SKF Bearing Processing Standards

(1) Temperature conditions during measurement
The ambient temperature during measurement is specified as 20°C. The temperatures of bearings, gauge blocks, standard parts and measuring instruments must all be the same. The above method of placing them on the same metal plate can achieve the necessary temperature balance as quickly as possible, otherwise It takes hours or even days to achieve this balance.
In order to obtain correct measurement results, foreign countries rely on mechanization of measurement to avoid human hands coming into contact with these objects, or wear insulating gloves to operate.
(2) Regulations on measurement area
For the measurement of the inner diameter or outer diameter of SKF bearings, domestic regulations stipulate that the measurement is within an area with one maximum chamfer coordinate on the south end surface of the ferrule, while foreign regulations generally require that the measurement is within an area with twice the chamfer coordinates on both end surfaces of the ferrule. Measure within.
(3) Regulations on dimensional standards
When using the comparative measurement method to measure bearing dimensional tolerances, it is stipulated that gauge blocks or standard parts should be used as the dimensional benchmark for comparative measurements. The gauge blocks must comply with the provisions of the standard JB/T1078 “Gage Blocks”, and the standard parts must comply with the requirements of the manufacturer’s competent department. Provisions.
(4) Provisions on measuring instruments
The instrument used for measurement must be calibrated and have an accuracy and amplification ratio suitable for the bearing being measured.
(5) Allowable measurement error
In principle, the measurement error can be allowed to be less than 10% of the tolerance.
(6) Probe radius and measuring gauge pressure
In order to reduce the measurement error, we must strive to reduce the pressure-measuring force of the measuring meter and increase the curvature radius of the probe within the possible range.
When measuring the inner diameter and outer diameter of the bearing, the measuring force and curvature radius of the probe can be selected as a reference.
(7) Spindle used for measurement
When measuring items such as Kia, Kea and Sd of SKF bearings, for cylindrical bore bearings, the taper of the taper mandrel used is in principle stipulated to be 1/5000 to l/10000. For tapered bore uranium bearings, the basic taper of the taper mandrel used is The regulation is 1/12.
(8) Provisions for measuring load
When measuring Kia, Kea, Sia, Sea and other items, the necessary measurement load needs to be applied to keep the rolling elements and ferrules in normal contact positions to obtain stable measurement values.
(9) Provisions on measuring datum plane
For general bearings, the non-printed end surface of the ferrule is taken as the datum surface during measurement. For angular contact ball bearings and tapered roller bearings, the end surface that bears the thrust load is taken as the datum surface.