As the core basic components of the industry, oil film bearings directly determine the production efficiency and safety of equipment, and have strong industrial radiation and influence. Combined with years of research work on oil film bearings, this paper summarizes its structural design, lubrication theory, creep theory, bonding strength theory, bonding process, test and pilot platform construction, and on this basis, puts forward high-quality development of oil film bearings the main direction.
Oil film bearings are radial sliding bearings with lubricating oil as the lubricating medium, also known as liquid friction bearings. They have incomparable advantages over general sliding bearings and rolling bearings, such as small friction factor, large bearing capacity, long service life, and strong impact resistance. . Oil film bearings are widely used in high-precision, high-end key equipment in steel, mining, metallurgy, wind power, ships, aerospace, aviation and other systems. The oil film bearings used in various rolling mills are called rolling oil film bearings, which can be regarded as It is the “heart” of the rolling machine, and its operation performance is directly related to the production efficiency and safety of the equipment. The research of oil film bearing is a systematic engineering technology involving multidisciplinary knowledge such as machinery, materials, mechanics, mathematics, control, computer, physics, chemistry, etc. A review is made on the construction of the pilot test platform.
Structural Design of Oil Film Bearings
Taking the rolling oil film bearing as an example, the bushing and the taper sleeve are the main radial bearing parts. The bushing material is composed of a steel matrix and a babbitt alloy, and the taper bushing is made of high-hardness forged steel. The bushing is fixed to the bearing seat by a fixing pin, and the taper sleeve is connected to the shaft by a key. When the bearing is working, the taper sleeve rotates with the shaft at a certain speed, bringing lubricating oil with a certain viscosity into the oil wedge, forming a complete lubricating oil film in the working area of the taper sleeve and the bushing, and the lubricating oil generates a certain dynamic pressure , Taper Roller Bearing when the resultant force of the dynamic pressure can balance the radial load (including self-weight) borne by the bearing, the tapered sleeve and the surface of the bushing are out of contact due to the presence of the oil film. At this time, the friction between the bearing working surfaces is pure liquid friction.
The evolution of the tapered sleeve structure of oil film bearings has developed from the initial long key bearing to the short key bearing, then to the full keyless bearing, until now the widely used thin-walled keyless bearing. The application of keyless technology improves and eliminates the change of rolling force caused by the keyway and the wear of the adjacent area of the keyway at the connection of the original taper sleeve, reduces the stress concentration and plastic deformation, ensures the neutrality, improves the running accuracy and is easy to use. For disassembly and assembly, it is crucial to enhance the rigidity of the taper sleeve and improve the uniformity of product thickness.
A method for predicting the service life of the taper sleeve across the macro and micro scales is proposed, and the optimization calculation of the taper sleeve with different wall thicknesses is carried out to determine the optimal range of the taper sleeve wall thickness, and obtain the recommended size range for the taper sleeve thinning. The structural innovation of the wall taper sleeve increases the bearing capacity by nearly 30%, expands the product series of thin-walled oil film bearings, and promotes the standardization and serialization of products.
The evolution of the bushing structure of the oil film bearing has undergone the optimization of the size, number and distribution pattern of the oil cavity, and its bonding process has experienced the application of expanding from centrifugal casting to welding process, in order to achieve thinner processing thickness, higher compressive strength and better bonding performance. Excellent babbitt layer, which can withstand greater loads.