Dual cycloid gear mechanism for automobile safety pretensioners

The most conventional vehicle pretensioner system consists of an internal gear pair with involute teeth. However, it has been well known that the corresponding gear pairs are relatively weak under the situation of impact loadings. To improve this phenomenon, a new pretensioning gear system with cycloid teeth rather than the involute ones was proposed, and dual cycloidal gear mechanisms were designed for satisfying geometric constraints and dynamic loading conditions. The simulations of the prototypes were conducted by LS-DYNA program and the experiments for a prototype were performed for a dynamic model with impact loading devices. The results show that the better operation and the smoother motion are confirmed in the proposed cycloidal gear system rather than the conventional one without interferences between gear teeth under the impact of a crash.

Y 7663 CYCLOID GEAR

This machine tool is produced by theQinchuan Machine Tool Works. It isused mainly for grinding cycloid gearsin the cycloidal speed reducer. The toothflank of the gear is the equi-distance curve ofmetamorphic epicycloid. The structural features of the machinetool are: the machine adopts the generatingprinciple for grinding; the table surface isprovided with a V-type circular guideway,so as to guarantee a stable working accuracy;the column unit employs a ballscrew

EFFICIENCY ANALYSIS OF DOUBLE CRANK RING-PLATE-TYPE PIN-CYCLOIDAL GEAR PLANETARY DRIVE

From the general formula for calculating the efficiency of planetary geartrains, the efficiency of the double crank ring-plate-type pin-cycloidal gear planetary drive isderived. To prove the theory, an experimental study has been conducted. The tested value of theefficiency of a sample set of the new-type drive in the experiment agrees with the calculated one.It shows that the new-type drive is of not merely high bearing capacity, but also quite highefficiency.

Cycloidal Magnetic Gear Speed Reducer

A cycloidal speed reducer employing gears with permanent magnets acting as teeth is described. The magnets, which have their axes radially oriented in both the orbiting gear and the fixed internal gear, are inserted in holes drilled in nonmagnetic rims without protruding from the cylindrical exposed surfaces. Because the orbiting gear is not restrained radially, it contacts the fixed gear and rolls on its inner surface. A normal force is developed at the contact point between the gears to balance the magnetic attraction and the centrifugal force of the orbiting gear. The friction available due to this normal force increases the transmission’s torque capacity, which is further increased by elimination of the gap between the gears. Also, the radial load on the supporting orbiting gear bearing is eliminated. A prototype with a reduction ratio of 26 is being tested.

Smooth Operation with Manufacture Error and Modification of Cycloidal Pin Gearing

The paper considers the modification or the manufacture error of cycloidal gear, then analyzes the relationship of pin circle meshed with the modified cycloidal gear, discuases the amount of error that leads to destroying conjugate action and results in the changes of tbe instantaneous velocity ratio and so as to affect the smooth operation of cycloidal pin gearing. The idea of the relationship between amount of modification aud manufacture error and the smooth operation can be gotten from the curve diagrams of the instantaneous velocity ratio. Therefore, the directions for improving the reature of the cycloidal pin gear transmission are clear.

ERROR PROCESSING METHOD OF CYCLOIDAL GEAR MEASUREMENT USING 3D COORDINATES MEASURING MACHINE

An error processing method is presented based on optimization theory and microcomputer technique which can be successfully used in the cycloidal gear measurement on three dimensional coordinates measuring machine (CMM). In the procedure, the minimum quadratic sum of the normal deviation is used as the object function and the equidistant curve is dealed with instead of the teeth profile. CMM is a high accurate measuring machine which can provide a way to evaluate the accuracy of the cycloidal gear completely.

Research of the Pressure Angle for Whole Cycloidal Gears

The working profile of whole cycloidal gear is made up of epicycloid and hypocycloid entirely, according to the theory of meshing of gears and the properties of the cycloid, deals with the derivation of the pressure angle formula for the whole cycloidal gear in theory, and reveals changes of the pressure angle of whole cycloidal gear through examples, finds the application relationships between the pressure angle and other design parameters of the whole cycloidal gear, proves the possibility that the whole cycloidal gear can be used in internal parallel move gear mechanism, also provides theoretic fundament for designing internal parallel move whole cycloidal gear correctly.

摆线轮工作齿廓的二次分段修形方法

针对常规修形方法存在计算复杂、齿廓曲线形状控制不够灵活等问题,提出了一种摆线轮工作齿廓的二次分段修形方法。通过摆线轮齿廓压力角变化规律的分析,将工作齿廓最小压力角的位置作为二次分段修形的基准点,建立二次分段修形模型。利用直线法简单函数,推导出二次分段修形方法下各齿段修形量的计算公式及齿廓方程。采用轮齿接触分析的方法,研究了二次分段修形齿廓的传动误差和回差,并进行对比实验验证摆线轮工作齿廓二次分段修形方法的正确性和可行性。结果表明:二次分段修形的摆线轮工作齿廓与理论齿廓曲线更加吻合,传动误差和回程误差分别减少约14%和19%。

考虑齿形误差影响的摆线针轮承载特性分析

针对缺乏考虑齿形误差的承载分析软件,导致分析结果不符合实际工程状况的问题,提出了1种包含摆线轮齿形误差的摆线针轮副承载特性分析方法。利用三次非均匀B样条准确描述出包含齿形误差的摆线轮实际齿廓,构建并分析了摆线针轮误差齿廓接触分析模型(error tooth contact analysis,E-TCA),得到了初始啮合位置参数及啮合间隙。在此基础上,建立了齿形误差影响下的摆线针轮副负载接触分析模型,确定了零部件多体接触之间的力矩平衡和变形协调关系,利用能量最低原理获取了真实承载特性。通过有限元模型验证了RV-40E型号减速器的摆线针轮承载特性。结果表明:由于齿形误差的影响,啮合齿数减少了1对,啮合应力和传动误差增大了5.3%和5.7%。

双摆线针齿传动齿廓特性与啮合特性分析

将双摆线齿廓运用到NN型少齿差行星齿轮传动领域,通过分析内外摆线轮齿廓的凹凸性、曲率和曲率半径,获得了内、外摆线齿廓的特性;通过图解法推导双摆线针齿传动中内、外摆线轮的压力角计算公式,获得了啮合过程压力角变化规律,以及双摆线针齿主要参数对于内、外摆线轮压力角的影响;通过对等距修形和移距修形进行研究,表明齿廓修形对齿形有明显影响。

基于压力角的摆线针轮齿廓曲线优化方法

根据摆线针轮传动理论,提出一种基于压力角的齿廓优化方法。将摆线针轮齿廓分为工作段与非工作段,区分影响工作段压力角的因素为修形参数与设计参数,讨论两类参数对压力角的影响,以此两类参数为设计变量,以工作段平均压力角为目标函数,以运动与润滑要求确定边界条件,对RV⁃550E型减速器摆线轮进行优化设计。结果表明,此方法使算例的工作段平均压力角降低了4.14%,使单齿啮合过程的压力角最大值降低了1.35%,优化前后接触齿对最大Mises应力下降了20.77%,发生位置由摆线轮转移至针轮,模型质量减小了9.38%,在确保无根切现象的同时能获得良好的组合修形效果。

RV减速器摆线轮齿廓修形对温度的影响

为分析摆线轮啮合过程中的温度特性,研究不同修形方式对摆线轮温度的影响规律,考虑摆线齿轮常用的3种组合修形方式,以相同的径向间隙为前提,对比分析摆线轮修形前后的接触应力与摩擦热量在轮齿上的分布情况。利用有限元分析,计算出修形前后温度场中的温度分布情况。结果表明:对摆线齿轮进行齿廓修形可以有效降低齿轮的稳态温度,组合修形中降温效果最佳的修形方式为正等距+正移距修形;单齿上温度梯度的密集程度随着啮合范围的减小而增大;摆线轮修形前后瞬时摩擦热量的最大值不受影响,峰值所处的位置会发生变化,而周期摩擦热量的峰值位于轮齿的同一啮合相位角上,但数值会随着轮齿受到的压力的增大而增大。

双摆线针齿传动的齿廓特性与啮合特性分析

为了解决传统的摆线针齿传动输出结构易损坏、结构复杂等问题,将内、外摆线齿廓运用到NN型少齿差行星齿轮传动领域,提出了一种新型的摆线针排齿轮,并进行了其齿廓特性和啮合特性分析。对摆线轮的齿廓方程、压力角进行公式推导,分析了齿廓参数对压力角的影响,为该新型传动系统的应用奠定基础;对不同齿廓修形方法下的内外摆线齿轮进行参数方程推导,并利用Matlab软件进行仿真分析,以解决由于润滑黏膜、制造误差等一系列原因所产生的啮合间隙问题;最后,对双摆线针齿传动进行力学特性分析,为后续的减速器设计和有限元分析提供了理论基础。研究对开发新的传动方式具有意义和工程使用价值。

基于IAS信号自适应窄带解调的RV减速器摆线轮故障特征提取

RV(rotary vector)减速器广泛应用于工业机器人,研究其关键零部件的故障检测方法具有重要意义。由于RV减速器结构复杂、摆线轮转速低、故障冲击较弱等问题,造成摆线轮故障特征难以用常规振动分析方法提取。针对上述问题,提出一种基于瞬时角速度信号自适应窄带解调的RV减速器摆线轮故障特征提取方法。首先对编码器角度信号进行采集,然后使用向前差分法获得瞬时角速度信号,在此基础上,使用角域同步平均提取摆线轮周期相关同步分量,消除非同步干扰,并通过构建边带信噪比指标选取故障信息丰富的啮合谐波频带进行带通滤波,最后对滤波后的信号进行窄带解调,实现对RV减速器摆线轮的故障特征提取。试验结果表明,该方法可以有效地提取RV减速器摆线轮故障特征,且自适应实现优化带宽选择。

基于改进MOPSO的RV减速器摆线轮齿廓多目标修形研究

在精密RV减速器摆线轮修形过程中,RV减速器回差和传动误差难以获得综合提升,且摆线轮的修形方式多为单目标修形或加权单目标修形,不符合实际工程情况。为此,采用TCA法建立传动误差模型和回差模型,提出一种带有指数型非线性递减惯性权重和迭代更新学习因子的多目标粒子群算法。以回差和传动误差为目标函数,利用改进算法进行复合修形量的优化,通过隶属度函数获得最优化解。利用Adams和MATLAB分别分析不同修形方法下RV减速器的回差和传动误差情况。结果表明:最终优化修形后的回差比等距、移距修形分别减少了0.02′、0.04′,传动误差分别减少了6.6%、7.8%。

精密减速器摆线轮制造误差的数字化测量

摆线轮的制造误差是影响精密减速器传动精度的重要因素。基于使用一维测头的齿轮测量中心提出了一种精密减速器摆线轮制造误差的数字化测量方法,该方法能够快速而精确的实现摆线轮制造误差的测量。通过建立摆线轮的理论齿廓模型和误差测量模型,计算得到了测头的理论运动轨迹。根据精密测量原理,通过采取实际齿廓的NURBS拟合以及实际齿廓与理论齿廓的最佳匹配处理,构建了摆线轮制造误差精确计算过程及制造误差处理的数学模型,通过采用优化迭代算法求解得到了摆线轮的实际制造误差。在国产JB45型齿轮测量中心上对摆线轮的实际齿廓进行了实际检测,验证了该方法的准确性和有效性。

基于共轭修形的大模数摆线齿锥齿轮齿面建模及承载性能分析

针对大模数摆线齿锥齿轮在专用铣齿机上难以加工的问题,提出一种面向加工中心的摆线齿锥齿轮齿面模型构建方法。基于摆线齿锥齿轮加工原理,根据刀具与大轮之间的几何位置关系,建立大轮切齿参数计算方法;根据大轮切齿加工数学模型,推导大轮理论齿面,并通过齿面离散方法获得大轮数值齿面;基于齿轮啮合数学模型推导出与大轮完全共轭的小轮齿面,通过在完全共轭小轮齿面法线方向上构建二阶修形差曲面并进行叠加,获得与大轮齿面呈局部共轭的小轮数值齿面。最后,建立有限元齿面加载接触分析流程,以一对矿用减速器大模数摆线齿锥齿轮副为例,利用ABAQUS软件进行齿轮三维建模和有限元加载接触仿真。结果表明:在实际加载工况下,通过共轭修形构建的小轮齿面与大轮齿面呈局部内对角接触,并且加载接触区受啮合错位影响在大轮齿面内部移动,未脱离齿面产生边缘接触,齿面接触区满足工程需要。仿真结果验证了共轭齿面修形建模方法的可行性。

低滑动率摆线正齿轮啮合特性与疲劳寿命研究

为提高齿轮的传动性能,基于啮合线原理提出了一种低滑动率摆线正齿轮。首先通过齿轮啮合原理推导出摆线正齿轮齿廓与过渡曲线方程;然后基于齿廓参数与重合度公式计算得出其最大重合度为3.0134;最后分析了摆线正齿轮啮合过程中的稳定性、接触应力和疲劳寿命。结果表明,高重合度摆线齿轮齿间切向啮合力为1238.2 N,与相同工况下的渐开线标准齿轮相比,减小了5.24%;通过疲劳寿命分析可知,最小疲劳寿命为4.534×10^(6)次,齿面接触应力主要集中在齿轮啮合位置以及齿根部位,因此疲劳破坏易发生于主动轮与从动轮啮合处以及齿根部位。

某型航空发动机滑油泵转子参数对泵性能的影响

为了研究滑油泵转子设计参数对泵的性能影响,采用数值仿真软件Pumplinx对某型航空发动机滑油泵供油级进行了三维数值模拟,具体研究了内啮合摆线滑油泵转子结构设计参数对其流量及流量脉动率的影响。结果表明,当泵的体积及边界条件一定时:随着转速增加,流量脉动幅值与流量脉动率均随之增大;偏心距e减小,流量脉动率减小;创成系数k的增大能够使泵的排量增大;弧径系数h的减小会使排量增大;弧径系数h及创成系数k单独的变化对流量脉动率无直接影响,需结合起来判断转子是否过尖,过尖的转子会使流量脉动率增大。

摆线齿轮执行机构传动性能研究

执行机构作为EV减速器和混动变速器的重要组成部分,其性能的优劣不仅关系到传动系统的换挡可靠性,还影响整车的行驶舒适性。目前,国内针对多挡减速器和混动变速器执行机构的性能要求不断提高,亟需在这领域进行性能提升研究工作。基于减速器和混动变速器的换挡需求,设计开发了一套采用无刷电机的摆线齿轮执行机构。通过摆线齿轮齿形修形设计,搭建了多体动力学模型并分析了摆线齿轮传动机构的传动效率及疲劳强度,并开展了相关试验验证,取得了良好效果。