计算多构件机构传速比的传动单元法

在分析多构件机构传统的传速比计算公式基础上 ,借鉴有限元法思想 ,提出了传动单元和传动节点的概念。经过将多构件机构中的传动形式归纳为两种传动单元 ,推导出用传动单元法计算多构件机构传速比的通用公式。并以火炮自动机中常见的多构件机构为计算实例 ,阐述了用传动单元法计算多构件机构传速比的方法和步骤。

自动武器运动计算中传速比的曲线拟合

本文介绍一种在自动武器计算中能较简便的使 k=f(α,β,l…)变为 k=F(x)的函数关系的方法,即用最小二乘法对已知的 k 随 x 变化的表格函数进行曲线拟合,从而近似地找出一个可求导的 k=F(x)函数表达式来。

2N—Z型少齿差传动计算分析

本文以N型和NN型机构为基础,设计了一种有两个内齿圈和一个行星齿轮的2 N—Z型少齿差传动机构(见结构示意图)。并以参考文献为基础,对2 N—Z型传动进行了传动比计算和几何计算分析,其最佳传动比范围为i=45～75。计算结果较为理想,并经生产检验,证明实用可靠。

可控后坐能量的杠杆式半自由枪机动力学仿真

针对枪机后坐式的武器难以实现枪机能量的调节,无法同时满足恶劣环境下的可靠性和普通环境下的射击精度的问题,设计了一种能量可控的半自由枪机结构.该结构以杠杆作为枪机的加速机构,通过可控能量调节装置调节加速机构的传速比,从而调节枪机的后坐动能.推导出不同传速比时后坐能量比值的理论公式,应用多刚体动力学仿真软件,对相应情况做了运动和动力学仿真,理论和仿真能很好地吻合.结果表明,该能量可控式结构应用在半自由枪机自动方式上可实现对枪机后坐能量大小的控制,可以更好地提升武器的战场适应能力.

自整角机工艺误差的修正方法

在系统阐述自整角机工作原理的基础上 ,详细论述了在航空炮塔随动系统中 ,如何利用现有的自整角机来减小随动系统的误差以及消除假协调 ,从而使随动系统满足技战术指标。

第二类拉格朗日方程建模在自动武器上的应用

以高等动力学理论为基础,采用第二类拉格朗日方程建模方法,推导出典型二自由度机构运动微分方程,给出用该方法推导的某航空机关炮二自由度运动微分方程,并对模拟结果进行了分析.

关于火炮自动机后座反面问题计算的若干问题

本文讨论火炮自动机后座反面问题计算中的传速比K、效率η、导数dK/dX的计算方法,以及当K=0时,比值K /η对于后座阻力R曲线的影响等问题。

Propagation velocity measurement for flame of gas explosion in horizontal tube

In coal industry,gas explosion accidents emerge constantly,causing enormous casualties and poorer material property.In the course of studying gas exploding mechanism,the propagation velocity of the flame wave front is one of the most important factors.A set of flame velocity measuring system was designed according to the horizontal pipelined experimental facility of North University of China to study the effects of the quantity and blockage ratio of the circle ring obstacle on the flame propagation velocity in the inclosed tube.The research results show that the obstacle has obviously accelerating effect on the flame wave of gas explosion With the increase of quantity and blockage ratio of the obstacle,the flame accelerating effect becomes more obvious and the flame accelerating persistence is intenser,of which the effect of the quantity of the obstacle on the flame accelerating persistence is larger,but the effect of the blockage ratio of the obstacle on the flame accelerating persistenceis not obvious.

Optimum Calculation of Partial Transmission Ratios of Mechanical Driven Systems Using a V-belt and a Two-Step Bevel Helical Gearbox

This paper introduces a new study on the optimum calculation of partial transmission ratios of mechanical drive system using a V-belt and two-step bevel helical gearbox for getting minimum size of the system. In the paper, based on moment equilibrium condition of a mechanic system including V-belt and a two-gear-unit of the gearbox, models for optimum calculation of the partial ratios of the V-belt and the gearbox were proposed. As the models are explicit, the partial ratios can be calculated accurately and simply.

Space-time Block Codes Based on Quasi-Orthogonal Designs

A new space-time block codes based on quasi-orthogonal designs are put forward. First the channel model is formulated. Then the connection between orthogonal /quasi-orthogonal designs and space-time block codes is explored. Finally we make simulations for the transmission of 4 bits/s/Hz and 6 bits/s/Hz using eight transmit antennas using the rate 3/4 quasi-orthogonal space-time block code and the rate 1/2 full-diversity orthogonal space-time block code. Simulation results show that full transmission rate is more important for very low signal noise ratio (SNR) and high bit error probability (BEP), while full diversity is more important for very high SNR and low BEP.

输弹进弹纵横谈(二)

弹链式供弹的输弹机构 弹链式输弹,依次移动带有枪弹弹链的链节,使枪弹移至进弹口(或取弹口)的位置,然后,由进弹机构推弹(或先取弹再推弹)进膛。输弹机构主要由弹链、受弹器和拨弹机构等几部分组成。 弹链 有规则地抱持枪弹的链式容弹具。弹链有多种形式(弹链分类请见《轻兵器》2002年第5期“读者点登”——《浅谈弹链》一文)。