[Stoves] Bisschop - part 3

[Jeff Davis]

Dear List,

Stovers, this would make a cottage industry for people in the 3rd world.


rom “Internal Fire”
by Lyle Cummins



Customers were attracted to the Bisschop engine for two other reasons: it was 
compact and required no cooling water. Floor space was reduced by making the 
cylinder verticle, and the height was kept low by offsetting the flywheel and 
placing it below the top of the crosshead guide. The linkage was arranged so 
that, at the time of maximum cylinder pressure, the piston rod and the rod 
tying the crank throw to the piston rod crosshead were almost parallel to 
each other. Piston side thrust thus was nil, and the crosshead guide 
structure consequently could be kept light. The engine was air cooled (a 
first) with large fins cast on the cylinder to carry away heat from the 
combustion chamber. The piston ran hotter than in other engines of that 
period and had to be fitted quite loosly in the cylinder. There were no 
piston rings, but the pressures (twenty-five psi and under) were low enough 
that blowby was tolerable. Because of the hotter piston, lubrication oil was 
deliberatly kept out of the cylinder to prevent carbon deposits from building 
up in the combustion chamber. (Coal gas of the nineteenth century had an 
inherent lubricating characteristic and left a tar-like residue. In all 
probability many early designs were saved from failure for this reason.) 
Lubricating oil was needed only for the bearings. One of the Bisschop engines 
reportedly ran forty-seven days without stopping.


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To be continued,

Jeff

-- 
Jeff Davis
Somewhere 20 miles south of Lake Erie, USA
http://www.velocity.net/~jeff0124