US 11,952,937 B2
Two-stroke engine
Michael Grether, Waiblingen (DE); Robert Koehli, Winnenden (DE); Richard Wirt, Waiblingen (DE); and Bernd Engel, Stuttgart (DE)
Assigned to Andreas Stihl AG & Co. KG, Waiblingen (DE)
Filed by Andreas Stihl AG & Co. KG, Waiblingen (DE)
Filed on Jun. 13, 2023, as Appl. No. 18/334,193.
Claims priority of application No. 22178631 (EP), filed on Jun. 13, 2022.
Prior Publication US 2023/0399973 A1, Dec. 14, 2023
Int. Cl. F02B 25/00 (2006.01); F02B 33/02 (2006.01); F02B 75/02 (2006.01)
CPC F02B 33/02 (2013.01) [F02B 75/02 (2013.01); F02B 2075/025 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A two-stroke engine comprising:
a cylinder having a cylinder bore;
a combustion chamber formed in said cylinder bore;
a crankcase defining a crankcase interior;
a crankshaft rotatably mounted in said crankcase;
a reciprocating piston configured to drive said crankshaft;
said combustion chamber being bounded by said reciprocating piston;
at least one transfer channel;
said crankcase interior being fluidically connected to said combustion chamber across said at least one transfer channel in at least one position of said reciprocating piston;
said at least one transfer channel emerging with a discharge opening in said crankcase interior and emerging with at least one transfer window on said cylinder bore;
an intake channel;
a fuel supply unit for supplying of fuel to said intake channel or said crankcase interior;
an outlet opening from said combustion chamber;
wherein all of said at least one transfer channels have an average length as measured from said discharge opening to said transfer window;
wherein said average length of said at least one transfer channel is at least 1.5 in relation to a stroke of said piston; and,
said crankcase interior defining a crankcase volume including all of said at least one transfer channels being at most 3.1 in relation to a piston displacement.