CAMSHAFT HAVING AT LEAST ONE AXIALLY FIXED SLIDING ELEMENT

Abstract

A camshaft for a multiple-cylinder internal combustion engine may include a sliding element comprising at least two cam elements, as well as a splined shaft that extends in an axial direction and on which the sliding element is received. The sliding element may comprise an internal spline system that interacts with an external spline system of the splined shaft such that the sliding element is seated fixedly on the splined shaft so as to rotate with the splined shaft. The sliding element may be received on the splined shaft such that the sliding element can, at least initially, be displaced axially. For axially-fixing the sliding element to the splined shaft, the sliding element may include a positively locking connection that is configured in the axial direction and is produced by way of at least one calked connection between the sliding element and the splined shaft. It should be understood that many camshafts include more than one sliding element.

Claims

1.-11. (canceled)

12. A camshaft for a multiple-cylinder internal combustion engine, the camshaft comprising: a sliding element comprising at least two cam elements for selective control of valves of the multiple-cylinder internal combustion engine, wherein the sliding element includes an internal spline system; and a splined shaft extending in an axial direction, wherein the sliding element is received on the splined shaft, wherein the internal spline system of the sliding element interacts with an external spline system of the splined shaft such that the sliding element is seated fixedly on the splined shaft so as to rotate with the splined shaft, wherein the sliding element is received on the splined shaft in an axially displaceable manner, wherein the sliding element is configured to be fixed in the axial direction to the splined shaft by way of a positively locking connection comprising a calked connection between the sliding element and the splined shaft.

13. The camshaft of claim 12 further comprising a plurality of sliding elements, with the sliding element being one of the plurality of sliding elements.

14. The camshaft of claim 12 wherein at least one of the splined shaft comprises an interruption of the external spline system at an axial position, wherein a part of the sliding element is calked in sections, or the sliding element comprises a receiving geometry into which a part of the splined shaft is calked in sections.

15. The camshaft of claim 12 wherein the sliding element comprises a support tube on which the at least two cam elements are received, wherein the calked connection exists between the support tube of the sliding element and the splined shaft.

16. The camshaft of claim 15 wherein the support tube comprises an end-side section with a reduced tube wall thickness, wherein the calked connection is configured in a region of the end-side section of the support tube.

17. The camshaft of claim 12 wherein the sliding element comprises axial end sides, the camshaft further comprising at least two calked connections between the sliding element and the splined shaft on each of the axial end sides of the sliding element, wherein the at least two calked connections are distributed about a circumference of the splined shaft.

18. The camshaft of claim 12 wherein the sliding element comprises axial end sides, the camshaft further comprising at least three calked connections between the sliding element and the splined shaft on each of the axial end sides of the sliding element, wherein the at least three calked connections are distributed about a circumference of the splined shaft.

19. The camshaft of claim 12 wherein the sliding element comprises axial end sides, the camshaft further comprising four calked connections between the sliding element and the splined shaft on each of the axial end sides of the sliding element, wherein the four calked connections are distributed about a circumference of the splined shaft.

20. The camshaft of claim 12 wherein the splined shaft comprises an interruption of the external spline system at an axial position, wherein the interruption comprises a circumferential groove in the splined shaft.

21. The camshaft of claim 12 wherein the sliding element includes a bearing section by way of which the sliding element can be received in a rotatably mountable manner on a bearing bracket.

22. A method for producing a camshaft for a multiple-cylinder internal combustion engine, the method comprising: providing a sliding element with at least two cam elements for selective control of valves of the multiple-cylinder internal combustion engine, wherein the sliding element includes an internal spline system; providing a splined shaft that extends in an axial direction and includes an external spline system; guiding the splined shaft through the sliding element so that the sliding element is seated fixedly on the splined shaft and rotates with the splined shaft due to interaction between the internal and external spline systems, wherein the sliding element is axially displaceable with respect to the splined shaft; and producing a calked connection between the sliding element and the splined shaft to fix the sliding element in the axial direction on the splined shaft.

23. The method of claim 22 wherein the sliding element that is provided includes a support tube comprising an end-side section with a reduced tube wall thickness, wherein the calked connection is produced in a region of the end-side section.

24. The method of claim 22 wherein the sliding element is provided in a bearing bracket of a camshaft module such that calking of the support tube on the splined shaft is performed in or on the camshaft module.

25. The method of claim 22 further comprising providing a calking tool for producing the calked connection between the sliding element and the splined shaft, wherein the calked connection is produced when the sliding element is positioned in a bearing bracket of a camshaft module.

Description

PREFERRED EXEMPLARY EMBODIMENT OF THE INVENTION

[0016] Further measures which improve the invention will be shown in greater detail in the following text together with the description of one preferred exemplary embodiment of the invention using the figures, in which:

[0017] FIG. 1 shows a view of a camshaft in a non-mounted arrangement of a sliding element on a splined shaft,

[0018] FIG. 2 shows the view of the camshaft according to FIG. 1, the sliding element being arranged on the splined shaft, and

[0019] FIG. 3 shows a view of a camshaft with a sliding element which is secured axially on the splined shaft via a calked connection of the support tube to said splined shaft.

[0020] FIG. 1 shows a section of a splined shaft 14 and, by way of example, a single sliding element 10, and the sliding element 10, as well as further sliding elements 10, can be pushed onto the splined shaft 14 in order to form a camshaft. For the transmission of torque between the sliding element 10 and the splined shaft 14, the sliding element 10 comprises an internal spline system 15 in a passage, and the splined shaft 14 comprises an external spline system 16. It is shown, furthermore, that two interruptions 18 are made in the splined shaft 14, which interruptions 18 are at an axial spacing from one another which corresponds to the axial spacing of end-side sections 20 of the sliding element 10. When the splined shaft 14 is introduced into the sliding element 10, the internal spline system 15 engages into the external spline system 16. In this way, the sliding element 10 is arranged fixedly on the splined shaft 14 so as to rotate with it and such that it can be displaced in the axial direction 13.

[0021] The sliding element 10 comprises a support tube 12, and cam elements 11.1 and 11.2 are received on the support tube 12. A bearing bracket 22 which can be a constituent part, for example, of a module cover for forming a camshaft module or a cylinder head is situated between the cam elements 11.1 and 11.2. Here, the sliding element 10 is mounted rotatably via the support tube 12 on a bearing section 21 in the bearing bracket 22.

[0022] On the existing end sides, as viewed in the axial direction 13, in particular outside the setting locations for receiving the cam elements 11.1 and 11.2, the support tube 12 comprises the end-side sections 20 with a reduced wall thickness. The reduced wall thickness results from the fact that the external diameter of the support tube 12 is reduced in the end-side sections 20. When the splined shaft 14 is introduced into the sliding element 10 in the arrow direction which is shown, the arrangement according to FIG. 2 is produced, as described in the following text.

[0023] FIG. 2 shows a camshaft 1 in a view in sections, the splined shaft 14 being guided through a sliding element 10, and the splined shaft 14 comprising two interruptions 18 in the form of circumferential grooves, and the interruptions 18 corresponding by way of the axial position along the axial direction 13 with the end-side sections 20. A calking tool 23 serves to calk the support tube 12 on the splined shaft 14, which calking tool 23 is shown with two punches which can be moved radially in the arrow direction onto the end-side section 20 for plastic deformation. When the calking tool 23 is activated, local calking of the end-side section 20 into the interruption 18 of the splined shaft 14 can be achieved, as shown in the following FIG. 3.

[0024] FIG. 3 shows a view in sections of the camshaft 1 with the splined shaft 14, on which the sliding element 10 is received. As viewed in the axial direction 13, the support tube 12 is delimited on both end sides by way of the end-side section 20, and material parts 19 of the end-side sections 20 have been calked in sections into the interruption 18 by way of plastic deformation, by the calking tool 23 having been activated, as shown in FIG. 2. A positively locking connection in the axial direction 13 is produced between the support tube 12 and the splined shaft 14 by way of the material part 19 being formed in sections into the interruption 18, as a result of which the sliding element 10 is fixed on the splined shaft 14 such that it cannot be displaced in the axial direction 13.

[0025] The sliding element 10 is received by way of example in a bearing bracket 22, and further sliding elements 10 can be received on the splined shaft 14 adjacently with respect to the fixed sliding element 10 which is shown, which further sliding elements 10 remain axially displaceable and can likewise be received in bearing brackets 22.

[0026] The implementation of the invention is not restricted to the preferred exemplary embodiment which is specified above. Rather, a number of variants are conceivable which use the solution which is shown, even in the case of embodiments of a fundamentally different type. All of the features and/or advantages which are apparent from the claims, the description or the drawings, including structural details or spatial arrangements, can be essential to the invention both per se and in a very wide variety of combinations.

LIST OF DESIGNATIONS

[0027] 1 Camshaft [0028] 10 Sliding element [0029] 11.1 Cam element [0030] 11.2 Cam element [0031] 12 Support tube [0032] 13 Axial direction [0033] 14 Splined shaft [0034] 15 Internal spline system [0035] 16 External spline system [0036] 17 Calked connection [0037] 18 Interruption [0038] 19 Material part in sections [0039] 20 End-side section [0040] 21 Bearing section [0041] 22 Bearing bracket [0042] 23 Calking tool