Multi-Piston Pump

Abstract

The present invention relates to a multi-piston pump comprising a housing, a first pump unit having a plurality of piston pumps for the pressure supply of a first pressure circuit, a second pump unit having a plurality of piston pumps for the pressure supply of a second pressure circuit, a drive and an eccentric unit having a first eccentric and a second eccentric, wherein the first and the second eccentrics drive the plurality of piston pumps, and wherein the first and second pump units comprise in each case at least one piston pump which can be driven by the first eccentric and one piston pump which can be driven by the second eccentric. In that in each case, one piston pump which is driven by the first eccentric is arranged parallel to a piston pump which is driven by the second eccentric.

Description

PRIOR ARTDisclosure of the Invention[0001]The present invention relates to a multi-piston pump as generically defined by the preamble to claim 1.[0002]One such multi-piston pump is known for instance from German Patent Disclosure DE 101 53 834 A1. Such multi-piston pumps are used in motor vehicles, for instance, for building up the pressure in brake systems. The known multi-piston pump has two eccentrics, which are located in series and each drive three piston pumps. The piston pumps are disposed in two parallel planes at the level of the eccentrics. The piston pumps, each associated with an eccentric, are disposed at different angles to one another around the eccentric. To avoid pressure pulsations, two piston pumps of the first eccentric are connected to a piston pump of the second eccentric, and two piston pumps of the second eccentric are connected to a piston pump of the first eccentric. The eccentrics are disposed rotated by an angle of approximately 150° to one another. Howev...

AI Technical Summary

Benefits of technology

[0005]Preferably, the first and second pump units include three piston pumps each. The piston pumps are preferably each disposed at an angle of 120° on the first and second eccentrics.

[0006]A further advantage is that the two brake circuits can now be embodied hydraulically symmetrically as well, which further facilitates production. Since the multi-piston pumps of the invention are preferably used in vehicles and are therefore mass-produced products, disposing the piston pumps parallel according to the invention results in potentially great cost reductions.

[0007]Also preferably, the first eccentric and the second eccentric are disposed rotated to one another at an angle. The angle is especially preferably approximately 150°.

[0008]To obtain an especially compact arrangement and to achieve the shortest possible line course in the housing of the multi-piston pump, the piston pumps of the first pump unit are disposed in a first half of the multi-piston pump, and the piston pumps of the second pump unit are disposed in a second half of the multi-piston pump.

[0009]The piston pumps of a pump unit are especially preferably disposed in one half in an angular range of approximately 120°. This makes for a very compact construction.

Problems solved by technology

However, it has been proved in this respect that on the one hand the production effort and expense for such a multi-piston pump are quite high, since many low- and high-pressure lines have to be accommodated in the same housing.

Moreover, the disposition of the piston pumps leads to non-uniform mechanical forces on a bearing of the motor and of the eccentric shaft.

Moreover, the solution to this problem as proposed in this reference has the disadvantage that the hydraulic lengths of the bores of the first and second brake circuit differ, so that there are different pressure buildup times in the multi-piston pump.

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