1. Listen to the sound
- Normal sound characteristics: When the concrete trowel is running, the normal sound of the bearing is a smooth and slight "buzzing" sound. This sound should be continuous and uniform, without sharp noises, knocks or irregular changes. For example, when the trowel is running at normal speed on a flat concrete surface, the sound of the bearing should be clearly distinguishable above the background noise, but not too harsh.
- Abnormal sound judgment: If you hear a "squeaking", "clicking" or sharp "hissing" sound from the bearing, it usually means that there is a problem with the bearing. The "squeaking" sound may be caused by the wear of the balls or raceways inside the bearing, resulting in an uneven surface, friction and collision during operation; the "clicking" sound may be caused by foreign matter entering the bearing, hindering the normal rolling of the balls; the sharp "hissing" sound may be caused by poor bearing lubrication and increased friction between the balls and raceways.
2. Observe temperature changes
- Normal temperature range: After the trowel has been running normally for a period of time (for example, 30-60 minutes of continuous operation), touch the area near the bearing seat with your hand (be careful to avoid touching moving parts), and it should feel warm but not hot. Generally speaking, the normal operating temperature of the bearing is usually around 40℃-70℃, and the specific temperature may vary slightly depending on factors such as the bearing specifications, load and operating environment.
- Abnormal temperature: If the bearing seat feels very hot when touched, which is significantly higher than the normal temperature range, this may be a sign of bearing failure. Excessive temperature may be due to excessive friction inside the bearing, caused by insufficient lubrication, too tight bearing assembly or excessive load. For example, when the trowel blade of the trowel machine is subject to greater resistance (such as uneven concrete surface or hard lumps), the load on the bearing increases. If the lubrication is poor at this time, it is easy to cause the bearing temperature to rise sharply.
3. Check vibration
- Normal vibration level: When the trowel machine is running, the normal vibration of the bearing is very small and almost imperceptible. You can gently place your hand on the body of the trowel (near the bearing) to feel the vibration. Under normal circumstances, only slight and uniform vibrations will be felt, which are normal vibrations caused by the operation of the trowel itself and the contact with the ground.
- Abnormal vibration judgment: If you feel obvious and irregular vibrations, especially sudden changes in vibration frequency and amplitude, this may be a sign of bearing damage. For example, when the ball of the bearing is damaged or the outer ring of the bearing is cracked, it will cause the rotating parts to lose balance, causing the trowel to vibrate more. This vibration will not only affect the troweling effect, but may also further damage other parts.
4. Check the lubrication condition
- Observe the grease status: When checking the bearing, pay attention to the grease of the bearing. Under normal circumstances, the grease should be evenly distributed inside and around the bearing, and the color and texture remain relatively stable. If the grease is found to be black, dry, or there are obvious impurities mixed in, this may affect the lubrication effect of the bearing. For example, when the grease turns black, it may be because the wear particles generated during the operation of the bearing are mixed in, resulting in a decrease in lubrication performance.
- Grease leak check: Also check for grease leaks. If you see grease seeping around the bearing seat, this could be due to a damaged seal or too much grease. Grease leaks are not only wasteful, but can also contaminate the concrete surface and cause the bearing to fail due to insufficient lubrication.