Abstract: A preferably totally oil-free spiral compressor (1) with a high suction volume flows and a high compression ratio, is useful in particular to generate compressed air for rail vehicles. The compressor includes two spirals arranged on one side only, and includes measures to exactly guide both spirals relative to each other. For that purpose, a compression crown (15) is connected to and axially spaced from a first one of the spirals (7), and the second spiral (9) is positively guidedly driven within the compression crown (15) by a positive guidance arrangement. The positive guidance arrangement includes support rollers (17) that extend axially from the second spiral toward the compression crown and that are engaged and constrained to roll in bores (19) let into the compression crown (15) and shaped as guiding rings.

Abstract: An air-drying system, in particular for the pneumatic braking systems of rail vehicles, including at least two air-drying chambers (1L, 1R) interconnected with one another via first and second regeneration lines (2 and 2'). In a reversibly switchable manner one of the chambers is used for air drying and the respective other chamber is used for regeneration of the air-drying agent (adsorbate) contained in the chambers. The second regeneration line (2') can be switched on and off as necessary to provide two different flow rates of regeneration air.