The Basics to Hydraulic Cylinders

The Basics to Hydraulic Cylinders

At first glance hydraulic cylinders appear straight forward, but once you start to have a closer look at what’s underneath it can become a little more confusing. Cylinders come in all different shapes and sizes, from trailer cylinders to hydraulics actuators. With different functions for different styles, it’s important to fully understand the basic functions to these hydraulic cylinders.


Today we’ll be diving into the basic functions and knowledge needed to develop a full grasp on all hydraulic cylinders.


Linear Motion

A hydraulic ram kit cylinder uses high pressure oil to move pressure into motion within its system. The motion created through this pressure is guided by two linear surfaces, these bearing surfaces support the piston or rod in the tube head. Many of these systems are used across a common range of cylinder constructions, depending entirely on the technical and economic needs of the particular system you’re working with.


After finding out the specific hydraulic system that you’re working with you should factor in the operating speed, side loading, life expectancy and the requirements and cost of the manufacture to find out exactly what you’re working with and the specific elements you’ll have to ensure that it works in the highest efficiency possible.


Pressure Containment

The high level of pressure that’s used to enforce linear motion in your cylinder has to be safely contained within the cylinder tube in order to function correctly and extend its life expectancy. The pressure is contained through the joints used in the cylinder’s tubular construction. The construction of these joints entails a system that is statically sealed with permanent welded joints or that have been mechanically assembled. As well as being dynamically sealed, which allows the sliding motion that continues to contain the fluid’s pressure that generates motion.



Now that there’s some motion and force being crested within your hydraulic cylinder, we need to consider how to use this movement in the use of machines. To be able to correctly use this in a machine you’ll need to mount the cylinder so that the desired movement and reliable operation can be applied. By mounting the cylinder in this correct way, you can ensure a reliable and smooth function of your system in the operation of your machine.


To find this correct and reliable mounting position you’ll need to take note of the linear device and load that these systems exert. You’ll want to ensure that this exertion can act alongside the central axis of the cylinders bore, taking the extra time to make sure this integration you’re creating is mounted correctly to minimise the wear and tear your system will be faced with.


Some common forms of cylinder mounting that will ensure the correct placement and extended life of your system include fixed clevis, which allows the flexing of one plane, this is the most common and cost affection solution used. You can also complete this by trunnion, allowing the flexing of one plane, spherical, creating self-alignment in the cylinders action points and flange, which entails fixing the cylinders body to the machine’s frame. While deciding on one of these methods for the mounting of your system you should always consider the required motion of the machine and its strength, symmetry, and stiffness.


Connection and Control

Manual and electronic controlled valves direct pressure to your cylinder through pipes to create the movement and force that you’ve set and require for the function of your system. The overall design of your chosen system is the most essential element to be aware of, as it can affect the safety and effectiveness of your system’s function. Integrated load control and relief valves are another important aspect to choose as they can protect your machine, operators and the movement of your machine.


Hopefully this brief guide has helped to understand the basic running and considerations needed for your hydraulics system. If you still have questions or are unsure of the considerations, you need for your cylinder or want to find the best system to suit your needs contact us today or browse our range of hydraulic cylinders online at Motus Hydraulics.


Hartley Currie – General Manager

Bob Kerins – Sales & Marketing

Ryan Carrol – Sales