How to check for mechanical wear while the machine is still running (without disassembling it)

1. Perform ferrography analysis on the oil to determine the types and concentrations of metals present in it； 2. Monitor the vibration of the bearing; radial vibration can indicate bearing wear ；

I think one can use “seeing,” “listening,” and “touching” to observe mechanical wear. Check: Observe whether the equipment is operating smoothly, whether there is sufficient lubrication, and if there are any oil leaks ； Listen: Check if there are any unusual noises coming from the device ； Touch: Once it is confirmed to be safe, touch the device’s casing to feel its temperature and detect any vibrations. Of course, it is safer and faster if there are devices such as vibration meters and thermometers available.

1. Monitor the temperature rise of the measuring equipment; excessively high temperatures certainly lead to severe wear； 2. Listen for any unusual noises; if there is a ‘hissing’ sound, the equipment is definitely severely worn out ； (It’s best to use a listening rod when listening.) 3. Measure the vibration; if the amplitude is too high, stop the machine for inspection. This is usually caused by loose foundation screws, imbalance in the equipment, or severe wear and tear of the equipment.

1. The best method is to perform ferrography analysis on the oil, but this is not possible when using grease lubrication. 2. Analyze it through the process materials of your device. 3. It’s about listening to the sounds; if there are sharp metallic grinding noises, then it’s definitely because the components are worn out. This post was last edited by zhangya*ong on 2009-3-5 11:42]

1. It can be determined based on the operational status data of the equipment (vibration, temperature, noise), with inspections being carried out using online or offline devices； 2. It can be determined based on process parameters (flow rate, pressure) ；

The simple methods used for condition monitoring mainly include auscultation, palpation, and observation. 1. Auscultation: When the equipment is operating properly, the sounds produced always have a certain rhythm and pattern. By becoming familiar with and mastering these normal melodies and rhythms, one can use their auditory senses to detect any abnormal noises such as heavy, noisy, strange, or chaotic sounds coming from the equipment, and thus identify potential issues like looseness, collisions, or imbalance within the equipment. By tapping the part with a hammer and listening for any cracking noises, it is possible to determine whether cracks have formed. An electronic stethoscope is a vibration acceleration sensor. It converts the vibration conditions of the equipment into electrical signals and amplifies them; workers use headphones to listen to the vibrations of the operating equipment, thereby enabling qualitative measurement of those sounds. By measuring the signals at the same measurement point at different times, under the same rotational speed and under the same operating conditions, and comparing them, it is possible to determine whether there is a fault in the equipment. When crisp and high-pitched noises are heard from the headphones, it indicates a high vibration frequency; usually, this is caused by local defects or tiny cracks in components that are relatively small in size but high in strength. When the headphones produce a muffled, low-frequency noise, it indicates that the vibration frequency is low; generally, this is due to large cracks or defects in parts that are relatively large in size and have relatively low strength. When the noise coming from the headphones increases compared to normal, it indicates that a fault is developing; the louder the sound, the more severe the fault. When the noise coming from the headphones appears in a chaotic and intermittent manner, it indicates that a component or part is loose. 2. Touch sensing method: The tactile sense of the human hand can be used to monitor changes in the equipment’s temperature, vibration, and clearance. The nerve fibers in the hands are sensitive to temperature, allowing them to detect temperatures down to 80°C with relatively high accuracy. When the temperature of the component is around 0°C, it feels icy to the touch; prolonged contact can cause a piercing pain. At around 10°C, it feels cool to the touch, but it is generally tolerable. At around 20°C, it feels slightly cool to the touch; as contact time increases, it gradually becomes warmer. At around 30°C, it feels slightly warm to the touch, providing a comfortable sensation. At around 40°C, it feels warm to the touch, with a slight burning sensation. At around 50°C, it feels quite hot to the touch; if one presses with the palm for an extended period, sweating will occur. At around 60°C, it feels very hot to the touch, but it is generally tolerable for up to 10 seconds. At around 70°C, it feels scorching hot to the touch; one can generally only tolerate it for about 3 seconds, and the area touched by the hand turns red very quickly. When touching, touch it first and then feel it more carefully to estimate the temperature rise of the component. By shaking the component by hand, it is possible to sense the gap size of 0.1mm–0.3mm. By touching the components with your hand, you can sense changes in the intensity of vibration and whether shocks are generated, as well as the movement of the sliding plate. Using a thermometer equipped with a surface thermocouple probe to measure the surface temperature of components such as rolling bearings, sliding bearings, spindle housings, and motors offers the advantages of rapid identification of the location of thermal abnormalities, accurate data, and a convenient measurement process. 3. Observation method: The human eye can be used to check whether there is any looseness, cracks, or other damage in the components of the equipment ； It is possible to check whether the lubrication is proper, as well as to detect any signs of dry friction or leaks ； It is possible to examine the quantity, size, and characteristics of metal particles in the tank sediment in order to assess the wear level of related components ； It is possible to monitor whether the device is moving normally and if there are any abnormal phenomena ； It is possible to view the various gauges installed on the device, which indicate its operating status, in order to understand how the data changes. By using measurement tools and by directly observing the surface condition, it is possible to assess the quality of the product and determine the device’s operating condition. By conducting a comprehensive analysis of the various observed information, it is possible to determine whether there is a fault in the equipment, identify the location of the fault, assess the severity of the fault, and determine its cause. A simple method for monitoring wear conditions by using instruments to observe the wear particles collected from the equipment’s lubricant is the magnetic plug method. Its principle involves inserting a magnetic plug into the lubricating oil to collect the iron particles generated by wear; by using a reading microscope or simply observing with the naked eye, the size, quantity, and shape of these particles are examined in order to determine the degree of wear on the surface of mechanical parts. The magnetic plug method can be used to observe the larger size of abrasive particles that appear in the later stages of wear of mechanical parts. During inspection, if small abrasive particles are found in small quantities, it indicates that the equipment is operating properly ； If large abrasive particles are detected, it is necessary to pay close attention and closely monitor the operating condition of the equipment ； If large particles are detected repeatedly in a row, it is a sign that a failure is imminent; the machine should be stopped immediately for inspection to identify and resolve the issue

Are there any abnormal changes in the process parameters, such as pressure and flow rate?； Make judgments using the five senses, such as checking whether the temperature is abnormal or if there is noise from the device, and sensing through touch whether vibrations have increased ； With the help of measuring instruments, such as thermometers and vibration meters, etc ； Physical and chemical analysis, such as oil analysis, etc