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Hydraulic valve lifters compensators
| Fig. 114. Hydropusher valves: 1 - Rocker; 2 - a lock ring; 3 - a washer; 4 - cap; 5 - the push rod; 6 - the directing plug; 7 - Ball guide channel; 8 - a ball diameter of 4 mm; 9, 10 - compression springs; 11 - ball socket; 12 - the valve spring plate; 13 - the valve; a - oil chamber; b - the working chamber; c - return channel leakage; f - an annular groove; h - the oil passage
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The problem of hydraulic jacks pushers of valves is to compensate for valve clearance, which changes due to thermal expansion and the wear and tear of the valve timing. The rocker arms are in constant contact with the camshaft, so the noise of the valve mechanism is maintained at a low level. Hydraulic jacks mounted in rocker arms and act on the valve through the ball socket 11 (Fig. 114). The system of hydraulic valve clearance compensation consists of the following elements: - The push rod 5 with oil chamber and the oil return channels with the ball check valve, parts 8, 9 and 10. The ball valve separates the oil chamber from the working chamber; - The guide sleeve 6 to the working chamber b, the compression spring 9 and the closure cap 4. With the engine stopped, if the expansion is under constant pressure cam camshaft, it can be fully discharged (compressed). The oil extruded from the working chamber b, flows into the oil chamber and in the annular gap - the annulus between the guide sleeve and the push rod. When the top of the cam away with the rocker, the push rod 5 with the load is removed. Spring rod 9 moves upward as long as the rocker arm comes into contact with the cam. The vacuum created in the chamber by movement of the stem opens the ball valve, and oil can flow from the oil chamber into the working chamber. The ball valve closes as soon as the rocker rests against the cam, push rod on the load begins to increase. The oil in the chamber now operates as a rigid hydraulic connection, which opens the corresponding valve. When the engine is running, depending on the engine speed and the cam position, the push rod is lowered by a small amount. The oil required for expansion joints, supplied by an oil pipeline running along the cylinder head, and then in the transverse channel leading to the rocker bearing uprights. Further, from the bearing struts, oil is supplied to the rocker arm shaft, and from there via h at the yoke - the corresponding compensator. The supply of oil in the oil chamber through the splined washer 3. The amount of oil in the oil chamber and always enough to in any engine operating conditions to fill the working chamber b. Excess oil and air inclusions (air bubbles in the oil) may extend through the annular gap between the collar 3 and a yoke. The oil extruded from the working chamber flows along the annular slit (in the interspace) between the guide sleeve and the pressure rod and further along the return channel - in the oil chamber. When removing hydropushers should remember the following points: - Hydropushers should always be stored in an upright position - open side up. - After dismantling hydropusher (Sect. 2.13.2) should be mark with the number of cylinders, the well pusher.
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