Hydraulic lash adjuster with oil reservoir separator

Abstract

A hydraulic lash adjuster for valve gear of an internal combustion engine, the hydraulic lash adjuster being of the type which operates from oil received under pressure from a gallery provided in the engine lubricant supply system to compensate for lash in the valve train. The body of the lash adjuster has a movable plunger assembly provided therein including upper and lower plunger members each having a bore therein which define upper and lower fluid reservoirs, respectively. A one way check valve is located between the lash adjuster body and the lower plunger member. A thin walled, cup shaped metal separator is received in the lower end of the upper plunger member for fluidly isolating the fluid reservoirs. The separator member is held in place by a plurality of outwardly turned retaining tabs extending from the open end thereof which engage the upper end of the lower plunger member. Annular metering passages meter the pressurized engine oil for supplying fluid to the lower and upper fluid reservoirs. A passageway in the top end of the upper plunger member conveys fluid from the upper fluid reservoir to a reaction surface located on the upper plunger member.