Hulsebos-Hesselman axial oil engines were five cylinder, four stroke,
wobble plate engines that originated in and were used throughout the Netherlands during the late 1930s.
Numerous patents can be found concerning this engine,
all of which appear to attribute the engine's "wabbler" operating principles to the inventor Wichert Hulsebos.
Combustion system
This engine used the
Hesselman engine
The Hesselman engine is a hybrid between a petrol engine and a diesel engine. It was designed and introduced in 1925 by Sweden, Swedish engineer Jonas Hesselman.
In a Hesselman engine, fuel is not injected during the suction stroke along with th ...
low compression combustion system where oils of varying grades were sprayed into the cylinder during compression but ignition was initiated and assisted by a
spark plug
A spark plug (sometimes, in British English, a sparking plug, and, colloquially, a plug) is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air ...
.
Overhead inlet and exhaust valves, water cooling and a
magneto
A magneto is an electrical generator that uses permanent magnets to produce periodic pulses of alternating current. Unlike a dynamo, a magneto does not contain a commutator to produce direct current. It is categorized as a form of alternator, ...
for ignition were standard features.
Dimensions
The capacity of 4 litres was achieved with a bore of 95 mm and a stroke of 114 mm and it made use of a
compression ratio
The compression ratio is the ratio between the maximum and minimum volume during the compression stage of the power cycle in a piston or Wankel engine.
A fundamental specification for such engines, it can be measured in two different ways. Th ...
of 6 to 1. Power output was said to be 70 bhp at 2400 rpm.
Wobble plate arrangement
The wobble plate arrangement cleverly employed a bevel gear set to prevent its rotation around the crankshaft. One bevel gear was fitted to the rear of the wobble plate itself and meshed with another which was fixed to the main body of the engine.
Production
They were manufactured by Hulsemo N.V., Casimirlaan 5, Arnhem, The Netherlands, and were exhibited in the Berlin and Amsterdam Shows during 1938.
References
{{Reflist
Diesel engines
Engine technology