A feed unit for drilling and/or tapping comprising a housing, a quill in the housing movable between retracted and extended positions, the quill rotationally supporting a spindle for carrying a rotary tool, a screw for moving the quill between said positions, a ball spline shaft in the housing coaxial with the spindle, a ball spline nut having recirculating steel balls rolling in raceways on the ball spline shaft, the spindle radially supporting the ball spline shaft within the quill with zero clearance through the ball spline nut, rotation of the ball spline shaft being imparted to the spindle through the ball spline nut.

A rotary union including a housing, a piston, and a shaft is provided. The piston has a first fluid passage therethrough and is configured to slide axially between a first position and a second position. The shaft has a second fluid passage therethrough and is configured to rotate. A first port is arranged in the housing and is in fluid communication with a cavity formed between the housing and the piston. The first port is configured to deliver a pressurized fluid into the cavity to actuate the piston from the first position to the second position. A chamber is formed in the housing and surrounds an interface between the first and second fluid passages. A second port arranged in the housing is in fluid communication with the chamber. The second port is configured to apply a vacuum to the chamber to evacuate fluid leaked into the chamber from the interface.

The peeling machine, comprising: a rotating head installed rotating about an axis of rotation and provided with a central cavity in which, during use, there is disposed an elongated product to be worked; the rotating head is provided with a plurality of tools and with at least one adjustment unit configured to move the tools away from or toward the elongated product; a first motor configured to make the rotating head rotate about the axis of rotation; and a transmission unit configured to transmit motion from a second motor to the adjustment unit in order to simultaneously adjust the radial position of the tools; the transmission unit comprises a differential device kinematically connected between the second motor and the adjustment unit so that an adjustment of the position of the tools with respect to the elongated product corresponds to the drive of the second motor.

A rotary feedthrough for the feedthrough of a powder-gas mixture from a stationary machine part into a rotating machine part, with a seal in the form of two flat circular-ring-shaped sliding seal surfaces arranged one on the other in a sliding manner, which sliding seal surfaces are arranged concentric to the axis of rotation of the rotating machine part and which can be moved apart from each other in the axial direction, so that they form a gap, wherein the seal is embedded in a purge chamber having at least one gas inlet and at least one gas outlet.