Radial piston pump

A radial piston pump, for use with a motor vehicle brake system with slip control, includes two parallel working circuits (1, 2) drivable by the same drive motor (6). The working pressure of the first working circuit (1) is limited to a preset value. Above said value only the second working circuit (2) is effective. The advantage is that with low power consumption of the drive motor the delivery rate in the low pressure range is relatively high, while it is relatively low in the case of high pressures, as is required in brake systems with slip control. … As shown the pumps have a common rotor (5) and journal (7) bearing inlet conduit (19) and outlet conduit (18), but have different eccentric cam rings (3, 4). … Pistons (12, 13) of circuit (1) are a loose fit in their cylinders (8, 9) and so provide a throttled connection between pressure and section sides. The preset pressure at which circuit (1) ceases to be effective is that pressure at which all the pressure fluid is conveyed past pistons (12, 13) back to the suction side. … Optionally the output pressure may be used to shut a valve to cut off the supply of fluid to circuit (1). ……