A load based tire pressure regulation system for trucks or trailers employing an air spring maintained at a variable pressure P.sub.AS depending upon the load on the truck or trailer, includes an air pilot pressure regulator receiving air at pressure P.sub.AS and air at the pressure of at least one tire of a truck or trailer, and configured to feed air to and bleed air from the at least one tire of the truck or trailer as a function of the load on the truck or trailer. The pressure regulator is configured to feed air to and bleed air from the at least one tire of the truck or trailer based upon the pressure of the air spring P.sub.AS as a function of the load on the air spring (F.sub.AS), and further upon the recommended pressure P.sub.T of the at least one tire as a function of the load on the tire (F.sub.T).

A suspension includes a housing, a radius arm, a radius arm bush, and a shock absorber. Inclination angles θ1 and θ2 satisfy ΔF.Math.tan θ2>M.Math.tan θ1, in which: θ1 is an inclination angle at which a straight line coupling the center of the radius arm bush to the center of a rear wheel is inclined to a horizontal line, to lower toward the rear wheel, viewed from a side of the vehicle in a steady state; θ2 is an inclination angle at which an axis of expansion and shrink of the shock absorber is inclined to a vertical direction, to allow the shock absorber's upper end to more forward from the shock absorber's lower end; M is an unsprung mass of the suspension; and ΔF is an amount of increase in a vertical load on the rear wheel from the steady state during a shrinkwise stroke of the shock absorber.

A work vehicle including: a first link having one end portion supported by a vehicle body so as to be pivotable; a second link having one end portion pivotally coupled to the other end portion of the first link so as to be pivotable, and another end portion that supports a travel wheel; a first hydraulic cylinder capable of changing a swing posture of the first link; and a second hydraulic cylinder capable of changing a swing posture of the second link relative to the first link. The action of the first hydraulic cylinder is controlled such that a swing position of the first link is located at a target position, based on the result of detection performed by a position detection sensor, and the action of the second hydraulic cylinder is controlled such that thrust has a target value, based on the results of detection performed by pressure sensors.

A vehicle weight measurement device includes a diaphragm which covers an opening area of a groove portion of a mounting part to form an oil chamber of a predetermined space together with the groove portion; a pressure sensor which detects a change in pressure of measurement fluid in the oil chamber; a first piston which presses the diaphragm; a second piston which presses the first piston; and a bearing unit interposed between the second piston and a spring bush which receives one end of a spring of a suspension device and is relatively rotatable. The bearing unit includes a thrust needle bearing which swingably supports a load in a longitudinal direction of the suspension device, and a slide bush which does not receive a load in the longitudinal direction and receives a load in a radial direction while causing constant damping to swinging.

A vehicle suspension comprises a hub carrier on which a wheel hub is suitable for being mounted, a suspension arm having an outer end connected to the hub carrier by a ball joint and an inner end suitable for being attached to a suspended structure of the vehicle, and a shock absorber. At least one load responsive device is arranged on the suspension arm, the load responsive device comprising a sensor able to generate an output signal in response to a load applied to the suspension arm, wherein a control unit is configured to receive the output signal generated by the sensor and to adjust the stiffness of the shock absorber through a valve adapted to vary passage cross-sections of the fluid contained in the shock absorber.

At least one controller configured to control an actuator of an active suspension system. The at least one controller includes circuitry configured to determine an actuator state, and apply the actuator state and a commanded state to an inverse model of the actuator to produce an actuator command. The circuitry is configured to produce the actuator command by a process that includes performing low pass filtering and phase compensation to correct a phase introduced by the low pass filtering.

A vehicle weight measurement device includes a diaphragm which covers an opening area of a groove portion of a mounting part to form an oil chamber of a predetermined space together with the groove portion; a pressure sensor which detects a change in pressure of measurement fluid in the oil chamber; a first piston which presses the diaphragm; a second piston which presses the first piston; and a bearing unit interposed between the second piston and a spring bush which receives one end of a spring of a suspension device and is relatively rotatable. The bearing unit includes a thrust needle bearing which swingably supports a load in a longitudinal direction of the suspension device, and a slide bush which does not receive a load in the longitudinal direction and receives a load in a radial direction while causing constant damping to swinging.

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.

A machine includes a chassis having a first end and an opposing second end, an axle pivotally coupled to the first end of the chassis, a first actuator coupled to the first end of the chassis, and a second actuator coupled to the first end of the chassis. The chassis defines a longitudinal center axis. The axle is configured to rotate about the longitudinal center axis. The first actuator is positioned on a first lateral side of the longitudinal center axis. The first actuator is extendable to selectively engage a first contact point on the axle. The second actuator is positioned on an opposing second lateral side of the longitudinal center axis. The second actuator is extendable to selectively engage a second contact point on the axle.

A vehicle suspension comprises a hub carrier on which a wheel hub is suitable for being mounted, a suspension arm having an outer end connected to the hub carrier by a ball joint and an inner end suitable for being attached to a suspended structure of the vehicle, and a shock absorber. At least one load responsive device is arranged on the suspension arm, the load responsive device comprising a sensor able to generate an output signal in response to a load applied to the suspension arm, wherein a control unit is configured to receive the output signal generated by the sensor and to adjust the stiffness of the shock absorber through a valve adapted to vary passage cross-sections of the fluid contained in the shock absorber.