Patent Application
20150267705
This application claims priority to German Patent Application No. 10 2014 204 946.6, filed Mar. 18, 2014, the contents of which are hereby incorporated by reference in their entirety.
The present invention relates to a pump arrangement comprising a pendulum-slide cell oil pump and a vacuum pump.
In modern motor vehicles, the installation space available in the in the engine compartment is often the limiting factor so that research is increasingly focused on developing compact components such as, for example, pumps.
The present invention is therefore concerned with the problem of providing a pump arrangement that is designed to be particularly compact.
This problem is solved according to the invention by the subject matter of the independent claims. Advantageous embodiments are subject matter to the dependent claims.
The present invention is based on the general idea of no longer designing two pumps separately and accommodating them at separate installation locations in the engine compartment, as required in modern motor vehicles, but rather combining them in a pump arrangement according to the invention, that is, mounting them in a common housing and driving them by a common shaft. In this case, the two combined pumps are designed as a pendulum-slide cell oil pump and a low-pressure pump, for example for a brake system of the motor vehicle. Also, by driving both pumps by a common shaft, only one drive unit is required, as a result of which not only the required installation space can be significantly reduced, but it is also possible to eliminate an additional second drive unit, for example an electric motor, resulting in considerable cost advantages.
Advantageously, the low-pressure pump is designed as a vacuum pump or a rotary vane pump and has a rotor made of plastics. Such a rotor from plastics can be produced in high quality and in a comparatively cost-effective manner, wherein, moreover, plastic materials have a significantly lower weight compared with a construction from metal so that installing the pump arrangement according to the invention in a motor vehicle helps in particular to reduce fuel consumption and therefore also pollutant emissions.
Advantageously, the pendulum-slide cell oil pump and the vacuum pump are arranged coaxially. The construction is similar to an exhaust gas turbocharger, wherein the pendulum-slide cell oil pump is arranged on the one side and the vacuum pump is arranged on the opposing other side. Between both of them, a mounting housing or generally a housing of the pump arrangement is arranged, in which housing the shaft and thus also the inner rotor of the pendulum-slide cell oil pump and the rotor of the rotary vane pump, that is, of the vacuum pump, is mounted. Theoretically, the shaft could additionally be mounted in a vacuum pump cover or the pendulum-slide cell oil pump cover located opposite the mounting housing; however, this is not absolutely necessary so that mounting the shaft can generally be carried out exclusively in the mounting housing.
Advantageously, the rotor is injection molded on the shaft and has a transverse groove in which a vane of the vacuum pump, which is designed as a rotary vane pump, is supported in a sliding manner. By injection molding the rotor of the vacuum pump directly on the shaft, the mounting process of the pump arrangement can be significantly simplified. Theoretically, the shaft can have a projecting or non-round outer contour on the circumferential outer surface thereof, whereby a positive-locking connection between the rotor and the shaft can be achieved. As an alternative to directly injection molding the rotor on the shaft, it is also conceivable to provide a metallic adaptor piece so that in this case, the rotor is connected to the metallic adaptor piece via a positive-locking connection and the adaptor piece, in turn, is connected to the shaft in a rotationally fixed manner. Through this, wear-related replacement of the rotor of the vacuum pump is possible in a comparatively simple manner.
In another advantageous embodiment of the invention, a coupling is arranged on the shaft, which coupling permits separating the pendulum-slide cell oil pump and the vacuum pump. Such a coupling thus enables connecting or disconnecting the vacuum pump as needed. Usually, the pendulum-slide cell oil pump is mechanically driven and the vacuum pump is driven via the latter or the shaft. By providing a coupling between the pendulum-slide cell oil pump and the vacuum pump, the latter can be connected or disconnected as needed and can also be adapted with regard to its capacity, which is carried out by partially closing or opening the coupling, for example.
Further important features and advantages of the invention arise from the sub-claims, from the drawings, and from the associated description of the figures based on the drawings.
It is to be understood that the above-mentioned features and the features still to be explained hereinafter are usable not only in the respective mentioned combination, but also in other combinations or alone, without departing from the context of the present invention.
Preferred exemplary embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein identical reference numbers refer to identical or similar or functionally identical components.
In the figures, schematically:
According to the
When viewing the vacuum pump 3, it can be seen that the vacuum pump is designed as a rotary vane pump or vane pump having only a single vane 12. The vane 12 is displaceably mounted in a rotor 14 having a transverse groove 13. The rotor 14, in turn, is preferably made from plastics and therefore can be produced not only in a cost-effective manner, but at the same time also in high quality. The vacuum pump 3 is closed by a cover 11′ which, for example, is also made from a plastic material, in particular a thermoset or thermoplastic. The rotor 14 can be injection molded directly on the shaft 4 or on a metallic adaptor piece 15 (cf.
With the pump arrangement 1 according to the invention, it is possible to not only significantly reduce the installation space compared with two pumps which up to now are produced separately, but it is also possible to achieve a functional integration associated with the resulting cost advantages. Moreover, friction loss can also be reduced since for the rotor 14 of the vacuum pump 3 as well as for the inner rotor 6 of the pendulum-slide cell oil pump 2, the shaft 4 has to be mounted only in the housing 5, that is, in one place. Moreover, the pendulum-slide cell oil pump 2 can be a two-stage design and therefore can comprise two pressure chambers in a manner known per se. A design as a fully variable pendulum-slide cell oil pump 2 is also conceivable.
Usually, the pump arrangement 1 according to the invention is driven by means of a drive that is mechanically coupled to the shaft 4 in the region of the pendulum-slide cell oil pump 2 so that the inner rotor 6 as well as the rotor 14 always have the same rotational speed. If individual controlling of the vacuum pump is desired, for example for a brake system of a motor vehicle, a coupling device 17 can be provided in the housing 5, which coupling permits separating the pendulum-slide cell oil pump 2 and the vacuum pump 3.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102014204946.6 | Mar 2014 | DE | national |
