Internal gear-wheel pump comprising reinforced channels

Abstract

The invention relates to a gerotor fuel pump (2) comprising ribs (18, 19), which are located in channels (16, 17) that are configured as inlets and outlets and that are situated in housing parts (8, 9). The ribs (18, 19) are positioned transversely to the maximal extension of the cross-sections of the channels (16, 17), producing a high degree of stability in the channels (16, 17). The housing parts (8, 9) are composed of plastic.

Description

BACKGROUND OF THE INVENTION [0001] The invention relates to a gerotor fuel pump for feeding fuel from a fuel tank of a motor vehicle having a housing, having a rotor pair mounted between two housing parts, and having elongated inlet and outlet ducts arranged in the housing. [0002] Fuel pumps of this type are often used in particular to feed diesel fuel in modern-day motor vehicles, and are known from practice. The rotor pair of the gerotor fuel pump has an inner rotor with external toothing and an outer rotor with internal toothing. Here, the external toothing usually has one tooth more than the internal toothing. The rotational centre of the inner rotor is offset with respect to the rotational centre of the outer rotor. The inlet and outlet ducts are usually arranged in opposing housing parts. As a result, flow passes axially through the fuel pump. [0003] A disadvantage of the known fuel pump is that the elongated inlet and outlet ducts adversely affect the stability of the housing...

AI Technical Summary

Benefits of technology

[0006] With this embodiment, the rib can reinforce the duct and thus prevent the housing from bending in the region of the duct. As a result, the housing has a particularly high stability in the region of the duct. High stability is particularly advantageous at the outlet since high forces act on that region of the housing which has the outlet duct. As a result, bending of the housing in the region of the ducts which is caused by the occurring forces can be eliminated. The housing can be produced from a very thin-walled and cost-effective material as a result. In this way, the fuel pump according to the invention requires no separate reinforcing rings to be mounted, is therefore of particularly simple construction and can additionally be produced particularly cost-effectively.

[0007] A plurality of ribs could, for example, cover the ducts in the manner of a grid. According to another advantageous embodiment of the invention, the number of ribs can be kept particularly low if the at least one rib is arranged transversely with respect to the longest extent of the duct cross section, and connects opposing edges of the housing, which delimit the duct, to one another. In addition, the dimensions and thus a throttling effect of the ribs are kept particularly low as a result.

[0008] The outlay in terms of assembly of the fuel pump according to the invention can be reduced further if the rib is produced in one piece with those regions of the housing which adjoin the ducts.

[0009] The fuel pump according to the invention can be produced particularly cost-effectively if at least one of the housing parts is produced from plastic. The low strength of the plastic housing parts in comparison to the ceramic plates of the known fuel pump is compensated for by the ribs in the ducts.

[0010] According to another advantageous refinement of the invention, the housing parts can be connected with a particularly low structural outlay if the housing parts are screwed to one another, one of the plastic housing parts having receptacles for metal nuts. The metal nuts ensure sufficient stability of the fuel pump according to the invention.

Problems solved by technology

A disadvantage of the known fuel pump is that the elongated inlet and outlet ducts adversely affect the stability of the housing.

The known fuel pump is very costly as a result.

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