Land vehicle provided with a frame; four wheels; and four compensation systems each associated with a respective wheel. The vehicle is also provided with a control unit, in particular a hydraulic control unit, which has compensation systems and connects each wheel to the other wheels. The vehicle has a plurality of hydraulic filters, which are each arranged between a wheel and the respective compensation system; the hydraulic filters are low-pass filters designed to reduce (in particular stop), in case of undesired frequencies, the flow of a transmission fluid and, hence, the association between the wheel and the respective compensation system.

Land vehicle provided with a frame; four wheels; and four compensation systems each associated with a respective wheel. The vehicle is also provided with a control unit, in particular a hydraulic control unit, which has compensation systems and connects each wheel to the other wheels. The vehicle has a plurality of hydraulic filters, which are each arranged between a wheel and the respective compensation system; the hydraulic filters are low-pass filters designed to reduce (in particular stop), in case of undesired frequencies, the flow of a transmission fluid and, hence, the association between the wheel and the respective compensation system.

A semi-trailer for transporting a load to be moved has a wheeled front module having a right-hand front row and a left-hand front row of front bogies each provided with a respective hydraulic suspension driven by its own hydraulic cylinder; a wheeled rear module comprising a right-hand rear row and a left-hand rear row of rear bogies each provided with a respective hydraulic suspension driven by its own hydraulic cylinder; a coupling unit of the wheeled front module for the coupling to a tractor and comprising a pair of hydraulic jacks for transferring a part of the load to be moved to the tractor; a first hydraulic unit interposed between the hydraulic cylinders of the front and rear rows of bogies and configured in such a way that the sum of the instantaneous load-supporting pressures acting on the hydraulic cylinders of the right front row and of the cylinders of the left-hand rear row is equal to the sum of the instantaneous pressures controlling the cylinders of the left-hand front row and of the cylinders of the right rear row; and a second hydraulic unit configured to control the hydraulic jacks based on the sum of the instantaneous load-supporting pressures acting on the hydraulic cylinders of said right front row and of said left-hand front row.

A semi-trailer for transporting a load to be moved has a wheeled front module having a right-hand front row and a left-hand front row of front bogies each provided with a respective hydraulic suspension driven by its own hydraulic cylinder; a wheeled rear module comprising a right-hand rear row and a left-hand rear row of rear bogies each provided with a respective hydraulic suspension driven by its own hydraulic cylinder; a coupling unit of the wheeled front module for the coupling to a tractor and comprising a pair of hydraulic jacks for transferring a part of the load to be moved to the tractor; a first hydraulic unit interposed between the hydraulic cylinders of the front and rear rows of bogies and configured in such a way that the sum of the instantaneous load-supporting pressures acting on the hydraulic cylinders of the right front row and of the cylinders of the left-hand rear row is equal to the sum of the instantaneous pressures controlling the cylinders of the left-hand front row and of the cylinders of the right rear row; and a second hydraulic unit configured to control the hydraulic jacks based on the sum of the instantaneous load-supporting pressures acting on the hydraulic cylinders of said right front row and of said left-hand front row.

Disclosed herein are hydraulic actuators and methods for the operation of actuators having variable relative pressure ratios. Further disclosed are methods for designing and/or operating a hydraulic actuator such that the actuator exhibits a variable relative pressure ratio. In certain embodiments, the relative pressure ratio of the hydraulic actuator may be dependent on one or more characteristics (such as, for example, frequency or rate of change) of an oscillating input to the hydraulic actuator.

A control device for an oscillating axle suspension, in particular a front axle suspension, includes at least of one hydraulic accumulator device (10), a suspension device (12) and a proportional valve (14) having a valve piston (26). The proportional valve (14) is connected to the accumulator and suspension devices (10, 12) via fluid ports (16, 18, 20, 22). The valve piston (26) is actuatable by an electric motor (28), is longitudinally guided in a valve housing (24) of the proportional valve (14) and controls the fluid ports (16, 18, 20, 22) such that, in at least one functional position of the valve piston (26), the axle oscillation is provided while the suspension is blocked and, in at least one further second functional position of the valve piston (26), the suspension is provided while the axle oscillation is blocked.

A control device for an oscillating axle suspension, in particular a front axle suspension, includes at least of one hydraulic accumulator device (10), a suspension device (12) and a proportional valve (14) having a valve piston (26). The proportional valve (14) is connected to the accumulator and suspension devices (10, 12) via fluid ports (16, 18, 20, 22). The valve piston (26) is actuatable by an electric motor (28), is longitudinally guided in a valve housing (24) of the proportional valve (14) and controls the fluid ports (16, 18, 20, 22) such that, in at least one functional position of the valve piston (26), the axle oscillation is provided while the suspension is blocked and, in at least one further second functional position of the valve piston (26), the suspension is provided while the axle oscillation is blocked.

A damper assembly includes an outer cylinder, an inner cylinder positioned at least partially within the outer cylinder, a cap coupled to the inner cylinder, and a plunger positioned radially inward from the inner cylinder and coupled to a rod. The plunger, the cap, and an interior of the inner cylinder at least partially define a first chamber. The suspension system further includes a passage extending through the rod and fluidly coupled with the first chamber, a piston coupled to the inner cylinder and extending radially outward toward the outer cylinder, a first port in fluid communication with the plunger through the passage, and a second port in fluid communication with the piston. The piston, an exterior surface of the inner cylinder, and the outer cylinder at least partially define a second chamber.

A damper assembly includes an outer cylinder, an inner cylinder positioned at least partially within the outer cylinder, a cap coupled to the inner cylinder, and a plunger positioned radially inward from the inner cylinder and coupled to a rod. The plunger, the cap, and an interior of the inner cylinder at least partially define a first chamber. The suspension system further includes a passage extending through the rod and fluidly coupled with the first chamber, a piston coupled to the inner cylinder and extending radially outward toward the outer cylinder, a first port in fluid communication with the plunger through the passage, and a second port in fluid communication with the piston. The piston, an exterior surface of the inner cylinder, and the outer cylinder at least partially define a second chamber.

Disclosed herein are hydraulic actuators and methods for the operation of actuators having variable relative pressure ratios. Further disclosed are methods for designing and/or operating a hydraulic actuator such that the actuator exhibits a variable relative pressure ratio. In certain embodiments, the relative pressure ratio of the hydraulic actuator may be dependent on one or more characteristics (such as, for example, frequency or rate of change) of an oscillating input to the hydraulic actuator.