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  • Skydrol


    Skydrol is a fire-resistant aviation hydraulic fluid manufactured by Solutia (now part of Eastman Chemical Company), and formerly manufactured by Monsanto. There are various lines of Skydrol including Skydrol 500B-4, Skydrol LD-4, and Skydrol 5. Skydrol is made of a fire-resistant phosphate ester base stock, with a number of oil additives dissolved into it to inhibit corrosion and prevent erosion damage to servo valves. It also includes a purple or green dye to ease identification. It has been approved by most airframe manufacturers including Airbus, Boeing and BAE Systems and has been used in their products for over 40 years.

  • Recloser


    Four reclosers on the right side of a substation In electric power distribution, automatic circuit reclosers (ACRs) are a class of switchgear which is designed for use on overhead electricity distribution networks to detect and interrupt momentary faults. Also known as Reclosers or Autoreclosers, ACRs are essentially high voltage rated circuit breakers with integrated current and voltage sensors and a protection relay, optimized for use as an overhead network distribution protection asset. Commercial ACRs are governed by the ANSI/IEEE C37.60, IEC 62271-111 and IEC 62271-200 standards. The three major classes of operating voltage are 15.5 kV, 27 kV and 38 kV. For overhead distribution networks, the majority of faults are transient, such as lightning strike, surges or foreign objects coming into contact with the exposed distribution lines. By this logic, 80% of outages can be resolved by a simple close operation. Reclosers are designed to handle a short close-open duty cycle, where electrical engineers can optionally configure the number of attempted close operations prior to transitioning to a lockout stage. Reclosers were invented in the mid 1900s in the USA. Some of the earliest reclosers were introduced by Kyle Corporation (which was acquired by Cooper Power Systems - part of the Eaton family) in the early 1940s. The brand was the industry leader in reclosers, sectionalizers and switchgear until the 2000s when many other manufacturers entered the market. Reclosers were originally oil filled hydraulic devices with rudimentary mechanical protection relaying capabilities. Modern Automatic Circuit Reclosers are significantly more advanced than the original hydraulic units. The advent of semiconductor based electronic protective relays in the 1980s resulted in increased sophistication, allowing for differing responses to the various cases of abnormal operation or fault on a distribution networks. The high voltage insulation and interrupting device in modern reclosers typically consist of Solid Dielectric Insulation with vacuum interrupters for current interruption and arc quenching. Reclosers are often used as a key component in a smart grid, as they are effectively computer controlled switchgear which can be remotely operated and interrogated using SCADA or other communications. This capability allows utilities to aggregate data about their network performance, and develop automation schemes for power restoration. This automation can either be distributed (executed at the remote recloser level) or centralized (close and open commands issued by a central control room to be executed by remotely controlled ACRs).

  • Gerotor


    A Gerotor, image does not show intake/exhaust A gerotor is a positive displacement pump. The name gerotor is derived from "Generated Rotor". A gerotor unit consists of an inner and outer rotor. The inner rotor has n teeth, while the outer rotor has n+ 1 teeth; with n defined as a natural number greater than 2. The axis of the inner rotor is offset from the axis of the outer rotor and both rotors rotate on their respective axes. The geometry of the two rotors partitions the volume between them into n different dynamically-changing volumes. During the assembly's rotation cycle, each of these volumes changes continuously, so any given volume first increases, and then decreases. An increase creates a vacuum. This vacuum creates suction, and hence, this part of the cycle is where the intake is located. As a volume decreases compression occurs. During this compression period, fluids can be pumped, or, if they are gaseous fluids, compressed. Gerotor pumps are generally designed using a trochoidal inner rotor and an outer rotor formed by a circle with intersecting circular arcs. A gerotor can also function as a pistonless rotary engine. High pressure gas enters the intake area and pushes against the inner and outer rotors, causing both to rotate as the area between the inner and outer rotor increases. During the compression period, the exhaust is pumped out.

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