TSE PTV100/72, Owner'S Manual, Page: 266 / 480

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Series 90 Functional Description 2
Piston
Roller Bearing
Control Piston
Input Shaft
Valve Plate
Cylinder Block
Cradle Swashplate
Manual Displacement Control
Charge Pump
2. Functional Description
This section describes the operation of pumps, motors, and their various serviceable features. It is a useful
reference for readers unfamiliar with the functioning of a specific system.
2.1 General Description and Cross Sectional Views
90000189
Series 90 Variable Displacement Pump (PV)
Series 90 Fixed Displacement Motor (MF)
90000347
90000346
Series 90 PV Cross Section
2.1.1 Variable Displacement Pumps
The Variable Displacement Pump (PV) is designed to
convert an input torque into hydraulic power. The
input shaft turns the pump cylinder which contains a
ring of pistons. The pistons run against a tilted plate,
called the swashplate. This causes the pistons to
compress the hydraulic fluid which imparts the input
energy into the hydraulic fluid. The high pressure fluid
is then ported out to provide power to a remote
function.
The swashplate angle can be varied by the control
piston. Altering the swashplate angle varies the dis-
placement of fluid in a given revolution of the input
shaft. A larger angle causes greater displacement
which yields greater output torque for a given input. A
smaller angle reduces the displacement per revolu-
tion and yields greater speed for a given input.
2.1.2 Fixed Displacement Motor
The Fixed Displacement Motor (MF) is designed to
convert an input of hydraulic power into an output
torque. It operates in the reverse manner of the
pump. The high pressure hydraulic fluid enters through
the input port. The fluid pressure builds behind the
pistons causing them to move down the swashplate
(the path of least resistance). As the piston returns up
the swashplate again, the fluid is allowed to exit
through the exit port. The spinning pistons are housed
in a cylinder which is connected to the output shaft.
The output torque can be applied to a mechanical
function.
CONTENTS