3. Operation of a basic hydraulic
system
The hydraulic system provides the “muscle” for
controlling various operations. Hydraulic
functions are :
a. Steering *
b. Brakes *
c. Transmission
d. Implement control *
e. Remote cylinders
f. Hydraulic motors
Hydraulic fluid serves as power transmitting medium
and also the system’s lubricant and coolant
4. Hydraulic Steering
Hydraulic valve controlled by the steering wheel
and hydraulic pistons which assist the steering
mechanism in turning the wheels
6. Implement Control
Two types used on tractor :
1.Power lift (Rockshaft)
Used in control mounted implements
Is controlled either manually using a control lever or
automatically by load sensing
2.Remote control
Usually placed on a pull type implement to control a
function such as raising the plow bottoms
7. Raising Plow Using Control Lever
The plow hit hard ground and the operator wants to raise it
slightly
Moves the control lever to the front (1)
This pivot the cam follower (2) forward and presses it
against rod (3) which opens valve (4)
Pressure oil is now admitted to the cylinder, forcing piston
(5) to the rear
The piston pushes against the shaft arm (6), rotating
rockshaft (7) and lift arm (8) upward
The lift arm is attached to the plow and so the plow is
raised slightly to help it pass through the hard ground
8. Automatic Draft Control Raises
The Plow
The plow hit the hard ground (1) and load control shaft (3)
is pulled rearward by draft links (2)
As a result, load control arm (12) is pivoted against cam
follower (4)
The cam follower pushes on the rod (5) which open valve
(6) and admits pressure to cylinder (7)
The cylinder piston pushes against the arm (8), rotating
rockshaft (9) and lift arm (10) upward
The lift arm is attached to the plow and so raises the plow
slightly to help it pass through the hard ground
The regular depth of the plow can be set at the control
lever. The plow will stay at this depth unless a signal is
given by the load sensing device
