Chapter 1 Flashcards
(24 cards)
Hydraulics
Hydra means water, uses water or oil
Pneumatics
Pneu means air, uses air
Work
Work= force x distance Unit= Nm or ftlb
ANSI
American national standard institute
1 ton
=2000 lbs
Pascal’s law
Pressure is distributed equally in all directions in a non flowing system
Actuators
Something that does work, ex: double acting cylinders
Ports
There are two ports on the double acting cylinder, they are where fluid enters and exits
Blind end side
The left hand side, has the most area, the diameter of the blind end side is called a bore
Effective area
Area of the blind end side minus the area of the rod end side
Extension/retraction
E - fluid comes in through blind and exits through rod
R - fluid comes in through rod and exists through blind
Dead heading
When cylinder is fully extended or fully retracted
3 types of valves
Directional, flow control, and pressure control
Relief valve
- Is a pressure control valve, pilot line allows pressure to enter with no flow
- protects the circuit, keeps the pressure down
Suction hose velocity recommended
2 ft/s
Pressure line velocity recommended
15 ft/s
Sizing of conductors
- hoses, piping, & tubing
- laminar flow is desired
Force and torque
Pressure determine force and torque
Velocity and RPM
GPM determines velocity and RPM
fluid power circuit
has three features: conversion from mechanical to fluid energy, delivery, and conversion from fluid back to mechanical energy
pump
develops flow of fluid through the circuit
directional control valve
directs the flow of fluid based on its position
cylinder
linear actuator, converts hydraulic energy into a force acting over some distance
advantages of fluid power
high power density, control, and not damaged when overloaded
