A vibration isolator includes a first conical disc spring member having a first end and a second end. A first-end spacer in contact with the first spring member first end, and a second-end spacer in contact with the first spring member second end. A second conical disc spring member has a first end and a second end. The second spring member first end is in contact with the first-end spacer. Another second-end spacer is in contact with the second spring member second end. A flexible housing of the isolator defines an interior. The housing is in contact with and extends between the second-end spacer and the other second-end spacer so that the first-end spacer and the first and second spring members are received in the housing interior. The housing includes a plurality of spaced-apart through holes formed therealong between the second-end spacer and the other second-end spacer.

The invention relates to a composite shock absorber for a polycrystalline diamond compact bit, comprising a drilling tool body having a water inlet, an impact body having a water outlet and forming a shock absorption cavity, a disc spring group having an annular pressing sleeve, a cylindrical torsion bar spring which has an external thread and a spline, is connected to the drilling tool body through threads and extended into an impactor and connected thereto through the spline, and the annular pressing sleeve, wherein bit vibration impact force is transmitted therebetween through a torsion transmission joint, and a bearing group is arranged between the lower end surface of the annular pressing sleeve and an annular step of the impact body. The composite shock absorber can weaken damage of the slippage effect to polycrystalline diamond compact cutting teeth, absorb axial vibration from a drill stem and prolong the service life of the bit.

The invention relates to a composite shock absorber for a polycrystalline diamond compact bit, comprising a drilling tool body having a water inlet, an impact body having a water outlet and forming a shock absorption cavity, a disc spring group having an annular pressing sleeve, a cylindrical torsion bar spring which has an external thread and a spline, is connected to the drilling tool body through threads and extended into an impactor and connected thereto through the spline, and the annular pressing sleeve, wherein bit vibration impact force is transmitted therebetween through a torsion transmission joint, and a bearing group is arranged between the lower end surface of the annular pressing sleeve and an annular step of the impact body. The composite shock absorber can weaken damage of the slippage effect to polycrystalline diamond compact cutting teeth, absorb axial vibration from a drill stem and prolong the service life of the bit.

Systems and methods for limiting transmission of vibrations and forces causing vibrations from one element to another are provided. A vibration isolator may include a compressible inner member and an outer member compressible with the inner member. The outer member may be positioned at least partially around the inner member to provide lateral support to the inner member. The outer member may maintain a consistent diameter and compression force when in a compressed state. The outer member may include a tube with a zero or near-zero Poisson's ratio.

The present invention provides a spring mechanism which can elastically deform an elastic deformation part with a film shape of a transducer into a shape having high symmetry, and also can be structured in a small size. A spring mechanism 2 includes: a cylindrical member 7 that is provided so as to extend toward a first element member 21 from an elastic deformation part 11 of a transducer 5, and also is arranged so as to slidably penetrate the first element member 21 in the direction of a central axis line C of the elastic deformation part 11; and a rod member 32 that is provided so as to extend toward the cylindrical member 7 from a second element member 22 side, and is slidably inserted in the cylindrical member 7 in the direction of the central axis line C of the elastic deformation part 11.

The present invention provides a spring mechanism which can elastically deform an elastic deformation part with a film shape of a transducer into a shape having high symmetry, and also can be structured in a small size. A spring mechanism 2 includes: a cylindrical member 7 that is provided so as to extend toward a first element member 21 from an elastic deformation part 11 of a transducer 5, and also is arranged so as to slidably penetrate the first element member 21 in the direction of a central axis line C of the elastic deformation part 11; and a rod member 32 that is provided so as to extend toward the cylindrical member 7 from a second element member 22 side, and is slidably inserted in the cylindrical member 7 in the direction of the central axis line C of the elastic deformation part 11.

A bottomhole assembly includes: a drill bit operable to vibrate when engaged with a formation and rotated; and a suspension sub including: a stator barrel for connection to a pipe string; a traveler barrel for connection to the drill bit; a slip joint longitudinally coupling the traveler barrel to the stator barrel while allowing movement of the traveler barrel between an extended position and a retracted position; a torsional joint connecting the traveler barrel to the stator barrel at and between the positions; and one or more springs disposed between the stator barrel and the traveler barrel. The suspension is tuned relative to the drill bit to: dampen the vibration of the drill bit when the BHA is rotated at a first angular velocity; and resonate the vibration of the drill bit when the BHA is rotated at a second angular velocity, thereby imparting percussive energy to the drill bit.

A bottomhole assembly includes: a drill bit operable to vibrate when engaged with a formation and rotated; and a suspension sub including: a stator barrel for connection to a pipe string; a traveler barrel for connection to the drill bit; a slip joint longitudinally coupling the traveler barrel to the stator barrel while allowing movement of the traveler barrel between an extended position and a retracted position; a torsional joint connecting the traveler barrel to the stator barrel at and between the positions; and one or more springs disposed between the stator barrel and the traveler barrel. The suspension is tuned relative to the drill bit to: dampen the vibration of the drill bit when the BHA is rotated at a first angular velocity; and resonate the vibration of the drill bit when the BHA is rotated at a second angular velocity, thereby imparting percussive energy to the drill bit.

The disc spring is a disc spring for being fitted on a rotary shaft and includes: an annular body portion; a claw portion protruding inward in a radial direction from an inner peripheral edge of the body portion, wherein the claw portion gradually extends toward one side in an axial direction as it goes inward in the radial direction, and at least a tip part of the claw portion is provided with a hole.

A damper for a rotor hub for a rotorcraft can include a housing, a piston resiliently coupled to the housing with a first elastomeric member and a second elastomeric member, a plurality of conical members, a fluid, and an orifice.