Patent ID: 11946462
Assignee: DANFOSS POWER SOLUTIONS INC.
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 13:
14. A method for controlling the displacement volume of a hydraulic axial piston unit comprising:
a rotational group for driving or being driven by a driving shaft, and
a displacement element tiltable for adjusting the displacement volume of the rotational group,
wherein the rotational group comprises a rotatable cylinder block in which working pistons are mounted reciprocally moveable in cylinder bores for conveying hydraulic fluid from a kidney-shaped inlet port to a kidney-shaped outlet port located on a valve segment of the hydraulic axial piston unit,
said hydraulic axial piston unit further comprising:
at least two control ports each located on the valve segment between the respective circumferential ends of the kidney-shaped inlet port and the kidney-shaped outlet port, wherein the control ports can be brought sequentially in fluid connection with the cylinder bores when the cylinder block rotates,

wherein the at least one hydraulic fluid injector is connected fluidly to both control ports via two control lines connected to the outlets of a hydraulically, electro-mechanically or pneumatically operable two-position switching valve, wherein the switching valve selects in each position one of the two control lines for injecting of hydraulic fluid by means of the injector and the other control line of the two control lines for draining hydraulic fluid from the other control port,
the method comprising the following steps:
injecting by means of a hydraulic fluid injector hydraulic fluid with a variably adjustable pressure level via one control port into passing cylinder bores during a time span when the cylinder bores at least partially overlaps with the control port,
draining hydraulic fluid via the other control port from the passing cylinder bores.