Variable displacement pump

Axial piston is a collective term for a used in the hydraulic unit ( axial piston pump, axial piston motor ). An axial piston pump converts mechanical energy (torque, speed) into hydraulic energy (flow, pressure). An axial piston motor is an axial piston pump in construction very similar, but uses hydraulic energy (flow, pressure) into mechanical energy (torque, speed) to.

A big advantage of axial piston machines over other types is the great stability and good internal seal against high pressures are possible. The range standard- axial piston reaches 1.2 to 1000 kW at speeds up to 12,000 rpm -1.

Axial piston machines usually have odd numbers of cylinders to prevent oscillations (eg, 6 cylinder would yield 6 pressure peaks per revolution, 7 cylinder 14 resulting pressure peaks per revolution). Usual cylinder numbers are 7 or 9 cylinders. Basically, three types are distinguished for axial piston:

  • Oblique axis machine; depending on the tilt angle of the drive and pump axis lead arranged in a rotating cylinder piston to stroke.
  • Swash plate machine; depending on the tilt angle of a sliding disk lead arranged in a rotating cylinder piston to stroke.
  • A swash plate machine; Reversal of the principle of the swashplate machine. A relative to the axis inclined, rotating disk forces the non-rotating piston to stroke movements. Swash plate machines are usually fixed displacement pumps, because of the swivel angle of the swash plate can not be adjusted.

Cause of the use of the swash plate is above all the possible mechanical drive-through, which allows multiple pumps on one axis. Bent axis motors usually have a higher efficiency than the swash plate motors. A difference in the bent axis motors, the pivoting dar. So-called large-angle units permit a wide ratio spread in the hydrostatic drive. Motors in standard design in turn allow zero angle by their extra features.

Today, constant and variable displacement machines are mostly used in bent axis design; Variable but mostly used as swashplate machine.

  • Hydraulic
  • Piston engine