2nd Half Second Semester

Question 1

Gerotor

Answer 1

black ring around motor

Wider gerotor, more surface area, more torque

Question 2

Function of Oil

Answer 2

Transmits energy/power

Question 3

Double Acting Cylinder

Answer 3

2 directions

Question 4

Reservoir Purposes

Answer 4

• Hold oil
• helps cool the oil
• places for extra oil to go
• allows oil to rest, foreign matter in oil allowed to sink to bottom of reservoir

Question 5

Advantages of Hydraulics

Answer 5

1. Variable Speed
2. Very Easily Reversible
3. Overload (easy to avoid, won’t even try)
4. Usually components are smaller, size matters
5. Can be stalled without hurting anything
6. Quiet (the actuator) - can separate loud vs. quiet parts

Question 6

Cubic inches of a gallon (magic number)

Answer 6

231 cubic inches of a gallon

Question 7

How determine torque in rotary actuator?

Answer 7

Torque determined by pressure & area oil is pushing -load on motor determines pressure because it’s resisting flow of oil into actuator -area & psi tell torque = load

Question 8

0.0007 assumes?

Answer 8

80%

Question 9

Reducing coupling

Answer 9

up

Converts smaller to bigger pipe

Question 10

Proportional Valve

Answer 10

Electrical directional control that can control flow, can move spool cooly under control

Question 11

Every system should have a _____

Answer 11

Filter

Question 12

Union

Answer 12

Can move sections of pipe without twisting pipe

Question 13

What does gauge read in Tandem Center?

Answer 13

Zero

Question 14

Cavitation

Answer 14

not getting enough fluid for what the pump wants

Question 15

Symptoms that air might be in oil

Answer 15

Noisy, things don’t operate the way they should

Question 16

Why does cylinder slow @ end of stroke?

Answer 16

Air cushion

-Retract is faster because less area to push oil into when cylinder is extended

Question 17

How heavy is gallon of oil?

Answer 17

6#’s

Question 18

Precharge

Answer 18

when charging up accumulator

Question 19

What does flow control do?

Answer 19

Controls the speed of the actuator

Question 20

Which flow control method is preferred?

Answer 20

Meter Out

Don’t use bypass, will pull oil out because it’s the pass of least resistance

Question 21

Proper name of Tandem Center/all control valves

Answer 21

“4 way direction lever operated spring tandem center conrol valve”

Question 22

Figure out amps in system

Answer 22

746 watts/HP

flow gauge says 2 gpm @ 300psi 2gpm*300psi*0.0007=0.42

0. 42*746=313.32
1. 32/120=2.6 amps

Question 23

What happens when we compress compressible fluid?

Answer 23

If compress 1/2, pressure will double

Nitrogen is compressible fluid, oil is not

Decrease volume by 1/2, pressure will double

Question 24

3 options for flow control

Answer 24

1. Meter In
2. Meter Out
3. Bypass

Question 25

Single Acting Cylinder

Answer 25

-Retract by a spring, gravity, a person, etc -forklift mast, pallet jack

Question 26

Why would pressure gauge differ from flow gauge?

Answer 26

Pres. Relief Valve is setting the pressure, some flow being diverted @ PRV, going back to tank, that's why pressure gauge

Question 27

Tubing is measured in \_\_\_\_\_\_

Answer 27

OD

Question 28

Another name for motor

Answer 28

Rotary Actuator

Question 29

Issue with motors in _SERIES_?

Answer 29

Different loads will cause motors to have different speeds Motor with lighter load will be driving system

Question 30

Pipe is measured in \_\_\_\_

Answer 30

ID

Question 31

Velocity

Answer 31

Displacement over time & a direction

Question 32

Pascal's Law

Answer 32

Pressure applied on a confined fluid is transmitted undiminished in all directions, and acts with equal force on equal areas and at right angels to them

Question 33

How pipe fits together

Answer 33

Pipe fittings threaded, leaking will happen - can use teflon tape to seal area off - threads on pipe are tapered a bit so more it goes in, tighter it gets

Question 34

Rods should be in \_\_\_\_\_

Answer 34

Tension Rods can buckle in compression

Question 35

What type of center with \>1 valve?

Answer 35

Closed center or power thru

Question 36

3 Types of Working Lines

Answer 36

1. Suction or Pump Inlet 2. Pressure 3. Return

Question 37

Accumulator Gas

Answer 37

use inert gas, Nitrogen

Question 38

How tubing fits together

Answer 38

metal to metal seals on surface, nut forces them together, no seal

Question 39

Drain Lines

Answer 39

-Short Dashes -takes supplemental leakage and puts it back into reservoir

Question 40

H-series motor Side Load

Answer 40

Perpendicular to shaft

Question 41

How to measure flow in system?

Answer 41

Flow Gauge

Question 42

Why don't we want 90-degree corner?

Answer 42

Because turbulent flow

Question 43

Pilot Lines

Answer 43

-Long Dashes -Transmits data (pressure) to pressure relief valve -always have one on the pressure line

Question 44

Control Valve Direction Cheat Sheet

Answer 44

First box: Up-down Third Box: Top Left to Bottom Right; TR-BL

Question 45

What type of Lever is hydraulics?

Answer 45

1st Class Lever

Question 46

3 Types of Lines

Answer 46

1. Working Lines 2. Pilot Lines 3. Drain Lines

Question 47

Energy Triangles

Answer 47

Determines which direction energy is going

Question 48

Accumulator

Answer 48

We use it for storage, overflow adds flow to the system Can add flow to system _for a period of time_

Question 49

H-series motor Thrust Load

Answer 49

Load parallel to shaft

Question 50

Stop Tubes

Answer 50

Put on inside to limit extend Put on outside to limit retract

Question 51

Extend vs. Retract Cylinder

Answer 51

Extend will have more force than retract

Question 52

Issue with motors in _PARALLEL?_

Answer 52

Wouldn't work, pressure would go to path of least resistance, motor with lightest load would run; heavier motor may not run - Could use this on wagon unit, connected together by floor gives it commonality - would put chain b/t motors so they can run together at same speed

Question 53

How heavy is gallon of water?

Answer 53

8#'s

Question 54

Tandem Center

Answer 54

Low system pressure due to no resistance of flow -keeps oil moving, pump to tank

Question 55

HP Actual Formula

Answer 55

GPM\*PSI\*0.0007

Question 56

Bang Bang

Answer 56

Solenoid operated control valve

Question 57

Reducing bushing

Answer 57

Down Converts bigger to smaller pipe

Question 58

Working Line Velocity

Answer 58

7-20 fps

Question 59

Check Valve

Answer 59

Free flow 1 way, control flow other way

Flow pushes ball against arrow, blocks

Put on both ends so it meters out

Question 60

3 places filter can go

Answer 60

1. _Before Pump_ * Not seen often as it restricts pump but good for filtering 2. _After Pump_ * Pro: Catches crap before it goes out in system * Con: must be designed to withstand pressure of system 3. _Going into Reservoir_ (end of system) * Pro: Doesn't restrict flow, really cheap * Con: worst possible position, crap has already flowed through system

Question 61

Pump Inlet Velocity

Answer 61

2-4 fps

Question 62

Directional valves we use have _____ ways

Answer 62

Four Ways

Question 63

Open Center

Answer 63

- Pressure is whatever it takes to get oil back to tank - Can have cylinder creep

Question 64

Aeration

Answer 64

Air in oil

Question 65

What type of valve is pressure relief valve?

Answer 65

Infinite Position valve

Question 66

HP theoretical formula?

Answer 66

(GPM\*PSI)/1714

Question 67

Directions in control valve

Answer 67

Left Box: P-A; B-T Right Box: (BL-TR) P-B (TL-BR) A-T

Question 68

3 Hydraulic Motors

Answer 68

1. Gear 2. Vane 3. Piston