Hydraulic machinery - WikipediaFluid power is the use of fluids under pressure to generate, control, and transmit power. Fluid power is subdivided into hydraulics using a liquid such as mineral oil or water , and pneumatics using a gas such as air or other gases. Compressed-air and water-pressure systems were once used to transmit power from a central source to industrial users over extended geographic areas; fluid power systems today are usually within a single building or mobile machine. Fluid power systems perform work by a pressurized fluid bearing directly on a piston in a cylinder or in a fluid motor. A fluid cylinder produces a force resulting in linear motion, whereas a fluid motor produces torque resulting in rotary motion.
Hydraulic machines use liquid fluid power to perform work. Heavy construction vehicles are a common example. In this type of machine, hydraulic fluid is pumped to various hydraulic motors and hydraulic cylinders throughout the machine and becomes pressurised according to the resistance present. A hydraulic system uses an incompressible liquid as its fluid, rather than a compressible gas. The popularity of hydraulic machinery is due to the very large amount of power that can be transferred through small tubes and flexible hoses, and the high power density and wide array of actuators that can make use of this power, and the huge multiplication of forces that can be achieved by applying pressures over relatively large areas. One drawback, compared to machines using gears and shafts, is that any transmission of power results in some losses due to resistance of fluid flow through the piping. Joseph Bramah patented the hydraulic press in
Hydraulic Power Generators Selection and specification of pumps, pump characteristics. Linear and Rotary Actuators selection, specification and characteristics. Pressure - direction and flow control valves - relief valves, non-return and safety valves - actuation systems. Reciprocation, quick return, sequencing, synchronizing circuits - accumulator circuits - industrial circuits - press circuits - hydraulic milling machine - grinding, planning, copying, - forklift, earth mover circuits- design and selection of components - safety and emergency mandrels. Pneumatic fundamentals - control elements, position and pressure sensing - logic circuits - switching circuits - fringe conditions modules and these integration sequential circuits - cascade methods - mapping methods - step counter method compound circuit design - combination circuit design. Pneumatic equipments- selection of components - design calculations application fault finding - hydro pneumatic circuits - use of microprocessors for sequencing PLC, Low cost automation - Robotic circuits.
Hydraulics and Pneumatics By Andrew Parr — Nearly all industrial processes require objects to be moved, manipulated or subjected to some sort of force. This is frequently accomplished by means of electrical equipment such as motors or solenoids , or via devices driven by air pneumatics or liquids hydraulics. This book has been written by a process control engineer as a guide to the operation of hydraulic and pneumatic systems for all engineers and technicians who wish to have an insight into the components and operation of such a system. This second edition has been fully updated to include all recent developments such as the increasing use of proportional valves, and includes an extra expanded section on industrial safety. It will prove indispensable to all those wishing to learn about hydraulics and pneumatics.