A suspension device, in particular for axle suspensions in tractors, having at least one suspension cylinder, the piston rod unit (12) of which separates a piston side (18) from an annular side (14) in a cylinder housing (20), is characterized in that a pressure relief valve (26) is used to limit a maximum pressure at the annular side (14) of the relevant suspension cylinder.

A method for pivoting a travel unit on a machine frame of a road milling machine between an outer end position and an inner end position offset toward a center of the machine relative to the outer end position, the road milling machine having a travel mechanism with multiple travel units, of which at least one travel unit is height-adjustable via a lifting column, comprising the steps of positioning a support foot mounted on the machine frame in a ground contact position to support the machine frame, lifting the travel unit, pivoting the travel unit between the outer end position and the inner end position, lowering the travel unit, and positioning the support foot in a stowed position.

In one aspect, a control system is provided which determines fluid flow in a suspension system for an agricultural machine by determining total fluid in a closed loop piston system. Fluid is determined using position sensors and a pressure transducers and application of the ideal gas with respect to each accumulator. A closed loop control system can then target an amount of fluid for optimum suspension control.

An air suspension system includes air suspensions (1, 2) performing vehicle height adjustment in response to supply and discharge of air, a compressor (3) compressing air, a tank (4) storing compressed air, a first passage (6) connecting between the delivery side of the compressor and the tank, and a second passage (7) connecting between the delivery side of the compressor and the air suspensions. A first dryer (10) is provided in the middle of the first passage to dry air flowing through the first passage. A second dryer (11) is provided in the middle of the second passage to dry air flowing through the second passage. Thus, compressed air generated from ambient air sucked in by the compressor can be dried by the second dryer and supplied directly into the air chambers of the air suspensions.

A vehicle height adjustment apparatus includes a control device. The control device controls the opening degree of the solenoid valve to allow a movement amount of the support member to reach a movement amount target value that corresponds to the vehicle height set in advance, in accordance with the weight applied to the vehicle. The control device controls the opening degree of the solenoid valve to change the movement amount of the support member based on a difference between a value based on the information related to the vehicle height and a vehicle height-related target value, on condition that the movement amount of the support member reaches the movement amount target value and the value based on the information related to the vehicle height obtained by the information obtaining device does not reach the vehicle height-related target value that corresponds to the vehicle height set in advance.

In one aspect, a control system is provided which determines fluid flow in a suspension system for an agricultural machine by determining total fluid in a closed loop piston system. Fluid is determined using position sensors and a pressure transducers and application of the ideal gas with respect to each accumulator. A closed loop control system can then target an amount of fluid for optimum suspension control.

In one aspect, a suspension control system is provided for dynamically adjusting pistons located proximal to wheels of an agricultural machine to account for tire deflection or squat with varying loads. Articulation, pitch, roll and/or machine height can be determined from pressure measurements on the machine to apply such tire height corrections. For sprayers, this allows controlling clearance and suspension height to maintain the boom parallel to the ground to prevent damage.

In one aspect, a suspension control system is provided for dynamically adjusting pistons located proximal to wheels of an agricultural machine to substantially equalize distribution of weight of the machine at each wheel and/or provide a substantially constant desired orientation of the machine above a ground surface thereby protecting laterally extending sprayer booms from contacting the ground. Articulation, pitch, roll and/or machine height can be determined from piston measurements on the machine to apply such height corrections. For sprayers, this allows controlling clearance and suspension height to maintain the boom parallel to the ground to prevent damage.

Technology is provided for a pneumatic anti-roll system for use on a vehicle suspension. The pneumatic anti-roll system includes left and right side air springs connectable between a chassis of the vehicle and an axle of the vehicle suspension. Left and right side height control valves are mounted to the chassis and left and right side linkages connect between the left and right side height control valves and corresponding left and right end portions of the axle. Left and right side control air lines connect between the left and right side height control valves and corresponding left and right side air springs, respectively.

Disclosed herein is a pneumatic adjustment apparatus for a vehicle. The pneumatic adjustment apparatus includes a block including a flow path formed therein, the flow path being configured for a fluid to move through the block, a compressor coupled to the block and configured to communicate with the flow path and to compress the fluid, a driver coupled to the block, connected to the compressor, and configured to drive the compressor, and a controller coupled to the block and configured to open and close the flow path.