Snecma Moteurs

Snecma

Alain Chatel

Dominique Raulin

Fabrice Marois

Laurent Gilles Dezouche

Philippe Joly

Florent Raine

Alain Bouron

The manufacturing cost of the control device is relatively low. This device comprises mainly a first end () of a control lever () provided with a drive hole () that drives the driving part () of a blade () through a first contact area (). The close contact between these two parts in this area is obtained using a play compensation plate () bearing on a side part () of the control lever (), and fixed to the assembly using a nut () screwed onto the external pivot () of the blade (). For application on turbomachines.

Control lever attachment with play compensation for blades with variable setting angles

The pitch control mechanism (controlling the angular position) for stator blades in a turbojet may be adjusted separately for two adjacent stages of blades controlled by a common actuatorTo achieve this, the synchronization barlocated between the mechanisms leading to the two stages is inclined, this inclination being determined by a pinand grooveconnection with the casing, while another pinand grooveconnection is arranged between the synchronization barand one of the mechanisms. Strongly non-linear displacement laws between the two mechanisms may thus be controlled depending on the shapes and directions of the grooves.

Variable pitch device for two blade stages fixed onto a turbojet

A device for controlling variable-pitch vanes in a turbomachine comprises links connecting the radial pivots of the vanes to radial fingers carried by semicircular elements and bridges of a control ring, the links being mounted in ball-and-socket manner on the radial fingers which are fixed to the control ring. This form of mounting enables all the vanes associated with the control ring to be set to the same angular pitch.

Device for controlling variable-pitch vanes in a turbomachine

A spring ( ) of angular shape is placed between the lug ( ) of a connecting rod ( ) controlling the orientation of a stator blade and the pivot ( ) of said blade, such that its edge ( ) bends against one edge face ( ) of the connecting rod ( ) and the washer ( ) moves the pivot ( ) in the play of the bore ( ) of the connecting rod and sets and maintains the contact between two plane faces ( and ), so as to reduce the differences in angular displacements between the connecting rod and pivot due to the play remaining in the bore ( ).

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Vaux Le Penil, France

Alain Chatel