In recent years, the wind power industry has shown a clear trend of increasing the capacity of individual units. The large-scale capacity of a single unit is an important means to reduce the cost of wind power in the future. The single unit capacity of offshore units has further increased compared to onshore units.

The increase in the proportion of large capacity units will further increase the market space for wind power bearings. Wind turbine bearings are generally composed of a main bearing, three pitch bearings, one yaw bearing, and a combination of gearbox and motor bearings.

Wind turbine spindle sliding bearing

With the rapid development of the world economy, energy shortages and environmental issues have become prominent. Many countries have increased their efforts to develop and utilize environmentally friendly new energy sources. Wind energy, as a green new energy source with abundant energy reserves and broad market prospects, is receiving increasing attention from the world.

Under the pressure of cost reduction in wind power, domestic host companies have paid special attention to the application of sliding bearings in the field of wind power transmission since 2019. Sliding bearings have the advantages of small radial size, strong load-bearing capacity, and low cost. They can be applied to wind power main bearings, gearbox bearings, and other parts, significantly improving bearing torque density and reducing unit torque cost.

Sliding bearings, due to their large contact area, have significantly higher load-bearing capacity, impact resistance, and smooth operation than rolling bearings. Additionally, by eliminating rolling elements, sliding bearings have smaller radial dimensions and are suitable for applications that require compact structures. Therefore, the excellent load-bearing performance and environmental adaptability of sliding bearings are highly compatible with large-scale equipment such as wind power and nuclear power.

Sliding bearings are bearings that operate under sliding friction. It has the characteristics of stable, reliable, and noise free operation. Under liquid lubrication conditions, the sliding surface is separated by lubricating oil without direct contact, which can greatly reduce friction loss and surface wear. The oil film also has a certain ability to absorb vibrations. The part of the shaft supported by bearings is called the journal, and the parts that match the journal are called the bearing shells. The anti friction material layer cast on the inner surface of the bearing shell to improve its friction properties is called a bearing liner. The materials of bearing shells and bearing liners are collectively referred to as sliding bearing materials. The application of sliding bearings is generally under high-speed and light load conditions.

The wind turbine gearbox is one of the key components of wind turbines. It is arranged between the wind turbine and the generator, transmitting the power of the wind turbine to the generator for power generation, and converting the low input speed of the wind turbine into the required speed for the generator. It is installed in a narrow cabin on a tower several tens of meters above the ground, and its volume and mass have a significant impact on the unit. Therefore, the wind turbine gearbox aims to pursue high reliability, minimum volume, and minimum weight. In the wind power gearbox, bearings are important components with a high proportion of failures, and their failure often causes catastrophic damage to the gearbox. At the same time, bearings are valuable components in the gearbox.

Wind power gearboxes require high reliability, long operating time (20-25 years), smooth operation, low noise, small size, and light weight. At the same time, they cannot be replaced during their service life (because the replacement cost is too high, which is even more valuable than one gearbox). Sliding friction occurs during the operation of sliding bearings; The magnitude of sliding friction force mainly depends on manufacturing accuracy; The magnitude of frictional force in sliding bearings mainly depends on the material of the sliding surface of the bearing.

Replacing rolling bearings with sliding bearings for wind turbine spindles and gearboxes is one of the development trends in the wind power industry. With the gradual increase in the use of sliding bearings in wind power bearings, the corresponding market size will also grow rapidly.