A leading gas turbine engine manufacturer embarked on a
complete redesign of the lubrication system for one of their most successful aero-derivative engines. One primary objective of the project was to move the lube system from a large external skid to inside the smaller engine enclosure. Also critical to this new skid design was to standardize the electrical and mechanical devices which meet new international design protocols, to increase overall reliability by reducing component count, and to significantly reduce production costs.
After reviewing a variety of oil pump manufacturer’s catalogs for an off-the-shelf solution, this manufacturer chose to work with Cascon to develop a custom lube and scavage pump that would achieve all of their goals. Every component would be catered to the success of the final product.
The redesigned lubrication system now features Cascon’s two integrated multi-circuit gerotor pumps, which met all the program objectives for space and cost reductions while providing measureable improvements in system reliability. The fully integrated pumps were engineered from the ground up with an eye toward system optimization at every level. Actual production costs would remain within budget constraints. Cascon provided design and manufacturing services to support all phases of the project including prototype development, product qualification, and ramp-up to serial production.
- The duplex arrangement of electric motor driven lube oil pumps ensures availability at all times; one pump is in operation at all times while the other pump stands by as backup.
- Each pump assembly provides five independent pumping functions; oil supply for gas generator lubrication, high pressure oil for variable inlet guide vane actuation, and independent scavenge of three engine bearing compartments.
- Pressure relief valves for the lube supply and hydraulic control circuits are easily accessible from the top port plate to perform routine calibration checks. These valves are integrated directly into the pump housings.
- Internal flow paths within the ductile cast iron pump housings route oil from the individual pump circuits to the port plate located outside the reservoir.
- The port plate provides structural support for the pump and drive motor, with mounting holes and a pilot diameter for the motor adaptor, a machined bore to contain the field replaceable shaft seal assembly, and a series of SAE straight thread o-ring ports for interconnect to each of the individual pump circuits.
The resulting aero-derivative GT (gas turbine) package, combined with power turbines, compressors and related ancillary equipment, is available for both mechanical drive applications and electric power generation. It is capable of delivering up to 40,000 shaft HP or 32 MW base load electrical output, and is considered to be the world’s most successful gas turbine package serving the oil and gas industry today.
Select Performance Data:
Fluid: Synthetic ester based oils
Lube Circuit Flow: 33 GPM @ 240 psid
Front Bearing Scavenge: 5 GPM @ 20 psid
Center Bearing Scavenge: 22 GPM @ 20 psid
Rear Bearing Scavenge: 22 GPM @ 20 psid
VIGV Circuit: 9 GPM @ 500 psid
Ambient Temp Range: -45 degF to +250 degF
Operating Speed: 3600 rpm
Lube Relief Valve: Integral – 350 psid crack
VIGV Relief Valve: Integral – 1000 psid crack
MTBO: 20,000 hours