Hydraulic Tappet

The working principle of hydraulic tappet:
1. The work of the hydraulic tappet mainly depends on the oil pressure, the clearance between the tappet body and the seat hole, the clearance between the valve rod and the tappet column and the check ball valve in the tappet column. When the hydraulic tappet starts to work, because there is no oil pressure in the cavity, the tappet plunger is at the very bottom, and the clearance between the tappet and the valve is large, and the valve produces short-term abnormal sound;
2. With the operation of the engine, under the action of oil pressure, the oil is filled in the plunger cavity in the tappet, the plunger goes down, the effective working length of the tappet increases, and the valve clearance decreases;
3. Because the force generated by the plunger in the tappet is small, the force of the compressed valve spring cannot be generated, so when the clearance between the tappet and the valve is very small, the tappet no longer moves;
4. At the same time, due to the role of the check ball valve in the tappet, the oil pressure in the plunger cavity can not be quickly discharged, so that the plunger remains in place and maintains the original length to form rigidity, thus pushing the valve to open. With the operation of the engine, the valve clearance maintains a certain gap to eliminate the abnormal valve noise.

The work of the hydraulic tappet mainly depends on the oil pressure, the clearance between the tappet body and the seat hole, the clearance between the valve rod and the tappet post and the check ball valve in the tappet post. The role of the tappet is to transmit the thrust of the camshaft to the push rod (or valve rod) and to withstand the lateral force exerted by the camshaft as it rotates. The tappet is fitted with adjusting screws at its top to adjust the valve clearance.