Stirling engine , contrary to appearances, is something completely different than the steam engine. Taking into account the numerous publications on the Internet on this subject will not be there for him nothing more than a description of the implementation and observations based on experience. relative simplicity of the engine is coupled with the fundamental difficulty of execution - pinpoint accuracy, which is a prerequisite for its efficiency and response of the minimum temperature difference between top and bottom plates. For success in this regard, we consider the efficiency of the engine allows you to work with the hand warm. Quite an interesting variant of the engine is driven by solar radiation energy (the upper transparent plate and the upper surface of the piston displacement painted black).
engine described here is of course no intention of asset utility and its use to drive such a generator can be immediately dismissed as not quite real. General:
- Materials - part of the drive (bearings), aluminum (brass), polystyrene in the piston displacement, 0.5 mm steel wire, the axis of motor electrical bearing bushes, plastic section of sewer pipe cross-section of 100 mm, brass pipe, screws, nuts M3 screws M2, very thin rubber band.
- Tools - Precision drilling machine (drilled holes 1mm), a small lathe, grinder, taps 2 and 3 mm,
Notes on completion:
- The cylinder piston displacement (should I start from the cylinder, because its dimensions will determine the other dimensions of the engine) is a cylinder with dimensions of 100x22x3 mm - any material, as a good insulator. Very effective solution is a cylinder of glass or plexiglass, but given the difficulties with obtaining and processing of glass tubing can be used with equal success section of a plastic sewer pipe with a diameter of about 100 mm. Cylinder carrying paying close attention to the centric and the exact height of 22 mm around the perimeter. In the first approach used a ring cut from a sewage pipe caps - it turned out that it is slightly tapered (0.5 mm at a height of 22mm) - it was a lot of work from rolling to a perfect equality of the cylinder.
- Piston Displacement - without a doubt the best of the available material is polystyrene. The dimensions of the piston: 10 mm height, diameter 2 - 3 mm inner diameter smaller than the cylinder. Contrary to appearances, it is not difficult to be done. Phase I - pre-treatment, a very sharp knife, disc on fast speed lathes (drills). Phase II - after fitting (sealing) the disc on the axis of 2 mm (eg electric motor), we are in the piston to the desired size using increasingly finer sandpaper. We pay special attention to the lack of "beatings" during the rotation and perpendicular shafts (when the piston is approaching the work your entire surface of the upper and lower plate at a distance of 0.5 to 1mm. Any rubbing of the piston cylinder wall and touching the top (bottom) of the lid will cause the engine will not work. Note, for bonding polystyrene (mounting rod) can not be used polystyrene resin-soluble! In the present engine performed perfectly Wikol glue. Second note: in order to ensure the eccentricity in the piston rod attachment displacement, when pushed on the piston Styrofoam glue to assemble the entire top plate previously prepared with the sleeves and leave for a few hours to bind the adhesive. Cast a Teflon rod gear, which - after nagwintowaniu with tap M2 - pressed rod.
- cylinder covers - made from sheet metal (good conductive heat) np.aluminiowej. The top cover may be thicker (2 - 3 - 5 mm) because they assemble on the other engine components. The cover brings the groove width and depth of the walls of the cylinder about 0.5 mm, which ensures that the cylinder piston centric. A more simple way to attach the upper plate disc of aluminum sheet 0.5 - 1 mm, the same diameter as the inner cylinder. The lower lid can be made of sheet thickness of 1 - 2 mm. At the periphery of the cover (outside diameter of the cylinder + screw 3mm) drill 6 (thicker sheet) to 8 (thinner plates) 3mm holes for the fastening bolts. Holes drilled in both of these compartments and highlight their relative position. Before the final twisting of the cylinder, the upper and lower edge of the silicone grease seal.
- Keeping the piston displacement - a crucial condition on the efficiency Output: a maximum leakage with minimal resistance, movement of the piston rod. This condition will meet as a thin rod (1.5 - 2 mm) with polished steel moving in the bushes of bronze. Rod with a length of about 40 mm can be found in the old electro-mechanical equipment (printers, disks, calculating machines, etc). in the described model is utilized OŚKA electric motor from the oven along with the bushings.
- working piston - in a simplified version of the membrane is very thin bands (permitted from the age of 18) on the ring with a diameter of about 20 mm. stroke diaphragm 8 - 10 mm. For the efficiency of the engine is so very important rubber stress that at no position (upper, lower) will not be followed if you have a spoof gumy.W glass syringe may be tempted to carry a cylinder of graphite (najlepiej!) piston. The hardest version of a metal cylinder and piston.
- flywheel - about 12 cm in diameter, the material - complete freedom. In the present model of the role of the flywheel to successfully meet the CD plate. Flywheel with the eccentrics are mounted on bearings obtained the floppy disk drive (or other device). Bearing flywheel largely determines the engine. Reinvent the flywheel (small pieces of plasticine) after the whole engine.
- eccentrics and connecting rods - Connecting rods made of brass and brings them 1 mm holes drilled in the area that will allow the desired stroke of the pistons. In a split paste tip openings of 1 mm drill. Rods are made from steel wire of 0.5 mm at their tips forming a mesh diameter is made for 1mm.Dobrze minimum length adjustment rod, for example by bending in the shape of the letter "Z". You may also be 'compress' and pan made from graphite (as in the pictures below). Presented in some embodiments, the connecting rods on ball bearings appear to be a triumph of form over content - to obtain a measurable effect in the amateur is very difficult. Note: The rods must be positioned 90 degrees relative to each other!
eccentric displacement piston is mounted on the shaft of the building (to be pressed in). Eccentricity of the working piston has a screw terminal, which allows you to set the connecting rods relative to each other by an angle of 90 degrees.
Tips dimensions:
- cylinder height - about 1 / 5 to 1 / 10 in diameter (for the ratio of 1 / 10 the engine will at a lower temperature difference).
- The amount of piston displacement - about 60% of the cylinder.
- Bore displacement - about 97% of the inner diameter of the cylinder.
- Bore work - about 1 / 8 to 1 / 10 the diameter of the cylinder. (Membranes - 1 / 4 cylinder diameter).
- Stroke work - about 1.3 of the cylinder.
And once again of the correct structure:
- maximum tightness shells piston displacement.
- maximum piston seal working (Small).
- minimum resistance to motion of pistons, the maximum flexibility to the membrane.
- minimum gap piston displacement in the upper and lower turning point (0.5 - 0.3 mm).
- Excellent bearing and balance the flywheel.
- good thermal insulation between the lower and upper plate.
Effects:
Engine starts on a cup of boiled water, which indicates that the differential runs at about 70 - 80 degrees C. The plate on top of pieces of ice causes a radical increase in turnover.
For ambitious:
Stirling engines share (regardless of the type of structure) into two broad types:
- low temperature (described above),
- high temperature.
Use low temperature engine as power source is very problematic. The power of such an engine just enough to overcome the resistance of the structure, possibly - using a flywheel generator as part of a "micro-american" to power the LEDs. Low-temperature structures to ensure the practical use (a few watts of power) would have to have diameters of the order of meters! Despite all the experimentation in this area provides a lot of satisfaction - is an excellent test of our "watch-making" skills and allows you to break records for a minimum temperature difference at which sinik works. Engine przacujący on hand (a few degrees of temperature difference) is already a championship, but there is nothing to prevent the attempt to construct the engine at the difference a few degrees!
High Engines This structure theory efficiency in excess of internal combustion engines, especially steam. They are used to drive electric generators, ships and even submarines. Engines of this type performed in amateur may have a use purely for show - Teaching (engines "spin" heated candle) or structures more serious - to drive vehicle models.
movie of the above. Motor: http://www.youtube.com/watch?v=zGDa0qtwg2I
and http://www.youtube.com/watch?v=IOzF3fDJTP8
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