Camshaft adjusting device

Abstract

The disclosure relates to a camshaft adjusting device with a dry belt, a central valve arranged within a camshaft adjuster, and an actuator acting on the central valve. An oil-tight wet space is formed by the camshaft adjuster and the actuator or a component supporting the actuator, and oil present in the wet space can be evacuated by means of an oil path. A portion of this oil path extends axially through the output element of the camshaft adjuster. This oil path can pass the end-side contact face between the output element and camshaft, opening out into an axial bore of the camshaft which is distanced radially from the axis of rotation of the camshaft adjusting device. The axial bore runs beneath an oil feed connection formed on the outer surface of the camshaft for feeding oil to the central valve.

Claims

1. A camshaft adjusting device configured for a timing drive with a dry belt, the camshaft adjusting device comprising: a camshaft adjuster connected to a camshaft and configured to rotate about a rotational axis, a central valve arranged within the camshaft adjuster, the central valve configured to control a flow of oil to the camshaft adjuster, and an actuator acting on the central valve, and an oil-tight wet space formed by the camshaft adjuster and one of either the actuator or a component supporting the actuator, and an oil path configured to evacuate oil from the wet space, a portion of the oil path extending axially through a rotor of the camshaft adjuster, and the oil path configured to: i) extend past a contact interface between the rotor and the camshaft, and ii) fluidly connect to an axial bore arranged within the camshaft, and the axial bore: distanced radially from the rotational axis of the camshaft adjusting device, and configured radially inwardly of an oil feed connection formed on an outer surface of the camshaft, the oil feed connection configured to provide oil to the central valve, wherein the oil feed connection is configured as a circumferential groove on the outer surface of the camshaft.

2. The camshaft adjusting device according to claim 1, wherein the oil feed connection is configured as a circumferential groove on the outer surface of the camshaft, the circumferential groove fluidly connected via at least one radial bore, to a concentric bore of the camshaft, and the concentric bore configured to feed oil into the central valve, wherein the oil feed connection is configured as a circumferential groove on the outer surface of the camshaft.

3. The camshaft adjusting device according to claim 1, further comprising a roller bearing configured to support the camshaft, the roller bearing arranged between the oil feed connection and the camshaft adjuster in the axial direction.

4. The camshaft adjusting device according to claim 3, wherein the oil path does not flow through rolling elements of the roller bearing.

5. The camshaft adjusting device according to claim 3, wherein a seal is arranged axially between the oil feed connection and the roller bearing.

6. The camshaft adjusting device according to claim 1, wherein the oil path exits into a cylinder head of an internal combustion engine.

7. A camshaft adjusting device configured for a timing drive with a dry belt, the camshaft adjusting device comprising: a camshaft adjuster connected to a camshaft and configured to rotate about a rotational axis, an actuator configured to actuate the camshaft adjuster, an oil-tight wet space formed by the camshaft adjuster and one of either the actuator or a component supporting the actuator, and an oil path configured to evacuate oil from the wet space, the oil path having: a first portion extending axially within the camshaft adjuster from the wet space, and a second portion including an axially extending first bore within the camshaft, the axially extending first bore arranged radially inwardly of an oil feed connection of the camshaft, the oil feed connection configured to provide oil to the camshaft adjuster, wherein the oil feed connection is configured as a circumferential groove on the outer surface of the camshaft.

8. The camshaft adjusting device of claim 7, further comprising a roller bearing configured to support the camshaft, the roller bearing arranged between the oil feed connection and the camshaft adjuster in an axial direction.

9. The camshaft adjusting device of claim 8, further comprising a seal arranged between the oil feed connection and the roller bearing in the axial direction.

10. The camshaft adjusting device of claim 7, wherein the axially extending first bore is parallel to the rotational axis.

11. The camshaft adjusting device of claim 7, wherein the second portion has an exit end, the exit end configured to exit oil into a cylinder head of an internal combustion engine.

12. The camshaft adjusting device of claim 11, wherein the oil feed connection is arranged axially between the exit end and the camshaft adjuster.

13. The camshaft adjusting device of claim 11, wherein the oil feed connection is arranged axially between the exit end and a roller bearing, the roller bearing arranged to support the camshaft.

14. The camshaft adjusting device of claim 7, wherein a sum of a first axial length of the first portion and a second axial length of the second portion is greater than an axial length of the camshaft adjuster.

15. The camshaft adjusting device of claim 7, wherein the camshaft further comprises a second bore arranged radially inwardly of the axially extending first bore, the second bore fluidly connected to the oil feed connection and configured to provide oil to the camshaft adjuster.

16. The camshaft adjusting device of claim 15, further comprising a central valve, the central valve configured to: i) receive oil from the second bore; and, ii) control a flow of oil to the camshaft adjuster.

17. A camshaft adjusting device configured for a timing drive with a dry belt, the camshaft adjusting device comprising: a camshaft adjuster configured to rotate about a rotational axis, an actuator configured to actuate the camshaft adjuster, an oil-tight wet space formed by the camshaft adjuster and one of either the actuator or a component supporting the actuator, a camshaft attached to the camshaft adjuster at a first axial position on the camshaft, the camshaft having: an oil feed connection formed on an outer surface of the camshaft at a second axial position on the camshaft, a first axially extending bore configured to receive oil from the oil feed connection, and a second axially extending bore configured to exit oil from the wet space, and a roller bearing arranged to support the camshaft at a third axial position on the camshaft, the third axial position located between the first axial position and the second axial position.

18. The camshaft adjusting device of claim 17, wherein the second axially extending bore extends completely through the second axial position and the third axial position.

19. The camshaft adjusting device of claim 18, further comprising a third axially extending bore arranged within the camshaft adjuster, the third axially extending bore arranged axially between the oil-tight wet space and the second axially extending bore, and the second and third axially extending bores configured to evacuate oil from the oil-tight wet space to a cylinder head of an internal combustion engine.

20. The camshaft adjusting device of claim 19, further comprising a seal arranged between the roller bearing and the oil feed connection.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) An exemplary embodiment of the disclosure is shown in the FIGURE, wherein:

(2) FIG. 1 shows a section through the camshaft adjusting device according to the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(3) FIG. 1 shows a section through the camshaft adjusting device 1 according to the disclosure.

(4) The components of the camshaft adjusting device 1 according to the disclosure include the camshaft adjuster 2, the camshaft 3, the central valve 4, and the actuator 5 which is designed as a central magnet and controls the central valve 4, which in turn controls the camshaft adjuster 2. All of the aforementioned components are supported directly or indirectly by the cylinder head 20. For example, the actuator 5 is supported by a component 6 which is connected to the cylinder head 20. A wet space 7 is formed between the actuator 5, the component 6, and the camshaft adjuster 2, which wet space is sealed with a seal 21 from the dry belt space 22 in a fluid-tight manner.

(5) The camshaft adjuster 2 having the output element 9 is only shown schematically. A detailed illustration of the actuator 5 has been omitted, since it is known from the prior art.

(6) The wet space 7 collects the oil emerging from the end side of the central valve 4, where it can be returned to the hydraulic working chamber, for example, and/or can be discharged to a tank T according to the arrow.

(7) The oil supplied from a pressure medium source P first enters the camshaft adjusting device 1 via an oil feed connection 14 of the camshaft 3. By means of a circumferential groove 15 formed by the camshaft 3 and arranged on the outer surface 13 of the camshaft 3, the oil can be distributed around the circumference of the camshaft 3 and reach the radial bores 16 of the camshaft 3. Via these radial bores 16, the oil passes in the direction of the axis of rotation 12 into a bore 17 concentric with the camshaft 3, into which the central valve 4 partially projects. The supplied oil meets the central valve 4 on the end side in the bore 17 and, depending on the operating state, is distributed thereby to the hydraulic working chambers of the camshaft adjuster 2. The oil to be removed from the hydraulic working chambers emerges from the actuator-side end of the central valve 4 and into the wet space 7, where it can be collected.

(8) An oil path 8 is provided for evacuating the wet space 7 which extends through the entire axial length of the camshaft adjuster 2 and meets the contact face 10 between the camshaft adjuster 2 and the camshaft 3. There the oil path 8 opens into an axial bore 11 of the camshaft 3. This runs or extends beneath a camshaft-side seal 23 of the camshaft adjuster 2, which seals the dry belt space 22 from a roller bearing 18 arranged adjacent to the seal 23. The roller bearing 18 supports the camshaft 3 in the cylinder head 20. In the further course of the axial bore 11, it first runs or extends beneath or radially inwardly of the roller bearing 18 itself and then the oil feed connection 14, which is designed as a groove 15. A seal 19 is arranged between the roller bearing 18 and the oil feed connection 14 and seals the oil feed connection 14 to the roller bearing 18. The seal 19 can be present several times and flanks the groove 15 so that no oil flows from the oil feed connection 14 along the outer surface 13 of the camshaft 3 and wets adjacent components. The axial bore 11 is arranged parallel to and at a distance from the axis of rotation 12, but has a smaller radial distance from the axis of rotation 12 than the circumferential groove 15. Thus, the volume flows “from P” and “to T” intersect in the camshaft 3 in a skewed manner without communicating directly with each other. The oil to be discharged can thus be drained very directly into the cylinder head 20 without, for example, flowing through the roller bearing 18 or being deflected through further bores in the cylinder head 20.

LIST OF REFERENCE CHARACTERS

(9) 1 Camshaft adjusting device 2 Camshaft adjuster 3 Camshaft 4 Central valve 5 Actuator 6 Component 7 Wet space 8 Oil path 9 Output element 10 Contact face 11 Axial bore 12 Axis of rotation 13 Outer surface 14 Oil feed connection 15 Circumferential groove 16 Radial bore 17 Concentric bore 18 Roller bearing 19 Seal 20 Cylinder head 21 Seal 22 Dry belt space 23 Seal P Pressure medium source T Tank