在线修复烧结机和链篦机星轮齿板的实践

山钢日照公司为满足大高炉对烧结矿和球团矿的物料需求,针对烧结机星轮齿板和链篦机星轮齿板结构特点、焊接性特点以及使用性能要求,在设备年修过程中,通过合理选择焊接材料、控制焊接热输入和熔合比等工艺措施,在线进行堆焊,使用靠模打磨,实现了星轮齿板在线修复。焊接修复后的星轮齿板表面硬度40~43 HRC,满足生产需求。

烧结机大型星轮齿板焊接修复技术

针对烧结机星轮齿板50Mn2的结构特点、焊接性特点及其使用性能要求,在设备不拆卸下线、焊前不预热、焊后不进行热处理的工况条件下,采用ENiCrMo-3焊条、控制焊接热输入(打底焊道8 kJ/cm以下,其余焊道10 kJ/cm)、锤击焊缝等工艺措施,可实现星轮齿板在线焊接修复。焊接修复后齿板表面硬度可稳定在40~43 HRC,满足烧结机的生产要求,使用寿命与更换新齿板相当,修复成本仅为更换新齿板的5%左右。

蜗杆压缩机星轮齿面分析及制造关键技术研究

分析了蜗杆压缩机啮合副中星轮齿面的组成,给出了包络面和轨迹面方程,讨论了星轮齿廓的径向滚切干涉。指出星轮齿廓无法采用精确展成加工获得,并提出了用极限轨迹面代替包络面的星轮加工方法,建立了星轮加工原理误差的计算方法和优化控制模型。理论研究及试验表明:提出的星轮齿廓加工方法,具有刀具易于制作、加工精度易于控制、生产成本低等优点。

单螺杆压缩机星轮齿磨损问题的研究

单螺杆压缩机由于其星轮齿的快速磨损,而未能在市场上显示出其应有的优点。星轮齿的磨损问题已成为制约单螺杆压缩机进一步发展的技术瓶颈。结合星轮齿磨损问题的研究历史,本文在对大量失效星轮齿调研分析的基础上,对星轮齿的磨损行为进行了分析,发现加工精度的提高和星轮齿材料的改进无法解决星轮齿磨损的根本问题。星轮齿磨损的必然原因是星轮齿前后侧不平衡的油膜力附加于星轮的正向圆周力。提出需要从两方面着手以提高星轮齿寿命:(1)型线的改进,并结合改种型线啮合副的加工,如多圆柱包络啮合副;(2)是基于油膜作用力的型线参数优化设计,以减小或消除油膜附加力对星轮齿的作用。目前,多圆柱包络啮合副单螺杆压缩机已进入样机试制阶段,有望全面提高星轮齿寿命。

烧结机星轮齿板更换技术

介绍了一种简单科学、快速精准更换烧结机星轮齿板的技术方法。

偶数齿带式烧结机的研究

研究的偶数齿带式烧结机的星轮，是将星轮齿设计成偶数个，由匀速齿齿廓曲线和复合齿（加速、匀速齿组合）齿廓曲线组成的齿廓，相间排列成的新型烧结机星轮。给出与之相匹配的该机头尾星轮弯道曲线方程。实现了台车列的匀速运动及单台车的追赶运动。可为偶数齿烧结机设计和奇数齿烧结机改造提供理论依据和实用参考。

烧结机台车起拱原因分析及处理

韶钢5#360m^2带式烧结机回程台车起拱现象严重。通过在烧结生产过程中,测量回程台车的不同起拱髙度,观察其运行趋势,同时在停机时测量尾部弯轨面与齿板面的关键点数据,从力学上分析引起台车起拱的原因,提出更换尾部星轮齿板、调整弯道与齿板间隙、同步调整水平轨道“压轨”等解决方案。实践结果表明:处理措施实施后,台车起拱髙度由均值35mm下降至5mm以下,因起拱造成的髙电流运行均值下降至40A,有效稳定了设备和生产。

湘钢90m^2烧结机消除台车起拱的实践

分析了湘钢90m2烧结机台车起拱的原因，介绍了该厂消除台车起拱的具体做法．

Finite Element Analysis of Internal Gear in High-Speed Planetary Gear Units

The stress and the elastic deflection of internal ring gear in high-speed spur planetary gear units are investigated. A rim thickness parameter is defined as the flexibility of internal ring gear. Six evenly spaced linear springs are used to describe the fitting status between internal ring gear and the gearcase. The finite element model of the whole internal ring gear is established by means of Pro/E and ANSYS. The loads on meshing teeth of internal ring gear are applied according to the contact ratio and the load-sharing coefficient. With the finite element analysis (FEA), the influences of flexibility and fitting status on the stress and elastic deflection of internal ring gear are predicted. The simulation reveals that the principal stress and deflection increase with the decrease of rim thickness of internal ring gear. Moreover, larger spring stiffness helps to reduce the stress and deflection of internal ring gear. Therefore, the flexibility of internal ring gear must be considered during the design of high-speed planetary gear transmissions.

Dynamic load sharing characteristics and sun gear radial orbits of double-row planetary gear train

A new non-linear bending-torsional coupled model for double-row planetary gear set was proposed, and planet's eccentricity error, static transmission error, and time-varying meshing stiffness were taken into consideration. The solution of differential governing equation of motion is determined by applying the Fourier series method. The behaviors of dynamic load sharing characteristics affected by the system parameters including gear eccentricities error, ring gear's supporting stiffness, planet's bearing stiffness, torsional stiffness of first stage carrier and input rotation rate were investigated qualitatively and systematically, and sun gear radial orbits at first and second stage were explored as well. Some theoretical results are summarized as guidelines for further research and design of double-row planetary gear train at last.

Analysis of lubrication performance for internal meshing gear pair considering vibration

The thermal elasto-hydrodynamic lubrication characteristics of the internal meshing gears in a planetary gear train under vibrations were examined considering the influence of the modification coefficient and time-varying meshing stiffness.Based on dynamic theory of the gear system,a dynamic model of the planetary gear train was established.The lubrication performances of modified gear systems under vibrations and static loads were analyzed.Compared with other transmission types,the best lubrication effect could be produced by the positive transmission.A thicker lubricating oil film could be formed,and the friction coefficient and oil film flash temperature are the smallest.Increasing modification coefficient improves the lubrication performance continuously but intensifies the engage-in and tooth-change impact.For the planetary and inner gears,the increase in the modification coefficient also leads a decrease in the oil film stiffness.

Stability of motion state and bifurcation properties of planetary gear train

A nonlinear lateral-torsional coupled vibration model of a planetary gear system was established by taking transmission errors,time varying meshing stiffness and multiple gear backlashes into account.The bifurcation diagram of the system's motion state with rotational speed of sun gear was conducted through four steps.As a bifurcation parameter,the effect of rotational speed on the bifurcation properties of the system was assessed.The study results reveal that periodic motion is the main motion state of planetary gear train in low speed region when ns<2 350 r/min,but chaos motion state is dominant in high speed region when ns>2 350 r/min,The way of periodic motion to chaos is doubling bifurcation.There are two kinds of unstable modes and nine unstable regions in the speed region when 1 000 r/min<ns<3 000 r/min.

Configuration design and control of hybrid tracked vehicle with three planetary gear sets

The hybrid tracked vehicles(HTV)usually adopt series hybrid powertrain with extra steering mechanism,which has relatively low transmission efficiency and reduces the flexibility of structural arrangement.To overcome the disadvantages,a new kind of single-mode powertrain has been proposed.The power-split hybrid powertrain is composed of three planetary gear(PG)sets connected to one engine,left and right track outputs,and three motors.The proposed powertrain can realize steering while going forward by controlling the output torque on each side without extra steering mechanism or steering shaft.Due to the diversity of the connection way between components and planetary gear sets,a rapid configuration design approach is proposed for the design selection of HTV.The automated dynamic modelling method can show the one-to-one correspondence with the selected feasible groups by establishing two characteristic matrices,which is more simple than other researches.The analytically-based method is proposed to classify all possible connection designs into several groups to decrease the searching scope with improved design efficiency.Finally,the optimal control strategy is used to find the design with optimal fuel economy under typical condition of HTV.The case study is implemented by the proposed design approach which demonstrates better design performances compared with the existing series-hybrid HTV.

Bifurcation and chaos study on transverse-torsional coupled 2K-H planetary gear train with multiple clearances

A new non-linear transverse-torsional coupled model was proposed for 2K-H planetary gear train, and gear's geometric eccentricity error, comprehensive transmission error, time-varying meshing stiffness, sun-planet and planet-ring gear pair's backlashes and sun gear's bearing clearance were taken into consideration. The solution of differential governing equation of motion was solved by applying variable step-size Runge-Kutta numerical integration method. The system motion state was investigated systematically and qualitatively, and exhibited diverse characteristics of bifurcation and chaos as well as non-linear behavior under different bifurcation parameters including meshing frequency, sun-planet backlash, planet-ring backlash and sun gear's bearing clearance. Analysis results show that the increasing damping could suppress the region of chaotic motion and improve the system's stability significantly. The route of crisis to chaotic motion was observed under the bifurcation parameter of meshing frequency. However, the routes of period doubling and crisis to chaos were identified under the bifurcation parameter of sun-planet backlash; besides, several different types of routes to chaos were observed and coexisted under the bifurcation parameter of planet-ring backlash including period doubling, Hopf bifurcation, 3T-periodic channel and crisis. Additionally, planet-ring backlash generated a strong coupling effect to system's non-linear behavior while the sun gear's bearing clearance produced weak coupling effect. Finally, quasi-periodic motion could be found under all above–mentioned bifurcation parameters and closely associated with the 3T-periodic motion.

Dynamic load sharing behavior of transverse-torsional coupled planetary gear train with multiple clearances

A new nonlinear transverse-torsional coupled model with backlash and bearing clearance was proposed for planetary gear set. Meanwhile, sun gear and planet's eccentricity errors, static transmission error, and time-varying meshing stiffness were taken into consideration. The differential governing equations of motion were solved by employing variable step-size Rung-Kutta numerical integration method. The behavior of dynamic load sharing characteristics affected by the system parameters including input rate, sun gear's supporting stiffness and eccentricity error, planet's eccentricity error, sun gear's bearing clearance, backlashes of sun-planet and planet-ring meshes were investigated qualitatively and systematically. Some theoretical results are summarized at last which extend the current understanding of the dynamic load sharing behavior of planet gear train, enrich the related literature and provide references for the design of planetary gear train.

Influence of support stiffness on vibrations of a planet gear system considering ring with flexible support

Planet gear systems(PGSs)are key components of transmission mechanisms.Structural and material characteristics of gearbox and shaft can affect the support stiffness and vibrations of PGSs.The ring gear flexibility should affect the vibrations of PGSs too.However,most previous work did not completely consider the effects of the ring gear flexibility on the vibrations of PGSs and flexible supports of ring and sun gears.Thus,this paper presents a flexible-rigid coupling multi-body dynamic(FMBD)model for a PGS with the flexible supports and ring gear flexibility.A finite element model of ring gear is established to formulate the ring gear flexibility.The influences of clearance and damping of planet bearings on the vibrations of PGS are considered.The effects of flexible supports and ring gear flexibility on the vibrations of PGS under different moment and speed conditions are studied.The statistical parameters and peak frequencies of PGS from the proposed FMBD and previous rigid multi-body dynamic(RMBD)models are compared.The results denote that the flexible support has a great effect on the vibrations of PGS.This paper can provide some guidance for the support structure design and vibration control for PGSs.

Optimum Determination of Partial Transmission Ratios of Coupled Planetary Gearboxes

This paper presents a new study on optimum determination of the partial ratios of coupled planetary gear sets for getting minimum radial size of the gear sets. In this paper, based on moment equilibrium condition of a mechanic system including two-row planetary gear sets and their regular resistance conditions, an explicit model for calculating the partial ratios of coupled planetary gear sets was proposed. In addition, by giving this effective model, the partial ratios can be calculated simply and accurately.

Backlash analysis of a new planetary gearing with internal gear ring

Due to low carrying capacity and short life of current ring reducer,we proposed a new planetary gearing with internal gear ring,which consisted of two stages.One was an involute planetary drive and the other was an N-type planetary drive with small teeth difference.The kinematic calculation was conducted based on the analysis of structural composition and working principle.Formulas of backlash calculation for the new planetary gearing were derived by using probabilistic theory and the analytical model was created at the same time.Then,main factors that affect the systematic backlash were introduced and the effects of manufacture error,misaligments and roller bearing parameters on the distribution of backlash were presented.The influence of gear backlash on systematic return difference was performed based on the backlash mathematic model proposed.The results show that the backlash is a little large,of which the backlash of bearing takes a greater part than two gearing stages.So we presented some practical methods to reduce the systematic backlash.

The design analyze of new hybrid drive concept

This paper presents the design method of hybrid drive system for the minibus with some limited conditions. The approach of design hybrid drive system is based on the dynamic modeling and simulation of the hybrid minibus with planetary gear system. The main target of the design is to obtain the optimal design with the proper hybrid drive configuration and control for a given set of design constraints. In oder to meet the design target, it＇s necessary to adjust some parameters such as mechanical ratios and parameters of battery pack as well as control by simulation. During simulation the transient operating process can be studied in details with the dynamic model in Matlab/Simulink. The control strategy can be optimized by running the simulation and monitoring the operation of each components： the operating area of internal combustion engine （ICE）, fuel consumption （energy consumption）, the power distribution, the torque and rotary speed of ICE and motor, the operating efficiency of motor, the aheration of battery state of charge （SOC）, current and voltage.

CAD/CAE system for the ring planetary reducer with small tooth number difference

A CAD/CAE system of the ring-type planetary reducer with small tooth number difference is presented. It is a parameterized CAD/CAE system adopting the object-oriented technique and comprising in itself the geometric feature database (including the modules of ring-plates with inner teeth, eccentric shaft modules and output shaft modules), standard component database and material database. In comparison with design by handwork , this computer aided design and analysis system has the advantages of improved quality, shortened design period and reduced cost. The reliability of the system has been verified by a illustrative example.