Engineering Basics

Positive-displacement pumps, also called hydrostatic pumps, are used in fluid power motion control applications. They have a very small clearance between rotating and stationary parts. These pumps deliver a specific amount of fluid to the system for each revolution. Positive-displacement pumps can be further divided into two categories: Fixed- and variable-displacement. Fixed-delivery pumps provide a […]

This article was updated on July 15, 2016, with new images. A hydraulic manifold is a component that regulates fluid flow between pumps and actuators and other components in a hydraulic system. It could be compared to a switchboard in an electrical circuit, because it lets the operator control how much fluid flows between components of a hydraulic machinery. For example, in a backhoe […]

Improper selection or improper use of hoses, tubing, fittings, and assemblies can cause failures, personal injury, or property damage. Understanding the hose assembly and following the installation instructions provided by manufacturers will reduce these risks. Engineers looking to specify hose couplings need to consider a few things besides correct size. Will the couplings be reused […]

Cylinders allow hydraulic systems to apply linear motion and force without mechanical gears or levers by transferring the pressure from fluid through a piston to the point of operation. Hydraulic cylinders are at work in both industrial applications (hydraulic presses, cranes, forges, packing machines), and mobile applications (agricultural machines, construction equipment, marine equipment). And, when […]

A hydraulic hose is specifically designed to convey hydraulic fluid to or among hydraulic components, valves, actuators, and tools. It is typically flexible, often reinforced, and usually constructed with several layers of reinforcement since hydraulic systems frequently operate at high or very high pressures. Hydraulic hose is used in a variety of industrial hydraulic systems. […]

Hydraulic fittings connect tubes, pipes, or hoses to components (pumps, valves, cylinders, and so on) or together to create a system through which hydraulic fluid can flow without leaking. Fittings are meant to withstand high pressures and be leak resistant. Fitting variations allow designers to change the direction of flow, split flows, and change the […]

Filtration systems, commonly referred to as filter carts, are used for the external filtration of hydraulic fluids. These components are helpful for systems that may not need constant filtration, but only require it on occasion. They may also be used prior to the introduction of new hydraulic fluid into a system. The function of these […]

Many fluid power systems fail simply because there is too much contamination in the medium. In fact, some estimate that 75% of all fluid power failures can be attributed to contamination issues. There are multiple reasons why fluid can become contaminated. Use and wear of the components, poor plumbing, and contamination brought in with new […]

A clutch is a device used to transmit power from a driving member (motor/engine) to a subsequent one. As opposed to a mechanical clutch, a hydraulic clutch uses a fluid coupling device to transmit rotational power at variable operating speeds and without problems of shock loading. The fluid coupling device contains a driving turbine or […]

Accumulators are pressure vessels that store hydraulic energy and deliver that energy back to the system on demand. This is analogous to the way a car battery stores energy. In hydro-pneumatic accumulators, compressible gas (nitrogen) is used to keep stored fluid pressurized. Hydro-pneumatic accumulators are used extensively in the global fluid power industry. In process […]