Following specifications describe the nature of invention and performance of the machine compared to the old machine.

This invention relates to lapping of blades in the respective slot of the turbine disc of Orpheus engines to improve the load sharing by the root lobes

Background of invention:

Failure of the turbine blades normally occur due to top serration loading, it can be avoided by introducing lapping which ensure that all serrations touch and share the load under the engine running conditions.. On production and overhaul engines, all new blade fitted with new discs are to be lapped in their respective disc slots. There are 120 slots in the turbine disc. In old lapping machine, lapping is carried by mounting disc in lapping machine and taking one blade , from respective turbine slot and lap the blade root to the disc by pushing the blade into and out slot 150 times by kinematics motion. This process of lapping blade is time consuming as it is possible to load only one blade at a time. Due to this, the production and overhaul rates of the engines are severely affected and the customers' demands are not met.

Summary of Invention:

A new design system introduced comprises of the following features: A pneumatic cylinder replaces the old kinematic motion thus providing a compact, robust, silent, non-hazardous, environment friendly green machine. Three major parts in the new design system includes a bottom plate, an intermediate plate & a top plate clamped together with pillars. The bottom plate is round plate which supports the whole system & can be mounted on bench table. The intermediate plate is a housing for 25 numbers of pneumatic cylinder which operates through pneumatic power pack and indexer plate for indexing slots is mounted in this intermediate plate. Lapping operation can be carried out by mounting the work piece (Turbine disc) on top plate. This new design system reduces the lapping time and thus reduces the cost of manufacturing & assembly of the Orpheus engines.'

Objectives of the Invention:

1. To achieve required surface finish parameters as per specification to improve load sharing by the root lobes.

2. To reduce lapping time & assembly time.

3. To make the machine compact and user friendly. Detailed description of invention: Detailed new design system is illustrated in fig-1 and fig-2. Figure-1 represents the general arrangement of new design system with bill of material listed and figure-2 shows a sectional view of new design system.The main part, the bottom plate supports the entire system along with components turbine disc & blade located accurately with the help of pillars that are holding entire setup rigidly and preventing any sort of vibration during lapping operation. The intermediate plate is accommodating a pneumatic cylinder and indexing arrangement, with a locating adaptor to rotate, clamp and align precisely and with the locking arrangement, the whole setup can lock & unlock after each indexing. Another part, the top plate supports & clamps the turbine disc rigidly and prevents any movement during the lapping operation. The indexing plate along with other various detail parts is meant for indexing 125 slots and to align turbine disc slots in line with turbine blades that are held in blade holder and are connected to pneumatic cylinder with help of link arrangement. 25 nos. of double acting pneumatic cylinders are provisioned in intermediate plate to actuate at a time with 5 times indexing. Pneumatic cylinder is actuated through pneumatic power pack. The lapping system is designed to complete the process of lapping a total of. 125 slots of turbine with blades. Parts were manufactured as per the detail part drawings generated and integrated with all other special & standard bought-out items. Actuation test was carried out by supplying required compressed air at 6 bar pressure to the double acting cylinder through pneumatic power pack and found that the required surface parameters are achieved as per specification. The new invention reduces the lapping time by 75% as compared to the old kinematics motion machine and thus improves the production rate and helps in meeting the customer needs of quality and delivery.

Claims:

1. A novel design system to achieve required surface finish parameters as per ■ specification to improve the load sharing by the root lobes.
2. The method claimed in claim 1 has resulted in making user friendly & compact machines
3. The method claimed in claim 1 has reduced cost of manufacturing and assembly