Torque Converter Fundamentals and Service Flashcards
What are the 2 major functions of a torque converter
Torque multiplication
Fluid coupling
Hydrostatics
Using fluids under pressure to achieve drive
Hydrodynamics
Energy transfer through fluid motion
Commonly called fluid couplings
Impeller
Also called pump
Is the drive portion of a TC
Turbine
Output element
In normal TC connected to output shaft
What 2 TC features help protect the driveline or trans
Shock absorption
Gradual start up of load
Vortex flow
When oil is flowing back and fourth between impeller and turbine
Turbine is spinning slower
Creates high torque
Called converter phase
Rotary flow
Occurs when oil flows same direction as impeller
Turbine and impeller spin about same speed
Lower torque
Called coupling phase
Split guide ring
Prevent turbulence and helps direct vortex flow
What are the 3 major components of a TC
Impeller
Turbine
Stator
TC stator
Changes the direction of the oil coming back from turbine so that instead of it slowing impeller it come into impeller with momentum
Stator can increase torque by how much
By a 2.00:1 to 3.00:1 ratio
What are the 2 styles of stators
Fixed
Freewheeling
Fixed type stator
Is attached to the converter housing stub shaft
Can never achieve rotary flow
Will be a single phase converter
Freewheeling stator
Has an overrunning clutch
Used in a 2 or more phase converter
Will lock up when turbine speed is less then speed of impeller
TC stage
Refers to the number of times oil strikes a set of turbine blades before returning to impeller
Stall speed
When greatest speed difference between impeller and turbine is created, generates highest torque multiplication
What are the functions of a torque divider
Provide automatic clutching
Multiply engine torque
absorb powertrain shock loads
What type of stator is used in a torque divider
fixed
Stall speed
Occurs when the turbine is stopped and the impeller is turning at rated engine speed (in TD turbine is going in reverse)
High stall speed
Occurs when there is not enough load on engine
- Slipping clutch
- Cavitation in converter`
Low stall speed
Engine speed is lower than specified
-Slipping stator
The purpose of the stator is
Change direction of oil flow
The purpose of the TC lock up clutch is
To increase efficiency
