Integrated micro actuator and LVDT for high precision position measurements

An LVDT assembly, comprising:

• a housing, having a cylindrical shape, having first internal screw threads;
• a top portion, having screw threads, said top portion screwed into said first internal screw threads,
• said housing having surfaces forming a first internal channel, said first internal channel attached to said first internal screw threads,
• a primary coil, wound around said first internal channel of said housing, around a central axis of said housing;
• said housing having a second pair of channels, concentric to the first internal channel, and connected to a portion of the housing that does not move as the first internal channel is moved;
• a secondary coil, having first and second parts, said secondary coil wound respectively on said pair of channels, coaxially to said primary coil,
• and located so that said primary coil and said secondary coil moves along said central axis, relative to one another in a substantially parallel direction;
• said top portion tightened to said screw threads to preload the assembly,
• a first electrical connection to said primary coil, extending through said housing;
• and
• a second electrical connection to said secondary coil, extending through said housing.