Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
final fluid
| Question | Answer |
|---|---|
| limited rotation motors | provide output motion over a finite angle |
| limited rotation actuator | 1. rotary output over a finite angle 2. high instantaneous torque 3. torque capacity |
| hydraulic motors def | can rotate continuously and have same basic configuration as pumps |
| hydraulic motor examples | gear motor, vane motor, piston motors (inline/axial) |
| _____ requires _____ torque than it theoretically should | pump, greater |
| ______ outputs _____ torque than it theoretically should, due to frictional losses | motor, less |
| hydraulic transmission | system consisting of hydraulic pump, hydraulic motor, and valves & pipes must have prime mover like an electric motor |
| hydraulic transmission advantages | 1. infinitley variable speed and torque 2. bi directional 3. high hp to weight ratio 4. can stall without damage 5. low inertia of rotating members 6. flexibility & simplicity of design |
| valves | mechanical devices that control flow in any gas or liquid system |
| valve primary control functions | 1. start, stop, and direct flow 2. regulate or throttle flow 3. prevent backflow 4. regulate pressure 5. prevent excessive pressure |
| valve elements (3) | movable elements to obstruct or open flow Ball, poppet, spool |
| Directional control valves | provide the means by which fluid energy is transmitted to various parts of the system |
| DCV functions (7) | 1. Activate or close a circuit 2. reverse direction of flow 3. isolate circuit branches 4. divert or divide flow 5. deactivate a circuit 6. combine flow streams 7. redirect flow from 1 branch to other branches |
| Valve symbols (3) | basic building blocks for preparing circuit drawings pictorial, cutaway, graphical |
| DCV widely used descriptive terms | way, position, port |
| DCV symbol letter P | pump or pressure port |
| DCV symbol letter T | tank or reservoir port |
| DCV symbol letter x/y | pilot pressure ports |
| DCV symbol letter V | vent port |
| DCV symbol letter D | drain port |
| DCV symbol letter A/B | actuators, work, or motor ports |
| fluid power advantages | 1. ease and accuracy of control 2. multiplication of force 3. constant force or torque (constant regardless of speed changes) 4. simplicity, safety, economy (fewer moving parts) |
| fluid power disadvantages | 1. oils are messy 2. leakage 3. lines can burst 4. prolonged exposure to loud noises 5. fire |
| hydraulic system 3 main components | valve, pump, cylinder |
| actuators | convert fluid energy |
| hydraulic system components | Tank (Reservoir) Pump to force liquid through the system Power source to drive pump (prime mover) Actuators to convert fluid energy Valves to control fluid Piping |
| pneumatic system components | air tank to store compressed air compressor electric motor to drive compressor valves to control air actuators to convert fluid power piping |
| hydraulic advantage | very accurate and precise |
| liquids | very rigid medium, nearly incompressible, volume doesn't change much w/ pressure |
| air/gasses | spongy due to compressibility of air very compressible, volume decreases as pressure increases |
| pneumatic | less expensive to build and operate |
| fluids | liquids and gasses |
| air advantages | fire resistant not messy environmentally friendly inexpensive can store some energy |
| air disadvantages | can't be used where accurate positioning or rigid holding is required sluggish corrosive-water and oxygen doesn't self lube dangerous at high pressure |
| most important part of hydraulic or pneumatic system | fluid/ medium |
| fluid 4 basic functions | transmit power, lube surfaces, dissipate heat, seal gaps |
| fluids tests for when to replace | 1. increased acidity(color change) 2. polymerization and additive breakdown (lubricity) 3. foaming test for viscosity, water content, foreign object contamination |
| hydraulic system | energy transfer system |
| hydraulic versality | variable speed reversibility overload protection high hp to weight immunity to damage under stalled conditions |
| 1. newtons first law 2. newtons second law 3. newtons third law | 1. a force is required to change motion of a body 2. acceleration of body is promotional to magnitude of force and inversely proportional to mass 3. equal and opposite forces between bodies |
| Pascals law | Pressure applied to a confined fluid is transmitted undiminished in all directions |
| steady flow pipeline | weight flow is the same for all cross sections of a pipe |
| motor | converts hydraulic energy into mechanical energy |
| displacement | volume of fluid delivered per revolution of the pump shaft rotation |
| cavitation | when pressure in a chamber is lowered below vapor pressure of fluid which causes bubbles that rapidly collapse at high pressure |
| 3 most important hydraulic system components | valve pump and cylinder |
| actuator | used to store fluid 1. meet peak demands of power 2. smooth out pressure surges 3. provide emergency power sources |
Created by:
user-1742075