低速重载齿轮齿条传动机构混合弹流润滑分析

Analysis of Mixed Elastohydrodynamic Lubrication Based on Low Speed Heavy Duty Rack and Pinion Transmission Mechanism

低速重载齿轮齿条传动机构广泛应用于矿山、水利等升降系统中,但由于其工况恶劣,极易发生磨损、胶合。以三峡升船机的大模数齿轮齿条传动机构为研究对象,建立瞬态混合弹流润滑模型,分析了其啮合过程中的润滑状态,并研究转速、齿面线接触载荷以及齿面粗糙度对润滑状态的影响。结果表明:在一个啮合周期中,啮入点是低速重载齿轮齿条在啮合过程中的危险点;在低速、重载工况下,齿面线接触载荷对啮入点润滑状态几乎不产生影响,而齿轮转速与齿面粗糙度对啮入点膜厚比的影响显著;另外,粗糙度纹理方向也会影响齿面润滑状态,其中横向粗糙度纹理能够使齿面具备较大的膜厚比,改善其润滑状态。

The rack and pinion transmission mechanism under condition of low-speed and heavy-duty is widely used in lifting systems such as mines and water conservancy. However,due to its poor working conditions,the tooth face is easy to be worn or welded. In this paper,the large-modulus rack-and-pinion transmission mechanism adopted by the Three Gorges ship-lift is taken as the research object,and the transient hybrid elastohydrodynamic lubrication model has been developed to analysis the lubrication state of the rack and pinion during a meshing process. And the effects of rotational speed,tooth surface contact load and tooth surface roughness on the lubrication state of large modulus gear racks operating under low speed and heavy load conditions were studied. The results show that in one meshing cycle,the biting point is the dangerous point of the low-speed,heavy-duty rack and pinion during the meshing process. Under low-speed and heavy-load conditions,the tooth surface line contact load hardly produces the lubrication state of the biting point. However,the influence of the gear speed and the tooth surface roughness on the film thickness ratio is significant. In addition,the roughness texture direction also affects the tooth surface lubrication state,wherein the transverse roughness texture can make the tooth surface have a larger film thickness ratio and improve its lubrication state.