What Are the Applicable Temperatures and Common Faults for the Slewing Bearing?

Swing bearing is a very important part in machinery, and virtually every machine cannot function without it. However, due to its fragility, it can also be considered as a consumable item, and it needs to be regularly replaced to ensure the normal operation of the machine.

The applicable temperature of the swing bearing

The standard specifies that the working temperature of rolling bearings for general small and medium-sized motors should not exceed 95℃. What is the actual highest temperature that a bearing can withstand? This is mainly limited by the heat resistance temperature of the bearing steel, cage, sealing material, and thermoplastic material. Ordinary bearing steel has a heat treatment stabilization temperature, below which the bearing maintains stable size and hardness that meets the requirements for use. The heat treatment stabilization temperature for general bearings is 150℃, but it may vary.

Usually, steel or brass cages can withstand a wide range of temperatures. The heat resistance temperature of steel cages can reach 300℃, and that of brass cages can reach 250℃. However, for nylon cages, the temperature range they can withstand is generally -40~+120℃. In order to ensure sufficient depth for transmitting force, one of the rings of the revolving support usually has teeth. Depending on the usage scenario, gear quenching can be divided into full-tooth quenching and single-tooth induction hardening. Single-tooth induction hardening can be further divided into root-face quenching and surface quenching.

With the rapid development of the mechanical industry, swing bearings have been widely used in various industries, such as ship equipment, engineering machinery, light industrial machinery, metallurgical machinery, medical equipment, and industrial machinery. Swing bearings are indispensable components, and once a malfunction happens, it must be dealt with promptly; otherwise, it will affect the normal operation of the machine.

Troubleshooting of common problems in the swing bearing

• If the operation is not flexible and the swing bearing is newly purchased, check the production date of the swing bearing. If the time is long (more than half a year), and the climate is cold, it is likely that the viscosity of the lubricating grease in the raceway is too high, resulting in inflexible operation (especially in cold regions and during winter).

• If the swing bearing often carries heavy loads, it may have difficulty rotating, and even cannot rotate, which is caused by the fact that the larger the tonnage of the crane, the larger the diameter of the swing bearing, and the lower the actual safety factor due to the lower manufacturing accuracy, making it more prone to damage. As much as possible, the safety factor of the swing bearing should be appropriately increased during the design process, and the thickness of the plate connected to the turntable and swing bearing should be increased to improve the structural stiffness of the swing bearing, and thus its load-bearing capacity.
  

• There may be slight noise when the new product runs without load, but it usually disappears after dozens of revolutions. If it does not disappear, it may be due to the slight deformation of the swing bearing during transportation. However, if the operation is flexible and normal, it can be safely installed and used, and it will naturally disappear after a period of use.
  

Swing bearing can work normally from -300℃ to +700℃. If users require swing bearings to adapt to lower or higher temperatures, special sealing rings, protective installations, and suitable oil passages should be used if swing bearings are used in particularly harsh environments, such as marine climate, dust or abrasive particles, sand, cement, coal powder, etc. Therefore, to ensure the normal operation of your bearings, daily maintenance and upkeep are necessary.