Abstract: An internal gear pump (39) of the present invention includes an inner rotor (49) relatively non-rotatably mounted on one end of a pump shaft (22) driven by a crankshaft (9), and an outer rotor (50) rotatably supported by a crankcase (1) and meshed with the inner rotor (49). The pump shaft (22) has a flange (47) formed therein, which flange (47) is rotatably supported by the crankcase (1) and covers one end face of each of the inner and outer rotors (49 and 50).

Abstract: A mounting structure for an air cleaner on a combustion engine according to the present invention includes an engine cover (9) for covering at least a portion of the combustion engine (E). The cover (9) includes an air cleaner casing (81) having an opening and an air cleaner cover (83) for covering the opening of the air cleaner casing (81). Flanges (81f, 83f) are formed in respective joint portions of the air cleaner casing (81) and the air cleaner cover (83). The mounting structure also includes a slider (10) movable between a disengagement position and an engagement position in a direction parallel to the joint portions. This slider (10) when moved to the engagement position connects the flanges (81f, 83f) of the air cleaner casing (81) and cover (83), but when moved to the disengagement position the slider (10) enables the cover (83) to be released from the casing (81).

Abstract: A combustion engine according to the present invention has a unitary fan-pulley assembly (F), in which a cooling fan (8) and a starter pulley (9) are formed integrally with each other. The cooling fan (8) is fixed to a crankshaft (1). The pulley (9) receives a starting force when engaged with engagement pawls 14b integral with a recoil starter (14). A bracket (11) is fixedly mounted on the crankshaft (1) together with the unitary fan-pulley assembly (F) for urging engagement grooves (92), each defined between neighboring engagement projections (91) of the starter pulley (9), in an axial direction of the unitary fan-pulley assembly (F).

Abstract: A breathing system in a combustion engine includes an air cleaner (3) for purifying air to be supplied to the engine. The air cleaner (3) includes a cleaner casing (30) having a blow-by gas inlet port (33) and an intake air discharge port (34). The breathing system also includes a breather passage (8) having first and second breather passage portions. The first breather passage portion is fluidly connected with the inlet port (33) for communicating a crank chamber (1a) to a portion of an interior of the air cleaner (3) downstream of the cleaner element (50). The second breather passage portion fluidly connects the blow-by gas inlet port (33) and the intake air discharge port (34) and has a drain hole (95) for draining into the cleaner casing (30) a water component, separated from a blow-by gas (G) flowing through the breather passage (8).

Abstract: To provide an internal combustion engine of a vertical shaft type, in which leakage of an oil from a crankcase and an oil pan is effectively prevented, which has high mounting rigidity relative to a working machine and, also, which is capable of being easily serviced, the combustion engine includes a vertically extending crankshaft (9) having a pair of upper and lower crank webs (14A and 14B), a crankcase (1) accommodating the crankshaft (9) and including an oil pan (2), and a crankcase cover (3) mounted on an upper surface (1a) of the crankcase (1) to cover the crankcase (1). The upper surface (1a) of the crankcase (1) is positioned above the upper crank web (14A).

Abstract: A breathing system in a combustion engine includes an air cleaner (3) for purifying air to be supplied to the engine. The air cleaner (3) includes a cleaner casing (30) having a blow-by gas inlet port (33) and an intake air discharge port (34). The breathing system also includes a breather passage (8) having first and second breather passage portions. The first breather passage portion is fluidly connected with the inlet port (33) for communicating a crank chamber (1a) to a portion of an interior of the air cleaner (3) downstream of the cleaner element (50). The second breather passage portion fluidly connects the blow-by gas inlet port (33) and the intake air discharge port (34) and has a drain hole (95) for draining into the cleaner casing (30) a water component, separated from a blow-by gas (G) flowing through the breather passage (8).

Abstract: A mounting structure for an air cleaner on a combustion engine according to the present invention includes an engine cover (9) for covering at least a portion of the combustion engine (E). The cover (9) includes an air cleaner casing (81) having an opening and an air cleaner cover (83) for covering the opening of the air cleaner casing (81). Flanges (81f, 83f) are formed in respective joint portions of the air cleaner casing (81) and the air cleaner cover (83). The mounting structure also includes a slider (10) movable between a disengagement position and an engagement position in a direction parallel to the joint portions. This slider (10) when moved to the engagement position connects the flanges (81f, 83f) of the air cleaner casing (81) and cover (83), but when moved to the disengagement position the slider (10) enables the cover (83) to be released from the casing (81).

Abstract: An internal gear pump (39) of the present invention includes an inner rotor (49) relatively non-rotatably mounted on one end of a pump shaft (22) driven by a crankshaft (9), and an outer rotor (50) rotatably supported by a crankcase (1) and meshed with the inner rotor (49). The pump shaft (22) has a flange (47) formed therein, which flange (47) is rotatably supported by the crankcase (1) and covers one end face of each of the inner and outer rotors (49 and 50).

Abstract: A combustion engine according to the present invention has a unitary fan-pulley assembly (F), in which a cooling fan (8) and a starter pulley (9) are formed integrally with each other. The cooling fan (8) is fixed to a crankshaft (1). The pulley (9) receives a starting force when engaged with engagement pawls 14b integral with a recoil starter (14). A bracket (11) is fixedly mounted on the crankshaft (1) together with the unitary fan-pulley assembly (F) for urging engagement grooves (92), each defined between neighboring engagement projections (91) of the starter pulley (9), in an axial direction of the unitary fan-pulley assembly (F).

Abstract: To provide an internal combustion engine of a vertical shaft type, in which leakage of an oil from a crankcase and an oil pan is effectively prevented, which has high mounting rigidity relative to a working machine and, also, which is capable of being easily serviced, the combustion engine includes a vertically extending crankshaft (9) having a pair of upper and lower crank webs (14A and 14B), a crankcase (1) accommodating the crankshaft (9) and including an oil pan (2), and a crankcase cover (3) mounted on an upper surface (1a) of the crankcase (1) to cover the crankcase (1). The upper surface (1a) of the crankcase (1) is positioned above the upper crank web (14A).