How to choose the right slewing bearing?

Slewing bearing used in crane, railway, port cranes, crane and metallurgical cranes, container cranes, excavators and other equipment plays an important role in facing the market of all kinds of slewing bearing, we should be how to choose the right slewing bearing?This article mainly introduces how to choose the right slewing bearing. 

The following knowledge points are listed below:

• Commonly used material of the slewing bearing

• How to choose the right slewing bearing?

• Factors influencing slewing bearing selection

1. Commonly used material of the slewing bearing

Slewing bearing is generally made of solid hardened carbon and chromium bearing steel. Made of GCr15 or GCr15SiMn steel;slewing bearing ring is made of surface hardened steel.  When the user has no special requirements, 50Mn steel is generally used to manufacture the bearing ring.  However, in order to meet the needs of some hosts in special applications, other brands of surface hardened steel, such as 42CrMo and 5CrMnMo, can also be selected according to the specific conditions of use provided by the user. 

(1) The materials used for slewing bearing are integral, sublevel and isolation block. The integral and segmented cage is made of no.  20 steel or ZL102 cast aluminum alloy. Isolation block type is made of polyamide 1010 resin, ZL102 cast aluminum alloy, etc. In recent years, with the development of material industry, nylon GRPA66. 25 has been widely used in the design of sectional cage. 

(2) Slewing bearing seal ring material :slewing bearing seal ring material is made of oil-resistant butyl rubber. Ring material and blank supply state code according to the provisions of the table, the table "T" means ring blank for conditioning state supply, "Z" means ring blank in normalizing state supply. The central circle diameter of the rolling body is 3150mm, the ball diameter is 75mm, the gear modulus m=20mm, the ring material is 50Mn, and the bearing of the four-point contact ball slewing with internal teeth made of the blank material is 013. 75. 3150. 12. 

2. How to choose the right slewing bearing?

Slewing bearing (also known as slewing support or rotary disc bearing) is divided into a number of different types, such as four-point contact ball slewing bearing, cross roller slewing bearing, double-row ball disc bearing, double-row cylindrical roller slewing bearing, three-row roller slewing bearing, steel wire raceway slewing bearing, and so on. Each type has different characteristics according to its design and structure, making it suitable for specific applications. For example, the bearing structure of the single-row four-point contact ball slewing is simple, but it can bear heavy radial loads, and also can bear certain axial and overturning loads.  Therefore, the bearing of the single-row four-point contact ball slewing has a high cost performance. But when the mechanism has high requirements on the accuracy and rigidity of the bearing, or the bearing needs to meet the conditions of zero clearance or negative clearance operation, the cross cylindrical roller slewing bearing will be the correct choice. 

3. Factors influencing slewing bearing selection:

(1) Precision of slewing bearing: cross slewing bearing is usually used when precise positioning is a key operating parameter. 

(2) Slewing bearing load: the size of the load is one of the factors that determine bearing size. In general, four-point contact ball slewing bearing can bear heavy loads and impact loads. They are suitable for applications where the load size and direction may vary. 

(3) Slewing bearing's allowable operating temperature: in most cases, slewing bearing's allowable operating temperature is determined primarily by the gasket and sealing material used for lubrication. The allowable operating temperature ranges from -25 to + 70°C. If slewing bearing is required to operate outside the reference temperature, please contact the luoyang bailun bearing engineer. 

(4) Vibration of slewing bearing: for applications involving vibration, four-point contact ball slewing bearing and cross-cylindrical roller slewing bearing are suitable for preloading. 

(5) Velocity of slewing bearing: the friction of four-point contact ball slewing bearing is less than that of cross-cylindrical roller slewing bearing. Four-point contact ball slewing bearing also has a higher rotational speed.

(6) Slewing bearing seals: seals are critical to the performance of slewing bearing. Qualified seals used in slewing bearing provide good protection against moisture and contamination and assure the effectiveness of the grease. If the bearing is operating under extreme conditions, such as exposure to water, vacuum, corrosive contaminants, or radiation, be sure to pay attention to the maintenance of slewing bearing. 

I hope the introduction of this article has helped you understand the selection of slewing bearing.  If you need slewing bearing, please contact us.