Engine and valvetrain with dual pushrod lifters and independent lash adjustment
AssigneeFord Global Technologies, LLC
InventorsMatthew Diggs, Wally Beaber, Robert Innes
Life of this patent
Estimating the term…
Abstract
A multiple cylinder internal combustion engine having a camshaft-driven valvetrain with a camshaft disposed within an engine block includes at least two intake and/or exhaust valves with a pair of valves operated by a common camshaft lobe and a cam follower. The valvetrain may include independently operable mechanical or hydraulic lash adjusters. The cam follower contacts the common camshaft lobe and at least two pushrods with each pushrod having an associated single plane rocker arm which couples to a fulcrum mounted to the cylinder head to actuate the at least two valves.
Claims19
A multiple cylinder internal combustion engine having a camshaft-driven valvetrain with a camshaft disposed within an engine block, the engine including at least two valves operated by a common camshaft lobe, the engine comprising:
- a cam follower in contact with the common camshaft lobe and at least two pushrods, each pushrod associated with one of the at least two valves;
- a first rocker arm associated with a corresponding pushrod and having a first length and a first pivot point defining a first rocker ratio corresponding to distance between an associated pushrod and the first pivot point relative to distance between an associated valve stem and the first pivot point;
- and
- a second rocker aim associated with a corresponding pushrod and having a second length and a second pivot point defining a second rocker ratio corresponding to distance between an associated pushrod and the second pivot point relative to distance between an associated valve stem and the second pivot point, wherein the first and second lengths are substantially different and the first and second rocker ratios are substantially identical.
A valvetrain for a multiple cylinder internal combustion engine having a camshaft disposed within an engine block for operating two valves to both open or close independently and substantially simultaneously from a single camshaft lobe, the valvetrain comprising:
- a lifter having a roller for contacting the single camshaft lobe and including first and second lash adjusters;
- first and second rocker arms each associated with a respective one of the two valves;
- and
- first and second pushrods extending between respective first and second lash adjusters and first and second rocker arms, the first and second pushrods moving in the same direction substantially simultaneously to open or close respective valves.
A lifter for an internal combustion engine having a pushrod valvetrain with a camshaft disposed within an engine block, the lifter comprising:
- a housing;
- a roller for contacting a camshaft lobe, the roller being mounted for rotation about an axle mounted in the housing;
- and
- first and second hydraulic lash adjusters each at least partially disposed within the housing and having one end adapted for coupling with a corresponding one of first and second pushrods to move the first and second pushrods in the same direction substantially simultaneously in response to movement of the housing, the first and second hydraulic lash adjusters each including a variable volume chamber fillable with hydraulic fluid to adjust axial distance of the corresponding pushrod relative to the housing and the roller.
Dependencies are inferred from the claim text.