Valve clearances
Due to the use of hydraulic pushers (valve clearance compensators) no need to check or adjust valve clearances.
Hydraulic tappets
Hydraulic pushers are located at the end of the rocker arms and transmit force to the ends of the valve stems.
Operation
Oil enters under pressure into the central channel of the rocker axis (1, fig. 2.1), follows from it at the point (2), prote-. flows between the rocker arm and the oil line, enters the lubrication channel of the rocker arm (3), passes through the support washer and enters the hydraulic pusher. The hydraulic pusher consists of the following elements:
- housing (1, fig. 2.2), in contact with the valve stem;
- hydraulic plunger (2);
- ball valve (3). springs (5) and support washer (4);
- return spring (5);
- oil chamber (A);
- high pressure chambers (IN);
- plunger movement zones (WITH).
Pic. 2.1. Oil supply to hydraulic tappet: 1 - channel of the rocker axis; 2 - point of oil leakage from the rocker arm axis; 3 - rocker arm lubrication channel
Pic. 2.2. Hydraulic pusher:1 - body; 2 - hydraulic plunger; 3 - ball; 4 - spring; 5 - crucible; A - oil chamber; B - high pressure chamber; C - plunger movement zone
Gap adjustment phase
Spring (5) Maintains close contact with all parts of the hydraulic tappet that provide oil supply. Oil under pressure of the lubrication system located in the chamber (A), opens the ball (3) and fills the high pressure chamber (IN) in such a way that any increase in valve clearance will be systematically compensated. After filling the chamber (IN) spring (4) presses the ball (3) to its socket and prevents oil from leaking out of the high pressure chamber.
Compression
When the camshaft cam actuates the rocker arm, it through the plunger (2) and the volume of oil in the high pressure chamber (IN), presses the pusher body. To compensate for the volume of oil, which, under pressure, removes all valve clearances, a small amount of oil flows through the gap between the plunger (2) and body (1) pusher. On the other hand, air escapes through this gap and ensures normal functioning of the pusher when starting the engine.