An oil structure of an internal combustion engine includes a main oil pump configured to suck lubricating oil stored in a crankcase and feed the lubricating oil to respective engine parts and a scavenge pump configured to recover the lubricating oil from any lubricated engine part and return the lubricating oil into the crankcase. The scavenge pump has: an oil suction passage extending from the lubricated engine part to a suction side of the scavenge pump; and an air introduction passage for negative pressure control connected to the oil suction passage. An air introduction port of the air introduction passage is open to the inside of the crankcase and is set to a height position such that, when a level of the lubricating oil in the crankcase is inclined, the lubricating oil flows in from the air introduction port and returns from the scavenge pump into the crankcase.

A system is provided. The system includes a reciprocating engine configured to consume oil at or less than 0.25 g/kw-hr and to use makeup oil. The reciprocating engine includes an engine oil sump. The system is configured to maintain an oil volume in the reciprocating engine during operation so that a residence time of oil in the reciprocating engine is at or less than 1000 hours.

A device for reciprocatingly removing and replenishing fluid in circulating system of an hydraulic mechanism that includes at least two processing tanks, at least one air pressure regulator and connector releasably engageable with a pressurized air source, at least one vacuum generator, at least one pressure regulator; and means for removing the fluid from the circulating system at vacuum.

An air introduction hole having an aperture area smaller than that of an oil inlet is formed above the oil inlet, and therefore, when the oil level of oil accumulated in an oil pan inclines during traveling, air is sucked in through the air introduction hole, thereby restraining a decrease in hydraulic pressure of the oil. Further, the air introduction hole is formed behind the oil inlet in the vehicle front-rear direction in a vehicle. Accordingly, during heavy load traveling such as hill-climbing traveling, the air introduction hole sinks in the oil, thereby restraining the air from being sucked in through the air introduction hole. Accordingly, no air is sucked into an oil strainer, thereby making it possible to obtain high hydraulic pressure during heavy load traveling.

An engine mounting assembly includes a front frame element defining, in part, a structural load bearing assembly, a differential case mounted to the frame at a frame mounting area, and an oil pan having upright and bottom walls defining an oil sump. The differential case has an opening configured to receive an axle assembly and has walls defining a pan-receiving recess. The oil pan is configured to conform to the pan-receiving recess to be supported by the differential case and overlap the frame mounting area. The oil pan has a mounting flange extending from the upright walls and mounting bores that receives mounting bolts for coupling the oil pan to the engine and the oil pan to the differential case. The differential case and the oil pan form part of the structural load bearing assembly of the work vehicle to transfer structural loads to and from the front frame element.

A lubrication system for an internal combustion engine of a work vehicle includes an engine oil sump and a pump unit fluidly connected to the engine oil sump to receive engine oil therefrom. The pump unit, in turn, includes a first oil pump comprising a variable displacement pump, a second oil pump, a drive line mechanically coupled to the first oil pump and the second oil pump that drives each of the pumps, and a manifold that directs engine oil from the engine oil sump to the first and second oil pumps. A first oil circuit is fluidly coupled to the first oil pump to direct a first flow of engine oil to piston spray jets in the engine and a second oil circuit is fluidly coupled to the second oil pump to direct a second flow of engine oil to one or more oiled engine components in the engine.

A lubrication system for a mechanical system, the lubrication system comprising a main tank, a reserve tank and a main lubrication circuit. The main lubrication circuit comprises, in particular, a pump drawing in the lubricating liquid from the main tank via a main suction point and a main suction pipe connecting the main suction point to the pump. The reserve tank is supplied with lubricating liquid either directly from the main tank or via the main lubrication circuit. The reserve tank is connected to the main suction pipe via an outlet pipe and the reserve tank is located above the main suction point so that the lubricating liquid flows through the outlet pipe to the main suction pipe by gravity.

An internal combustion engine unit including an internal combustion engine body, a balancer device attached to a lower portion of the internal combustion engine body, and an oil pan attached to the lower portion of the internal combustion engine body so as to surround the balancer device. The balancer device is disposed facing an outlet of an oil outflow hole, and the oil outflow hole is formed in the internal combustion engine body so as to return a lubricating oil in the internal combustion engine body to the oil pan.

A drain tube device that includes a first tubular region, a second region and arcuate tubular region interposed between the first tubular region and the second region. In certain embodiments, the arcuate region is contiguously joined to the first tubular and the second region such that the first tubular region and the second region form an acute angle in a first plane that is between 45° and 90°. The second region has an end distal to the arcuate tubular region and includes a longitudinal opening defined in at least a portion of the region between the arcuate tubular region and the distal end. In certain embodiments, the arcuate region can also have a configuration that provides an angle located out of the first plane between the first tubular region and the second region that is between zero and 90°.

The oil storage structure includes an oil pan that closes a lower opening of the transmission case and forms an oil pool in a lower space inside the transmission case, and a strainer having a suction port for oil located in the oil pool. The suction port for the oil is provided so as to face a bottom wall portion of the oil pan with a gap in between, and the bottom wall portion of the oil pan is provided with a protruding portion protruding toward the suction port, with the protruding portion being formed in a direction across the suction port as viewed from the bottom wall portion.