# US 9,038,586 B2 · Rocker assembly having improved durability

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- Number: US 9,038,586 B2
- Document ID: US9038586B2
- Status: Granted
- Kind: B2
- Application number: 13/868,061
- Filed: 2013-04-22
- Published: 2013-11-28
- Granted: 2015-05-26
- Earliest claimed: 2010-03-19
- Assignees: Eaton Corporation
- Applicants: Eaton Corporation
- Inventors: Otto Jerome Schultheis; Tony Eric Gordon; Mark Joseph Birler; Philip Michael Kline
- Web page: https://patentgrep.com/patent/US9038586B2

## 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 1/185: {Overhead end-pivot rocking arms}
- F01L 13/0005: {Deactivating valves}
- 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 2001/186: {Split rocking arms, e.g. rocker arms having two articulated parts and means for varying the relative position of these parts or for selectively connecting the parts to move in unison}
- Y10T 74/2107: Follower
- F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A durable system is disclosed for controlling variable valve actuation of an engine valve corresponding to a cylinder of an automobile engine. The system is designed to have a durability that exceeds the expected life of a conventional automobile engine. The system includes first crowned cam having a first lift profile, a second crowned cam having a second lift profile, and a rocker arm assembly. The rocker assembly includes a first arm having an end connected to said engine valve, having a high impact roller following the first crowned cam operating the engine valves according to a first lift profile. The rocker arm assembly also includes a second arm having slider pads riding on the second crowned cam to operate said engine valve according to a second lift profile. The slider pads have a sliding surface covered with an impact-resistant multilayer coating with its outermost coating being a wear-resistant coating. A latch having adjustable latch lash secures the second arm relative to the first arm when in a latched position causing the valve to operate according to a second lift profile when the latch is in a latched position, and the valve is operated according to a first lift profile when the latch is not in a latched position.

## Claims

### Claim 1

A system for controlling variable valve actuation of an engine valve corresponding to a cylinder of an automobile engine having a durability exceeding the expected life of a conventional automobile engine, the system comprising:
a first crowned cam having a first lift profile;
a second crowned cam having a second lift profile; and
a rocker arm assembly comprising:
a first arm having an end connected to said engine valve, the first arm riding on the first crowned cam and having a high impact roller following the first crowned cam adapted to operate said engine valve according to the first lift profile;
a second arm having at least one slider pad adapted to ride on the second crowned cam to operate said engine valve according to the second lift profile; and
a latch adapted to have an adjustable latch lash and secure the second arm relative to the first arm when in a latched position;
wherein the valve is operated according to the second lift profile when the latch is in a latched position and
the valve is operated according to the first lift profile when the latch is not in a latched position.

### Claim 2 (depends on 1)

The system of claim 1 wherein the high impact roller employs a hardened axle.

### Claim 3 (depends on 1)

The system of claim 1 wherein the at least one slider pad comprises: two substantially parallel curved slider pads manufactured to have less than a predetermined included angle.

### Claim 4 (depends on 3)

The system of claim 3 wherein: the substantially parallel curved slider pads have less than a +/−0.8 degree angle deviation.

### Claim 5 (depends on 3)

The system of claim 3 wherein: the substantially parallel curved slider pads have less than a +/−0.4 degree angle deviation.

### Claim 6 (depends on 1)

The system of claim 1 wherein: the at least one slider pad is coated with a multilayer wear-resistant coating including a layer exhibiting increased ductility as compared with that of the slider pad to absorb impact.

### Claim 7 (depends on 6)

The system of claim 6 wherein: the at least one slider pad comprises a polished curved surface beneath the wear-resistant coating.

### Claim 8 (depends on 7)

The system of claim 7 wherein: the at least one slider pad comprises an adhesion layer between the polished surface and the layer exhibiting increased ductility.

### Claim 9 (depends on 1)

The system of claim 1 wherein the crowned cam is polished.

### Claim 10 (depends on 1)

The system of claim 1 wherein the crowned cam comprises: a hardened cam having a raised center crown which reduces edge loading of the slider pads.

### Claim 11 (depends on 1)

The system of claim 1 wherein crowned cam comprises: a crowned cam made of steel having a polished engagement surface.

### Claim 12 (depends on 1)

The system of claim 1, wherein the adjustable latch lash is adjustable within limits such that the adjustable latch lash and a cam lash comprise a total mechanical lash.

### Claim 13 (depends on 1)

The system of claim 1, wherein the adjustable latch lash comprises a spacing between a latch pad surface of the latch and an arm engaging surface of the second arm.

### Claim 14

A system for controlling variable valve actuation of an engine valve corresponding to a cylinder of an automobile engine having a durability exceeding the expected life of a conventional automobile engine, the system comprising:
a first crowned cam having a first lift profile;
a second crowned cam having a second lift profile; and
a rocker arm assembly comprising:
a first arm having an end connected to said engine valve, the first arm riding on the first crowned cam and having a high impact roller following the first crowned cam adapted to operate said engine valve according to the first lift profile;
a second arm having at least one slider pad adapted to ride on the second crowned cam to operate said engine valve according to the second lift profile; and and
a latch adapted to have an adjustable latch lash and secure the second arm relative to the first arm when in a latched position,
wherein the at least one slider pat has a sliding surface covered with an impact-resistant multilayer coating with its outermost coating being a wear-resistant coating, and
wherein the valve is operated according to the second lift profile when the latch is in a latched position and the valve is operated according to the first lift profile when the latch is not in a latched position.

### Claim 15 (depends on 14)

The system of claim 14, wherein the impact-resistant multilayer coating comprises: a ductile layer between the wear-resistant coating and the at least one slider pad to absorb impacts and prevent the wear-resistant coating from cracking.

### Claim 16 (depends on 14)

The system of claim 14, wherein the sliding surface is polished before the impact-resistant multi-layer coating is applied.

### Claim 17 (depends on 14)

The system of claim 14, wherein the impact-resistant multilayer coating comprises: an adhesive layer between the ductile layer and the sliding surface.

### Claim 18 (depends on 14)

The system of claim 14, wherein the adjustable latch lash and an adjustable cam lash comprise a total mechanical lash that remains constant over a life of the engine valve for an engine using the system for controlling variable valve actuation of the cylinder.

### Claim 19 (depends on 14)

The system of claim 14, wherein the adjustable latch lash comprises a clearance or spacing between a latch pad surface of the latch and an arm engaging surface of the second arm.

### Claim 20 (depends on 14)

The system of claim 14, wherein the adjustable latch is a component of a dual feed hydraulic lash adjuster and further comprising remaining components of the dual feed hydraulic lash adjuster.