A device for guiding a shaft in an oscillating movement about a center of
rotation situated on the axis of the shaft comprises a ball-and-socket
bearing and a ball bearing mounted one inside the other between the shaft
and a fixed support. The ball-and-socket bearing comprises a
ball-and-socket joint with an outer convex surface in a portion of a
sphere forming the inner race of the bearing, and two rings of balls that
are arranged between the ball-and-socket joint and two superposed outer
races of the bearing and that are guided in semicylindrical annular slots
or grooves of the races.