Timing drive mechanism for motorcycle engine

Abstract

The invention discloses a timing drive mechanism for a motorcycle engine, which comprises a timing chain and a tensioning device. The tensioning device comprises a tensioning plate and a tensioner; one side of the tensioning plate is in a convex arc shape and is attached to the timing chain, and the other side of the tensioning plate is provided with a convex bag; the tensioner is fixed on a cylinder body and is provided with a tensioning rod; and one end of the tensioning rod is arranged in the tensioner, and the other end of the tensioning rod stretches out under the action of a spring and is opposite to the convex bag. The improvement is that: the bottom of a groove is provided with a smooth plane; the coordination distance between the timing chain and the side wall of the groove is less than 0.1mm; the convex bag is provided with a limiting hole; one end of the tensioning rod opposite to the convex bag is positioned in the limiting hole and is in interference fit with the limitinghole; and a limiting plate is arranged below a crankshaft sprocket. The timing drive mechanism has the advantages of small vibration, low noise, long service life, convenience of maintenance and the like.

Description

technical field [0001] The invention relates to the field of motorcycle engines, in particular to a timing transmission mechanism of a motorcycle engine. Background technique [0002] The timing transmission mechanism of motorcycle engine is a transmission mechanism used between the crankshaft of motorcycle engine and the valve camshaft, including timing chain and tensioning device. The timing chain generally adopts roller chain, and its main function is It transmits the power of the engine crankshaft to the valve camshaft, and then drives the opening and closing of the intake and exhaust valves to realize the intake, exhaust, compression and work of the engine; since the length of the timing chain is an integer multiple of the fixed pitch, Generally, they are longer than the actual needs, so the chain drive needs to be designed with a tensioning device, which is used to tension the timing chain. [0003] The most common existing motorcycle engine timing transmission mechan...

AI Technical Summary

Problems solved by technology

Eventually, the wear of the timing chain and the tension plate will increase, the abnormal noise of the engine will increase, and the life of the parts will be shortened.

[0006] The second defect is that when inspecting and maintaining the engine, it is often necessary to inspect and maintain the gas turbine part. When inspecting and maintaining the gas turbine part, it is not necessary to open the crankcase, just remove the cylinder head.

When the maintenance is completed and reinstalled, the timing chain needs to be put on the crankshaft sprocket again. However, since the crankshaft sprocket is located in the crankcase and cannot be seen, it is difficult to put it on. At this time, the crankcase also needs to be disassembled (originally No need), all the parts around the crankshaft sprocket can be removed, and then the timing chain can be put on, and then reinstalled, which is time-consuming and laborious, so this kind of tensioning device is extremely inconvenient for the maintenance of the gas turbine part

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