A vibration suppression unit for an aircraft comprising a mass having a center of mass, a first rotor, a second rotor, a first coupling between the first rotor and the mass, a second coupling between the second rotor and the mass, the first and second couplings having first and second coupling centers offset perpendicularly from a central axis of rotation by different radial distances and offset in axially from the center of mass with respect to the central axis by different axial distances, the first and second coupling centers having a selectively variable displacement angle defined by the angle between lines extending between the central axis of rotation and the first coupling center and the second coupling center, respectively, wherein the first rotor and the second rotor are controllable to produce a vibration control force vector having a controllable magnitude and frequency about the central axis.

A vibration control device of a plate-like member 11 includes: a plurality of piezoelectric element actuators 14; at least one piezoelectric element sensor 15; and a control circuit 17 that performs feedback control of operation of the piezoelectric element actuators 14 based on an output voltage of the piezoelectric element sensor 15 so as to suppress vibration of the plate-like member 11. A layout of the piezoelectric element sensor 15 and the piezoelectric element actuators 14 is set such that anti-resonance occurs in an output voltage of the piezoelectric element sensor 15 in a range where the vibration frequency of the plate-like member 11 is equal to or less than a predetermined value. Therefore, generation of noise can be prevented at the frequency. As a result, a gain can be increased at a control target frequency. Therefore, vibration can be suppressed, and noise can be reduced.

The invention relates to an agricultural apparatus (1) for spreading material, such as fertilizers, plant protection products, or seed, comprising a distributor linkage (10) which can be folded on both sides, comprising a central part (11), where the central part (11 ) is connected in a rotationally fixed manner to the agricultural apparatus (2 ), two intermediate frames (12a,b) connected to the central part (11) in particular by joints, two lateral booms (13a,b) connected to the respective intermediate frames (12a,b), and a damping assembly (19) for damping motions of the first boom (13a) and the second boom (13b) in the direction of travel of the agricultural apparatus (1), where the damping assembly connects the intermediate frames (12a,b) to one another in particular independently of the central part (11), or where the damping assembly (19) connects the respective intermediate frames (13a,b) to the central part (11).

A damper valve with an adjustable effective stiffness of a shim. The damper valve includes a piston. The piston has a fluid path formed therethrough. A shim is disposed proximate the fluid path formed through the piston. A stiffness adjustment feature is coupled to the shim, and the shim is disposed between the piston and the stiffness adjustment feature. The stiffness adjustment feature is configured to adjust the effective stiffness of the shim without affecting a preload applied to the shim.

Provided are a reliable high-voltage system and a failure diagnosis method thereof, in which a vibration damping mechanism using an electrorheological fluid as a working fluid is a load, and can prevent electric shock due to leakage current and the influence on surrounding electronic devices. There are provided a first circuit that includes a power source and a ground, a second circuit that is magnetically coupled to the first circuit via a transformer and includes a load connected to the ground, a controller that is connected to the ground, a third circuit that is connected to the second circuit and the ground, a first resistor that is provided between a connection point at a high potential end of the second circuit and the ground, and a second resistor that is provided between a connection point at a low potential end of the second circuit and the ground, and has a resistance value different from a resistance value of the first resistor.

A solar tracker system includes a torque tube, a solar panel assembly attached to the torque tube, a housing defining a chamber and a fluid passageway extending from the chamber, and an active lock connected to a seal configured to prevent a flow path of fluid while in a sealed state and allow the flow path of fluid in an unsealed state. The system further includes a controller in communication with the torque tube and the active lock. The controller is programmed to receive a command to place the solar panel assembly in a stowed position, instruct the torque tube to rotate the panel assembly to a stowed angle corresponding to the stowed position, monitor a current angle of the panel assembly, compare the current angle to the stowed angle, and instruct the seal to transition to the sealed state when the current angle is equal to the stowed angle.

A shock absorber and method of controlling a shock absorber, wherein the shock absorber comprises damper body having an inner tube and an outer tube and a piston rod having a main piston arrangement arranged inside the inner tube. The shock absorber further comprises two separate electrical continuously controlled valves (CES1, CES2), one for compression and one for rebound flow, arranged with passive valves coupled in series with and downstream of the electronically controlled valves and with a communication chamber coupling these valves to a pressurizing chamber.

The invention relates to an assembly for damping vibrations of a structure (I), having a wall element (5a, 5b, 5c, 5d) to be fitted in a upright position, a casing element (Sa, Sb, Sc, 8d) and a damping device (22a, 22b, 22c, 22d), which is connected to the casing element (Sa, Sb, Sc, 8d) and to the wall element (5a, 5b, 5c, 5d) such that a relative movement between the wall element (5a, 5b, 5c, 5d) and the casing element (Sa, Sb, Sc, 8d) is transmitted to the damping device (22a, 22b, 22c, 22d). The damping device (22a, 22b, 22c, 22d) is designed to damp a vibrating movement of the wall element (5a, 5b, 5c, 5d) in a damping direction and is arranged such that the damping device is oriented substantially parallel to a surface of the wall element (5a, 5b, 5c, 5d). The invention further relates to a method for damping vibrations of a structure.

A ring circumscribing a moveable rod of a hydraulic damper, the moveable rod defining a central axis, the ring comprising a first circumferential surface, a second circumferential surface, a first finger, a second finger, a first flange, and a second flange. The first finger and the first flange defining a first end of the ring. The second finger and the second flange defining a second end of the ring.

The present disclosure discloses an electromagnetic multistage adjustable variable inertance and variable damping device. Iron cores are magnetized by winding electromagnetic coil windings outside the iron cores and applying an electric current action to the electromagnetic coil windings, and air gap magnetic fields are generated by the magnetized iron cores and permanent magnets in air gaps to cause the variation of shear damping forces between a driving shear plate and magnet yokes and between driven shear plates and magnet yokes, which avoids that the mechanical properties of an inerter cannot be fully utilized due to the friction caused by mutual contact among parts, thereby realizing multistage real-time adjustability of an instance coefficient and a damping coefficient of the device.