Kubota Corporation

Kiichiro Yamada

Takahiro Kajihara

Shinkichi Iwasaki

Tsuyoshi Nishida

Cap segment surfaces () and () of a larger-diameter end portion () of a connecting rod () are positioned at an upper and a lower portions of a crank pin () and are inclined from a right upper portion of the larger-diameter end portion () of the connecting rod () to a left lower portion thereof. A cap () is attached by connecting rod bolts () and (), head portion () and () of which are arranged vertically along the inclination direction of the cap segment surfaces () and (). With a piston () existing at a bottom dead center, a weight connection portion () of an upper rotary balancer () is provided with a recess () at a portion oriented leftwards and downwards which comes to face the head portion () of the upper connecting rod bolt ().

Engine

In an inclined engine where a cylinder () projects from a crank case () obliquely and upwardly, when seen in a direction parallel to a center axis () of a crank shaft (), under a specific observation condition in which the cylinder projecting direction is deemed as an upper right side, a valve operating cam gear () meshes with a crank gear () from a horizontal right side of the latter and a governor gear () is arranged in a space defined below a portion where the valve operating cam gear () meshes with the crank gear (). This governor gear () engages with the valve operating cam gear () from a lower left side of the latter.

Inclined engine

Internal combustion engine

In a partially liquid-cooled type forced air-cooling system for an internal combustion engine which includes an air-cooled cylinder and a liquid-cooled cylinder head, a centrifugal cooling fan is provided in front of a crankcase so as to rotate about the fore and rear axis thereof, and a cooling air delivery opening is provided at the back portion of a draft chamber within a fan casing which encircles the cooling fan, so as to orientate throughflow at least to the cylinder. A portion of the encircling wall of the fan casing which is arranged at the side of the cylinder head is provided with an opening. Cylinder is adapted to be cooled adequately by the cooling air flow delivered through the opening and a radiator is adapted to be cooled effectively by the cooling air flow passing through the opening provided in the encircling wall of the fan casing so that at least a portion of the cylinder head can be cooled intensively.

Partially liquid-cooled type forced air-cooling system for internal

In a forced air-cooled engine, a local high temperature portion is adapted to be cooled effectively so that thermal distortion and thermal breakage of a cylinder and/or a cylinder head caused by such a local high temperature can be avoided. To prevent thermal distortion of the engine, there is provided a cylinder jacket, for cooling part of an engine cylinder in a partition wall between the cylinder and its push rod chamber. As means for preventing the thermal distortion of the cylinder head, there is provided a cooling air passage in a cylinder head, and there is also provided a head jacket for oil-cooling around a divided combustion chamber so as to circulate oil through the head jacket and a radiator. Local high temperature portions in the cylinder and/or the cylinder head can thus be oil-cooled effectively.

Growing community of inventors

Sakai, Japan

Kiichiro Yamada