The self-aligning roller bearings used in agricultural machinery play a crucial role in supporting rotating components, transmitting power, and reducing friction. Their maintenance quality directly affects the efficiency and reliability of agricultural machinery. The following are detailed maintenance methods for self-aligning roller bearings used in agricultural machinery, combined with the working characteristics and common problems of agricultural machinery, providing actionable solutions:
1. Daily inspection and cleaning
Appearance inspection
Operating status: Before and after agricultural machinery operation, observe whether there are abnormal vibrations, noises, or heating phenomena in the bearing parts. If the bearing temperature exceeds the ambient temperature by 40 ℃ or the surface becomes hot, the machine should be stopped immediately for inspection.
Sealing: Check whether the bearing sealing ring is intact, whether there is oil leakage or dust intrusion.
. If the sealing ring is damaged, it should be replaced in a timely manner to prevent impurities from entering the interior of the bearing. Lubrication status: Check whether the lubricating grease is sufficient, whether the surface is dry or discolored (such as turning black or clumping), which may be a signal of grease aging or contamination.Cleaning treatment
Removing impurities: Use a soft bristled brush or compressed air to remove dirt, straw, and other debris from the surface of the bearing, to prevent impurities from entering the interior of the bearing and accelerating wear.
. Cleaning cycle: For agricultural machinery (such as harvesters and tractors) that operate in muddy and dusty environments for a long time, it is recommended to clean the bearings every 50 hours of operation; It can be extended to 100 hours in a dry environment.2. Lubrication and Maintenance
Lubricating grease selection
Type matching: Select lubricating grease according to the working conditions of the agricultural machinery.
. For example, in high-temperature environments (such as summer field work), lithium based lubricants with high drop points and high temperature resistance should be selected; Choose calcium based or composite aluminum based lubricating grease with strong water resistance in humid environments (such as paddy field operations). Performance requirements: Priority should be given to lubricating grease with extreme pressure anti-wear, anti-oxidation, and anti rust properties to extend the bearing life.Lubrication cycle and quantity
Cycle: New bearings need to be lubricated after 50 hours of initial operation, and then every 200-300 hours or one working season.
. If the agricultural machinery frequently starts and stops or experiences large load fluctuations, the lubrication cycle needs to be shortened.Filling amount: The filling amount should be 1/3-1/2 of the internal space of the bearing. Excessive filling can cause grease to overflow and absorb dust, which can accelerate wear.
.Lubrication method
Manual filling: Use a grease gun to add lubricating grease through the oil nozzle on the bearing seat. When filling, slowly rotate the bearing to evenly distribute the lubricating grease.
.Centralized lubrication system: For large agricultural machinery (such as combine harvesters), the centralized lubrication system can be used to automatically add oil at regular intervals, and the system pipelines need to be checked regularly for blockages.
.III. Installation and disassembly specifications
Preparation before installation
Cleaning the shaft and holes: Thoroughly clean the shaft and bearing seat holes with gasoline or cleaning agent, remove burrs, rust, and oil stains, and ensure a smooth mating surface.
.Check the fit size: Measure the shaft diameter and bearing inner diameter, bearing seat aperture and bearing outer diameter, and confirm that the interference or clearance meets the design requirements (usually the interference is 0.01-0.03mm).
.Installation method
Heating installation: For bearings with interference fit, oil bath heating (80-100 ℃) or induction heater can be used to heat the inner ring of the bearing, causing it to expand and quickly fit onto the shaft to avoid direct impact damage to the bearing.
.Cold installation precautions: If cold installation is used, dry ice or liquid nitrogen should be used to cool the inner ring of the bearing, but the cooling time should be controlled to prevent excessive shrinkage of the inner ring and loose fit.
.Disassembly Tips
Special Tools: Use a puller or hydraulic disassembler to disassemble the bearing, avoiding directly hitting the outer or inner ring of the bearing with a hammer to prevent deformation of the raceway.
.Heating assistance: For tightly fitted bearings, oxygen acetylene flame can be used to locally heat the outer ring of the bearing (pay attention to uniform heating), making it easy to disassemble after expansion.
.IV. Operation Monitoring and Fault Prevention
Temperature Monitoring
Infrared thermometer: Regularly use an infrared thermometer to detect the bearing temperature. If the temperature continues to rise (such as exceeding 80 ℃), it may be a signal of insufficient lubrication, excessive load, or bearing damage.
.Temperature alarm device: For critical parts (such as engine main bearings), temperature sensors can be installed and alarm thresholds can be set to achieve real-time monitoring.
.Vibration analysis
Simple judgment: Touch the bearing seat with your hand to feel the intensity of the vibration. If the vibration intensifies significantly, it may be due to damage to the bearing raceway or a broken cage.
. Professional testing: Use a vibration analyzer to detect the vibration frequency and amplitude of bearings, and determine the type of fault (such as inner ring fault, outer ring fault, or rolling element fault) through frequency spectrum analysis.Load Management
Avoid Overloading: Control the load according to the design parameters of the agricultural machinery to avoid premature bearing failure caused by long-term overload operation.
.Uniform force distribution: Adjust the working posture of the agricultural machinery (such as the height of the harvester cutting platform) to ensure even bearing force on the shaft and reduce edge stress caused by unbalanced load.
.Fifth, Storage and Transportation Protection
Short term Storage
Cleaning and Drying: Store bearings in a clean and dry room, avoiding contact with corrosive substances such as acids and alkalis.
. Rust prevention treatment: Apply a thin layer of rust proof oil on the surface of the bearing and seal it with plastic film. Long term storageRegular rotation: Rotate the bearing 1/4 turn every 3 months to prevent indentation on the raceway due to long-term inactivity.
. Environmental control: The storage temperature should be controlled between 5-35 ℃, and the relative humidity should not exceed 60% to avoid lubricating grease deterioration caused by high temperature and humidity.Transportation protection
Fixed packaging: Use wooden or cardboard boxes to secure the bearings to avoid shaking and collision during transportation.
. Moisture prevention measures: Place desiccants inside the packaging to prevent moisture and rust during transportation.VI. Common Fault Handling
Bearing Overheating
Causes: Insufficient lubrication, deteriorated grease, excessive load, or tight installation.
.Treatment: Add or replace lubricating grease, check if the load exceeds the standard, and readjust the bearing clearance.
.Abnormal noise
Causes: damage to rolling elements, breakage of retaining frames, or invasion of impurities.
.Treatment: Stop the machine to check the bearings, replace damaged parts, clean the bearings and re lubricate them.
.Axial movement
Reason: Loose fit between the inner ring of the bearing and the shaft or loose fit between the outer ring and the bearing seat.
.Processing: Reprocess the shaft or bearing seat to ensure that the fit size meets the requirements, or fix the bearing with a locking nut.
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