Power and Propulsion

Hydraulic systems

Stories

124
3186
0
30
30
Articles: Motion Control
Performing closed-loop control of hydraulic servo systems is often more challenging than controlling servomotor systems. The main reason is that hydraulic systems use compressible oil to move...
Feature Image
Briefs: Software
Gaseous Nitrogen Orifice Mass Flow Calculator
The Gaseous Nitrogen (GN2) Orifice Mass Flow Calculator was used to determine Space Shuttle Orbiter Water Spray Boiler (WSB) GN2 high-pressure tank source depletion rates for various leak scenarios, and the ability of the GN2 consumables to support cooling of Auxiliary Power Unit (APU) lubrication...
Briefs: Materials
Bonding to aluminum can be a difficult task. Many engineers will search for a single and simple remedy in the form of a low-temperature adhesive for making structural joints without welding. A...
Feature Image
Application Briefs: Motion Control
Manufacturers often need to test their products to verify that they meet customer specifications, and provide the data that verifies specification compliance. This is particularly true...
Feature Image
Application Briefs: Robotics, Automation & Control
The manufacturing of pharmaceutical tablets is carried out using machines that appear, at first sight, to be very simple. First, a die is filled with the correct amount...
Feature Image
Articles: Robotics, Automation & Control
Hydraulic steering systems have long dominated the industrial utility vehicle market because of their familiarity both to vehicle designers and...
Feature Image
Application Briefs: Robotics, Automation & Control
How do you test the behavior of different soil structures in an earthquake? Obviously, large earthquakes don’t happen often, and they certainly don’t happen on cue. The solution,...
Feature Image
Briefs: Physical Sciences
Method to Estimate the Dissolved Air Content in Hydraulic Fluid
In order to verify the air content in hydraulic fluid, an instrument was needed to measure the dissolved air content before the fluid was loaded into the system. The instrument also needed to measure the dissolved air content in situ and in real time during the de-aeration process. The...
Briefs: Physical Sciences
Use of Dynamic Distortion to Predict and Alleviate Loss of Control
This research has developed and evaluated the specific concepts, termed “Smart-Cue” and “Smart-Gain,” to alleviate aircraft loss of control that results from unfavorable pilot/vehicle system interactions, including pilot-induced oscillations (PIOs). Unfavorable pilot/...
Briefs: Unmanned Systems
An ocean thermal energy conversion (OTEC), now undergoing development, is a less-massive, more-efficient means of exploiting the same basic principle as that of the proposed system described in...
Feature Image
Briefs: Energy
A proposed scheme for generating electric power from rivers and from ocean currents, tides, and waves is intended to offer economic and environmental advantages over prior such...
Feature Image
Articles: Motion Control
Electric Actuators Deliver Energy Efficient, Low Maintenance Solutions
Machine designers and end users find themselves balancing sometimes opposing priorities such as improving energy efficiency while minimizing adverse impact on the environment, at the same time ensuring performance (e.g., precision, reliability) is not compromised. A key trend...
Briefs: Materials
A proposed system for exploiting the ocean thermal gradient to generate power would be based on the thawing-expansion/ freezing-contraction behavior of a wax or perhaps another suitable phase-change...
Feature Image
Briefs: Mechanical & Fluid Systems
Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated....
Feature Image
Articles: Robotics, Automation & Control
The trend in aircraft design is toward more efficient brushless DC motors. A integrated motor drive module for brushless DC motors from International Rectifier (El Segundo, CA) reduces the effort of...
Feature Image
Briefs: Photonics/Optics
The use of piezoelectric devices has become widespread since Pierre and Jacques Curie discovered the piezoelectric effect in 1880. Examples of current applications of piezoelectric devices...
Feature Image
Application Briefs: Motion Control
Tractair Ltd., based in Brough, UK, designs, manufactures and installs air and hydraulic brake systems for special applications. The company works closely with the design engineers of major...
Feature Image
Articles: Robotics, Automation & Control
Robotic system designers should choose the right power source for the job. Often, electric motors are chosen without thinking about the benefits of hydraulics or...
Feature Image
Briefs: Test & Measurement
A desk-sized apparatus for testing monoball bearings and their lubricants offers advantages, relative to prior such apparatuses, of (1) a greater degree of automation and (2) capability of...
Feature Image
Briefs: Mechanical & Fluid Systems
A proposed three degree of freedom (tilt/tip/piston) manipulator, suitable for aligning an optical or mechanical component, would offer several advantages over prior such manipulators:
Feature Image
Briefs: Mechanical & Fluid Systems
Controllable active struts that would function as linear actuators with variable spring stiffness and damping have been proposed as components of advanced suspension systems of future...
Feature Image
Briefs: Robotics, Automation & Control
A product line of improved electrohydraulic linear actuators has been developed. These actuators are designed especially for use in actuating valves in rocket-engine test facilities. They are also...
Feature Image
Briefs: Information Technology
An automatic method to schedule maintenance and repair of complex systems is produced based on a computational structure called the Informed Maintenance Grid (IMG). This method provides solutions to...
Feature Image
Briefs: Mechanical & Fluid Systems
An improved linear dynamometer has been developed for testing linear alternators that are to be used to convert mechanical power to electrical power in free-piston Stirlingcycle engines....
Feature Image
Briefs: Physical Sciences
Magnetostrictive Valves Actuated by Flux Tubes
Magnetostrictive valves for cryogenic applications would be actuated by superconducting flux tubes (SFTs), according to a proposal. The reasoning behind this proposal closely tracks that of the proposal to use SFTs in magnetostrictive heat switches, as reported in the preceding article.
Briefs: Test & Measurement
An improved solvent-extraction/infrared-analysis technique has been devised to replace an older technique for measuring very small concentrations of nonvolatile residues of industrial...
Feature Image
Briefs: Motion Control
Hydraulically Driven High-Speed Spindle for General Machining
A hydraulically driven high-speed spindle system for milling, machining, facing, drilling, and joining metallic and nonmetallic materials has been developed. Spindles are the most critical elements of high-speed milling machines. The keys to successful design of high-speed spindles are...

Videos