What is hydraulic cylinder used for?
Hydraulic cylinders are used basically in all kinds of applications where a great amount of force is needed. For example, at Hydroline we manufacture hydraulic cylinders for agriculture, mining, construction, forestry and vehicles.
In agricultural segment hydraulic cylinders are used for example in lifting, suspension and load handling. In mining and construction segments typical applications are drilling machines, concrete sprayers and excavators. Forestry and vehicle applications use hydraulic cylinders in booms, lifts, steering and harvester heads in general. Hydraulic cylinders can also be found in aerial platforms as well as in factory environment, for example in paper machines.
Hydraulic cylinders are commonly used in places where heavy loads need to be moved and this requires a great amount of force. As an example, a tractor’s front hoist which needs to lift a heavy FIBC. Hydraulic cylinders are designed for specific purpose. Hydraulic cylinder’s strength is calculated a little bit over of the use that they are designed operate. This is called safety factor. Safety factor to secure there is no failure even if a heavier load is lifted. The safety factor is usually a little bit bigger for solutions where a risk for an accident is higher, such as aerial platforms.
First things to do when starting new design project is to research cylinders working environment. For example, in a factory environment there are rarely surprises and cylinders are usually not misused. When the cylinders are in for example tractors, the risk of misuse is higher as there are multiple users and they all use the tractor vehicle in different ways. What also needs to be considered is that how many cycles the cylinder operates during its daily use; does the cylinder need to work constantly during the day or just occasionally. Also, the pressure variation is one factor. In steady work the pressure rises and lowers smoothly but in irregular work cycle the pressure variation might be massive. For example, in forestry machine the pressure variation might be big large because the environment is variable and it might cause pressure peaks to hydraulic cylinder due to stumps and fallen trees. The pressure variations make an impact for hydraulic cylinders’ fatigue life. If the work is even light and steady, and the cycles count is small the designed fatigue life is a lot smaller than in cylinders that are constantly in use and face pressure peaks.
When it comes to designing hydraulic cylinders to various environments one have to remember that some cylinders are designed to take last 50 000 cycles as others are designed to last a million cycles. It depends on the customers specification what the cylinder’s lifetime need to be.
As an example of a really big large cylinder we could mention a cylinder at the base of a big large crane. This cylinder carries the weight of the whole boom structure and its payload. As an example of a really small cylinder there is a cylinder that presses the dimension indicator meter of a harvester head against the timber as the meter measures the length of the wood. It is a tiny cylinder that does not require a big amount of force but is necessary for the harvester to do its work job.