Slewing bearing is one support composition loads which is developed step by step during the end of 1940s (axial loads, radial loads and titling moment) large scale bearing. Slewing bearing contains mounting holes, inner ring or outer ring, spacer, isolation holder, grease hole and seals, therefore, it makes engineer designs compact structure, to easy operate and maintenance convenient.
Slewing bearing has no teeth rings, outer teeth rings and inner teeth rings’ single row ball type, double row ball type, double-line ball type, single row cross roller type, three row roller type, ball and roller combination series, among which, the single row cross roller slewing bearing is the most earliest designed. Especially to say, the single row four point ball contact type was bloomed about 85s, then this type slewing bearings instead of bearings, besides, slewing bearing material is much more to choose, such as 50mm is high tension, moderate price, 42CrMo is high strength, more flexibility, but price is higher, S48C product feature is the middle one, stainless slewing bearing is widely used too, but the biggest disadvantage is that it cannot be quenched, cannot bear high loads.
To be back, as one example, let’s briefly introduce the excavator slewing bearing’s operation principle.
The excavator slewing bearing device is composed of a turntable, a slewing bearing and a slewing mechanism, the outer ring of the slewing bearing is connect to turntable with high strength bolts (it divides three stages forcing the bolts pre-tightening), inner race with teeth and chassis connected by bolts, inner race and outer race has rolling body, the rolling body usually divided into ball type and column type, according to different working condition to choose. The vertical load, horizontal load and overturning moment of the excavator device on the turntable passed to the chassis through the outer race, rolling body and inner race. The housing of the rotary mechanism is fixed on the turntable and messed with the gear ring on the inner race of the slewing bearing through the pinion. When you adjust clearance especially important is the first installation, specific details please refer to our clearances technical of slewing bearing information. The pinion can rotate around its own axis and revolve around the centreline of the turntable. Once the rotary mechanism works, the turntable rotates relative to the chassis. Due to the poor working condition of the excavator, regularly maintain could be added the use life of the excavator to a certain extent.