Due to the particularity of the wind power industry, domestic wind power main shaft bearings currently mainly use foreign imported brands, such as FAG, SKF, TIMKEN, NSK and other brands, but the delivery times are not very good. It is currently understood that domestic main shaft bearings can be produced. The highest-level manufacturers are mainly tile bearings. Compared with imported bearings, the delivery period of tile bearings is better, but the main ones are around 1.5-2 MW. Although 5 MW or more is the development trend of the wind power market, I have not heard of any domestic bearings at present. Able to produce products that have been tested by the market.
What is the configuration of wind power spindle bearings?
Right side.
On the right side of the fan main shaft bearing is the positioning bearing. The standard positioning bearing cage is in the form of an upper centerline, which limits the rollers on the inner ring. Locating bearings, on the other hand, may also use a lower centerline cage that confines the rollers to the outer ring. This configuration can be equipped with two independent retaining rings.
The main features and benefits of wind power positioning bearings are: reduced axial space. The single-row bearing replaces the conventional double-row bearing arrangement, which reduces the design space. Therefore, it also reduces the required length and weight of the heavy-duty gearbox case, matching the current design structure. Positioning bearings operating in a 360° load zone have centering properties that improve gear contact positioning. Reduce system costs. Reduces stress and increases bearing life.
The transmission chain of a traditional wind turbine usually consists of a main shaft, a gearbox and a generator. According to the structure and use requirements of different types of wind turbines, the structural shapes of the large main shaft bearings will also be different. . Among all installed wind turbines, 75% to 80% adopt the main shaft bearing support principle, that is, the inner ring of the main bearing is installed on the rotating main shaft.
The main shaft supports the hub and blades and transmits torque to the speed increaser. The main shaft bearing mainly bears radial force. Its performance not only affects the transmission efficiency, but also determines the main transmission chain. The maintenance cost is high, so it is required to have good alignment performance, vibration resistance and smooth operation.
On the spindle, the dual-bearing configuration is a relatively common bearing configuration. The bearing types used vary according to different design requirements, but the more common bearing configuration is spherical rollers. Sub-bearings or tapered rollers are configured with cylindrical roller bearings. High-power wind turbines use large cone angle double-row tapered roller bearings or three-row cylindrical roller bearings.
Among them, the two-point support form is the most typical. The bearing is installed in two independent or a common bearing seat. The rotor end or gearbox end bearing can be designed as a fixed end. bearings. The first form provides a more suitable ratio between radial and axial forces, and the structure of the spindle results in a larger diameter fixed-end bearing solution. In the second form, the position of the shoulder that transmits axial loads behaves more favorably in terms of spindle stress, since it avoids a step in the front bearing position.
Adopt threeIn the case of point support, one point is the fixed end bearing and the other two points are the torque support bearings in the gear box. It is also important to ensure the correct distance between the fixed and floating bearing locations during installation. The axial force must act on the fixed end bearing.
With three-point support, the force acting on the floating end bearing shows the effect of load on the inside of the gearbox. In a two-point supported main bearing arrangement, it is the true floating end bearing that bears this load. Therefore, two-point support shows its advantages over the influence of other factors such as vibration.