Shock Absorbers, Linear Dampers and Dashpots

Shock absorbers, linear dampers, and dashpots are devices designed to provide absorption of shock and smooth deceleration in linear motion applications. They may be mechanical (e.g., elastomeric or coil spring) or rely on a fluid (gas, air, hydraulic), which absorbs shock by allowing controlled flow from outer to inner chamber of a cylinder during piston actuation. The piston rod is typically returned to the unloaded position with a spring.  Shock absorbers typically contain both a fluid or mechanical dampening system and a return mechanism to the unengaged position. They vary from small device application to large industrial and civil engineering uses.  Linear dampers is an inclusive term that can be applied to many forms of dashpots and shock absorbers; typically used for devices designed primarily for reciprocating motion attenuation rather than absorption of large shock loads.  Dashpots are typically distinct in that while they use controlled fluid flow to dampen and decelerate motion, they do not necessarily incorporate an integral return mechanism such as a spring. Dashpots are often relatively small, precise devices used for applications such as instrumentation and precision manufacturing.

Shock absorbers or damper types for shock absorbers, linear dampers and dashpots can be hydraulic, air, gas, or elastomeric.  The absorption or damping action can be compression or extension.  Important parameters to consider when searching for shock absorbers, linear dampers and dashpots include absorber stroke, compressed length, extended length, maximum force (P1), and maximum cycles per minute.  Absorber or spring stroke is difference between fully extended and fully compressed position.  Compressed length is the minimum length of shock (compressed position).   Extended length is the maximum length of shock (extended position).  The maximum rated force for shock absorber or damper, referred to as the P1 force.  The maximum cycles per minute are the rated frequency of compression/extension cycles.

Important physical specifications to consider when searching shock absorbers, linear dampers and dashpots include the cylinder diameter or maximum width, the rod diameter, mounting, and body material.  The cylinder diameter or maximum width refers to the desired diameter of housing cylinder.  The rod diameter refers to the desired diameter of extending rod.  Mounting choices include ball and socket, rod end, clevis, eyelet, tapered end, threaded, and bumper or rod end unattached.  Choices for body materials include aluminum, steel, stainless steel, and thermoplastic.  Common features for shock absorbers, linear dampers and dashpots include adjustable configuration, reducible, locking, and valve.  An adjustable configuration allows the user to fine tune desired damping, either continuously or at discrete settings.  A reducible shock absorber, linear damper or dashpot has an adjustment style for gas shocks in which gas is let out to permanently reduce force capacity.  In a locking configuration the position can be locked at ends or in the middle of stroke.  Valves can be included for fluid absorbers, a valve or port, which can be used to increase or decrease fluid volume or pressure.