Term
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Definition
| power is transmitted thru a high pressure flow of air & fluid |
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Term
| Why is fluid power engineering so convenient? |
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Definition
| fast response, accurate control, smooth application of force, scalable |
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Term
| What are the pros and cons of an electric motor? |
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Definition
| lighter, takes longer to run, results in less power |
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Term
| What are the pros and cons of an hydraulic motor? |
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Definition
| higher power, less run time, heavier |
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Term
| Fluid power accounts for ___ percent of total US energy consumption. |
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Definition
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Term
| Where do most fluid power engines get their energy from? |
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Definition
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Term
| The average mobile fluid power system efficiency is _____ percent. |
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Definition
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Term
| An increase in system efficiency by 5% would save the US ____ to ___ billion per year. |
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Definition
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Term
| An increase in system efficiency by 5% would reduce ____ million tubs of CO2 a year. |
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Definition
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Term
| Fluid power is a ___ billion dollar industry in the US. |
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Definition
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Term
| What are some applications of fluid power? |
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Definition
| automotive (car lifts), agriculture (tractors), entertainment (drop rides), medical, green energy, aerospace |
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Term
| Fluid power has ______ power density. |
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Definition
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Term
| Why does fluid power have so many applications? |
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Definition
| it can harness and store energy that other kinds of technologies cannot |
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Term
| What was the earliest description of a pump? |
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Definition
| described by Archimedes around 300 BC, known as the Archimedes screw pump, used mechanical forces to push material by physically lifting or by compression force |
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Term
| Who patented the hydrostatic machine in 1785? |
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Definition
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Term
| Who patented the hydraulic press in 1795? |
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Definition
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Term
| How did the water pumping windmill work? |
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Definition
| allowed farming and ranching (contributing to the rail system expansion) by pumping water from wells to supply the needs of farms and steam locomotives |
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Term
| When did oil hydraulic systems reach full potential? |
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Definition
| After WW2, when the swash plate design was developed and the electro hydraulic servo valve was introduced |
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Term
| When was the first oil hydraulic system introduced? |
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Definition
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Term
| What are the cons of using water in a hydraulic system? |
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Definition
| can boil or freeze, rusts the system |
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Term
| What are the pros of using oil in a hydraulic system? |
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Definition
| the density/ viscosity can be varied, not sensitive to temperature, acts as a lubricant |
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Term
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Definition
| father of fluid power, 1907-1999, held 19 patents, developed the hi-power riveter, showed at the 1935 Cleveland machine tool show |
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Term
| Why was Maha's hi-power riveter so important? |
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Definition
| revolutionized how hydraulics were utilized in manufacturing assemblies |
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Term
| What are the units of pressure? |
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Definition
| psi (pounds per square inch) |
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Term
| What is atmospheric pressure? |
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Definition
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Term
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Definition
| measured pressure relative to atmospheric pressure |
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Term
| What is absolute pressure? |
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Definition
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Term
| What is negative pressure |
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Definition
| when pressure is 0, or a vacuum |
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Term
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Definition
| for every increase in pressure in a fluid, there is an equal increase in the fluid at every other point in the container |
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Term
| What are the three methods of transmitting power? |
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Definition
| electrical, mechanical, fluid power |
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Term
| What are the advantages of fluid power? |
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Definition
| ease and accuracy of control, multiplication of force (can easily multiply from an ounce to hundreds of tons), constant force regardless of speed changes, fewer moving parts, more safe, more economics |
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Term
| What are the drawbacks of fluid power? |
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Definition
| oil is messy, leakage, lines can burst, prolonged exposure to loud noises, fire risk |
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Term
| What are the main three components of a hydraulic system? |
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Definition
| cylinder (actuator), pump, valve |
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Term
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Definition
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Term
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Definition
| force liquid through the system |
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Term
| What does a power source do? |
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Definition
| provide energy to drive pump (prime mover) |
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Term
| What does an actuator do? |
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Definition
| converts fluid energy to linear motion |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
| directional control valve |
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Term
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Definition
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Term
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Definition
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Term
| What are the pros and cons of a pneumatic system? |
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Definition
| less expensive to build and operate, less environmental effects, can store some energy, fire resistant, air is more compressible than liquids, less accurate, dangerous at high pressure ( > 250 psi), corrosive |
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Term
| What are the functions of fluid in a hydraulic system? |
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Definition
| transmit power, lubricate surfaces, dissipate heat, seal gaps |
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Term
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Definition
| have good lubricity, have good viscosity, chemically stable, compatible with system, incompressible, fire resistant, low density, foam resistant, non toxic, low volatility, carry away contaminants |
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Term
| What are signs a fluid should be changed? |
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Definition
| color change (increased acidity), lubricity (polymerization and additive breakdown), foaming |
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Term
| What should fluids be tested for? |
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Definition
| viscosity, water content, foreign object contamination |
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Term
| What is the effective bulk modulus? |
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Definition
| represents the real bulk modulus of oil with consideration of vapor and trapped air |
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Term
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Definition
| the springiness of a fluid |
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Term
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Definition
| resistance to deformation by applied stress |
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