Patent Application
20130134007
The invention relates to a dual clutch transmission of a motor vehicle according to the preamble of patent claim 1, known from EP 1954965 B1.
From EP 1 954 965 B1, in which the applicant is named as the assignee, a double clutch transmission having a so-called oil chamber partition, that is to say, having a first oil or clutch chamber that accommodates a double clutch and a second oil or transmission chamber that accommodates a double clutch gear set transmission, called in short a gear set. The oil chamber partition in a double clutch transmission enables the use of different oils for the wet running double clutch and lubrication of the gear set. The clutch chamber and the transmission chamber are separated by a partition wall. The double clutch has two coaxially positioned drives, a center shaft and a hollow shaft, which extend from the clutch chamber through the partition wall into the transmission chamber. Hereby, the hollow shaft is sealed in its circumferential area with respect to a bore in the partition wall, while the central shaft is sealed with respect to to the hollow shaft.
Based on the state of the art, the object of the present invention is to secure the oil supply in both oil chambers, meaning for the double clutch as well as for the transmission or rather the gear set.
The object of the invention is achieved by the features of patent claim 1. Advantageous embodiments are evident from the dependent claims.
In accordance with the invention, the above mentioned state of the art has an oil pump which is positioned in the transmission chamber and which can be driven by a drive shaft which extends through the partition wall. That has the advantage that the transmission chamber or the gear set which is positioned in the transmission chamber, respectively, is supplied with oil by a separate oil pump which can be driven by the internal combustion engine of the motor vehicle. The separate oil pump, also called a gear set pump, conveys preferably lubrication oil for injection lubrication of the gear wheels of a gear set.
In a preferred embodiment, the oil pump can be driven via the drive shaft at the rotational speed of the combustion engine, meaning the input rotational speed for the transmission. This ensures that in all locations of the operation the required and conveyed amounts and pressures are provided for the functioning of the injection lubrication. It is also advantageous that the gear set pump, due to its mechanical drive, has a relatively high efficiency, especially compared to an electrically driven oil pump.
In an additional advantageous embodiment, the drive shaft is driven via a spur gear stage, which is positioned in the clutch chamber, meaning at the output side of the combustion engine. Hereby, the spur gear is driven by the combustion engine and in turn drives a spur gear which is positioned on the drive shaft of the gear set pump.
In an additional advantageous embodiment, the drive shaft which is extends through a bore in the partition wall, is sealed relative to the partition wall by suitable sealing members, such as for instance radial shaft seal rings. This ensures that separation of the oil chambers is maintained—despite the drive shaft for the gear set pump.
In an additional preferred embodiment, the oil pump comprises of a pump shaft which mates with the drive shaft via a connector. Thus, making easy installation of the oil pump in the gear set chamber possible, creating at the same time a rotationally fixed connection with the drive shaft. The connector is preferably designed as spline meshing.
In another advantageous embodiment, the oil pump is designed as a gear wheel pump. Thus, relatively large pressures can be provided for the injection lubrication.
In another advantageous embodiment, an additional pump is provided, meaning a hydraulic pump, which is also driven by the internal combustion engine. Here—also in the clutch chamber—an additional spur gear can be provided, which is positioned on a pump drive shaft for the hydraulic pump. Therefore, both pump drives or gear drive wheels, respectively, can be positioned in the clutch chamber and can be driven by the engine.
An embodiment of the invention is illustrated in the drawing and will be described in greater detail, wherein further characteristics and/or advantages can arise from the description and/or the drawing. These show:
The partition wall 9 is penetrated by the drive shaft 7, wherein the partition wall 9 has a boring 9a, through which the drive shaft 7 extends and which is sealed by sealing members 10, preferably radial shaft gasket rings. Within the gear set chamber 8, an oil pump 11, also called a gear set pump 11, is positioned at and fixed to the partition wall 9. The gear set pump 11 is designed as gear wheel pump and comprises a housing 11a, a pump shaft 11b, an inner rotor 11c, as well as an outer rotor 11d. The pump shaft 11b is connected in a rotationally fixed manner, via a connector 12, with the drive shaft 7 and is herewith driven via the first drive spur gear 5 by means of the combustion engine. The oil pump 11 delivers preferably lubrication oil for injection lubrication of the gear wheels of the double clutch transmission gear set.
Independent of the gear set pump 11, a not shown hydraulic pump is provided which via the drive spur gear 6 (see
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2011 087 164.0 | Nov 2011 | DE | national |
