DN Factor, also called DN Value, is a number that is used to determine the correct base oil viscosity for the lubrication of various types of bearings. It can also be used to determine if a bearing is the correct choice for use in a given application. It is a product of bearing diameter (D) and speed (N).
10/12/2018 · DN factor = diameter (mm) x RPM (r/min) Plain Bearing. DN factor = diameter shaft (mm) x RPM (r/min) Ball Bearing. DN factor = ((A+B)/2) (mm) x RPM (r/min) Double-row Ball Bearing. DN factor = ((A+B)/2) (mm) x RPM (r/min) Single-row Cylindrical Bearing. DN factor = ((A+B)/2) (mm) x RPM (r/min) x 2: Double-row Cylindrical Bearing, SKF recommends oil lubrication for bearings with a ring centred cage. When SKF high-capacity cylidrical roller bearings are grease lubricated, the nd m value is limited to ? 250 000 mm/min. where. d m: bearing mean diameter [mm] = 0,5 (d + D) n: rotational speed [r/min], In this ideal case the maximum operating inner ring rotation speed is given from the speed factor dN, where dN is the product of the bearing bore (d mm) times the maximum speed (N RPM). Depending on bearing design, dN can have values up to 600,000. The maximum inner ring rotation speed with petroleum oil lubricant, N max RPM, is given for each …
Contact the SKF application engineering service through your local SKF representative if you have any questions, or require any assistance, when using the bearing selection process guidelines or information here and in the product sections. Section navigation. Rolling bearings;, DN (Speed Factor) NLGI # 630, 633, 635-34 to 37°C (-30 to 100°F) 0 – 75,000 1 75,000 – 150,000 2 150,000 – 300,000 2 613, 615, 622, 625-34 to 65°C (0 to 150°F) 0 – 75,000 2 75,000 – 150,000 2 150,000 – 300,000 3 629, 630, 635 37 to 135°C (100 to 275°F) 0 – 75,000 2 75,000 – 150,000 3 150,000 – 300,000 3, The information provided under Principles of bearing selection and application is general and applies to most super-precision bearings. Information specific to one bearing type is provided in the relevant product section: Angular contact ball bearings
