| 摘要 |
What is proposed is a hydraulic lash adjuster ( 1 ), for example for a valve train of an internal combustion engine. The lash adjuster ( 1 ) comprises a hollow cylindrical housing ( 2 ) that is inter-inserted with an axially relatively displaceable pressure piston ( 3 ). A high pressure chamber ( 6 ) for hydraulic medium extends between opposing front ends ( 4, 5 ) of the pressure piston ( 3 ) and the housing ( 2 ). The high pressure chamber ( 6 ) can be supplied, via a one-way valve ( 8 ) arranged on the front end ( 4 ) and opening towards the high pressure chamber ( 6 ) with hydraulic medium out of a reservoir ( 9 ). A leak gap ( 12 ) for the hydraulic medium is formed between an outer peripheral surface ( 10 ) of the pressure piston ( 3 ) and a bore ( 11 ) of the housing ( 2 ). In its portion adjoining the front end ( 5 ) of the housing ( 2 ), the bore ( 11 ) of the housing ( 2 ) merges into an annular enlargement ( 15 ). According to the invention, the front end ( 4 ) of the pressure piston ( 3 ) comprises in its transition region to the outer peripheral surface ( 10 ), a chamfer ( 16 ) whose height (H<SUB>F</SUB>) is equal to or larger than a height (H<SUB>R</SUB>) of the annular enlargement ( 15 ). In this way, it is effectively prevented that undesired particles situated in the high pressure chamber ( 6 ) get deposited on the outer peripheral surface ( 10 ) of the pressure piston ( 3 ) in the sunk state thereof, and penetrate into the leak gap ( 12 ) during the subsequent adjusting operation with the danger of a clamping of the pressure piston ( 3 ).
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