Spring Characteristics and Force Tolerances of Gas Springs9139815
Contrary to almost every other type of springs, gas spring mounting bracket have a built in pretension force plus a flat spring characteristic. Which means there's merely a small improvement in force between full extension and full compression.
Because 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 usually around 30% at full compression.
The pushing spring movement is slow and controlled. It's reliant on the gas flow involving the piston sides being permitted to move through channels inside the piston during the stroke. Conventional gas springs use 'hydraulic damping', which involves a modest amount of oil reducing the speed of the stroke immediately ahead of the spring reaches full extension. Thus giving the movement a braking character at the conclusion position provided the piston rod is incorporated in the downward direction.
Force tolerances when charging with gas and other factors signify there may be variations within the force exerted by gas springs with the same nominal value.
The nominal values apply at 20° C, which is the temperature where gas charging is completed. Note that if the ambient temperature rises or falls, the force from the spring rises or falls depending on pressure changes in the cylinder. Generally of thumb, gas spring force increases by approximately 3.5% per 10° C temperature increase and reduces accordingly once the temperature falls.