A vehicle height adjustment system includes: a cylinder housing part having an inner space configured to receive working fluid; a piston part positioned in the cylinder housing part, the piston part configured to move linearly in response to the working fluid transferred to the cylinder housing; a damper rod part positioned in the piston part; a protrusion part protruding outward from the damper rod part; and a guide part formed in the piston part facing the protrusion part, wherein the protrusion part is inserted into the guide part.

The present disclosure relates to a hydraulic vehicle height adjustment device including a storage tank part configured to store a fluid, a housing part connected to the storage tank part and configured to define a flow path portion through which the fluid moves, a gear pump part inserted into the housing part and having gears configured to press the fluid, an electric motor part mounted on the housing part and configured to operate the gear pump part when electric power is applied, an adjustment part connected to the housing part and configured to change a height of a vehicle body by using hydraulic pressure, and a pulsation reducing part inserted into the housing part, connected to the flow path portion, and configured to maintain a constant movement amount of the fluid.

An air suspension system includes air suspensions (1, 2) performing vehicle height adjustment in response to supply and discharge of air, a compressor (3) compressing air, a tank (4) storing compressed air, a first passage (6) connecting between the delivery side of the compressor and the tank, and a second passage (7) connecting between the delivery side of the compressor and the air suspensions. A first dryer (10) is provided in the middle of the first passage to dry air flowing through the first passage. A second dryer (11) is provided in the middle of the second passage to dry air flowing through the second passage. Thus, compressed air generated from ambient air sucked in by the compressor can be dried by the second dryer and supplied directly into the air chambers of the air suspensions.

A method for operating a pneumatic system having a compressed air supply system and an air spring system includes determining at least one deflection of at least one air spring of the pneumatic system. The air spring is configured to be connected to a gallery in a selectively gas-conveying manner via a valve. The method further includes determining at least one bellows volume of a spring bellows of the at least one air spring based on the at least one determined deflection, indicating a pneumatic surrogate model for the at least one bellows volume and/or for a pressure accumulator volume of a pressure accumulator of the pneumatic system based on a mass flow balance for a balance volume, and calculating, based on the pneumatic surrogate model, at least one pressure value of the at least one bellows volume, the pressure accumulator volume, and/or the balance volume.

A mechanically actuated level control valve device for a commercial vehicle with an air suspension system is a level control valve and comprises a drive element that can be mechanically coupled to a vehicle wheel or axle. A valve element and a counter valve element have a first relative position, wherein the port for the air suspension bellow is closed, a second relative position, wherein the port for the air suspension bellow is connected to the port for the aeration device, and a third relative position, wherein the port for the air suspension bellow is connected to the port for the deaeration device. The valve element is coupled to a rotatable driveshaft of the level control valve by a drive mechanism. An integrated actuator changes the relative position of the valve element and the drive element or the relative position of the counter valve element and a valve housing.

A levelling valve assembly for an air suspension system of a heavy vehicle is provided, including an air valve configured to allow air to either enter or escape from an air spring based on a position of a control arm of the air valve, and including a linkage rod assembly configured to translate movement between a sprung and unsprung mass of the vehicle into a rotation of the control arm to regulate a ride height of the vehicle. The linkage rod assembly further includes a spring and damper arrangement configured to dampen or block movement of the control arm not caused by a change in a mass loading of the vehicle.

The invention relates to an axle assembly and a heavy-duty vehicle having such an axle assembly, which comprises a pivot bearing having a substantially vertically extending steering axis of rotation, a bogie rotatably arranged about the steering axis of rotation, a rocker mounted on the bogie so as to be pivotable about a substantially horizontal pivot axis, a wheel carrier operatively connected to the rocker having at least one wheel rotatably mounted thereon about a wheel axis of rotation, the wheel axis of rotation extending substantially horizontally and, when driving straight ahead, substantially transversely to the direction of travel, and a pneumatically actuatable power device, which is arranged between the rocker and the bogie.

A vehicle height control system includes a fluid feeder and a vehicle height control unit. The vehicle height control unit includes a communication control unit. In a first communication state, a high-pressure source and a common passage are made to communicate with each other via the first passage and the second passage. In a second communication state, the first passage is shut off and the high-pressure source and the common passage are made to communicate with each other via the second passage. The communication control unit selects one from among the plurality of communication states based on at least one of a content of a start condition, a target vehicle height of a height increasing control and a number of wheels to be controlled in the height increasing control, when the start condition of the height increasing control is satisfied.

A pet mode door and suspension control system and method includes determining whether a door control action has occurred with respect to a door on the vehicle. When determined that the door control action has occurred, the system and method further includes determining whether a pet mode control action is needed. When determined that the pet mode control action is needed, a suspension control command is sent to suspension control system for raising and/or lowering at least one side of the vehicle and a door control command is sent to a power control unit for opening or closing the door in accord with the door control action.

A vehicle suspension connects a vehicle body to a plurality of wheels and allows relative motion between the vehicle body and the wheels. The suspension system includes a plurality of telescoping multi-stage hydraulic cylinder assemblies arranged to selectively lift the vehicle body relative to the wheels when extended and to lower the vehicle body relative to the wheels when contracted. A control valve is used to adjust a volume of hydraulic fluid in the hydraulic cylinder assemblies to change a height of the vehicle. External spring packs are in fluid connection with the hydraulic cylinder assemblies to maintain spring forces on the suspension system over a range of telescopic movement of the hydraulic cylinder assemblies. Fluid damping valves are provided for damping telescopic movement of the hydraulic cylinder assemblies by restricting fluid flow between the hydraulic cylinder assemblies and the spring packs.