How Shock Absorbers Work?

ARC Industrial shock absorbers are hydraulic components that reliably decelerate moving masses. This help machines to work faster and reduce maintenance costs. ARC Industrial shocks work by restricting oil flow through a series of controlled passage. When the piston rod is pushed into the cylinder, oil is displaced through these passage, which are progressively reduced. As a result, the speed gradually decreases as the shock absorber is compressed and prevents serious damage to machine. Hence converting kinetic energy of a load into heat which is dissipated into the atmosphere. They stop a moving load with no rebound and without transmitting potentially damaging shocks to equipment. The advent of high speed equipment and machinery has brought with it numerous problems associated with slowing and stopping masses of various forms. The ARC hydraulic shock absorber has proven itself to be one of the most satisfactory means of solving these problems.

Why Industrial Shock Absorbers?

Motion control often requires stopping a moving load smoothly. A rubber snubber, a compression spring, and a dashpot all can accomplish this by absorbing energy. The snubber and spring store energy and release it after they are compressed, resulting in a rebound. A dashpot is a fluid-filled cylinder with an opening through which fluid may escape in a controlled manner. Any force acting against the piston in the cylinder encounters high resistance from the fluid at the beginning of the stroke, then much less as the piston retracts. However, none of these three items dissipate the energy uniformly. The impact of a moving load against a resisting force produces peak forces which are transmitted to plant equipment, or to the load itself. In order to dissipate the energy uniformly, the use of a shock absorber is required. The optimum solution is achieved by an ARC industrial shock absorber. This utilises a series of metering orifices spaced throughout its stroke length and provides a constant linear deceleration with the lowest possible reaction force in the shortest stopping time.

  • Hydraulic Dashpot (High stopping force at start of the stroke).
    With only one metering orifice the moving load is abruptly slowed down at the start of the stroke. The braking force rises to a very high peak at the start of the stroke (giving high shock loads) and then falls away rapidly.

  • Springs and Rubber Buffers (High stopping forces at end of stroke).
    At full compression. Also they store energy rather than dissipating it, causing the load to rebound back again.

  • Air Buffers, Pneumatic Cylinder Cushions (High stopping force at end of stroke).
    Due to the compressibility of air these have a sharply rising force characteristic towards the end of the stroke. The majority of the energy is absorbed near the end of the stroke.

  • ARC Industrial Shock Absorbers (Uniform stopping force through the entire stroke).
    The moving load is smoothly and gently brought to rest by a constant resisting force throughout the entire shock absorber stroke. The load is decelerated with the lowest possible force in the shortest possible time eliminating damaging force peaks and shock damage to machines and equipment. This is a linear deceleration force stroke curve and is the curve provided by ARC industrial shock absorbers. In addition they considerably reduce noise pollution.

Selecting a shock absorber

When choosing a shock absorber, the most important factor to consider is the type of load to be stopped. Basic types of loads encountered in shock absorber applications include pure inertial, free-falling, rotating, and loads subject to an additional propelling force. Load weight and velocity are the next two most important factors in sizing a shock absorber. Additionally, potential shock to equipment, number of impacts per unit of time, and ambient conditions must be considered to properly select a shock absorber. Application conditions include extreme temperatures, load acceleration, maximum propelling force applied to the load, and time limitations imposed on the equipment. Time limitations would include minimum and maximum cycle times and the time required for the shock absorber to return to the extended position between strokes. Cycle rate is another important consideration. If the shock absorber must handle too many impacts within a given time, it will overheat, resulting in poor performance and premature failure. Rapid cycling may heat the fluid, reducing its ability to dissipate energy. As a safety feature, most manufacturers recommend that shock absorbers be sized to 50% to 60% of capacity. Because the amount of impact the shock absorber can accommodate is inversely proportional to the length of its stroke; doubling stroke length will cut the impact of the load in half.