自动搅拌车的液压系统的可靠性是用主机液压系统在额定工况正常操纵下，无故障使用时间来表示的。显然，无故障使用时间越长，可靠性越好。下面来讲讲自动搅拌车液压系统故障原因分析。

The reliability of the hydraulic system of the automatic mixer truck is expressed by the trouble free service time of the host hydraulic system under normal operation under rated working conditions. Obviously, the longer the trouble free service time is, the better the reliability is. Now let's talk about the cause analysis of the hydraulic system failure of the automatic mixer.

（1）空载下，转罐转速可达到设计要求，而装满料以后很难起动，即使在发动机大转速下转罐转速也很低；（2）液压油散马达的进油胶管出现多台爆管故障；（3）转罐马达的故障率非常高，多台出现马达内部卡死或轴端密封损坏向外串油。

(1) Under no load, the rotating speed of the can can meet the design requirements, but it is difficult to start when the material is full, even under high engine speed, the rotating speed of the can is very low; (2) The oil inlet hose of the hydraulic oil dispersion motor has multiple tube explosion failures; (3) The failure rate of the rotary drum motor is very high, and several motors are stuck internally or the shaft end seal is damaged and oil flows outward.

从原理上来看，液压系统为开式负载敏感开芯回路，通过安装在发动机上的齿轮泵持续向换向阀供油，由先导控制阀作为总开关，通过控制电磁换向阀的翘板开关实现转罐马达的正转与反转。换向阀的回油分两路回油箱：一路通过节流阀回油箱，另一路驱动油散马达，为其他系统的回油进行散热。

In principle, the hydraulic system is an open load sensing open core circuit. The gear pump installed on the engine continuously supplies oil to the reversing valve. The pilot control valve acts as the main switch, and the rocker switch of the solenoid reversing valve controls the forward and reverse rotation of the rotary tank motor. The return oil of the reversing valve returns to the oil tank in two ways: one returns to the oil tank through the throttle valve, and the other drives the oil dispersion motor to dissipate heat for the return oil of other systems.

通过故障情况与原理对比分析，认为换向阀的回油通过节流阀的阀口来控制油散马达的工作转速，且节流阀阀口是在出厂前根据发动机怠速调节油散马达转速的，一旦节流阀阀口固定，通油能力就会被限制在一定的范围内，然而换向阀的输出流量与发动机的转速成正比关系。

Through the comparative analysis of fault conditions and principles, it is believed that the return oil of the reversing valve controls the working speed of the oil dispersion motor through the throttle valve port, and the throttle valve port regulates the speed of the oil dispersion motor according to the engine idle speed before leaving the factory. Once the throttle valve port is fixed, the oil flow capacity will be limited to a certain range. However, the output flow of the reversing valve is proportional to the engine speed.

在发动机高速运转时，换向阀T口油液无法快速回到油箱，造成油散马达的进油管处压力过高，超过胶管承受的压力，所以爆管现象时有发生。因无法得到更详细的技术参数与资料，重载转速慢及马达故障率高是否有直接关联，通过现场查看实车的系统现状及使用过程工况，从使用工况来分析故障原因。

When the engine is running at high speed, the oil at port T of the reversing valve cannot return to the oil tank quickly, which causes the pressure at the oil inlet pipe of the oil dispersion motor to be too high, which exceeds the pressure borne by the rubber tube. Therefore, tube explosion occurs frequently. Since more detailed technical parameters and data can not be obtained, whether there is a direct correlation between slow heavy load speed and high motor failure rate, we can analyze the cause of the failure from the operating conditions through on-site inspection of the actual vehicle's system status and operating conditions.

从现场的管路情况看到，吸油管过长过细，且齿轮泵的位置高于油箱吸油口的位置，经理论计算齿轮泵吸油管液压油大流速达到4m/s，远超过设计标准。同时，齿轮泵本身的自吸能力差，在高转速时吸油管内产生负压，齿轮泵内部吸油不足加速磨损，容积效率快速下降，导致转罐在重载情况下转速下降明显。

It can be seen from the on-site pipeline that the oil suction pipe is too long and thin, and the position of the gear pump is higher than the position of the oil suction port of the oil tank. Through theoretical calculation, the large flow rate of hydraulic oil in the gear pump oil suction pipe reaches 4m/s, far exceeding the design standard. At the same time, the self suction capacity of the gear pump itself is poor, and negative pressure is generated in the oil suction pipe at high speed. The insufficient oil suction inside the gear pump accelerates wear, and the volumetric efficiency drops rapidly, resulting in a significant drop in the speed of the rotary tank under heavy load.

自动搅拌车一般从搅拌站装上搅拌好的混凝土，转运工地使用；而自动搅拌车一般是在工地附近，具有自装卸、配料与自搅拌功能，减少长距离运输且省工的特点。更多相关内容就来我们网站http://www.jfhntjbc.com咨询吧！

The automatic mixer truck generally loads the mixed concrete from the mixing plant and transfers it to the construction site for use; The automatic mixer is generally located near the construction site, with self loading and unloading, batching and self mixing functions, reducing long-distance transportation and saving labor. More relevant content will come to our website http://www.jfhntjbc.com Consult!