A bearing assembly can comprise: a base member including at least one base ramp; a carriage member including: a first surface defining a bearing channel, the bearing channel configured to receive a plurality of ball bearings and allow recirculating movement of the ball bearings, the bearing channel having a variable depth, wherein the bearing channel having a variable depth is configured to allow the plurality of ball bearings to extend beyond the first surface at a first portion of the bearing channel and extend below the first surface at a second portion of the bearing channel; a second surface opposing the first surface, the second surface including at least one carriage ramp, the carriage ramp configured to engage the at least one base ramp; and a retaining member configured to cover a least a portion of the first surface and retain the ball bearings in the carriage member.

A support and guide device capable of smoothly shifting a moving block configured to move along a guide track from one of a plurality of track rails forming the guide track to another of the plurality of track rails even when clearances are secured at joints between the plurality of track rails. Each of the track rails has auxiliary sliding surfaces formed on both end portions of the each of the plurality of track rails in the longitudinal direction, the auxiliary sliding surfaces formed side by side with a guide surface and being inclined with respect to the guide surface. The moving block includes leading sliding portions each configured to face one of the auxiliary sliding surfaces of the track rail when the moving block reaches one of both end portions of the track rail in the longitudinal direction.