本文選題：硬齒面齒輪 + 剪切應力　； 參考：《機械科學研究總院》2016年博士論文

【摘要】：隨著科學技術的進步,齒輪傳動正逐漸向輕量化、低能耗方向發(fā)展。齒輪裝置是機械傳動系統(tǒng)的核心設備,隨著工業(yè)技術的迅速發(fā)展,對其承載能力和經濟性提出了更高的要求。由于硬齒面齒輪具有強度高、體積小、質量輕等一系列優(yōu)點,目前硬齒面熱處理工藝已得到普遍使用。但是,熱處理工藝過程中的節(jié)能降耗卻是對齒輪熱處理生產的重要考驗。節(jié)能是熱處理技術發(fā)展中的一項意義重大但又艱巨的任務,節(jié)能工藝的推廣應用,在齒輪行業(yè)具有重要的意義。采用硬齒面齒輪替代軟齒面或中硬齒面齒輪,是齒輪輕量化的重要手段。然而,齒面剝落作為硬齒面齒輪主要的失效形式嚴重制約了齒輪承載能力的大幅度提高。齒輪剝落失效的產生不僅與齒面下的剪應力分布有關,而且與硬化層的深度、硬化層的硬度梯度等因素有關。表面硬化齒輪的有效硬化層深度與齒輪的強度、可靠性等性能密切相關,是保證齒輪承載能力充分發(fā)揮的關鍵。增加硬化層的深度有利于齒輪承載能力的提高,防止疲勞剝落失效。然而,過大的硬化層深度又會帶來如工藝難度加大、工藝周期增長、畸變增加等諸多問題,造成齒輪生產成本和能源消耗的增加。合理硬化層深度設計的要點是既要保證過渡區(qū)有足夠的強度防止深層剝落,又不過分加大安全余度。設計最佳的齒輪硬化層深度,無論是對提高齒輪齒面承載能力和產品質量,還是節(jié)能降耗都是極其重要的。因此,進一步開展能夠防止齒輪疲勞剝落并節(jié)能的最佳硬化層深度研究已成為齒輪設計中的一項十分重要的工作。但目前為止,還沒有一種行之有效的硬化層深度設計方法可用于齒輪的抗剝落計算。本文從剝落產生的力學角度出發(fā),對齒輪疲勞剝落強度進行了研究及試驗驗證。論文主要研究內容有：(1)利用彈性力學理論,在不考慮摩擦因數(shù)和考慮摩擦因數(shù)的情況下,分別分析了齒面下兩種剪切應力的分布特點,以及不同摩擦因數(shù)條件下齒輪剪切應力的變化規(guī)律。為了更方便、直觀地了解齒面下剪切應力的分布,采用克里格插值方法得到了正交剪切應力和最大剪切應力的空間分布圖。利用有限元方法對齒輪接觸的剪切應力進行了計算,并與理論方法計算結果進行了對比分析。(2)討論了齒輪硬化層深度的力學意義,分析了齒輪曲率半徑、心部硬度、殘余應力及齒面加工質量等與齒輪硬化層剝落的關系。根據(jù)最大剪切應力和判據(jù),提出了一種抗齒面剝落的硬化層深度設計方法,并根據(jù)剪切應力與剪切強度的關系,得到了齒輪最低要求的硬度分布曲線。在此基礎上提出了定量確定齒輪最小有效硬化層深度的計算方法。(3)根據(jù)齒輪有效硬化層深設計方法,推導了計算齒輪齒面下最大剪切應力和齒輪有效硬化層深的公式,為定量確定齒輪有效硬化層深度提供了一種簡便可行的方法�；邶X輪有效硬化層深度的計算公式,得到了齒輪有效硬化層分布模型,實現(xiàn)了對齒輪有效硬化層深的定量分析。通過對齒輪硬化層深的影響因素進行分析研究,找出了齒輪參數(shù)中對硬化層深度影響最大的因素。(4)考慮到不同硬化層深度對齒輪接觸疲勞強度的影響,把安全系數(shù)和可靠性計算與硬化層深度聯(lián)系起來,建立了考慮硬化層深度影響的齒輪安全系數(shù)和可靠度計算模型,得到了不同硬化層深度與安全系數(shù)和可靠度的對應關系,使齒輪硬化層深度的選取更加直觀、更加科學。(5)利用齒輪抗剝落硬化層深度設計方法對試驗齒輪疲勞剝落強度進行了計算,根據(jù)齒面下的應力與強度的分布規(guī)律對齒輪是否發(fā)生剝落失效及齒面下疲勞裂紋萌生的位置進行了預測,并通過齒輪接觸疲勞試驗進行了驗證。分別從材料的化學成分、夾雜物的檢測、金相組織分析、應力分析、硬化層深度分析、偏載、過載分析等方面對齒輪剝落失效產生的原因進行了分析。(6)結合熱處理工藝試驗,利用力學判據(jù)對風電齒輪箱中齒圈以及三峽升船機齒條硬化層的疲勞剝落強度進行了分析,通過對比分析齒輪所需硬度與實際熱處理硬度沿深度方向的分布特點,對目前風電齒輪和升船機齒輪所采用的硬化層深度進行了評估和驗證。
[Abstract]:With the progress of science and technology, the gear transmission is gradually developing to light weight and low energy consumption. The gear device is the core equipment of the mechanical transmission system. With the rapid development of industrial technology, the bearing capacity and economy of the gear are higher. The hard tooth gear has a series of advantages, such as high strength, small volume, and light quality. At present, the heat treatment process of hard tooth surface has been widely used. However, energy saving and consumption reduction in heat treatment process is an important test for the production of gear heat treatment. Energy saving is a significant but arduous task in the development of heat treatment technology. The popularization and application of energy saving technology is of great significance in the gear industry. Face gear instead of soft tooth or medium hard tooth gear is an important means of gear light weight. However, the main failure mode of the tooth surface exfoliation as the main failure form of the hard tooth gear restricts the large increase of the bearing capacity of the gear. The production of the spalling failure of the gear is not only related to the shear stress distribution under the tooth surface, but also with the depth of the hardened layer. The depth of the effective hardening layer of the surface hardening gear is closely related to the strength and reliability of the gear. It is the key to ensure the full play of the gear carrying capacity. The depth of the hardened layer is beneficial to the improvement of the gear bearing capacity and the fatigue failure. However, the depth of the oversize hardened layer will be the same. There are many problems such as increasing process difficulty, increasing process cycle, increasing distortion and so on, resulting in the increase of gear production cost and energy consumption. The main point of the design of reasonable hardened layer depth is not only to ensure that the transition zone has enough strength to prevent deep exfoliation, but also not to increase the safety redundancy too much. It is very important to improve the bearing capacity and product quality of gear teeth and the energy saving and reducing consumption. Therefore, it has become a very important work in gear design to further study the optimum depth of hardened layer which can prevent the gear fatigue and energy saving. But so far, there is no effective depth of hardened layer. The method can be used to calculate the anti peeling of gear. From the mechanical angle of exfoliation, the fatigue strength of gear is studied and tested. The main contents of this paper are as follows: (1) using the theory of elastic mechanics, two shear stresses under the tooth surface are analyzed without considering the friction factor and the friction factor. The distribution of the shear stress of the gear under the conditions of different friction factors and the distribution of the shear stress under the tooth surface can be easily understood. The spatial distribution of the orthogonal shear stress and the maximum shear stress is obtained by Kriging interpolation. The shear stress of the gear contact is carried out by the finite element method. The calculation is compared with the calculation results of the theoretical method. (2) the mechanical significance of the depth of the gear hardening layer is discussed. The relationship between the curvature radius of the gear, the hardness of the heart, the residual stress and the machining quality of the tooth surface is analyzed. The hardening layer of the tooth surface exfoliation is put forward according to the maximum shear stress and criterion. On the basis of the relationship between shear stress and shear strength, the minimum required hardness distribution curve of gear is obtained. On this basis, a calculation method for determining the minimum effective hardening layer depth of gear is put forward. (3) the maximum shear stress and tooth under the gear surface are calculated according to the design method of the effective hardening layer of gear. The formula to effectively harden the depth of the layer provides a simple and feasible method for quantitative determination of the depth of the effective hardening layer of a gear. Based on the calculation formula of the depth of the effective hardening layer of the gear, the distribution model of the effective hardening layer of the gear is obtained, and the quantitative analysis of the depth of the effective hardening layer of the gear is realized. In line analysis, the factors that have the greatest influence on the depth of the hardened layer are found. (4) considering the influence of the depth of different hardened layer on the contact fatigue strength of gear, the calculation of safety factor and reliability and the depth of the hardened layer are linked, and the calculation model of gear safety factor and reliability considering the influence of hardened layer depth is established. The corresponding relationship between the depth of different hardening layers and the safety factor and reliability makes the selection of the depth of the gear hardened layer more intuitive and more scientific. (5) the calculation of the fatigue exfoliation strength of the test gear is carried out by the method of the depth design of the gear resistance to the exfoliation hardening layer, and the distribution of the stress and strength under the tooth surface will occur to the gear. The position of the exfoliation failure and the initiation of the fatigue crack under the tooth surface was predicted and verified by the gear contact fatigue test. The reasons for the spalling failure of the gear were analyzed from the aspects of the chemical composition of the material, the inclusion, the metallographic analysis, the stress analysis, the depth analysis of the hardened layer, the partial load, and the overload analysis. (6) combined with the heat treatment process test, the fatigue exfoliation strength of the gear box in the wind electric gear box and the rack hardening layer of the Three Gorges ship lifting machine is analyzed by the mechanical criterion. By comparing and analyzing the characteristics of the hardness of the gear and the distribution characteristic of the actual heat treatment hardness along the depth direction, the hardening of the current wind power gear and the ship lift gear is hardened. The depth of the layer is evaluated and verified.
【學位授予單位】：機械科學研究總院
【學位級別】：博士
【學位授予年份】：2016
【分類號】：TH132.41

【相似文獻】

相關期刊論文 前10條

1 程國明;鄭耘;;對齒輪材料的研究[J];消費導刊;2010年08期

2 М.П.НОВИКОВ ,程┌，

本文編號：1993386