摘要 |
A planar motor (32) for positioning a stage (44) along a first axis, and along a second axis that is perpendicular to the first axis includes a conductor array (52) and a magnet array (34). The conductor array (52) includes at least one conductor (256). The magnet array (34) is positioned near the conductor array (52) and is spaced apart from the conductor array (52) along a third axis that is perpendicular to the first axis and the second axis. The magnet array (34) includes a first magnet unit (264) having a first diagonal magnet (D1) with a diagonal magnetization direction (268) that is diagonal to the first axis, the second axis and the third axis. This leads to strong magnetic fields above the magnet array (34) and strong force generation capability. Further, the planar motor (32) provided herein has less stray magnetic fields that extend beyond the magnet array (34) than a comparable prior art planar motor. Moreover, the first magnet unit (264) can include a second diagonal magnet (D2), a third diagonal magnet (D3), and a fourth diagonal magnet (D4) that cooperate to provide a first combined magnetic flux (276) that is somewhat aligned along the third axis in a first flux direction. In this embodiment, each diagonal magnet (D1) (D2) (D3) (D4) has the diagonal magnetization direction (268) that is diagonal to the first axis, the second axis and the third axis. Moreover, each diagonal magnet (D1) (D2) (D3) (D4) can be generally triangular wedge shaped and the diagonal magnets (D1) (D2) (D3) (D4) are arranged together into the shape of a parallelepiped.
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