Centrifuge

A centrifuge ( 10 ) is provided with a cantilevered shaft ( 18 ) upon which the main drive rotor ( 26 ) is located. A bobbin ( 62 ) is attached to the planetary gear shaft ( 44 ), which is driven in planetary motion by the rotation of the rotor ( 26 ) and its toothed engagement with the shaft ( 18 ) of the cantilevered rotor. A flying lead section ( 72 ) extends from the bobbin ( 62 ) through an aperture in the cantilevered rotor ( 26 ). The arrangement provides a centrifuge structure which can handle higher rotational speeds while maintaining resolution. The flying lead section ( 72 ) provides a simple path for the inlet and outlet leads ( 84,86 ) which reduces dead volume and increases reliability. The bobbin ( 62 ) supports at least one coil ( 68 ). Rotor component ( 44 ) includes at least one bearing ( 50, 52 ). Attachment means ( 66 ) are provided removably to attach the bobbin ( 62 ) to the rotor component ( 44 ), the attachment means ( 66 ) enabling removal of the bobbin ( 62 ) from the rotor without removal of the or any bearing ( 50, 52 ) of the rotor component ( 44 ). In the preferred embodiment, the attachment means ( 66 ) removably attaches the bobbin ( 62 ) to an end of the rotor component ( 44 ). A gear assembly ( 40 ) for the centrifuge ( 10 ) is enclosed in a chamber ( 56 ) of a rotor ( 26 ), which chamber ( 56 ) can be provided with lubricant. A chromatography coil assembly is formed from a plurality of rigid substrates ( 10, 12 ) which are disc-shaped in plan view. Produced within each substrate ( 10, 12 ) is a channel ( 14, 16 ) which is closed by the lower surface of the substrate lying thereon, as shown in relation to channel ( 14 ). A coupling conduit couples the two channels ( 14, 16 ) together to form a unitary coil.