Turntable bearing is a kind of large bearing with special structure, which can bear the comprehensive load such as large axial load, radial load and overturning moment at the same time, and integrates the functions of supporting, rotating, driving and fixing in one.
An overview of the
Turntable bearing is a kind of large bearing with special structure, which can bear the comprehensive load such as large axial load, radial load and overturning moment at the same time, and integrates the functions of supporting, rotating, driving and fixing in one.
Basic structure
Turntable bearings are usually composed of four major components, such as inner ring, outer ring, rolling body and isolation block. Because the core component adopts slewing bearing, it can bear both axial and radial forces. Its form is many, but the structure composition is basically the same little difference.
From left and right are respectively (upper part) : 1. Outer ring (with or without teeth) 2. Sealing belt 3. Roller (ball or roller) 4. Refueling nozzle
From left and right are respectively (lower part) : 1. Stopper 2. Taper pin 3. Inner ring (tooth or no tooth) 4. Isolation block or cage 5. Mounting holes (wire or light holes)
Series turntable bearings
Single-row four-point contact ball turntable bearing is composed of inner ring, outer ring, steel ball and isolation block. It has compact structure and light weight. The steel ball and circular raceway contact at four points and can bear axial and radial forces at the same time. Rotary conveyors, welding operators, small and medium-sized cranes and excavators and other construction machinery can be selected.
Series turntable bearings
The double volleyball turntable bearing has three seat rings, and the steel ball and the isolation block can be directly discharged into the upper and lower raceway. According to the stress condition, the upper and lower rows of steel balls with different diameters are arranged. This kind of open assembly is very convenient. The bearing Angle of the upper and lower arc raceway is 90°, which can withstand great axial force and tipping moment. When the radial force is greater than 0.1 times the axial force, raceway must be specially designed. The axial and radial dimensions of the double diameter ball slewing bearing are large and the structure is tight. Especially suitable for the requirements of medium diameter tower crane, truck crane and other loading and unloading machinery.
In general, turntable bearing rings are 50Mn, but sometimes 42CrMo is selected to meet the needs of the main engine in special applications. The following article will introduce the use of bearings. What are the specific methods? Want to understand the small partner can be with this small make up a look!
Lubrication of bearings
Most turntable bearings work under the condition of heavy load and low speed. In general, very satisfactory results can be achieved by using the lubrication type filled with grease to lubrify the bearings. Commonly used greases include calcium grease, lithium grease, aluminum grease, and high temperature grease, etc. Users can choose the most suitable grease according to the specific situation.
Seal of bearing
On the one hand, the seal of the turntable bearing is to prevent the filled grease from leaking outwards, on the other hand, to prevent the outside dust, impurities and water from invading the inside of the bearing and affecting its normal work. Because most turntable bearings work under heavy load and low speed, the sealing type of bearings adopts rubber sealing ring and labyrinth sealing structure. The rubber sealing structure itself has the advantages of simple structure, small space occupation, reliable sealing performance and so on, and has been widely used, but its disadvantage is that the rubber sealing lip is easy to early aging and lose the sealing property at high temperature, so the turntable bearing working under high temperature conditions should use labyrinth seal.
Three-row combination roller turntable bearing (slewing support)
The three-row roller slewing bearing has three seat rings and radial raceway separately, so that the load of each row of rollers can be exactly determined, and can bear various loads at the same time. It is the largest bearing capacity of the four kinds of products. The shaft and radial size are large and the structure is firm, especially suitable for heavy machinery requiring large diameter. Such as bucket excavator, wheeled crane, Marine crane, ladle slewing and large tonnage truck crane and other machinery.
Double row angular contact ball turntable bearing (slewing bearing)
Double volleyball slewing bearing has three seat rings, raceway must be specially designed. The axial and radial dimensions of the double volleyball slewing support are relatively large, and the structure is firm. It is especially suitable for the loading and unloading machinery of the tower crane and the truck crane with the diameter above the medium.
Single row cross roller turntable bearing (slewing support)
Single row cross roller slewing bearing, composed of two seat rings, compact structure, light weight, high manufacturing accuracy, small assembly clearance, high requirements for installation accuracy, roller is 1:1 cross arrangement, can bear axial force, large radial force and tipping moment at the same time. It is widely used for lifting, construction machinery and military products.
Single row four point contact ball turntable bearing (slewing bearing)
Single-row four-point contact ball bearing slewing bearing is composed of two seat rings, compact structure, light weight, steel ball and arc raceway contact four points, can withstand axial force, radial force and tipping moment at the same time.
Production process flow chart
Raw materials → Forgings → lathe processing → testing → Heat treatment → grinding processing → testing → tempering → fine grinding → fine grinding → Testing → Assembly → loading → Packing → Packing → Transportation → Customer.
Turntable rotary bearing material: 50Mn, 42CRMO, GCR15SIMN, 9CR18MO.
Rotary bearing accuracy: P0, P6, P5, P4, P2 accuracy from low to high, the price will also be from low to high.
