Bulldozer Specification

• Use same frame as LifeTrac with modifications
  • LifeTrac is 4"x4"x1/4" tubing, the bulldozer should identical frame with 3/8" or 1/2" wall thickness instead of 1/4" walls - for design redundancy compared to the LifeTrac platform
• Vehicle weight should be approximately 20,000 lb - or about 7,000 lb of metal and with modular concrete blocks providing the remainder of the necessary weight
  • Metal frame should be a space frame to save materials while providing necessary structural stability
• 8 foot wide 6-way Blade - should be 3" wider than body for clearance
• Use 4 Power Cubes for 128 hp of tractor power
  • Use 2 Power Cubes per side to simplify hydraulic plumbing requirements
• 3000 psi hydraulic system pressure
• Cushion Valve on each wheel
• 15,000 inch pound hydraulic motor on each wheel
  • Each wheel has 6-fold gear reduction via Jackshaft
  • Jack shaft uses heavy chain and sprockets
  • Number of jackshafts is 3 for the gearbox; oil-enclosed gear box
• 30 gpm quick couplers on motors, valves, and cylinders
• Use metal wheels as in Traction Engines
• 42" diameter wheels, can be as wide as required to achieve desired traction
  • Dually configuration is favored for modularity, so each wheel may be handled more easily.
  • Tighten-on bolt clams key in keyway to lock wheel to shaft; this allows easy take-off of the wheel without having to fight to get a key out
• Use 4-flange pillow block bearings with quick-disconnect wheels - see Quick Connect Wheels strategy for LifeTrac
• Use 3" shaft
• 3" bearings - https://www.surpluscenter.com/item.asp?item=1-215-48-4-C&catname=powerTrans
• 4 wheel drive
• Must use bolt-through wheel attachment to shaft as in LifeTrac, for maximum wheel mounting simplicity
• Complete materials cost estimate of under $16k in materials, not counting
• 20,000 pound gross vehicle weight, weighed down with modular concrete weights
• 24,000 lb of pushing force

Challenges

• Low cost ($20/linear foot for jackshaft [x3], sprocket for #100 chain - , chain - $6/foot or 9 feet total
• Cost/performance differences between tracks and steel wheels including design for fabrication aspects - see Comparison of Steel Tracks vs. Steel Wheels

Deployment Suggestions

• 3 separate design challenge for:
  • Main structure - frame, wheels, power cube mounts, hydraulic controls
  • 6-way Blade and fabrication procedure for it, inlcuding fabrication procedure for 8' shop press using 5"x20"x2.5" Cylinders
  • 6-fold Gear reduction mechanism via jackshaft and roller chain
• All points are negotiable provided compliance with OSE Specifications

Calculations

• Wheel coupler force requirements of double chain couplers - see Double Chain Coupler for specifications.