Crack detecting means for rotor blades of rotary wing aircrafts
US4026660A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 1976 |
| Grant date | May 31, 1977 |
| Priority date | — |
| Expiry date | Apr 13, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64C27/007
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
Rotary wing aircrafts include one or more rotors having a plurality of rotary blades. Each of the rotor blades has crack sensor in the form of an induction coil or conductive wire. The crack sensor is connected with a further induction coil to form a circuit of which inductance is changed when a crack is produced in the associated rotor blade. On a stationary part such as a stationary swash plate of the rotorcraft, there is provided a stationary induction coil which is brought into cyclical and electromagnetical co-operation with the further induction coil on the rotor as the rotor rotates. The stationary induction coil is connected with a load resistor and an oscillator in such a way that cracks in the rotor blades can be detected in the form of a voltage change at the load resistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.