rt flex mechanical

Wrtsil Land & Sea Academy Page 1 Chapter 20 19-Mar-08

RT-flex mechanical features

RT-flex Training

Mechanical Features (RT-flex Specific Parts only)

Chapter 20


RT-flex mechanical features RT-flex specific parts only


RT-flex mechanical features Overview, RT-flex50 (Size 0)

WECS-9520, E 95 Cylinder Electronic Unit Terminal boxes

Supply unit

Rail Unit(s)

Automatic filter

WECS-9520, E 90 Shipyard Interface Box (SIB) on the free end


RT-flex mechanical features Overview, RT-flex60C (Size 1)

WECS-9520, E 95 Cylinder Electronic Unit Terminal boxes

Supply unit

Rail Unit(s)

Automatic filter

WECS-9520, E 90 Shipyard Interface Box (SIB) on the free end


RT-flex mechanical features Overview, RT-flex84 and 96 (Size 4)

WECS-9520, E95 Cylinder Electronic Unit Terminal boxes

Supply unit

Rail Unit(s)

Control oilPumpsAutomatic filter

WECS-9520, E90 Shipyard Interface Box (SIB)or at the free end (smaller engines)


RT-flex mechanical features Rail Unit

For engines with more than 7 cylinders, the rail unit is split in two parts.

SIB (E90) Box on free end or in the middle of the rail unit depending on the number of cylinders (more than 7 cylinders in the middle)

WECS-9520 Cylinder-Electronic Unit boxes (E95) are fitted on the outer front side

Both rail-sections (forward/aft) for fuel-, servo- oil are cross connected by high pressure pipes. => Same pressure in the related rails of both halves.

Protection bars


RT-flex mechanical features Rail Unit, Size 0



RT-flex58T, MKI RT-flex58T, MKII


RT-flex mechanical featuresFuel oil rail

Servo oil rail

ICUs

VCUs

Control oil rail

Steam

Rail Unit Main Parts

Fuel oil rail:The fuel rail contains high pressure fuel of ~ 600 - 800 bar delivered by the fuel pumps of the supply unit.

For each cylinder, there is an Injection Control Unit (ICU). The rail is heated by a trace heating piping system.

Servo oil rail:The servo oil rail contains fine filtered (6-micron) high pressure servo oil, ~ 80 - 190 bar, delivered by the servo oil pumps of the supply unit, depending on engine load. For each cylinder there is a Valve Control Unit (VCU).

Control oil rail (some engine types only):The control oil rail contains 200 bar control oil (constant pressure) delivered by the control oil pumps.

Additional return/leakage piping: Fuel ICU-leakage pipe Common servo oil/control oil return pipe Main bearing oil pipe for exhaust valve actuator pipe (some engine types only)


RT-flex mechanical features (fuel) Injection Control Unit (ICU)

RT-flex96C


RT-flex mechanical features ICU, Size 0



Servo (control) oil side:The rail valves control the oil flow to the control oil block.

Fuel side:The fuel control valves are actuated by pistons in the control oil block. There is one valve for each injector.The main body of the ICU includes the injection quantity piston. Fuel Quantity Sensor in a housing kept away from the hot block.

Control- and fuel oil side are entirely separated from each other. Nevertheless, leakages of both systems have a common drain.

Working principle:Each ICU is pre-controlled by 2 or 3 rail valves to open or close the way for fuel from the rail to the injection nozzles.Fuel for each injection, necessary stroke is calculated and quantified, then injected, measured and corrected for the next injection.

Fuel quantity piston

Servo (control) oil side

Fuel side

Rail valves

Fuel control valves

Fuel quantity sensor

Servo oil supply

Servo oil return

ICU


RT-flex mechanical features Fuel Nozzle

Fuel nozzle with venting spiral(not valid for MKI)

Opening pressure 375 bar


RT-flex mechanical features (exhaust) Valve Control Unit (VCU)

Valid for flex 50B, 58T (MKII), 60C (MKII), 68B, 84T-D


RT-flex mechanical features VCU

Valid for flex 58T (MKI), 60C (MKI), 96C-B



The servo oil supply from the servo oil rail to the 3/2 way valve is done via connecting element. The 3/2 way valve is pre-controlled by a rail valve (same type as for ICU).

The servo oil return pipe has a back pressure of ~2-3 bar to dampen pressure peaks.

To the upper part of the VCU/actuator pipe, there is a main bearing oil inlet via a non-return valve, in order to fill up the oil losses through the orifice in the exhaust valve drive.

Main bearing oilsupply

Servo oil return

Connecting element

Rail valve

To exhaust valve3/2 way valve

VCU cylinder and piston

VCU (MKI, 96C-B)

Shown for flex 58T (MKI), 60C (MKI), 96C-B


RT-flex mechanical features VCU (50B, MKII, 68B, 84T-D)Rail Valve

3/2 way valve

VCU piston

Servo oil supply

To exhaust valve drive

Servo oil return

HP-hoses to/from ICU

The VCU sits directly on the servo rail.

In order to refill the intended oil loss through the constant orifice in the exhaust valve drive upper housing, there is an internal orifice to the upper part of the VCU/actuator pipe.

Valid for flex 50B, 58T (MKII), 60C (MKII), 68B, 84T-D


RT-flex mechanical features Rail Unit Piping

Shown for RT-flex96C-B



Shown for RT-flex96C-B


RT-flex mechanical features Rail Unit Piping, Size 0

Trace heating

Servo oil rail

Fuel oil rail

ICU

VCU

Fuel overpressure regulating valve

Servo oil return pipe



Trace heating

Servo oil rail

Fuel oil rail

ICU

VCU



RT-flex mechanical features Rail Unit Piping, Size 1 MKIFuel rail:The fuel rail contains high pressure fuel of ~ 600 -900 bar delivered by the fuel pumps of the supply unit during engine operation. The rail pressure is regulated depending on engine load. For each cylinder, there is an Injection Control Unit (ICU) installed on the fuel rail. The ICUs are actuated by help of control oil pressure. WECS is activating the ICUs for injection control. The rail is heated by a trace heating piping system.

Servo oil rail:The servo oil rail contains fine filtered (6-micron) high pressure servo oil, ~ 80-190 bar, delivered by the servo oil pumps of the supply unit, depending on engine load. For each cylinder there is a Valve Control Unit / exhaust valve actuator (VCU) installed on the servo oil rail. WECS is activating the VCUs for exhaust valve control.

ICUsVCUs


Main bearing oil supply

Control oil supply rail

Control oil return rail

Fuel rail

Servo oil rail


RT-flex mechanical features Rail Unit Piping, Size 1 MKI

Additional piping in previous design:

ICU fuel drain pipe. (constant orifice leakage drained to fuel return to booster unit)

Fuel leakage drain (ICU internal leakage or injection pipe leakage)

Control oil supply rail to supply actuating control oil to ICUs.

Separate control oil return rail.

Main bearing oil supply to VCU (refilling of drained oil through constant orifice in exhaust valve drive)

Fuel leakage drain to overflow tank

ICU fuel drain pipe

Trace heating


RT-flex mechanical features Rail Unit Piping, Size 1 MKI

Control oil pumps:- Two electrically driven control oil pumps supply control oil with constant pressure of 200Bar to the control oil supply rail.

Overpressure regulating valve:- Similar function as the valve used for new design, but the SHD function is not included. (fuel drained to overflow tank)

SHD-valve arrangement:- The SHD solenoid valve (energised by Safety System) enables control air to the SHD-servo, that activates the SHD-valve itself to depressurize the fuel system. (fuel drained to overflow tank)

Control oil pumps

Overpressure regulating valve

SHD-valve arrangement

Control oil supply rail

Control oil return rail


RT-flex mechanical features Rail Unit Piping, Size 1 MKIIFuel oil rail:The fuel rail contains high pressure fuel of ~ 600 -900 bar delivered by the fuel pumps of the supply unit during engine operation. The rail pressure is regulated depending on engine load. For each cylinder, there is an Injection Control Unit (ICU) installed on the fuel rail. The ICUs are actuated by help of servo oil pressure via hydraulic HP-hoses. WECS is activating the ICUs for injection control.The rail is heated by a trace heating piping system. Fuel rail

Servo oil rail

ICUs

VCUs

Servo oil rail:The servo oil rail contains fine filtered (6- micron) high pressure servo oil, ~ 80-190 bar, delivered by the servo oil pumps of the supply unit, depending on engine load. For each cylinder there is a Valve Control Unit / exhaust valve actuator installed on the servo oil rail. WECS is activating the VCUs for exhaust valve control.

The high pressure rails of new design are made of single pipes. The ones of old design rail of rail pipe sections.


RT-flex mechanical features Rail Unit Piping, Size 1 MKII

Additional return/leakage piping:

One fuel leakage pipe (back to overflow tank)One common servo oil return pipe

(back to crankcase)Trace heating (steam or thermo oil)

Fuel system overpressure valves:

SHD and overpressure regulating valve. Opening pressure approx. 1050bar for overpressure regulation. The SHD-solenoid is activated by Safety System to depressurize the fuel system (fuel drained to return pipe to booster unit).

Safety valve. Opening pressure 1250bar. (fuel drained to overflow tank).

Safety valve

SHD and overpressureregulating valve

Fuel leakage pipe

Trace heating




ICU and injection high pressure pipe leakage drain pipe (connected to leakage collector => Alarm to AMS)

Control oil rail

Main bearing oil supply pipe forupper side of VCU (flex96C-B only)

Control oil high pressure hoses

Servo oil (and control oil) common return pipe

Servo oil rail

Trace heating

Fuel oil rail



At each inlet, there are shut-off valves, in order to isolate individual HP-pipes in case of leakages.

Fuel-, servo- and control oil inlet to the rails are between the two rail unit halves (if more than 7 cylinders).

For redundancy reasons there are for each system two rising pipes connected to the two rail unit halves.

The cross-connection high pressure pipes enable a direct connection between each rail forpressure equalization if one HP pipe is broken, it can be shut-off on

both ends and the remaining one feeds both rails



Rail unit general drain piping. Possible leaks of fuel, oil and water are collected for each rail => Alarm to Alarm System Rail Unit (FWD), General Leak. The leakage is drained to the sludge tank.

Rail Unit Piping


RT-flex mechanical features Fuel Rail Pipe

The fuel rail pipe is made of one piece.

The bore has a shape of a peanut.

Shown for RT-flex96C


RT-flex mechanical features Rail Valves



Rail valve are quick acting 3/2-way solenoid valves. Each cylinder unit has four rail valves. Three of them are pre-controlling an ICU, one of them is pre-controlling the VCU. Flex50 has only two rail valves per ICU.

Following an injection/return- or open/close command of WECS-9520, the corresponding coils are energized for a very short time (normal operation ~1 ms, max. 4.5 ms), but with a high current impulse (~50-60A). This makes the valve spindle move towards the energized coil (~0.3 mm stroke).

The high current impulse and the short travel of the valve spindle enable a very short actuation time, which is indispensable for precise injection- or exhaust valve control.

The rail valves are non-serviceable. Nevertheless, if dirt particles are suspected to influence proper operation, the valves can be opened and blown out by air.

Pay attention to the assembly position of valve spindle.

Rail Valve RV-2

Valve spindle

Coils

Iron core

Control oil inletInlet/outlet to ICU/VCU

Outlet to return pipe

Electric sockets

Injection / Valve open

No injection / Valve close


RT-flex mechanical features Exhaust Valve Drive (50-B, MKI)



Main differences to a conventional RTA-valve drive:

The exhaust valve is actuated by a double piston drive, in order to save oil volume

Two redundant exhaust valve stroke sensors for monitoring

One measuring cone for stroke sensors Air spring piston runs directly in the

housing.

The disc spring package is dampening opening stroke in case of low air spring pressure

Exhaust Valve Drive (60C)

Exhaust valve spindle

Air spring piston

Measuring cone

Double pistondrive

Damper

Disc spring package

Two exhaust valve stroke sensors

Oil inlet fromexhaust valveactuator pipe

Orifice

Joint ring


RT-flex mechanical features Exhaust Valve Drive (58T-B, MKI)


RT-flex mechanical features Exhaust Valve Drive (60C, MKI)



Main differences to a conventional RTA-valve drive:

The exhaust valve is actuated by a double piston drive, in order to save oil volume

Two redundant exhaust valve stroke sensors for monitoring

One measuring cone for stroke sensors Air spring piston runs directly in the

housing.

The disc spring package is dampening opening stroke in case of low air spring pressure

Exhaust Valve Drive (96C)


Air spring piston

Measuring cone

Double pistondrive

Damper

Disc spring package



Orifice

Joint ring


RT-flex mechanical features Exhaust Valve Drive (96C)


Air spring piston

Measuring cone

Double pistondrive

Damper

Disc spring package



Orifice

Thrust piece


RT-flex mechanical features Supply Unit Drive, Size 0

Single lobe drive



RT-flex58T-B RT-flex60C



The supply unit is driven by the crankshaft, via two intermediate gearwheels.

3-lobe cams are mounted to the camshaft (size 0 with single lobe mono block camshaft and size 3 with 2-lobe mono block camshaft).

The servo oil pumps are driven by individual pinions, having a mechanical fuse (reduced diameter in pinion), in order to protect the gear- drive in case of a pump seizure. The servo oil pump gearwheel is hydraulically fitted as well.

Since the supply unit, i.e. fuel pumps and servo oil pumps have no timing, means they just supply fuel or oil, the camshaft doesnt have to have a determined position compared to crankshaft. However the position of the cams relative to each other must be respected.

3-lobe cams Supply unit gearwheel

Servo oil pump drive gearwheeland pinions2nd intermediate

gearwheel

Camshaft bearingcovers

Supply Unit Drive

Drawn for Size 4


RT-flex mechanical features Supply Unit, Size 0



RT-flex60

RT-flex58T



Fuel side: The jerk-type fuel oil pumps deliver fuel into the intermediate accumulator. To keep the rail pressure (600 - 900 bar), the pump flow rate is regulated via regulating linkage and el. actuators, by pressure set point signals from WECS.

From the accumulator there are two outlets, connecting the accumulator to the fuel rail via two rising pipes.

Servo oil side: The servo oil pumps are made by Dynex or Bosch. They deliver servo oil into servo oil collector block with a pressure of ~ 80 -190 bar. There are two outlets from the collector block, connecting to the servo oil rail via two rising pipes.

The number of fuel- and servo oil pumps depends on the number of cylinders.

Fuel pumps

Servo oil pumps (shown here as Bosch)

Fuel intermediate accumulator

Servo oil collector block

Servo oiloutlet to rail

Fuel outlet to rail

2nd intermediate gearwheel

Electric actuators

Supply Unit


RT-flex mechanical features Supply Unit, size 4

Shutdown & overpressure regulating valve

Fuel drain

Fuel return to mixing tank

Shutdown solenoid valve

Fuel pressure retaining valve

Fuel inlet from booster unit

Intermediate accumulator withtwo safety valves (1250 bar).


RT-flex mechanical features Fuel Pump



Fuel pumps:

The jerk-type fuel pumps deliver a variable quantity of fuel to the intermediate accumulator and fuel rail, in order to maintain the demanded rail pressure. They do not have any timing. To change the feed quantity, the pump plunger is turned by the regulating rack.

The roller guide/roller assembly and regulating sleeve are lubricated by main bearing oil via a double orifice.

Fuel Pump

Regulating rack

Buffer space

Non return valve

Pump plunger

Pump cylinder

Compression spring

Roller guide

Lower housing

Upper housing

Pump cover

Regulating sleeve

Roller


RT-flex mechanical features Fuel Pump



Plunger position at regulating linkage position:

Pos: 0No delivery

Pos: 5Half delivery

Pos: 10Full delivery

Fuel Pump



Fuel pump regulating linkage:

The regulating linkage is moved by Woodward (ProAct IV) electric actuators. They receive a position set point signal from WECS. One actuator controls two fuel pumps (the arrangement of actuators can differ among engine cylinder numbers).

The torque from linkage shaft to fork lever is transmitted in both directions via torsional springs. If a regulating rack of a pump is stuck for some reason, the springs will compensate, so the other pump can still be regulated.

Electric fuel pump actuators

Local position indication (0-10).

No load indicator !!Torsional springs

Fork lever

Regulating Linkage

Additional spring to push the rack, in case of failure, to full position



Servo oil pumps arrangement:The servo oil pumps supply oil to the collector block, which has two high pressure outlet pipes to the servo oil rail. A safety valve limits the max. pressure to 230 bar.The number of servo oil pumps depends on the number of cylinders. If one pump fails, the engine can still be operated.

Supply Unit, Servo Oil (96C)

Dynex pumps arrangementBosch pumps arrangement (some engines only).

Collector Block

Oil supply

Non return valves at each inlet

Safety valve

High pressure pipes

Servo oil pumps

Flow sensor


RT-flex mechanical features Servo Oil Pump Dynex

Compensator valve with solenoid

HP-outlet (Inch-type thread!)

Suction port


RT-flex mechanical features Servo Oil Pump Dynex


RT-flex mechanical features Servo Oil Pump Bosch, flex96C-B

The Bosch servo oil pumps are axial piston swashplate type pumps. They supply oil to the collector block and via two high pressure pipes to the servo oil rail. A safety valve limits the max. pressure to 230 bar.The number of servo oil pumps depends on the number of cylinders. If one pump fails, the engine can still be operated at full load.When the engine turning direction is reversed, the swash-plate of the pumps needs to be reversed as well. Control oil is used to move the swash-plate to position.


RT-flex mechanical features Servo Oil Pump Bosch

Swashplate angle encoder

Proportional valve positiontransmitter

Proportional valve solenoid-valves

High pressure outlet

Anti cavitationinlet (from servo oil mainsupply pipe)

Non return Valve / anticavitation port

Control oil inlet Leak oil returnCase drain

Main oil inlet

Proportionalvalve

HP-outlet pressuretransmitter

Visual indication


RT-flex mechanical features Servo Oil Pump Bosch

The Bosch-Rexroth pumps have its own regulating system, getting pressure setpoint signals and ahead/astern signals from WECS.The anti-cavitation port avoids cavitation in the pump body, if a pump does not move the swashplate to the appropriate engine running direction. (pump tries to suck in from HP-outlet pipe).

In such a case, the non-return valve at anti-cavitation port opens. Servo oil from main supply pipe is sucked in via anti- cavitation port and delivered out again via main inlet. The oil will thus flow "idle" through the pump.

This is default in case of black out, the swashplate swings to ASTERN position to prevent servo oil overpressure due to windmilling engine without servo oil consumption.

B,B1 Pressure Port SAE 1 1/2 "SB Anti Cavitation Port SAE 2 "S Suction Port SAE 3 "P,SP Control Pressure Port M18x1.5Rkv Pilot Fluid Drain M22x1.5R(L) Return (Aeration) M42x2


RT-flex mechanical features Control Oil Pumps (Size 1, MKI)

RT-flex58T, MK1



2 Pressure retaining valves2 Overpressure relief valves

Control Oil Pumps, Size 4

HP-Inlets from pumps

2 (3) HP-outlets for double wall pipes -> control oil rails

3 shut of valves for outlets

Pressure transmitterfor leak detection (signal to Alarm System)

Drain valve for leakage (with orifice)

Kraus & Wimmer

Bucher


RT-flex mechanical features Service Pump


RT-flex mechanical features Automatic Filter

The automatic filter unit filters the servo (and control-) oil to 6 m. The by-pass filter has a mesh size of 36 m. The filter "sludge" goes back to the crankcase.


RT-flex mechanical features Crank Angle Sensor (CA)

The crank angle signal is absolutely indispensable for engine operation.

At least one of the sensors must be working. If one fails, WECS-9520 can detect the failure and will keep working with the healthy signal (plausibility check). In case both sensors fail, the engine will stop without delay.

There is no emergency operation possible without at least one CA sensor!

The crank angle sensors are located on the free end of the crankshaft (or Geislinger Damper).



CA-Sensor, complete with holder and cable.

CA-Sensor

They are separated from the crankshaft by a special coupling. They create an exact digital signal of the actual crankshaft position (0.360) The CA sensors have a resolution of 0.1

The spring loaded coupling absorbs all longitudinal and axial movement of the crankshaft. It drives a shaft which is supported by two ball bearings. The bearings are oil lubricated. From the shaft a toothed belt drives each sensor.

Shielded BUS cables transmit the signals to the WECS-9520 control.

CA-Sensors are delivered in a box


RT-flex mechanical features CA-Sensor


RT-flex mechanical features CA-Sensor

Connection unit CA Sensors

RT-flex TrainingRT-flex specific parts onlyOverview, RT-flex50 (Size 0)Overview, RT-flex60C (Size 1)Overview, RT-flex84 and 96 (Size 4)Rail UnitRail Unit, Size 0Rail Unit, Size 1Rail Unit, Size 2Rail Unit, Size 4Rail Unit Main Parts(fuel) Injection Control Unit (ICU)ICU, Size 0ICU, Size 1ICU, Size 2ICU, Size 4ICUFuel Nozzle(exhaust) Valve Control Unit (VCU)VCUVCU (MKI, 96C-B)VCU (50B, MKII, 68B, 84T-D)Rail Unit PipingRail Unit PipingRail Unit Piping, Size 0Rail Unit Piping, Size 0Rail Unit Piping, Size 1 MKIRail Unit Piping, Size 1 MKIRail Unit Piping, Size 1 MKIRail Unit Piping, Size 1 MKIIRail Unit Piping, Size 1 MKIIRail Unit Piping, Size 4Rail Unit PipingRail Unit PipingFuel Rail PipeRail ValvesRail Valve RV-2Exhaust Valve Drive (50-B, MKI)Exhaust Valve Drive (60C)Exhaust Valve Drive (58T-B, MKI)Exhaust Valve Drive (60C, MKI)Exhaust Valve Drive (96C)Exhaust Valve Drive (96C)Supply Unit Drive, Size 0Supply Unit Drive, Size 1Supply Unit Drive, Size 2Supply Unit Drive, Size 3Supply Unit Drive, Size 4Supply Unit DriveSupply Unit, Size 0Supply Unit, Size 1Supply Unit, Size 2Supply Unit, Size 3Supply Unit, Size 4Supply UnitSupply Unit, size 4Fuel PumpFuel PumpFuel PumpFuel PumpRegulating LinkageSupply Unit, Servo Oil (96C)Servo Oil Pump DynexServo Oil Pump DynexServo Oil Pump Bosch, flex96C-BServo Oil Pump BoschServo Oil Pump BoschControl Oil Pumps (Size 1, MKI)Control Oil Pumps, Size 4Service PumpAutomatic FilterCrank Angle Sensor (CA)CA-SensorCA-SensorCA-Sensor

rt flex mechanical

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