Small Shock Absorbers with Greater Potential

September 10, 2012 9:22 am

Cooling lubricants, cutting fluids or cleaning agents can have damaging effects on the working life of a shock absorber. These types of fluids attack the seals of the shock absorber and cause rapid failure of the damping elements. Preventing this is the task of the new PF25 special protective shroud from the ACE Controls
While in the normal case, shock absorbers from ACE can reliably slow down moving masses even in the case of the smallest machine loads, it can occur for example when used in machining centres, that the seals of the damping elements are damaged if these are used in close proximity to the above-designated fluids. Now, with the PF25 special protective shroud, ACE presents miniature shock absorbers with the PF shroud as the first completely protected machine element for machine tools and other similar applications. This attachment is designed for areas where the small shock absorbers of the MC600 Series are used in difficult environmental conditions. The PF25 innovation provides protection in such cases due to the high level of non-reactivity of its material, familiar in many markets as Teflon. Whether used as a windproof and weather-resistant coating, or in the kitchen or of course also in industrial applications, the products coated with polytetrafluoroethylene (PTFE) provide great advantages compared to uncoated products. Now the material also finds advantages in shock absorber technology.
Well-proven, rolling membrane technology of the MC600 Series perfectly protectedThe abbreviation PF, which the ACE design engineers have now designated the newly available shroud, stands for “Protection Flexible”. The flexibility of the protective function can be attributed to the structure in this case and this is embedded in the actual engineering performance by the damping specialists from Langenfeld, Germany. This is because, this innovative accessory, involves a flexible bellows type structure. This item is more stable and considerably stiffer than traditional flexible bellows, but its primary task is the same. In both cases they are attached to machine parts, which are displaced mechanically with respect to each other, in order to protect against external disturbing influences, in particular dirt accumulation and harmful oils. In this case, it is particularly necessary that the seeping of cutting fluid and cooling oil into the sealing system of the small shock absorber of the MC600 Series is prevented. Otherwise the liquid necessary for the machining process could become mixed with the hydraulic oil of the damper
As a result of this, the principle of operation of the rolling membrane technology, especially developed and patented by ACE for this series, would be compromised. This is because this sealing method guarantees that the oil remains in only one separate chamber and it manages to do this without a static O-ring, lip seal, return spring and the normal storage function of an absorber, the accumulator. On the one hand, the hermetically-sealed rolling membrane technology of the design series MC150 to MC600 makes possible the highest level of durability of up to 25 million strokes in normal operating conditions. On the other hand, this type of seal also provides small reset forces popular on handling equipment. If mixing with external oils should occur, this would result in an overfilling of the shock absorber. When additional oil enters the shock absorber and the piston-rod travels through stroke, the piston-rod volume cannot be taken up any longer by the accumulator action and the damper is destroyed. Alternatively the rolling seal membrane is attacked directly by the cutting fluid, swells and is destroyed on loading. The result: The service life duration of the high-quality damper is reduced. Without the rolling seal technology the use of the ACE protective shroud would not be conceivable. This is because the protective shroud, which was especially developed for the small shock absorbers MC150 to MC600, comes without a ventilation hole. Available ex-works the small shock absorbers are designed for use in external pressure ranges up to 8 bars. The air contained in the protective shroud is compressed when the shock absorber goes through stroke. The increased air pressure now acting on the membrane is not a problem for the rolling seal membrane; it even supports the resetting of the piston-rod and the protective shroud, after the mass has been removed. In the case of traditional shock absorbers, sealed by traditional sealing systems, the air would be pressed into the shock absorber. The effects can be easily imagined.
Flexible protection in most varied sectorsThe users of the PF25 succeed in achieving perfect sealing thanks to an internal screw-thread which corresponds to the external thread of the MC600 with the dimensions M25x1.5. Simply screwed on, the screw thread is additionally sealed using a special screw thread protection, so that oils, dirt and other liquids cannot penetrate the assembly. With the ACE protective shroud, the impact energy is securely absorbed by an impact head integrated into the end face, and it transfers this energy into the damper. The head is produced from stainless steel, material ref: 1.4404, and has already successfully proved its operational reliability in customer field trials as has the entirely new accessory from Langenfeld. As a stainless steel version of the MC600 ACE damper is also available, the shroud is also exceptionally suited for use in medical technology and food industry sectors. Based on positive feed-back in field tests, ACE will soon launch the Types PF20 and PF14 in the thread sizes M14x1.5 and M20x1.5. Therefore even more design engineers can profit in future from sealing systems providing optimal protection. If miniature and industrial shock absorbers are employed in aggressive environments without protective shrouds, operators run the risk of having to frequently replace them. As well as the costs for the machine element and for the replacement parts, unproductive down-time can also result. Not infrequently failure results in damage to the machines which are actually being protected. Whoever uses the new protective shroud, which is supplied by ACE ready assembled with the corresponding shock absorber, is ensuring total security. And the protective shroud, which is manufactured from PTFE, repays any small capital expenditure after a very short time.