Introduction: Air Tire Pump
This Instructable is mainly made of scrap materials and cost me about $20 Australian dollars from my local bloke hardware for those 'few extra bits'.
The principle of this design is a tyre is used as the bladder and this is moved up and down via a crank (hand driven in my case with the option to be driven by motor). Air is directed through the tire using simple one way valves, as the tire is raised and expanded mechanicly air is drawn thru the one way valves (intake side),into the tyre.
Then as the crank forces the tyre to a squashed postion the air is forced through the bottom one-way valve and to your piping.
Uses for this project could include: air for a foundry, aerating water, filling balloons, pumping water ect.
With this re- use of a tyre, you could scale it both ways and get great results, e.g. a small model aeroplane tyre hooked up to a 12v motor would be a great fish tank oxygenator or a larger truck tyre version could keep an aquaculture company aerated.
Those willing to change the valves around could also pump water.
Also if you are going to put this into long term use I recommend using proper bushing and bearing techniques, as I have not designed this one to be used for long.
Step 1: Things You Need
THINGS YOU NEED
Tyre and inner tube, Wheel barrow wheel in my model.
bolts out of your own collection or local shop,
suitable hose connector, to suit your piping
3mm (1/8th) steel plate,
40mm x 3mm steel flat bar approx 1 meter ,
Steel tube 75mm x 38mm approx 2.5 meters ,
rivets and washers to suit,
70mm I.D pipe (50mm long)
PARTS YOU WILL MAKE
Base, Five anchor pionts, At least three valves, Rocker arm, Crank (optional motor drive), Air chamber, Two tyre anchor plates.
Welder / or tech screws if you want to do it differently,
20mm reduced shank drill
Step 2: Cautions
Wear appropriate safety equipment.
File sharp edges after cutting.
Welded steel is hot.
Shield all rubber from weld splatter.
Step 3: Anchor Points
Cut five pieces of 40mm x 3mm flat bar at 70mm long and drill a hole suitable for your bolts appox 10mm from one end. (Rounding of the corners on this hole end is a nice finish).
Step 4: The Base
For the BASE I used 38mm x 75mm galvinised tube, this piece is the center and also allows air to flow to the hose connector, (middle tube), the tyre will be placed in the middle distance from both ends.
The second is welded as a T shape to the base (air tight) at 90 degrees to the middle tube end and is for stabalizing the pump.
The third piece of tube is welded (air tight) at the base end of the T-shape and will support the anchor points for the ROCKER ARM (see step number 7 ).
For connecting and anchoring the tire. Drill a 20mm hole in the centre of the middle tube then weld a 50mm long piece of 70mm I.D pipe vertically over the hole (air tight).
For a place for the hose connector to go. Drill a hole in Middle Tube at a good distance from where the tyre will be and clear of the vertical tube. weld connector over hole (Air tight).
Tyre Anchor Plates:
Cut two pieces of 3mm steel plate 50mm (2'') larger diameter than the inner diameter of your tyre, (the part that joins the rim). I measured approx 230mm diameter on my wheelbarrow wheel so I cut 280mm diameter. (Use a thicker guage of plate if you are using larger tyres)
Take ONE of the 3mm plates and drill a central 20mm hole and file burrs. Weld this plate over the 70mm I.D pipe that you have welded to the base. Weld air tight and try to keep things fairly central. This now is called the BASE TIRE ANCHOR PLATE.
For the second 280mm diameter plate. Weld one ANCHOR POINT from STEP three to the centreline. This now becomes the TOP TYRE ANCHOR PLATE.
Step 5: Valves
Valves were the hardest to design with many options available including buying some expensive brass (not weldable) types.
You may also know these valves as: Reed valves, Check valves, Clack valves, Non-return valves.
These one way valves use a piece of movable material as a valve. Rubber in my design, (leather or flat spring steel would work). This valve is pressed against the seal surface in one direction if the fluid tries to flow backwards through the valve.
If the presure on the inlet side of the valve is higher than the outlet side the valve will open because there is no physical barrier on the outlet side to hold it shut.
If the pressure is reversed and is higher on the outlet side the valve material is forced against the sealing surface (smaller hole of the KEEPER PLATE) making the fluid unable to pass through.
1.The outlet valve in the base should be in the middle of where the tyre is going to be. Mark this point and drill a 20mm (3/4 inch) hole filing rough edges.
2. Cut 3 pieces of inner tube rubber approx 70mm sq.
Two for inlet valves
I found that two on the inlet side made the pumping easier and it did not seam to need two on the outlet side.
Mark these in the centre with a 20mm round object.
A helpful hint for fitting the valve pieces together is marking the centre of this rubber piece with a white dot (for step 4).
Cut a horseshoe shape around the 20mm circle you have marked see photo three (the outer diameter slightly bigger than 20mm and the inner diameter slightly smaller, test the inner size of the horseshoe cutout for free movement inside the 20mm hole of the base TYRE ANCHOR PLATE)
Hint, having the natural curve of the rubber (inner tube) curving back to the seal surface (not away from) seemed to create a better seal, flat rubber would not matter which way up it was.
KEEPER PLATE /Seal surface sized hole
3. Cut 3 pieces of 3mm steel plate 70mm x 70mm (two for inlet valves) drill a 12mm hole in the centre and de-burr. This is a smaller hole so there is a seal surface for the valve flap to seal on.
4. Place the rubber so the flap is centrall and has free movement over the 20mm hole,
then carefully without moving the rubber place the keeper plate over the rubber using white dot to align centre,
Hold down keeper firmly (I used multigrips) and drill four rivets approx 12mm from edges of KEEPER PLATE.
5. Test valve by blowing through the 12mm hole, then try to suck air in, you should not be able to, this means your valve is working.
See picture 2, wait for cooling before attempting :)
( same as outlet valves except)
1. Inlet valves are on the TOP TYRE ANCHOR PLATE
2.Make shure the valves are well away from the sealing edge of anchor plate (see photo
3. Repeat steps 4 and 5 of OUTLET VALVE
Step 6: THE Tyre
I had to check for leaks in the tyre as I got it off a scrap pile and had no idea of the condition it was in.
I discovered there was plenty of holes.
Silicon, what would we do without silicon.
I spread silicon all over the inside tyre aprox 1mm thick using a piece of conveniently shaped cardboard.
Let silicon skin over (dry to touch but soft underneath).
Force one seal lip of tyre over BASE TYRE ANCHOR PLATE. Turn base up side down, silicon and rivet to tyres seal lip so that it is an air tight joint.
Use a washer on rivets to stop them pulling through the rubber tyre wall.
Repeat above for the TOP TYRE ANCHOR PLATE making sure that you line up the welded ANCHOR POINT so it runs in line with MIDDLE TUBE of your base and later the ROCKER ARM (next step)
For the impatient.
You may gently raise and lower your new tyre bellows to see how it is all going.
Don't Disturb the silicone too much though.
Step 7: Rocker Arm
To make the Rocker Arm cut a piece of 75mm x 38mm tube the same length as the base total length.
Drill a hole through the 75mm length and 20mm from the end the same diameter as you drilled your ANCHOR POINTS
(this hole is the pivot point for the ROCKER ARM)
Get a long bolt and attach an ANCHOR POINT either side of the ROCKER ARM, place the ANCHOR POINTS over the VERTICAL BASE aprox 20mm down.
Clamp and Weld the points when ROCKER ARM is aligned with center line of tyre.
Allign another ANCHOR POINT to the ROCKER ARM above the tyre centre and weld. This one is for the CONNECTING ROD between the ROCKER ARM and the TOP TIRE ANCHOR POINT.
Weld final ANCHOR POINT to the ROCKER ARM with the same spacing as between the ROCKER ARM PIVOT POINT and the middle ANCHOR POINT.
Make two CONNECTING RODS (2) 40mm x 3mm flat bar.
To work out distance of hole centres Squash the TOP TYRE ANCHOR PLATE down about 5mm off of the BASE TYRE ANCHOR PLATE. Then with a level on top of ROCKER ARM measure the distance between middle ANCHOR POINT hole and tyre ANCHOR POINT hole ( you may need a helper).
Add 40mm to your measurement as the overall length of CONNECTING RODS.
Drill holes 20mm in from ends to suit your bolt sizes.
Step 8: CRANK
Crank length you must work out for your design.
The tyre must be able to stretch and contract without contacting the two TYRE ANCHOR PLATES or be over stretched, see ROCKER ARM step 7.
With the top ROCKER ARM bolted at the pivot point, and the middle CONNECTION ROD attached.
Push down on the rocker arm until the TOP ANCHOR PLATE is on the BOTTOM ANCHOR PLATE (squash the tire flat), then lift it 5mm (aprox), Measure between the floor and the top of the ROCKER ARM.
Lift the ROCKER ARM to stretch the tyre up to where any more stretch on a regular running of the pump might break the tyre seals, MEASURE the floor to ROCKER ARM distance again.
Subtract the first distance from the second measurement and divide by 2 equals the distance between the crank pin (a bolt welded onto the disc) and the crank shaft.
I used more 78mm x38mm tube for the support of my crank assembly.
Crank pin center height and crank handle arm length needs to be at a distance above the base so that you dont crack your knuckles on the floor when using the Hand driven option.
You do not have to use a round disc as I have, More flat bar would do.
Step 9: Final Blah
Connect up a hose, fill a tub or bucket with water place hose in water and crank that handle.
I Know you have skipped to this step allready.
This project was completed in a day as you may have seen in the photo's.
Hope you enjoy this simple pump that may well be an answer to many problems.
Add grease and spacer washers around moving joints.