A vehicle-height control system includes: a fluid supply and discharge device including a compressor configured to suck fluid, and a tank configured to supply the fluid; an actuator-side passage connected to the fluid supply and discharge device; a vehicle-height control actuator provided for a wheel and connected to the actuator-side passage via a vehicle-height control valve; and a vehicle height controller configured to control a vehicle height for the wheel by controlling the fluid supply and discharge device and the vehicle-height control valve to control supply and discharge of the fluid in the vehicle-height control actuator. The vehicle height controller includes a start controller configured to open the vehicle-height control valve after establishing communication between the actuator-side passage and at least one of the tank and the compressor in a state in which the vehicle-height control valve is closed at a start of control of the vehicle height.

A method for controlling an air suspension system of a vehicle includes: a) determining a bellows pressure-time characteristic curve for air admission to and release from the bellows of one air spring or the bellows of a plurality of air springs, the characteristic curve being normalized with the value of a supply pressure in a reservoir for compressed air, b) sensor measurement of a current pressure in the spring bellows of the air springs as well as the current supply pressure immediately before air admission thereto or air release therefrom, c) determining, from the normalized characteristic curve, the opening duration for the associated shutoff valve using the ratio of the measured bellows pressure to the measured supply pressure and the ratio of the provided target pressure to the measured supply pressure, d) opening the associated shutoff valve for the determined opening duration in order to set the provided target pressure.

An air management system for a vehicle. The air management system includes at least one air spring. A compressor is provided for filling the air spring. A central air line is fluidly connected to the air spring and the compressor. At least one spring air line extends between the central air line and the air spring. At least one suspension valve is disposed along the spring air line. At least one auxiliary air line extends between the spring air line and the central air line. At least one high flow exhaust valve is disposed along the auxiliary air line. At least one isolation check valve is disposed in series with the high flow exhaust along the spring air line. The isolation check valve allows air to pass through therethrough from the air spring to the central air line while preventing air from passing therethrough from the central air line to the air spring.

A vehicle height adjustment apparatus includes: vehicle height adjustment units respectively provided to correspond to wheels of a vehicle body, and adjusting a vehicle height in response to the supply and discharge of a working fluid; a pressure tank storing the working fluid; a compressor pressure-feeding the working fluid; a valve body block formed by opening and closing valves, and interposed between the pressure tank and the compressor, and the vehicle height adjustment units; and a control unit adjusting a vehicle height by controlling the valve body block, wherein the valve body block is connected to the pressure tank, and working fluid outlet and inlet of the compressor, and upon the completion of the pressure feed of the working fluid, the control unit controls such that the working fluid outlet and inlet are communicated with each other.

A method of calculation a vehicle load comprising a first vehicle load value based at least on air pressures in air springs and height data of suspension of a vehicle axle, determining a second vehicle load value based on a change of track width of the vehicle axle, and calculating the vehicle load based on the first vehicle load value and the second vehicle load value.

An air suspension system includes an air supply system block including one or more air spring valves, where the one or more air spring valves are disposed within the air supply system block, the air supply system block having a valve block housing. The system further includes the air supply system block pneumatically coupled with one or more air springs, and at least one reservoir coupled with the air supply system block, at least one motor and pump disposed within the air supply system block. The air suspension further includes fast down leveling valves disposed within the air supply system block.

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.

The invention relates to a retaining ring for securing a component. The retaining ring includes a ring segment having an outer circumference for fixing the retaining ring in the axial direction, a recess extending along a circumferential direction of the ring segment, and a closure element for closing off the recess. In embodiments, the ring segment forms a contact surface to fix the component in the axial direction, and the retaining ring has a locking device for locking the closure element in the recess. In embodiments, the locking device is concealed at least on one side of the retaining ring facing away from the contact surface.

A suspension control valve arrangement for a pneumatic suspension system of a commercial vehicle includes a supply port, a delivery port, an exhaust port, a service valve arrangement, and an operation control mechanism (5, 6) for switching the service valve arrangement into one of the following normal operation modes of a normal operation status: a blocking position for a blocking mode for blocking an air supply from the supply port to the delivery port, a supply position for a supply mode for supplying air from the supply port to the delivery port, or an exhaust position for a normal exhaust mode for connecting the delivery port to the exhaust port. A dump-control device (7, 11) in the housing (2) is configured for switching between the normal operation status and a quick-dump mode (IV), win which the delivery port is connected to the exhaust port by bypassing the service valve arrangement.

A suspension system is provided comprising at least one ride height valve, when engaged, that allows an air flow to engage a hydraulic control valve such that it initiates either extension or retraction of a hydraulic piston from a cylinder. Extension or retraction of the hydraulic piston causes a booster frame to be bias downwardly or upwardly, respectively. The ride height valve is engaged when a booster axle is at a predetermined distance from the frame.