A hydrostatic variable displacement unit is provided having a swash plate
which serves to adjust the stroke of displacement pistons in a cylinder
block and can be pivoted in its angular position by means of a servo
system, the servo system having at least one servo piston with two
servo-piston end surfaces which are in each case assigned a servo
cylinder and a servo-piston rear surface, and the servo cylinders, by
means of the assigned servo-piston end surfaces, in each case bounding a
servo-cylinder pressure space. The servo piston is acted upon by a spring
arrangement having at least one spring arranged outside the
servo-cylinder pressure space and clamped between two spring plates. The
two spring plates are acted upon by the springs in the direction of a
stop of the particular servo cylinder that is situated on its side such
that in the neutral position, the spring plates bear against the
servo-piston rear surfaces and against the stop of the particular servo
cylinder.