Pneumatic piston-and-cylinder unit for actuating welding electrode holders

摘要

The pneumatic piston-and-cylinder unit consists of a cylinder body (1) and an axially movable piston (2) with a piston rod (3). The piston bounds at least one working or cylinder chamber (4), while the piston rod is movable in a linear bearing (11) in a cylinder body. The unit is characterised by the following facts: (a) the cylinder body is provided with a gliding layer(6) which consists of a ceramic or a similar material, is produced by a hard-coating process; (b) the cylinder rod is provided with a similar layer (10) over at least its part interacting with the linear bearing; (c) the piston has at least one glide ring (8); (d) similarly, the linear bearing has ceramic surface. The piston-and cylinder unit is intended for actuating spot-welding electrode holders.