Variable displacement valvetrain systems with rocker shaft porting and insert sleeves for engine cylinder deactivation

A motor vehicle, comprising:

• a vehicle body;
• a plurality of road wheels attached to the vehicle body;
• and
• an internal combustion engine (ICE) assembly attached to the vehicle body and operable to drive one or more of the road wheels to thereby propel the motor vehicle, the ICE assembly including:
• an engine block defining a plurality of cylinder bores,
• a cylinder head mounted onto the engine block and covering the cylinder bores;
• a plurality of pistons each reciprocally movable within a respective one of the cylinder bores;
• a plurality of intake valves movably attached to the cylinder head and each operable to open and close a port to a respective one of the cylinder bores;
• a camshaft rotatably attached to the engine block and bearing a plurality of cams;
• a plurality of pushrods each having a first rod end slidably seated on a respective one of the cams of the camshaft;
• a rocker shaft mounted onto the cylinder head and defining an internal shaft bore configured to receive hydraulic fluid from a feed passage in the cylinder head;
• an oil control valve (OCV) unit attached to the rocker shaft and fluidly coupled to the internal shaft bore to receive therefrom the hydraulic fluid;
• a plurality of rocker arms pivotably mounted onto the rocker shaft and each having a first rocker end mating with a second rod end of a respective one of the pushrods, and a second rocker end mating with a valve stem of a respective one of the intake valves, a subset of the rocker arms each having a respective spring lock unit attached to the first rocker end of the rocker arm and attached to the second rod end of the respective one of the pushrods, each of the spring lock units being fluidly coupled to the OCV unit to receive therefrom the hydraulic fluid to thereby drivingly disengage the rocker arm from the pushrod;
• and
• an insert sleeve mounted inside of the internal shaft bore of the rocker shaft to receive therefrom the hydraulic fluid, the insert sleeve having a feed port transmitting the hydraulic fluid from the insert sleeve to an OCV inlet port of the OCV unit, and a feed pocket transmitting the hydraulic fluid from an OCV outlet port of the OCV unit to the spring lock units of the subset of the rocker arms.

A method of assembling a valvetrain control system for an engine assembly having a cylinder, a valve for opening and closing a port to the cylinder, a camshaft rotatably attached proximate the valve, and a pushrod seated on a cam of the camshaft, the method comprising:

• attaching a rocker shaft to the engine assembly, the rocker shaft including an internal shaft bore configured to receive hydraulic fluid;
• attaching an oil control valve (OCV) unit to the rocker shaft;
• fluidly coupling the OCV unit to the internal shaft bore of the rocker shaft to receive therefrom the hydraulic fluid;
• pivotably mounting a rocker arm onto the rocker shaft;
• mating a first rocker end of the rocker arm with the pushrod;
• mating a second rocker end of the rocker arm with the valve;
• attaching a spring lock unit attached to the first rocker end of the rocker arm to the pushrod;
• fluidly coupling the spring lock unit to the OCV unit to receive therefrom the hydraulic fluid to thereby drivingly disengage the rocker arm from the pushrod;
• and
• mounting an insert sleeve in the internal shaft bore to receive the hydraulic fluid from the rocker shaft, the insert sleeve including a feed port transmitting the hydraulic fluid from the internal shaft bore and the insert sleeve to an OCV inlet port of the OCV unit, and a feed pocket transmitting the hydraulic fluid from an OCV outlet port of the OCV unit to the spring lock unit.