Publish Time: 2022-12-01 Origin: Site
The slewing bearing is mainly composed of outer ring and inner ring, rolling elements, cages, sealing rings, etc. Since different parts have special functions in practical application, there are different considerations in the construction and selection of materials.
What are the reasons of premature failure for the slewing bearing due to teeth broken?
What properties materials be used in slewing bearings?
What do I have to consider if I repair the slewing bearing myself?
From the analysis of the data available to us, it appears that most 20-22-ton excavators at home and abroad use slewing bearings with a module of 10mm (or diameter division H2.5), heat treatment and accuracy are basically the same, excavators generally use the standard tooth height and standard engagement angle. The permissible circumferential force P of the slewing bearing can be calculated as follows:
P=Kz*m*b/78 (tonnes) where Kz=(z/150)^(±0.09) is the outer tooth. the inner tooth is -z Δ number of teeth m Δ module mmb Δtooth width mm width b=80; Number of teeth z=90~110; and for internal engagement, the permissible circumferential force of the gear is:
p=(90~110/150)^(-0.09)*10*80/78=10.74~10.55 (tonnes)
It is apparent that the permissible circumferential force of the gear can meet the load requirements of the slewing bearing gearbox of the barrel excavator, but the early tooth fracture rate of the slewing bearing on some models of this stage is as high as 2%, and most other models do not have a gearbox. This phenomenon occurs.
In general, the rolling elements of the rotary joint are made of carbon-chromium bearing steel, which is hardened in the whole. The slewing bearing ring is made of surface hardened steel. If the user has no special requirements, it is generally made of 50Mn steel, but sometimes to meet the host's requirements in some special applications, other surface qualities can also be selected according to the user's specific conditions. Hardened steel, such as 42CrMo, 5CrMnMo etc.
In general, the quality guarantee period of the slewing bearing is calculated from the date of delivery and the quality assurance of the slewing bearing ends after 12 months. After some users have purchased the slewing bearing due to equipment or other reasons, the slewing bearing must be placed for several months before it is activated. As soon as the slewing bearing fails at the time of warranty, there will be maintenance costs for the equipment. For example, can the slewing bearing be repaired by itself? What problems do you need to pay attention to when repairing yourself?
In fact, the construction of the slewing bearing is very simple. The main thing is to place the balls in the two circles. It is not impossible to repair the slewing bearing yourself. If it is a simple damage, for example, if the nylon spacer inside is broken, disassemble it and reinstall it.
If you want more information about the slewing bearing, please contact LYXQL Slewing Bearing Co., Ltd., they will be happy to help you.
LYXQL Slewing Bearing Co., Ltd. founded in 2003, is the leader manufacturer of large size slewing bearings in China. As one of the national key high-tech enterprises, LYXQL became the GEM listing company successfully on July 13, 2020 (stock code 300850).