Abstract:
A hydraulic lash compensation device for an engine includes a plunger assembly slidingly received within a body bore to define a high pressure chamber. The plunger assembly includes a lower pressure chamber, an upper plunger element, and a lower plunger element. A mechanical lift loss feature includes a generally annular lift stop member retained to the upper plunger element by an adjustment member that extends through the lift stop member and is adjustably received in upper plunger element. The lift stop member is biased away from upper plunger element by a spring. When the upper plunger element is received into the body, the upper plunger element is offset a predetermined distance from the lower plunger element by virtue of the lift stop member's engagement with the lower plunger element. The offset is adjustable based on the position of the lift stop member relative to the upper plunger element.
Abstract:
A hydraulic lash compensation device for an engine includes a plunger assembly slidingly received within a body bore to define a high pressure chamber. The plunger assembly includes a lower pressure chamber, an upper plunger element, and a lower plunger element. A mechanical lift loss feature includes a generally annular lift stop member retained to the upper plunger element by an adjustment member that extends through the lift stop member and is adjustably received in upper plunger element. The lift stop member is biased away from upper plunger element by a spring. When the upper plunger element is received into the body, the upper plunger element is offset a predetermined distance from the lower plunger element by virtue of the lift stop member's engagement with the lower plunger element. The offset is adjustable based on the position of the lift stop member relative to the upper plunger element.
Abstract:
A valve control system for an engine having a camshaft with first and second cam profiles, the valve control system comprising a rocker arm assembly including a first rocker arm having a first cam follower in engagement with the first cam profile, and a second rocker arm having a second cam follower in engagement with the second cam profile. The first rocker arm includes a latch member biased toward a latched condition by a fluid pressure in a chamber, and the first rocker arm defines a fluid passage having a first end in open fluid communication with the pressure source, and a second end in open fluid communication with the pressure chamber. An alignment feature cooperates with the latch member to ensure proper alignment with a latch surface.
Abstract:
A valve control system (15) in which there is provided a deactivating rocker arm (51) disposed beneath a conventional, upper rocker arm (27), and disposed within a module housing (17). The deactivating rocker arm includes a latch tab (63) and when the latch tab engages (FIG. 3) a latch member (65), the system operates in a normal, valve activating mode. When the latch member is in an unlatched condition (FIG. 4), the deactivating rocker arm pivots, compressing the valve return spring (41), which thereafter serves as the required lost motion spring, biasing the deactivating rocker arm (51) and lash compensation device (35) back toward their normal position.
Abstract:
A rocker arm (25) adapted to engage a pair of cam lobes (15,17), the rocker arm having first (31) and second (33) sidewall portions, and being formed from a flat sheet metal blank (25B) having a nominal thickness (T). The sidewall portions (31,33) define fold regions (51,53) whereby, after each is folded over upon itself, and the rocker arm is formed to have the sidewall portions generally parallel to each other, the fold regions provide first (41) and second (43) cam contact surfaces, each having a width (W) substantially greater than the nominal thickness of the blank.
Abstract:
A rocker arm assembly for a valve train includes a hydraulic lash adjuster for accommodating slack in the valve train. There is also a lost-motion connection preferably between the axle of a roller which is operated upon by a cam and the rocker arm itself. Excessive expansion of the lash adjuster will not prevent closing of the valve because the closing movement is accommodated by the lost-motion connection. A spring is provided to maintain the lost-motion connection despite the tendency of the hydraulic lash adjuster to expand. Greater tolerance in the cam base circle radius is allowed, permitting the use of net-shaped cams.