Split axial cam shifting system variable valve actuation functions

Patent metadata

Field	Value
Publication number	US-10544708-B2
Application number	US-201715722649-A
Country	US
Kind code	B2
Filing date	Oct 2, 2017
Priority date	Apr 2, 2015
Publication date	Jan 28, 2020
Grant date	Jan 28, 2020

Abstract

A valve train assembly configured to selectively open and close intake and exhaust valves associated with cylinders of an internal combustion engine comprises an intake rocker arm assembly, an intake cam assembly, a first axial shifting cam assembly and a second axial shifting cam assembly. The intake rocker arm assembly can have a plurality of intake rocker arms. The intake cam assembly can be associated with each of the cylinders and can have three distinct cam profiles including a first cam profile, a second cam profile and a third cam profile. The first axial shifting cam assembly can operate independently from the second axial shifting cam assembly to provide three distinct valve lift profiles on the first grouping of cylinders and three distinct valve lift profiles on the second grouping of cylinders.

First claim

What is claimed is:

1. A valve train assembly configured to selectively open and close intake and exhaust valves associated with cylinders of an internal combustion engine, the valve train comprising:
an intake rocker arm assembly having a plurality of intake rocker arms;
an intake cam assembly associated with each of the cylinders and having three distinct cam profiles including a first cam profile, a second cam profile and a third cam profile;
a first axial shifting cam assembly movable between a first, second and third axial position corresponding to alignment of the respective three distinct cam profiles with intake rocker arms associated with a first grouping of the cylinders, wherein the first axial shifting cam assembly includes three cam assemblies having a central cam assembly that operates as a master actuation system and two outer cam assemblies that operate as slave actuation systems; and
a second axial shifting cam assembly movable between a first, second and third axial position corresponding to alignment of the respective three distinct cam profiles with intake rocker arms associated with a second grouping of the cylinders, distinct from the first grouping of cylinders;
wherein the first axial shifting cam assembly operates independently from the second axial shifting cam assembly to provide three distinct valve lift profiles on the first grouping of cylinders and three distinct valve lift profiles on the second grouping of cylinders.

2. The valve train assembly of claim 1 wherein the intake cam assembly associated with the first grouping of cylinders comprises the first cam profile that provides a normal mode, the second cam profile that provides a cylinder deactivation mode, and the third cam profile that provides a first Miller cycle mode.

3. The valve train assembly of claim 2 wherein the intake cam assembly associated with the second grouping of cylinders comprises the first cam profile that provides a normal mode, the second cam profile that provides a first Miller cycle mode, the third cam profile that provides a second Miller cycle mode.

4. The valve train assembly of claim 3 wherein the first Miller cycle mode comprises a late intake valve closing event.

5. The valve train assembly of claim 1 wherein the first grouping of cylinders comprises a first cylinder, a second cylinder and a third cylinder of the internal combustion engine.

6. The valve train assembly of claim 5 wherein the second axial shifting cam assembly includes three cam assemblies having a central cam assembly that operates as a master actuation system and two outer cam assemblies that operate as slave actuation systems.

7. The valve train assembly of claim 6 wherein the second grouping of cylinders comprise a fourth cylinder, a fifth cylinder and a sixth cylinder.

8. The valve train assembly of claim 1 , further comprising:
an exhaust cam assembly associated with each of the cylinders and having three distinct cam profiles including a first cam profile, a second cam profile and a third cam profile;
a third axial shifting cam assembly movable between a first, second and third axial position corresponding to alignment of the respective three distinct cam profiles of the exhaust cam assembly with exhaust rocker arms associated with the first grouping of the cylinders; and
a fourth axial shifting cam assembly movable between a first, second and third axial position corresponding to alignment of the respective three distinct cam profiles with exhaust rocker arms associated with the second grouping of the cylinders;
wherein the third axial shifting cam assembly operates independently from the fourth axial shifting cam assembly to provide three distinct valve lift profiles on the first grouping of cylinders and three distinct valve lift profiles on the second grouping of cylinders.

9. The valve train assembly of claim 8 wherein the exhaust cam assembly associated with the first grouping of cylinders comprises the first cam profile that provides a normal mode, the second cam profile that provides a cylinder deactivation mode, and the third cam profile that provides an exhaust gas recirculation mode.

10. The valve train assembly of claim 9 wherein the exhaust cam assembly associated with the second grouping of cylinders comprises the first cam profile that provides a normal mode, the second cam profile that provides an early exhaust valve opening mode, the third cam profile that provides an exhaust gas recirculation mode.

11. The valve train assembly of claim 1 wherein the valve train assembly is a Type II valve train.

12. The valve train assembly of claim 1 , further comprising a deactivating lash adjuster having a lost motion device and movable between an activated position where the lost motion device does not absorb a force exerted by the intake rocker arm assembly, and a deactivated position where the lost motion device at least partially absorbs the force exerted by the intake rocker arm assembly.

13. A valve train assembly configured to selectively open and close intake and exhaust valves associated with cylinders of an internal combustion engine, the valve train comprising:
an exhaust rocker arm assembly having a plurality of exhaust rocker arms;
an exhaust cam assembly associated with each of the cylinders and having three distinct cam profiles including a first cam profile, a second cam profile and a third cam profile;
a first axial shifting cam assembly movable between a first, second and third axial position corresponding to alignment of the respective three distinct cam profiles with exhaust rocker arms associated with a first grouping of the cylinders, wherein the first axial shifting cam assembly includes three cam assemblies having a central cam assembly that operates as a master actuation system and two outer cam assemblies that operate as slave actuation systems; and
a second axial shifting cam assembly movable between a first, second and third axial position corresponding to alignment of the respective three distinct cam profiles with exhaust rocker arms associated with a second grouping of the cylinders, distinct from the first grouping of cylinders;
wherein the first axial shifting cam assembly operates independently from the second axial shifting cam assembly to provide three distinct valve lift profiles on the first grouping of cylinders and three distinct valve lift profiles on the second grouping of cylinders.

14. The valve train assembly of claim 13 wherein the exhaust cam assembly associated with the first grouping of cylinders comprises the first cam profile that provides a normal mode, the second cam profile that provides a cylinder deactivation mode, and the third cam profile that provides an exhaust gas recirculation mode.

15. The valve train assembly of claim 14 wherein the exhaust cam assembly associated with the second grouping of cylinders comprises the first cam profile that provides a normal mode, the second cam profile that provides an early exhaust valve opening mode, the third cam profile that provides an exhaust gas recirculation mode.

16. The valve train assembly of claim 13 wherein the first grouping of cylinders comprises a first cylinder, a second cylinder and a third cylinder of the internal combustion engine.

17. The valve train assembly of claim 16 wherein the second axial shifting cam assembly includes three cam assemblies having a central cam assembly that operates as a master actuation system and two outer cam assemblies that operate as slave actuation systems.

18. The valve train assembly of claim 17 wherein t

Assignees

• Eaton Corp

Inventors

• Mccarthy Jr James E
• Wetzel Philip William

Classifications

• F01L1/38

  for engines with other than four-stroke cycle, e.g. with two-stroke cycle (F01L1/26, F01L1/28 take precedence) · CPC title

• F01L2305/00

  Valve arrangements comprising rollers · CPC title

• F01L1/2405

  by means of a hydraulic adjusting device located between the cylinder head and rocker arm · CPC title

• F01L2013/101

  Electromagnets · CPC title

• F01L2013/0052

  with cams provided on an axially slidable sleeve · CPC title