ZL50型装载机变矩器温度升高的原因分析及检修

文章主要就ZL50型装载机变矩器温度升高的原因从四个方面进行了分析和探讨。     

980S型装载机的变速操纵阀

本文介绍引进ＣＡＴ９８０Ｓ型装载机变速器及变矩器液压控制系统的构成、工作原理,并对该变速器系统中液压控制元件－变速阀的保护功能和自动回复空挡位置等功能及变矩器系统进行了较详细的分析。     

装载机液力变矩器的故障与维修

液力变矩器在工程机械中有着广泛的应用,但变矩器的拆装与维修比较困难。本文以双导轮综合式液力变矩器为例,介绍液力变矩器的工作原理,分析变矩器工作过程中的常见故障现象、原因和诊断维修方法。１双导轮综合式变矩器的工作原理该变矩器主要由泵轮、涡轮、第一导轮、第二导轮及导轮座等组成。工作过程中,液压油自变速器壳底部通过滤网被油泵吸人,然后流向泵轮。柴油机的动力通过相啮合的齿轮传给泵轮,泵轮的旋转将进入其内部的液压油压入涡轮,冲击涡轮叶片,使涡轮旋转,动力由涡轮轴输出,从涡轮出来的液压油,一部分通过变矩器出…     

装载机故障及排除方法实例

介绍了装载机易发生的两种故障，即变速器油面升高或降低和工作泵轴端油封失效引起装载机产生的故障，针对其产生的原因，提出了简明的判别方法及修复措施。     

K—702型装载机变矩器故障与排除

1前言1992年我处购进了两台俄罗斯产K－702装载机。该机变矩器是四元件单级三相变短器，可根据不同的工况实现两个导轮固定；或一个导轮固定，另一个导轮空转；以及两个导轮都空转等三种工作状态。变矩器内带有自动锁紧离合器，可以将泵轮和涡轮刚性地连接在一起，变成机械传动。因此，该变矩器在较大的传动比范围内效率较高。2变矩器工作原理柴油机将动力传递给变矩器泵轮，变矩器内的锁紧离合器压盘和主动磨擦片既能与泵轮相连一起旋转，又能轴向移动压紧从动摩擦片，实现自锁。涡轮通过内花键与涡轮轴相连，将动力传递给变速器。涡轮轴…     

燃油发动机冷却系的重要性及其影响因素

简述了发动机冷却系的重要性，分析了冷却系冷却不足或冷却过度对发动机产生的不良影响，论述了影响发动机冷却系的三个主要因素，指出三者应比例协调，才能发挥最佳冷却效果。     

发动机润滑油的现状和发展过程

简述了汽油机油的技术发展过程和我国内燃机油的使用现状。通过与美国API标准的对比，指出我国润滑油普遍存在档次低和发动机的引进与发展不匹配等问题，同时也为工程机械用户提供了一些理论性建议。     

某发动机试验室循环水系统设计

结合工程实例,就柴油发动机试验所采用的循环水系统及其原理作了分析,同时对循环水系统设计进行了全面阐述,通过分析计算保证有足够的冷却水流过试验设备,达到要求的冷却能力。     

Performance and emission characteristics of a diesel engine fuelled by neem oil blended with alcohols

Fuel crisis and environmental concerns have led researchers to look for alternative fuels of bio-origin sources such as vegetable oils, which can be produced from forests and oil-bearing biomass materials. Vegetable oils have energy content comparable to that of diesel fuel. Straight vegetable oils posed several operational problems and durability problems when subjected to long-term usage in compression ignition engine. These problems are attributed to higher viscosity and lower volatility. In this study, performance and emission parameters of a diesel engine operating on neem oil and its blends of 5, 10, 15 and 20?vol% with ethanol, 1-propanol, 1-butanol and 1-pentanol are evaluated and compared with diesel operation. The results indicate that the brake thermal efficiency is improved with the use of neem oil–alcohol blends with respect to those of neat neem oil. The smoke intensity, CO and HC emissions with neem oil–alcohol blends are observed to be lower with respect to those of neat neem oil at higher loads. The NO _x emission is very slightly reduced with the use of neem oil–alcohol blends except for the neem oil–ethanol blend compared with that of neat neem oil.     

Energy and exergy analysis of a CI engine using tyre pyrolysis oil blends with diesel

Tyre pyrolysis oil (TPO) blend with diesel can be used as an alternate fuel. Tests have been carried out to analyse the energy and exergy characteristics of diesel engine fuelled by B10, B20 and B30 blend of TPO with diesel fuel. TPO was derived from waste automobile tyres through vacuum pyrolysis process (batch type). In this paper, the brake thermal efficiencies of TPO of different blends (10%, 20% and 30%) are compared with the pure diesel and discussed. Further, exergy and energy values of TPO–diesel with different blends are analysed.     

Performance of a twin cylinder dual-fuel diesel engine using blends of neat Karanja oil and producer gas

In the present study, performance and emission analysis are done in a twin cylinder four-stroke dual-fuel diesel engine in two cases of operation. In the first case, the engine is tested using diesel, K10 (10% neat oil+90% diesel) and K20 (20% neat oil+80% diesel) in single mode and in the dual-fuel mode with an optimum producer gas flow rate of 21.49 kg/h under different load conditions. In the second case, the engine is tested using the same test fuels in the dual-fuel mode at different gas flow rates under a constant load of 10 kW. The study reveals that the dual-fuel operation of all test fuels shows a lower engine performance and better control of smoke and oxide of nitrogen emission compared with their single-mode operation under all load conditions. Whereas other emission parameters such as carbon monoxide, carbon dioxide and hydrocarbon are at a higher level.     

Modelling and simulation of a bio-fuelled conventional engine

In the present work, a simulation model based on two different zones of combustion in compression ignition (CI) engines has been modified to predict the performance of a four-stroke CI engine. The modified model for the calculation of closed cycle of a four-stroke diesel engine is presented and applied for its operation with vegetable oil (Jatropha), which is considered as promising bio-fuels now a days. For the local temperature and cylinder pressure calculations, the mass and state equations are applied in each zone. The effect of fuel injection pressure and advance angle of fuel injection point on the brake thermal efficiency, brake-specific fuel consumption and nitric oxide emission has been analysed. The results from a computer program are compared and verified with the corresponding measurements from an experimental investigation conducted on the test bed. A good synchronisation is observed between the model's prediction and the available theoretical and experimental results. Engineering equation solver has been used as the programming input to the model.     

Experimental investigation of the influence of isobutanol addition on engine performance and emissions of a direct ignition diesel engine fuelled by biodiesel blends derived from waste vegetable oil

Biodiesel has become one of the potential alternative sources to replace diesel. Some of the limitations of biodiesel include high NO _x , poor atomization, poor oxidation stability, cold-flow problems, long-term storage problems, etc. Various strategies were discussed to overcome the limitations of biodiesels. Recent research is on effects of fuel additives or fuel composition modification to reformulate the fuel properties. This article is aimed at presenting the experimental investigation of the effects of isobutanol additive on the engine performance and emission characteristics of biodiesel blends derived from waste vegetable oils. The experimental investigation was conducted on a direct injection four-stroke diesel engine with different blends, B10, B20, B30, B10 (10% ISB), B20 (10% ISB), B30 (10% ISB), B10 (20% ISB), B20 (20% ISB) and B30 (20% ISB), and engine performance and emission characteristics are evaluated and discussed.     

Experimental analysis of Deccan hemp oil as a new energy feedstock for compression ignition engine

This study investigates the biodiesel from Deccan hemp oil and its blends for the purpose of fuelling diesel engine. The performance and emission characteristics of Deccan hemp biodiesel are estimated and compared with diesel fuel. The experimental investigations are carried out with different blends of Deccan hemp biodiesel. Results show that brake thermal efficiency is improved significantly by 4.15% with 50 BDH when compared with diesel fuel. The Deccan hemp biodiesel reduces NO_x, HC and CO emission along with a marginal increase in CO₂ and smoke emissions with an increase in the biodiesel proportion in the diesel fuel. The improvement in heat release rates shows an increase in the combustion rate with different percentage blends of Deccan hemp biodiesel. From the engine test results, it has been established that 30–50 BDH of Deccan hemp biodiesel can be substituted for diesel.     

GPS消防车辆监控系统通信方式新探

介绍了消防 GPS车辆监控系统的通信方式 ,着重分析了集群通信技术在车辆监控系统中的应用 ,包括系统组成、信道利用方式、呼叫方式、同步方式、数据传输格式等内容。