NSK BSN4075 DDUDTHP3 = 2 pcs. Schrägkugellager (40x75x68)

As an axial angular contact ball bearing, this bearing carries high axial loads at elevated speeds, e.g. for ball screws. At 40x75x68 mm and a unit weight of 1.34 kg, the installation envelope is fixed; further technical details are held in the specification table. A contact seal on both sides closes this axially loaded ball arrangement into a ready-to-mount unit and retains the grease fill at the feed axis.

The contact angle of the ball row deflects the load line at an angle to the bearing axis and delivers the high axial capacity and stiffness for which this design is used on ball screws and feed axes; that stiffness is only established once the adjusted set is preloaded. The contact seal on both sides bears against a counterface and closes the rolling chamber against chips, coolant and fine dust — media that are permanently present at a machining tool and would overwhelm non-contact screening.

The sealing contact produces an additional frictional torque and positions the permissible speed below that of the open version; in return the grease fill remains in the bearing over its service life and relubrication is not required within the intended operating window. Standard bearing steel is through-hardened and provides raceway hardness and dimensional stability at normal operating temperatures. For the design, axial force, preload, speed and the contamination level of the environment should be assessed together.