A vibration attenuator for a rotor of an aircraft has a housing adapted for rotation with the rotor about an axis. A first ring is rotatably carried within the housing on a first bearing, a first weight being coupled to the first ring for rotation therewith relative to the housing about the axis. A second ring is rotatably carried by the first ring on a second bearing, a second weight being coupled to the second ring for rotation therewith relative to the housing and to the first ring. A first motor is configured for rotating the first ring relative to the housing, and a second motor is configured for rotating the second ring relative to the housing and to the first ring. The first and second motors are operated to rotate the weights within the housing and position the weights relative to each other for attenuating vibrations.

The invention herein relates to a flywheel capable of high speed rotational operation in excess of 15,000 rpm, the flywheel comprising a composite rotor having a polymeric matrix in which are embedded fibers helically wound at an initial angle with respect to the axis of rotation of the rotor of from about 50° to about 80° and increasing in a stepwise or continuous manner to about 90°.

A piston bolt is formed by divided first and second members, and a first small-diameter portion and a large diameter portion of a common passage are formed in the first member and a second small-diameter portion of the common passage is formed in the second member. This configuration allows the common passage to be processed using a general-purpose method and tool and contributes to reducing the man-hours for the piston bolt.

A fluid damper is provided including a cylinder filled with a damping fluid, a piston base body shiftably guided in the cylinder along a stroke axis, and a valve disk spaced apart from a shell wall of the cylinder. The piston base body divides an inner space of the cylinder into a front space and a rear space along the stroke axis. In the piston base body, there is at least one channel connecting the front space to the rear space in a fluid-conducting manner. The valve disk is shiftably guided along the stroke axis between an opening position unblocking the at least one channel and a closing position closing the at least one channel. The valve disk has a central area extending radially outward from the stroke axis, the central area being free of apertures.

An assembly, a system, and a method for protecting a portion of a pipeline from an impact in an excavation operation creating a void around the portion of the pipeline with a shell assembly are described. The shell assembly includes two half cylinders and fasteners to couple the two half cylinders together. Each half cylinder has a pipe cover shell, an inner shell, and an outer shell. The pipe cover shell is sized to conform to an outer surface of the pipeline. The inner shell is spaced apart from the pipe cover shell and coupled to the pipe cover shell by radially extended inner supports. Each inner support has a crumple component that is weaker than adjacent portions of the inner support. The outer shell is spaced apart from the inner shell with the inner shell disposed between the outer shell and the pipe cover shell.

A method of manufacturing a gas cylinder according to an embodiment of the present invention may include applying a sealant to at least a portion of inner surface of a hollow spindle; inserting a cylinder assembly contacting the inner surface of the spindle through an inlet of the spindle and forming a sealant film on an inner surface of the spindle by frictionally applying the sealant to the inner surface of the spindle; and hardening the sealant film to form a cured film cylinder in contact with the inner surface of the spindle.

A suspension actuator includes a first housing part, a second housing part, a ball screw actuator that is connected to the first housing part and to the second housing part, and an air spring membrane that is connected to the first housing part and to the second housing part. The air spring membrane includes a flexible material and a reinforcing structure that is disposed within the flexible material to resist torsion loads that are applied to the second housing part by the ball screw actuator.

A shock absorber includes a cylinder sealed with a working oil liquid, a piston slidably fitted in the cylinder, a piston rod connected to the piston and extended to the outside of the cylinder, and a plurality of passages through which the working oil liquid flows due to the sliding of pistons therein, and a damping force generating mechanism that is provided in a part of the passages and suppresses the flow of the working oil liquid to generate a damping force. The damping force generating mechanism includes a valve body through which the passage penetrates, an annular seat that projects from the valve body and surrounds the passage, and a disc that can be seated on the seat. A contact width at which the disc and the seat come into contact with each other is different depending on a position in the circumferential direction. As a result, it is possible to obtain a shock absorber capable of suppressing a sudden change in damping force before and after the opening of the disc valve without having a complicated structure.

An assembly for damping switching movements has a housing, which physically surrounds at least one piston, and which at least partly physically surrounds at least one rod. The rod is movable relative to the housing. The piston delimits a first fluid volume, which is fluidically connected to a second fluid volume by way of a throughflow opening. The rod is formed at one end as a hollow tube and physically surrounds the first fluid volume. The piston is guided in the hollow-tubular end of the at least one rod. A method for damping switching movements in a high-voltage circuit breaker includes decreasing a damping rate of the assembly for damping in a period in the time profile of the switching movement, in particular after a previous increase in the damping rate during the switching movement.

Provided is a valve device and a shock absorber that can prevent them from being in a failure state at the normal time and can freely set a passive valve even when both pressure control and passage opening/closing are performed by a solenoid valve. For this reason, the valve device includes a first passage and a second passage connected downstream of the pressure introducing passage, a solenoid valve that opens the first passage to control the upstream pressure and closes the second passage when energized, and that closes the first passage and opens the second passage when not energized, and a passive valve provided downstream of the solenoid valve in the second passage.