# US 2014/0150743 A1 · Cam element for a valve drive train device

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- Number: US 2014/0150743 A1
- Document ID: US20140150743A1
- Status: Published application
- Kind: A1
- Application number: 14/175,682
- Filed: 2014-02-07
- Published: 2014-06-05
- Earliest claimed: 2012-07-17
- Assignees: Daimler AG
- Applicants: Daimler AG
- Inventors: Michael KUJAS; Thomas STOLK; Alexander VON GAISBERG-HELFENBERG
- Web page: https://patentgrep.com/patent/US20140150743A1

## CPC

- F01L 1/34: characterised by the provision of means for changing the timing of the valves without changing the duration of opening {and without affecting the magnitude of the valve lift}
- F01L 1/08: Shape of cams
- F01L 1/18: Rocking arms or levers
- F01L 13/0036: {the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction}
- F01L 2013/0052: {with cams provided on an axially slidable sleeve}
- Y10T 29/49293: Camshaft making
- F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

In a cam element for a valve drive train device of an internal combustion engine having at least one cam comprising at least two partial cams which are arranged next to one another and have a shared base circle phase in at least one angular camshaft range for valve lift switching by displacing their axial position with respect to a cam follower from one of the partial cams to another of the partial cams, the partial cams are angularly displaced in an axially overlapping arrangement. Also, between adjacent partial cams, a circular undercut is formed which has a center that is slightly offset from the rotational axis of the cam element so as to facilitate a switch over of valve actuation from one to another of the adjacent partial cams.

## Claims

### Claim 1

A cam element (17) for a valve drive train device of an internal combustion engine having at least one cam (10) that comprises at least two partial cams (11, 12) which are situated next to one another and have a shared base circle phase in at least one camshaft angular range (13) provided for valve lift switching by displacing their axial position with respect to a cam follower from one of the partial cams (11, 12) to another of the partial cams (11, 12), the partial cams (11, 12) being disposed on the cam element (17) in an angularly-displaced, axially overlapping arrangement.

### Claim 2 (depends on 1)

The cam element according to claim 1, wherein an undercut (14) is formed between adjacent two partial cams (11, 12).

### Claim 3 (depends on 2)

The cam element according to claim 2, wherein the undercut (14) has a manufacturing axis (15) which is offset relative to a rotational axis (16) of the cam element (17).

### Claim 4 (depends on 2)

The cam element according to claim 2, wherein the undercut (14) has areas with the shape of a truncated cone.

### Claim 5 (depends on 2)

The cam element according to claim 2, wherein the undercut (14) merges into the partial cams (11, 12) at a flat angle, at least in the base circle phase.

### Claim 6 (depends on 1)

A valve drive train device with a cam element (17) according to claim 1, and a valve lift switching unit which is provided for displacing the cam element (17) along its rotational axis (16) for changing the valve lift provided by the cam element.

### Claim 7

A method for manufacturing a cam element (17) for a valve drive train device of an internal combustion engine, the cam element having at least one cam (10) that has at least two partial cams (11, 12) which are situated next to one another and have a shared base circle phase in at least one camshaft angular range (13) provided for valve lift switching by displacing their axial position with respect to a cam follower from one of the partial cams (11, 12) to another of the partial cams (11, 12), said method comprising the step of forming a circular undercut (14) between the two partial cams (11, 12), which undercut has a center that is slightly offset from the axis of rotation of the camshaft.

### Claim 8 (depends on 7)

The method according to claim 7, wherein, after completion of the undercut (14), the partial cams (11, 12) are individually machined to the desired shape.