Abstract: A double-row angular-contact antifriction bearing including an outer bearing ring, and an inner bearing ring and rolling elements between the bearing rings in two rows next to one another on raceways of the bearing rings. A bearing cage for the rolling elements. The inner bearing ring is axially split and is of two individual rings which are connected and between which a distance ring defines axial prestress between the rolling elements of the both rows. The distance ring between the individual rings of the axially split inner ring is a connecting element of the individual rings.

Abstract: A ball-bearing unit for a bearing of a deep-drilling apparatus having bearing races made from steel with balls disposed therebetween. Contaminated drilling medium passes into the space between the bearing races. Load-bearing balls made from ceramic alternate with separating balls of smaller diameter made from steel between the bearing races to extend significantly the service life of the ball-bearing unit.

Abstract: A double-row angular-contact antifriction bearing including an outer bearing ring, and an inner bearing ring and rolling elements between the bearing rings in two rows next to one another on raceways of the bearing rings. A bearing cage for the rolling elements. The inner bearing ring is axially split and is of two individual rings which are connected and between which a distance ring defines axial prestress between the rolling elements of the both rows. The distance ring between the individual rings of the axially split inner ring is a connecting element of the individual rings.

Abstract: A ball-bearing unit for a bearing of a deep-drilling apparatus having bearing races made from steel with balls disposed therebetween. Contaminated drilling medium passes into the space between the bearing races. Load-bearing balls made from ceramic alternate with separating balls of smaller diameter made from steel between the bearing races to extend significantly the service life of the ball-bearing unit.

Abstract: A large antifriction bearing, wherein one of the inner ring parts or the outer ring parts are provided with axially extending, wide toothing. At least one or both of the inner and outer ring parts is divided into cooperating parts through the axis of the bearing. Each set of axially adjacent cooperating ring parts is in turn divided into circumferential segments, and the segments are circumferentially offset. The offset axially neighboring segments of cooperating ring parts are fastened together. One of the rings has its ring parts shaped for defining a U-shape in cross-section. The other ring has its ring parts shaped for defining a projecting portion that projects between the arms of the U-shape. The rolling elements of the bearing are disposed between the insides of the arms of the U-shaped part and the projection from the other part. Preferably the ring part having the teeth is U-shaped, although the other ring part may be U-shaped.