil groove, and the other end extends through to the roller raceway of the double-row self-aligning roller bearing.

[0012] In one optional embodiment, the centerline of the lubrication channel is arranged along the vertical centerline of the eye bolt, and the diameter of the lubrication channel is adapted to the diameter of the threaded hole, so that the lubricating grease can be pressed along the lubrication channel to the roller raceway of the double-row self-aligning roller bearing.

[0013] In one optional embodiment, the outer ring of the double-row self-aligning roller bearing is clearance-fitted to the inner wall of the bearing housing, and the inner ring of the double-row self-aligning roller bearing is interference-fitted to the outer peripheral wall of the shaft via a locking sleeve.

[0014] A second aspect of this application provides a method for discharging lubricating sludge from a small roller bearing housing in a coal mill, applied to the lubricating sludge discharge device for a small roller bearing housing in a coal mill as described above, comprising the following steps: Remove the eye bolts on the top of the bearing cap, connect the grease injection tool connector to the threaded hole on the bearing cap, and inject lubricating grease into the grease channel. The grease is evenly delivered to the roller raceway through the lubricating oil groove and lubricating oil hole to form a lubricating film. After the lubricating film is formed, loosen the sealing bolt on the drain hole of the cover to discharge the accumulated oil and grease in the bearing housing from the drain hole. After discharge, tighten the sealing bolt to achieve a seal. After the seal is achieved, the eye bolt is screwed back onto the top end face of the bearing cover through the threaded pair to restore the initial structure of the device.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. By creating lubricating oil grooves and holes on the outer ring of the double-row self-aligning roller bearing, and using the threaded holes in the bearing cap to form an oiling channel, the lubricating grease is precisely delivered to the roller raceway, solving the problems of grease difficulty entering the bearing and uneven lubrication. A drain hole is provided at the bottom of the cover to achieve efficient discharge of waste oil and grease, preventing grease accumulation and obstruction of heat dissipation space. Radial and axial sealing rings, together with the cover and bearing cap, block external impurities while ensuring reliable sealing. The locking sleeve enables precise adjustment of bearing clearance, improving operational stability, ensuring uniform distribution of lubricating grease, improving heat dissipation, extending bearing life, reducing maintenance costs, and ensuring long-term safe and stable operation of the coal mill.

[0016] 2. Through the dual dynamic and static sealing structure, it can effectively prevent external dust, coal dust, water vapor and other impurities from entering the bearing housing, avoiding contamination of lubricating grease and wear of bearing rollers and raceways, ensuring the cleanliness of lubricating grease and the lubrication effect of bearing, while preventing lubricating grease leakage in the bearing housing, avoiding grease waste and equipment contamination, improving the sealing reliability of the device, and providing a clean internal environment for stable bearing operation.

[0017] 3. The eye bolts can be used as lifting force points for the disassembly and assembly of the bearing cover, which facilitates equipment inspection and maintenance. They also ensure precise connection between the threaded hole and the lubricating oil groove, providing a stable positioning reference for the refueling channel, ensuring the coaxiality of the lubricating grease delivery path, avoiding obstruction of grease delivery due to channel offset, improving the smoothness of the refueling channel, and ensuring that the lubricating grease is accurately added to the bearing lubrication part.

[0018] 4. The upper oil cup can provide small amounts of lubrication daily, complementing the main oil filling channel and meeting the lubrication needs of different working conditions; the drain hole, vertically located directly below the cover, is designed to accommodate the natural deposition of sludge and grease. With the sealing bolt, it can be flexibly switched between sealing and opening, ensuring that sludge and grease can be smoothly and completely discharged under gravity, and effectively preventing lubricating grease leakage during coal mill operation.

[0019] 5. By limiting the position, the structural stability of the connection between the cover, bearing cover and bearing housing is improved, and the end cover is prevented from loosening due to equipment vibration during the operation of the coal mill. At the same time, the bearing is precisely axially limited in the internal cavity of the bearing housing to prevent axial movement of the bearing during operation, ensure the fitting accuracy of the bearing and other components, reduce wear caused by movement, and improve the overall operating stability of the bearing.

[0020] 6. By tightening the adapter sleeve, the inner ring of the double-row self-aligning roller bearing can be moved axially, thereby precisely adjusting the radial clearance of the bearing and keeping the clearance within the optimal operating range. This ensures the bearing's load-bearing capacity, reduces frictional losses during operation, and lowers the bearing's temperature rise. At the same time, the adapter sleeve makes bearing disassembly and maintenance more convenient, allowing bearing replacement without disassembling the main shaft, thus reducing equipment maintenance time and workload.

[0021] 7. The annular lubricating oil groove can store a certain amount of lubricating grease, realizing the uniform distribution of grease; multiple circumferentially evenly distributed lubricating oil holes directly deliver grease to the roller raceway, realizing all-round and uniform lubrication of the two rows of rollers in the bearing, completely solving the problem of insufficient lubrication of the rollers on the side away from the oil cup in the existing technology, ensuring that a uniform lubricating film is formed on the friction surface between the roller and the raceway, and greatly improving the bearing lubrication quality.

[0022] 8. The refueling channel has a vertical, straight structure with a seamless, stepless flow throughout, effectively overcoming the effects of gravity and centrifugal force on grease delivery. This allows the lubricating grease to be smoothly and unimpededly delivered to the roller raceway under the pressure of injection, preventing grease from stagnating or accumulating during delivery. At the same time, it ensures a stable grease delivery flow rate, ensuring that the lubricating grease is accurately and efficiently delivered to the core lubrication points of the bearing, improving grease utilization and lubrication efficiency.

[0023] 9. The clearance fit between the outer ring and the inner wall of the bearing housing allows for slight thermal expansion during bearing operation, preventing bearing jamming due to thermal expansion. At the same time, it ensures that the outer ring of the bearing remains stationary, ensuring that the lubricating oil groove, lubricating oil hole and threaded hole are always precisely connected. The inner ring, through the interference fit between the adapter sleeve and the main shaft, realizes the synchronous rotation of the bearing and the main shaft, ensuring the stability of power transmission, reducing relative sliding wear at the mating points, and extending the service life of the bearing and the main shaft. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram of a lubricating sludge discharge device for a small gear bearing seat in a coal mill, provided by the present invention; Figure 2 A schematic diagram of the small roller bearing device in an existing coal mill; In the diagram: 1. Radial sealing ring; 2. Oil cup; 3. Eye bolt; 4. Bearing cap; 5. Axial sealing ring; 6. Through cover; 7. Bearing; 8. Main shaft; 9. Threaded hole; 10. Lubricating oil groove; 11. Lubricating oil hole; 12. Bearing with lubricating oil groove and oil hole; 13. Drain hole; 14. Bearing housing; 15. Base plate; 16. Set sleeve. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0029] To address the technical deficiencies mentioned in the background section, this embodiment provides a device and method for discharging lubricating sludge from the small roller bearing housing of a coal mill. The device, applied to the small roller housing of a positive-pressure direct-fired low-speed steel ball coal mill, solves existing technical defects such as difficulty in getting lubricating grease into the roller raceway, uneven lubrication, ineffective discharge of sludge, and poor bearing heat dissipation. It achieves precise lubrication and smooth discharge of waste grease, improving the lubrication quality and heat dissipation of double-row self-aligning roller bearings, extending bearing life, ensuring long-term safe and stable operation of the coal mill, and reducing equipment maintenance costs and workload.

[0030] The present invention also provides a method for discharging lubricating oil adapted to the device, which is simple to operate and highly operable. It can complete the lubrication and oil discharge operations without disassembling the entire bearing housing structure, greatly reducing the daily workload of maintenance personnel.

[0031] The present invention will now be described in further detail with reference to the accompanying drawings: like Figure 1 As shown, in a first aspect of the present invention, a lubricating sludge discharge device for a small gear bearing seat in a coal mill is provided, comprising: a base plate 15; a bearing seat 14, fixedly mounted on the upper part of the base plate 15; a main shaft 8, passing through the interior of the bearing seat 14, with a locking sleeve 16, a radial sealing ring 1, and an axial sealing ring 5 sequentially fitted on the main shaft 8; a through cover 6, fixedly mounted on one end of the bearing seat 14, sealingly cooperating with the radial sealing ring 1, with an oil cup 2 at the upper part of the through cover 6 and a sludge discharge hole 13 at the lower part; a bearing cover 4, fixedly mounted on the other end of the bearing seat 14, sealingly cooperating with the axial sealing ring 5, with a lifting eye screw 3 mounted on the top of the bearing cover 4 and a threaded hole 9 below it; and a double-row self-aligning roller bearing 7, disposed inside the bearing seat 14 and fitted on the main shaft 8, with a lubricating oil groove 10 and a lubricating oil hole 11 on its outer ring, the threaded hole 9 coaxially communicating with the lubricating oil groove 10 and the lubricating oil hole 11 to form an oiling channel.

[0032] In this embodiment, the bearing housing 14 is fixedly mounted on the upper part of the base plate 15, and the main shaft 8 passes through the interior of the bearing housing 14, serving as the power transmission component of the small gear device of the coal mill. The locking sleeve 16, the radial sealing ring 1, and the axial sealing ring 5 are sequentially sleeved along the axial direction of the main shaft 8, respectively realizing bearing clearance adjustment and sealing protection; the through cover 6 is fixedly mounted on one end of the bearing housing 14 and seals with the radial sealing ring 1. The through cover 6 has an oil cup 2 at the top and a drain hole 13 at the bottom, respectively realizing auxiliary lubrication and draining of waste oil; the bearing cover 4 is fixedly mounted on the shaft. At the other end of the bearing housing 14, it is sealed with the axial sealing ring 5. The top of the bearing cover 4 is equipped with a lifting eye screw 3, and a threaded hole 9 is opened directly below it. The double-row self-aligning roller bearing 7 is located in the internal cavity of the bearing housing 14 and is coaxially sleeved on the main shaft 8. Its outer ring is provided with a lubricating oil groove 10 and a lubricating oil hole 11. The threaded hole 9 on the bearing cover 4 is coaxially connected with the lubricating oil groove 10 and the lubricating oil hole 11 of the double-row self-aligning roller bearing 7, forming a lubrication channel that directly reaches the roller raceway, ensuring that the lubricating grease can be accurately and efficiently delivered to the bearing lubrication part.

[0033] Furthermore, the base plate 15 is a flat structure formed by processing steel plate. Its size is adapted to the bottom mounting surface of the bearing seat 14. Multiple mounting holes are opened on the surface. It is fixedly connected to the foundation frame of the coal mill by expansion bolts or anchor bolts, providing stable support for the bearing seat 14 and preventing the bearing seat 14 from shifting or loosening due to equipment vibration during the operation of the coal mill.

[0034] The bearing housing 14 is a one-piece cast steel structure with an internal mounting cavity adapted to the double-row self-aligning roller bearing 7. Its bottom is connected to the upper part of the base plate 15 by welding or bolting, and the connection is reinforced to meet the radial and axial load requirements of the small gear device of the coal mill.

[0035] The bearing housing 14 has mounting end faces at both ends that are adapted to the through cover 6 and the bearing cover 4. Bolt holes are provided on the mounting end faces for fixing the through cover 6 and the bearing cover 4. The machining accuracy of the mounting end faces is Ra3.2 or less to ensure a tight seal with the through cover 6 and the bearing cover 4, preventing external dust and moisture from entering the internal cavity and contaminating the lubricating grease. The inner wall of the bearing housing 14 has a clearance fit with the outer ring of the double-row self-aligning roller bearing 7, with a clearance of 0.02-0.05mm. This ensures the installation stability of the outer ring of the double-row self-aligning roller bearing 7 within the bearing housing 14 and also provides space for minor thermal expansion during bearing operation, preventing bearing jamming due to thermal expansion.

[0036] The main shaft 8 is the power shaft of the small gear unit of the coal mill. It is forged from alloy structural steel. The machining accuracy and surface roughness of its outer peripheral wall meet the bearing assembly requirements, avoiding wear of the bearing inner ring due to excessive shaft surface roughness.

[0037] The locking sleeve 16, the radial sealing ring 1, and the axial sealing ring 5 are sequentially fitted along the axial direction of the main shaft 8, and all three are interference-fitted with the outer peripheral wall of the main shaft 8 to ensure synchronous rotation with the main shaft 8 without relative slippage.

[0038] The adapter sleeve 16 is a standard tapered adapter sleeve, which is coaxially sleeved at the mating part between the main shaft 8 and the inner ring of the double-row self-aligning roller bearing 7. Its tapered surface is adapted to the tapered hole of the inner ring of the double-row self-aligning roller bearing 7. The two ends of the adapter sleeve 16 abut against the shoulder of the main shaft 8 and the end face of the inner ring of the double-row self-aligning roller bearing 7, respectively.

[0039] By tightening the locking nut of the locking sleeve 16, the inner ring of the double-row self-aligning roller bearing 7 can be moved axially, thereby precisely adjusting the radial clearance of the double-row self-aligning roller bearing 7 and keeping the bearing clearance within the optimal operating range. This ensures the bearing's load-bearing capacity and reduces frictional losses during operation. At the same time, the locking sleeve 16 facilitates the disassembly, assembly, and maintenance of the double-row self-aligning roller bearing 7, allowing for bearing replacement without disassembling the main shaft 8.

[0040] Both the radial sealing ring 1 and the axial sealing ring 5 are made of nitrile rubber, possessing excellent wear resistance, oil resistance, and sealing performance. The radial sealing ring 1 is fixedly sleeved on the main shaft 8 and tightly fitted with the inner wall of the cover 6, forming a dynamic and static sealing fit. The axial sealing ring 5 is fixedly sleeved on the main shaft 8 and tightly fitted with the inner wall of the bearing cover 4, also forming a dynamic and static sealing fit. This effectively prevents external dust, coal dust, water vapor, and other impurities from entering the internal cavity of the bearing housing 14, preventing impurities from contaminating the lubricating grease, wearing the bearing rollers and raceways, ensuring the cleanliness of the lubricating grease and the lubrication effect of the bearing, and also preventing the leakage of lubricating grease inside the bearing housing 14, avoiding grease waste and equipment contamination.

[0041] In this embodiment, the through cover 6 is an end cover structure formed by casting steel. Its shape is adapted to the mounting end face of one end of the bearing seat 14. It is fixed to one end of the bearing seat 14 by connecting bolts. The inner side wall of the through cover 6 is tightly fitted with the outer peripheral surface of the radial sealing ring 1 to ensure the sealing effect.

[0042] The through cover 6 and the bearing cover 4 are fastened together by M16×45 connecting bolts. The connecting bolts are evenly distributed around the mating end faces of the through cover 6 and the bearing cover 4 to ensure connection strength and tight sealing.

[0043] An oil cup 2 is fixedly mounted on the upper part of the cover 6. The oil cup 2 is an M10×1 screw-cap type oil cup, which is a conventional auxiliary lubrication component for coal mill bearings. Lubricating grease can be replenished by unscrewing the oil cup cap. It is suitable for daily small-volume lubrication replenishment and complements the main lubrication channel on the side of the bearing cover 4 to meet the lubrication needs under different operating conditions. The connection between the oil cup 2 and the cover 6 is a threaded seal connection, and a sealing ring is installed to prevent grease leakage.

[0044] Furthermore, a drain hole 13 is vertically provided at the lower part of the cover 6. The drain hole 13 is an M12 threaded hole, located directly below the cover 6. This location is the natural deposition point for sludge and grease inside the bearing housing 14, ensuring that the sludge and grease can be smoothly discharged under gravity without residue. A sealing bolt is threaded onto the drain hole 13. The sealing bolt is an M12×15 hexagon socket head cap bolt. A sealing washer is installed at the mating part between the bolt and the drain hole 13 to achieve a reliable seal and prevent lubricating grease from leaking from the drain hole 13 during the operation of the coal mill. Loosening the sealing bolt opens the drain hole 13 for sludge discharge, and tightening the sealing bolt restores the seal after discharge. The operation is simple and the seal is reliable.

[0045] Furthermore, the bearing cover 4 is an end cover structure formed by casting steel. Its shape is adapted to the mounting end face of the other end of the bearing seat 14. It is fixed to the other end of the bearing seat 14 by connecting bolts. The inner side wall of the bearing cover 4 is tightly fitted with the outer peripheral surface of the axial sealing ring 5 to ensure the sealing fit effect.

[0046] The bearing cover 4 and the through cover 6 respectively abut against the outer sides of both ends of the double row self-aligning roller bearing 7, together axially limiting the double row self-aligning roller bearing 7 within the internal cavity of the bearing housing 14, preventing axial movement of the double row self-aligning roller bearing 7 during operation, and ensuring the operating stability of the bearing.

[0047] The top end face of the bearing cover 4 is detachably connected to an eye bolt 3 via a threaded pair. The eye bolt 3 is a standard M16 eye bolt, which provides a lifting force point for the installation and removal of the bearing cover 4, facilitating equipment maintenance, and also provides a positioning reference for the opening of the lubrication channel. A threaded hole 9 is coaxially opened on the bearing cover 4 directly below the eye bolt 3. The threaded hole 9 is an M6×1 threaded hole, and its drilling depth penetrates the installation wall thickness of the bearing cover 4, reaching the outer ring of the double row self-aligning roller bearing 7. The threaded hole 9 is connected to the lubrication groove 10 of the outer ring of the double row self-aligning roller bearing 7, and is a core component of the lubrication channel.

[0048] The eye bolt 3 and the bearing cap 4 are precision threaded, with no clearance between the mating parts, preventing external impurities from entering the bearing housing 14 through thread gaps. Disassembly and assembly are also convenient, requiring no special tools, facilitating rapid lubrication operations. The machining precision of the threaded hole 9 is strictly controlled, with a smooth, burr-free inner wall, ensuring unobstructed and residue-free lubricant delivery.

[0049] In this embodiment, the outer ring of the double-row self-aligning roller bearing 7 has a lubricating oil groove 10 and a lubricating oil hole 11 on its outer peripheral wall, which differs from the prior art. Figure 2The bearing structure without lubricating oil grooves and lubricating oil holes is a key structure for achieving precise delivery of lubricating grease.

[0050] The inner ring of the double-row self-aligning roller bearing 7 is interference-fitted with the outer peripheral wall of the main shaft 8 through the locking sleeve 16, so as to achieve synchronous rotation with the main shaft 8; the outer ring is clearance-fitted with the inner wall of the bearing housing 14, so as to keep it fixed and ensure that the positions of the lubricating oil groove 10 and the lubricating oil hole 11 are fixed, and always coaxially connected with the threaded hole 9 on the bearing cover 4, so as to ensure smooth oiling channel.

[0051] The lubricating oil groove 10 is an annular groove, opened along the entire circumference of the outer ring of the double-row self-aligning roller bearing 7. The groove width and depth are designed according to the bearing specifications and lubricating grease flow rate to ensure that a certain amount of lubricating grease can be stored and to achieve uniform distribution of lubricating grease. Multiple lubricating oil holes 11 are provided, which are evenly spaced along the circumference of the lubricating oil groove 10. The diameter of the lubricating oil holes 11 is 4mm, which is compatible with the diameter of the threaded hole 9 to ensure a stable flow rate of lubricating grease. One end of each lubricating oil hole 11 is connected to the lubricating oil groove 10, and the other end extends radially inward along the double-row self-aligning roller bearing 7 to its roller raceway, reaching the core lubrication part of the bearing, so that the lubricating grease can be directly delivered to the contact surface between the roller and the raceway to form an effective lubricating film.

[0052] The evenly distributed arrangement of multiple lubrication holes 11 allows the lubricating grease to be diverted from the lubrication groove 10 and evenly delivered to the raceways of the two rows of rollers in the double-row self-aligning roller bearing 7. This solves the problem of insufficient lubrication of the rollers on the side away from the oil cup in the prior art, achieving all-round and uniform lubrication of the bearing and greatly improving the lubrication quality.

[0053] In this embodiment, the oil filling channel is formed by the threaded hole 9 on the bearing cover 4, the lubricating oil groove 10 on the outer ring of the double-row self-aligning roller bearing 7, and the lubricating oil hole 11 connected coaxially in sequence. It is the channel for transporting lubricating grease from the outside of the bearing to the roller raceway. Its center line is arranged along the vertical center axis of the eye bolt 3 to ensure that the oil filling channel is a vertical straight structure without bending or offset, so that the lubricating grease can be smoothly transported under the action of injection force without resistance loss.

[0054] The diameter of the lubrication channel is matched with the diameter of the threaded hole 9. The inner wall of the entire channel is smoothed, without burrs or steps, to prevent lubricating grease from stagnating or accumulating during transportation. The vertical layout of the lubrication channel, combined with the pressure injection process, can effectively overcome the influence of gravity and centrifugal force, allowing the lubricating grease to be directly pressure delivered to the raceway of the rotating bearing rollers. This solves the technical defect in the existing technology that lubricating grease is difficult to enter the core lubrication part of the bearing, and achieves precise and efficient lubrication.

[0055] In a second aspect, this invention provides a method for discharging lubricating sludge from a small gear bearing housing in a coal mill, applied to the lubricating sludge discharge device for the small gear bearing housing in a coal mill as described above, comprising the following steps: Step 1: Remove the eye bolts on the top of the bearing cover, connect the grease injection tool connector to the threaded hole on the bearing cover, and inject lubricating grease into the grease channel. The grease is evenly delivered to the roller raceway through the lubricating oil groove and lubricating oil hole to form a lubricating film. For example, first, remove the eye bolt 3 on the top of the bearing cover 4 by manually turning it counterclockwise without special tools until the eye bolt 3 is completely disengaged from the threaded part on the bearing cover 4, exposing the threaded hole 9 below, ensuring that the passage of the threaded hole 9 is unobstructed. Then, connect the grease gun's flexible lubricating rod to the threaded hole 9 on the bearing cover 4 for a threaded seal connection. During the connection process, ensure that the connector and the threaded hole 9 fit tightly without gaps to prevent leakage during lubrication.

[0056] After the connection is completed, lubricating grease is slowly injected into the lubrication channel using a grease injection tool. The lubricating grease used is a high-temperature grease specifically for coal mill bearings, which meets the lubrication requirements for high-temperature operation of the bearing. During the injection process, under the action of the injection force, the lubricating grease passes through the threaded hole 9 and the lubricating oil groove 10 in sequence along the lubrication channel. After being evenly distributed by the lubricating oil groove 10, it is precisely delivered to the raceway of the double-row self-aligning roller bearing 7 through multiple circumferentially arranged lubricating oil holes 11, directly contacting the friction surface between the roller and the raceway. A uniform and dense lubricating film is formed on the friction surface, achieving effective lubrication of the double-row self-aligning roller bearing 7. The lubricating film can effectively reduce the frictional loss between the roller and the raceway and lower the bearing operating temperature.

[0057] The amount of lubricating grease injected is determined according to the operating conditions and lubrication requirements of the bearing. Generally, it is advisable to allow slight oil seepage from the sealing part of the cover 6 to ensure that the amount of lubricating grease inside the bearing is sufficient and there is no excessive accumulation, so as to avoid poor heat dissipation caused by excessive grease.

[0058] Step 2: After the lubricating film is formed, loosen the sealing bolt on the drain hole of the cover to drain the dirty oil and waste grease deposited in the bearing housing from the drain hole. After draining, tighten the sealing bolt to achieve a seal. For example, after the aforementioned lubricating film is formed, i.e., after the lubricating grease is added and the lubricating film effectively covers the friction surface of the roller raceway, the sludge discharge operation is carried out. During the operation of the coal mill, the lubricating grease inside the bearing housing 14 will age and deteriorate due to high temperature and wear, forming sludge and waste grease, and at the same time, a small amount of impurities will be mixed in. Under the action of gravity, this sludge and waste grease will be deposited at the sludge discharge hole 13 directly below the cover 6. This step is based on this deposition characteristic to achieve the smooth discharge of sludge and waste grease.

[0059] In practice, use an Allen wrench to loosen the sealing bolts on the drain hole 13 of the cover 6. The loosening direction is counterclockwise. It is not necessary to completely remove the sealing bolts; just loosen them until the drain hole 13 is open. At this time, the dirty oil and waste grease deposited inside the bearing housing 14 will be naturally discharged from the drain hole 13 under the action of gravity. During the discharge process, the dirty oil and waste grease can be collected with an oil receiving container to avoid polluting the equipment and the site environment. After the dirty oil and waste grease have been completely discharged, tighten the sealing bolts clockwise to ensure a tight fit between the sealing bolts and the drain hole 13, and to compact the sealing gasket, thereby achieving a reliable seal of the drain hole 13 and preventing lubricating grease leakage during subsequent operation of the coal mill.

[0060] The grease discharge operation in this step can be carried out simultaneously with the lubrication operation. When injecting new lubricating grease, the new grease will squeeze the grease and waste grease inside the bearing housing 14, making the discharge of grease and waste grease more thorough, achieving the lubrication effect of replacing the old with the new, and further improving the lubrication quality of the bearing.

[0061] Step 3: After achieving the seal, screw the lifting eye screw back onto the top end face of the bearing cover through the threaded pair to restore the initial structure of the device.

[0062] For example, after sealing the drain hole 13, i.e., after completing the lubrication and drain operations, the device is reset to ensure it returns to its initial assembly structure and meets the normal operation requirements of the coal mill. Specifically, the eye bolt 3 is aligned with the threaded engagement portion on the top of the bearing cover 4, and manually screwed clockwise to secure it to the top face of the bearing cover 4. Tightening continues until the eye bolt 3 is flush with the top face of the bearing cover 4 without any looseness, ensuring the stability of the eye bolt 3 installation.

[0063] After resetting, the lubricating oil discharge device of the small gear bearing seat of the coal mill is restored to its initial structure, the oiling channel is sealed to prevent external impurities from entering and causing blockage, and the lifting eye screw 3 regains its lifting function, facilitating subsequent equipment maintenance. The entire resetting operation is simple and quick, enabling rapid equipment restoration and reducing downtime for coal mill maintenance.

[0064] The lubricating sludge discharge method of the present invention provides a pressure basis for sludge discharge during lubrication, provides a clean internal environment for lubrication during sludge discharge, and ensures that the device returns to its operating state during resetting. The three steps work together to achieve efficient lubrication of the bearing and thorough discharge of sludge. Moreover, the entire operation process does not require special equipment or professional technicians and can be completed independently by on-site maintenance personnel, which greatly improves the convenience and efficiency of coal mill bearing maintenance.

[0065] By setting up a dedicated oiling channel, the lubricating grease is directly pressed into the raceway of the double-row self-aligning roller bearing 7. Combined with multiple circumferentially evenly distributed lubricating oil holes 11, the lubricating grease can evenly cover the friction surfaces of the two rows of rollers, forming an effective lubricating film. This completely solves the problem in the prior art that the lubricating grease is difficult to enter the core part of the bearing and that the rollers on the side away from the oil cup are not adequately lubricated, thus greatly improving the lubrication quality of the bearing.

[0066] A drain hole 13 is provided at the location of the oil deposit in the cover 6, which can periodically or at any time completely drain the aged oil and waste grease inside the bearing housing 14, prevent the oil and waste grease from accumulating inside the bearing housing 14 and crowding out the heat dissipation space, and prevent the oil and waste grease from contaminating the new lubricating grease, ensuring the cleanliness and heat dissipation effect inside the bearing, effectively reducing the bearing operating temperature, and avoiding failures such as oil film melting and bearing burnout caused by high temperature.

[0067] The device of this invention can complete lubrication and sludge discharge operations without disassembling the overall structure. The removal of the eye bolt 3, the connection of the grease injection tool, and the loosening of the sealing bolt are all simple manual operations. The corresponding lubricating sludge discharge method has a smooth and short procedure time, which can be completed quickly by on-site maintenance personnel. This greatly reduces the daily workload of maintenance personnel, while also reducing the downtime of the coal mill for maintenance and increasing the effective operating time of the equipment.

[0068] By improving the lubrication quality and heat dissipation of the bearings, the frictional loss between the rollers and raceways is effectively reduced, avoiding problems such as increased wear and reduced lifespan caused by poor lubrication and high temperature. This significantly extends the service life of the double-row self-aligning roller bearing 7, reduces the frequency of bearing replacement, and thus lowers the cost of bearing spare parts and the labor cost of bearing replacement. It also reduces unplanned downtime losses in the coal mill caused by bearing failure, saving the company a significant amount of equipment maintenance expenses.

[0069] The device of this invention adopts a double-sealed structure to effectively block external impurities and ensure the cleanliness of the lubricating grease. At the same time, the bearing clearance is precisely adjusted by the locking sleeve 16 to ensure the running stability of the bearing. Combined with efficient lubrication and heat dissipation, the failure rate of the small toothed gear device of the coal mill is greatly reduced, ensuring the long-term safe and stable operation of the coal mill. It is suitable for the industrial continuous production needs of positive pressure direct-fired low-speed steel ball coal mill.

[0070] In summary, the lubricating sludge discharge device for the small roller bearing housing of the coal mill of the present invention fundamentally solves the technical defects of existing lubrication of small roller bearings in coal mills through the oiling channel and the sludge discharge channel. The corresponding lubricating sludge discharge method is simple to operate and has a continuous process, which can achieve efficient lubrication of the bearing and thorough discharge of sludge. The device and method of the present invention have strong adaptability and significant application effects, which greatly improve the lubrication quality and operational stability of the small roller bearing of the coal mill, extend the service life of the bearing, reduce equipment maintenance costs, and provide reliable technical guarantee for the long-term safe and stable operation of the coal mill. It has good prospects for industrial application and promotion value.

[0071] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for discharging lubricating sludge from the bearing seat of a small gear in a coal mill, characterized in that, include: Base plate; The bearing housing is fixedly mounted on the upper part of the base plate; A main shaft is inserted inside the bearing housing, and a locking sleeve, a radial sealing ring, and an axial sealing ring are sequentially fitted onto the main shaft; A through cover is fixedly installed at one end of the bearing housing and is sealed to the radial sealing ring. The through cover has an oil cup at the top and a drain hole at the bottom. A bearing cap is fixedly installed at the other end of the bearing housing and is sealed to the axial sealing ring. A lifting eye screw is installed on the top of the bearing cap and a threaded hole is provided below it. A double-row self-aligning roller bearing is disposed in the bearing housing and sleeved on the main shaft. Its outer ring has a lubricating oil groove and a lubricating oil hole. The threaded hole is coaxially connected with the lubricating oil groove and the lubricating oil hole to form a lubrication channel.

2. The lubricating sludge discharge device for the small gear bearing seat of a coal mill according to claim 1, characterized in that, The radial sealing ring is fixedly sleeved on the large shaft and fits against the inner side wall of the cover, forming a dynamic and static sealing fit. The axial sealing ring is fixedly sleeved on the main shaft and fits against the inner wall of the bearing cover, forming a dynamic and static sealing fit, which is used to prevent external dust from entering the bearing housing and contaminating the lubricating grease.

3. The lubricating sludge discharge device for the small gear bearing seat of a coal mill according to claim 1, characterized in that, The eye bolt is detachably connected to the top end face of the bearing cap via a threaded pair; The threaded hole is coaxially located on the bearing cap directly below the eye bolt and is connected to the lubricating oil groove.

4. The lubricating sludge discharge device for the small gear bearing seat of a coal mill according to claim 1, characterized in that, The oil cup is fixedly mounted on the upper part of the transparent cover; The drain hole is vertically located directly below the cover, and a sealing bolt is threaded onto the drain hole to achieve sealing and opening of the drain hole.

5. The lubricating sludge discharge device for the small gear bearing seat of a coal mill according to claim 1, characterized in that, The through cover and the bearing cover are fastened together by connecting bolts. The through cover and the bearing cover respectively abut against the outer sides of both ends of the double row self-aligning roller bearing to axially limit the double row self-aligning roller bearing within the internal cavity of the bearing housing.

6. The lubricating sludge discharge device for the small gear bearing seat of a coal mill according to claim 1, characterized in that, The adapter sleeve is coaxially fitted at the mating part between the main shaft and the inner ring of the double-row self-aligning roller bearing, and the two ends of the adapter sleeve respectively abut against the shoulder of the main shaft and the end face of the inner ring of the double-row self-aligning roller bearing, so as to realize the clearance adjustment of the double-row self-aligning roller bearing.

7. The lubricating sludge discharge device for the small gear bearing seat of a coal mill according to claim 1, characterized in that, The lubricating oil groove is an annular groove, which is opened circumferentially along the outer peripheral wall of the outer ring of the double-row self-aligning roller bearing; The lubricating oil holes are provided in multiple ways and are evenly distributed along the circumference of the lubricating oil groove. One end of each lubricating oil hole is connected to the lubricating oil groove, and the other end extends through to the roller raceway of the double-row self-aligning roller bearing.

8. The lubricating sludge discharge device for the small gear bearing seat of a coal mill according to claim 1, characterized in that, The centerline of the lubrication channel is arranged along the vertical centerline of the eye bolt, and the diameter of the lubrication channel is adapted to the diameter of the threaded hole, so that the lubricating grease can be pressed along the lubrication channel to the roller raceway of the double-row self-aligning roller bearing.

9. The lubricating sludge discharge device for the small gear bearing seat of a coal mill according to claim 1, characterized in that, The outer ring of the double-row self-aligning roller bearing is clearance-fitted to the inner wall of the bearing housing, while the inner ring of the double-row self-aligning roller bearing is interference-fitted to the outer circumferential wall of the shaft via a locking sleeve.

10. A method for discharging lubricating sludge from a small gear bearing housing in a coal mill, characterized in that, The lubricating sludge discharge device for the small gear bearing seat of a coal mill as described in any one of claims 1-9 includes the following steps: Remove the eye bolts on the top of the bearing cap, connect the grease injection tool connector to the threaded hole on the bearing cap, and inject lubricating grease into the grease channel. The grease is evenly delivered to the roller raceway through the lubricating oil groove and lubricating oil hole to form a lubricating film. After the lubricating film is formed, loosen the sealing bolt on the drain hole of the cover to discharge the accumulated oil and grease in the bearing housing from the drain hole. After discharge, tighten the sealing bolt to achieve a seal. After the seal is achieved, the eye bolt is screwed back onto the top end face of the bearing cover through the threaded pair to restore the initial structure of the device.

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