Functioning of gas springs

The gas spring is a hydropneumatic adjustment element consisting of a cylinder, piston rod and specific piston. A special sealing and guiding system seals the cylinder. The gas spring is filled with nitrogen.

Compared to a traditional (coil) spring, the gas spring has a very flat curve. We can achieve this flat curve even with very large stroke. This unique feature is crucial in any situation where a weight needs to be balanced or moved. The force of the gas spring is determined by the difference in surface area on both sides of the piston.

This is how our Brimotech gas springs work

In its simplest form, the gas spring consists of a cylinder (C) and a piston rod (S) to which the piston (P) is attached. When the piston rod with piston is pushed into the cylinder, the gas (nitrogen) will “flow” from chamber (B) through special channels into chamber (A). By adjusting these channels, the behavior of the gas spring (speeds, damping) can be tailored to the needs of the application. The pressure in both chambers (A & B) is equal, so the difference in area of the piston on side (A) and side (B) ensures that the piston rod will always be pushed out of the cylinder. This reaction provides the force of the gas spring.

Measuring the forces

Measuring the force(s) of our gas springs is done by special tools at room temperature with the cylinder pointing upward. All forces are measured in Newtons [N] and are static. For some relationships we give all values in [kg].

The force one communicates with and which should be on the gas spring we call the F1. This is the minimum force that the gas spring delivers. The relationship between F1 and F2 or F3 and F4 we call the progressivity. In short, the increase in force when the gas spring is depressed.

The difference between F1 and F3 as well as the difference between F2 and F4 is the friction. We can adjust both values (progressiveness and friction) on request to create the perfect gas spring for any situation.

Temperatures

The ambient temperature in which the gas spring is used affects the force it delivers. Normally all gas springs are filled and measured at room temperature of 20ºC. When the nitrogen in the gas spring warms up or cools down, the force of the gas spring will change. This change is equal to 3.4% per 10ºC. Our gas springs can be used as standard from -30ºC to +80ºC. On request, we can modify various components to meet other temperatures.