The present disclosure describes an oil pan structure including a storing portion that stores oil for an internal combustion engine. The storing portion includes a shallow bottom portion, a deep bottom portion deeper than the shallow bottom portion, and a connection surface that connects the shallow bottom portion and the deep bottom portion between the shallow bottom portion and the deep bottom portion. A side wall is formed at a position facing the connection surface with the shallow bottom portion interposed between the side wall and the connection surface. A rib is formed on a back surface of the shallow bottom portion so as to extend from one side or another side of the side wall in a width direction of the shallow bottom portion toward an end portion of the connection surface on an opposite side in the width direction.

To achieve an improved rigidity, the an oil pan (3) for forming a lower end part of an internal combustion engine (1) comprises a bottom wall (6) and a side wall (7) extending from a peripheral edge of the bottom wall, wherein the bottom wall includes a pair of first planar surface portions (35) extending in a lateral direction and provided on either end of the bottom wall with respect to a fore and aft direction orthogonal to the lateral direction, and a curved surface portion (36) recessed downward with respect to the first planar surface portions.

A cooling system for an outboard motor of a marine vessel is provided. The cooling system includes an oil sump housing having an inner housing wall and an outer housing wall. The inner housing wall defines a transmission mounting cavity, and the inner housing wall and the outer housing wall defines an oil containment cavity that at least partially surrounds the transmission mounting cavity. The cooling system further includes a first sprayer nozzle and a second sprayer nozzle. Both the first sprayer nozzle and the second sprayer nozzle are coupled to the oil sump housing and configured to spray cooling fluid within the transmission mounting cavity onto an inner surface of the inner housing wall.

An oil pan assembly including a first portion having an inner set of openings configured to receive a first set of fasteners to couple the first portion to an engine block and a second portion having an outer set of openings positioned laterally outward relative to the inner set of openings and configured to receive a second set of fasteners to couple the second portion to the first portion and the engine block.

A power unit having a crankcase and peripheral devices wherein a driving source for a gear shifting device is disposed so as to be displaced below the crankcase. An engine includes a gear speed change mechanism having a plurality of gear pairs for changing the speed of a rotational force of a crankshaft. A gear shifting device includes at least a plate-shaped shift arm rocking about a shift spindle to perform a gear pair changing operation on the gear speed change mechanism. A crankcase houses the gear speed change mechanism and the gear shifting device with an oil pan attached to a lower portion of the crankcase. A communicating hole communicating with the oil pan is formed in a bottom portion of the crankcase with the bottom portion being located below the shift arm, and a rocking range of the shift arm partly overlaps the communicating hole.

A fluid sump for accommodating a lubricating fluid and transmission housing for a vehicle comprising such a fluid sump. The fluid sump may comprise a first compartment for collecting the lubricating fluid, a second compartment in which the lubricating fluid can be brought in contact with a rotating member, and an intermediate compartment having a first opening for introducing the lubricating fluid from the first compartment into the intermediate compartment, a second opening for introducing the lubricating fluid from the intermediate compartment into the second compartment, and a floating element. In one or more examples, the first opening can be opened and closed by the floating element, and the first compartment, the intermediate compartment and the second compartment are provided with ambient pressure.

In a power unit device of a vehicle in which a differential device is arranged on one side of an engine, warming-up of the engine is facilitated while heat convection from an oil pan to a differential housing is inhibited. The power unit device includes a heat insulating member that covers the outer side of an oil pan, and a differential housing that is fitted to and mounted on the oil pan. A fitting portion is provided in the differential housing, and a fitted portion is provided in the oil pan. A fitting face portion of one of the fitting portion and the fitted portion includes, at different positions in the circumferential direction, a plurality of recesses and projections in the radial direction, and is fitted to a fitting face portion of the other of the fitting portion and the fitted portion by the plurality of projections.

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.

An agricultural vehicle transmission may comprise a housing comprising a bulkhead where the bulkhead may divide the housing into a sump and a reservoir. The bulkhead may comprise an opening configured to fluidly couple the sump and the reservoir. A plurality of transmission gears may be disposed in the reservoir of the housing. The opening in the bulkhead may balance the vehicle transmission system to remove excess oil in the sump and away from the plurality of transmission gears.

A cooling system for an outboard motor of a marine vessel is provided. The cooling system includes an oil sump housing having an inner housing wall and an outer housing wall. The inner housing wall defines a transmission mounting cavity, and the inner housing wall and the outer housing wall defines an oil containment cavity that at least partially surrounds the transmission mounting cavity. The cooling system further includes a first sprayer nozzle and a second sprayer nozzle. Both the first sprayer nozzle and the second sprayer nozzle are coupled to the oil sump housing and configured to spray cooling fluid within the transmission mounting cavity onto an inner surface of the inner housing wall.