Abstract: A work apparatus has an internal combustion engine. The internal combustion engine includes a crankcase in which a crankshaft is mounted rotatably about an axis of rotation. The work apparatus includes a fan spiral and a fan wheel arranged in the fan spiral for conveying cooling air for the internal combustion engine. A cylinder is arranged on the crankcase, and the cylinder includes a first outer side facing the fan wheel and a second outer side facing away from the fan wheel. The fan spiral has a first outlet opening for a first cooling air flow for cooling the first outer side of the cylinder. The fan spiral has a second outlet opening for a second cooling air flow for cooling the second outer side of the cylinder.

Abstract: A two-stroke engine has a cylinder with a combustion chamber which is bounded by a piston which drives a crankshaft which rotates in a crankcase. The crankcase is connected to the combustion chamber via an overflow passage in the lower dead center region of the piston. The two stroke engine has an intake passage. A carburetor forms a section of the intake passage. The intake passage is partially divided into an air passage, which supplies combustion air into an overflow passage, and a mixture passage which opens into the crankcase. A throttle valve mounted pivotably in the carburetor controls the combustion air quantity supplied to the air and mixture passages. An air-guiding element arranged on the passage wall of the air passage guides the combustion air passing between the throttle valve and passage wall in the idling position of the throttle valve in the direction of the mixture passage.

Abstract: An engine has a cylinder wherein a reciprocating piston is mounted. The piston drives, via a connecting rod (6), a crankshaft (7) pivotably mounted in a crankcase. The connecting rod is connected to the piston via a piston pin. An inlet window for combustion air is provided and controlled by the piston. The piston separates a combustion chamber from the crankcase interior space and has a piston base the underside of which is oriented toward the crankcase. To achieve good cooling of the piston and of the piston pin bearing, a first flow-guide element is provided within the crankcase interior space adjacent to the inlet window. The first flow-guide element redirects the combustion air flowing in through the inlet window in the direction of the underside of the piston base.

Abstract: A two-stroke engine, comprising: a crankcase; a cylinder connected to said crankcase; a combustion chamber defined by a reciprocally mounted piston within said cylinder; a crankshaft mounted rotatably in said crankcase and drivingly connected with said piston; at least one overflow passage connecting the crankcase and the combustion chamber when the piston is positioned in the lower dead center region; a connecting stub attached to said cylinder which contains an intake passage that opens into the crankcase and supplies fuel and combustion air, said intake passage including therein an air-fuel mixture passage, wherein said connecting stub contains at least one section of the mixture passage; at least one fuel opening for supplying fuel into said mixture passage; and a guiding rib positioned within said connecting stub and oriented longitudinally in the mixture passage and protruding into the mixture passage.

Abstract: An engine has a cylinder wherein a reciprocating piston is mounted. The piston drives, via a connecting rod (6), a crankshaft (7) pivotably mounted in a crankcase. The connecting rod is connected to the piston via a piston pin. An inlet window for combustion air is provided and controlled by the piston. The piston separates a combustion chamber from the crankcase interior space and has a piston base the underside of which is oriented toward the crankcase. To achieve good cooling of the piston and of the piston pin bearing, a first flow-guide element is provided within the crankcase interior space adjacent to the inlet window. The first flow-guide element redirects the combustion air flowing in through the inlet window in the direction of the underside of the piston base.

Abstract: A two-stroke engine has a cylinder with a combustion chamber which is bounded by a piston which drives a crankshaft which rotates in a crankcase. The crankcase is connected to the combustion chamber via an overflow passage in the lower dead centre region of the piston. The two stroke engine has an intake passage. A carburetor forms a section of the intake passage. The intake passage is partially divided into an air passage, which supplies combustion air into an overflow passage, and a mixture passage which opens into the crankcase. A throttle valve mounted pivotably in the carburetor controls the combustion air quantity supplied to the air and mixture passages. An air-guiding element arranged on the passage wall of the air passage guides the combustion air passing between the throttle valve and passage wall in the idling position of the throttle valve in the direction of the mixture passage.

Abstract: A two-stroke engine, comprising: a crankcase; a cylinder connected to said crankcase; a combustion chamber defined by a reciprocally mounted piston within said cylinder; a crankshaft mounted rotatably in said crankcase and drivingly connected with said piston; at least one overflow passage connecting the crankcase and the combustion chamber when the piston is positioned in the lower dead center region; a connecting stub attached to said cylinder which contains an intake passage that opens into the crankcase and supplies fuel and combustion air, said intake passage including therein an air-fuel mixture passage, wherein said connecting stub contains at least one section of the mixture passage; at least one fuel opening for supplying fuel into said mixture passage; and a guiding rib positioned within said connecting stub and oriented longitudinally in the mixture passage and protruding into the mixture passage.