Fluid Power Lab

FLUID POWER LAB

Name Set: Date:

This lab will provide you with experiences and an understanding of: • Hydraulic Systems • Kinetic & Potential Energy • Pneumatic Systems • Mechanical Advantage • Cylinders • Friction • Pascal’s Law • Viscosity • Liquids & Gases • Work • Pressure

© TeacherGeek I nc. P erm ission g rant ed f or e dit ing annda pd prriinnttiinng tg to scchhoooollss,so liibbrraarriieesl, as annd nd noonn--pprrooffiittss.. M at erir ia l s f o r this a ct iivvi t y located here. Ad u llt st supervisionn r e q u i r eed fd foor cr ch i l d r een un un d eer 1r 12 . FLUID POWER LAB teachergeek supplies you’ll need Cut or find tubing the following lengths to use later in Activity Build Guides and Design & Engineering Challenges. Do not connect anything yet. First we’re going to experiment a bit with pressure.

Fluid Power Activity Pack/Maker Cart

tubing: 38mm (15in) 14ml cylinder 14ml cylinder

tubing: 38mm (15in) 4.5ml cylinder 14ml cylinder 4 - cylinder screws

Hydraulic Arm - Basic

tubing: 60cm (23in) 14ml cylinder 14ml cylinder

4.5ml cylinder 14ml cylinder tubing: 115cm (45in) 4 - cylinder screws

Hydraulic Arm - Advanced

4.5ml cylinder tubing: 100cm (40in) 14ml cylinder

tubing: 46cm (18in) 14ml cylinder 14ml cylinder 4 - cylinder screws

When it’s time, refer to the end of this lab for help assembling your pneumatic and hydraulic systems.

PNEUMATICS HYDRAULICS Pneumatic systems use a gas Hydraulic systems use a liquid to transmit and store power. to transmit power.

Hydraulic Pump, Compressor (Pump) Reservoir and Controls Hydraulic Cylinder Pneumatic Nail Gun

Hose (Pipeline)

Pneumatic Devices 1. List two devices, other than the ones above, that use pneumatics for operation. Describe how they use pneumatics.

Device How does it use pneumatics?

A Few Examples - air brakes on buses, trucks and trains; air compressors/pneumatic tooks; inflatable toys and bouncy castles; pipe organs; pneumatic air guns, nailers, sanders, grinders, wrenches, drills; pneumatic tires; jackhammer Hydraulic Devices 2. List two devices, other than the ones above, that use hydraulics for operation. Describe how they use hydraulics.

Device How does it use hydraulics?

A Few Examples - heavy equipment: backhoe, loader, forklift, crane, bulldozer, excavator; control surfaces on planes; car brakes; hydrostatic transmission; hydraulic robots

Fluid Port Fluid Port Piston A B Piston Rod Chambers and are sealed, Mount fluids can only enter or exit through A B the ports. Pressure in a chamber creates a force on the piston.

Cylinder Double-Acting Cylinders Most cylinders are double-acting. Double-acting cylinders allow pressurized fluid to flow on either side of the piston, allowing it to be powered in both directions.

Pressurized Fluid Fluid Pressurized Fluid In Out Out Fluid In

Outward Force Inward Movement

Single-Acting Cylinders Single-acting cylinders are only powered in one direction. The piston is returned by the weight of the load or a spring.

Pressurized Fluid Fluid In Out

Retracting Outward Force Gear Pump Gear

The pumps that power cylinders can usually only create a positive fluid pressure (push fluid). That is why most cylinders, like the ones shown above, are designed to only be powered by positive fluid pressure.

© TeacherGeek I nc. P erm ission g rant ed f or e dit ing annda pd prriinnttiinng tg to scchhoooollss,so liibbrraarriieesl, as annd nd noonn--pprrooffiittss.. M at erir ial s f o r t his a ct iivvi t y located here. Page 4 Ad u l tlt ssupervisionn r e q u i r eed fd foor cr ch i l d r een un un d eer 1r 12 . FLUID POWER LAB Your Cylinders Will Push & Pull You will use a cylinder as a pump. The cylinder will be able to push fluid (creating a positive pressure), or pull fluid (creating a negative pressure). This will allow your cylinders with a single port to be powered in both directions.

the correct answers below: Y Force In x Positive Z 1. There is a pressure in line Z . Negative

Force Out Pulling 2. Cylinder Y is fluid. x Pushing

Know Your Parts 3. Match the components with their name by placing letters into the boxes below. C Piston: C A C D Piston Rod: D

Cylinder: B B Fluid Port: A

fluid lines

cylinder Example TeacherGeek control panel Advanced Hydraulic Arm

what is pressure? 12lbs

Pressure is a force applied 2"

over an area: 3lbs 2" 1" 3lbs Force 1" 3lbs Pressure = 12lbs 3lbs Area 1in • 1in = 1in2 2in • 2in = 4in2 The area over which 12lbs 2 12lbs 2 the force is applied. = 12lbs/in = 3lbs/in 1in2 4in2

Less Area = More Pressure More Area = Less Pressure

Step One Step Two Push the piston end of a cylinder against your hand. Push the fluid port end of a cylinder against your hand.

Ouch!!!

FORCE FORCE

Area = .36in2 Area = .047in2

4. Both ends of the cylinder were pushed against your hand with the same force. Explain why they felt different? Hint: Pressure = Force/Area Step 1: The large piston end has a lot of area to spread (distribute) the force over, so the pressure is less. Step 2: The small end of the port does not have a lot of area to spread the force over, so the pressure is great.

Putting Your Foot Down 5. How much pressure does the cube A foot pushes down on a 3in3 apply to the ground? Show your work. cube with 45lbs of force. 45lbs Force 45lbs 2 Area of cube 5lbs/in touching the 2 = ground 9in 3" Answer: 2 3" 5lbs/in

Use this chart to find the formula find the unknown to calculate a missing variable (force, pressure, area). Let’s look at another way to write the formula: P = Pressure Force F Pressure = can be written as: F = Force Area P A A = Area

Cover the missing variable on the chart to find the formula to calculate it:

You know: Pressure, Area You know: Force, Area You know: Pressure, Force You need to find:Force You need to find: Pressure You need to find: Area

F F F P A P A P A

Force = Pressure • Area Pressure = Force/Area Area = Force / Pressure

6. Pressure transfers between the piston and the fluid in the cylinder. Calculate the force of the piston when the fluid applies 20lbs/in2 to it.

Show your work. 2 Piston Area = .27in F FORCE P A 4lbs = 4lbs Pressure 14.814psi ? 2 = Finger trapping .27in air in cylinder

Answer: 14.81 psi measurements of pressure lbs/in2 (psi) Pascal (Pa) 1 newton 1 Pound 1 Force = Force = Force A force of 1 pound A force of 1 newton

applied over an applied over an area area of 1 square inch = 1 psi of 1 square meter = 1 Pa produces a pressure produces a pressure 1 Inch2 1 Meter2 of 1 pound per of 1 pascal. square inch (1lb/in2) pounds per square inch Pascal can be can be abbreviated as “psi” abbreviated as "Pa"

Piston A applies pressure to the fluid inside chamber B . The fluid transmits the pressure in every direction and to every surface it touches.

FORCE B 7. If the pressure is 5psi in chamber , Squeezing a toothpaste tube what is the pressure in line C is an example of Pascal’s Law. and chamber D ? Squeezing applies external A pressure to the toothpaste fluid inside. The toothpaste transmits the force equally in all directions, pushing Answer: 5 psi D paste out and making B C the tube walls bulge.

Pressurizing Marshmallows

A Pull the piston out from the cylinder and place one small marshmallow inside the chamber.

B Push the piston in while covering the fluid port with your finger. What happens to the marshmallow?

Piston C Push the piston in with your finger off the port.

D Put your finger over the port and pull the piston back. Put in Marshmallow Watch the marshmallow.

8. What happened to the marshmallow? Answ e r: Press u re transfe rred from the piston, through the fl uid, to the mars hma llow.

Cylinder 9. Why, according to Pascal’s Law, did the marshmallow equally grow and shrink on all sides? Not e: Th e gas insid e th e mars hma llow expands and con tracts relating to th e outsid e p ress u re acting on it. Wh e n th e p ress u re insid e th e Finger c ylind e r is reduced, th e mars hma llow expands. Wh e n p ress u re insid e th e c ylind e r is inc reased, th e mars hma llow con tracts.

20 lbs 20 Note: Numbers used in 7 lbs this example are not real inside the cylinder. cylinder values. They are

for example purposes only. Formulas: Area of a circle = π • Radius2 P = Pressure F F = Force Calculate the P A A = Area Area of the Piston

Note: Measure an actual 14ml cylinder and find the area of its piston (do not measure the 0.3in Radius drawing on this paper or use the example area value).

Show your work below:

Area = π • Radius2

3.14 • 0.3in • 0.3in Area = 0.28in2

Calculate Pressure Pressure

20lbs F 2 P A .28in = 71.4lbs/in2 Answer: Finger over tip so The Air Pressure inside 2 no air escapes. the cylinder = 71.4psi (lbs/in )

Answer:

tip use colored water in hydraulic systems

A B Push One Piston Push and pull piston A . Examine what happens and answer all the questions below.

Complete the following sentences using some of these words (words can only be used once):

faster liquid slower

inversely transfers gas force

cut tubing length per fluid solid activity instructions

11. The pistons move inversely to each other.

12. Piston B moves slower than piston A (the piston you pushed and pulled) due to air compressing.

13. The pressure applied by piston A transfers through the fluid (air) to piston B , applying a force that causes piston B to move.

Push Both Pistons A B Push and pull both pistons. Examine what happens and answer all the questions below.

Complete the following sentences using some of these words (words can only be used once):

pressure force psi potential

compresses kinetic

cut tubing length per 14. An external is needed activity instructions force to move the pistons into the cylinders.

15. The pressure applied by the pistons compresses the air in the cylinders and line.

16. psi means the same thing as lbs/in2.

17. Compressed air has potential (stored) energy.

18. After pushing both pistons in, quickly let go of one piston. The piston you let go moves outward with kinetic energy.

© TeacherGeek I nc. P erm ission g rant ed f or e dit ing annda pd prriinnttiinng tg to scchhoooollss,so liibbrraarriieesl, as annd nd noonn--pprrooffiittss.. M at erir ia l s f o r this a ct iivvi t y located here. Page 11 Ad u l tlt ssupervisionn r e q u i r eed fd foor cr ch i l d r een un un d eer 1r 12 . FLUID POWER LAB sharing pressure & fluid How does fluid pressure transfer between cylinders? How can a force applied to one piston cause the other piston to move? Fill in the boxes below to find out. Force = Force

Piston C Applies Pressure 4 lbs 19. Complete the formula to find

the pressure applied by piston C :

F 40 lbs Pressure 2 = P A 2in C D

B 20. Pressure inside chamber G = 20 psi 2

Fluid Transfers the Pressure 2 21. Pressure is transmitted from chamber G G Area = .2in H through line to chamber .

I H Area = .2in

22. Pressure inside chamber H = 20 psi cut tubing length per activity instructions Piston D Turns Pressure into Force I 23. The fluid pressure applied to piston D = 20 psi Pressure Area

24. Complete the formula to F D find the force of piston : P A Force = psi • 2in2 We know pressure 20 and area , but need to find force Force of Piston = 40 lbs Master & Slave Cylinders . 25. The cylinders above can be referred to as a master cylinder and slave cylinder. Why do you think cylinder B is referred to as the slave cylinder?

The master cylinder controls the slave cylinder.

© TeacherGeek I nc. P erm ission g rant ed f or e dit ing annda pd prriinnttiinng tg to scchhoooollss,so liibbrraarriieesl, as annd nd noonn--pprrooffiittss.. M at erir ia l s f o r this a ct iivvi t y located here. Page 12 Ad u lltt ssupervisionn r e q u i r eed fd foor cr ch i l d r een un un d eer 1r 12 . FLUID POWER LAB friction Friction is a force that opposes the motion of an object, when the object is in contact with another object or surface. It turns some of the object’s kinetic energy into heat. A Grip the cylinder. B B Push and pull the piston 30 times, as fast as you can. 26. What happens to the cylinder as you move the piston? Why does this happen? It becomes warm from the friction between the piston A and cylinder wall.

How can you reduce friction When liquid flows in a in your hydraulic system? hydraulic circuit, friction Shorten the lines produces heat (wasted energy). Reduce bends in the line Properly size the line 27. Draw a line that would highly resist the flow of fluid between cylinders:

the line should be long and bend viscosity Viscosity: a measure of a fluid’s resistance to being deformed. Viscosity is a fluid’s resistance to flowing. water is thin ketchup is thick It can also be called its thickness. has low viscosity has high viscosity

28. Write the following words in the boxes below in order of least viscous to most viscous: Milk, Honey, Air, Peanut Butter

air milk honey peanut butter Least Viscous Most Viscous

© TeacherGeek I nc. P erm ission g rant ed f or e dit ing annda pd prriinnttiinng tg to scchhoooollss,so liibbrraarriieesl, as annd nd noonn--pprrooffiittss.. M at erir ia l s f o r this a ct iivvi t y located here. Page 13 Ad u lltt ssupervisionn r e q u i r eed fd foor cr ch i l d r een un un d eer 1r 12 . FLUID POWER LAB non-newtonian fluids Fluids without a constant viscosity are called Bonus Points "Non-Newtonian" fluids. You can experience Find a new use (good use) a Non-Newtonian fluid, here’s how: for a Non-Newtonian fluid. Present it to your class.

Mix two cups A fluid that changes points: cornstarch with viscosity depending on one cup water. + = the pressure applied to it. hydraulics Now we will use a liquid to transmit power between cylinders. For the remainder of the lab, you will need 14ml-14ml and 4.5ml-14ml hydraulic systems. Refer to the end of the lab for help.

Hydraulic Book Work Heavy Book Create the mechanism shown. B Pushing piston A should lift the book. Desk, Table, etc. 29. Show your teacher the completed mechanism. Explain how it changes Y force to pressure, transfers the pressure, 14ml Cylinder 14ml X and then changes it back to force. A Teacher Signature

14ml Cylinder

30. Push in piston A 5cm, 31. Pull back piston A 5cm, B piston B moves ~5cm cm piston moves ~5cm cm out of cylinder Y . into cylinder Y .

32. Pneumatic fluid is highly compressible. How compressible is hydraulic fluid? Hydraulic fluid is not very compressable (it appears not to compress).

33. When you push piston A , piston B moves immediately. How is that different than the pneumatic system you previously used? At first the pneumatic system compressed the air, rather than immediately moving the cylinder

Bubbles are Bad bad bubbles 34. Why is it bad to have air bubbles in a hydraulic system?

A Air bubbles will not compress, but hydraulic fluid will.

B x The air in the system will expand or contract, causing This is a tool the system to become delayed and transfer less pressure. for bleeding (removing the air from) brake C You can giggle and say that it "has gas". lines on cars. work The scientific definition of work: using a force to move an object a distance.

Work = Force • Distance

The force is the pull or The distance over the push on an object, which the output Force resulting in its movement. force is applied.

Forklifts use hydraulics to Work on Work perform work (moving loads).

35. If schools used the scientific definition for work, what would homework be?

Homework would be moving things.

36. The diagram on the right 3 shows cylinders that 16mm 24 7mm 8mm have lifted weights. 50mm 9 18

Place an under the cylinder that has done the most work. x

mechanical advantage A nutcracker allows you to apply a force larger Mechanical Advantage is the relationship than you could with your between the work going into a system, bare hand. and work coming out of a system.

smaller force larger force IMA vs. AMA applied over a applied over a Some energy will be lost by a machine larger distance: smaller distance: Force • Distance (mostly through friction). in in Forceout • Distance out

10lbs • 1in = 40lbs • .25in Ideal Mechanical Advantage (IMA) = 10in-lbs = 10in-lbs does not account for any energy lost.

Workin = Workout with IMA

Actual Mechanical Advantage (AMA) accounts for energy lost.

Workout < Workin with AMA Nutcracker Cracking a Nut Ideal Mechanical Advantage Work = Force • Distance Workout Work = Work This large cylinder in out moves a small distance with great force. Forcein• Distancein = Forceout• Distanceout

The distance over The distance over Input Force which the input Output Force which the output “Effort” force is applied “Load” force is applied Workin This small cylinder is repeatedly moved up and down (a large distance) with little force. 37. Calculate the output force:

Forcein• Distancein = Forceout• Distanceout

250lbs 25in 625 lbs 10in

Ideal Mechanical Advantage Distanceout = .02in Divide the Distancein by the Distanceout or the Forceout by the Forcein to find the mechanical advantage.

Force • Distance = Force • Distance Distancein in in out out = 6in

can be rearranged as 6in = 300 .02in Ideal Bottle Jack Distancein Forceout Mechanical = = The ideal mechanical advantage of the jack can be represented as: Advantage Distanceout Forcein "300" or "300:1" or "300 to 1"

Show your work. 38. Calculate the Forceout:

Forcein = 23lbs Ideal Mechanical

Advantage = 55 Forceout = 1265 lbs Distance for Force

Set up the 4.5ml-14ml hydraulic system, Heavy Book (the load) as shown, so it will lift a book. Experiment B with it and answer the questions below. Desk, Table, etc. 39. If piston A moves 1 inch, A piston B moves: .35in 14ml Cylinder 14ml 40. Complete the following formula to find B 4.5ml Cylinder the force at piston (Forceout).

Ideal Distancein Forceout 1in 17.14lbs Mechanical = = Advantage Distance Force 6lbs out in .35in

Calculate the Force out by cross multiplying. 41. Mechanical Advantage = 2.86

Set up the 4.5ml-14ml hydraulic system, A as shown, so it will lift a book. Experiment with it and answer the questions below. Desk, Table, etc.

42. If piston B moves 1 inch, B A piston moves: 1.42in 4.5ml Cylinder

43. Complete the following formula to find 14ml Cylinder the force at piston A (Force ). out Calculate the Force out by cross multiplying. Ideal Distancein Forceout 1in 2.11lbs Mechanical = = Advantage Distanceout Forcein 1.42in 6lbs

Calculate by dividing the Forceout by the Forcein

44. Mechanical Advantage = .35 or the Distancein by the Distanceout

Hint: This number should be less than one because this system loses force to gain distance. hydraulic cylinders = a lever Two connected hydraulic cylinders act like a lever, changing the force, distance, and direction of movement.

45. Label the Forcein and the Forceout 46. Label the Forcein and the Forceout on the cylinders below to show a on the cylinders below to show a mechanical advantage similar to mechanical advantage similar to the lever. the lever.

Force Forceout Forcein in Forceout Fulcrum Fulcrum (Pivot Point) (Pivot Point)

Forceout Forcein

Forcein Forceout

Force = Force

Input Force 8 lbs = 8lbs

2" Input 2lbs 2" Distance 2lbs B Piston Area B = 1in = 4in2 2lbs 2lbs

Fluid Pressure C Pressure = Pressure

= 2psi lbs/in 2 C 4"

2 2lbs Piston Area 2lbs = 16in 2 2lbs 2lbs 4" 2lbs 2lbs 2lbs 2lbs D 2lbs Hydraulic Fluid 2lbs 2lbs Piston D 2lbs 2lbs 2lbs Output 2lbs 2lbs Distance = .25in Force = Output 32 lbs Force = 32lbs

8lbs of force is applied to piston B .

The 8lbs of force is divided over the area of piston B and transferred to the fluid ( C ): Force 8lbs Fluid Pressure = 2lbs/in2 2 Piston’s Area 4in Pressure is transferred through fluid C (Pascal’s Law) to piston D .

Fluid C presses against every square inch of piston D , creating 32lbs of force:

Fluid Pressure Area of Piston D Output Force

Note: The /in2 and in2 2lbs/in2 • 16in 2 = 32lbs cancel each other out. Piston D applies a downward force of 32lbs.

A. Find the Forceout, Distanceout and mechanical advantage of the hydraulic system below. Show all work.

2 Pressure developed from force applied over piston area: 2.54in Force = 6lbs F Area = 2.54in2 xP A Area of a circle = π • Radius2 3.14 • .92= 2.54in2

Piston Diameter = .6in

Forcein = 6lbs

Distancein = .3in

Piston force developed from fluid pressure over piston area:

2.36lbs/in2 •.22in2 = .52lbs

Forceout = .52lbs

Piston Diameter = .35in

Distanceout = 2.31in x F P A .2in .52lbs = = mechanical advantage Distanceout 6lbs

Mechanical Advantage =

Presentation Is it well drawn and easy to understand? /3

Function Could it really work? Does it use fluid power? /3

Creativity Does it solve the task in a new and different way? /4

total points: /10 congratulations!! You’ve finished the Fluid Power Lab. It’s time to create a fluid powered contraption.

Pneumatics Have one cylinder all the way open. One cylinder all the way closed.

Connect cylinders with tubing. (use length shown on page 2).

Hydraulics

Fill both cylinders with water: Attach tubing (as noted for activity) to filled cylinder. A Push cylinder piston in B Place cylinder tip underwater Water

Water

C Pull piston back to completely Water fill the cylinder with water connection close-up

Water Fill the tubing completely with water by pushing the piston completely in. Water

Attach the water-filled tubing Insert a cylinder screw to the remaining water-filled as shown to prevent the cylinder from Step 1. tubing from pulling off.

Water

cylinder screw