As one of the commonly used machines in feed processing machinery, feed grinders often experience bearing overheating and excessive bearing temperature rise during use. The temperature rise reflects, to a certain extent, the assembly quality of the feed grinder and the scientific rationality of the user's use of the machine. Excessive bearing temperature rise will accelerate bearing wear, cause damage to the spindle, and seriously affect the reliability and safety of the whole machine. The main factors affecting the feed grinder bearing temperature rise are: bearing quality, spindle speed, assembly quality, lubrication, and usage.
1. Bearing quality
Feed mills generally use rolling bearings, and the quality of the bearing material has a very important impact on the bearing temperature rise. When the machine is running, the inner ring of the bearing is deformed due to force, causing the bracket to deform or the clearance to change, which will make the bearing inflexible and the bearing temperature rise too high. Therefore, it is necessary to ensure that the bearings of the purchased feed mill are qualified products. It is best to choose a feed mill produced by a regular manufacturer.
2 Spindle speed
The speed of the main shaft of the feed grinder is generally above 4500r/min. The main shaft transmits the power of the motor to the hammers or claws on the rotor disc. The working principle of the feed grinder is to crush the feed through the high-speed running hammers or claws to complete the crushing work. The bearing is a component that supports the high-speed operation of the main shaft. The faster the speed, the higher the bearing temperature rise. Therefore, when using the feed grinder, you should choose the matching power according to the requirements of the manual.
3. Assembly quality
Assembly quality is an important factor affecting the bearing temperature rise of the feed mill. If the bearing cover and the shaft are too tight, or if the bearing and the main shaft are too tight or too loose, the bearing will overheat. During the operation of the equipment, once the bearing makes a friction sound and swings obviously, the machine should be stopped to remove the bearing, trim the friction part, and then reassemble it as required. The tightness of the transmission belt during assembly and whether the rotor is balanced will affect the temperature rise of the bearing. The two bearings on which the rotor is installed are not concentric. That is, the coaxiality of the two journal positions of the bearing installed on the rotor shaft is not enough, and the V-groove of the rotor pulley is not aligned with the V-groove of the power (motor) pulley, which will cause the bearing to be impacted by unstable loads, thereby causing the bearing to overheat. Therefore, a rotor balancing test is required before assembly. Before using the feed mill, check whether the fastening screws are loose, adjust the tightness of the conveyor belt, especially the fastening of high-speed running parts such as claws or hammers must be safe and reliable. If there is an abnormal sound when starting the machine, the machine should be stopped immediately to eliminate the fault to avoid premature damage to the bearing and main shaft and affect the service life of the machine.
4 Lubrication
Too much, too little or aging of lubricating grease in the bearing of the feed grinder can easily cause the bearing temperature to rise too high. If there is too much lubricating grease in the bearing, eddy currents will be generated. Friction increases and the bearing heat dissipation is poor, causing the bearing temperature to rise sharply; too little lubricating grease or the use of cheap and low-quality lubricating grease can easily cause poor bearing lubrication effect; debris entering the bearing, if not cleaned up in time, will increase friction and cause the bearing temperature to rise too high. Therefore, before using the grinder each time, you should check whether the amount of lubricating grease in the bearing is appropriate, whether it is aging and deteriorating, and add or replace it in time. After the grinder has been working for a period of time, the bearing should be disassembled and cleaned.
5 Usage
The main reasons for the excessive bearing temperature rise caused by the user's use are: feeding too much feed; uneven feeding amount, resulting in unstable load; feeding feed with high humidity; starting the machine immediately to operate, etc. Therefore, it is not advisable to feed too much or too wet feed, and the feeding amount should be uniform. Feed mills generally use rolling bearings. The initial temperature of the bearings is relatively high when they start. After running for a period of time, the bearing temperature gradually decreases and reaches a stable value. This is because the load of the machine is unstable when the rolling bearings start to run. Therefore, the feed mill must be started and run idle for a few minutes before the crushing operation can be carried out. After the feeding is completed, the crusher should continue to run for a few minutes, and then stop after all the materials in the crushing chamber are crushed and discharged. The above content summarizes that the bearing quality, spindle speed, assembly quality, lubrication and usage are the main factors affecting the bearing temperature rise of the feed mill, which provides a reference for users to judge the abnormality of the bearing temperature rise. Users should pay attention to the changes in the bearing temperature rise when using the feed mill, and correctly judge the cause and deal with it in time when abnormalities occur.
