A disclosed lift axle is suitable for a vehicle that has a first wheel for supporting the vehicle on a road surface. The lift axle system includes a lift mechanism that is coupled to the vehicle and is configured to reciprocate an axle between a stowed position and deployed position. The lift axle system further includes a second wheel coupled to the axle. The second wheel engages the road surface when the lift mechanism is in the deployed position, and the second wheel is disengaged from the road surface when the lift mechanism is in the stowed position. The second wheel has a lower rolling resistance than the first wheel.

A method of decreasing tire pressure includes opening a wheel valve (22) to allow pressurized air from a tire (10) to be directed to a first valve assembly (14) and to atmosphere. A target pressure is selected for a fluid control conduit (28). The fluid conduit (28) is in fluid communication with the first valve assembly (14) and a second or control valve assembly (30). The pressure in the fluid conduit (28) is measured. If the measured pressure is greater than the target pressure, then the second valve assembly (30) is de-energized. If the measured pressure is less than the target pressure, then the second valve assembly (30) is energized. A valve (42) prone to leak under very low temperatures may be subjected to repeated cycles of pressure application and pressure release in order to form a fluid-tight seal.

A suspension system for controlling movement of a vehicle wheel may include a spring and damper assembly coupling the wheel to the vehicle chassis for movement of the wheel relative to the vehicle chassis. The spring and damper assembly may include a spring coupled to a damper member configured to extend and retract the wheel relative to the vehicle chassis. The suspension system may further include a damper actuator located remotely from the spring and damper assembly and configured to modify an amount of damping and/or wheel extension. The suspension system may also include a spring actuator integrated with the damper actuator and configured to control an amount of deflection of the spring and/or to alter a spring rate. The damper actuator may be provided at a location in the vehicle separated from the spring and damper assembly.

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.

An active suspension system for a vehicle having a wheel that is subject to an external force includes an actuator having an output structure that is connected to the wheel, an energy storage device having a compressible chamber, a valve assembly that is operable to control flow of a working fluid between the actuator and the energy storage device, and a controller that determines whether to permit or resist motion of the output structure in response to the external force. The controller permits motion of the output structure by allowing fluid to flow from the actuator to the energy storage device using the valve assembly, thereby compressing the compressible chamber. The controller resists motion of the output structure by allowing fluid to flow from the energy storage device to the actuator using the valve assembly, thereby expanding the compressible chamber.

An air suspension system includes a tank, a tank-side open/close valve, an air suspension-side open/close valve, a system portion, and the like. The system portion includes a compressor, an air drier, and a first passage and a second passage provided between the tank-side open/close valve and the air suspension-side open/close valve in parallel, a discharge valve, a tank-side control valve, an air suspension-side control valve, and the like. Due to this configuration, the air suspension system regenerates the air drier by opening the discharge valve to thus cause the air in the second passage to flow from an opposite side toward one side of the air drier when no power is supplied to the tank-side control valve and the air suspension-side control valve.

Techniques are described for compensating for movements of sensors on a vehicle. A method includes receiving two sets of sensor data from two sets of sensors, where a first set of sensors are located on a roof of a cab of the semi-trailer truck and a second set of sensor data are located on a hood of the semi-trailer truck. The method also receives from a height sensor a measured value indicative of a height of the rear of a rear portion of the cab of the semi-trailer truck relative to a chassis of the semi-trailer truck, determines two correction values, one for each of the two sets of sensor data, and compensates for the movement of the two sets of sensors by generating two sets of compensated sensor data. The two sets of compensated sensor data are generated by adjusting the two sets of sensor data based on the two correction values.

In a suspension system in which the oil chambers of two dampers are connected, the responsiveness of the dampers can be adjusted. A suspension system has a left damper, a right damper, and an intermediate unit. A case of the intermediate unit has an intermediate oil chamber connected to an oil chamber of the left damper and the oil chamber of the right damper and an intermediate gas chamber. The intermediate oil chamber and the intermediate gas chamber are partitioned by a diaphragm. The intermediate unit has a capacity adjustment mechanism including a movable portion of which the position can be changed. The capacity adjustment mechanism adjusts the capacity of the intermediate gas chamber by changing the position of the movable portion.

A disclosed lift axle is suitable for a vehicle that has a first wheel for supporting the vehicle on a road surface. The lift axle system includes a lift mechanism that is coupled to the vehicle and is configured to reciprocate an axle between a stowed position and deployed position. The lift axle system further includes a second wheel coupled to the axle. The second wheel engages the road surface when the lift mechanism is in the deployed position, and the second wheel is disengaged from the road surface when the lift mechanism is in the stowed position. The second wheel has a lower rolling resistance than the first wheel.

An air suspension for a vehicle includes a mounting bracket configured to couple to the vehicle. A pivot bracket includes a top and a bottom. The top is pivotably coupled to a frontward portion of the mounting bracket. An air shock absorber includes a first end and a second end. The first end is pivotably coupled to the bottom of the pivot bracket and the second end is pivotably coupled to a rearward portion of the mounting bracket. An axle arm includes a first portion and a second portion. The first portion of the axle arm is fixedly coupled to the frontward portion of the mounting bracket. A spindle is fixedly coupled to the second portion of the axle arm and is configured to be coupled to a hub assembly of a wheel.