GB Standard of Vibration Acceleration (known as Z Standard)
This standard is to determine the bearing quality grades by testing the vibration acceleration value when the bearing is running. There are three quality grades, from low to high, separately Z1, Z2, Z3. Presently, the national bearing manufacturers are still using this standard, but this standard can only reflect the fatigue life of the bearing.
Vibration Velocity Standard (known as V standard)
Because the vibration acceleration standard has not been abolished, so this standard is present in the form of ministerial standard of mechanical industry and was formulated by referring to European standard and combining the actual condition of our country. It is to determine the quality grades of bearing by testing the vibration velocity of bearing (equal to national standard). It has five quality grades: V, V1, V2, V3, V4. As for the ball bearing, the quality grades are separately V, V1, V2, V3, V4, from low to high; as for the roll bearing (cylinder, taper), there are four quality grades, separately V, V1, V2, V3, from low to high.
Presently, both standard are being used in bearing quality detection. For the bearing that gets a high grade in “Z standard”, it may not have good quality performance when it is tested by “standard V”. There is no corresponding relationship between these two standards, which should be paid attention during bearing quality detection.
Source SKET BEARING
