Solar tracker systems include a torque tube, a column supporting the torque tube, a solar panel attached to the torque tube, and a damper assembly. The damper assembly includes an outer shell surrounding an inner shell and defining an outer fluid channel. A piston is positioned within the inner shell and moveable relative thereto. A locking valve of the damper assembly includes a shaft extending into a chamber and a seal attached to the shaft. The shaft is selectively moveable axially within the chamber along an extension axis between an unsealed position in which the seal is spaced from a chamber wall and a flow path is defined that extends from within the inner shell, through the chamber, and to the outer fluid channel, and a sealed position in which the seal contacts the chamber wall and the locking valve obstructs the flow path.

The present application relates to self-adjusting damping vibration absorbers, in particular to a self-adjusting damping vibration absorber for while-drilling instruments and an adjusting method thereof. The self-adjusting damping vibration absorber includes a vibration monitor and controller tool and a vibration absorber body. The vibration monitor and controller tool is mounted inside the downhole while-drilling instrument, one end of the vibration absorber body is connected to the vibration monitor and controller tool through an insulating connector, the joint is provided with an insulating pad, the other end is connected to a sensor or circuit board tool that needs vibration damping, and the inside of the vibration absorber body is provided with a damping adjustment layer made of an electroactive polymer. By controlling the magnitude of an applied voltage, the damping adjustment can be realized, and the damping adjustment layer has the characteristics of high response speed and high control precision. The self-adjusting damping vibration absorber of the present application can adjust the vibration absorber damping according to the changes of the downhole vibration and temperature, so that the vibration absorber inherent frequency avoids or is far away from the vibration frequency of the downhole while-drilling instrument so as to avoid resonance, and thereby, the vibration absorber achieves the best vibration damping effect.

The invention relates to a device for damping vibrations in a structure, comprising a first element (2) rotatably mounted around a rotational axis (3) and a second element (4) rotatably mounted around said rotational axis (3), a radius (R1) of a circle portion (10) delimitating the first element with respect to the rotational axis, being smaller than a radius (r2) of a circle portion (16) delimitating the second element with respect to the rotational axis, the first element being called inner element, and the second element being called outer element.

Provided is a matrix type double parallel capillary tube shock absorber with a variable system natural frequency, wherein on a pipeline between oil supply ports of an upper oil compartment (14) and a lower oil compartment (16), a capillary tube parallel type damping associated section and a capillary tube parallel type system natural frequency associated section are successively connected from top to bottom; the capillary tube parallel type damping associated section comprises four capillary tubes connected in parallel, with each capillary tube being connected in series with a solenoid valve so as to control the operation of the capillary tube; the capillary tube parallel type system natural frequency associated section comprises four capillary tubes connected in parallel, and each of the four capillary tubes is connected in series with a solenoid valve so as to control the operation of the capillary tube; the diameter of the smallest capillary tube of the frequency adjustment section is much larger than the diameter of the capillary tube of the resistance adjustment section; and in a matrix type operation state table, the configuration value S.sub.mn of the solenoid valves of the frequency adjustment section is selected according to situations, and by way of changing the mass, the problem of the system natural frequency of a hydraulic shock absorber for a vehicle being not adjustable or having a small adjustable range can be solved. Further provided is a method for operating a matrix type double parallel capillary tube shock absorber with a variable system natural frequency.

A modular electronic damping control system is described and includes a damping component located at a vehicle suspension location. The modular electronic damping control system also includes a control system configured to control the damping component, and determine the type of damping component present. Also, the control system is configured to automatically tune a vehicle's suspension based on the type of damping component present, and automatically monitor the damping component and determine when a change has been made to the damping component so that the control system can then automatically re-tune the vehicle's suspension based on the change to the damping component.

A vibration suppression method for a servo motor and a load multistage drive system is provided. For a number N of fixed vibration frequencies and one vibration frequency varying with a load position existing in a multistage drive mechanism, a number of N+1 vibration suppression filters are adopted, and each filter is configured to eliminate a corresponding vibration frequency. Fixed vibration frequencies and a vibration frequency varying with a load position in a multistage drive system are measured by using an offline method, and the varied vibration frequencies are made into a two-dimensional table related to the load positions. The fixed vibration frequencies are eliminated by using fixed-frequency parameter vibration suppression filters; and the varied vibration frequencies are eliminated by using a variable-frequency parameter vibration suppression filter, and the vibration frequencies are obtained in real time according to the load positions and the two-dimensional table.

A two-wheel mobile apparatus that is movable on land and water includes a cabin and a propulsion unit. The cabin is configured to be watertight to a height above a waterline when the mobile apparatus moves on water. Further, the cabin accommodates an occupant and isolates the occupant from the outside of the cabin. The propulsion unit includes a rotatably driven impeller and moves the mobile apparatus on water. An orientation detection unit that detects orientation of the mobile apparatus. A tilt correction unit corrects tilt of the mobile apparatus on land. An oscillation reduction unit reduces oscillation of the mobile apparatus on water. An orientation control unit switches between actuation of the tilt correction unit and actuation of the oscillation reduction unit based on a detection value of the orientation detection unit.

A frictional damper includes a housing having a longitudinal axis, a tappet which is movable along the longitudinal axis, a frictional unit for generating a direction-dependent frictional force on the tappet, wherein the frictional unit includes at least one friction lining lying rubbingly against the tappet, and a switching unit for variably setting the frictional force.

A method for controlling a semi-active engine mount is provided to increase both NVH performance and driving performance of a vehicle and reduce noise and vibration generated under specific driving conditions. The method includes storing real-time vehicle speed data at intervals of a predetermined time and determining whether an engine is in an idling state. In response to determining that the engine is in the idling state, determining whether a current driving state of the vehicle corresponds to predetermined conditions in which noise and vibration performance is prioritized based on vehicle speed change information. The semi-active engine mount is adjusted to be in an on state, upon determining that the current driving state of the vehicle in the idling state of the engine corresponds to the predetermined conditions.

A damper assembly for an angle of attack sensor includes a rotor including a conical portion, a damper housing in which the rotor is positioned, the damper housing being configured to be adjusted axially with respect to the rotor and including a tapered interior surface that matches a profile of the conical portion, and a locking mechanism adjacent the damper housing.