The present invention relates to a transfer apparatus having a primary part, at least one first or one second secondary part, which are each magnetically coupled to the primary part for drive purposes, and a regulation device for regulation of a drive of the secondary parts. The present invention also relates to a corresponding method for magnetic driving of at least one first and one second secondary part with a primary part.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
A transfer apparatus is used, for example, for transportation and precise positioning of workpiece carriers with workpieces arranged on them. A transfer apparatus such as this can also be used as part of and/or along a conveyor path. One or more processing stations and one or more positioning modules, suitably with a positioning drive by means of a linear motor, can be arranged along the conveyor path. Furthermore, a transfer apparatus may, however, also be used, for example, for transportation of goods or people, preferably in decentralized arrangements, over long distances and in network systems (transport systems of widely different types).
In conventional transfer apparatuses, for example having 3-phase motors, each phase group is hard-wired to a rigidly associated regulator. Motors arranged in series are regulated via an appropriately associated regulator in a respectively defined drive and transmitter zone. However, systems such as these have the disadvantage that every secondary part and every workpiece carrier must be associated with one fixed zone of the primary part, in order that it can be moved deliberately along the primary part. In some circumstances, this means that relatively long distances must be maintained between the individual secondary parts and workpiece carriers. In addition, all the secondary parts are moved along the primary part in accordance with a fixed predetermined regulation rule. In general, this allows only relatively poor positioning accuracy to be achieved.
It would therefore be desirable and advantageous to provide an improved transfer apparatus to obviate prior art shortcomings and to attain an increase in throughput while yet improving positioning accuracy.