A vehicle includes wheels, brakes to control speeds of the wheels, and a hydraulic fluid source in fluid communication with the brakes. The vehicle includes a computer storing instructions to determine that speeds of the wheels are zero and actuate the hydraulic fluid source to provide hydraulic fluid to a first set of one or more of the brakes at a first pressure sufficient to maintain the vehicle body at a present position and to provide hydraulic fluid at a volumetric rate to one or more of the brakes not in the first set, and, while providing hydraulic fluid at the volumetric rate to a brake not in the first set, detect second pressures of the brake not in the first set. The instructions include instructions to determine a volume-pressure curve for the brake not in the first set based on the volumetric rate and the second pressures.

This compressed air generation system (12) for an automotive vehicle (V) comprises: —a turbocompressor (4) feeding an internal combustion engine (2) of the automotive vehicle (V) with compressed air, —an air compressor (8), —at least one compressed air tank (10) connected to an outlet pipe (82) of the air compressor (8), the air compressor (8) comprising an inlet pipe (80) fed with compressed air from the turbocompressor (4). The compressed air generation system (12) comprises a pressure regulator (14) placed downstream the turbocompressor (4) and upstream the air compressor (8) and which limits the pressure (P8) of the compressed air fed from the turbocompressor (4) to the air compressor (8) to a first threshold (T1).

This compressed air generation system (12) for an automotive vehicle (V) comprises: —a turbocompressor (4) feeding an internal combustion engine (2) of the automotive vehicle (V) with compressed air, —an air compressor (8), —at least one compressed air tank (10) connected to an outlet pipe (82) of the air compressor (8), the air compressor (8) comprising an inlet pipe (80) fed with compressed air from the turbocompressor (4). The compressed air generation system (12) comprises a pressure regulator (14) placed downstream the turbocompressor (4) and upstream the air compressor (8) and which limits the pressure (P8) of the compressed air fed from the turbocompressor (4) to the air compressor (8) to a first threshold (T1).

A hydraulic/mechanical braking system for a vehicle comprises a cam (128) keyed onto a transmission shaft or a trailing wheel and at least two hydraulic cylinder assemblies (126,129) including a cam follower (127). A hydraulic circuit (C) connects the hydraulic cylinder assemblies together. A master brake valve (113) controls the flow of fluid in the circuit. Actuation of the master brake valve (113) obstructs the flow of fluid and hence the reciprocation of the hydraulic cylinder assemblies, forcing the cam following against the cam to resist rotation.

A hydraulic/mechanical braking system for a vehicle comprises a cam (128) keyed onto a transmission shaft or a trailing wheel and at least two hydraulic cylinder assemblies (126,129) including a cam follower (127). A hydraulic circuit (C) connects the hydraulic cylinder assemblies together. A master brake valve (113) controls the flow of fluid in the circuit. Actuation of the master brake valve (113) obstructs the flow of fluid and hence the reciprocation of the hydraulic cylinder assemblies, forcing the cam following against the cam to resist rotation.

An electrical motor vehicle vacuum pump arrangement includes a housing assembly which includes an inlet opening arrangement having an inlet opening, an outlet opening arrangement having an outlet opening and an outlet channel, a pump unit having a pump rotor housing with an inlet-side end wall, an outlet side end wall, and a pump rotor housing part arranged therebetween, a drive motor having a motor rotor and a motor stator, sound absorption elements, and a sealing connected to the pump rotor chamber and directed towards the outlet opening. The outlet opening arrangement is connected to one of the sound absorption elements. The outlet channel of the outlet opening arrangement is closed relative to the drive motor and the pump unit. The outlet channel of the outlet opening arrangement, when viewed in a direction of the outlet opening, comprises at least one abrupt change in cross-section.

An electrical motor vehicle vacuum pump arrangement includes a housing assembly which includes an inlet opening arrangement having an inlet opening, an outlet opening arrangement having an outlet opening and an outlet channel, a pump unit having a pump rotor housing with an inlet-side end wall, an outlet side end wall, and a pump rotor housing part arranged therebetween, a drive motor having a motor rotor and a motor stator, sound absorption elements, and a sealing connected to the pump rotor chamber and directed towards the outlet opening. The outlet opening arrangement is connected to one of the sound absorption elements. The outlet channel of the outlet opening arrangement is closed relative to the drive motor and the pump unit. The outlet channel of the outlet opening arrangement, when viewed in a direction of the outlet opening, comprises at least one abrupt change in cross-section.

A monitoring method of a compressor for a railway braking system is described, the railway braking system comprising an air generation and treatment module AGTU which includes a compressor, a main tank arranged to supply a main pipe adapted to distribute compressed air to at least one braking subsystem which comprises an auxiliary tank arranged to supply a braking control system; the monitoring process being characterized in that it comprises the steps of: monitoring a behavior of at least one pressure value measured downstream of the main tank or measured at the outlet of the auxiliary tank; deriving the use and/or state of health of the compressor exclusively on the basis of the time behavior of the measured pressure value.

A piston pump includes: a sleeve housing which is provided with a discharge hole and defines a bore; a piston which has an inlet flow passage for drawing oil into the bore and is reciprocally movably inserted into the bore; an inlet valve which is configured to open/close the inlet flow passage; an outlet valve cover which is coupled to the sleeve housing to surround a portion at which the discharge hole is formed; an outlet valve which is configured to open/close the discharge hole; and a sealing member which is interposed between the sleeve housing and the piston to provide a sealing therebetween. The sealing member is provided with a separation prevention protrusion against which the piston is blocked to prevent a separation of the piston.

A pressure medium assembly, in particular for providing and regulating a pressure in a brake circuit of a slip-controllable brake system of a motor vehicle, includes a housing block and an electronic controller. The housing block includes a pump configured to be actuated by a drive motor and a valve, which are actuated by the controller. The controller is secured to an outer face of the housing block and has a device flange that is paired with a housing flange formed on the housing block. The flanges fix the housing block and the controller together. The housing flange protrudes radially outwards relative to a housing block peripheral side facing the housing flange such that the entire upper face of the housing block is available for a controller housing. This configuration additionally allows the use of a printed circuit board which is free of open recesses on the peripheral side.