초록 ▼

A linear motor system includes first and second linear motors driving a load along spaced-apart supports. A positioning table, or a portion of a machine tool, supported between the first and second linear motors includes a device for varying the position of the table or portion along an axis extendi

A linear motor system includes first and second linear motors driving a load along spaced-apart supports. A positioning table, or a portion of a machine tool, supported between the first and second linear motors includes a device for varying the position of the table or portion along an axis extending between the first and second linear motors. A single motor control system produces a motor drive signal. A proportioning device proportions the portion of the motor drive signal fed to the two motors in a proportion controlled by the position of the table or portion.

대표청구항 ▼

A positioning device comprising: first and second spaced-apart linear motors movable parallel to each other along an X axis; a Y-axis assembly bridging said first and second spaced-apart linear motors; said Y-axis assembly including a workpiece support; means for moving said workpiece support to sel

A positioning device comprising: first and second spaced-apart linear motors movable parallel to each other along an X axis; a Y-axis assembly bridging said first and second spaced-apart linear motors; said Y-axis assembly including a workpiece support; means for moving said workpiece support to selectable positions along a y axis normal to said X axis; means for producing a first control signal responsive to a position of said workpiece support along said Y axis; control signal means for producing a motor control signal; proportioning means responsive to said first control signal for proportioning said motor control signal between said first and second linear motors; said proportioning means including means for producing first and second signals for feeding to said first and second linear motors respectively; said first linear motor including feedback means for producing a feedback signal indicating one of a position and a velocity; said control signal means being responsive to said feedback signal to vary said motor control signal in response thereto, whereby said first linear motor is driven under closed-loop control and said second linear motor is driven under open-loop control in response to a closed-loop control signal produced in response to said feedback signal from said first linear motor.