A shock absorber has a first and second end surfaces opposite to each other in an axial direction, and a plurality of connection surfaces. The first end surface is an N-sided polygon (N is an integer of 3 or more and the second end surface is an M-sided polygon (M is an integer of 4 or more and more than N). (M−N) vertices are provided at intermediate positions in the axial direction on a circumferential surface defined by the plurality of connection surfaces. From the vertices, one first ridgeline reaches one vertex of the first end surface and two second ridgelines reach a corresponding one of two vertices of the second end surface. The remaining vertices are connected to each other by (2×N−M) third ridgelines. The first ridgeline, the second ridgelines, and the third ridgelines define the plurality of connection surfaces.

Disclosed is a damper structure in contact with a connection unit for coupling a first coupling structure part and a second coupling structure part, including a damper part formed of an elastic material and at least one fixing part coupled to at least one surface of the damper part and protruding outward, and coming into contact with the connection unit and moving toward the damper part by pressure applied by the connection unit when the connection unit is separated or fastened.

Disclosed is a damper structure in contact with a connection unit for coupling a first coupling structure part and a second coupling structure part, including a damper part formed of an elastic material and at least one fixing part coupled to at least one surface of the damper part and protruding outward, and coming into contact with the connection unit and moving toward the damper part by pressure applied by the connection unit when the connection unit is separated or fastened.

An elastic wave cloaking lattice-based metamaterial for cloaking an object within a void includes a lattice of connected unit cells arranged to form a void, each unit cell comprising a mass and a plurality of connecting springs, the mass coupled by the plurality of connecting springs to masses in adjacent unit cells, the plurality of connecting springs comprising at least two large springs of a first length and at least two short springs of a second length, the first length greater than the second length, the springs and masses having relational and mechanical characteristics to facilitate elastic wave cloaking in the totality of the lattice. The lattice as a whole has metamaterial properties resulting from the positional relationship and mechanical properties of masses and connecting springs of the unit cells such that the lattice at least partially cloaks an object or material portioned within the void from elastic waves.

The present disclosure discloses a wave-shaped steel plate energy dissipation damper, and a processing method and a mounting method thereof, and belongs to the technical field of energy dissipation and shock absorption of engineering structures. The damper includes a shell, a shock absorption mechanism, and supporting seats. There are two supporting seats which are respectively mounted at a head end and a tail end of the shell. The shock absorption mechanism includes a moving mechanism and at least one wave-shaped steel plate. The wave-shaped steel plate is located in the shell. One end of the wave-shaped steel plate is fixedly connected to the shell. One end of the moving mechanism extends into the shell to fixedly connect the other end of the wave-shaped steel plate. The other end of the moving mechanism is fixedly connected to the bottom of the supporting seat located at the tail end of the shell.

An assembly for a hybrid drivetrain of a motor vehicle, having a first torque transmission device and a second torque transmission device connected thereto so as to transmit torque. The first torque transmission device is arranged to be axially spaced apart from the second torque transmission device and the second torque transmission device has a smaller radial extension than the first torque transmission device. An installation space for a drivetrain device is defined radially above the second torque transmission device such that said drivetrain device is delimited axially by the first torque transmission device. A spacer device is arranged between the two torque transmission devices in the torque transmission path for axial spacing and is designed such that an axially definable minimum spacing between the defined installation space and the first torque transmission device is maintained and has a balancing device for compensating for imbalance of the assembly.

An example flywheel energy storage device includes a fiber-resin composite shell having an elliptical ovoid shape. The example device also includes an axially oriented internal compressive support between the axial walls of the shell. The example device also includes an inner boss plate and an outer boss plate on each side of the shell. The example device also includes a plurality of radially oriented, fiber-resin composite helical wraps forming the shell and coupling the shell to the inner and outer boss plates for co-rotation and torque transfer. The example device also includes boss plate attachments on internal boss plate supports to mount the shell for co-rotation and torque transfer via resin bonding, friction, and compression between the inner and outer boss plates.

A magnetorheological apparatus includes a flexible body formed of an elastomer material, a plurality of cell cavities defined by the flexible body, a magnetorheological (MR) fluid disposed within each cell cavity of the plurality of cell cavities, and a magnetic field inductor positioned adjacent to at least one of the cell cavities. Each cell cavity of the plurality of cell cavities is fluidly encapsulated within the flexible body. The magnetic field inductor is selectively operable to vary a magnetic field, and the MR fluid within the at least one cell cavity is configured to vary a stiffness of the at least one cell cavity in response to the magnetic field.

Provided is a rotary damper having a first valve provided in a first oil passage, the rotary damper including an oil chamber filled with oil; a vane located in the oil chamber; a groove which is formed in the vane and functions as a valve box of the first valve; a valve body of the first valve which moves while being in contact with a bottom surface of the groove; and an elastic body which applies elasticity to the valve body, and causes the valve body to come into contact with a wall surface of the oil chamber when the oil does not flow, in which the bottom surface of the groove is a slope, and thereby the valve body which is in contact with the wall surface when receiving oil pressure from one direction moves away from the wall surface when receiving the oil pressure from an opposite direction.

The present invention relates to an elastic metamaterial for reducing vibrations of a flexible structure such as a main cable of a tether system for controlling an orbit of a satellite revolving around a planet, and a method for improving a vibration reduction performance thereof, and more particularly, to an elastic metamaterial having an improved precision, in which a ratio of a cross-sectional area of a pendulum ring may be adjusted to maintain a frequency characteristic other than a band gap generated due to the elastic metamaterial even in a state where a mass of the pendulum ring is not changed, and a band gap (R_ring) generated due to the pendulum ring of the elastic metamaterial and a band gap (R_beam) generated due to the elastic beams may be combined into one band gap to expand a vibration damping range, and a method for improving a vibration reduction performance thereof.