Spring Characteristics and Force Tolerances of Gas Springs9717148
In contrast to almost every other type of springs, gas spring ball stud possess a built in pretension force plus a flat spring characteristic. Which means there's just a small alteration in force between full extension and full compression.
As the piston and piston rod are pressed into the cylinder, volume reduces and pressure increases. This makes pushing force to boost. In conventional gas-type springs, this increase is generally around 30% at full compression.
The pushing spring movement is slow and controlled. It is reliant on the gas flow between the piston sides being permitted to pass through channels in the piston during the stroke. Conventional gas springs use 'hydraulic damping', involving a modest amount of oil slowing the speed from the stroke immediately ahead of the spring reaches full extension. This provides the movement a braking character by the end position so long as the piston rod is in the downward direction.
Force tolerances when charging with gas and other factors mean that there could be variations in the force exerted by gas springs with the same nominal value.
The nominal values apply at 20° C, the temperature of which gas charging is carried out. Remember that in the event the ambient temperature rises or falls, the force with the spring rises or falls according to pressure modifications in the cylinder. Generally of thumb, gas spring force increases by approximately 3.5% per 10° C temperature increase and reduces accordingly if the temperature falls.