A brake system comprises an electronic stability control (ESC) module defining a first interconnect passage, and a pressure supply unit (PSU) module defining a second interconnect passage in fluid communication with the first interconnect passage. The ESC module includes a first pump configured to transfer brake fluid from the PSU module and to a plurality of wheel brakes, and a prime valve configured to selectively control fluid communication between the first interconnect passage and an inlet of the first pump. The PSU module includes a second pump configured to transfer the brake fluid from a fluid reservoir to the first interconnect passage, and a bypass fluid passage from the fluid reservoir to the ESC module with an inline check valve allowing fluid flow through the bypass fluid passage from the fluid reservoir and to the ESC module while blocking fluid flow in an opposite direction.

A valve unit for modulating pressure in a compressed-air brake system comprises an inlet valve (6) and an outlet valve (7) configured as diaphragm valves, a brake pressure output (4) configured to be connected to or shut off from a brake pressure input (3) or a vent output (5), two pilot valves (8, 9) configured as 3/2-way solenoid valves, and a respective control chamber (31, 32) adjacent to the diaphragm (17, 18) of the diaphragm valves (6, 7). The diaphragms (17, 18) are each clamped between two housing parts (11, 14; 11, 14) via a respective ring bead (22, 23) placed in a housing-side ring groove (20, 21; 20, 21). In order to avoid damaging the diaphragms (17, 18), an annular continuous or partially interrupted recess (54) is arranged in the ring groove (20, 21) or immediately adjacent to the ring groove to receive displaced bead material from the diaphragm (17).

A valve unit for modulating pressure in a compressed-air brake system comprises an inlet valve (6) and an outlet valve (7) configured as diaphragm valves, a brake pressure output (4) configured to be connected to or shut off from a brake pressure input (3) or a vent output (5), two pilot valves (8, 9) configured as 3/2-way solenoid valves, and a respective control chamber (31, 32) adjacent to the diaphragm (17, 18) of the diaphragm valves (6, 7). The diaphragms (17, 18) are each clamped between two housing parts (11, 14; 11, 14) via a respective ring bead (22, 23) placed in a housing-side ring groove (20, 21; 20, 21). In order to avoid damaging the diaphragms (17, 18), an annular continuous or partially interrupted recess (54) is arranged in the ring groove (20, 21) or immediately adjacent to the ring groove to receive displaced bead material from the diaphragm (17).

An object of the present invention is to provide a pump device that is capable of improving a discharge performance. A first orifice 301 that is provided on a discharge oil passage (a pipe 12) of a pump 2 and a second orifice 302 that, when a flow amount Q becomes greater than a predetermined flow amount Q1, allows pass of brake fluid are provided.

An electrically controlled valve for electrically controlling air brakes by releasing pressurized air at a controlled rate. The electrically controlled valve is useful for connecting a trailer with air brakes to a standard electrical connector on a towing vehicle that provides a proportional braking signal. The proportional signal is sent to the electrically actuated valve and a controller within the valve process the signal. When electrically actuated valve receives the proportional braking signal from the towing vehicle representing no braking force, electrically actuated valve to produce no air pressure to the air brake. When the electrically actuated valve receives the proportional braking signal from the towing vehicle representing full braking force, the electrically actuated valve provides air to the air brakes corresponding to full braking force of the air brakes.

A brake system comprises an electronic stability control (ESC) module defining a first interconnect passage, and a pressure supply unit (PSU) module defining a second interconnect passage in fluid communication with the first interconnect passage. The ESC module includes a first pump configured to transfer brake fluid from the PSU module and to a plurality of wheel brakes, and a prime valve configured to selectively control fluid communication between the first interconnect passage and an inlet of the first pump. The PSU module includes a second pump configured to transfer the brake fluid from a fluid reservoir to the first interconnect passage, and a bypass fluid passage from the fluid reservoir to the ESC module with an inline check valve allowing fluid flow through the bypass fluid passage from the fluid reservoir and to the ESC module while blocking fluid flow in an opposite direction.