A shock absorber includes: a pressure tube defining a working chamber; a piston assembly slidably disposed within the pressure tube, the piston assembly dividing the working chamber into a first and second chambers; a piston rod including a first end that is attached to the piston assembly and that includes a second end that is configured to be attached to one of a sprung mass and an unsprung mass of a vehicle; an electronic valve that is positioned within the piston rod, the electronic valve including a spool moveable between first and second positions, where: when the spool of the electronic valve is in the first position, the spool allows fluid flow between the first and second chambers through the electronic valve and the piston rod; and when the spool of the electronic valve is in the second position, the spool restricts fluid flow between the first and second chambers.

A pneumatic lift axle control system includes a plurality of valves configured to receive first fluid pressure from a first fluid supply and to receive second fluid pressure from a second fluid supply, and to selectively communicate the first fluid pressure or the second fluid pressure as a pilot signal to a lift axle actuator valve.

A valve for an air spring includes a housing member having a center axis and a channel. The housing member includes first and second elements connected by a materially engaging connection in a first region and in abutment with each other in a second region or which are provided directly beside each other. A sealing member may be disposed in the channel and can close the channel or reduce an effective opening cross section. The valve may comprise a channel element that at least partially guides or forms the channel. The channel element may be fixed in the housing member in a form-fit and/or force-fit manner, and the channel element may retain the sealing member in a third region or the channel element may be fixed in/on the first element in a form-fit and/or force-fit manner, and the channel element may retain the sealing member in a third region.

A method of maintaining a backpressure of a fluidic product is provided. The method includes pressurizing a first reservoir to a first predetermined pressure level using compressed air, delivering the fluidic product to the pressurized first reservoir until a current level of the fluidic product in the first reservoir reaches a first predetermined level, pressurizing a second reservoir to a second predetermined pressure level using the compressed air, delivering the fluidic product to the pressurized second reservoir until a current level of the fluidic product in the second reservoir reaches a second predetermined level, and controlling the backpressure of the fluidic product using the first reservoir and the second reservoir such that a discharge flow of the fluidic product is continuous.

A suspension system for a vehicle is shown. The suspension system may have first and second airbags stacked upon each other. By adjusting a height difference between the first and second airbags while maintaining the same collective height of the first and second airbags, the spring rate of the collective first and second airbags are changed while maintaining the same collective height of the first and second airbags.

A compressed-air supply system for operating a pneumatic installation. The compressed-air supply system includes an air supply, the air supply comprising an air compressor unit configured to supply compressed air to a compressed air supply. The compressed-air supply system further includes a compressed air port to the pneumatic installation, an air removal port configured to release air to the environment, and a pneumatic main line between the compressed air supply and the compressed air port, the pneumatic main line comprising an air dryer and a throttle. Furthermore, the compressed-air supply system includes an air removal line between the compressed air port and the air removal port and an exhaust valve connected in the air removal line. The exhaust valve includes a pressure control port connected to the compressed air supply and a pressure counter control port connected to the compressed air port.

An air suspension control system (ECAS, electronic controlled air suspension) (10) for a utility vehicle, such as a truck or the like, or for a passenger car, includes a main control unit (12) for operating the air suspension control system (10)and at least two auxiliary control units (14) connected to the main control unit (12) via a data link (16). The auxiliary control units (14) each have at least one output (18) for actuating at least one actuator (20) which can be connected to the output (18), in particular an adjustment drive (28) for a valve (30). Furthermore, at least one function for generating control signals at the output (18) can be stored in the auxiliary control units (14), and the main control unit (12) is adapted to call up and/or to parameterize at least the stored functions by transmitting commands via the data link (16).

A method for operating a pressure control system having a multistage compressor includes providing, by the multistage compressor, a pressure medium that has been compressed multiple times in order to fill a pressure medium reservoir or pressure medium chambers of the pressure control system. The providing the pressure medium involves providing, by a first compression stage, a precompressed pressure medium and additionally compressing, via a second compression stage, the precompressed pressure medium, and/or introducing an already compressed charge pressure medium into an intermediate volume between the first compression stage and the second compression stage of the multistage compressor and further compressing, by the second compression stage, the charge pressure medium. The charge pressure medium simultaneously passes, via a control line, to a control input of a shut-off valve that interacts with the first compression stage, such that a charge pressure of the charge pressure medium predefines a control pressure.

An air suspension system capable of raising both the vehicle front wheel side and the vehicle rear wheel side by using a single tank. The air suspension system (1) includes a front wheel-side air suspension (2) and a rear wheel-side air suspension (7) which are interposed between a vehicle body and associated axles to perform vehicle height adjustment in response to supply and discharge of air, a compressor (17) for compressing air, and a tank (27) for storing air compressed by the compressor. When the vehicle height is to be raised by the air suspensions, the front wheel-side air suspension is supplied with compressed air from the tank, and the rear wheel-side air suspension is supplied with compressed air from the tank after the compressed air has been pressurized by the compressor.

A method for operating a pressure control system having a multi-stage compressor includes providing a multiply compressed pressure medium by the multi-stage compressor for filling a pressure medium reservoir or pressure medium chambers of the pressure control system. Providing the multiply compressed pressure medium includes (i) providing, by a first compression stage, a pre-compressed pressure medium and additionally compressing, at least by a second compression stage, the pre-compressed pressure medium, and/or (ii) introducing an already-compressed charging pressure medium into an intermediate volume between the first compression stage and the second compression stage of the multi-stage compressor and further compressing the charging pressure medium at least by the second compression stage. The charging pressure medium simultaneously passes via a control line to a control input of a shut-off valve that interacts with the first compression stage, such that a charging pressure of the charging pressure medium predefines a control pressure.