Use the machining accuracy of the maintenance surface; prevent deformation of the cabinet. 8 Do a good job of maintenance. Frequently check and clear the vent hole of the reducer; pay attention to whether the various gaskets fail and screw leakage during use, and wrap the raw tape or polyvinyl fluoride film on the threaded part; in addition, the input and output must be completed after the repair is completed. The grease on the shaft covering the labyrinth groove blocking the oil return hole is cleaned, so that the lubricating oil can be returned unimpeded to the oil returning pool. 6 Operation 6.1 Reason The 7240 tower crane adopts the joystick linkage desktop operation mode. The lifting mechanism has high, medium and low gears and adopts direct motor speed regulation. The normal operating procedure of the lifting mechanism is to start up and start low speed medium speed high speed medium speed low speed stop reverse scare start low speed medium speed high speed 4 medium speed 4 low speed 4 stop. The slewing mechanism and the trolley luffing mechanism are both high and low, and similar procedures are followed during operation. If the operator is violent and the force is too large, the over-shift phenomenon will occur when the hoisting and slewing mechanism is operated, causing damage to the mechanical components and electrical system, tripping and power failure. In particular, the slewing mechanism, such as the reverse rotation during forward rotation, will generate a large impact torque, causing damage to the mechanism. However, when the tower crane does not have an ultra-high limit, a large impact force is generated on the gear pair of the reducer, causing the gear to collapse, causing the gear pair to be in a disordered state, and generating a large resistance torque on the drive motor for a long time. This can cause damage to the motor. 6.2 Preventive measures In order to avoid the more erroneous operation of the crane operator, several time relays can be added to the control circuits such as the luffing mechanism and the slewing mechanism of the original hoisting mechanism to prevent the misoperation of the various mechanisms. Pay attention to observation and careful operation during work to avoid the above-mentioned fault phenomenon. Communication Address Nanjing Engineering Engineering College Mechanical Experiment Center 21000720 crawler hydraulic excavator charging system fault diagnosis Xuzhou Engineering Machinery Research Institute Shan Zhonghua Wei Dongfeng Yang Weimin Qingdao Municipal Municipal Corporation Wang Zhimin Xuzhou Engineering Machinery Research Institute developed in 2000 stomach 20 , spit thumb, expose the employer, the Portuguese èš´ è ›è‹è‹¡ ,, welcome, the product is in short supply. Its electrical system uses 24 single-wire negative ground. The following is a discussion of the possible failures of the charging system for the user to refer to during the use. The charging system of this type of excavator is composed of an alternator ignition switch voltage regulator charging indicator battery and other components. The generator is the core component of the system. Under normal conditions, the generator's excitation winding has current passing through. When the armature reaches a fixed speed, the generator has a voltage output. The principle of the charging system is that the engine model is Dongfeng Cummins 68 Ding 5.9, matched 28, the rated output current is 45 in, wherein the end is the output end, and the 0+ terminating charging indicator is the grounding end. When the ignition switch is turned on, the current is supplied to the regulator current through the charging indicator 0 regulator + terminal, while the other current passes, the excitation winding, the regulator, the terminal ground, and the charging finger switch, 149. The regulator lights up and provides the excitation current of the generator. When the generator is working normally, the stator winding of the generator generates a phase AC electromotive force. After the bridge full-wave rectification circuit composed of 6 is rectified, the output DC voltage port 8+ charges the battery and supplies power to other electrical equipment. At this time, the excitation current of the generator is supplied by the bridge full-wave rectification circuit composed of 2, 4, 6, 7, 8, and 9. Since the battery is equal, the charging lamp 01 is extinguished and is operated by the above charging system. The principle shows that we can judge whether the charging system is faulty by observing the working state of the charging indicator lamp, and at the same time, cooperate with other detection methods to quickly find out the cause of the failure and repair it. The common faults in use are as follows: The charging indicator does not extinguish the engine start. When the idle speed rises to 2100, the charging indicator still lights up, indicating that the generator does not generate electricity. Here are two ways to determine the fault. At this point, a screwdriver can be used to approach the tail of the motor. If attractive, the excitation winding has a current through it to generate a magnetic field. Otherwise, the motor is decomposed and checked. 2 Use the universal electric blocker to measure the output of the generator 8+ and the grounding resistance of the grounding should be 50, the reverse resistance should be greater than 1, so that it should be characterized by pole tube. If it does not match, the generator has a fault inside. At this time, the regulator can be removed to measure the generator field winding, and its resistance should be 360. If it does not match, it may be a fault such as short circuit between the stator and the ground between the short-circuited phase windings between the stator windings, so as to eliminate it. Close the ignition switch 1 charging indicator light is not bright. There are several types of indicators that may indicate that the lamp is broken, the connecting wire is open, the excitation winding is open, æª, 慊鹂, 厮, and bad. When the charging indicator light is suddenly turned on and off, the engine is in normal operation, that is, it reaches 21; when the charging indicator light is still blinking, the charging current is unstable. At this time, first check whether the generator belt is slipping; if it is excluded, focus on whether the external circuit has poor contact; after troubleshooting, find out if the generator pole tube is open circuit brush slip ring is in contact with the bad generator front and rear end cover bearings are loose. The end cap is loose and so on. The charging indicator light is slightly bright. If the charging indicator light is slightly bright, there is a voltage drop between the + and the battery, but the voltage drop is not very large. This may be due to one or two of the 17, 8, and 9 pole tubes being hit. Wear, should replace the pole tube. After the cause of the fault is identified, appropriate measures can be taken for repair to quickly resume production. Communication address Xuzhou Engineering Machinery Research Institute No. 50, Tongshan Road, Xuzhou City, using Ingersoll Rand, 500 open-air hydraulic drilling rigs to improve the consolidation of grouting holes in the treatment of the Heihe dam foundation, due to design changes, temporarily increased solid The workload of the junction grouting hole, due to the narrow space of the project, can be completed even if 1820 geological drilling rigs are put into operation at the same time. In order to speed up the construction schedule, we used the Ingersoll Rand 1500, a short, hydraulic drilling rig to drill the consolidation grouting holes. The drilling speed of the machine can reach 0.5mmill, which is 80100 times of the drilling speed of the geological rig. It takes only about a month to complete the task with the platform 5000 open-air drilling rig, which can save a lot of manpower and material resources required for power supply and water supply and rig lifting and drilling work, and can also retrieve the construction period of more than two months. However, when the 15000 surface drilling rig is constructed by conventional methods, the requirements for the hole inclination are difficult to ensure for the stratum with joint development and inclined rock formation. The Heihe strata are separated by white quartzite and chlorite, and the rock dip angle is large. When using the 5000 deep-pit drilling rig to drill the hole depth of 1, the deflection at the bottom is about 0.71.5, but the consolidation grouting hole is re-examined, and some measures are taken. Expected effect, finished on time Chain Sling Hook,Chain Block Hook,3 Leg Chain Sling,4 Leg Chain Guangdong Gongyou Lift Slings Machinery CO.,LTD , https://www.workmatehoist.com