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.

发电机工作时，由于零件的磨损与松动，或者正时齿轮室盖经过拆装后，均需调整凸轮轴的向间隙，以保证凸轮轴正常工作。发电机凸轮轴的轴向定位，是用齿轮室盖上的止推螺钉实现的。调整时，需将止推累钉拧到底，消除轴向间隙，然后再退回约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.

不能将发电机曲轴箱的通气孔堵死。发电机工作过程中，每当活塞下行时，曲轴箱内的气体（包括泄漏来的燃气）受压缩，使箱内气体压力升高，造成油底壳结合面处机油向外渗漏，并对活塞运动产生阻力。因此，发电机曲轴箱应有通大气的通气孔。

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.

不同型号的发电机，曲轴箱上通气孔的位置不一样，但其工作原理相同，即单向阀作用原理。当活塞由止点向下止点移动时，曲轴箱气压增高将阀打开，使气体排出；当活塞由下止点向上止点移动时，曲轴箱气压随着空间变大而降为负压。

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.

负压使阀堵住曲轴箱与外界的通道，阻止外界的灰尘进入曲轴箱，保持润滑油的清洁，并使发电机工作时润滑油向外渗泄的机会减少。因此，发电机曲轴箱的通气孔应保持畅通，保证曲轴箱对外呼气。

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.