A fuel pump unit comprising a housing part ( 4 ) arranged between an electric motor ( 2 ) and a fuel pump ( 3 ). The housing part is provided with expansion joints for compensating thermal expansions or swelling of the material of the housing part ( 4 ). The gap between the impeller ( 6 ) and the housing parts ( 4, 5 ) of the fuel pump ( 3 ) can be kept constant by virture of the expansion joints, whereby the fuel pump ( 3 ) is essentially prevented from jamming especially when it runs dry.
1. A fuel feed unit for a motor vehicle, comprising:
a fuel pump which is driven by an electric motor;
a first housing part and a second housing part; and
a rotor arranged between the first and second housing parts, the rotor of the fuel pump being fastened in a rotationally fixed manner to a shaft of the electric motor;
wherein at least one of the first and second housing parts forms a bearing shell for directly mounting the shaft and forms an expansion joint which is configured to expand due to heat generated by the fuel feed unit.
2. The fuel feed unit as claimed in claim 1 , wherein at least one of the first and second housing parts is produced from plastic.
3. The fuel feed unit as claimed in claim 1 , wherein the first housing part faces toward the electric motor includes a radial section which extends toward the shaft of the electric motor and includes an axial section which extends away from the rotor in a direction parallel to the shaft.
4. The fuel feed unit as claimed in claim 3 , wherein the expansion joint is arranged on the axial section near the rotor and comprises a spacing of the first housing part from the shaft of the electric motor.
5. The fuel feed unit as claimed in claim 3 , wherein the expansion joint extends over approximately half of the axial section.
6. The fuel feed unit as claimed in claim 3 , wherein the expansion joint on the axial section extends over an entire height of the radial section.
7. The fuel feed unit as claimed in claim 3 , wherein the expansion joint is arranged in a corner region at which the axial and radial sections adjoin one another.
8. The fuel feed unit as claimed in claim 3 , wherein the expansion joint is arranged on a side of the first housing part facing toward the electric motor which faces away from the rotor.
9. The fuel feed unit as claimed in claim 3 , wherein the expansion joint comprises a groove which extends around an entire circumference of the axial section.
10. The fuel feed unit as claimed in claim 3 , wherein the axial section and the radial section are produced in one piece.