134 results about "Hydraulic clearance" patented technology

Systems and methods for actuating engine valves for positive power and engine braking operation are disclosed. The systems may include a self-lashing hydraulic piston slidably disposed in a fixed or rocker arm housing. The hydraulic piston may have an internal cavity in which a motion absorbing piston is disposed. A hydraulic fluid source may communicate with the hydraulic piston bore. A check valve which may be incorporated in a control valve may controls hydraulic fluid supply from the hydraulic fluid source to the hydraulic piston to provide self-lashing operation of the valve actuation system.

In a Type 2 engine, a valve deactivation hydraulic lash adjuster (DHLA) in accordance with the invention replaces a conventional hydraulic lash adjuster in the train of a gas-exchange valve in a compression-ignited engine. In a Type 3 engine, a similar DHLA is disposed within an articulated rocker arm which is made selectively competent (valve activating) or incompetent (valve deactivating) thereby. A solenoid valve within the assembly diverts hydraulic fluid between support and non-support of a piston slidably disposed in a housing and terminating in a ball head. The valve is force-balanced. The preferred hydraulic fluid is diesel fuel, allowing for smaller diameter passages and cleaner operation than in prior art systems, eliminating the need for an accumulator chamber and accumulator piston as in the prior art. An alternate version of a type 3 engine having a DHLA, in accordance with the invention, is also shown.

An improved dual feed hydraulic lash adjuster (HLA), for use in an internal combustion engine, comprising a hollow body and a plunger assembly disposed in a bore of the engine. A one-piece plunger body includes a first chamber for forming a low-pressure oil reservoir and receiving a lash adjustment mechanism, and a second chamber open at one end and partially closed hemispherically for supporting a rocker arm and providing valve deactivating oil thereto for an auxiliary valve actuation system. The first and second chambers are separated by a transverse web, optionally having a small-diameter passage therethrough for air evacuation. The one-piece plunger body provides a high degree of resistance to side loads which may be imposed on the HLA in use.

A two-step roller finger follower assembly for shifting between high-lift and low-lift valve modes in a valve train of an internal combustion engine includes a body having side members defining coaxially disposed shaft orifices, a pallet end, a socket end, a slider arm aperture, and a latch pin channel. The socket end is mountable to a hydraulic lash adjuster, and the pallet end is matable with a valve stem. A slider arm for engaging a high-lift cam lobe is disposed in the aperture, is pivotably mounted to a rotatable cross-shaft extending through the shaft orifices, and includes a slider tip for selectively engaging a latch pin to latch or unlatch the slider arm from the body. Dual rollers on the cross-shaft follow dual low-lift cam lobes. Preferably, the slider arm has a compound radial surface to provide compound lost motion of the slider arm, thereby minimizing rotational inertia.

The invention relates to a driving oil way of a variable valve mechanism with VVT and VVL system. The driving oil way comprises a VVT oil way, a cam shaft journal lubricating oil way, a hydraulic clearance adjuster oil way, a VVL system control oil way and one-way valves (6), wherein the VVT oil way is arranged in the middle of a cylinder cover; the cam shaft journal lubricating oil way is arranged on the two sides of the cylinder cover; the VVL system control oil way is integrated in the hydraulic clearance adjuster oil way; and a plurality of one-way valves (6) are arranged between a VVT oil way inlet (4) on the oil way of the cylinder cover and an engine oil control valve OCV (11) of the VVT system, and opened when the VVT system works normally and closed when an engine is stopped or idles.

An engine includes a hydraulic pressure lash adjuster (HLA) pivotally supporting an end of a swing arm and having a valve supporting the other end of the swing arm, wherein the hydraulic pressure lash adjuster includes a housing, a plunger of which one end portion thereof may be slidably inserted into the inside of the housing, the other end portion of which extends outwards and supports the end of the swing arm by selectively moving upwards or downwards in a length direction of the housing, a stopper pin slidably mounted in a chamber of the plunger so as to selectively lock the plunger to the housing such that the plunger cannot move in the housing, and a hydraulic pressure supply portion that selectively supplies one side of the stopper pin with a hydraulic pressure in the chamber of the plunger to move the stopper pin toward the housing.

The valve train assembly with magnet uses the magnet to collect ferrous metal particles that are in the oil prior to their arrival at the high pressure cavity of the hydraulic lash adjuster. The magnet can be positioned in the low pressure cavity of the hydraulic lash adjuster, in the bore of the hollow rocker arm shaft or in the bore of the hollow push rod.

A dual feed hydraulic lash adjuster includes a plunger assembly slidingly disposed in a lash adjuster body and having an end adapted to cooperate with a valve actuating mechanism, the plunger assembly forming a low-pressure first chamber and a high-pressure second chamber with the body, the plunger assembly having a first aperture fluidly communicating with the first chamber, a passageway fluidly communicating with the first chamber, and a second aperture fluidly communicating with the passageway, and a separate fluid pressure separator disposed in the plunger assembly between the first aperture and the second aperture to prevent passage of hydraulic fluid between the first chamber and the passageway, wherein a passage is provided through the fluid pressure separator to provide for evacuation of air from the lash adjuster.

In an internal combustion engine comprising two or more engine valves that receive valve actuation motions from a valve actuation motion source via a valve train, which valve train comprises a hydraulic lash adjuster, an apparatus for valve actuation comprises a valve bridge and a lost motion assembly disposed therein. The lost motion assembly comprises a first piston disposed in a first piston bore formed in the valve bridge. The first piston is configured to operatively connect with a component of the valve train. A biasing element is configured to bias the first piston out of the first piston bore with a first force that is greater than a second force applied to the first piston by the hydraulic lash adjuster. A travel limiter is configured to limit travel of the first piston out of the first piston bore to be no greater than a maximum lost motion distance.

A cold-formed ball plunger blank is provided for use in manufacturing a finished ball plunger used in a hydraulic lash adjuster that includes a check valve assembly having a check ball and a retainer. The ball plunger blank includes a cup-shaped member that extends from a first end to a second end along a longitudinal axis. The cup-shaped member includes a ball portion adjacent the first end of the member and a body portion adjacent the second end of the member. The body portion has a cavity disposed therein, a counterbore extending from the second end of the body towards the first end of the member, and a shoulder that separates the cavity from the counterbore and at least partially closes the cavity. The shoulder defines a ball seat surface configured to receive the check ball and a retainer receiving surface configured to receive the retainer, wherein the ball seat surface and the retainer receiving surface are to sized to the final dimensions of the finished ball plunger. The invention also relates to a method of cold-formed ball plunger blank.

An engine that may be provided with a variable valve device may include an hydraulic pressure lash adjuster pivotally supporting one side of a swing arm, a valve supporting the other side of the swing arm, and an operating portion pushing a portion of the swing arm downwards so as to pivotally move the valve based on the hydraulic pressure lash adjuster, wherein the hydraulic pressure lash adjuster includes a housing in which an insertion hole may be formed therein, a slave piston that may be slidably inserted into the insertion hole, a master piston of which an end thereof may be placed into the insertion hole with a predetermined gap from the slave piston, wherein the other end of the master piston protrudes out of the housing and may be engaged with the one side of the swing arm, and an oil control valve that opens or closes a passage communicating with a master chamber that may be formed between the master piston and the slave piston in the housing.

A valve bridge configured to engage an engine valve is disclosed. The valve bridge includes a bridge cavity formed within a center portion of the valve bridge and including a bottom surface. A hydraulic lash adjuster is slidably disposed within the bridge cavity.