TSE DPT60, Owner'S Manual

Page: 236 / 459

7
Series 90 Functional Description
Basic Closed Circuit
90000803E
The Basic Closed Circuit
The main ports of the pump are connected by hydraulic
lines to the main ports of the motor. Fluid flows, in either
direction, from the pump to the motor then back to the
pump in this closed circuit. Either of the hydraulic lines
can be under high pressure. In pumping mode the
position of the pump swashplate determines which line is
high pressure as well as the direction of fluid flow.
Case Drain and Heat Exchanger
The pump and motor require case drain lines to remove
hot fluid from the system. The motor should be drained
from its topmost drain port to ensure the case remains full
of fluid. The motor case drain can then be connected to
the lower drain port on the pump housing and out the top
most port. A heat exchanger, with a bypass valve, is
required to cool the case drain fluid before it returns to the
reservoir.
Circuit Diagram for Series 90 PV and 90 MF
90000800E
The System Circuit
Control Handle Displacement Control Valve
Orificed
Check Valve
Heat Exchanger
Bypass Valve
Heat Exchanger
Reservoir
Vacuum Gauge
Multi-Function Valve
Servo Control
Cylinder
Pump Swashplate
Motor Swashplate
Input
Shaft
Output Shaft
to Pump
Case
Charge Pump
Servo Pres.
Relief Valve
Multi-Function
Valve
Charge Pressure
Relief Valve
Fixed Displacement
Motor
Servo Control
Cylinder
Variable
Displacement
Pump
Case drain fluid
System loop
(high pressure)
System loop
(low pressure)
Loop Flushing Valve
Purge Relief Valve
Control fluid
Suction line
Pump Fixed Motor
Input
PV
MF
Case Drain Line
Output
Flow (Bi-directional)
Reservoir