Brake systems with a plurality of single-chamber master cylinders
AssigneeZF Active Safety US Inc.
InventorBlaise J. Ganzel
Life of this patent
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Abstract
A brake system includes a reservoir and first and second motor-driven master cylinders. An electronic control unit is provided for controlling at least one of the first and second master cylinders responsive to at least one brake pressure signal. A secondary power transmission unit is configured for selectively providing pressurized hydraulic fluid at first and second PTU outputs for actuating first and second pairs of wheel brakes in at least one of a normal non-failure braking mode and a backup braking mode. Each of the first and second PTU outputs provides fluid to a corresponding one of the first and second pairs of wheel brakes. The secondary power transmission unit is directly fluidly connected to the reservoir.
Claims16
A brake system for actuating a plurality of wheel brakes comprising first and second pairs of wheel brakes, the system comprising:
- a reservoir;
- first and second motor-driven master cylinders, each master cylinder being operable during a normal non-failure braking mode by actuation of an electric MC drive motor of the master cylinder to generate brake actuating pressure at a respective first or second MC output for hydraulically actuating a corresponding one of the first and second pairs of wheel brakes;
- a first traction control iso valve hydraulically interposed between the first master cylinder and the first pair of wheel brakes via the first MC output;
- a second traction control iso valve hydraulically interposed between the second master cylinder and the second pair of wheel brakes via the second output;
- at least two brake pressure sensors, each brake pressure sensor being associated with a selected one of the first and second pairs of wheel brakes for sensing hydraulic pressure at the corresponding pair of wheel brakes and responsively producing a brake pressure signal;
- an electronic control unit for controlling at least one of the first and second master cylinders responsive to at least one of the brake pressures signals;
- and
- a secondary power transmission unit configured for selectively providing pressurized hydraulic fluid at first and second PTU outputs for actuating the first and second pairs of wheel brakes in at least one of the normal non-failure braking mode and a backup braking mode, the secondary power transmission unit including an electric PTU motor configured to selectively pressurize the hydraulic fluid by transmitting rotary motion to at least two pump pistons, each pump piston providing pressurized hydraulic fluid to a corresponding one of the first and second PTU outputs, each of the first and second PTU outputs providing fluid to a corresponding one of the first and second pairs of wheel brakes;
- wherein the secondary power transmission unit is directly fluidly connected to the reservoir.
Dependencies are inferred from the claim text.