Hydraulics

Question 1

Pressure, force, area triangle

Answer 1

• force is weight usually lbs
• pressure is psi
• area is just that pie x d2 divided by 4

Question 2

Power supplies

Answer 2

-prime mover (electric motor) -pumps -reservoir

Question 3

Control Device

Answer 3

-directional -pressure control -flow control

Question 4

Output

Answer 4

-actuator (rotary/linear) -loads

Question 5

Pressure

Answer 5

• the force on a unit of area
• pressure decreases when flow is increased
• produced by resistance to flow

Question 6

Pascall’s Law

Answer 6

-relation between force, pressure & area -remember triangle

Question 7

Pressure creation

Answer 7

-resistance to flow -not a pump, pump creates flow

Question 8

Intensifiers

Answer 8

-contained fluid in two different areas in a cylinder -used to efficiently generate a high pressure fluid -output pressure is considerably greater than input pressure.

Question 9

Atmospheric Pressure

Answer 9

-how much weight is sitting on you right now from the air, etc… -14.7 psi at sea level

Question 10

Differential Cylinders

Answer 10

-cylinders with different areas on each side of piston -remember the area loss from the rod

Question 11

Non-differential cylinders

Answer 11

-areas on each side are the same -most two Rod cylinders

Question 12

Load Capacities

Answer 12

-the larger the area, the larger the force for the same pressure

Question 13

Extension

Answer 13

-on extension, the pressure acts on the area of the piston

Question 14

Retraction

Answer 14

-on retraction the pressure is the piston area minus the rod area (annulus area)

Question 15

Advantages of Hydraulics

Answer 15

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Question 16

Disadvantages of Hydraulics

Answer 16

-

Question 17

2 to 1 cylinder

Answer 17

-the cross section area of the rod occupies exactly half the area of the cap end side

Question 18

Flow

Answer 18

-movement of a liquid produced by a pump or a pressure drop across a hole -the greater the pressure difference across a hole the greater the flow -the ratio of units/time. It can be expresses as velocity (ft/min, ft/sec) -flow info a differential cylinder does not equal flow out

Question 19

Flow Triangle

Answer 19

• speed/flow/area relationship
• V/t or Q stands for flow in cubic inches/minutes only -S stands for the speed in inches/minutes
• A stands for the area in squares inches

Question 20

Hydraulic Intensifier Math Question

Answer 20

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Question 21

Hydraulic Cylinder Math

Answer 21

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Question 22

Porta Power Math

Answer 22

-Steps