Yuchai YC6A Series, Operation & Maintenance Manual

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and seized between camshaft timing gear and thrust plate. Fig 2-5 and Fig 2-4
过大则会引起凸轮轴窜动和气门正时不准，也容易造成供缸盖机油油孔的错位堵塞而上
不了油。进排气门摇臂各有
6
个，与气门杆端接触的头部有镶块，经氮碳共渗后，有很高的硬
度，耐磨性好。
If the clearance is too large, it will cause camshaft run out and incorrect valve timing and also
will lead the misplacement of oil supply valve head oil hole and can not supply the oil. There
are 6 rockers on each intake valve and exhaust valve, there is glut with valve lever on the
connected end. After nitro carburizing, it has high hardness and good wearing resistance.
摇臂轴为
3
缸
1
根，每根支撑在
3
个摇臂支座上。在检修后安装时应注意，从气缸盖的油
道用一油管接到中间的摇臂支座上，摇臂轴中心有一油道，通过该油道将润滑油送往另两个摇
臂支座供润滑用。拆装气门弹簧时，要使用专门的工具，见图
2—6
。
One rocker arm shaft is equipped for three valves and every shaft supports on the rocker arm
seat. When installing after checking, please pay attention that the oil path of valve head is
connected to the middle rocker arm seat, there is one oil path at the center of rocker arm
shaft, the lubricant is delivered to these two rocker arm seats for lubricating through this oil
path. When dismounting valve spring, the special tools shall be used. See Fig 2-6
3.2.4.2
正时齿轮及传动
Timing Gear and Belt Drive
凸轮轴的驱动是通过齿轮的驱动来实现。曲轴正时齿轮为主动齿轮，向上通过正时惰齿
轮传动喷油泵齿轮和凸轮轴正时齿轮，向下通过机油泵中间齿轮传动机油泵齿轮。曲轴正时
齿轮、正时惰齿轮、喷油泵齿轮及凸轮轴齿轮上均刻有正时记号，安装时须对准记号进行装
配，以免影响使用性能。齿轮侧向间隙要求为
0.07
～
0.30mm
（图
2—7
）（图
2—8
）
The camshaft is driven by the gear. The crankshaft timing gear is driving gear; it moves
upwards to drive fuel injection pump gear and camshaft timing gear through timing idler gear,
and it moves downwards to drive oil pump gear through oil pump middle gear. Timing marks
are printed on crankshaft timing gear, timing idler gear, fuel injection pump gear and camshaft
gear. Align to the mark when assembling to avoid incorrect installation influencing the
performance. The side gear clearance shall be 0.07
～
0.30mm (Fig 2-7) (Fig 2-8)