The advantages and disadvantages of of wind power main bearing structure
The main disadvantages of this bearing structure are:
Because there is no preload, a single roller may not rotate, resulting in sliding, which will produce a very large peak load, affecting the life of the bearing, for the cylindrical roller bearing used in the unit above 3MW, the roller mass and inertia force are large, and the cylindrical roller bearing may cause the roller to slip and be damaged due to the lack of preload, and the possibility of micropitting corrosion is greater;
2) The size of the main frame is large, the machining accuracy of the bearing chamber is relatively high or composed of more components, and the cost of the main frame is high;
3) The assembly is more complicated;
4) The geometric tolerance requirements such as concentricity of the bearing seat are relatively high.
single row tapered roller bearings with small diameters
The main advantages of this bearing structure are:
1) There is no axial clearance, and the axial positioning is better;
2) The bearing capacity can be increased by increasing the distance between the bearings, and the applicable range of the bearings is larger;
3) The diameter of the bearing is smaller than that of a single bearing, which is easy to manufacture and has a low cost;
4) Due to the long length of the main shaft system, it is easy to obtain a large safety distance from the blade tip (the distance between the blade tip and the tower wall);
5) Because the two bearings are generally in the preload state, the overall stiffness of the shaft system is relatively large, and the structural deformation of the shaft system is relatively small under the action of large dynamic load, and it can bear large dynamic load.
The main disadvantages of this bearing structure are:
1) The size of the main frame is large or composed of more parts, and the cost of the main frame is high;
2) When assembling, it is necessary to adjust the two bearings to a certain amount of preload, so the assembly is more complicated;
3) The concentricity of the two bearing seats is relatively high, and the processing cost is high;
4) The overall length of the transmission chain is long, and the size of the cabin is not compact.
large-diameter single row tapered roller bearings
The main advantages of this bearing structure are:
1) The bearing is generally in a preloaded state, there is no axial clearance, the axial positioning is better, and the preload force is relatively easy to apply;
2) The bearing capacity can be increased by increasing the distance between the bearings, and the applicable range of the bearings is larger;
3) The diameter of the bearing is smaller than that of a single bearing, which is easy to manufacture and the cost is lower than that of a single bearing;
4) Large safety margin, convenient for the development of large blades;
5) Because this kind of configuration generally chooses a smaller roller contact angle, the temperature difference between the moving shaft and the fixed shaft, the temperature change and the assembly error have relatively little impact on the preload of the shaft system, and the bearing life is less affected by the environment and assembly error;
6) The diameter of the shaft is relatively large, and the spacing between the two bearings is relatively small, so the overall stiffness of the shafting system is relatively large, and the structural deformation is small.
The main disadvantages of this bearing structure are:
1) The size of the main frame is large or composed of more components, the machining accuracy of the bearing chamber is high, and the cost of the main frame is high;
2) The bearing is more sensitive to the change of temperature, but for the spindle bearing, due to the low speed and small temperature change, the impact is also relatively small;
3) The shafting assembly is more complex, and the assembly time is longer.
Single bearing
The main advantages of this bearing structure are:
1) There is no axial clearance, and the axial positioning is better;
2) The length of the spindle is short, the transmission chain is compact, and the length of the nacelle can be designed to be relatively short;
3) The diameter of the bearing roller and raceway is large, and the shaft length is short, so the overall stiffness of the shaft system is large, and the structural deformation caused by the load is small;
4) The bearing can be lubricated on both sides, so it is easy to lubricate.
The main disadvantages of this bearing structure are:
1) With the increase of power level, the diameter of the bearing will become larger and larger, for example, the outer diameter of the single bearing of the unit with 6 MW capacity level reaches 3.6 m, and few bearing manufacturers can process and manufacture, so the price is relatively high;
2) Due to the large diameter of the bearing, the bearing seal design is more difficult, the conventional design can not achieve a better sealing effect, and the bearing seal cost is higher;
3) The rollers of the bearing are relatively large, and there is the possibility of sliding, and the sliding of the rollers will affect the life of the bearing;
4) The rollers are similar to cylinders, and when the preload is small, there will be torsion, resulting in all the loads acting on one rotor
unit, which leads to its damage.
Integrated design
The main advantages of this bearing structure are:
1) The shafting is generally in a preloaded state, so there is no axial clearance, and the axial positioning is better;
2) The spindle system is integrated with the gearbox in one. , compact structure, short cabin length;
3) The spindle and gearbox are matched and positioned, and the overall alignment of the transmission chain is good;
4) The force other than torque is directly transmitted to the main frame through the bearing chamber and does not pass through the gearbox, so the gearbox only bears the action of pure torque;
5) Because the gearbox and the spindle system are integrated, the main bearing can be lubricated with oil, which reduces the pollution of the spindle lubrication, improves the lubrication of the bearing, and is beneficial to the life of the bearing.
The main disadvantages of this bearing structure are:
1) In addition to considering the load transmission, the connection mode between the main frame and the gearbox needs to reduce the impact of the vibration of the gearbox;
2) Due to the integration of the main bearing and the gearbox, the maintainability of the main bearing is poor;
3) The bearing is more sensitive to the change of temperature, but for the spindle bearing, because the speed is relatively low, the temperature change is relatively small, so the impact is also relatively small.
Post time: Feb-10-2025
