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1 bearing vibration quality testing standards
1. Vibration acceleration national standard (commonly known as the Z scale)
The earlier standards to measure the rotation of the bearing vibration acceleration values to determine the bearing quality grade, divided into Z1, Z2, Z3 from low to high three quality grades. Domestic bearing manufacturers are still in use, in order to measure the bearing vibration acceleration values the merits, just simply reflect the bearing fatigue life.
2. Vibration velocity standard (commonly known as the V mark)
Since the original vibration acceleration standard has not been abolished, so that the standard is based on mechanical industry ministerial standards emerge, is the reference to European standards combined with China's actual situation and the need to develop in order to detect bearing vibration velocity divided by the bearing quality level (equivalent to the national standard). Into V, V1, V2, V3, V4 five quality levels. Various ball bearing quality level from low to high as V, V1, V2, V3, V4; roller bearings (cylindrical, conical) quality level from low to high as V, V1, V2, V3 four quality levels. It is based on detecting bearing different frequency bands (low, medium, high) vibration velocity to reflect the quality of the bearing. Bearings can be roughly analyzed whether there geometry problems (such as rims oval), roller / rolling quality problems, quality problems cage, to examine the vibration acceleration than to have a significant bearing quality improvement. Domestic exports to Europe bearing, our military and aerospace industries are in accordance with the standards for bearing quality testing, while testing the quality and resolution of the European bearing counterfeit bearings provide a viable means.
Currently there are two bearing quality testing standard parallel situation, while "Z standard" bearing a high quality level to "V standard" detection may not have a good quality of performance, there is no correspondence between the two. This bearing quality testing is to pay special attention.
(2) in order to detect the vibration measuring instrument bearings
Bearing in operation, ISO2372 standard although they are vibration velocity to determine whether the excessive vibration, but in practice, with special attention to the scene bearing acceleration value changes, mostly bearing damage during the initial presentation of fatigue damage, this can generally be expressed as apparent acceleration increases, along with the development of fatigue, the gradual emergence of vibration velocity and displacement increases, indicating that in bearing fatigue damage. Especially for bearing detection, careful attention to whether the value of unstable vibration swing (recommended analog pointer instrument, you can observe the very obvious), if there is swing, heralded the emergence of unstable vibration signals, acceleration also great, especially the speed while increasing, is likely to exist bearing "playing sets of" fault.
For new equipment, testing and acceptance, although the vibration is very small, in line with national standards, but in the bearing parts appear small amplitude vibration swing phenomenon, eliminate bearing with the problem (playing sets), the most likely bearing geometry problems, such as Bearings Rims oval, rolling through the major axis position, the gap may be due to reduced rolling moment caused by stuck up rolling continue to squeeze, so that sliding friction rolling, rolling each one will appear in this sliding friction , resulting in unstable signal appears. This problem is detected Shanxi 220KW new motor encountered, the disintegration of detectors to detect bearing, proved entirely correct judgment.
Special Note: When checking the bearings, bearing acceleration values must not ignore the changes. Better able to predict the acceleration of early bearing failure.
| Product Model | Inside Diameter | Outside Diameter | Thickness |
| 7216B NSK | 80 | 140 | 26 |
| 7216A NSK | 80 | 140 | 26 |