A method for estimating wear of at least one component of an internal combustion engine includes receiving sensor information and fuel commands indicative of an amount of fuel supplied to at least one combustion chamber of the internal combustion engine and determining an incremental increase in an amount of wear of at least one component of the internal combustion engine based on at least the sensor information and the fuel commands. The method also includes determining an updated amount of wear based on the incremental increase in the amount of wear, and outputting a notification indicative of the updated amount of wear.

A method for estimating wear of at least one component of an internal combustion engine includes receiving sensor information and fuel commands indicative of an amount of fuel supplied to at least one combustion chamber of the internal combustion engine and determining an incremental increase in an amount of wear of at least one component of the internal combustion engine based on at least the sensor information and the fuel commands. The method also includes determining an updated amount of wear based on the incremental increase in the amount of wear, and outputting a notification indicative of the updated amount of wear.

Even in the case where, due to distortion (undulation) or the like of an end surface of an adjusting screw abutting on a valve stem end, there exists a non-linear undulation movement amount in a movement amount of the end surface with respect to a rotation return angle of the adjusting screw, the undulation movement amount is continuously measured, and a screw return movement amount based on a screw pitch and on the rotation return angle is continuously calculated, and, when a total movement amount of the undulation movement amount and the screw return movement amount has attained a prescribed clearance, return rotation is ended.

A rocker arm for use in a valvetrain of a vehicle, having a body portion including two opposed side wall portions, each defining a bearing aperture therein and including a bearing boss disposed along a perimeter of the corresponding bearing aperture. A support bearing has a pair of opposed ends, each opposed end being received in a corresponding bearing aperture, and each bearing boss includes a first portion having a first radial thickness and a second portion having a second radial thicknesses, the first radial thickness being greater than the second radial thickness.

A method of two-step variable valve lift (VVL) malfunction avoidance learning control may include: in a two-step VVL system which is operated with a main lift and a secondary lift, verifying, by an electronic control unit (ECU), an operation avoidance area based on locking of a lock pin of a cam follower ; performing VVL operation learning, in which a failure of occurrence of the second lift is determined on the basis of a locking failure of the cam follower due to an initially set value of the operation avoidance area; and reflecting the operation avoidance area to the two-step VVL system with a corrected set value which is obtained through the VVL operation learning.

In order to ensure a simple, reliable and recuperative operation in a hydraulic drive (10) for accelerating and braking a gas exchange valve (20) of internal combustion engines or other reciprocating engines, it is proposed that a first pressure reservoir (41) for providing a first pressure p.sub.1 comprises a restoring energy accumulator, preferably configured as a spring (25), and at least one hydraulic base pressure reservoir (40), which has a lower pressure p.sub.0 than the first pressure reservoir (41). In a connecting line (48) between the first hydraulic pressure reservoir (41) and the working cylinder (22), a controllable opening (49) of a first valve (46) comprising at least one check valve (47) is arranged upstream or downstream in the flow path, which allows the pressure medium (30) to flow in the direction of working cylinder (22), but prevents a backflow towards the pressure reservoir (41).

In order to also initiate the closing movement or to enable the breaking of the gas exchange valve in a hydraulically simple and reliable manner, in a second connecting line (58) between the first pressure reservoir (41) and the working cylinder (22) there is arranged a controllable opening (59) of a second valve (56) comprising a check valve (57), which prevents a flow in the direction of the working cylinder (22), but allows a return flow in the direction of the pressure reservoir (41).

In a hollow exhaust poppet valve including a fillet increasing in diameter toward a leading end, a stem, and a head and having a coolant within a hollow part formed from the head to the stem, the stem includes a first stem part on a base end side, and a second stem part integrated with the first stem part via a step part and integrated with the fillet, and the hollow part includes a first hollow part formed inside the first stem part, and a second hollow part formed inside the second stem part, the fillet, and the head in such fashion as to have a constant inner diameter greater than the first hollow part and formed so as to be continuous with the first hollow part via a tapered part or a curved part.

An internal combustion engine includes a cam-actuated rocker arm assembly with a solenoid-actuated latch that provides for cylinder deactivation or variable valve actuation. The solenoid has an inductance that varies significantly in relation to the position of a latch pin as it translates between latching and non-latching configurations. A sensor is positioned to monitor a current or a voltage in a circuit that includes the solenoid. Diagnostic information relating to the operation of the rocker arm assembly is determined by comparing data collected from the sensor over a first period to data collected from the sensor over a second period.

A high efficiency uniflow steam engine having automatic poppet valves yieldably based by fluid such as steam held under pressure within a cavity in the engine and a cutoff control for closing a steam inlet valve at any time selected stops the flow of steam into the cylinder. Proximate the end of the exhaust stroke, around 0.12 inch before TDC the cylinder is sealed to thereby compress residual steam as the piston clearance approaches zero; typically, 0.020 inch which raises cylinder pressure enough to open an inlet valve without making physical contact to push the inlet valve open with the piston thereby eliminating a tappet type of noise, shock and wear.

An engine with a reduced cooling loss, may include a cylinder block, a piston and a cylinder head, wherein the engine displacement chamber is 300cc-700cc and an entire combustion chamber volume including a first volume of the cylinder block and a second volume of the cylinder head is defined between an inner surface of the cylinder head, a distal end of an intake valve mounted in the cylinder head when the intake valve is closed, and an upper surface of the piston positioned at a top-dead center of the engine in the cylinder block, wherein a compression ratio between an engine displacement chamber and the entire combustion chamber is 10.0 or more:1, and wherein the second volume of the cylinder head is 40%-70% of the entire combustion chamber volume.