This invention relates innovative integration of Oil Pumps assembly with novel gasket to increase its reliability and durability on gas turbine engine.
Background of the invention
The typical existing Oil pump assembly is installed between the Pump casing and the Pump cover. As indicated in Figure 1 & 2, the oil pump assembly comprises a drive gear and driven gear installed in a pump body. The Oil pump casing comprises of a casing at the bottom of the pump, Pump casing, Pump cover, Two Intermediate plates installed between the pump casing and pump cover to which the fuel pump is attached.
There were a number of cases reported on oil pumps gas turbine engine for oil leaks from the body on the external surface. This is observed on oil pumps made in light alloys, having plate stack up configuration, which is observed leaks at the mating interface. The pump plates & casing are having metal to metal contact which requires high surface finish and controlled flatness on the surface. These pumps mostly leaks after few hours of service or after subsequent overhaul or when the pumps are disassemble from engine for change over. During such instance unknowingly the flatness of pump plates and casing gets disturbed and slight variation & irregularities developed on the surface, results in oil leakage from the mating interface. There are number of cases observed on gas turbine engine where such oil pump leakage resulted in grounding of aircraft by the operator. Many a time the repair agencies have to send the repair team for rectifying the snag by replacing with new oil pump.

Summary of invention
A novel method is introduced that comprises of the following features:
The innovative design methodology, includes a two number novel gasket introduced in pump assembly, one between the Pump casing and Pump plate and second between Pump plate and Pump cover. These gaskets are made of Klingersil material which is compatible with oils and can be introduced without disturbing the basic configuration of oil pump. Exhaustive static and dynamic analysis has been carried out to assess the integrity and dynamic characteristic of the pump under prevailing operating conditions. The basic design of the pump has been kept undisturbed, with no additional weight / mass penalty. Reliability of the gas turbine engine has been increased by controlling oil leakage from the oil pump.

Objective of invention
1. Main objective is to design and develop a novel method to avoid oil leak from the oil pump to increase the reliability of Oil pump on gas turbine engine.
2. To innovate novel modification on oil pump on improving the durability and life of oil pump.
3. To innovate simple solution, where basic design of the gas turbine engine is kept undisturbed, with no additional weight / mass penalty.
4. Enomious cost saving by salvaging the Oil pumps, which otherwise were rejected for minor irregularities or deviations.
Detailed Description of the invention
The innovative design methodology, integrates two numbers similar novel gaskets (refer Figure 3) in introduced in Oil pump assembly (refer Figure 4). One gasket integrated between Pump Cover & Intermediate Plate (refer Figure 5) and the other between Pump casing & Intermediate Pump plate (refer Figure 6). These novel gaskets are instaJled along with oil leak sealant. The novel gasket along with the sealant will completely seal the mating surface against minor scratches, dents, defonnation / distortion on plates & casing, if present Gaskets are made of Klingersil material which is compatible with oils and can be introduced without disturbing the basic design configuration of oil pump.

Analysis carried out
Detailed design and drawings of the novel gaskets and assembly drawing along with the novel gasket were generated using AutoCAD. Tolerance stack up analysis of Oil pump assembly with and without novel gasket carried out. Exhaustive static and dynamic analysis on the assembly has been carried out on test rig and on running gas turbine engine, under the prevailing conditions to assess the integrity and dynamic characteristic of the oil pump. The test rig performance and engine test performance of the Oil pump found satisfactory.

Claims:
We claim
1. Innovative integration of Oil Pumps assembly with novel gasket to increase its reliability and durability on gas turbine engine.
2. The method claimed in claim 1 has resulted in elimination of oil leakage from Oil pump assembly of gas turbine engine.
3. The method claimed in claim 1 has resulted in enormous saving in unit cost of oil pump assembly. This has been achieved by salvage / reuse of oil pumps, which otherwise were rejected for oil leaks and minor deviations.