Multi-degree-of-freedom actuator and stage device
A multi-degree-of-freedom actuator includes a movable element having a plurality of permanent magnets, and a stator including a stator core and a plurality of coils. The permanent magnets are arranged in the X direction such that the number P of poles is an even number of two or more. The coils are of two types: X-direction driving coil and Z-direction driving coil. The Z-direction driving coils the number of which is P are disposed at positions opposite to magnetic poles of the permanent magnets. The X-direction driving coil or coils the number of which is P/2 are each disposed at a position opposite to an intermediate point between two adjacent ones of the magnetic poles of the permanent magnets.
1. A multi-degree-of-freedom actuator comprising:
a movable element having a first permanent magnet and a second permanent magnet arranged in an X-direction; and
a stator including a stator core and a plurality of coils, the plurality of coils comprising:
an X-direction driving coil to relatively drive the movable element in the X-direction and having a first coil side and a second coil side opposite to the first coil side; and
a first Z-direction driving coil and a second Z-direction driving coil to relatively drive the movable element in a Z-direction, each of the first and second Z-direction driving coils having an air core around which a wire is wound and provided such that the air core faces a magnet pole of each of the first and second permanent magnets, the first coil side being provided at the air core of the first Z-direction driving coil, the second coil side being provided at the air core of the second Z-direction driving coil.
2. The multi-degree-of-freedom actuator according to claim 1 , wherein the first coil side is inserted in the air core of the first Z-direction driving coil and the second coil side is inserted in the air core of the second Z-direction driving coil.
3. The multi-degree-of-freedom actuator according to claim 1 , further comprising:
teeth integrally formed in the stator core, wherein the teeth are inserted into the air cores of the first and second Z-direction driving coils, and wherein the first and second coil sides are disposed at ends of the teeth.
4. The multi-degree-of-freedom actuator according to claim 1 , further comprising:
an X-direction amplifier connected to the X-direction driving coil to drive the X-direction driving coil; and
a Z-direction amplifier connected to the first and second Z-direction driving coils to drive the first and second Z-direction driving coils, wherein the X-direction amplifier and the Z-direction amplifier operate independently of one another.
5. The multi-degree-of-freedom actuator according to claim 1 , further comprising:
an X-direction amplifier connected to the X-direction driving coil to drive the X-direction driving coil;
a first Z-direction amplifier connected to the first Z-direction driving coil to drive the first Z-direction driving coil; and
a second Z-direction amplifier connected to the second Z-direction driving coil to drive the second Z-direction driving coil, wherein the X-direction amplifier, the first Z-direction amplifier and the second Z-direction amplifier operate independently of one another.
6. A stage device comprising:
at least three multi-degree-of-freedom actuators each comprising:
a movable element having a first permanent magnet and a second permanent magnet arranged in an X-direction; and
a stator including a stator core and a plurality of coils, the plurality of coils comprising:
an X-direction driving coil to relatively drive the movable element in the X-direction and having a first coil side and a second coil side opposite to the first coil side; and
a first Z-direction driving coil and a second Z-direction driving coil to relatively drive the movable element in a Z-direction, each of the first and second Z-direction driving coils having an air core around which a wire is wound and provided such that the air core faces a magnet pole of each of the first and second permanent magnets, the first coil side being provided at the air core of the first Z-direction driving coil, the second coil side being provided at the air core of the second Z-direction driving coil; and
a levitating element moved with multiple degrees of freedom by the at least three multi-degree-of-freedom actuators.
7. The stage device according to claim 6 , wherein a number of the at least three multi-degree-of-freedom actuators is three, and wherein the at least three multi-degree-of-freedom actuators are placed horizontally in an XY plane and differ in angle from each other by 120 degrees.
8. The stage device according to claim 6 , wherein a number of the at least three multi-degree-of-freedom actuators is four, and wherein two of the at least three multi-degree-of-freedom actuators are arranged horizontally along the X direction, and other two of the at least three multi-degree-of-freedom actuators are arranged horizontally along a Y direction.
9. The stage device according to claim 6 , further comprising a linear motor capable of moving significantly in one direction.