Wide bandwidth linear motor system

An assembly for a linear motor for driving a shaft, said assembly comprising:

• means for supporting a coil, said means for supporting including a plurality of portions of a cylindrical member, each portion of said plurality being for supporting said coil, each portion of said plurality being separated from the remaining portions of said plurality so that no part of said cylindrical member connects any two of said portions;
• and
• means for connecting said each portion of said plurality to said shaft, said means for connecting comprising a plurality of rib members, said rib members of said plurality corresponding to said portions on a one-to-one basis, each of said rib members having a first end thereof connected to its corresponding portions;
• so that mechanical resonance of said assembly in operation is suppressed.

A linear motor system comprising:

• a linear motor for driving a shaft connected to a load with linear motion along the axis of the shaft, said linear motor comprising
• a movable coil assembly including a plurality of portions of a cylindrical member coaxial with said shaft, each portion of said plurality being for supporting said coil, each portion of said plurality being separated from the remaining portion of said plurality so that no part of said cylindrical member connects any two of said portions, means for connecting said each portion of said plurality to said shaft, said means for connecting comprising a plurality of connecting members, said connecting members corresponding to said portions on a one-to-one basis, each of said connecting members having a first end connected to its corresponding portion, a coil comprising multiple turns of a conductor wound circumferentially around said plurality of portions;
• means for producing a radial magnetic field intersecting said coil;
• amplifier means for supplying an energizing current to said coil so as to produce linear movement of said coil assembly and said shaft;
• position sensing means for sensing the position of said shaft along said axis and producing a position feedback signal representative of said shaft position;
• and
• adding means for comparing said position feedback signal with a position command signal representing a desired shaft position and providing an error signal to said amplifier means for energizing said motor and reducing said error signal.