Motor system, motor, and robot arm device comprising the same

A motor system, comprising a motor having:

• a rack member provided with a structure on a surface thereof, said structure having a periodic arrangement of a gear element in at least one direction;
• a tooth member accommodating a set of multiple actuators arranged for one direction of said at least one direction, each of said actuators comprising an engaging element shaped for engaging said gear element and a drive unit for driving said engaging element to move back and forth with respect to said periodic structure, wherein the engaging element engages said gear element at least during part of the movement towards the gear element to cause a relative movement between said rack member and said tooth member in said one direction of said at least one direction, and wherein each of said actuators is positioned spaced apart to engage said periodic structure at a different reduced phase thereof;
• a control unit configured to periodically control each drive unit of each actuator in the set of actuators to operate in a time-shifted manner with respect to each other;
• wherein the arrangement of the gear element is periodic in at least two dimensions, and wherein said actuators further comprise a set of actuators for each of said at least two dimensions.