U20-3, U25-3 WSM Hydraulic system (Mechanism section)
IV-M-48
c. Operating principle of counter valance valve
The counter balance valve is used to stop the axial piston motor and to prevent it from overrunning. When
the control valve is in the neutral position, because no pressure is applied to the ports P1 and P2, the
ports M1 and M2 (31-1) are blocked by the plunger and check valve (31-2) and therefore the motor does
not rotate.