Judging from the development of construction machinery in recent years, the development of excavators is relatively fast, and is already the most important construction machinery in engineering construction. However, you may encounter some problems in daily construction operations, and do not know how to deal with them. The following will take you to learn together!
1. Common failures of excavators
1. Jump
(1) Wear of the variable speed transmission mechanism The W4-60 excavator uses a mechanical shifting transmission mechanism. This transmission mechanism relies on the sliding gear sleeve to move axially on the fixed gear sleeve and is connected to the driven gears of each gear. Engage to achieve the shift. During frequent gear shifts, the end faces of the gear teeth of the above-mentioned meshing gears are easily ground into a tapered shape, resulting in a decrease in meshing performance and resulting in "jumping".
(2) The performance of the self-locking mechanism is reduced. In order to prevent the transmission from "jumping", this type of excavator is located in the hole of the box cover above the shift shaft of the shift gears II, III, IV, and V of the transmission and in the shift fork of the I, reverse gear There are steel balls and springs that are self-locking. When the elasticity of the self-locking spring is weakened or broken, the self-locking performance of the self-locking mechanism will decrease until it disappears, causing the transmission to "jump". At the same time, if the groove on the positioning steel ball or the fork shaft is worn, it can also cause the transmission to "jump".
(3) Improper adjustment of the shifting device The transmission of this type of excavator adopts the method of mechanical manual shifting. If the shift lever, vertical axis, horizontal axis and vertical fixing screws are loose, the transmission may "jump".
(4) Sudden change in external load Due to the working nature of the excavator and the design of the machine itself, sudden changes in external load can also cause its transmission to "jump". When the road surface is uneven, the machine is driving downhill or the driving route is improper, the external load suddenly changes, this sudden change of load will act on the gear meshing gear of the transmission through the wheel and the transmission shaft, so that the gear meshes the gear It is disengaged due to the axial thrust, causing the transmission to "jump". (5) Improper operation method When the excavator is driving on a slope (especially when driving downhill), improper operation will also cause the transmission to "jump".
2. Preventive measures
(1) Operate strictly in accordance with the operating regulations and driving guidelines, and try to avoid "beating" when shifting gears to reduce the wear of the gear pair.
(2) Strictly implement the maintenance system and strengthen the maintenance of the shifting device. When the shifter rod system is improperly connected, it should be adjusted in time to ensure good performance of the shifter.
(3) Pay attention to the repair and maintenance of the self-locking mechanism. The positioning steel balls, springs and fork shafts with reduced positioning effect or loss of positioning efficiency should be repaired or replaced in time, so that the self-locking performance of the self-locking mechanism is in good condition. .
(4) When assembling the transmission, strictly follow the operating procedures to ensure that the transmission parts are adjusted correctly and tightly. When driving downhill on a large road, the driver should strictly follow the downhill action and must not violate the rules.
2. Emergency handling method of excavator
During the driving process of the excavator, if the transmission "jumps", the machine should be stopped in time (or continue to drive), and then find the cause and eliminate the fault. The specific method is:
(1) When "jumping" occurs when driving on a flat road, the machine can be stopped according to the normal stopping method, and the cause is carefully found to eliminate the fault.
(2) When "upshifting" occurs when driving uphill, the gear position can be set to the low-speed position or Ⅰ gear position, and the standby device stops when it reaches the top of the slope to eliminate the fault; if the gear reduction is not successful or appears again " When "jumping gear", stop according to the action and requirements of the ramp stop, and then eliminate the fault.
(3) When "jumping" occurs when driving on a downhill slope, the gear should be positioned at a high-speed position according to the action of upshifting or "rush grab" (emergency gear reduction) measures should be taken. After the standby device travels to the bottom of the slope Then stop the machine to check and eliminate the fault; if "shift up" or "grabbing" is unsuccessful or if "jumping" occurs again (at this time in neutral), the driver can control the engine speed at medium speed (to prevent the engine from stalling) , Use the "point brake" method to make the machine slide to the bottom of the slope, and then eliminate the fault. If "add gear", "snatch gear" is unsuccessful or "jump gear" appears again (at this time in neutral), and the machine is on a downhill slope (at this time, the machine will move to the bottom of the slope at a very fast speed) "Dive"), should quickly stop according to the action and requirements of downhill shutdown, and then deduct the fault.
