Valve bridge systems include constraints and guides for managing bridge jump and other uncontrolled valve bridge motion during engine operation. Constraints may include an e-foot collar, an extended portion on the bridge, and a bridge brake pin. Guides may include valve stem tip lead-in chamfers surrounding the valve bridge valve pockets as well as a deflection surface on the bridge extended portion. Methods of configuring valve bridges may include configuring the valve step tip lead-in chamfers based on worst-case positions of the valve bridge defined by one or more or a combination of the constraints provided by the e-foot collar, extended portion and brake pin.

An internal combustion engine includes an electro-hydraulic system for variable actuation of intake valves where each cylinder has two intake valves, associated with two intake conduits. A first conduit is generates within the cylinder a tumble motion of airflow introduced therein, when the intake valve associated thereto is at least partially opened. The second intake conduit generates within the cylinder a swirl motion of airflow introduced therein when the second intake valve is at least partially opened. A controller of controls one or more control valves to open only one of the intake valves of each cylinder in a condition of reduced engine operation, below a predetermined load and/or a predetermined speed of the engine, and to always open both intake valves in the remaining conditions of engine operation. The first intake valve is the only valve to be opened in the reduced engine operation condition.

A decompression shaft (56) of a decompression device (50) includes an engagement pin (53) that is guided by a guide groove (51a) formed in a decompression weight (51), a decompression cam (54) that is provided on one cam surface of an intake valve cam (25c) and an exhaust valve cam (25b) so as to advance and retreat, and a connection portion (55) that connects the engagement pin (53) and the decompression cam (54). The decompression weight (51) is formed with a rotation restricting groove (51e) that restricts rotation of the decompression shaft (56) when a force acts in a direction in which the decompression cam (54) moves on the decompression shaft (56) from an advanced position to a retracted position when an engine (E) is stopped and that is continuous with the guide groove (51a).

A mechanical seal clamping assembly includes a base, a fulcrum, a lever, and a cap. The base supports a mechanical seal. The lever is pivotally coupled to the fulcrum at a first pivot spaced from the base. The cap is coupled to the lever and is movable by the lever with respect to the base. The cap is movable from a first position to a second position. In the first position, the cap is at a first distance away from the base. In the second position, the cap is at a second distance away from the base larger than the first distance. The lever moves the cap from the second position toward the first position to engage the mechanical seal to clamp, between the cap and the base, the mechanical seal to maintain a spring of the mechanical seal compressed during assembly or disassembly of the mechanical seal.

A system for controlling actuation of an engine valve comprises a pivot and a torsion spring having first and second legs operatively connected to the pivot. A lever arm is adjustably affixed to and extending away from the pivot, and is further rotatable about a pivot axis of the pivot between a retracted position and an extended position and vice versa relative to a motion conveying component. Furthermore, a housing is provided having a pivot bore formed therein with the pivot rotatably disposed in the pivot bore. The housing further comprises a first and second openings intersecting with the pivot bore such that the first and second legs extend out of the first opening and the lever arm extends out of the second opening. When a first force is applied by the motion conveying component to the lever arm, such first force maintains the lever arm in the extended position.

A mechanical seal clamping assembly includes a base, a fulcrum, a lever, and a cap. The base supports a mechanical seal. The lever is pivotally coupled to the fulcrum at a first pivot spaced from the base. The cap is coupled to the lever and is movable by the lever with respect to the base. The cap is movable from a first position to a second position. In the first position, the cap is at a first distance away from the base. In the second position, the cap is at a second distance away from the base larger than the first distance. The lever moves the cap from the second position toward the first position to engage the mechanical seal to clamp, between the cap and the base, the mechanical seal to maintain a spring of the mechanical seal compressed during assembly or disassembly of the mechanical seal.

A variable valve driving mechanism of an engine, and the engine. The variable valve driving mechanism comprises a rocker arm (1) configured to control open and close of a valve (7) and a servo rocker arm (2) arranged in parallel to the rocker arm (1). A swing end of the servo rocker arm (2) extends to the top of the swing end of the rocker arm (1). A valve adjustment gap (1-2) provided in the swing direction of the servo rocker arm (2) and the rocker arm (1) is formed between the servo rocker arm (2) and the rocker arm (1). A gap compensating device telescopically filling the valve adjustment gap (1-2) and configured to adjust the valve (7) to be delayed to close or open in advance when extending to the valve adjustment gap (1-2) is provided between the servo rocker arm (2) and the rocker arm (1). When the valve (7) is open or closed normally, the gap compensating device is contracted, and the rocker arm (1) is not in contact with the servo rocker arm (2) in the swing process by means of the valve adjustment gap (1-2). When it is required to control the valve (7) to be delayed to close or open in advance, the gap compensating device extends into the valve adjustment gap (1-2) to eliminate the gap, and the open/close time of the valve (7) is adjusted to avoid the problem that the valve is not properly closed caused by a plurality of oil control paths.

Systems and methods for intermittent supply of lubricating oil to a tip of a rocker arm assembly. In one embodiment, a lubricating oil may be selectively to a tip of a rocker arm via oil channels aligned only during opening of a valve coupled to the tip.

Some embodiments of a present disclosure provide a variable valve lift device. The variable valve lift device includes a main shaft, a sleeve, an oil cylinder and a valve mechanism. The sleeve is provided on the main shaft in a sleeve manner, can be driven by the main shaft to rotate together with the main shaft, and can further linearly move relative to the main shaft along an axis direction of the main shaft. A cam assembly is disposed on the sleeve, and includes at least two cams with different projection heights. The oil cylinder includes a cylinder barrel and a piston disposed in the cylinder barrel, the cylinder barrel is fixed onto the main shaft, the piston is fixedly connected to the sleeve. Some embodiments of the present disclosure provide an automobile having the above variable valve lift device.

A cover body (2) for a valve rotating device includes a ring-shaped upper part (4) and a ring-shaped lower part (6). The upper part (4) and the lower part (6) are axially spaced apart and are adapted to accommodate an axial spring element (24) therebetween. The upper part (4) and the lower part (6) are connected to one another by at least one connecting piece arranged at the location opposite an insertion position of the axial spring element (24).

A valve rotating device (12) having such a cover body is also provided. A ring-shaped base body (22) hasg a plurality of pockets (16) oriented in a circumferential direction, in each of which a ball (14) and a tangential spring (32) are arranged. The pockets (16) have a variable depth in the circumferential direction such that inclined raceways (26) for the balls (14) arranged therein are formed. The tangential springs (32) push the balls (14) toward an end of the respective pocket (16). The axial spring element (24) is ring-shaped and a first end of the axial spring element (24) is supported on an ring-shaped stop surface (18) of the base body (22) and a second end of the axial spring element (24) is supported on a surface of the upper part (4) of the cover. A surface of the lower part (6) facing away from the axial spring element (24) rests against the balls (14), and wherein the balls (14) and the axial spring element (24) are arranged overlapping in the radial direction.

A method for producing a cover body (2) for a valve rotating device is also provided.