The common structural forms of slewing bearings are single-row, double-row four-point contact ball slewing bearings, double-row angular contact thrust ball slewing bearings, crossed cylindrical roller and crossed tapered roller slewing bearings, three-row cylindrical roller slewing bearings, balls Different structural forms such as column hybrid slewing bearing. Although the structure is different, the materials used are similar, and the material of the slewing bearing directly determines the performance and service life of the bearing. Today, the editor will take everyone to understand what materials are used for the slewing bearings.
1. Material for ferrule and rolling element
Because the bearing should have the characteristics of long life, high precision, low heat generation, high speed, high rigidity, low noise, high wear resistance, etc., it is required that the bearing steel should have the characteristics of high hardness, uniform hardness, high elasticity, and high limit. .
Under normal circumstances, the slewing bearing rolling element adopts integrally hardened carbon chromium bearing steel. The grade is made of GCr15 or GCr15SiMn steel; the slewing bearing ring is made of surface hardened steel. When the user has no special requirements, it is generally made of 50Mn steel, but sometimes in order to meet the needs of the host in some special applications, it can also be provided by the user. For specific use conditions, select other grades of surface hardened steel, such as 42CrMo, 5CrMnMo, etc.
(1) 42CrMo is a high-carbon steel with good quenching and tempering performance and quenching performance. It is an ideal material for slewing bearings.
(2) 50Mn has good hardenability and is also a high-quality choice for slewing bearings.
(3) 40Cr is also good in terms of mechanical properties, and it is still in the stage of exploration and practice.
(4) GCr15 small slewing bearing can be selected, but it is generally not recommended to use it because of the trouble of milling and drilling in the process due to the full quenching.
2. Material for cage
The cage for slewing bearings has a structure such as an integral type, a segmented type, and a spacer type. Among them, the integral and segmented cages are made of No. 20 steel or ZL102 cast aluminum alloy. The isolation block is made of polyamide 1010 resin, ZL102 cast aluminum alloy, etc.
3. Sealing ring materials
The slewing bearing seal ring is made of oil-resistant rubber or nitrile rubber.
The code of the ferrule material and the supply status of the blank is in accordance with the regulations in the table. In the table, “T” indicates that the ferrule blank is supplied in the quenched and tempered state, and “Z” indicates that the ferrule blank is supplied in the normalized state.
The slewing bearing seal ring is made of oil-resistant rubber or NBR nitrile rubber. Compared with nitrile rubber, hydrogenated nitrile rubber has better oil resistance, but if you are not too demanding on oil resistance, use nitrile rubber, because hydrogenated nitrile rubber is relatively expensive. Nitrile rubber also has a certain degree of acid and alkali resistance. However, silica gel should be selected if the requirements for oil resistance and acid and alkali are higher, but its price is higher.
In summary, we know that the materials used in slewing bearings are related to their main body and parts. The main body is made of metal, while other parts, such as seals, are made of rubber. If you need this kind of bearing, you must pay attention to the integrity of these materials and high-quality effects when purchasing to ensure the function of the operation. Luoyang Hengguan Bearing provides high-quality, high-performance slewing bearing products for market customers. Everyone is welcome to call for detailed consultation.