Radial piston pump

from Wikipedia, the free encyclopedia
Radial piston pump inside applied
Radial piston pump externally applied

A radial piston pump is an element of fluid technology . In contrast to the axial piston pump, the working pistons of this pump are arranged radially and perpendicular to the drive shaft. The delivery or stroke movement of each individual working piston / displacer is caused by an eccentric located on the pump shaft or an external eccentric.

If the working space of the cylinder is filled from "inside" (e.g. via a hollow shaft), this is referred to as a radial piston pump that is pressurized on the inside (but supported on the outside). If the working space is filled from "outside", one speaks of an externally pressurized radial piston pump (but internally supported).

functionality

For the functionality, the movement of a single working piston should be examined more closely based on the internally pressurized pump:
The outer ring on which the working pistons are supported is in an eccentric position to the hollow shaft in the middle. The extent of the working piston stroke is determined by the amount of eccentricity.
The working piston starts the suction process in the inner dead center (IT). After an angle of rotation of 180 ° this is ended and the working piston space is filled with the medium to be conveyed. The working piston is now in the outer dead center (AT). From this point on, the working piston conveys the medium previously sucked in into the pressure channel of the pump.

properties

This type of piston pump is characterized by the following advantages:

  • favorable degrees of efficiency
  • high load pressures (up to 1000 bar)
  • low high pressure pulsation (due to the small dead volume in the piston chamber)
  • very high loads at the lowest speeds possible due to hydrostatics
  • no axially acting engine forces on the drive bearing
  • long life span

The disadvantage is the larger radial dimensions compared to the axial piston pump , which can, however, be compensated for by the shorter axial design.

Applications

Due to the hydrostatic bearing it is possible that the pumps convey different pressure transmission media. In addition to mineral oils, special fluids such as HFA, HFC, HFD or drilling emulsion can also be pumped.
This results in the following areas of application for radial piston pumps:

  • Machine tools (e.g. conveying cooling lubricants, hydraulic actuating devices)
  • Aggregate construction (e.g. for overload protection of presses)
  • Test bench construction
  • Vehicle sector (e.g. automatic transmission, hydraulic suspension level control in the luxury class)
  • Plastic injection molding and die casting machines
  • Wind turbines

See also

literature

  • Horst-Walter Grollius: Basics of hydraulics . 7th updated edition. Hanser Verlag, Munich 2015, ISBN 978-3-446-44275-7 .
  • Hans-Hermann Franzke: Introduction to machine and system technology . Volume 2: Working machines . Springer Verlag, Berlin Heidelberg, Berlin / Heidelberg 1990, ISBN 978-3-540-50552-5 .

Web links