An air supply control arrangement for a heavy-duty vehicle comprising a lift axle is provided. An electronically controlled brake valve device allows, when open, pressurized air to be passed to the brake chamber of the lift axle. A pressurized air source supplies pressurized air to the electronically controlled brake valve device along a supply passage. A pilot control valve provided between the pressurized air source and the electronically controlled brake valve device can restrict air flow through the supply passage. A pressure-responsive element actuates the pilot control valve when the pressure in the lift bellow is increased so that the lift axle is raised to a lift condition. The pressure-responsive element closes the pilot control valve. When the pressure in the lift bellow is reduced so that the lift axle is lowered to a ride condition then the pressure-responsive element is deactivated to allow opening of the pilot control valve.

A shock absorber includes a gas spring cylinder containing a piston moveable between an extended position and a compressed position within the gas spring cylinder. A mechanical actuator is arranged whereby a bleed port is automatically closed when the gas spring is compressed to a predetermined position corresponding to a desired sag setting. In one embodiment, the position corresponds to a predetermined sag setting whereby the gas spring is partially compressed. In another embodiment, a proper sag setting is determined through the use of a processor and sensor that in one instance measure a position of shock absorber components to dictate a proper sag setting and in another instance calculate a pressure corresponding to a preferred sag setting.

An air management system and method are provided. The system includes a pressurized air source. A manifold block is coupled to the pressurized air source and includes a plurality of suspension valves in fluid communication with the pressurized air source for controlling air flow to and from a plurality of air springs. An accumulator is coupled to the manifold block for storing air. An accumulator valve is in fluid communication with the plurality of suspension valves and the accumulator to allow exhausted air from the plurality of air springs into the accumulator. An electronic control unit is electrically coupled to the plurality of suspension valves and the accumulator valve for controlling a sequence of operating the accumulator valve and the plurality of suspension valves to provide enhanced exhaust flow from the plurality of air springs to maintain the vehicle in a level orientation while lowering the vehicle.

A leveling valve (101) for discharging and supplying air from and to a plurality of utilization elements (205a,b), in particular pneumatic suspension bellows, includes a valve arrangement (103) for directing air between a source (207) of pressurized air, an exhaust port (3) and the utilization elements (205a,b), and a supply port (1) in fluid communication with the valve arrangement (103) and the source (207) of pressurized air. A check valve (5) is mounted upstream of the valve arrangement (103) and is configured to allow fluid flow from the supply port (1) towards the valve arrangement (103) and to block fluid flow from the valve arrangement (103) through the supply port (1).

A leveling valve (101) for discharging and supplying air from and to a plurality of utilization elements (205a, b), in particular pneumatic suspension bellows, includes a valve arrangement (103) for directing air between a source (207) of pressurized air, an exhaust port (3) and the utilization elements, a supply port (1) in fluid communication with the valve arrangement (103) and the source (207) of pressurized air, and an exhaust port (3) having an exhaust air channel (a) for discharging exhaust air. The exhaust port (3) includes at least one air-permeable damping element, which is at least partly positioned within the exhaust air channel (a).

A method of setting the rides height of the air springs and air pressures of the tires, including receiving a user selected setting or preprogrammed ride height settings; sensing a ride height of, and air pressure within, each of the air springs; determining the weight of the vehicle based on the sensed ride height and air pressure within each of the air springs; providing specified ride heights for the left and right front and rear air springs; determining specified air pressures for the left and right front and rear tire inflators, based upon the determined weight of the vehicle and selected setting; inflating the left and right front and rear air springs to the specified ride heights; and inflating the left and right front and rear tires to the specified air pressures.

In an air suspension system, starting of a compressor is facilitated in a condition in which there exists a pressure difference. There is provided an air suspension system in which air compressed by a compressor is supplied to a plurality of air chambers provided between a vehicle body side and a wheel side and configured to perform vehicle height adjustment in accordance with the supply and discharge of air. The compressor has a needle connected to a piston and extending in a moving direction of the piston, and an armature reciprocating the needle in the moving direction of the piston.

A compressed air supply installation for operating an air suspension installation of a vehicle includes an air supply unit configured to supply air, an air compression unit configured to compress air, a bleeding line, and a compressed air supply line. The bleeding line includes a bleeding valve arrangement in the form of a controllable solenoid valve arrangement comprising a magnetic part and a pneumatic part actuatable directly via the magnetic part, and a bleeding port for bleeding air. The compressed air supply line includes an air dryer, and a compressed air port for supplying the pneumatic installation with compressed air. The pneumatic part is open in an unactivated state of the magnetic part of the solenoid valve arrangement. The pneumatic part is open in a branch line of the compressed air supply line between a pressure-side valve port and a control-side valve port of the branch line.

A compressor system for generating compressed air for a compressed air supply system in a vehicle. The compressor system includes a brushed direct current electric motor (BDC electric motor); a compressor configured to be driven by the BDC electric motor; and a control unit for controlling the BDC electric motor and allocated to the BDC electric motor so as to delimit an operating current of the electric motor. A free-running current path is allocated to the control unit, the free-running current path being configured to delimit the operating current of the electric motor in a variable manner. A switch controller is allocated to the control unit, the switch controller being configured to specify a switched-on time period (t_ON) and/or a switched-off time period (t_OFF) for the electric motor in a variable manner.

An air source device includes: a tank; a compressor; an intake valve; and an ECU configured to acquire an intake amount, which is an amount of air sucked from an outside and supplied to the tank by the compressor, based on an increasing amount of a tank pressure, which is a pressure of the air accommodated in the tank, the increasing amount being an increasing amount from a time point when the intake valve is estimated to be changed from a closed state to an opened state.