Patent Number: 6,293,243

Title: Short-stroke internal combustion engine

Abstract: An internal combustion engine for a work tool has a cylinder with a combustion chamber. A piston is reciprocatingly mounted in the cylinder and delimits the combustion chamber. The crankshaft has bearing pins and at least one crank web. The bearing pin has a mounting end, and the crank web has a first receiving bore and a second receiving bore. The mounting end of the bearing pin is mounted in the first receiving bore. A crankcase is provided in which the crankshaft is rotatably mounted by the bearing pins. The crankshaft has a crank pin with a mounting end that is mounted in the second receiving bore of the crank web. A connecting rod has a first end connected to the piston and a second end connected to the crank pin. The crank pin has a longitudinal center axis and the crankshaft has an axis of rotation extending parallel to the longitudinal center axis. The longitudinal center axis and the axis of rotation are spaced at a stroke spacing from one another. The stroke spacing is identical to or smaller than the sum of the bearing pin radius of the mounting end of the bearing pin and a crank pin radius of the mounting end of the crank pin. The bearing pin radius and the crank pin radius are measured in the plane of the crank web.

Inventors: Koder; Ingo (Stuttgart, DE), Otterbach; Horst (Waiblingen, DE), Brunner; Michael (Remshalden, DE)

Assignee: Andreas Stihl AG & Co.

International Classification: F02B 75/16 (20060101); F02B 75/00 (20060101); F02B 63/02 (20060101); F02B 63/00 (20060101); F02B 75/02 (20060101); F02B 075/06 (); F02B 075/32 ()

Expiration Date: 09/25/2018