HYBRID BEARING BLOCK FOR A CAMSHAFT

Abstract

A bearing apparatus for mounting a camshaft in a cylinder head of an internal combustion engine may include a bearing element that surrounds a bearing ring in which the camshaft is rotatably mounted or mountable. The bearing element may be made of a first material whose expansion coefficient is greater than an expansion coefficient of a second material of which the bearing ring is made. An outer surface of the bearing ring may include a contour that engages in a form-fitting manner with a mating contour formed on an inner surface of the bearing element that surrounds the bearing ring. The contouring formed by the contour and the mating contour may form retaining structures that brace against one another in instances of thermal expansion.

Claims

1.-8. (canceled)

9. A bearing apparatus for mounting a camshaft, the bearing apparatus comprising: a bearing block including two screw bores by way of which the bearing block is securable to a base of a camshaft module, the bearing block further including an oil duct; and a bearing ring in which a camshaft is rotatably mounted or mountable, the bearing ring being injected or cast into the bearing block, wherein the bearing ring includes an outer surface having a contour that is adjacent to the bearing block and retains the bearing ring within the bearing block, wherein the bearing ring receives oil from the oil duct.

10. The bearing apparatus of claim 9 wherein the contour of the outer surface of the bearing ring comprises two undercuts that are formed by a raised portion having an M-like profile.

11. The bearing apparatus of claim 9 wherein the contour of the outer surface of the bearing ring is configured as a dovetail recess.

12. The bearing apparatus of claim 9 wherein an expansion coefficient of the bearing block is greater than an expansion coefficient of the bearing ring.

13. The bearing apparatus of claim 9 wherein the outer surface of the bearing ring comprises a retaining structure to improve a connection between the bearing ring and the bearing block.

14. The bearing apparatus of claim 13 wherein the retaining structure comprises an axially-extending recess.

15. The bearing apparatus of claim 13 wherein the retaining structure comprises a circumferentially-extending groove.

16. The bearing apparatus of claim 13 wherein the retaining structure comprises anchors that extend into the bearing block and are surrounded by the bearing block in form-fitting fashion.

17. The bearing apparatus of claim 13 wherein the retaining structure comprises an anchor that extends into and is surrounded at least partially by the bearing block, wherein the anchor comprises an oil duct.

18. The bearing apparatus of claim 9 wherein the bearing ring comprises two lateral eyelets that have bores that overlap with the two screw bores of the bearing block.

19. The bearing apparatus of claim 9 wherein the bearing ring is a first bearing ring, the bearing apparatus further comprising a second bearing ring, wherein the first and second bearing ring are connected by a bridge element that is secured in the bearing block.

20. A bearing apparatus for mounting a camshaft in a cylinder head of an internal combustion engine, the bearing apparatus comprising: a bearing element that is comprised of a first material that has a first expansion coefficient, a bearing ring in which a camshaft is rotatably mounted or mountable, the bearing ring comprised of a second material having a second expansion coefficient, wherein the first expansion coefficient is greater than the second expansion coefficient, wherein the bearing ring is surrounded by the bearing element; and wherein the bearing ring includes an outer surface with a contour that engages in a form-fitting manner a mating contour of an inner surface of the bearing element that surrounds the bearing ring, wherein contour and the mating contour form a retaining structures that brace against one another in an event of thermal expansion.

21. The bearing apparatus of claim 20 wherein the bearing ring is cast into the bearing element, with the bearing element being configured as a single bearing block.

22. The bearing apparatus of claim 20 wherein the contour is recessed into the outer surface of the bearing ring and surrounds the bearing ring in axisymmetric fashion, wherein the mating contour engages in the recessed contour.

23. The bearing apparatus of claim 20 wherein the contour is raised above the outer surface of the bearing ring and forms an anchor that engages in the bearing element.

24. The bearing apparatus of claim 23 wherein the bearing ring is a first bearing ring, the bearing apparatus further comprising a second bearing ring, wherein the first and second bearing rings are connected by a common anchor configured as a bridge element and form a dual bearing plate that is cast into the bearing element.

25. The bearing apparatus of claim 20 wherein the second expansion coefficient is approximately equal to or greater than an expansion coefficient of material of which the camshaft is comprised.

26. A system comprising: a bearing element comprised of a first material having a first expansion coefficient; a bearing ring comprised of a second material having a second expansion coefficient, wherein an outer surface of the bearing ring includes a contour that engages in a form-fitting manner with a mating contour of an inner surface of the bearing element such that the bearing element holds the bearing ring in a form-fitting manner, with the contour and the mating contour forming retaining structures that brace against one another in an event of thermal expansion; and a camshaft that is rotatably mounted in the bearing ring and is made of a third material having a third expansion coefficient, wherein the first expansion coefficient is greater than the second and third expansion coefficients.

27. The system of claim 26 wherein the second and third expansion coefficients differ by less than 5%.

28. The system of claim 26 wherein the bearing ring and the camshaft are comprised of a steel or a gray cast iron, wherein the bearing element is comprised of aluminum or a magnesium alloy.

Description

PREFERRED EXEMPLARY EMBODIMENTS OF THE INVENTION

[0018] One embodiment of the module according to the invention is explained in greater detail below with reference to the figures, in which:

[0019] FIG. 1 shows a bearing ring with undercuts, injected into a bearing block,

[0020] FIG. 2 shows the transfer of forces from the bearing block to the bearing ring,

[0021] FIG. 3 shows a bearing block with a contoured bearing ring,

[0022] FIG. 4 shows a bearing block with an injected bearing ring comprising lateral eyelets,

[0023] FIG. 5 shows a bearing block with an injected bearing ring comprising an anchor,

[0024] FIG. 6 shows a dual bearing plate injected into the bearing block.

[0025] FIG. 1 a shows a separate bearing block 1 which, together with a bearing ring 2 injected or cast therein, forms a mount for a camshaft (not shown) in a cylinder head of an internal combustion engine. The bearing block 1 is cast from aluminum and comprises two screw bores 3 by means of which it is secured to the base of a camshaft module. Also visible is an oil duct 4 in the form of a bore which leads from below, through the bearing block 1 and the bearing ring 2, into the sliding bearing (see also FIG. 1b). FIG. 1b shows a section through the bearing block 1 of FIG. 1a. It shows the contour 5 introduced into the outer jacket of the bearing ring 2 with two undercuts 6 that are formed by a raised portion having an M-like profile. The material of the bearing block 1 engages behind the undercuts.

[0026] FIG. 2a shows a similar combination of a bearing block 1 and a cast-in bearing ring 2, in a section view. In this case, the contouring is a dovetail recess 6 which is incised into the outer jacket of the bearing ring. FIG. 2b shows the dovetail profile of the recess 6 in detail. Also, the arrows show the force flow of the cooling bearing block 1 on the bearing ring 2. As can be seen, this force flow is radially inward. On heating, the aluminum bearing block 1 expands more than the steel bearing ring 2, resulting in tension in the axial direction.

[0027] FIGS. 3a and 3b show a variant embodiment in which there are provided retaining structures in the form of axially extending recesses 7 and a circumferentially extending groove 8. In that context, the surface areas are increased using the alfin process, so as to result in better adhesion.

[0028] FIG. 4 shows an embodiment in the cutaway state, in which the retaining structure of the bearing ring 2 forms multiple anchors that reach into the material of the bearing block 1 and are surrounded thereby in form-fitting fashion. In that context, two molded-on eyes 9, which are molded-on on either side of the bearing ring 2 in the screwing plane and are dimensioned such that the bores of the eyelets 9 are in line with the lateral screw bores 3, serve as anchors. If the bearing block is screwed onto the camshaft module by means of screws inserted into the screw bores 3, the screws also pass through the eyelets 9. As is also the case of the embodiment shown in FIG. 3, a circumferentially extending groove 8 is provided in the bearing ring 2 and provides additional stability. It can be seen that this embodiment also has an oil duct 4 that leads into the bearing ring 2.

[0029] In the exemplary embodiment of FIG. 5, the oil duct 4 is introduced into the anchor 10 that is molded onto the bearing ring 2 and projects vertically downward. In that context, another axial protrusion 11, which is undercut by the material of the bearing block, can be provided at the upper end of the bearing ring 2 as shown in FIG. 5.

[0030] In the exemplary embodiment of FIG. 6, two bearing rings 2 are connected via a common anchor in the form of a bridge element 12, and thus form a dual bearing plate 13. The dual bearing plate formed in this manner is again cast into the bearing element 1.

LIST OF REFERENCE SIGNS

[0031] 1 Bearing block

[0032] 2 Bearing ring

[0033] 3 Screw bore

[0034] 4 Oil duct

[0035] 5 Contour

[0036] 6 Undercuts

[0037] 7 Recesses

[0038] 8 Groove

[0039] 9 Eyelet

[0040] 10 Anchor

[0041] 11 Protrusion

[0042] 12 Bridge element

[0043] 13 Dual bearing plate