Patent GB-840506-A (GB)
Title: Improvements in or relating to testing apparatus, for example, for testing turbine and compressor rotor discs
Inventor: POPE JOSEPH ALBERT
IPC: F01D5/02
Filed: 1957-03-04
Abstract: 840,506. Testing physical qualities of materials. ROLLS-ROYCE Ltd., and POPE, J. A. March 3, 1958 [March 4, 1957], No. 7180/57. Class 106 (2). [Also in Group XXVI] A testing apparatus in which rotor discs such as blade-carrying discs of turbines or compressors may be subjected to loads simulating loads experienced in use, comprises an annular frame, means connectible to the rotor disc at its centre to support the disc coaxially within the frame, a plurality of fluid-pressure-operated rams mounted on the frame at angularlyspaced positions, connector elements which extend inwards from the frame towards the rotor disc, are connected to the rams to be moved radially of the annular frame and are adapted for connection to the rotor disc periphery at selected angularly-spaced points thereon, and means supplying pressure fluid to the rams to apply through the connector elements predetermined loads at said selected points on the disc. The apparatus shown comprises a pair of annular plates 10 which are interconnected by means of a number of circumferentially-spaced bridge pieces 11 which are secured to the plates by screws 11c. The lower plate 10 is secured by means of screws 16 to a back plate 13 which is formed with a hollow boss 14 to receive a bush bearing 15. A hub member 17 is mounted in the bearing 15 and is provided with external splines 18 which engage with the splines formed at the centre of the rotor disc 12 to be tested. A torsion bar 19 is secured to the hub portion 17 by means of dowel pins 20 and screws 21, the position of the torsion bar in relation to the plates 10 of the frame being adjusted by means of screws 22 mounted in brackets 23 which are secured to the upper plate 10. The position of the torsion bar is indicated by pointers 25 moving over scales 24. A pair of hydraulic rams 26 is associated with each bridge piece 11, the rams each comprising a cylinder 26a and piston 29. One end of the cylinder 26a is of spherical form 26b and is received in a recess 27 in the bridge piece 11, the cylinder being retained in position in the recess by means of a retainer 27a. The pistons 29 of each pair of rams bear against a crosshead 30 which is pivotally connected at its centre to a connector 31. Each connector 31 is connected at its opposite end to a point on the periphery of the rotor disc 12; as shown, the ends of the connectors are engaged between flanges of the rotor disc and are connected thereto by means of pivot pins 32 by which the rotor blades are normally retained in position. Hydraulic fluid is supplied to the cylinders 26a through ducts 33 from a common manifold 47. Fluid is supplied by means of a pump to a tank in which the level is controlled by a float mechanism which controls the operation of the pump motor. The fluid in the tank is pressurized by means of air under pressure and the fluid passes to the inlet of a piston type pump, being discharged from the pump to the manifold 47. Means may be provided for heating and cooling the disc to simulate conditions in use of the disc under test. Also a vibration may be superimposed on the disc induced mechanically or by electromagnetic means.