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 vehicle-height control system includes: a fluid supply and discharge device including a compressor device and a tank storing fluid pressurized by the compressor device; a vehicle-height control actuator corresponding to a wheel and connected to the fluid supply and discharge device; a vehicle height controller that controls a vehicle height for the wheel by controlling the fluid supply and discharge device to control supply and discharge of fluid to and from the vehicle-height control actuator; a tank pressure controller that controls a tank pressure; and a fluid supply controller that supplies the fluid to a low pressure portion by controlling the fluid supply and discharge device at start and/or termination of at least one of control executed by the vehicle height controller and control executed by the tank pressure controller. The low pressure portion is at least a portion of the fluid supply and discharge device.

A lift axle suspension for a tandem trailer has first and second suspension air bags for first and second axles. There is a lift air bag that, when pressurized, applies a lifting force to lift the second axle relative to the first axle. A first pneumatic circuit supplies compressed air to the first suspension air bag and a diverter valve and is controlled by a height selector valve that is opened and closed based on the ride height of the trailer. The diverter valve selectively supplies compressed air to the second suspension air bag and a pressure regulator that limits air pressure to a predetermined pressure. A second pneumatic supplies compressed air to the lift air bag and is controlled by a pilot valve.

A vehicle suspension includes at least one anchor bar, at least one axle lift spring, an auxiliary drop-type axle which may be selectively lifted or lowered and a single, integrated support attaching the at least one axle lift spring and the at least one anchor bar to the auxiliary drop-type axle, wherein the single, integrated support provides the only attachment of the at least one axle lift spring and the at least one anchor bar to the auxiliary drop-type axle, and wherein the support includes an open area configured to allow the passage of a cardan.

A suspension and steering mechanism for a vehicle including at least one suspension arm, a steering arm, and a steering actuator. The suspension arm includes a wheel mounting end and a base end rotatably coupled with a reference frame via a base axis. The steering arm is coupled with the suspension arm at a rotation point of the steering arm. An actuated end of the steering arm extends toward a first direction from the rotation point. The steering actuator includes an actuating end and a fixed end, and is rotatably coupled at the fixed end with the suspension arm and rotatably coupled at the actuating end with the actuated end of the steering arm. A horizontal location of the fixed end is within at least one of a horizontal cross-section of the suspension arm and a triangle defined by the rotation point and the largest width of the base axis.

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 booster for a trailer system is provided comprising a control system in communication with a sensor(s) for determining the direction and speed of the booster when in motion. The control system comprises instructions corresponding to one or more booster operations such as: detection of a reverse state, retraction of a suspension system when the reverse state is detected; engagement of a steer axle lock when the reverse state is detected; detection of a forward state; extension of the suspension system when the forward state is detected; disengagement of the steer axle lock when the forward state is detected; detection of a high-speed forward state; engagement of the steer axle lock when the high-speed forward state is detected; detection of a low-speed forward state; and disengagement of the steer axle lock when the low-speed forward state is detected.

An anti-roll bar for a vehicle. The anti-roll bar includes a first bar portion for connection to a left-side wheel suspension of the vehicle and a second bar portion for connection to a right-side wheel suspension of the vehicle, and an actuator unit connecting the first bar portion and the second bar portion to each other for transferring torque between the first bar portion and the second bar portion. The actuator unit has a first selectable mode providing a first predetermined torque ratio between the first bar portion and the second bar portion, and a second selectable mode providing a second predetermined torque ratio between the first bar portion and the second bar portion. The first torque ratio and the second torque ratio are different from each other.

A pneumatic automotive height adjuster assembly provides at least one bag removably connected to a vehicle having a frame. The at least one bag is configured to adjust a height of the frame. An air supply line has a supply end and a discharge end. The discharge end is in fluid communication with each of the at least one bag. The air supply is configured to provide air to inflate the at least one bag. A switch is in fluid communication with the supply end of the air supply line. The switch has a first discharge, a second discharge, and a switch input. A leveling valve is in fluid communication with the first discharge. The air supply line is in fluid communication with the second discharge. An air supply is in fluid communication with the leveling valve and the switch input.

A suspension system for liftable steerable axles has at least one steering knuckle; at least one pistonless bellows air spring actuator (ie., damper air spring); and a steering axle structure that has, at each end, a kingpin housing boss, a kingpin fixed into the kingpin boss, and a pair of steering knuckles that rotate around the kingpin and are supported by the kingpin housing; wherein the steering knuckles are connected at the bottom of each other side to side by a tie rod assembly that respond to each others rotational inputs; and further having the damper air spring being connected to the steering knuckle so that, given a supplied pneumatic air force, the damper air spring stabilizes and dampens the steering road inputs when in motion.