我场一台东方红—75拖拉机在工作时,低、中速运转正常,高速时排气管出现“砰、砰”的响声,同时间断冒白烟。拧松四缸高压油管螺母切断供油后,异常响声及白烟消失。故障在哪? 打开检视窗,检查四缸的柱塞弹簧、柱塞挺杆的调整螺钉、凸轮等无异常。最后撬动凸轮轴,发现径向间隙较大,是后轴承滚道剥落,更换后故障排除。 I field a red-75 tractor at work, low, medium-speed normal operation, high-speed exhaust pipe when there “bang, bang” sound, at the same time take the white smoke. Loose four-cylinder high-pressure tubing nut cut off the oil, abnormal noise and white smoke disappear. Where is the fault? Open the inspection window, check the four-cylinder plunger spring, plunger tappet adjustment screw, cam and so on without exception. Finally leveraging camshaft and found that the larger radial clearance is after the bearing roller flaking, replacement troubleshooting.