Rocker system, camshaft, and valve train for use with an internal combustion engine
AssigneeCummins Inc.
InventorsGregory J. MITCHUM, Amit Dilip THORAT, Anthony Kyle PERFETTO, Girish Chandra KURA
Life of this patent
Estimating the term…
Abstract
An internal combustion engine system includes an engine with a plurality of pistons housed in respective ones of a plurality of cylinders. A valve train is provided for opening and closing intake and exhaust valves of the cylinders during nominal engine operations. The valve train is also configured to provide for asynchronous switching between selected cam lobe lift profiles for opening and closing of the intake and/or exhaust valves.
Claims20
A rocker system for an internal combustion engine having a camshaft with at least one camshaft lobe, the at least one camshaft lobe including a cam lobe profile with a first portion, a second portion, and a third portion, the rocker system comprising:
- at least one input rocker lever rotatable about an engine component in response to motion received from the at least one camshaft lobe;
- and
- an output rocker lever rotatable about the engine component, and the output rocker lever can be selectively coupled to the at least one input rocker lever to control opening and closing of at least one of an exhaust valve and an intake valve associated with a cylinder of the internal combustion engine, the at least one input rocker is rotated by the first portion of the cam lobe profile to produce a desired lift of the at least one of the exhaust valve and the intake valve while the at least one input rocker lever is coupled to the output rocker lever, wherein the at least one input rocker is rotated by the second portion of the cam lobe profile to misalign the at least one input rocker lever with the output rocker lever to prevent coupling of the at least one input rocker lever and the output rocker lever, and the at least one input rocker lever is rotated by the third portion of the cam lobe profile to align the at least one input rocker lever with the output rocker lever for coupling the at least one input rocker lever to the output rocker lever.
A camshaft for an internal combustion engine having a cylinder and at least one of an intake valve and an exhaust valve associated with the cylinder, the camshaft comprising:
- at least one camshaft lobe configured to control an opening and closing timing of the at least one of the exhaust valve and the intake valve by the at least one cam shaft lobe inducing movement of a rocker lever, the at least one camshaft lobe including a cam lobe profile including:
- a first portion that produces a lift to open the at least one of the exhaust valve and the intake valve through the rocker lever while the rocker lever is associated with the at least one of the exhaust valve and the intake valve;
- a second portion which misaligns the rocker lever to prevent association of the rocker lever with the at least one of the exhaust valve and the intake valve;
- and
- a third portion which aligns the rocker lever for associating the rocker lever to the at least one of the exhaust valve and the intake valve.
A valve train for an internal combustion engine, the valve train comprising:
- one of an intake valve or exhaust valve;
- a camshaft including a camshaft lobe;
- a first rocker lever movable by the camshaft lobe;
- and
- a switch apparatus for selectively coupling the first rocker lever to a second rocker lever, wherein the camshaft lobe includes a lift profile with a first portion that lifts the one of the intake valve or exhaust valve associated with the camshaft lobe through the first rocker lever, a second portion that misaligns the first rocker lever with the second rocker lever, and a third portion that aligns the first rocker lever with the second rocker lever.
A method for operating a rocker system, the method comprising:
- aligning an input rocker lever and an output rocker lever with a camshaft lobe;
- coupling the aligned input rocker lever to the output rocker lever;
- lifting at least one of an intake valve and an exhaust valve with the output rocker lever in response to movement of the input rocker lever induced by the camshaft lobe;
- decoupling the input rocker lever from the output rocker lever;
- and
- misaligning the input rocker lever with the output rocker lever with the camshaft lobe to prevent coupling the input rocker lever to the output rocker lever until the input rocker lever and the output rocker lever are aligned with the camshaft lobe.
Dependencies are inferred from the claim text.