Kubota M108S, Workshop Manual

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7-M1
M108S, WSM STEERING
1. STRUCTURE
[1] STEERING MECHANISM
This model is provided with a full hydrostatic power
steering. Generally power steerings are divided into 4
types: booster type, integral type, semi-integral type and
full hydrostatic type.
In the full hydrostatic power steering, the steering
controller is connected to the steering cylinder with only
the hydraulic pipe. This steering is actuated by oil
pressure. Accordingly, it does not have mechanical
transmitting parts such as steering gear, pitman arm,
drag link, etc.. Therefore, it is simple in construction.
This steering system consists of the hydraulic pump
(1), steering controller (2), steering cylinder (3),etc..
This power steering system has double-acting safety
valve (11) which restricts maximum pressure in the
power steering cylinder (3).
The full hydrostatic power steering systems are
divided into two types : non-load reaction type and load
reaction type.
They are distinguished by whether the cylinder port is
blocked or not with the controller in neutral. In this
models, load reaction type is used.
With the load reaction type power steering, the
steering wheel returns almost to the straight forward
position as with an automobile when the operator
releases his hands from the steering wheel.
(Reference)
With the non-load reaction type power steering, the
steering wheel maintain their position when the operator
releases his hands from the steering wheel.
Vibration at the wheels is not transmitted to the
steering wheel.
W1012661
NOTE
■
• Refer to “7. STEERING” section in the workshop manual of tractor mechanism (Code No. 9Y021-18201).
(1) Hydraulic Pump
(2) Steering Controller
(3) Steering Cylinder
(4) Gerotor
(5) Check Valve
(6) Control Valve
(7) Regulator Valve
(8) Relief Valve
(9) Steering Wheel
(10) Oil Cooler
(11) Double Acting Safety Valve
(a) To Shuttle Clutch Pack for
Lubrication
(b) To PTO Clutch Pack for
Lubrication
KiSC issued 06, 2007 A