Piston pump and method for operating a piston pump
AssigneeSchwing GmbH
InventorsAndreas Lehmann, Friedrich Schwing
Life of this patent
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Abstract
The invention relates to a method for operating a piston pump with a differential cylinder drive (1) with at least two differential cylinders (2, 3) for driving at least two conveying pistons movable in conveying cylinders, each conveying piston being driven via an associated differential cylinder (2, 3) of the differential cylinder drive (1) for operating the piston pump, with a hydraulic circuit (4) for driving the differential cylinder drive (1) by the action of hydraulic fluid. The invention also relates to a piston pump for carrying out the method.
Claims19
A method for operating a piston pump with a differential cylinder drive with a first differential cylinder and a second differential cylinder for respectively driving a first conveying piston and a second conveying piston respectively movable in a first conveying cylinder and a second conveying cylinder, the first conveying cylinder being driven via the first differential cylinder of the differential cylinder drive, the second conveying cylinder being driven via the second differential cylinder of the differential cylinder drive, with a hydraulic circuit for controlling the differential cylinder drive and/or for driving the differential cylinder drive by action of hydraulic fluid, the method comprising the following cyclically performed steps:
- suctioning material to be conveyed via the first conveying cylinder by driving the first differential cylinder and simultaneously discharging material to be conveyed via the second conveying cylinder by driving the second differential cylinder;
- pre-compressing the sucked-in material via the first conveying cylinder by driving the first differential cylinder and simultaneously discharging material via the second conveying cylinder by driving the second differential cylinder;
- discharging material via the first conveying cylinder by driving the first differential cylinder and simultaneously suctioning material to be conveyed via the second conveying cylinder by driving the second differential cylinder;
- and
- discharging material via the first conveying cylinder by driving the first differential cylinder and simultaneously pre-compressing the sucked-in material via the second conveying cylinder by driving the second differential cylinder,
- wherein the pre-compressing steps are divided into at least two phases,
- wherein in a first phase the hydraulic circuit causes pre-compression using a first conveying piston speed by controlling the hydraulic fluid at a first volume flow and a first pressure,
- wherein in a second phase the hydraulic circuit causes pre-compressing using a second conveying piston speed, which is lower than the first conveying piston speed, by controlling a second volume flow and a second pressure,
- wherein the second volume flow is lower than the first volume flow and the second pressure is higher than the first pressure.
A piston pump comprising:
- a differential cylinder drive with first and second differential cylinders that are configured and arranged to drive respective first and second conveying pistons that are movable in respective first and second conveying cylinders, each of the first and second conveying pistons arranged to be driven via respective first and second differential cylinders for operating the piston pump, a hydraulic circuit is configured to control the differential cylinder drive and/or to drive the differential cylinder drive by the action of hydraulic fluid,
- wherein the hydraulic circuit is controlled to effect:
- in a first phase, pre-compression of sucked-in material in at least one of the first and second conveying cylinders at a first conveying piston speed by acting on the associated differential cylinder with the hydraulic fluid at a first volume flow and at a first pressure, and
- in a second phase, pre-compression of the sucked-in material in the at least one of the first and second conveying cylinders at a second conveying piston speed, which is lower than the first conveying piston speed, by acting on the associated differential cylinder at a second volume flow and at a second pressure,
- wherein the second volume flow is lower than the first volume flow and the second pressure is higher than the first pressure.
Dependencies are inferred from the claim text.