US 5,641,054 AGranted

Magnetic levitation conveyor apparatus

AssigneeEbara Corporation

InventorsSatoshi Mori, Masao Matsumura, Yoichi Kanemitsu, Takeshi Yoshioka, Masaaki Kajiyama, Fumio Kondo, Yuji Shirao, Masato Eguchi, Hiroyuki Shinozaki, Yukio Ikeda, Masayoshi Hirose, Masaru Nakaniwa, Norio Kimura, Katsuaki Usui, Katsuyuki Aoki

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Abstract

A magnetic levitation conveyor apparatus has levitation electromagnets, linear motors, and displacement sensors which are disposed outside of a tunnel, and a carriage of simple structure which is movable in the tunnel. The carriage is of canned structure for preventing gases from being generated. The carriage of canned structure allows the tunnel to have a reduced cross-sectional area and to be filled with a highly purified atmosphere such as of a high vacuum. The tunnel has substantially orthogonal branches at a branched point. In the branched point, the carriage can move, while being lifted out of contact with the tunnel partition, with a directional change from a main conveyor passage into a branched conveyor passage. The magnetic levitation conveyor apparatus is highly practical as it can control the carriage to be lifted and moved as described above.

Claims16

Dependent claims

A magnetic levitation conveyor apparatus, comprising:

a tunnel defined by a partition;
a carriage movable in a levitated state through said tunnel for conveying a workpiece;
levitation electromagnets having at least two rows of magnetic poles disposed on an upper portion of said partition of said tunnel for lifting the carriage out of contact with the partition;
electromagnets serving as linear motors and having at least one row of magnetic poles disposed on a lower portion of said partition of said tunnel for moving said carriage out of contact with the partition;
at least two rows of displacement sensors disposed on said partition for detecting a levitated portion of said carriage;
and
control circuits for controlling exciting currents supplied to said levitation electromagnets based on output signals from said displacement sensors,
said carriage having, on an upper surface thereof, two parallel magnetic elements corresponding to said two rows of magnetic poles of the levitation electromagnets, and also having, on a lower surface thereof, an electrically conductive member corresponding to the magnetic poles of the electromagnets serving as the linear motors.

5 more elements

Dependencies are inferred from the claim text.