Sealed hydraulic lifter for extreme angle operation

摘要

A hydraulic lash adjuster for an engine is provided that includes a resilient seal received over a plunger assembly above a fluid return aperture in the plunger body. The hollow interior of the pushrod which supplies the hydraulic lash adjuster with fluid provides a secondary low pressure fluid cavity which allows the overall length of the hydraulic lash adjuster to be shortened, thus removing mass from the valve train and improving the valve train dynamics. This configuration prevents fluid from escaping the lash adjuster, allowing the lash adjuster to be positioned in the engine over a wider range of operating angles. Supplying fluid from the pushrod also eliminates the need to machine a fluid supply bore into the body of the hydraulic lash adjuster as well as the need to orient the fluid supply bore to a fluid gallery in the engine block.