jcb JS220 - Page 445

3 - 3
Section F
Transmission
9803/6400
Section F
3 - 3
Issue 1
Motor/Gearbox
Operation (continued)
Counterbalance Valve
Fig.2 Counterbalance Valve
The counterbalance valve serves to prevent the sudden stoppage of the axial piston motor and control its overrun. When in
neutral, the control valve's pressure is generated at ports P1 or P2 so ports M1 and M2 are blocked by the flange and check
valve so the motor does not rotate.
P
2
P
1
M
2
M
1