US Patent 10994953 Tray conveyor driven by brushless DC motor

A conveyor for conveying articles supported on independently powered and controllable trays. Each tray comprises a blade suspended from an article-supporting platform. A series of drive coils is embedded in the blade. A battery and a controller embedded in the tray drive the drive coils. The blade rides in a slot between two conveyor rails that support the tray platform. The slot is bounded by an array of permanent magnets along each rail. The drive coils produce an electromagnetic field that interacts with the permanent-magnet field in the slot to form a brushless dc motor that propels the tray along the rails.