林騰蛟 趙子瑞 江飛洋 陳兵奎
摘? ?要:以斜齒輪副為研究對象,基于切片法和積分思想,計入齒面接觸溫度變化引起的齒廓形變,結(jié)合輪齒接觸、彎曲、剪切、軸向壓縮及基體彈性變形,提出了考慮溫度效應的斜齒輪嚙合剛度解析算法,并通過有限元法驗證了算法的準確性. 分析了不同摩擦因數(shù)、輸入轉(zhuǎn)矩、輸入轉(zhuǎn)速等工況參數(shù)對斜齒輪嚙合剛度的影響規(guī)律. 結(jié)果表明,考慮齒輪溫升影響后,輪齒從嚙入到嚙出整個過程的嚙合剛度均有所增大;隨著摩擦因數(shù)、輸入轉(zhuǎn)矩和輸入轉(zhuǎn)速的增大,斜齒輪本體溫度及嚙合齒面瞬時閃溫升高,單齒嚙合剛度和綜合嚙合剛度均值呈增大趨勢. 研究結(jié)果可為高速重載齒輪系統(tǒng)準確高效的動力學分析提供理論依據(jù).
關(guān)鍵詞:斜齒輪;溫度效應;時變嚙合剛度;勢能法
中圖分類號:TH132.41 ? ? ? ? ? ? ? ? ?文獻標志碼:A
Abstract:Taking a helical gear pair as the research object,the analytic algorithm of time-varying mesh stiffness of helical gears with temperature was proposed based on slicing method and integral thought. In this algorithm,the tooth profile deformation caused by change of tooth contact temperature,elastic deformation of tooth contact,bending,shear,axial compression and the wheel were taken into account. The accuracy of the algorithm was verified by using finite element method. Then the influence of working parameters,such as friction coefficient,input torque and input speed,on the mesh stiffness of gears was analyzed. The results show that the mesh stiffness of teeth increases in the whole meshing process after considering the influence of temperature. Besides,the body temperature and instantaneous flash temperature of helical gears increase with the increase of friction coefficient,input torque and input speed,so the single mesh stiffness and the mean of total mesh stiffness increase. The research results can provide a theoretical basis for accurate and efficient dynamic analysis of the high-speed and heavy-duty gear system.
Key words:helical gears;temperature effect;time-varing mesh stiffness;potential energy method
齒輪系統(tǒng)作為機械裝置中最為廣泛的動力和運動傳遞形式,正朝著大功率、高轉(zhuǎn)速、低噪聲和輕量化方向發(fā)展. 在高速重載工況下,由于嚙合齒面相對滑動速度大,瞬時溫升高,直接影響齒輪系統(tǒng)內(nèi)部的溫度分布,引起結(jié)構(gòu)熱應力及熱變形,進而對齒輪嚙合剛度產(chǎn)生較大影響,而準確高效的嚙合剛度計算方法又是齒輪系統(tǒng)動力學分析的關(guān)鍵. 因此,綜合考慮溫度影響,開展斜齒輪時變嚙合剛度解析算法研究,對高速重載齒輪系統(tǒng)動力學設計有著重要的工程意義.
近年來,對于齒輪系統(tǒng)時變嚙合剛度的研究非?;钴S. 在解析算法方面,Cui等[1]、Chaari等[2]和
Liang等[3]基于材料力學理論,運用勢能法計算了直齒輪的嚙合剛度;在直齒輪嚙合剛度算法的基礎上,Wan等[4]提出了一種累積積分勢能法計算斜齒輪的嚙合剛度,并研究了齒輪參數(shù)與齒根裂紋對嚙合剛度的影響;萬志國等[5]、劉文等[6]考慮了基圓與齒根圓不重合的問題,運用勢能法分別提出了求解直齒輪及斜齒輪嚙合剛度的改進算法. 在有限元法方面,Cooley等[7]、Liang等[8]提出了多種基于有限元法的直齒輪時變嚙合剛度計算方法,并評估了各種方法的應用條件及優(yōu)缺點;Fernandez等[9-10]和Ma等[11]綜合考慮加工誤差、齒頂修形或齒輪摩擦等非線性因素,采用有限元法與彈性接觸理論相結(jié)合的方式,計算了直齒輪的時變嚙合剛度. 在考慮溫度效應方面,茍向鋒等[12]建立了由齒面接觸溫度變化引起直齒輪齒廓形變的數(shù)學表征,而后基于Hertz接觸理論研究了接觸溫度對直齒輪嚙合剛度的影響;羅彪等[13]基于石川模型,將輪齒齒廓簡化為由梯形和矩形組成的當量齒形,綜合考慮溫度對直齒輪剛度的影響,引入了熱剛度的概念,并提出了一種直齒輪熱剛度的解析算法,計算結(jié)果與有限元法基本吻合. 目前有關(guān)考慮溫度效應的齒輪嚙合剛度研究已取得一定的成果,但有限元法計算規(guī)模較大,解析法僅針對直齒輪開展了相關(guān)研究,關(guān)于考慮溫度效應的斜齒輪時變嚙合剛度解析算法鮮有報道.
在上述研究成果的基礎上,本文以斜齒輪副為研究對象,提出一種考慮溫度效應的斜齒輪嚙合剛度解析算法. 將輪齒簡化為齒根圓上的變截面懸臂梁,基于切片法和積分思想,在考慮基圓與齒根圓不重合因素的同時,計入齒面接觸溫度變化引起的輪齒齒廓形變,以確保嚙合剛度計算結(jié)果準確性;而后分析摩擦因數(shù)、輸入轉(zhuǎn)矩、輸入轉(zhuǎn)速等工況參數(shù)對斜齒輪嚙合剛度的影響規(guī)律.
1? ?考慮熱變形的斜齒輪端面齒廓方程
1.1? ?斜齒輪基體熱變形
斜齒輪副達到熱平衡狀態(tài)后,本體溫度場基本穩(wěn)定,但各處溫度非均一. 對于齒輪基體,盡管本體溫度場穩(wěn)定,但與輪齒相固聯(lián)的基體部分溫度不同,因此將斜齒輪基體溫度場處理為無內(nèi)熱源穩(wěn)態(tài)非均勻溫度場,其在柱面坐標系下的導熱微分方程為[14]:
5? ?結(jié)? ?論
1)將輪齒簡化為齒根圓上的變截面懸臂梁,計
入齒面接觸溫度變化引起的輪齒齒廓形變,基于勢能法提出了一種考慮溫度效應的斜齒輪嚙合剛度解析算法,通過與有限元法計算結(jié)果對比分析,驗證了解析算法的準確性,提升了斜齒輪嚙合剛度的計算效率.
2)考慮斜齒輪溫升影響后,輪齒從嚙入到嚙出整個過程的嚙合剛度均有所增大. 對于單齒嚙合剛度,在嚙入和嚙出端增大量較小,在節(jié)點附近增大量較大.
3)通過不同摩擦因數(shù)、輸入轉(zhuǎn)矩、輸入轉(zhuǎn)速等工況參數(shù)對斜齒輪嚙合剛度的影響分析,得出考慮溫度效應后單齒嚙合剛度及綜合嚙合剛度均值均隨上述工況參數(shù)的增大而增大,其中輸入轉(zhuǎn)矩對嚙合剛度的影響最大.
參考文獻
[1]? ?CUI L L,ZHAI H,ZHANG F B. Research on the meshing stiffness and vibration response of cracked gears based on the universal equation of gear profile[J]. Mechanism and Machine Theory,2015,94:80—95.
[2]? ?CHAARI F,F(xiàn)AKHFAKH T,HADDAR M. Analytical modelling of spur gear tooth crack and influence on gear mesh stiffness[J]. European Journal of Mechanics- A/Solids,2009,28(3):461—468.
[3]? ? LIANG X H,ZUO M J,PANDEY M. Analytically evaluating the influence of crack on the mesh stiffness of a planetary gear set[J]. Mechanism and Machine Theory,2014,76:20—38.
[4]? ? WAN Z G,CAO H R,ZI Y Y,et al. Mesh stiffness calculation using an accumulated integral potential energy method and dynamic analysis of helical gears[J]. Mechanism and Machine Theory,2015,92:447—463.
[5]? ? 萬志國,訾艷陽,曹宏瑞,等. 時變嚙合剛度算法修正與齒根裂紋動力學建模[J]. 機械工程學報,2013,49(11):153—160.
WAN Z G,ZI Y Y,CAO H R,et al. Time-varying mesh stiffness algorithm correction and tooth crack dynamic modeling[J]. Journal of Mechanical Engineering,2013,49(11):153—160. (In Chinese)
[6]? ? 劉文,李銳,張晉紅,等. 斜齒輪時變嚙合剛度算法修正及影響因素研究[J]. 湖南大學學報(自然科學版),2018,45(2):1—10.
LIU W,LI R,ZHANG J H,et al. Study on correction algorithm of time-varying mesh stiffness of helical gears and its influencing factors [J]. Journal of Hunan University(Natural Sciences),2018,45(2):1—10. (In Chinese)
[7]? ? COOLEY C G,LIU C G,DAI X,et al. Gear tooth mesh stiffness:A comparison of calculation approaches[J]. Mechanism and Machine Theory,2016,105:540—553.
[8]? ? LIANG X H,ZHANG H S,ZUO M J,et al. Three new models for evaluation of standard involute spur gear mesh stiffness [J]. Mechanical Systems and Signal Processing,2018,101:424—434.
[9]? ? FERN?NDEZ A,VIADERO F,IGLESIAS M,et al. A model for the study of meshing stiffness in spur gear transmissions[J]. Mechanism and Machine Theory,2013,61:30—58.
[10] FERN?NDEZ A,IGLESIAS M,DE-JUAN A,et al. Gear transmission dynamic:effects of tooth profile deviations and support flexibility[J]. Applied Acoustics,2014,77(3):138—149.
[11]? MA H,ZENG J,F(xiàn)ENG R J,et al. An improved analytical method for mesh stiffness calculation of spur gears with tip relief[J]. Mechanism and Machine Theory,2016,98:64—80.
[12]? 茍向鋒,祁常君,陳代林. 考慮齒面接觸溫度的齒輪系統(tǒng)非線性動力學建模及分析[J]. 機械工程學報,2015,51(11):71—77.
GOU X F,QI C J,CHEN D L. Nonlinear dynamic modelling and analysis of gear system with tooth contact temperature[J]. Journal of Mechanical Engineering,2015,51(11):71—77. (In Chinese)
[13]? 羅彪,李威,李林升. 基于熱彈耦合的齒輪熱剛度研究[J]. 中南大學學報(自然科學版),2017,48(12):3209—3215.
LUO B,LI W,LI L S. Research on thermal stiffness of gear based on thermo-elastic coupling[J]. Journal of Central South University(Science and Technology),2017,48(12):3209—3215. (In Chinese)
[14]? 李桂華. 復雜規(guī)則曲面機械零件的熱變形理論及應用研究[D]. 合肥:合肥工業(yè)大學機械工程學院,2006:54—70.
LI G H. Theoretical and applied research of thermal deformation of complicated components with regular camber[D]. Hefei:College of Mechanical Engineering,Hefei University of Technology,2006:54—70. (In Chinese)
[15]? 李潤方. 齒輪傳動的剛度分析和修形方法[M]. 重慶:重慶大學出版社,1998:128—133.
LI R F. Stiffness analysis and modification method of gear transmission[D]. Chongqing:Chongqing University Press,1998:128—133. (In Chinese)