TORQUE CONVERTER OPERATION

Presented By

Prem Baboo

Sr. Manager(Prod)

Plant’s & Equipment's Designer

National fertilizers Ltd. India,

An Experts for www.ureaknowhow.com

Fellow of Institution of Engineers, India

VOITH TORQUE CONVERTER

The hydrodynamic torque converter is provided for step less speed/torquetransmission.

TURBINE WHEEL

ADJUSTABKE GUIDE BLADES

PUMP IMPELLER

INPUT AND OUT PUT SHAFT

ADJUSTMENT MECHANISM

The heart of Voith’s hydrodynamic torque converter is its hydraulic circuit;consisting of a pump, turbine, and a guide wheel with adjustable guidevanes (see picture above right). This is combined in a common housingfilled with hydraulic oil. The mechanical energy of the motor is convertedinto hydraulic energy through the pump wheel. In the turbine wheel thesame hydraulic energy is converted back into mechanical energy andtransmitted to the gas turbine / generator shaft. The

CONSTRUCTION DETAIL

adjustable vanes of the guide wheel

regulate the mass flow in the circuit. At

closed guide vanes (small mass flow) the

power transmission is at its minimum.

With the guide vanes completely open

(large mass flow), the power

transmission is at its max imum.

Commonly, a constant speed driver such

as an induction motor or a diesel engine

drives the pump wheel (input shaft of the

torque converter)

Because of the change in mass flow (due

to the adjustable guide vanes) the

turbine wheels’ speed is variable and can

be adjusted to match the various

operating points of the turbine. At low

speed, the turbine develops its highest

torque. With increasing turbine speed,

output torque decreases

The input shaft is connected with the pump

impeller. The output shaft is connected with the

turbine wheel. Both converter shaft are supported

by antifriction bearings. The input shafts are sealed

using shaft seal rings. The guide vane adjustable

mechanism is actuated via the control piston. In

this position, two servo pistons follow(hydraulic

follower control). The servo pistons are moved by

pressure oil supplied by the gear pump and

adjustable of the blades is made by the two piston

rods via the fork, the regulation ring and adjustable

leaver. By this control combination, the guide vanes

are moved to 0% or 100 % guide vane position

department on the converter operating state.

The pump impeller, the guide wheel and the

turbine wheel form the oil-filled circuit together

with the converter shell.

A gear pump is installed in the torque converter

which is driven directly and connected with the

input shaft.

The housing of torque converter supports the

internal parts controlling the oil supply and oil

discharge.

In addition the converter housing is used as oil

tank.

OPERATION- TORQUE CONVERTER

The hydrodynamic torque converter is provided for

steeples speed/torque transmission (multiplication)

between motor & driven machine. The pump impeller

absorbs the mechanical energy of driving machine(motor)

with the 3rd power of input speed(n3). The turbine wheel

converts the kinetic energy existing in the fluid mass back

to mechanical energy. The guide wheel absorb the

differential torque between pump impeller and turbine

wheel which results in a torque multiplication. The guide

vanes of the second guide wheel are adjustable and effect a

change of the flow direction. The inside diameter between

the guide vanes, relative to the value in the design point, is

provided as "relative guide vane position”(in %) to

describe the operating behavior.

Dependent on the guide vane position between 0%

and 100 %, a corresponding torque is transmitted

via the turbine wheel as a function of the output

speed. the pump impeller and the turbine wheel

rotate in the same direction. There is no mechanical

connection between the pump impeller, turbine

wheel and guide wheel. Torque transmission is load

independent, i.e. the torque produced in the turbine

wheel has its max. point during standstill of the

output shaft since reversal of fluid is maximum here,

and decreases with increasing speed. Thus the

torque converter adapts sleeplessly and

automatically to the resistance occurring

OIL CIRCUITThe housing is provided as oil tank The same oil is used as

working oil, control oil, lube oil and cooling oil. The torque

converter is supplied with working oil by gear pump

installed inside.WORKING OIL CIRCUIT

The gear pump supplies the working oil directly into the

working chamber of the torque converter. For heat

dissipation, a certain quantity of working oil flows from

the closed circuit of the working chamber through the

working oil orifice plate , the heat exchanger and the

bypass oil filter back to the torque converter. The

converter pressure in the flow to the working oil outlet

must be approx. 5 bar. The converter pressure is

determined as a function of working oil orifice plate bore.

CONTROL OIL

A gear pump pinion supplies the adjustment

mechanism with control oil. The oil pressure of this

circuit is provided by a pressure relief valve. The

control oil pressure is limited to 15 bar via the

pressure relief valve.

LUBE OIL CIRCUIT

All antifriction bearings are surrounded by the

torque converter working oil. A separate

lubrication of the bearings is not necessary

during operation of the converter.

GUIDE VANE ADJUSTMENT

The guide vane adjustment enables a continuous change of the

power transmission. This means that a speed adaptation is possible

for any drive of driven machine whereas the load dependency

remains unchanged.

PNEUMATIC LEVER ACTUATOR

The pneumatic actuator with lever acts on the servo piston via the

control piston. The control piston moves in the piston rod which

runs in the mechanically connected with the regulating ring. The

guide vanes are adjusted with existing control oil pressure. A pinion

on the gear pump supplies the servo unit with control oil through the

ducts in the control piston and the position of the piston rod to the

corresponding cylinder. The two servo cylinders are connected by oil

ducts in the housing. The control piston adjust the position of the

vanes guide wheel via the regulating ring until the servo piston is no

longer supplied with oil due to the position of the piston rod .

DESCRIPTION FREQUENCY OF

MAINTENANCE

Crankcase Inspection Two Year

MPI of Crankshaft / Connecting Rod Two Year

Main Bearing Replacement 40000 hrs.

Tandem Valves & it’s ‘O’ Rings Replacement3000 hrs.

Torque Convertor Inspection Two year

Valve Block Inspection 3000 hrs

Gear Box High Speed Shaft Seal Inboard Two Year

Torque Converter Shaft Seal OutboardTwo Year

GUIDE VANES

INTERNAL GEAR PUMPS ATTACHED WITH

INPUT SHAFT

OUTPUT SHAFT

THANKING YOU

For any types of queries please write me

pbaboo@hotmail.com

Prem.baboo@nfl.co.in

Mob- +919425735974