An engine assembly is provided. The engine assembly comprises an oil system comprising: a first oil pump configured to supply oil at a first pressure to one or more first components of the engine assembly; and a second oil pump configured to supply oil at a second pressure to one or more second components of the engine assembly, the second pressure being higher than the first pressure; wherein the second oil pump is provided adjacent to a valve train of the engine assembly.

The variable valve actuating device (20) comprises a valve lifter (24) interposed between a swing end of a rocker arm 22 and a stem end of an engine valve (17), and a switch pin (53) slidably received in the valve lifter (24) so as to selectively abut the end surface of the valve stem as the valve lifter is actuated by a cam (21a). The swing end of the rocker arm abuts an upper end of a projection (55) projecting from the upper end of the valve lifter via an engagement feature (26b, 55a) that prevents a rotational movement of the valve lifter relative to the swing end around the axial line of the valve stem.

A valve actuation system for an internal combustion engine is disclosed. The engine has a first set of cylinders having a first set of exhaust valves and a second set of cylinders having a second set of exhaust valves. The valve actuation system for the exhaust valves includes one or more first cams having a compression-release lobe and a main exhaust lobe adapted to transfer valve actuation motion to the first set of exhaust valves, and one or more second cams having an early exhaust valve opening (EEVO) lobe and a main exhaust lobe adapted to transfer valve actuation motion to the second set of exhaust valves. The valve actuation system may provide any combination of (i) main exhaust valve actuation with or without compression release actuation with (ii) main exhaust valve actuation with or without EEVO for the two sets of cylinders.

A valve actuation system for an internal combustion engine is disclosed. The engine has a first set of cylinders having a first set of exhaust valves and a second set of cylinders having a second set of exhaust valves. The valve actuation system for the exhaust valves includes one or more first cams having a compression-release lobe and a main exhaust lobe adapted to transfer valve actuation motion to the first set of exhaust valves, and one or more second cams having an early exhaust valve opening (EEVO) lobe and a main exhaust lobe adapted to transfer valve actuation motion to the second set of exhaust valves. The valve actuation system may provide any combination of (i) main exhaust valve actuation with or without compression release actuation with (ii) main exhaust valve actuation with or without EEVO for the two sets of cylinders.

A valve switching apparatus includes a rocker arm coming into contact with a cam to open and close a valve along with a rotation of the cam, and an eccentric generation means provided to the rocker arm so as to allow an eccentric position to be changed by rotation thereof.

A variable valve mechanism includes an input arm that axially supports a roller pressed by a cam, via a roller pin, an output arm that drives a valve when swinging, a switch device that switches the variable valve mechanism between a coupled state where the both arms are coupled and an uncoupled state where the arms are uncoupled from each other, and a lost motion spring that biases the roller against the cam when in the uncoupled state. The lost motion spring includes an extended portion extending in an inter-arm clearance between the input arm and the output arm. An end of the roller pin projects from the input arm into the inter-arm clearance by such a length that the end is accommodated in the inter-arm clearance and that allows a spring retaining portion to be formed in the end. The spring retaining portion is formed in the end.

A variable valve mechanism includes an input arm that axially supports a roller pressed by a cam, via a roller pin, an output arm that drives a valve when swinging, a switch device that switches the variable valve mechanism between a coupled state where the both arms are coupled and an uncoupled state where the arms are uncoupled from each other, and a lost motion spring that biases the roller against the cam when in the uncoupled state. The lost motion spring includes an extended portion extending in an inter-arm clearance between the input arm and the output arm. An end of the roller pin projects from the input arm into the inter-arm clearance by such a length that the end is accommodated in the inter-arm clearance and that allows a spring retaining portion to be formed in the end. The spring retaining portion is formed in the end.

Embodiments are directed toward an engine. In some embodiments, the engine includes a water pump and a balancer shaft. In some embodiments, the water pump has a plain bearing. In some embodiments, plain bearing is supplied with pressurized oil. In some embodiments, the balancer shaft drives the water pump as well as cam shafts.

A columnar-type hydraulic tappet, provided with a housing, a plunger moving axially with respect to the housing being mounted in an inner cavity of the housing, a high pressure cavity used for a hydraulic medium extending between a lower end surface of the plunger and a lower side of the housing, a first ring groove being arranged below a head portion of the plunger, a second ring groove being arranged at a central portion of the plunger, a plunger central wall being between the first ring groove and the second ring groove, the second ring groove being a concave wide ring groove, wherein at least one plunger oil inlet hole being arranged on the plunger concave wide ring groove or the plunger central wall, a bottom portion edge of the plunger oil inlet hole containing flanging facing towards an inner cavity of the plunger.

An internal combustion engine has a valvetrain that includes a rocker arm assembly on which is mounted an electronic device and at least a part of a generator. The generator converts some of the mechanical energy that is transmitted through the rocker arm assemblies into electricity. That electricity may be used to power an electric latch, a transmitter, or another type of rocker arm assembly-mounted electrical device. Various generator configurations are described. In some configurations, the generator is piezoelectric. In other configurations, the generator is electromagnetic. In some configurations, the generator is driven by force transmitted by the rocker arm assembly from a cam. In some configurations, the generator is driven by vibrations.