A damper assembly includes an outer cylinder, an inner cylinder positioned at least partially within the outer cylinder, a plunger positioned at least partially within the inner cylinder and coupled to a rod, an aperture extending through the rod, an annular piston coupled to the inner cylinder, and a valve assembly. The rod is positioned at least partially within the inner cylinder and has an outer dimension that is smaller than an inner dimension of the inner cylinder. The plunger and an interior of the inner cylinder at least partially define a first chamber. The valve assembly is in fluid communication with the first chamber and a second chamber. The annular piston extends between the inner cylinder and the outer cylinder, and the annular piston, an exterior surface of the inner cylinder, and the outer cylinder at least partially define the second chamber.

A damper assembly includes an outer cylinder, an inner cylinder positioned at least partially within the outer cylinder, a plunger positioned at least partially within the inner cylinder and coupled to a rod, an aperture extending through the rod, an annular piston coupled to the inner cylinder, and a valve assembly. The rod is positioned at least partially within the inner cylinder and has an outer dimension that is smaller than an inner dimension of the inner cylinder. The plunger and an interior of the inner cylinder at least partially define a first chamber. The valve assembly is in fluid communication with the first chamber and a second chamber. The annular piston extends between the inner cylinder and the outer cylinder, and the annular piston, an exterior surface of the inner cylinder, and the outer cylinder at least partially define the second chamber.

A vehicle suspension is disclosed having a hydraulic actuator, a cylinder, a piston mounted inside the cylinder dividing the cylinder into a compression chamber and an extension chamber, and a supply hydraulic circuit connected to the actuator to supply the compression chamber and the extension chamber with working fluid. The supply hydraulic circuit includes a high-pressure line connected to a delivery port of a hydraulic pump, a low-pressure line connected to a suction port of the pump, a spool valve connected to the compression and extension chambers of the actuator and to the high-pressure line and to the low-pressure line to put the chambers of the actuator in communication with the lines of the supply hydraulic circuit, and a first pressure accumulator connected to the high-pressure line . The spool valve connects the compression chamber and/or the extension chamber of the actuator with the high-pressure line.

A vehicle suspension is disclosed having a hydraulic actuator, a cylinder, a piston mounted inside the cylinder dividing the cylinder into a compression chamber and an extension chamber, and a supply hydraulic circuit connected to the actuator to supply the compression chamber and the extension chamber with working fluid. The supply hydraulic circuit includes a high-pressure line connected to a delivery port of a hydraulic pump, a low-pressure line connected to a suction port of the pump, a spool valve connected to the compression and extension chambers of the actuator and to the high-pressure line and to the low-pressure line to put the chambers of the actuator in communication with the lines of the supply hydraulic circuit, and a first pressure accumulator connected to the high-pressure line . The spool valve connects the compression chamber and/or the extension chamber of the actuator with the high-pressure line.

Methods and systems for hydraulic vehicle suspension are provided. A hydraulic suspension system, in one example, includes a first manifold including a piston-side interface and a rod-side interface fluidically coupled to a piston chamber and a rod chamber, respectively, for each of a first hydraulic cylinder and a second hydraulic cylinder. In the system, the first manifold includes a first electrically activated valve fluidically coupled to the piston-side interfaces, a first damping device, and a second damping device, the first electrically activated valve is configured to lock and unlock vertical motion of the first and second hydraulic cylinders and, while vertical motion of the first and second hydraulic cylinders is locked, the first electrically activated valve permits fluidic communication between the first and second hydraulic cylinders to permit free roll motion in the hydraulic suspension system.

A suspension system including four dampers is disclosed where each damper includes a compression chamber and a rebound chamber. A first hydraulic circuit includes a front hydraulic line, a rear hydraulic line, and a first longitudinal hydraulic line that extends between and fluidly connects the front and rear hydraulic lines of the first hydraulic circuit. A second hydraulic circuit includes a front hydraulic line, a rear hydraulic line, and a second longitudinal hydraulic line that extends between and fluidly connects the front and rear hydraulic lines of the second hydraulic circuit. First and second longitudinal comfort valves are positioned in the first and second longitudinal hydraulic lines, respectively, between the front and rear hydraulic lines. Both of the first and second longitudinal comfort valves are electromechanical valves and can be actuated to couple and decouple front axle roll control from rear axle roll control.

A milling machine may have a frame, a milling drum attached to the frame, and ground engaging tracks that support the frame and propel the milling machine in a forward or rearward direction. The milling machine may have height adjustable actuators connecting the frame to the tracks. Each actuator may have a cylinder attached to the frame, a piston slidably disposed within the cylinder, and a rod connected at a first end to the piston and connected to a track at a second end. The milling machine may have a tank storing hydraulic fluid and a fluid conduit connecting the tank to the cylinder. The milling machine may have a control valve selectively controlling a flow rate of the hydraulic fluid in the fluid conduit. The milling machine may also have a controller that determines a height of the frame relative to the ground surface based on the flow rate.

A system for filling a tank of a suspension system with hydraulic fluid includes: a module configured to turn on an external pump and pump hydraulic fluid into the suspension system, where the external pump is separate from the suspension system and is configured to pump hydraulic fluid into the suspension system via a port fluidly connected to a hydraulic line of the suspension system; and a fill module configured to, after operating the external pump, operate a pump of the suspension system and pump hydraulic fluid from the hydraulic line into the tank of the suspension system thereby filling the tank.

A vehicle includes a suspension system having a first damper, a second damper, and a controller. The dampers include housings and pistons sealingly interfaced with an inner diameter of the housing, dividing the damper into a first and second chamber. The suspension system includes proportional variable relief valves which control pressure of fluid entering or exiting one of the first and second chamber of one of the first and second damper. The controller controls the valves to control extension or compression of the first damper and extension or compression of the second damper based on a degree of roll of the vehicle during a turn of the vehicle or a degree of pitch of the vehicle during acceleration or deceleration of the vehicle. The first and second damper control a roll and pitch of the vehicle. The valves control a damping rate of one of the first and second damper.

A suspension system for supporting a body relative to at least four points, including: a respective front left, front right, back left and back right support arrangement between the respective point and the body, each respective support arrangement including a respective resilience arrangement and a respective control ram, each respective control ram including a respective compression chamber forming at least part of a respective compression control volume; a control arrangement including a first and a second diagonal reversible pump for displacing fluid between diagonally opposite compression control volumes. Each respective resilience arrangement can include a respective damping arrangement to restrict and/or selectively prevent compression and/or expansion of at least a portion of the respective resilience arrangement. Each respective control ram can further include a respective rebound chamber, the front control rams being cross connected and the back control rams being cross connected.