With the miniaturization and low torque of rotating machinery and equipment, the NSK bearing model used in it has also put forward the requirements of high sealing and low torque at the same time. Meeting this requirement are DDW sealed bearings. Compared with the standard contact seal type DDU bearing, it has the following features: (1) The interference between the main sealing lip and the inner ring of the sealing ring is small, and because the main sealing lip is slender, the pressure of the sealing lip is reduced and the torque is reduced. (2) The main sealing lip is in contact with the outer inclined surface of the inner ring sealing groove, and the grease splashes outward under the action of centrifugal force, so the dustproof performance is excellent. Because the main sealing lip contacts the outer inclined surface of the inner ring sealing groove, the internal pressure of the bearing is not easy to escape from the main sealing lip, so it is not easy to occur the grease leakage phenomenon associated with the internal pressure leakage. NSK currently has bearings with an inner diameter of 10 to 50mm. If you need a larger size bearing, please contact us. The VV standard color of the DDW nitrile rubber seal is green, which is easy to distinguish from the black non-contact seal and the brown DDU standard seal. Fig. 14 is a schematic diagram of a DDW sealed bearing, and Fig. 15 is an example of evaluation results. Test bearing: 4 sets of 6203 grease: Lithium ester grease filled with 45% of the space volume Fig. 15 DDW sealed bearing evaluation test exampleFig. 14 DDW sealed bearing (2) Dustproof performance Rotation speed: 6 700 min-1 radial Load: 147 N{15kgf} Ambient temperature: 100 C Dust amount: 200 g/tester to the occurrence of seizure for more than 50 hours.