【摘要】：金屬片與帶輪之間的潤滑油膜同時承載著動力傳遞與潤滑的任務(wù),是金屬帶式CVT(Continuously Variable Transmission)動力傳遞鏈中最為關(guān)鍵的環(huán)節(jié)。油膜特性直接決定變速器的潤滑效果和傳動效率,但在實際工況下油膜參數(shù)無法直接測量,難以對其進(jìn)行精確控制。針對此問題,本文基于熱彈流潤滑理論構(gòu)建了求解潤滑油膜特性參數(shù)的數(shù)學(xué)模型,采用數(shù)值模擬方法,分析了金屬帶滑移率、傳遞轉(zhuǎn)矩、傳動速比等工作參數(shù)對油膜特性的影響規(guī)律,為金屬帶式CVT的設(shè)計及發(fā)展基于油膜特性參數(shù)的控制方法提供參考。論文主要進(jìn)行了以下工作:(1)對無級變速機(jī)構(gòu)及其動力傳遞過程進(jìn)行了理論性分析。研究了傳動過程中金屬帶各類滑動摩擦形成的機(jī)理,分析了金屬帶滑移對變速器傳動效率的影響。對滑移狀態(tài)下金屬帶與帶輪之間潤滑油膜形成機(jī)理進(jìn)行了分析,發(fā)現(xiàn)潤滑油膜處于彈流潤滑狀態(tài),且溫度對油膜有較大影響。(2)基于熱彈流潤滑的相關(guān)理論,建立了適合本研究的油膜數(shù)學(xué)模型。根據(jù)變速機(jī)構(gòu)結(jié)構(gòu)參數(shù)推導(dǎo)了傳遞轉(zhuǎn)矩、速比、滑移率與模型中相對速度、載荷及綜合曲率半徑之間的關(guān)系,并根據(jù)實際工況確定了方程的邊界條件。分析了模型中各方程的特點,確定了求解流程,并進(jìn)行了求解。(3)通過數(shù)值模擬得到了油膜壓力、油膜厚度及油膜溫度的分布情況。借助數(shù)值仿真研究了各工作參數(shù)對油膜對稱面上壓力、溫升、膜厚影響規(guī)律。設(shè)計了考慮交互作用的正交試驗,得到了最大壓力、最小膜厚、最大溫升對各工作參數(shù)的敏感度。(4)設(shè)計了油膜溫度試驗,獲取了油膜在各工作參數(shù)不同水平下的溫度。試驗結(jié)果顯示試驗所測溫度值與仿真值之間存在一定差值,最大可達(dá)12℃,但是變化趨勢基本一致,仿真結(jié)果經(jīng)過修正后可以作為金屬帶式CVT的設(shè)計及發(fā)展基于油膜特性參數(shù)控制方法的參考依據(jù)。
[Abstract]:The lubricating oil film between the metal sheet and the belt wheel carries the task of power transfer and lubrication simultaneously, which is the most important link in the metal belt CVT (Continuously Variable Transmission) power transfer chain. The oil film characteristics directly determine the lubricating effect and transmission efficiency of the transmission, but the oil film parameters can not be measured directly under the actual working conditions, so it is difficult to control them accurately. In order to solve this problem, a mathematical model for solving the characteristic parameters of lubricating oil film is constructed based on the theory of thermo-elastohydrodynamic lubrication. The slip ratio and transfer torque of metal belt are analyzed by numerical simulation method. The influence of working parameters such as transmission speed ratio on oil film characteristics provides a reference for the design of metal belt type CVT and the development of control method based on oil film characteristic parameters. The main work of this paper is as follows: (1) theoretical analysis of continuously variable speed mechanism and its dynamic transfer process is carried out. The forming mechanism of sliding friction of metal belt in transmission process is studied, and the influence of metal belt slip on transmission efficiency is analyzed. The formation mechanism of lubricating oil film between metal strip and belt wheel is analyzed. It is found that lubricant film is in elastohydrodynamic state and temperature has great influence on oil film. (2) based on the theory of thermo-elastohydrodynamic lubrication, A mathematical model of oil film suitable for this study was established. According to the structural parameters of the variable speed mechanism, the relations between the transfer torque, speed ratio, slip ratio and relative velocity, load and comprehensive curvature radius in the model are derived, and the boundary conditions of the equation are determined according to the actual working conditions. The characteristics of each equation in the model are analyzed, and the solution flow is determined. (3) the distribution of oil film pressure, film thickness and oil film temperature is obtained by numerical simulation. The effects of working parameters on the pressure, temperature rise and film thickness on the symmetrical surface of oil film were studied by numerical simulation. The orthogonal test considering the interaction is designed, and the sensitivity of the maximum pressure, the minimum film thickness and the maximum temperature rise to the working parameters is obtained. (4) the oil film temperature test is designed, and the oil film temperature at different working parameters is obtained. The experimental results show that there is a certain difference between the measured temperature value and the simulation value, and the maximum value can reach 12 鈩，

本文編號：2413615