Caterpillar Inc.

Michael Dean Roley

Jeffrey Clark Krieger

Quinton Burcar

Kyle Michael Rader

Stephan Donald Roozenboom

Matthew Thomas Wolk

Rong Qu

John R McDonald

Paul Kenneth Stark

Ram Prasanth Anjaneyulu

Ry C Colwell

Douglas D Erdman

Operating an engine includes opening and closing exhaust valves in an engine braking timing pattern, charging a first cylinder with air fed directly from an intake manifold, and releasing the directly fed air in a first braking event. Operating the engine further includes charging the first cylinder with air fed via a flow-through path through a second cylinder operating as an air conduit, and releasing the air fed through the flow-through path and pressurized to brake the engine in a second braking event. Related apparatus and valve lift profiles are also disclosed.

Engine braking strategy using cylinder flow-through path for optimizing braking power

A spacer for a valvetrain in an engine system includes a spacer body defining a spacer axis extending between a first axial spacer body end and a second axial spacer body end, and including an outer peripheral surface, a circumferentially extending inner peripheral surface forming a through-bore, an oil spray port extending from the inner peripheral surface to the outer peripheral surface, and a circumferentially extending fluid groove formed in the inner peripheral surface and extending to the oil spray port. Related valvetrain and rocker arm assembly apparatus is also disclosed.

Spacer equipped to spray oil and rocker arm assembly for valvetrain

An engine valve includes a stem, a head comprising an outer lip surface, a seating surface extending from the outer lip surface toward the stem, and a combustion surface extending from the outer lip surface on the opposite side of the head as compared to the seating surface. The combustion surface includes a first convex arcuate surface spaced away from the outer lip surface, at least partially forming a raised ring, and a first concave arcuate surface spaced away from the outer lip surface, at least partially forming a dimple.

Engine valve with raised ring or dimple

An engine valve actuation system includes a hydro-mechanical valve actuation module having a first hydro-mechanical linkage and a second hydro-mechanical linkage, each within a different housing block of a housing. Each of the first hydro-mechanical linkage and the second hydro-mechanical linkage includes a cam-follower piston in contact with a cam of a camshaft, and a valve-actuation piston hydraulically co-acting with the respective cam-follower piston. The hydro-mechanical valve actuation module may include hydro-mechanical linkages for an intake valve, for an exhaust valve, and for engine braking.

Hydro-mechanical module for engine valve actuation system

An engine head assembly includes a valve seat insert having a valve seating surface defining a center axis, and each of an inner peripheral surface and an outer peripheral surface extending circumferentially around the valve seat center axis. The outer peripheral surface includes an upper section interference-fitted with the engine head, and a lower section. A stiffness relief channel is formed by a relief cutout in the valve seat insert, and extends radially between the lower section of the outer peripheral surface and the engine head. The stiffness relief channel permits flexing of the valve seat insert to cushion valve seating to prolong engine valve and valve seat insert service life.

Engine head assembly with valve seat insert with stiffness relief cutout

A system for lubricating a valve assembly of an engine. The system includes a valve bridge having a base portion is disposed on a guide rod. The guide rod is received within a hole defined in the base portion of the valve bridge to define a chamber and to receive lubricant in the chamber. The valve bridge includes an arm that is engaged with a valve stem. The valve bridge includes a passage in fluidly communicating with the chamber and an end of the arm. The system includes a valve disposed around the valve stem and valve stem guide. The valve seal includes a lip member that abuts an outer surface of the valve stem to control a flow of the lubricant from the passage to a gap defined between the valve stem and the valve stem guide.

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Washington, IL, United States of America

Michael Dean Roley