Abstract: A damper includes: a line-shaped member wound around an outer peripheral surface of a piston which makes a relative motion in a cylinder; and a viscous fluid made to adhere to the line-shaped member and exhibiting viscous damping force. The relative motion of the cylinder and the piston produces tension, and in the line-shaped member, as an amplitude is smaller, its contiguously wound portions each try to deform to twist along a circumferential direction of the line-shaped member itself, and as the amplitude is larger, the contiguously wound portions try to deform as a unit. When the amplitude is small, frictional resistance decreases, resulting in smooth motion of the piston, and appropriate damping force is obtained due to the viscous damping force of the viscous fluid. When the amplitude is large, as a result of the increased tendency that the contiguously wound portions of the line-shaped member try to deform as a unit, friction damping force acts relatively greatly.
Abstract: A snubber for reducing shock and vibration in down hole tools includes a housing having an axis and a chamber. A piston is mounted in the chamber for axial movement therein. The piston includes a shaft extending therefrom to an exterior of the housing. An axial spring element is mounted between the piston and the housing. Both the piston and the chamber include non-cylindrical portions.
Abstract: An elastomer damper (20) for damping movement between two relatively moveable members, such as shimmy motion between components in an aircraft landing gear assembly (10). The damper (20) includes a housing (24) having an internal cavity (36) with a cylindrical interior surface (34) and an opening (41), and a member assembly (28) moveable relative to the housing (24) having an elongated shaft (30) received through the opening (41) with a piston head assembly (32) mounted thereon. The piston head assembly (32) has a annular support element (46) received over the shaft (30) with a sleeve-like elastomer member (48) received over it. The elastomer member (48) engages the interior surface (34) in an interference fit relationship thereby radially precompressing the elastomer element (48) in the range of between about 5% and 15%. Low friction washers (50a, 50b) are preferably positioned adjacent to the ends of the elastomer ember (48) and the support member (46).
Abstract: An inverted strut damper includes an external cylinder which has an expanded midsection and a vertically moveable damper tube arranged concentrically within the outer cylinder. The outer cylinder and tube arrangement form a lubricating oil supply reservoir. Disposed at a top and a bottom of the outer cylinder is a respective oil seal and bearing arrangement. The upper bearing is adjacent to the lubricating oil reservoir and upon upper movement of the damper tube, oil is supplied to the upper bearings and seal.