High performance motorcycle engine powder metallurgy gear cam and manufacturing method thereof

Abstract

The invention discloses a high performance motorcycle engine powder metallurgy gear cam. The high performance motorcycle engine powder metallurgy gear cam comprising a body made by powder metallurgy for entire structure comprises a bearing journal, a shaft gear, a drive gear mounting journal and drive gears which are located in the same axle and which are arrayed sequentially. The tooth roots of adjacent drive gears are in fillet transition. The outer wall of the bearing journal, the outer wall of the shift gear, the outer wall of the drive gear mounting journal and the outer walls of the drive gears are provided with wear resistant composite layers. According to a preferable technical scheme, the wear resistant composite layers are rare earth compound composite layers. The invention further discloses a manufacturing method of the high performance motorcycle engine powder metallurgy gear cam. The method includes blending, mixing, pressing, sintering, heating, hot forging, finishing and chemical infiltrating procedures. Material utilization rate is high, strength, fatigue resistance and other mechanical properties of the motorcycle engine gear cam can be guaranteed, wear resistance can be guaranteed, and the problem of stress concentration of the tooth roots of the drive gears can be solved.

Description

Technical field [0001] The invention relates to a shift cam and a manufacturing method thereof, more specifically, the present invention relates to a powder metallurgy shift cam for a motorcycle engine manufactured by a powder metallurgy method and a manufacturing method thereof. Background technique [0002] Motorcycle engine shift cams are used for motorcycle shifting. Nowadays, the drive gear and shift cam are generally assembled together, and the shift cam is driven by the drive gear to achieve shifting. Motorcycle engine shift cams must ensure certain strength and fatigue resistance, and at the same time, the relatively moving surfaces such as the drive gear teeth and the cam outer wall of the shift cam should also have better wear resistance. In actual use, the prior art motorcycle engine shift cam has the following defects: the drive gear and shift cam are generally made of medium carbon steel or alloy steel, which are processed and heat-treated. The processing volume of p...

AI Technical Summary

Problems solved by technology

In actual use, the motorcycle engine shift cam of the prior art has the following defects: the driving gear and the shift cam are generally medium carbon steel or alloy steel, which are processed and heat-treated, and the parts are processed in a large amount, and the waste of materials is relatively large. Many; in order to ensure the strength, fatigue resistance and wear resistance of the motorcycle engine shift cam, the prior art adopts a heat treatment process, and the drive gear and the shift cam are heat-treated to achieve higher hardness, but the higher hardness The internal stress of the drive gear and the gear shift cam is relatively large, especially the drive gear, the roots of adjacent teeth are connected by planes, and the intersection of the tooth side and the plane of the tooth root is a sharp angle or a small transition Rounded corners are prone to stress concentration. If the hardness of the gear tooth after treatment is high, a large stress concentration will occur at the root of the gear tooth, which will easily lead to fracture failure of the drive gear tooth; Hardness is used to reduce the stress concentration at the root of the drive gear, which will cause the teeth of the drive gear to be wear-resistant, and the service life of the shift cam of the motorcycle engine will be short

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