Measured rotational speed For motor bearings with an inner diameter of ≤60mm, the set rotational speed is 1800r/min; for bearings with an inner diameter of 65mm to 120mm, the set rotational speed is 900r/min. 6 Vibration level 6.1 Vibration (speed) value of deep groove ball bearing Deep groove ball bearings with 0, 2, 3 sets of clearance specified by T4606-2006. V group is the basic requirement for general bearing vibration (speed), V is not marked on the bearing; V1, V2, V3, V4 groups are suitable for bearings with vibration (speed) requirements. 6.1.3 For deep groove ball bearings with an inner diameter of 3mm to 60mm, the vibration (velocity) of a single bearing of different groups shall meet the requirements in Table 27. For deep groove ball bearings with an inner diameter of 65mm to 120mm, the vibration (velocity) of a single bearing of different groups should meet the requirements in Table 28. 6.2.1 Measured rotational speed of deep groove ball bearing vibration acceleration level For bearings with an inner diameter of ≤60mm, the set rotational speed is 1500r/min; for bearings with an inner diameter of 60mm to 120mm, the set rotational speed is 1000r/min. The external dimensions conform to the 0, 2, and 3 diameter series in GB/T276-1994, the nominal inner diameter is 3mm to 120mm, and the radial clearance conforms to the deep groove ball bearings with the 0, 2, and 3 groups of clearance in GB/T4606-2006. 6.2.3 Measured value: 6.2.2 Scope of application: See Table 29 and Table 30 for the vibration (acceleration) limits of deep groove ball bearings.