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Slewing Bearings
Slewing
bearings are large- size bearings, which can carry combined loads: axial, radial load and
tilting moment. They are usually equipped with fixing bolt holes, Internal or external
gear, lubrication holes and sealing elements, consequently machinery structure can be made
compact, guided rotary convenient, mounting and maintenance easy.
Available slewing
bearings are: bearings with internal gear, external gear, external gear or non-gear,
four-point contact ball bearings, double row angular contact ball bearings, cross
cylindrical roller bearings and three row combined cylindrical roller bearings, among
which four-point contact ball bearings have the higher static load carrying capacity while
cross cylindrical roller bearings have the higher dynamic load carrying capacity. The
pre-interference of cross-tapered roller bearings provides higher supporting rigidly and
better rotary accuracy. with wider width and different raceways being capable of carrying
any direction loads, three row combined cylindrical roller bearings have the same loads
therefore compact machinery structure can be obtained. This is a kind of heavy-duty
slewing bearings.
The typical
applications of the slewing bearings: lift and transport machinery, excavation machinery,
building machinery, harbor machinery, cargo lifting machinery on ships, and even
high-precision radar antenna mounts and missile launching pads.
The Code Expressions of Slewing Bearings
In this
catalogue, there are two kinds of code expressions of LYC bearings
1. The code
expression shown in the bore diameter and structure of bearings there are two
parts, basic-code and suffix. The expressions of type and structure of the basic-code are
as follows:
Type
and Structure |
Gear
Form |
Non-Gear |
External-Gear |
Internal-Gear |
Four-point contact
ball bearings |
78000 |
178000 |
278000 |
Double row angular
contact ball bearings |
578000 |
678000 |
778000 |
Cross cylindrical
roller bearings |
79000 |
179000 |
279000 |
Cross tapered
roller bearings |
579000 |
679000 |
779000 |
Three row combined
cylindrical roller bearings |
539000 |
639000 |
739000 |
In the suffixed
symbols, G shows that the bearing ring is made of 5CrMnMo steel. While G2 shows the ring
is made of 50Mn.
LYC Slew Ring Catalog
2. The code
expression shown in pitch circle diameter of rolling elements, rolling element diameter,
form of gear, structure of raceway and etc.
X
X X . X X . X X X X
X -----------------------------
Pitch circle diameter of rolling elements (mm)
X ----------------------------- Rolling element diameter or mean diameter (mm)
X ------------------ Engaged gear-form: 0-non-gear
1-less
modular external gear
2-more modular external gear
3-less modular internal gear
4-more modular internal gear
X X ------------Structure of raceway:
1-four-point
contact ball bearing or cross-cylindrical roller bearing
2-double row
self-aligning ball bearing or cross-tapered roller
bearing
3-three row combined
cylindrical roller bearing
X X X X-- Rolling element form:
0-ball, 1-roller
LYC
Slew
Ring Catalog
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