Bulk Truck Crane Slewing Bearing
Table of Contents
1.Causes and anti-rust methods of slewing bearing rust
Slewing bearing is a kind of large bearing with special structure. It is widely used in many construction machinery or equipment platforms. If the bearing is stored or used improperly, it may cause rust, which will affect the use effect.
The cause of corrosion
1. The relative humidity is too high
The relative humidity we often say refers to the ratio of the water vapor content in the air to the saturated water vapor content of the air at the same temperature, usually expressed as a percentage. The relative humidity is proportional to the humidity in the air. The higher the relative humidity, the faster the metal corrosion. In general, the critical relative humidity of steel is 70%.
2. The temperature increases to speed up the chemical reaction
When the air is humid, the metal will interact with the oxygen and water in it. Above the critical temperature, condensation will form on the metal surface, resulting in corrosion. If the relative humidity reaches the critical humidity of the metal, the effect of temperature will change.
Obviously, as the temperature increases, the reaction speed continues to accelerate, resulting in corrosion of the bearing.
3. The effect of oxygen
Oxygen can be dissolved in water during the storage process of the slewing bearing. The corrosion phenomenon of oxygen concentration difference is relatively common, and the solubility of different parts will change.
When the bearings are stacked, the oxygen is insufficiently inflated in the middle of the overlapping surface, the concentration in the water is low, the oxygen at the edge is sufficient, and the concentration in the water is high, which will cause rust around the edge of the overlapping surface.
4. Effects of pollutants in the atmosphere
The atmosphere contains a variety of pollutants, such as carbon dioxide, nitrogen oxides, carbon dioxide and other gases and solid dust. These pollutants will condense on the metal surface together with the water mist in the air, and dissolve in water to produce the following results: various non-metallic oxides dissolve in water to become acids, which will destroy the passive film on the metal surface and cause
rust.
2. Anti-rust method
1. Immersion method
After cleaning the slewing bearing, it is immersed in a solution of 5% sodium nitrite and 0.6% sodium carbonate. The anti-rust effect is good, but many anti-rust tanks and other equipment are required, which take up a lot of space and are inconvenient to manage.
2. Spray method
Use filtered compressed air with a pressure of about 0.7Mpa to spray in a clean air place. The spray method is suitable for solvent-diluted anti-rust oil or thin-layer anti-rust oil, and fire protection and labor protection measures are required.
3. Use special rust remover for bearings
The special rust remover for bearings is a rust removal product that can remove rust but does not damage the material of parts. After rust removal, it can maintain the original color of the product metal.
2.Crane Slewing Bearing
Cranes are robust machines with a wide range of motion and high load capabilities. Slew rings play a valuable role in crane operation, which is why durable designs and regular maintenance are vital to a ring’s overall function.
At LYMC, our slew rings for cranes, and various other applications, offer durability from beginning to end. With regular maintenance, our components are a cost-effective solution for any design.
The Function of a Crane Slew Bearing
In lifting equipment like cranes, slew rings create a joint between the undercarriage and the upper structure of the machine. These slewing bearings allow cranes to turn 360 degrees while supporting other diverse movement requirements, from thrust and radial motion to tilting.
The slewing ring’s open design allows hydraulic systems and other control components to pass through the ring for more efficient use of space.
Slew rings play a critical role in crane operation due to their many responsibilities. While crane slewing bearings regulate many movement types, they also withstand the weight of the equipment and its various loads, including payload and counterbalance.
Since cranes are rated at their maximum capable lifting load, it is important to review how far away from the center of the crane this load can be lifted. This is directly related to the crane slew bearing and is referred to as “Tiling Moment Capacity.”
A crane may have multiple vital components for its operation, but a slew ring is the most critical component in designing a crane load chart. Overall, the slew ring will reflect how much load a crane can lift, and the allowed distance where this load can be lifted at safe operating conditions.
