... :ZZ,RS 4,Noise level:Z1,Z2 four row cylindrical roller bearings is in line contact with the raceway, so the ... Lubrication Lubrication Groove &3 Holes in Outer Ring Structure Cylindrical roller bearings N series,NU series,NF series,NUP series Features heavy ... load, high rotation speed Application These bearings are mostly found in middle-sized and large-sized motors, electricity generators, internal ...