A case for an endless transmission member includes a first case member attached to a vehicle-mounted internal combustion engine and a second case member attached to the first case member. The first and second case members define an accommodation chamber that accommodates an endless transmission member looped over rotating bodies of the engine. The first case member includes a communication hole that connects the accommodation chamber to the inside of the engine. The first or second case member includes a guide rib that guides lubricant from the accommodation chamber to the inside of the engine. In an orientation of the case when the engine is installed in a vehicle, the guide rib is provided along part of the lower side of the opening edge of the communication hole including the lower end of the opening edge.

A case for an endless transmission member includes a first case member attached to a vehicle-mounted internal combustion engine and a second case member attached to the first case member. The first and second case members define an accommodation chamber that accommodates an endless transmission member looped over rotating bodies of the engine. The first case member includes a communication hole that connects the accommodation chamber to the inside of the engine. The first or second case member includes a guide rib that guides lubricant from the accommodation chamber to the inside of the engine. In an orientation of the case when the engine is installed in a vehicle, the guide rib is provided along part of the lower side of the opening edge of the communication hole including the lower end of the opening edge.

A sawmill includes a four-stroke internal combustion engine having an output shaft for driving a sawblade. The output shaft has a longitudinal axis. The engine is mounted on the sawmill for rotation between a first operative position with the longitudinal axis of the output shaft extending at a first angle, and a second operative position with the longitudinal axis of the output shaft extending at a second angle transversely to the first angle. The engine has fuel injection to facilitate operation in the first and second operative positions and a lubrication system incorporating a wet sump. An oil pick up for the lubrication system is configured to pick up oil from the wet sump at both the first and second operative positions.

A sawmill includes a four-stroke internal combustion engine having an output shaft for driving a sawblade. The output shaft has a longitudinal axis. The engine is mounted on the sawmill for rotation between a first operative position with the longitudinal axis of the output shaft extending at a first angle, and a second operative position with the longitudinal axis of the output shaft extending at a second angle transversely to the first angle. The engine has fuel injection to facilitate operation in the first and second operative positions and a lubrication system incorporating a wet sump. An oil pick up for the lubrication system is configured to pick up oil from the wet sump at both the first and second operative positions.

An internal combustion engine having an improved oil treatment system. The internal combustion engine may be a splash lubrication engine in which oil is flowed through an oil circulation circuit by a passive pump. In another aspect, a dipstick tube may be provided that includes a portion of the oil circulation circuit. In a further aspect, the internal combustion engine comprises one or more protuberances that automatically penetrate an oil treatment apparatus upon the oil treatment apparatus being mounted to the internal combustion engine, thereby fluidly coupling the oil treatment apparatus to the oil circulation circuit.

An internal combustion engine having an improved oil treatment system. The internal combustion engine may be a splash lubrication engine in which oil is flowed through an oil circulation circuit by a passive pump. In another aspect, a dipstick tube may be provided that includes a portion of the oil circulation circuit. In a further aspect, the internal combustion engine comprises one or more protuberances that automatically penetrate an oil treatment apparatus upon the oil treatment apparatus being mounted to the internal combustion engine, thereby fluidly coupling the oil treatment apparatus to the oil circulation circuit.

A lubricating device for lubricating components includes first and second lubricant guide plates which have respective inclination angles with respect to a horizontal line such that the angle of inclination of the first lubricant guide plate is smaller than that of the second lubricant guide plate. The inclination angle of the first lubricant guide plate is determined to permit the lubricant oil guided by the first lubricant guide plate to be directed into the catcher reservoir, and to inhibit the lubricant oil from being supplied to component or components disposed above the gear, and the inclination angle of the second lubricant guide plate is determined to permit the lubricant oil guided by the second lubricant guide plate to be supplied to the component or components disposed above the gear.

A lubricating device for lubricating components includes first and second lubricant guide plates which have respective inclination angles with respect to a horizontal line such that the angle of inclination of the first lubricant guide plate is smaller than that of the second lubricant guide plate. The inclination angle of the first lubricant guide plate is determined to permit the lubricant oil guided by the first lubricant guide plate to be directed into the catcher reservoir, and to inhibit the lubricant oil from being supplied to component or components disposed above the gear, and the inclination angle of the second lubricant guide plate is determined to permit the lubricant oil guided by the second lubricant guide plate to be supplied to the component or components disposed above the gear.

A gear or engine oil or other type of lubricant, which effectively reduces churning losses in a dip lubrication system or any lubrication system where churning loss occur has a surface tension less than 28 mN/m and viscosity less than 400 mPa-sec at 25 C. (about 500 cSt at 25 C.). Formulations include Group I-IV base oil, in combination with an amount of silicone oil effective to decrease the surface tension of the oil, thereby reducing churning losses. When the base oil is prominently Group III, the coefficient of friction of the gear oil is also reduced.

A gear or engine oil or other type of lubricant, which effectively reduces churning losses in a dip lubrication system or any lubrication system where churning loss occur has a surface tension less than 28 mN/m and viscosity less than 400 mPa-sec at 25 C. (about 500 cSt at 25 C.). Formulations include Group I-IV base oil, in combination with an amount of silicone oil effective to decrease the surface tension of the oil, thereby reducing churning losses. When the base oil is prominently Group III, the coefficient of friction of the gear oil is also reduced.