Steam Engine Specifications

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Summary

• Deliverable: a one cylinder prototype module with scalability, to constitute a single stage of a stageable system (compound or 3 stage) which uses the same module that is scaled to make other stages
• System consists of cyliner, crank arm, mechanical valve, automatically adjusted cutoff ratio, and constitutes a Steam Engine Construction Set
  • Cutoff ratio controlled by closed loop electronic feedback with some type of linear actuator
• Applications to stationary, mobile, and solar power

Cost-Related Features

• Lowest materials cost for a given performance
• Simplest to fabricate, therefore lowest fabrication cost
• Advanced techniques of fabrication utilized only when necessary to achieve cost
• Fabrication tooling preferably simple, but secondary to fabrication cost
• Uses commonly available parts
• Replicable
• Materials cost of $50/hp

Materials Calculations

• 20 pounds of weigh per horsepower

Steel weights .2833 pounds per cubic inch

Flexibility and Performance

• Scalable in power output from 1 - 100 hp by scaling or adding modules
• Power density of 1 hp/10 lb
• Pressure up to 500 psi
• Scalable cylinder dimensions, uncoupled staging, and tandem operation allows scaling of power and eficiency from 1-100 hp and up to 25% efficiency
  • Multiple cylinder, in-line configuration is possible by bolting several cylinders together

See the following for steam engine calculations:

• Steam Engine Construction Set Calculations
• Steam Engine Efficiency Calculations
• Steam Engine Efficiency

Lifecycle

• Long lifetime under continuous use (50 years)

Ecology

• Compatible with stationary, solar, and mobile power applications
  • LifeTrac power source
  • Solar Power Generator heat engine
  • CHP with space heating

Sources

• Steam Engine Specifications/Piston Ring Sources
• Steam Engine Specifications/Cylinder Liner Sources
• Steam Engine Specifications/Bearing Sources
• Steam Engine Specifications/Valve Spring Sources

Parts List

The following list of parts is based on the initial set of technical drawings linked from Steam Engine Build Instructions.

Steam Engine Parts

• Piston Assembly
  • Piston (1)
    • Piston Head (1)
    • Piston Stem (1)
    • Piston Stem Pin (1)
    • Piston Stem Pin Washer (1)
    • Piston Stem Pin Cotter (1)
  • Piston Rings (2)
  • Bump Valve Pins (2)
  • Connector Rod (1)
    • Coupler (1)
    • Rod (1)
    • Bearing Case Assembly (1)
      • Bearing Case Top (1)
      • Bearing Case Bottom (1)
      • Quarter Inch Bolts, 3/4" long (2)
      • Quarter Inch Nuts (2)
      • Quarter Inch Lock Whaters (2)
• Cylinder Assembly
  • Cylinder Liner (1)
  • Cylinder Case (1)
    • Cylinder Pipe (1)
    • Cylinder Flanges (2) - Flanges are missing four bolt holes
  • Valve Seat Plate (1)
  • [Valve Seat Seal ???] - this is a thin, soft metal seal.
  • Cylinder End Mount (1)
    • Plate (1)
    • Flange (1)
    • Half Inch Base Bolts, 1" long (3)
  • Exhaust Plenum
    • Exhaust Plenum Elements (4)
    • Quarter Inch Plenum Bolts, 1.5" long (4)
    • Quarter Inch Plenum Lock Washers (4)
    • Quarter Inch Plenum Nuts (4)
  • Half Inch Cylinder End Bolts (8) - Bolts can be replaced by a threaded rod.
  • Half Inch Cylinder End Lock Washers (8)
  • Half Inch Cylinder End Nuts (8)
• Valve Assembly
  • Valves (2)
  • Valve Springs (2)
  • Vavle Spring Base (2)
  • Valve Cover (1) - Cover could be extended to eliminate the mounting bracket
    • Valve Holder (1)
    • Valve Cover Plate (1)
    • Valve Cover Flanges (4)
  • [Valve Cover Seal ???] - this is a thin, soft metal seal.
  • Cylinder Mounting Bracket - has two base plate holes, but cylinder end mount has 3.
    • Upright Plate (1)
    • Flange (1)
    • Half Inch Base Bolts (2?)
  • Half Inch Valve End Bolts (8) - Bolts can be replaced by a threaded rod.
  • Half Inch Valve End Lock Washers (8)
  • Half Inch Valve End Nuts (8)
• Other
  • Base Plate (1)
  • Oil Dribbler - TBD (1)

Crankshaft Parts

• Shaft
  • Flywheel Shaft (1)
  • Drive Shaft (1)
• Crank Assembly (1)
  • Crank Pin (1)
  • Crank Counterweight (2)
  • Crank Arm (2)
  • Nylon Bushings, 0.5" long (2)
• Pillow Block Assembly (2)
  • Pillow Block Bearings (2)
  • Supoprt Element (1 - 2 total)
  • Support Base (1 - 2 total)
  • Support Rods (2 - 4 total)
  • Half Inch Pillow Block Bolts, 2" long (2 - 4 total)
  • Half Inch Pillow Block Lock Washers (2 - 4 total)
  • Half Inch Pillow Block Nuts (2 - 4 total)
  • Half Inch Base Bolts (2 - 4 total)
• Flywheel Assembly (1)
  • Flywheel (1)
  • Collar (1)
  • Quarter Inch Set Screws, 0.5" long (2)

Techniques

• Stock parts wherever feasible
• Lathing for valves and other parts
• Milling of exhaust plenum and other parts
• Hole drilling
• Cylinder boring may be necessary, depending on stock availability
• Welding of parts in several places

Specification Decisions

There are a few key dimensions that need to be specified before the full dimensions of the engine and it's parts are known. These include:

• Valve Gap - the amount of space open in the valves at top dead center.
  • Initially, we shall use 1/8" (0.125"). This can be adjusted by changing the valve pin length.
• I.D. of a half inch bolt - needed to determine valve spring holes and valve stem diameter.
  • O.D. is 0.515", I.D. is 0.482". However, this might not be the size of the hole we need. See valve spring size.
• Cylinder clearance - space remaining in the bore at top dead center.
  • "Steam Engines" recommends 3-8% of the piston displacement, which is 4". If we assume 6%, this is a clearance of 0.24, which we can round off to 0.25 (1/4 inch).
• Exhaust port locations - near bottom dead center
  • We will use 3.6" from T.D.C as the left edge of the exhaust holes, which shall be 0.25" in diameter..