A hydraulic system includes a pump having a pump outlet, a tank configured to supply fluid to the pump, a hydraulic motor coupled to an air compressor that is configured to supply compressed air to an air brake, a steering gear having an inlet workport and an outlet workport, and a compressor bypass valve. The compressor bypass valve is selectively movable between a first position where fluid flow is provided from the pump outlet to both the hydraulic motor and the inlet workport of the steering gear and a second position where the fluid flow from the pump outlet bypasses the hydraulic motor and is supplied to the inlet workport of the steering gear.

A compressor module has a compressor and a speed-controlled brushless electric motor for driving the compressor. A motor current is produced during operation of the electric motor. The electric motor is assigned a motor electronics system with an electronic commutator and a speed controller. The compressor module is connected to or has an electronic control unit. The control unit is configured to specify, depending on the mean motor current, one of at least two different target speeds for the electric motor, specifically at least a predefined first target speed and a predefined second target speed, which is lower than the predefined first target speed, and to change over from specifying the predefined first target speed to specifying the predefined second target speed when the mean motor current reaches or exceeds a specified motor current limit value. The compressor module can be for a compressed-air supply system of a vehicle.

A compressor module has a compressor and a speed-controlled brushless electric motor for driving the compressor. A motor current is produced during operation of the electric motor. The electric motor is assigned a motor electronics system with an electronic commutator and a speed controller. The compressor module is connected to or has an electronic control unit. The control unit is configured to specify, depending on the mean motor current, one of at least two different target speeds for the electric motor, specifically at least a predefined first target speed and a predefined second target speed, which is lower than the predefined first target speed, and to change over from specifying the predefined first target speed to specifying the predefined second target speed when the mean motor current reaches or exceeds a specified motor current limit value. The compressor module can be for a compressed-air supply system of a vehicle.

An electro-hydraulic brake system includes a master cylinder (MC) configured to supply fluid into a first MC fluid passageway in response to pressing force on a brake pedal; a pressure supply unit (PSU) assembly having a PSU motor coupled to a ball screw actuator, a PSU housing defining a piston bore having a terminal end opposite the PSU motor, and a PSU piston dividing the piston bore into a first chamber and a second chamber and movable by the ball screw actuator, with each of the first chamber and the second chamber containing a hydraulic fluid; and a backup pump assembly including a pump for supplying the brake fluid to at least one of the wheel brakes. The ball screw actuator includes an actuator nut assembly having a plurality of ball bearings each disposed within the piston bore and submerged in the hydraulic fluid.

An electro-hydraulic brake system includes a master cylinder (MC) configured to supply fluid into a first MC fluid passageway in response to pressing force on a brake pedal; a pressure supply unit (PSU) assembly having a PSU motor coupled to a ball screw actuator, a PSU housing defining a piston bore having a terminal end opposite the PSU motor, and a PSU piston dividing the piston bore into a first chamber and a second chamber and movable by the ball screw actuator, with each of the first chamber and the second chamber containing a hydraulic fluid; and a backup pump assembly including a pump for supplying the brake fluid to at least one of the wheel brakes. The ball screw actuator includes an actuator nut assembly having a plurality of ball bearings each disposed within the piston bore and submerged in the hydraulic fluid.

An air management system of a vehicle includes an air compressor configured to generate compressed air; an air processing device configured to purify and dehumidify the compressed air discharged from the air compressor; a first air tank configured to store the compressed air passing through the air processing device; an air brake device configured to perform a braking operation of the vehicle using the compressed air stored in the first air tank; a second air tank configured to store exhausted air used for the braking operation and discharged; a solenoid valve connected to each of the second air tank and the air processing device through pipes and configured to control movement of the exhausted air between the second air tank and the air processing device; and a control unit configured to control opening or closing of the solenoid valve.

An air management system of a vehicle includes an air compressor configured to generate compressed air; an air processing device configured to purify and dehumidify the compressed air discharged from the air compressor; a first air tank configured to store the compressed air passing through the air processing device; an air brake device configured to perform a braking operation of the vehicle using the compressed air stored in the first air tank; a second air tank configured to store exhausted air used for the braking operation and discharged; a solenoid valve connected to each of the second air tank and the air processing device through pipes and configured to control movement of the exhausted air between the second air tank and the air processing device; and a control unit configured to control opening or closing of the solenoid valve.

A pneumatic system comprises a compressor and an air dryer for supplying a first set of consumers in a main circuit having multi-circuit protection valve system and at least one further consumer is a subsidiary circuit. A selection valve is used to control the coupling of the output of the air dryer to either the main circuit or the subsidiary circuit. The supply is provided to the subsidiary circuit only when a fluid pressure associated in the main circuit exceeds a threshold.

A pneumatic system comprises a compressor and an air dryer for supplying a first set of consumers in a main circuit having multi-circuit protection valve system and at least one further consumer is a subsidiary circuit. A selection valve is used to control the coupling of the output of the air dryer to either the main circuit or the subsidiary circuit. The supply is provided to the subsidiary circuit only when a fluid pressure associated in the main circuit exceeds a threshold.

A pneumatic system comprises a first compressor and associated first air dryer for supplying dried air to a first set of consumers in a main circuit and a second compressor and associated second air dryer for supplying dried air to at least one further consumer through a subsidiary circuit. A protection valve system is provided in the main circuit between the first air dryer and the first set of consumers. A fluid flow path is provided between the main and subsidiary circuits which is selectively openable or closable by a coupling valve to enable the subsidiary circuit to be supplied with pressurized air from the main circuit or to isolate the main and subsidiary circuits.