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: 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: 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 valve structure is disclosed which is mechanically simple and is suited for use in an overhead-valve engine having a hemi-spherical combustion chamber. In the valve structure, inlet valve 3 and exhaust valve 2 are positioned in such a manner that they incline substantially like a "V" in front view to form an acute angle therebetween. Positioned on a first inclined plane U1 are the longitudinal center lines 2a, 4a and 1a of the inlet valve 2, the associated push rod 4 and the associated rocker arm 1, which connects these, respectively. Positioned on a second inclined plane U2 are the longitudinal center lines 3a, 4a and 1a of the exhaust valve 3, the associated push rod 4 and the associated rocker arm 1, which connects these, respectively.

Abstract: A lubrication device for a vertical crank shaft engine. A portion of a crank case, which houses the crankshaft with a small clearance at a given range of the lower side of the crankshaft extending vertically and expands upwards of the housing portion, forms an oil reservoir between the crankshaft, and a pumping member fixed to the crankshaft for rotation is provided in the lower portion of the oil reservoir.

Abstract: An engine having a vertically disposed crankshaft includes an engine cover for closing a whole upper area of an engine body and having a skirt portion protruding downwardly from a periphery of the engine cover, and a cooling fan with a flywheel fixed to an output shaft of the engine below the engine body. The engine further includes a protruded shroud formed integrally on a wall portion of the engine body to completely close an annular clearance between the wall portion and the skirt portion, and a plurality of apertures formed in the protruded shroud to constitute a cooling air intake inlet.