Excavator slewing mechanism of sound structure improvement

Excavator slewing mechanism of sound structure improvement - 2019 11 - 16 fault phenomenon on SW240E type excavator maintenance, found that more than one type excavator do rotary motion, the slewing mechanism are issued a clear sound, especially rotary stop instantly, a clear voice. When the excavator model from the production line had no such problem, the excavator is in the use of 500 ~ 600 h after the above problems. Cause analysis under the excavator slewing mechanism is mainly composed of frame, frame, rotary rolling plate, fixed bolts and rotary motor assembly and so on, as shown in figure. Excavator on the frame and lower frame through rotary rolling plate connection, rotary rolling plate outer ring, inner ring respectively through the bolt on the excavator with frame and out of the car frame. Between rotary rolling disc ring and outer ring raceway and ball, can make the relative rotation between inner and outer ring. Rolling disc ring has a large ring gear, digger rotary motor assembly frame installed on active pinion and ring gear meshing. Excavator do rotary motion, rotary motor assembly drive pinion rotating actively, active pinion by big gear ring turns on the frame, so as to realize the rotary motion of excavator get on the bus. According to preliminary analysis structure of excavator, the excavator slewing mechanism sound may have the following three reasons: one is the rotary motor fault; Active pinion rotary motor assembly and rotary roll drive ring gear meshing when there is a big gap; Three is rotary rolling plate rolling way, ball bearing wear. Troubleshooting in order to identify the reasons for turning sound, we select one that type excavator to troubleshoot: first, the overall excavator rotary motor assembly replacement ChengXinPin, sound is still there. This rule out the possibility of rotary motor and reducer is fault. Secondly, testing the new rotary motor assembly initiative between pinion and rotary roll drive gear ring gear side clearance of 1. 7 mm, slightly larger than the clearance value ( Standard value is 0. 4 to 0. 85毫米) 。 Again, the excavator slewing rolling tray. After changing new rotary rolling plate, sound disappear, but use after period of time sounded again, and found in rotary rolling plate groove under the existing metal grinding after spalling of iron powder. Test rolling plate, hardness of the inner and outer raceway, ball in a reasonable range, check the heat treatment process conforms to the specification. Finally, the installation of rotary rolling plate of upper and lower frame, measured, and out of the car in the plane of the rotary rolling plate installed planeness for 2 ~ 3 mm, it rolled disk installed flat flatness technical requirements should be less than 1 mm, the value is significantly more than design standard. In addition, the rotary rolling plate have loose phenomenon. Our inspection on the batch of excavator, this batch of excavators are varying degrees of above problems. Method according to the result of troubleshooting, the fault phenomenon for active pinion rotary motor and rotary roll drive between ring gear backlash is too large. To this end, we to improve the gear side clearance size, specific improvement measures include the following three aspects: one is increasing the thickness of the rotary rolling drive gear ring gear, decrease the rotary roller drive gear ring and rotary motor pinion drive pay the backlash, make the clearance by 1. 7 mm decreases to zero. 4 to 0. 85毫米; 2 it is between the rotary rolling plate and turntable with positioning pins, in order to make sure the parts after long time use will not shift as the radial force; Three is the upper and lower frame rotary rolling plate installation surface flatness control within 1 mm. Above improvement measures, the number of excavator slewing rolling disc problem won't happen again. The troubleshooting, due to the original excavators rotary rolling plate locating pin, as the growth of the use of time, cause the rotary rolling plate is loose, rotary motor assembly initiative between pinion and rotary roll drive gear ring gear side clearance, cause the excavator use after a period of time, momentary obvious slewing brake to stop banging sound. Off and on, rotary rolling plate mounting surface flatness, after long-term use of the rotary rolling plate groove and ball bearing severe wear. （ Source: web)