针对目前应用于有机朗肯循环(ORC)的容积型小容量膨胀机结构复杂、难以应用推广的现状,提出了一种新型球形滚珠膨胀机.其组合了滚动转子式膨胀机和往复活塞式膨胀机的部分特征及优点,结构简单、零件数少、制作方便、运动平衡性好.介绍了球形滚珠膨胀机的工作原理和运行过程以及部分主要零件的设计,并在此基础上设计了一种区别于常规进气结构的优化方案,取消了进气阀,减小了流动损失和阀门振动噪声.针对某一工况设计了膨胀机尺寸,并进行了润滑设计和泄漏分析以及容积效率估算.
Sheet-bulk metal forming(SBMF)is a promising process for manufacturing complex sheet components with func-tional elements.In this study,the entire forming process for a typical thin-walled component with external gearing is investigated,including sheet fo
A decrease in the weight of aerospace vehicles,large ships,weapons,and high-speed trains will increase the demand for wide-width magnesium alloy plates and their composite parts to replace steel and plastic.An investigation was conducted to study the vari
The current research of the Q-P and Q-P-T process has been focused on controlling the heating temperature and holding time,or adding alloy elements into the steel to induce precipitation strengthening and improve the strength and plasticity of the steel.I
Joining metal to plastic can lighten weight of products to reduce energy consumption.However,it is difficult to achieve high-strength welding between metal and plastic.To address this problem,the methods of surface texture pretreatment and laser irradiati
Most of traditional traveling wave piezoelectric transducers are driven by two phase different excitation signals,lead-ing to a complex control system and seriously limiting their applications in industry.To overcome these issues,a novel traveling wave sa
The cast aluminum beam is a key structure for carrying the body-hung traction motor of a high-speed train;its fatigue property is fundamental for predicting the residual life and service mileage of the structure.To characterize the struc-tural fatigue pro
滚动轴承出现局部剥落、点蚀等故障时,会产生周期性的振动冲击信号,通常对此信号进行分析即可诊断出故障的严重程度以及出现的位置.但是,设备工作时往往伴随着较大的噪声,因此冲击信号,尤其是早期故障的振动冲击信号,很容易被噪声淹没.针对此问题,本文提出一种基于恒Q变换与二进制能量权重的CQTBEW算法,首先将振动冲击信号进行恒Q变换分析,获得时频谱矩阵;其次对矩阵进行频率分段处理,在时间轴设置滑移窗口,筛选局部极值并二值化时频谱,向时域叠加获得能量时域信号,进行功率谱分析诊断获得特征频率;最后进行仿真信号与实验信
Load-sensing steering systems for articulated loaders are prone to large pressure shocks and oscillations during steering operations,affecting the system stability.An optimized structure of the redirector with bypass damping is proposed to improve this ph
This study proposes and experimentally validates an optimal integrated system to control the automotive continu-ously variable transmission(CVT)by Model Predictive Control(MPC)to achieve its expected transmission efficiency range.The control system framew