A bearing assembly includes a first race having an arcuate configuration and a first set of bearing elements. The first set of bearing elements is arranged to dynamically contact the first race and recirculate within the bearing assembly in a first direction. A second race has an arcuate configuration and is removably secured to the first race. A second set of bearing elements is arranged to dynamically contact the second race and recirculate within the bearing assembly in a second direction opposite the first direction.

Spindle units are provided for machining devices, in particular for a lathing spindle unit, center drive assembly or milling spindle unit. The spindle unit comprises: a spindle shaft rotatably supported in a housing, a chucking device disposed at the spindle shaft for clamping a workpiece or a tool, a motor drive connected to the spindle shaft for driving the spindle shaft around a drive axis, a clamping device for clamping the spindle shaft at a freely selectable angular position around the drive axis, wherein the clamping device is disposed between the spindle shaft and a stationary part of the spindle unit, and an actuating device for actuating and/or releasing the clamping device. The clamping device can be axially actuated in the direction of the drive axis such that an axial or substantial axial clamping force acts in the direction of the drive axis with the clamping device being actuated.