Device for detecting impacts on an aeronautic propeller assembly The present invention concerns the detection of impacts on an aeronautic propeller assembly made up of a hub and blades.
The object of the invention is to propose a device that permits knowing, over the service life of a blade, during planned maintenance or in case of an incident, whether the blade had been subjected to impacts beyond levels normally encountered in normal use. The invention proposes a reliable and autonomous means for detecting and recording any abnormal impact during use, which means can be consulted during maintenance operations.
In a parallel patent application, filed under the number PCT/FR 02 01727 and whose contents are integrated into the present application by reference, the Applicant has already proposed a device for detecting and recording impacts along several axes of an aeronautic propeller blade, characterized in that it comprises an accelerometer integrated at the center of an aeronautic propeller blade and an electronic module to record any occurrence of impact different from predetermined levels during its service life. The device comprises an accelerometer with at least two axes integrated at the top of the blade equilibration device and it records impacts in two planes perpendicular to the axis of the blade. The accelerometer signals can be transmitted remotely to an electronic module situated in any location whatever and this electronic module makes the recordings, but, advantageously, the electronic module (and all its attached elements such as power supply, which also serves the accelerometer) is also integrated into the root of the blade, so that the device is completely autonomous and integrated with the blade. Thus, according to this parallel application, so as to monitor, count and record abnormal impacts, an accelerometer with 2 or 3 axes connected to an autonomous electronic module supplying the accelerometer is integrated, recovering data sent back from the accelerometer, in order to compare these data to predetermined levels, storing occurrences beyond the predetermined levels in memory and integrating a memory reading device, either by direct connection, or by UHF remote transmission.
The preceding invention therefore proposes integrating, at the root of the blade, a completely autonomous system for measuring and recording impacts beyond predefined thresholds, so as to monitor, by interrogation of the system, the number of cases encountered in use for the different predefined thresholds.
The object of the present invention is to propose a variant of the preceding invention.
The invention achieves its object by means of a device for detecting and recording impacts along several axes on an aeronautic propeller assembly made up of a hub and blades, characterized in that it comprises a plurality of accelerometers, which are integrated at the hub of the aeronautic propeller assembly and are positioned at the respective root of a plurality of blades, as well as an electronic module to record, during its service life, any occurrence of impacts at various predetermined levels. Each accelerometer with one or two axes is integrated at the level of the hub/blade connection in the plane that is most suitable as a function of the number of axes, recording impacts during functioning.
Advantageously, the device comprises at least one accelerometer with at least 2 axes integrated at the hub and positioned in the plane of each blade. In the case where the number of blades is even in number, it is useful to install only one accelerometer in the same plane for two blades.
The invention will be better understood and other advantages and characteristics will be demonstrated upon reading the following description referring to the attached drawings in which:
According to
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FR02/01828 | 5/31/2002 | WO | 8/1/2005 |