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Optimizing Multi-Row Cam Roller Bearing for Long Fatigue Life of Hydraulic Motors
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作者 Yu Fang Qi Su +4 位作者 Pengpeng Dong Yu Yang Bing Xu Chao Zhang Junhui Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第5期180-190,共11页
Cam-lobe radial-piston hydraulic motors are widely used as rotation driving units for various marine machinery owing to their ultrahigh output torque(more than 100 kN m).A multi-row cam roller bearing(MCRB)is the key ... Cam-lobe radial-piston hydraulic motors are widely used as rotation driving units for various marine machinery owing to their ultrahigh output torque(more than 100 kN m).A multi-row cam roller bearing(MCRB)is the key component that directly determines the fatigue life of a cam-lobe radial-piston hydraulic motor.However,compact geometry and complex loads render MCRB susceptible to fatigue failure,highlighting the need for an optimized MCRB to achieve longer fatigue life and higher reliability.Therefore,this study proposes an innovative geometry optimization method for an MCRB to improve its fatigue life.In this method,a quasi-static model was developed to calculate the load distribution,with the fatigue life of the MCRB calculated using both basic dynamic loading and load distribution.Subsequently,a genetic algorithm was used to obtain the optimized geometry parameters,which significantly improved the fatigue life of the MCRB.Finally,a loading test was conducted on a hydraulic motor installed with both the initial and optimized MCRB to validate the effectiveness of the proposed optimization method.This study provides a theoretical guideline for optimizing the design of MCRB,thereby increasing the fatigue life of hydraulic motors. 展开更多
关键词 Hydraulic motor Cam roller bearing Fatigue life Geometry optimization Load distribution
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Roller Screw and Threaded Chain Speed Reducer: An Experimental Evaluation
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作者 Filiberto Gutiérrez 《Modern Mechanical Engineering》 2024年第1期1-11,共11页
We are developing a speed reducer that can be considered a transformation of a worm gear reducer: the worm is replaced by an inverted roller screw, and the gear is replaced by a threaded chain drive. This configuratio... We are developing a speed reducer that can be considered a transformation of a worm gear reducer: the worm is replaced by an inverted roller screw, and the gear is replaced by a threaded chain drive. This configuration lessens wear, increases load capacity, and improves efficiency. The threaded chain consists of nut-shaped links. This paper presents the results of tests carried out on a prototype with a reduction ratio of 46. 展开更多
关键词 Speed Reducer Inverted roller Screw Chain Drive Threaded Chain Drive
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Nonlinear Dynamics Behaviors of a Rotor Roller Bearing System with Radial Clearances and Waviness Considered 被引量:15
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作者 王黎钦 崔立 +1 位作者 郑德志 古乐 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第1期86-96,共11页
A rotor system supported by roller beatings displays very complicated nonlinear behaviors due to nonlinear Hertzian contact forces, radial clearances and bearing waviness. This paper presents nonlinear bearing forces ... A rotor system supported by roller beatings displays very complicated nonlinear behaviors due to nonlinear Hertzian contact forces, radial clearances and bearing waviness. This paper presents nonlinear bearing forces of a roller bearing under four-dimensional loads and establishes 4-DOF dynamics equations of a rotor roller bearing system. The methods of Newmark-β and of Newton-Laphson are used to solve the nonlinear equations. The dynamics behaviors of a rigid rotor system are studied through the bifurcation, the Poincar è maps, the spectrum diagrams and the axis orbit of responses of the system. The results show that the system is liable to undergo instability caused by the quasi-periodic bifurcation, the periodic-doubling bifurcation and chaos routes as the rotational speed increases. Clearances, outer race waviness, inner race waviness, roller waviness, damping, radial forces and unbalanced forces-all these bring a significant influence to bear on the system stability. As the clearance increases, the dynamics behaviors become complicated with the number and the scale of instable regions becoming larger. The vibration frequencies induced by the roller bearing waviness and the orders of the waviness might cause severe vibrations. The system is able to eliminate non-periodic vibration by reasonable choice and optimization of the parameters. 展开更多
关键词 roller bearing rotor system nonlinear bearing force dynamics behaviors BIFURCATION CHAOS
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Roller转子密炼机聚合物流体的混沌混合特性 被引量:11
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作者 程志飞 何延东 +2 位作者 朱向哲 孙大鹏 王阁 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2013年第12期128-132,共5页
建立了Roller转子密炼机二维有限元模型,利用网格重叠技术,对密炼机流体的流动过程进行了数值模拟。利用粒子示踪技术,采用4阶Runge-Kutta法计算了不同转数和不同流体粒子释放位置的密炼机Poincaré截面、平均对数线拉伸及Lyapunov... 建立了Roller转子密炼机二维有限元模型,利用网格重叠技术,对密炼机流体的流动过程进行了数值模拟。利用粒子示踪技术,采用4阶Runge-Kutta法计算了不同转数和不同流体粒子释放位置的密炼机Poincaré截面、平均对数线拉伸及Lyapunov指数等混沌混合参数。从非线性混沌理论的视角研究了Roller转子密炼机的混沌混合机理。结果表明,在双转子周期性扰动的作用下,聚合物流体在密炼机内被反复地拉伸、折叠,且啮合区的Poincaré截面出现了典型的"马蹄形"混沌结构。随着混合周期的增加,平均线拉伸以指数形式增长,且Lyapunov指数大于零。Roller转子密炼机流体具有混沌对流的特征。 展开更多
关键词 roller转子密炼机 混沌混合 POINCARÉ截面 LYAPUNOV指数
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Occurrence of Rice Leaf Roller in China and Its Identification and Prevention 被引量:4
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作者 罗守进 《Plant Diseases and Pests》 CAS 2010年第2期13-18,共6页
Rice leaf roller (Cnaphalocrocis medinalis Guenée) is a migratory pest, which mainly causes damage on rice. The morphology characteristic of rice leaf roller is introduced, which is also compared with the morph... Rice leaf roller (Cnaphalocrocis medinalis Guenée) is a migratory pest, which mainly causes damage on rice. The morphology characteristic of rice leaf roller is introduced, which is also compared with the morphology characteristic of the other insects such as Susumia exigua Butler and Tryporyza incertulas (walker). The occurrence law, living habit and selection of prevention pesticides against rice leaf roller in China are summarized, which will provide the intergrated situation of rice leaf roller in China for worldwide further research on the insect. 展开更多
关键词 Rice leaf roller IDENTIFICATION PREVENTION
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EQUATION OF MOTION FOR NOVEL FRICTION PENDULUM SYSTEM WITH DUAL ROLLERS 被引量:9
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作者 袁健 ROSCHKE Paul 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第4期276-280,共5页
A novel friction pendulum system (FPS) with dual rollers is studied based on the multibody dynamics theory. By analyzing kinematic characteristics of the system, it is reduced to a one degree-of-freedom system. Then... A novel friction pendulum system (FPS) with dual rollers is studied based on the multibody dynamics theory. By analyzing kinematic characteristics of the system, it is reduced to a one degree-of-freedom system. Then the equation of motion for the system is analytically derived by applying the theorem of the relative kinetic energy for a system of particles in differential form in the non-inertial reference system described as a nonlinear differential equation. In the case of the small angular displacement, the natural frequency of the corresponding undamped linear system is obtained, which is consistent with the experimental observation. The derived equation is useful for the study of dynamic characteristics of novel FPS, and its solution directly expedites the simulation of the system in a control loop, and further facilitates the semi-active control process including novel FPS. 展开更多
关键词 friction pendulum system with dual rollers seismic isolation analytical study multibody system
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炒烘结合工艺对烘青绿茶品质的影响
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作者 张荣祥 杜亚如 +4 位作者 张德 董智杰 倪德江 郑时兵 余志 《食品科学》 EI CAS 北大核心 2025年第1期90-99,共10页
以湖北宣恩县伍家台栽培茶一芽二、三叶鲜叶为实验原料,通过正交试验探究烘青绿茶加工过程中滚炒环节的温度、投叶量及茶叶水分含量对烘青产品品质的影响,采用主成分分析优化滚炒环节工艺参数,确定最优工艺。结果表明:综合32项指标提取... 以湖北宣恩县伍家台栽培茶一芽二、三叶鲜叶为实验原料,通过正交试验探究烘青绿茶加工过程中滚炒环节的温度、投叶量及茶叶水分含量对烘青产品品质的影响,采用主成分分析优化滚炒环节工艺参数,确定最优工艺。结果表明:综合32项指标提取的5个主成分累计贡献率为90.06%,以构建评价函数作为评判指标,结合主效应分析得到最佳工艺参数为:滚炒环节温度(150±5)℃、投叶量2 kg、炒制后水分质量分数25%;烘青绿茶经滚炒后,感官评价结果发现其外形、香气、滋味、叶底得分较未经滚炒处理的样品均有所提高,涩味降低;茶叶条索匀整度、紧细度更好。研究显示,对于烘青绿茶产品,在加工过程中增加滚炒工艺环节对提升烘青绿茶品质具有较好效果。 展开更多
关键词 烘青绿茶 滚炒环节 主成分分析
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圆柱滚子轴承内圈挡边与滚子球基面的优化设计
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作者 王志坚 宋佳伟 +2 位作者 李兴林 李健 常振 《轴承》 北大核心 2025年第1期55-60,共6页
考虑离心力、陀螺力矩、滚子偏斜以及套圈挡边与滚子球基面之间的润滑,建立联合载荷作用下圆柱滚子轴承力学分析模型,基于该模型分析了滚子球基面半径对轴承接触特性及发热量的影响,结果表明:随滚子球基面半径增大,接触点距离滚道表面越... 考虑离心力、陀螺力矩、滚子偏斜以及套圈挡边与滚子球基面之间的润滑,建立联合载荷作用下圆柱滚子轴承力学分析模型,基于该模型分析了滚子球基面半径对轴承接触特性及发热量的影响,结果表明:随滚子球基面半径增大,接触点距离滚道表面越近,最大接触应力越小,发热量越少。基于轴承寿命理论对不同偏差的内、外圈挡边倾角和滚子球基面半径进行匹配优化,轴承寿命可提升约34%。 展开更多
关键词 滚动轴承 圆柱滚子轴承 接触力 发热量 寿命 加工误差
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RV减速器滚针轴承动态磨损特性分析
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作者 许立新 刘伟明 钟家銮 《天津大学学报(自然科学与工程技术版)》 EI CAS 北大核心 2025年第1期56-67,共12页
RV(rotary vector)减速器中滚针轴承径向尺寸小,所受动态接触载荷变化复杂,在实际使用中容易出现磨损失效,导致RV减速器的工作性能急剧下降,失去原有的传动精度,甚至出现故障损坏.为揭示RV减速器滚针轴承动态磨损特性,基于接触多体动力... RV(rotary vector)减速器中滚针轴承径向尺寸小,所受动态接触载荷变化复杂,在实际使用中容易出现磨损失效,导致RV减速器的工作性能急剧下降,失去原有的传动精度,甚至出现故障损坏.为揭示RV减速器滚针轴承动态磨损特性,基于接触多体动力学和Archard磨损理论,提出摆线针轮-滚针轴承传动机构的动力学与磨损耦合模型.该方法通过接触多体动力学求解滚针轴承动态接触载荷,分别得到滚动体与内外滚道之间的瞬时法向接触力,借助Archard磨损模型依次计算出内外滚道的瞬时磨损量,再进行累积以表达轴承内外滚道磨损形状.以RV20E-121减速器为对象,基于摆线针轮-滚针轴承传动机构的动力学与磨损耦合模型,分析滚针轴承内外滚道的动态磨损特性,获得内外滚道的累积磨损量大小和分布情况,并绘制磨损后内外滚道形状.研究结果表明:轴承内外滚道磨损量不均匀,且内滚道磨损比外滚道严重;轴承内滚道在垂直偏心距方向上的累积接触磨损量较大,轴承外滚道在摆线轮圆周方向上累积接触磨损量较大;基于RV20E-121减速器耐久疲劳试验,通过轴承滚道磨损形状检测发现,内外滚道磨损不均匀,滚针轴承内滚道的磨损情况比外滚道严峻,内滚道的磨损主要集中在垂直偏心距方向上,外滚道的磨损集中在摆线轮圆周方向上,累积磨损规律与仿真计算结果具有一致性. 展开更多
关键词 RV减速器 滚针轴承 动力学 动态磨损
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Cement Grinding System Status of Roller Press
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作者 胡伟 王庆波 +2 位作者 李兵 丛茜 曲波 《Agricultural Science & Technology》 CAS 2012年第6期1328-1330,共3页
The working principle of cement roller press and current development of wear resistance on the cement grinding system status at home and abroad was described. The main improvement of previous research on the wear resi... The working principle of cement roller press and current development of wear resistance on the cement grinding system status at home and abroad was described. The main improvement of previous research on the wear resistance of roller press was proposed from three aspects of wear-resistant material, roller press roller structure, and surface morphology. 展开更多
关键词 Cement grinding system Grinding roller Bionic non-smooth Wear resistance
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外圈故障状态下动车组轴箱轴承振动响应影响因素分析
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作者 乔笑冉 梁树林 +2 位作者 杨晨 许文天 孙昭意 《轴承》 北大核心 2025年第1期111-117,共7页
针对轴箱轴承故障下的动力学响应问题,将滚子设为刚性体,其他部件设为柔性体,构建了带外滚道剥落故障的双列圆锥滚子轴承的刚柔耦合有限元模型,研究了故障尺寸、故障位置以及载荷变化对轴承动态响应的影响。结果表明:刚柔耦合模型既改... 针对轴箱轴承故障下的动力学响应问题,将滚子设为刚性体,其他部件设为柔性体,构建了带外滚道剥落故障的双列圆锥滚子轴承的刚柔耦合有限元模型,研究了故障尺寸、故障位置以及载荷变化对轴承动态响应的影响。结果表明:刚柔耦合模型既改善了全刚性体振动响应偏大的问题,又避免了全柔性体计算时间过长的缺点;轴承的故障尺寸越大,故障位置越接近承载区,轴承载荷越大,振动信号显示出的故障特征越明显,故障尺寸达到一定程度时故障特征将由单冲击变为双冲击;径向载荷对轴承故障响应的影响远大于轴向载荷。 展开更多
关键词 滚动轴承 轴箱轴承 双列圆锥滚子轴承 故障特征 振动响应 动力学仿真
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Banbury和Roller转子密炼机局部和全局混合特性 被引量:3
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作者 王春雷 王天书 +1 位作者 朱向哲 何延东 《工程塑料应用》 CAS CSCD 北大核心 2016年第1期75-80,共6页
采用有限元法,利用Polyflow软件计算了Banbury和Roller两种转子密炼机检测线的速度、剪切速率和混合指数分布,对比分析了两种转子的局部混合特性。通过计算停留时间分布、对数拉伸率、平均混合效率和粒子束分布指数等混合参数,对比分析... 采用有限元法,利用Polyflow软件计算了Banbury和Roller两种转子密炼机检测线的速度、剪切速率和混合指数分布,对比分析了两种转子的局部混合特性。通过计算停留时间分布、对数拉伸率、平均混合效率和粒子束分布指数等混合参数,对比分析了两种转子密炼机的全局混合特性。在此基础上,研究了具有典型运动规律流体粒子的动力学特性,分析了密炼机流体的位移和速度突变产生的受力和混合突变特征,为深入理解密炼机流体的复杂混合机理提供了一定的理论参考。 展开更多
关键词 密炼机 roller转子 Banbury转子 混合效率 数值模拟
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弹齿式辣椒采摘滚筒的分析与试验
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作者 沈晓凯 阿力木·买买提吐尔逊 +2 位作者 靳范 李谦绪 徐玉龙 《农机化研究》 北大核心 2025年第4期160-166,共7页
随着我国经济的不断发展,辣椒种植规模不断扩大,对于辣椒收获机械的需求日益增加。采摘滚筒是滚筒式辣椒收获机采摘台的主要工作总成之一,可通过对辣椒植株的高速梳刷完成采摘。为改善辣椒采摘装置的收获性能,对辣椒采摘过程进行受力分... 随着我国经济的不断发展,辣椒种植规模不断扩大,对于辣椒收获机械的需求日益增加。采摘滚筒是滚筒式辣椒收获机采摘台的主要工作总成之一,可通过对辣椒植株的高速梳刷完成采摘。为改善辣椒采摘装置的收获性能,对辣椒采摘过程进行受力分析,并借助Adams软件对采摘滚筒进行运动学分析,旨在为今后辣椒采摘装置的设计制造提供参考。同时,确定了采摘弹齿结构、转速等关键参数,对弹齿运动过程进行分析,通过理论分析确定滚筒转速的范围,并设计Box-Behnken试验。结果表明:在较优参数组合下,即前进速度6.4 km/h、预设弹齿间隙89 mm、滚筒转速180 r/min时,辣椒破损率优化值为2.4%,符合行业要求。 展开更多
关键词 辣椒 采摘滚筒 弹齿 仿真
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对辊式油茶果籽壳清选机的设计与试验
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作者 王东 寇欣 +3 位作者 廖伟 康地 曲振兴 汤晶宇 《农机化研究》 北大核心 2025年第2期105-113,164,共10页
针对现有油茶果籽壳清选机清选效果不佳、茶籽损伤率高问题,设计了一种采用齿光辊清选原理的对辊式油茶果籽壳清选机。同时,对油茶籽、壳的物理特性进行了研究,对清选装置辊组排布方式、齿光辊组数、清选关键部件齿辊齿形和直径分别进... 针对现有油茶果籽壳清选机清选效果不佳、茶籽损伤率高问题,设计了一种采用齿光辊清选原理的对辊式油茶果籽壳清选机。同时,对油茶籽、壳的物理特性进行了研究,对清选装置辊组排布方式、齿光辊组数、清选关键部件齿辊齿形和直径分别进行了设计,分析了清选状态时油茶壳受力情况。为验证对辊式油茶果籽壳清选机是否达到了预期设计目标,设计了三因素三水平正交试验,选取清选间隙、辊轴转速、喂入量为试验因素,以茶籽破碎率和清选率为评价指标,对清选机进行现场试验。结果表明:清选间隙为3.13 mm、轴辊转速为298.25 r/min、喂入量为1.51 t/h时,对辊式油茶果籽壳清选机获得最佳清选效果,此时茶籽破损率为3.30%,清选率为96.79%。 展开更多
关键词 油茶果籽壳混合物 清选机 齿光辊清选
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Clearance Influence on Dynamic Response of Intermittent Roller Chain Drive 被引量:11
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作者 XU Lixin YANG Yuhu +2 位作者 CHANG Zongyu SHEN Zhaoguang LIU Jianping 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2010年第6期699-708,共10页
The clearances appear in chain link hinges induced by manufacturing tolerance or wear of components are the most important factor that influences the dynamic performance of the intermittent roller chain drives. Due to... The clearances appear in chain link hinges induced by manufacturing tolerance or wear of components are the most important factor that influences the dynamic performance of the intermittent roller chain drives. Due to the existence of the clearances in chain link hinges, the serious impact vibration phenomenon which influences the stability and the position accuracy of the chain drive system would be caused in the intermittent motion. But, the problem may be that a reasonable modeling on the chain with clearances is difficult due to the large clearance's number in chain system and the fact that the clearance' size are different. Currently, the studies on the dynamics of the intermittent roller chain considering the multi-clearance' joints are rare. Most research works have only focused on the constant moving chains. Taking the intermittent roller chain system as an object, this paper designs and builds the experimental device of this kind of mechanical system. The Longitudinal vibration response of the intermittent chain under the different motion laws was tested. The experimental study shows that the clearances presented in chain link hinges can cause severe impact vibration in the intermittent motion of chain. In subsequent work, the dynamic model of the intermittent roller chain system with the multi-clearance' joints was established. By calculating the dynamic response of this kind of mechanical system under the different motion laws, the effect of the clearances on the dynamic response of the intermittent chain drive system was analyzed. The theoretical simulation shows that the serious impact vibration phenomenon of the chain system can be caused by the clearances at the start accelerating period, and the chain drive system is often accompanied by the severe shock and vibration at the moment that the chain moves from the acceleration period to deceleration period. The research conclusions made by the experimental and theoretical studies indicate that the use of motion laws with small and continuous jerk at conversion point can effectively suppress the impact vibration at this point caused by clearances' effect. Additionally, the use of nonsymmetrical motion laws with small jerk approaching the end of the indexing period can obtain a smaller residual vibration. The presented motion law can provide an important reference for the improvement of the dynamic performance of the intermittent chain drive systems. 展开更多
关键词 roller chain CLEARANCE intermittent motion motion law
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Kinematics and Path Following Control of an Articulated Drum Roller 被引量:12
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作者 Yongming BIAN Meng YANG +1 位作者 Xiaojun FANG Xiahui WANG 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第4期888-899,共12页
Automatic navigation of an articulated drum roller, which is an articulated steering type vehicle widely used in the construction industry, is highly expected for operation cost reduction and improvement of work effi-... Automatic navigation of an articulated drum roller, which is an articulated steering type vehicle widely used in the construction industry, is highly expected for operation cost reduction and improvement of work effi- ciency. In order to achieve the path following control, considering that its steering system is articulated steering and two frames are articulated by an active revolute joint, a kinematic model and an error dynamic state-space equation of an articulated drum roller are proposed. Besides, a state- feedback control law based on Lyapunov stability theory is also designed, which can be proved to achieve the purpose of control by the analysis of stability. What's more, to evaluate the performance of the proposed method, simu- lation under the MATLAB/Simulink and experiments using positioning algorithm and errors correction at the uneven construction site are performed, with initial dis- placement error (-1.5 m), heading error (-0.11 tad) and steering angle (-0.19 rad). Finally, simulation and exper- imental results show that the errors and steering angle can decrease gradually, and converge to zero with time. Meanwhile, the control input is not saturated. An articu- lated drum roller can lock into a desired path with the proposed method in uneven fields. 展开更多
关键词 KINEMATICS Path following controlArticulated drum roller Positioning algorithmPositioning errors correction
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Dynamic Modeling of a Roller Chain Drive System Considering the Flexibility of Input Shaft 被引量:7
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作者 XU Lixin YANG Yuhu1 +1 位作者 CHANG Zongyu LIU Jianping 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2010年第3期367-374,共8页
Roller chain drives are widely used in various high-speed, high-load and power transmission applications, but their complex dynamic behavior is not well researched. Most studies were only focused on the analysis of th... Roller chain drives are widely used in various high-speed, high-load and power transmission applications, but their complex dynamic behavior is not well researched. Most studies were only focused on the analysis of the vibration of chain tight span, and in these models, many factors are neglected. In this paper, a mathematical model is developed to calculate the dynamic response of a roller chain drive working at constant or variable speed condition. In the model, the complete chain transmission with two sprockets and the necessary tight and slack spans is used. The effect of the flexibility of input shaft on dynamic response of the chain system is taken into account, as well as the elastic deformation in the chain, the inertial forces, the gravity and the torque on driven shaft. The nonlinear equations of movement are derived from using Lagrange equations and solved numerically. Given the center distance and the two initial position angles of teeth on driving and driven sprockets corresponding to the first seating roller on each side of the tight span, dynamics of any roller chain drive with two sprockets and two spans can be analyzed by the procedure. Finally, a numerical example is given and the validity of the procedure developed is demonstrated by analyzing the dynamic behavior of a typical roller chain drive. The model can well simulate the transverse and longitudinal vibration of the chain spans and the torsional vibration of the sprockets. This study can provide an effective method for the analysis of the dynamic characteristics of all the chain drive systems. 展开更多
关键词 roller chain dynamic modeling Lagrange equations
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THE 3-D BOUNDARY ELEMENT METHOD OF ROLLER BEARING BY PLATE ELEMENT ANALOGUE 被引量:9
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作者 Shen Guangxian Shu xuedao Li Ming 《Acta Mechanica Solida Sinica》 SCIE EI 2001年第3期268-274,共7页
The mill roller bearing is made up of an internal ring, middlerolls and an external ring, the analysis of which is a multi-bodiescontact problem. In this paper, based on the three-dimensionalelastic contact BEM withou... The mill roller bearing is made up of an internal ring, middlerolls and an external ring, the analysis of which is a multi-bodiescontact problem. In this paper, based on the three-dimensionalelastic contact BEM without friction, and using the structuralcharacteristics of roller bearings, middle rolls are de- scribed byelastic plate units of different shapes, which is placed on theinternal ring. 展开更多
关键词 roller bearing traction sub-element method elastic plate element
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Study of Stress and Strain Distributions of First Pass Conventional Spinning Under Different Roller-trace 被引量:7
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作者 LIU Jian-hua, YANG He, LI Yu-qiang (College of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期62-,共1页
Based on simplified axisymmetrical forming model, a elasto-plastic FEM simulation system of multi-pass conventional spinning is developed. Taking the typical draw-spinning as the study object, and establishing reasona... Based on simplified axisymmetrical forming model, a elasto-plastic FEM simulation system of multi-pass conventional spinning is developed. Taking the typical draw-spinning as the study object, and establishing reasonable mechanics model, research on the first pass of spinning process is carried out with FEM system developed. The distributions of the stress and strain are obtained by three types of roller-trace curves: straight line, involute curves and quadratic curves. The results are as follows: (1) The values of equivalent stress and strain are the lowest under involute curve compared to other two curves, and they change relatively small and decrease with the increase of radius. The values of equivalent stress and strain is the highest under quadratic curves, and increase with the increase of radius. (2) The value of radial stress is smallest under involute curve, and is the largest under straight line. Value of radial stress is often used as the criterion of cracking limit, so its distribution laws can provide references for studying the condition of cracking in multi-pass conventional spinning under different roller-trace. (3) Tangential stress is compressive stress. Absolute value of tangential stress is the smallest under involute curve, and values of tangential stress are close between other two curves. The distribution laws of tangential stress can serve as a significant guide to research the critical condition of wrinkling in multi-pass conventional spinning under different roller-trace. (4) The reduction of thickness is the smallest under involute curve. The distribution of the thickness strain is very unequal under quadratic curves. The results obtained can provide references for selecting reasonable roller-trace in multi-pass conventional spinning. 展开更多
关键词 multi-pass conventional spinning roller traces stress and strain distributions numerical simulation
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Control of thermal crown in the roller inside the continuous annealing furnace 被引量:6
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作者 HU Guangkui 《Baosteel Technical Research》 CAS 2009年第1期51-55,共5页
In a continuous annealing furnace, the hearth rollers are affected by heat, which in turn affects the stable operation of the steel strips. In order to ensure the stable operation of the steel strips the ability of th... In a continuous annealing furnace, the hearth rollers are affected by heat, which in turn affects the stable operation of the steel strips. In order to ensure the stable operation of the steel strips the ability of the rollers to correct themselves and to prevent the steel strips from buckling, effective measures are required to control the surface crown of the rollers inside the furnace. Starting from production, this study analyzes the way in which the crown of the hearth rollers inside the continuous annealing furnace changes. The study suggests control measures to prevent buckling and and misalignment. The study definitely provides guidance to the stable operation of steel strips in continuous annealed furnaces. 展开更多
关键词 hearth roller roll crown MISALIGNMENT BUCKLING
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