Raise Cutting Deck
A four section gear pump is coupled to the piston (trac- tion) pump. The third gear pump section supplies hy- draulic flow to the lift/lower control valve and the steering control valve. Hydraulic flow from this pump section is delivered to the two circuits through a proportional flow divider. The gear pump takes its suction from the hy- draulic reservoir.
When the cutting deck is in a stationary position, flow from the gear pump is
To raise the cutting deck, the center lift lever on the lift/ lower control valve is pulled to allow valve shift in the lift/ lower control valve. This valve change allows hydraulic pressure to the rod end of the front deck lift cylinders, causing the cylinders to retract. As the cylinders retract, the cutting deck raises. Oil from the piston end of the cyl- inders returns to the hydraulic reservoir. When the lift le- ver is released, the lift cylinders and cutting deck is held in position.
To raise a wing deck, the appropriate lift lever on the lift/ lower control valve is pulled to allow valve shift in the lift/ lower control valve. This valve change allows hydraulic pressure to the piston end of the wing deck lift cylinder and causes the cylinder shaft to retract, raising the wing deck. Oil from the rod end of the cylinder flows to the traction charge circuit. When the lift lever is released, the lift cylinder and wing deck is held in position.
An adjustable counterbalance valve (CB) in the counter- balance manifold maintains back pressure on the deck lift cylinders to allow some of the cutting deck weight to be transferred to the traction unit to improve traction. A relief valve located in the lift/lower control valve limits lift/ lower circuit pressure to 1500 PSI (103 bar). Excess cir- cuit flow is routed to the oil filter and then to the traction charge circuit.
System
Hydraulic
Groundsmaster | Page 4 | Hydraulic System |
