Adjustment of axial clearance of camshaft of biogas generator set. When the camshaft works, due to thermal expansion, a certain axial clearance needs to be left. However, if the clearance is too large, more than 2.5mm, it will cause the axial movement of camshaft and aggravate the wear of parts. Moreover, due to the change of camshaft position, it will cause the change of gas distribution phase and affect the normal operation of Shandong biogas generator set. Therefore, the camshaft should be positioned axially.

發電機工作時，由于零件的磨損與松動，或者正時齒輪室蓋經過拆裝后，均需調整凸輪軸的向間隙，以保證凸輪軸正常工作。發電機凸輪軸的軸向定位，是用齒輪室蓋上的止推螺釘實現的。調整時，需將止推累釘擰到底，消除軸向間隙，然后再退回約1/4圈即可。

When the generator is working, due to wear and looseness of parts, or after disassembly and assembly of timing gear chamber cover, the axial clearance of camshaft shall be adjusted to ensure normal operation of camshaft. The axial positioning of the generator camshaft is realized by the thrust screw on the gear chamber cover. During adjustment, screw the thrust accumulation pin to the end to eliminate the axial clearance, and then return it for about 1 / 4 turn.

不能將發電機曲軸箱的通氣孔堵死。發電機工作過程中，每當活塞下行時，曲軸箱內的氣體（包括泄漏來的燃氣）受壓縮，使箱內氣體壓力升高，造成油底殼結合面處機油向外滲漏，并對活塞運動產生阻力。因此，發電機曲軸箱應有通大氣的通氣孔。

The vent hole of the generator crankcase must not be blocked. During the operation of the generator, whenever the piston goes down, the gas in the crankcase (including the leaked gas) is compressed, which increases the gas pressure in the crankcase, resulting in the outward leakage of oil at the joint surface of the oil pan and resistance to the movement of the piston. Therefore, the crankcase of the generator shall have an air vent to the atmosphere.

不同型號的發電機，曲軸箱上通氣孔的位置不一樣，但其工作原理相同，即單向閥作用原理。當活塞由止點向下止點移動時，曲軸箱氣壓增高將閥打開，使氣體排出；當活塞由下止點向上止點移動時，曲軸箱氣壓隨著空間變大而降為負壓。

Different types of generators have different positions of vent holes on the crankcase, but their working principle is the same, that is, the action principle of one-way valve. When the piston moves from dead center to dead center, the crankcase air pressure increases and the valve opens to exhaust the gas; When the piston moves from BDC to TDC, the crankcase air pressure decreases to negative pressure as the space becomes larger.

負壓使閥堵住曲軸箱與外界的通道，阻止外界的灰塵進入曲軸箱，保持潤滑油的清潔，并使發電機工作時潤滑油向外滲泄的機會減少。因此，發電機曲軸箱的通氣孔應保持暢通，保證曲軸箱對外呼氣。

The negative pressure makes the valve block the passage between the crankcase and the outside world, prevent the outside dust from entering the crankcase, keep the lubricating oil clean, and reduce the chance of lubricating oil leakage when the generator is working. Therefore, the vent hole of the generator crankcase should be kept unblocked to ensure that the crankcase exhales.