Employing suitable valving, the motor
can be operated at two levels of speed and torque output at the
same operating pressure and flow rate of fluid. Simultaneous pressurization
of the pistons in both rotors produces the "wedge effect",
driving both rotors with equal power and higher torque. The interactive
function of the pistons assures optimum transmission of the driving
torque between the rotors by distributing the load to all pistons.
This exceptionally high torque efficiency allows direct drive
of the propeller without gears, and the using only medium rather
than high pressure pumps.
motors are bi-directional, and the direction of the rotation can
be selected externally by valves, or internally by interchangeable
valve plates. The motors have automatic hydraulic pressure and propeller
thrust compensation. The replacement of the mechanical transmission
by hydraulic components provides a stepless speed control from stand
still to full speed, as well as instant reversal, reportedly assuring
the availability of full power at any moment.
no mechanical connections between the engine and the propeller drive
units, the marine designer has complete freedom in the positioning
of single or multiple propeller drives and the engine units themselves.
number of bow thruster units are in service. The potential applications
for these motors go far beyond the marine field. Their
simplicity and light weight make them prime candidates for the aircraft
industry,etc.,etc. Venture capital is being sought.
am particularly interested in the adaptation of the new generation,
ultra-high strength, power transmission belts to the marine drive
situation. Their aramid fiber tensile cords are imparting extraordinary
strength and load carrying power. They are tough....you can hardly
cut it. They have a higher modulus than steel and virtually zero
elongation. The fatigue life is exceptional and its high impact
strength withstands shock and surge loading. The fibers are also
thermally stable thus remaining operational under extreme temperatures,
and they are chemically inert to resist oils, chemicals, pollutants,
corrosion, etc. Their toothed design results in a positive slip-proof
engagement. Unlike flat and V-belts, they do not rely on friction
for their pulling power, and thus tension and loads to the bearings
see these belts being used in an ever increasing number of applications,
and particularly in many heavy industrial equipment drives.
Load capabilities range from fractional to hundreds of horsepower.
Just two visual examples...replacing Harley Davidson motorcycle
chains and driving superchargers on hi-powered dragsters. So why
no marine applications?
there are quite a number of individual small projects that have
been done, but there is no central source of data or records related
to these examples, and no attempt to do a general concept that might
have a greater adaptability throughout the marine field. Within
this site we hope to gather the past records of both failed and
successful marine belt-drive projects and continue to evaluate the
potentials. I presently have some info on several small projects,
and I have done a patent search on similar drives at the US Patent
office here in Washington, DC.
than direct straight-shaft drive of propellers, most marine drives
today involve some sort of 90 degree arrangement, ie.sail drives,
stern outdrives, outboards, etc. The 90 degree gear set (and there
are usually two sets) is the potential weak link in the system.
All the power is being transferred over a very physical small contact
area between two bevel gears. This contact patch can be nothing
more than a thin line on the opposing two teeth! Special hardened
gears and maintaining close-fit tolerances permit the horsepowers
of today. But when it comes to diesel engines, the situation gets
worst. The diesel is by its nature a much more torque'y beast. Gears
to handle an even modest horsepower diesel are extra hard pressed.
Teeth can break or get worn so quickly as to loose all tolerance.
belt-drive configuration could eliminate both sets of 90 degree
gears. And if desired the drive system might be rotatable about
the shaft opposite the prop shaft end (the prop could be rotated
out of the water when not in use). I've included just a couple of
quick, undetailed sketches at this time......