Radial piston pump, method for operating a radial piston pump, and steering system

A method for operating a radial piston pump for delivering a pressure medium to a first consumer, wherein the radial piston pump has a housing in which cylinder bores are arranged radially to a longitudinal axis and in each of which a respective radially displaceable first piston is arranged, wherein the pistons form a first piston row lying in a radial plane, and wherein the first pistons are set in a linearly oscillating reciprocating motion by rotation of an eccentric shaft mounted in the housing for rotation about the longitudinal axis, and wherein the pressure medium flows into cylinder chambers through suction openings of the first pistons in the region of a bottom dead center of the motion, from a suction chamber which is supplied with the pressure medium through a suction port under a vacuum created by the movement of the first pistons towards a bottom dead center of the motion, and wherein the pressure medium is delivered via pressure openings to a first pressure outlet on movement of the first pistons towards the top dead center, and wherein at least one further piston row is provided planar-parallel to the first piston row, and further cylinder bores are provided in the housing, in each of which a respective second piston of the further piston row is radially displaceably arranged, and the second pistons of the further piston row are set in a linearly oscillating reciprocating motion by rotation of the eccentric shaft, whereupon the pressure medium delivered by the first piston row is supplied to the first consumer and the pressure medium delivered by the further piston row is supplied to a second consumer, the first consumer being a first steering system of a first steerable wheel axle of a vehicle and the second consumer being a steering system of a second steerable wheel axle of the vehicle.

A steering system for a vehicle of the type having at least a first steerable wheel axle which in normal operation can be deflected by a first steering device and a second steerable wheel axle which in normal operation can be deflected by a second steering device, said system, comprising:

• an emergency pump configured as a radial piston pump, the radial pump including:
• (a) an eccentric shaft having a longitudinal axis;
• (b) a housing having first cylinder bores which are arranged radially to the longitudinal axis, the housing further having (i) a suction port supplied with a pressure medium, (ii) a suction chamber which is supplied with the pressure medium through the suction port and (iii) a first pressure outlet, and
• (c) a respective first piston disposed radially displaceably in each of the first cylinder bores, the first pistons being arranged in a first piston row which lies in a radial plane, each of the first pistons having a respective suction opening, the eccentric shaft being mounted in the housing for rotation about the longitudinal axis for moving the first pistons in a first linearly oscillating reciprocating motion having a top dead center and a bottom dead center, and wherein, in a region of the bottom dead center of the first linearly oscillating reciprocating motion, the pressure medium flows into cylinder chambers through the suction openings of the first pistons, and wherein the pressure medium flows out of the cylinder chambers to the first pressure outlet through pressure openings owing to movement of the first pistons towards the top dead center of the first linearly oscillating reciprocating motion;
• and wherein further cylinder bores are provided in the housing and a respective second piston is disposed radially displaceably in each of the further cylinder bores, the second pistons being arranged in at least one further piston row which is located planar-parallel to the first piston row, and wherein the eccentric shaft moves the second pistons of the further piston row in a second linearly oscillating reciprocating motion;
• and
• wherein said system further comprises first pressure lines to supply the pressure medium delivered by the first piston row to a wheel steering gear or a steering cylinder of the first steering device of the vehicle, and further pressure lines to supply the pressure medium delivered by the further piston row to a wheel steering gear or a steering cylinder of the second steering device of the vehicle.

A radial piston pump for delivering a pressure medium to a consumer, said pump comprising:

• an eccentric shaft having a longitudinal axis;
• a housing having first cylinder bores which are arranged radially to the longitudinal axis, the housing further having (i) a suction port supplied with the pressure medium, (ii) a suction chamber which is supplied with the pressure medium through the suction port, and (iii) a first pressure outlet;
• a respective first piston disposed radially displaceably in each of the first cylinder bores, the first pistons being arranged in a first piston row which lies in a radial plane, each of the first pistons having a respective suction opening, the eccentric shaft being mounted in the housing for rotation about the longitudinal axis for moving the first pistons in a first linearly oscillating reciprocating motion having a top dead center and a bottom dead center, and wherein, in a region of the bottom dead center of the first linearly oscillating reciprocating motion, the pressure medium flows into cylinder chambers through the suction openings of the first pistons, and wherein the pressure medium flows out of the cylinder chambers to the first pressure outlet through pressure openings owing to movement of the first pistons towards the top dead center of the first linearly oscillating reciprocating motion;
• and
• wherein further cylinder bores are provided in the housing and a respective second piston is disposed radially displaceably in each of the further cylinder bores, the second pistons being arranged in at least one further piston row which is located planar-parallel to the first piston row, and wherein the eccentric shaft moves the second pistons of the further piston row in a second linearly oscillating reciprocating motion, and wherein the pressure medium delivered by the first piston row is supplied to a first consumer and the pressure medium delivered by the further piston row is supplied to a second consumer, the first consumer being a first steering system of a first steerable wheel axle of a vehicle and the second consumer being a steering system of a second steerable wheel axle of the vehicle.