The camshaft is a component in a piston engine.Its function is to control the opening and closing of the valve.Although in the four-stroke engine camshaft speed is half of the crankshaft (in two stroke engine camshaft speed is the same as the crankshaft), but usually it's speed is still high, but need to bear large torque, so the design of a high requirement on the camshaft in terms of strength and support, the material is high quality alloy steel or alloy steel.Because the law of valve movement is related to the dynamic and running characteristics of an engine, camshaft design occupies a very important position in the process of engine design.
Common faults of camshaft include abnormal wear, abnormal sound and fracture, which are usually preceded by symptoms of abnormal wear.
(1) The camshaft is almost at the end of the engine lubrication system, so the lubrication situation is not optimistic.Abnormal wear of the camshaft will occur if the oil supply pressure is insufficient due to the long service time of the oil pump, the lubricating oil cannot reach the camshaft due to the blockage of the lubricating oil channel, or the lubricating oil cannot enter the camshaft clearance due to the excessive tightening torque of the bearing cap fastening bolt.
(2) The abnormal wear of the camshaft will lead to the increase of the clearance between the camshaft and the bearing seat, and the axial displacement will occur when the camshaft moves, thus producing abnormal sound.Abnormal wear will also lead to the increase of the gap between the driving CAM and hydraulic tappet, CAM and hydraulic tappet when combined will collide, resulting in abnormal sound.
(3) Sometimes the camshaft fracture and other serious faults, common reasons are hydraulic tappet fracture or serious wear, serious poor lubrication, camshaft quality and camshaft timing gear fracture, etc.
(4) In some cases, the camshaft failure is caused by human causes, especially when the camshaft is not properly disassembled and installed during engine maintenance.For example, when removing the camshaft bearing cover, hammer is used to forcefully strike or screwdriver is used to pry pressure; or when installing the bearing cover, the wrong position is installed, resulting in the mismatching between the bearing cover and the bearing seat; or the tightening torque of the bearing cover fastening bolt is too large.When installing the bearing cover, it is necessary to pay attention to the mark of direction arrow and position number on the surface of the bearing cover, and tighten the fastening bolt of the bearing cover with torque wrench in strict accordance with the prescribed torque.Wholesale Engine System





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