Fuel supply device

1. A fuel supply device that supplies fuel to an internal-combustion engine from a fuel tank for a vehicle, the fuel supply device comprising:

a cover to be attached to an upper wall of the fuel tank;

a pump unit to be disposed on a bottom wall of the fuel tank to pump fuel from the fuel tank toward the internal-combustion engine; and

a connecting strut that connects the cover and the pump unit with each other,

the pump unit includes

a unit body supported by the connecting strut in a radial direction and a thrust direction, and

a fuel pump arranged on the unit body to pump fuel drawn from the fuel tank toward the internal-combustion engine, the center of gravity of the fuel pump being located offset toward the connecting strut than a width center of a width of the unit body, the width being defined from a thrust support part where the unit body is supported by the connecting strut to an end part of the unit body opposite from the connecting strut in a specific transverse direction, wherein:

a subtank is provided on the unit body, and has an inner space to store fuel to be drawn by the fuel pump from the fuel tank,

the subtank has an enlarging part that enlarges the inner space, and

the enlarging part is projected in a remaining space that remains around the fuel pump, on a side opposite from the connecting strut through the width center of the width of the unit body in the specific transverse direction.

2. The fuel supply device according to claim 1 , wherein

the pump unit further has a surface detection unit that detects a height of fuel surface in the fuel tank, and

the surface detection unit is arranged in a remaining space that remains around the fuel pump, on a side opposite from the connecting strut through the width center of the width of the unit body in the specific transverse direction.

3. The fuel supply device according to claim 1 , wherein

the pump unit further has a jet pump that pumps fuel from the fuel tank to the inner space through a diffuser passage in which a pressurization fuel is ejected with operation of the fuel pump, and

the jet pump is arranged in the remaining space that remains around the fuel pump, on a side opposite from the connecting strut through the width center of the width of the unit body in the specific transverse direction.

4. The fuel supply device according to claim 3 , wherein

the subtank has an inflow part into which the fuel pumped by the jet pump flows from an exit of the diffuser passage, and a guide part that guides fuel overflowing from an upper opening of the inflow part to the inner space, the inflow part being shaped in a based cup,

the guide part forms an open hole open to the fuel tank at a position upper than the upper opening, and

the fuel pump has a discharge pore for discharging vapor fuel drawn during operation at a position lower than the upper opening.

5. The fuel supply device according to claim 3 , wherein

the jet pump has a throat part that forms the diffuser passage,

a center line of an outer diameter of the fuel pump is along the bottom wall, and offset toward the connecting strut from the width center of the width of the unit body in the specific transverse direction, and

a center line of an inner diameter of the throat part is along the bottom wall and the center line of the outer diameter of the fuel pump, and is located on a side opposite from the connecting strut through the width center of the width of the unit body in the specific transverse direction.

6. The fuel supply device according to claim 1 , wherein

a center line of an outer diameter of the fuel pump is along the bottom wall, and offset toward the connecting strut from the width center of the width of the unit body in the specific transverse direction.