Abstract: The invention relates to a vibration damper, in particular for a helicopter rotor, the damper comprising both a driving element and a rigid element and including a damper assembly functionally interconnecting the driving element and the rigid element, the damper assembly comprising firstly a hydraulic damper device disposed in at least one viscous fluid cavity and a laminated flexible device. The hydraulic damper device comprises first and second sets of interleaved plane vanes. In the invention, the hydraulic damper device also has at least one damper element which is disposed in one of said viscous fluid cavities and which is secured to the driving element, said damper element presenting an outer outline which tapers going away from a base situated beside one axial end of the damper towards an apex situated beside the sets of plane vanes.

Abstract: The invention relates to a combined ball-and-damper device for mounting between firstly a flexible spar connecting a helicopter blade to a rotor hub and secondly a torque tube for controlling the pitch of said blade, the device comprising two individual modules each comprising a plane laminated damper and a laminated ball, the laminated damper extending between an outer end and an inner end and presenting at its outer end an element for connection to the torque tube for controlling the pitch of said helicopter blade, and the laminated ball presenting a stack of metal and elastomer layers, the laminated damper being secured at its inner end to an outer end of the ball whose own inner end presents an element for fixing to said flexible spar, the device including at least one connection element providing a stiffening connection between the outer ends of the two balls of the two individual modules making up the combined device.

Abstract: The invention relates to a combined ball-and-damper device for mounting between firstly a flexible spar connecting a helicopter blade to a rotor hub and secondly a torque tube for controlling the pitch of said blade, the device comprising two individual modules each comprising a plane laminated damper and a laminated ball, the laminated damper extending between an outer end and an inner end and presenting at its outer end an element for connection to the torque tube for controlling the pitch of said helicopter blade, and the laminated ball presenting a stack of metal and elastomer layers, the laminated damper being secured at its inner end to an outer end of the ball whose own inner end presents an element for fixing to said flexible spar, the device including at least one connection element providing a stiffening connection between the outer ends of the two balls of the two individual modules making up the combined device.

Abstract: The invention relates to a vibration damper, in particular for a helicopter rotor, the damper comprising both a driving element and a rigid element and including a damper assembly functionally interconnecting the driving element and the rigid element, the damper assembly comprising firstly a hydraulic damper device disposed in at least one viscous fluid cavity and a laminated flexible device. The hydraulic damper device comprises first and second sets of interleaved plane vanes. In the invention, the hydraulic damper device also has at least one damper element which is disposed in one of said viscous fluid cavities and which is secured to the driving element, said damper element presenting an outer outline which tapers going away from a base situated beside one axial end of the damper towards an apex situated beside the sets of plane vanes.

Abstract: The present invention relates to a vibration damper, in particular for a helicopter rotor, the damper comprising a driving element having a "main" axis and a rigid element, and including a damping assembly functionally interconnecting the driving element and the rigid element to damp vibrations in at least one direction perpendicular to said main axis. The damper includes a hydraulic damper device having first and second sets of plane laminations each having its plane perpendicular to the main axis, the laminations of the first and second sets being interleaved and narrowly spaced apart so as to present viscous damping zones each situated between one of the laminations of the first set and one of the laminations of the second set. The damper includes an elastic element having low stiffness parallel to the main axis so as to decouple compression excitation between the driving element and the rigid element.