A fuel pump system of a hybrid vehicle is provided. The fuel pump system prevents a fuel pump from continuing to operate when fuel is exhausted, whereby the fuel pump may be damaged. The pressure of fuel is measured in response to exhaustion of fuel, and when the pressure of fuel is low, fuel is circulated within the fuel pump instead of being supplied to the engine side, thereby preventing the fuel pump from being stuck due to frictional heat.

A fuel tank includes: a tank body including a bottom wall, a lateral wall and an upper wall, the tank body storing fuel in an interior surrounded by the bottom wall, the lateral wall and the upper wall; and a sub-tank storing a part of the fuel, the sub-tank including a wall portion, an opening portion and a post portion, the wall portion standing on the bottom wall and extending toward the upper wall. The opening portion is provided in the wall portion and is a portion in which the fuel flows. The post portion is provided integrally with the wall portion. The post portion is extended along a height direction of the wall portion from the bottom wall and is joined to the bottom wall and the upper wall.

A fuel tank for a vehicle is formed of a tank main body in which an upper tank and a lower tank are mutually joined to form a closed space in which fuel is housed, and a sub-tank fixed to a bottom surface part of the lower tank by spot welding, in which a plurality of rows of the spot welding are set along a longitudinal direction of the lower tank with an interval therebetween in a width direction of the sub-tank, at least one bead positioned between the rows of the spot welding and extending continuously along the longitudinal direction of the lower tank is formed on the bottom surface part of the lower tank, and a lower surface of the sub-tank has no portion that is not brought into contact with the bottom surface part of the lower tank except for the bead.

In a method for operating a fuel tank system for a motor vehicle, with the fuel tank system having a fuel tank and an accumulation tank to which a suction side of a fuel pump is connected, at least one sensor determines a geodetic orientation of the fuel tank when a fill level of the fuel tank is below a predetermined minimum fill level. A fueling parameter is read out from a characteristic curve field based on the geodetic orientation, and the fueling parameter is displayed by a signaling device.

An unmanned aerial vehicle has an internal combustion engine, and a fuel and lubrication system comprising a fuelling system for fuelling the engine and a lubrication system for delivering lubricating oil to the engine. The fuelling system comprises a fuel reservoir from which fuel can be delivered to the engine. The fuel reservoir comprises a main tank and a header tank. The lubrication system comprises an oil tank. The oil tank is accommodated internally within the main tank to provide an integrated assembly. The arrangement provides for warming of lubrication oil for the UAV engine using several available heat sources. Further, the arrangement facilitates a configuration and layout intended to minimise or negate any undesirable moments of inertia for the UAV during flight as fuel and oil is consumed.

In a fuel collection device for a fuel tank in a motor vehicle, a swirl pot is connected, by a catching connection and a locking connection, to a holding element mounted in the fuel tank. The catching connection, along with a supporting element, allows the swirl pot to be secured in a plane. The locking connection retains the swirl pot on the holding element. A sliding element allows the locking connection to be blocked.

A swirling wall structure-extends from a lower side toward an upper side in a sub-tank, and a fuel flow, which is outputted into an inside of the sub-tank from a flow outlet of a diffuser passage opened toward a lateral side, is swirled by the swirling wall structure. The swirling wall structure-includes a curved wall surface and a U-turn wall surface. The curved wall surface is curved about a longitudinal axis, which extends from the lower side toward the upper side in the sub-tank, to bend the fuel flow outputted from the flow outlet. The U-turn wall surface extends continuously from the curved wall surface to make a U-turn of the fuel flow, which is bent by the curved wall surface.

A fuel pump system of a hybrid vehicle is provided. The fuel pump system prevents a fuel pump from continuing to operate when fuel is exhausted, whereby the fuel pump may be damaged. The pressure of fuel is measured in response to exhaustion of fuel, and when the pressure of fuel is low, fuel is circulated within the fuel pump instead of being supplied to the engine side, thereby preventing the fuel pump from being stuck due to frictional heat.

Methods and systems are described for a fuel system in an engine comprising two lift pumps. One example method comprises deactivating one of a first lift pump and a second lift pump if fuel fill level in a common reservoir decreases below a threshold fill level, wherein the first lift pump and the second lift pump are positioned in the common reservoir. By deactivating one of the two lift pumps, the two lift pumps may be protected from degradation due to fuel starvation.

A baffle for use in a fuel tank has a sidewall and an interior space. The sidewall is formed of a flexible material so as to be radially compressible. The compressibility of the sidewall allows the baffle to be inserted through a hole which is smaller in diameter than the uncompressed diameter of the baffle. The baffle is preferably also longitudinally compressible so that it can be mounted in fuel tanks of varying depths.