US 12,313,596 B2
Method for the nondestructive crack testing of surfaces of rotor blade-receiving blade reception slots of a rotor, and ultrasound device
Michael Clossen-von Lanken Schulz, Issum (DE); and Stefan Obermayr, Duisburg (DE)
Assigned to Siemens Energy Global GmbH & Co. KG, Bayern (DE)
Appl. No. 17/796,663
Filed by Siemens Energy Global GmbH & Co. KG, Munich (DE)
PCT Filed Jan. 15, 2021, PCT No. PCT/EP2021/050781
§ 371(c)(1), (2) Date Jul. 31, 2022,
PCT Pub. No. WO2021/160369, PCT Pub. Date Aug. 19, 2021.
Claims priority of application No. 10 2020 201 671.2 (DE), filed on Feb. 11, 2020.
Prior Publication US 2023/0333060 A1, Oct. 19, 2023
Int. Cl. G01N 29/04 (2006.01); G01N 29/22 (2006.01); G01N 29/26 (2006.01); G01N 29/265 (2006.01)
CPC G01N 29/043 (2013.01) [G01N 29/225 (2013.01); G01N 29/262 (2013.01); G01N 29/265 (2013.01); G01N 2291/044 (2013.01); G01N 2291/106 (2013.01); G01N 2291/2693 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method for nondestructive crack testing of surfaces of blade receptacle slots of a rotor, said slots receiving rotor blades, wherein the blade receptacle slots are arranged in a manner distributed at uniform distances along a periphery of the rotor and the rotor blades received in said slots are spaced apart from one another in such a way that an externally accessible crescent- or strip-shaped rotor surface section extends in each case between adjacently arranged rotor blades, the method comprising:
a) positioning an ultrasonic device comprising a housing defining a guide rail on a rotor surface section extending between two rotor blades in such a way that the guide rail extends along at least one blade receptacle slot to be checked, and securing the guide rail, with the ultrasonic device comprising an ultrasonic test head holder to which an ultrasonic test head is secured, a push rod secured to the ultrasonic test head holder, a handle fixedly positioned on the push rod and projecting substantially axially outward from the push rod, and a further handle fixedly positioned on the housing and projecting substantially axially outward from the housing;
b) positioning the ultrasonic test head in such a way that the ultrasonic test head is oriented in the direction of at least one blade receptacle slot to be tested and is movable in a manner guided along a trajectory predefined by the shape of the guide rail;
c) while an operator is holding the further handle with one hand to stabilize the ultrasonic device, the ultrasonic test head is manually moved with the operator's other hand holding the handle positioned on the push rod along the trajectory in an installed state of two adjacently arranged rotor blades and at the same time checking the surface of the blade receptacle slot to be tested for a presence of cracks using the ultrasonic test head, wherein cracks that are present are acquired in terms of data using the ultrasonic test head;
d) storing the acquired data;
e) repeating steps a) to d) for checking the surfaces of further blade receptacle slots for the presence of cracks; and
f) diagnosing a rotor state on the basis of the data stored in step d).