Rotary actuators, in many cases, are a hybrid of linear and rotary actuators. Of course, in the fluid power realm, linear and rotary actuators are more affectionately referred to simply as cylinders and motors, respectively. A cylinder creates linear force when pressure acts up its piston’s surface area, while a motor creates rotational force when […]
Engineering Basics
How does hydraulic cylinder repair work?
By Josh Cosford, Contributing Editor When well cared for, hydraulic cylinders should last decades. So long as they were designed for their application — meaning they perform within the bounds of their environment — there should be no reason for damage or wear outside of regular use. The mount, rod and raw material should have […]
What are the most common hydraulic cylinder piston rod problems?
By Josh Cosford, Contributing Editor It would help if you never underestimate the importance of your cylinder rod. The rod is not just the object transmitting the force from the cylinder’s piston but also the interface between that cylinder and your machine. Before you can correctly select and then design the piston rod, you must […]
How do you safely precharge an accumulator?
By Josh Cosford, Contributing Editor When high-pressure hydraulics fail, the result is often a whimper as a seal blows out and pressure decays to useless levels. The harm to the surrounding environment and spectators is often little or none, which is why high-pressure hydraulic systems are so popular. However, when high-pressure pneumatic systems fail, you […]
What are flow control valves?
In the collection of hydraulic valve components, flow control valves are any device manufactured for the purpose of modifying the rate of fluid flow in a portion of a hydraulic circuit. Flow variability occurs through the adjustment of the effective orifice size inside the valve, and this is achieved through various techniques based upon the […]
How do relief valves work?
By Josh Cosford, Contributing Editor It seems like a question with an easy answer, but you’d be surprised how often people ask, “how do relief valves work?” We in the fluid power industry take our knowledge for granted, but each and every one of us was at some point ignorant of literally every hydraulic component […]
What is the difference between fixed and variable pumps?
For novices in the fluid power industry, lack of understanding between the fixed flow and variable flow pumping concepts is quite common. A hydraulic pump has one mission, and that is to transform incoming mechanical energy at its shaft into hydraulic energy capable of transferring force to actuators somewhere downstream. This transfer of force is […]
Telematics offers high-value solutions for industry
Telematics facilitates the exchange of rich data to and from mobile or remote machinery, helping to streamline maintenance and costs. Contributed by Carl Dyke, CD Industrial Group Inc. How can the owner of a fleet of cranes avoid the daily worries about whether the machines are being operated and maintained for safe performance? Is there […]
Hydraulic symbology 102: understanding basic fluid power schematics
By Josh Cosford, Contributing Editor Back in August of 2017, you saw my article Hydraulic symbology 101: Understanding basic fluid power schematics (read it here first, if you haven’t already). I covered basic constituent lines, shapes and their respective symbols. Due to space constraints, I left out some of the major components represented by symbols […]
How do I specify standard hydraulic manifolds?
By Josh Cosford, Contributing Editor The three most common ways to control hydraulic actuators are with lever valves, cartridge valves or sandwich valves. Lever valves are available as monoblock or stacked valves, and are primarily for directional control. Cartridge valves have nearly infinite possible combinations, but must be used with bodies or custom manifolds. Sandwich […]
