Linear motion carriage system and method with bearings preloaded by inclined linear motor with high attractive force

A system comprised of a linear motion fixed bearing rail, a carriage movable along the rail, and linear motion bearings disposed therebetween to provide five degrees of stiffness for the carriage, and a linear electric motor having two magnetically attractive parts carried respectively by the rail and carriage and oriented with respect to the bearings such that the attractive magnetic force between the two parts of the linear electric motor acts to preload all the bearings, wherein the bearings run on three opposing carriage and rail bearing surfaces, two of which are parallel, and with the third orthogonal to the first two;

• and wherein the linear electric motor is oriented at an angle of about 25 degrees with respect to the parallel bearing surfaces.

A system comprised of a linear motion fixed bearing rail and a plurality of fluid bearings therebetween, a carriage moveable thereover, the bearings being distributed to run on three opposing carriage and rail bearing surfaces, two of which are parallel, and the third of which is orthogonal to the first two, a linear electric motor forcer, a cooperative linear electric motor magnet track, and a trench in the rail disposed at an angle to the bearing surfaces into which the linear electric motor magnet track is fastened, the motor forcer being mounted to the opposing carriage surface in a correspondingly angled groove, such that when the carriage is supported by its bearings and allowed to move along the rail, the attractive force between the motor forcer and the magnet track keeps the bearings preloaded and thus enables the carriage to move with a high degree of stiffness in five degrees of freedom, while being free to move along the rail in the remaining degree of freedom as controlled by the linear electric motor.

A method of preloading linear motion bearings disposed between opposing fixed and movable surfaces each comprising a pair of orthogonal planar surfaces, that comprises, positioning a permanent magnet linear electric coil motor with a high attractive force between the coils and a magnet, upon and at an acute angle incline to the planar surfaces, such that the attractive force creates a preload force on each of the bearings, wherein one of the pair of orthogonal planar surfaces comprises top and side L-shaped wall surfaces movable over the other of the pair of orthogonal planar surfaces which constitute the top surface and side surface of a rail along and over which the carriage is moved and wherein the electric motor coils are fixed inside the top carriage wall surface to move with the carriage, and the magnet extends as a track fixed to the top surface of the rail, with the track and coils tilted at said acute angle to the planar top surfaces, and wherein the track extends in a trough along the rail and the coils are recessed in the inside of the top carriage wall.