TYM T303HST, Руководство по ремонту

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SECTION 5. THEORY OF OPERATION
HYDROSTATIC SYSTEM
Function:
The hydrostatic system provides a means to transfer
Power from the engine to the final final drive to the
wheels.it also provides infinitely variable speed
control,forward or reverse,by foot pedal operation.
Principles of Operation:
The hydrostatic system is a closed loop fluid power
system that consist of a charge pump on the left
front side of the engine.and an EATON piston
pump/motor assembly, which is driven by a
Flexible coupler Attached to the flywheel.
Fluid flow is controlled by by changing the angle of
the cam plate. This angle is controlled by the
Charge pump
The charge pump is a gear type positive
displacement pump mounted to the right front
side of the engine.
This pump provides pressurized fluid to the SCU
(Steering Control Unit). Return oil from the SCU
is routed through the filter mounted to the front
of the back plate, and then into the hydrostatic
pump to provide replacement fluid to the
hydrostatic pump.
Hydrostatic Motor
The hydrostatic motor is an EATON high torque
axial piston motor.The motor is located on the
rear of the back plate.The hydrostatic motor
drives the input shaft for a three speed range gear the cam plate. This angle is controlled by the
operator through a mechanical linkage.Moving the
respective directional pedal will move the position
of the cam plate.
Moving the cam plate off center changes the
distance
the pistons travel inside the piston bore of rotating
assembly.The direction that the cam plate is rotated
from center determines the direction of fluid Flow
(forward or reverse).The number of degrees the cam
plate is deflected.determines how much fluid will
be displaced(speed)
The hydrostatic pump provides hydraulic fluid to the
hydrostatic motor through the back plate.Hydraulic
fluid in the power train circulates in a closed loop.
Fluid leaves the hydrostatic motor and is returned to
the hydrostatic pump,not the reservoir.Fluid that
leaves this closed loop circuit,such as case drain, is
replenished by fluid from the charge pump.
drives the input shaft for a three speed range gear
transmission which transfers power to the
wheels. (See Final Drive Section)
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