3-5
1
1.5
1
2.5
<2.5
1
1
<1.5
0
Pump wheel
From the engine
T
R
T
P
= Torque of the pump wheel
T
T
= Torque of the turbine wheel
T
R
= Torque of the reaction member (stator)
T
T
Turbine wheel
To the gearbox
Reaction member
(stator)
Condition in the
coupling point
Intermediate
condition
Starting
condition
T
P
n
T
= 0.8n engine
n
T
< n engine
n
T
= 0
Machine standing
still
Function of a hydrodynamic torque converter (schematic view)
When the turbine speed is reaching about 80% of the pump speed, the torque multiplication becomes
1.0 i.e. the turbine torque becomes equal to that of the pump torque.
From this point on, the converter is working similar to a fluid clutch.
A stator freewheel serves to improve the efficiency in the upper driving range, in the torque
multiplication range it is backing-up the torque upon the housing, and is released in the clutch range.
In this way, the stator can rotate freely.
7577APT100
Summary of Contents for HL955
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