The present application is related and has right of priority to German Patent Application No. 102020215912.2 filed in the German Patent Office on Dec. 15, 2020, which is incorporated by reference in its entirety for all purposes.
The present invention generally concerns an arrangement with a component for a transmission of a vehicle. The invention furthermore generally concerns a transmission with the arrangement.
In automotive technology, automatic transmissions are known in which several actuatable shift elements are provided in order to achieve translation ratios, via which elements a torque is transmitted from an input shaft to the output. The shift elements are actuated hydraulically. For this, inter alia, cylindrical components are required which are rotationally fixedly and axially movably connected to an input shaft of the automatic transmission. The components have passage bores for hydraulic pressure balancing.
It has been found that in the region of the passage bores, considerable mechanical loads occur on the components so that premature component failure may occur.
Example aspects of the present invention provide an arrangement of the type described initially, and a transmission with the arrangement, in which premature component failure is prevented.
An arrangement is thus proposed with at least one component for a transmission of a vehicle, wherein the component has an annular cylindrical interior and is rotationally fixedly and axially movably connected to an input shaft. The component has at least one passage bore for hydraulic pressure balancing or oil conduction. In order to prevent premature component failure, the annular cylindrical interior of the component has at least one interior contour assigned to the passage bore as an area reducing stress concentration.
The modified design of the interior contour of the component creates a homogenous distribution of the mechanical forces occurring, so as to improve component strength. The proposed interior contour conducts the mechanical stresses past the passage bore and thus reduces the mechanical stresses and loads occurring. Because the strain tensors occurring run more homogenously along the passage bore, the component strength is significantly higher.
It is particularly advantageous if the interior contour of the component reducing the stress concentration is provided or runs at least between a shaft or outlet region of the passage bores and an internal diameter of the annular cylindrical interior of the component. The greatest mechanical loads occur in this region, so it is particularly advantageous to change the stress development in this area accordingly so that no stress peaks can occur in this region. This considerably extends the component service life.
In principle, it is possible to achieve the interior contour reducing the stress concentration in various structural ways. For example, the interior contour reducing the stress concentration may form a constant polynomial line as a curve, viewed in longitudinal section. Here, the interior contour is achieved by several polynomial function curves provided one after the other, wherein the respective transitions between the polynomial function curves are constant, i.e., formed in a predefined radius, and have no non-constant jumps in the curve.
Another way of designing the interior contour reducing the stress concentration may for example be to implement a constant radius as a curve, viewed in longitudinal section. Irrespective of the actually selected course of the interior contour, in any case a particular homogenous mechanical stress distribution is achieved with improved component strength.
The annular cylindrical interior is particularly suitable if the component is arranged coaxially to the input shaft. In this design, the internal diameter of the annular cylindrical interior corresponds to an external diameter of a sleeve region for attaching the component to the input shaft. Accordingly, the interior is arranged radially on the outside of the component, while the sleeve region of the component is arranged on the radial inside and receives the input shaft. In this way, a particularly compact arrangement is achieved since a radially nested structure is possible.
A further example aspect of the invention claims a transmission with the arrangement as described above, so that the advantages already described and further advantages are achieved. As a transmission, preferably an eight-speed automatic transmission may be provided. Particularly advantageously, the component is designed as an inner plate carrier of a shift element configured as a friction clutch.
Example aspects of the invention are described in more detail below with reference to the drawings. The drawings shows:
Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.
The component 1 of the arrangement according to example aspects of the invention is rotationally fixedly and axially movably connected to an input shaft 2. For actuation of the friction clutch 8, the component 1 has an annular cylindrical interior 3 in which a hydraulically actuated piston is movable. Several passage bores 4 are provided on the component 1 for hydraulic pressure balancing, as evident for example from
In order to achieve a significantly greater component strength, it is provided that the annular cylindrical interior 3 of the component 1 has at least one interior contour 5A, 5B assigned to the passage bore 4 as an area reducing stress concentration.
Irrespective of the example design variants, with the arrangement according to example aspects of the invention, it is provided that the component 1 is arranged coaxially to the input shaft 2, and an internal diameter 7 of the annular cylindrical interior 3 forms an external diameter of the sleeve region 9 for attaching the component 1 to the input shaft 2. Accordingly, the input shaft 2 is arranged inside the sleeve region 9, while the cylindrical interior 3 of the component 1 extends radially on the outside around the sleeve region 9. The interior contour 5A, 5B of the component 1 reducing the stress concentration runs at least between a shaft or outlet region 11 of the passage bore 4 and the internal diameter 7 of the annular cylindrical interior 3.
Modifications and variations can be made to the embodiments illustrated or described herein without departing from the scope and spirit of the invention as set forth in the appended claims. In the claims, reference characters corresponding to elements recited in the detailed description and the drawings may be recited. Such reference characters are enclosed within parentheses and are provided as an aid for reference to example embodiments described in the detailed description and the drawings. Such reference characters are provided for convenience only and have no effect on the scope of the claims. In particular, such reference characters are not intended to limit the claims to the particular example embodiments described in the detailed description and the drawings.
Number | Date | Country | Kind |
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10 2020 215 912.2 | Dec 2020 | DE | national |