A coupling for a wind turbine generator set

Abstract

The present invention discloses a coupling for a wind turbine generator, which includes an input end half coupling (connected to the input shaft by splines), an output end half coupling (formed by the middle part of the brake disc and bolted to the output shaft), and a number of nylon pins and ordinary bolts for connecting the two half couplings. The spline connection can provide dynamic compensation for the axial, radial and angular displacements of the input shaft during operation; the outer extension structure of the output end half coupling can be used as a brake disc; the nylon pins and connecting bolts are designed and selected based on the transmission torque threshold. After the load torque of the output shaft exceeds the threshold, the nylon pins and bolt connections break and fail, disconnecting the connection of the coupling, playing a role in safety protection. The coupling has a simple structure, composite functions and low cost, realizing four functions of normal torque transmission, comprehensive displacement compensation of the input shaft, maintenance braking and safety protection, and is convenient for installation and maintenance at the same time.

Description

Technical Field

[0001] This invention patent relates to a coupling for a wind turbine generator, belonging to the technical field of wind power generation. Background Art

[0002] Wind power is the most valuable power generation method for large-scale development and commercial development prospects in the field of renewable energy. The available wind energy is widely distributed and has huge reserves globally.

[0003] The drive train of a wind turbine is the core component of the wind turbine unit. The commonly adopted solution by the whole machine manufacturers during system integration is that the main shaft, gearbox, and generator are independently designed and provided by different component suppliers. A coupling is set on the high-speed shaft of the drive train to connect the output shaft of the gearbox with the rotating shaft of the medium-high-speed generator.

[0004] The main functions of the coupling are: 1) to effectively transmit the torque of the high-speed shaft or low-speed shaft of the drive train; 2) to dynamically compensate for the displacements in the axial, radial, and angular directions between the output shaft of the gearbox and the rotating shaft of the generator; 3) when a fault occurs at the load end of the wind turbine unit (i.e., the generator output end, usually directly or through an inverter connected to the power grid), ensure that the torque borne by the mechanical components of the drive train is within the designed range, avoid damage to key components such as the gearbox, and at the same time delay the time when the wind turbine stops and disconnects from the grid due to a fault.

[0005] Currently, the commonly used coupling adopts a solution of two half-couplings. Each half-coupling is connected to the output end or input end of the components in the drive train by using a shrink disc or spline connection. After adding a friction plate type torque limiting device between the two half-couplings, they are connected by bolts, and the effect of transmitting torque and limiting torque is achieved by adjusting the pre-tightening of the bolts. Patents such as CN205036515 U, CN 103375498 B, CN 208380755 U, and CN 201284799 Y are all applied based on the above solution. This solution has three disadvantages: 1) Each output end or input end of the components has to use a half-coupling, increasing the cost of the drive train; 2) The torque limiting threshold cannot be accurately set, there is a certain error, and when there are large fluctuations in the input load of the impeller, too conservative settings may affect the torque transmission during normal power generation; 3) The effect of the friction type torque limiting will be discounted after the slipping phenomenon occurs, increasing the risk. Summary of the Invention

[0006] A coupling for a wind turbine generator includes an input end half-coupling, which is connected to the input shaft by a spline connection; an output end half-coupling, which is composed of the middle part of a brake disc and is connected to the output shaft by bolts; nylon pins and bolts, which connect the input end half-coupling and the output end half-coupling.

[0007] The output shaft is the rotating shaft of the generator, with an inner diameter larger than the outer diameter of the input shaft, enclosing the input shaft inside. At least one set of bearings and bearing seats are provided inside the generator or on the end cover to support the rotation of the input shaft inside the output shaft. The connections between the input shaft and the half coupling, between the output shaft and the middle part of the brake disc, and between the input-end half coupling and the output-end half coupling are all located at the tail of the generator. After the rear end cover of the generator is removed, installation and maintenance work can be directly carried out. The connection between the input-end half coupling and the output-end half coupling is a rigid connection, and the connection between the input shaft and the half coupling provides dynamic compensation for the axial, radial, and angular displacements that occur during the operation of the input shaft.

[0008] An insulating material is added to the bolt connection between the input-end half coupling and the output-end half coupling, or between the output-end half coupling and the output shaft, or to the middle part of the brake disc to form electrical insulation between the input shaft and the output shaft.

[0009] The nylon pins and bolts are designed and selected according to the transmission torque threshold. After the load torque of the output shaft exceeds the threshold, the nylon pins and bolts break and fail, disconnecting the connection between the input-end half coupling and the output-end half coupling.

[0010] The beneficial effects of the present invention are as follows: The present invention provides a composite coupling for the drive train of a wind turbine. This structure utilizes the connection between the brake disc of the generator and the spline coupling to achieve four functions: normal torque transmission, comprehensive displacement compensation of the output shaft, maintenance braking, and safety protection. At the same time, the traditional friction-type torque limiting device is abandoned, and the safety protection effect is achieved through the bearing capacity of the nylon pins and bolts themselves. The overall structure is simple, the functions are composite, the cost is low, and it is convenient for installation and maintenance. Description of the Drawings

[0011] Figure 1 It is a schematic diagram of a coupling for a wind power generation unit

[0012] Description of the Drawings: 1 - Input shaft half coupling, 2 - Output shaft half coupling, 3 - Nylon pin, 4 - Bolt, 5 - Input shaft, 6 - Flange surface, 7 - Brake disc, 8 - Output shaft, 9 - Front end cover of the generator, 10 - Bearing, 11 - Bearing seat, 12 - Rear end cover of the generator.

[0013] It should be noted that the above drawings are used to illustrate the features of the present invention and are not intended to show any actual structure or reflect details such as the dimensions and relative proportions of various components. In order to more clearly show the principle of the present invention and to avoid unnecessary details from obscuring the principle of the present invention, the examples in each figure have been simplified. These drawings will not cause inconvenience to those skilled in the relevant field in understanding the present invention, and the actual coupling may include more components. Detailed Embodiments

[0014] For the purpose of making the objectives and technical solutions of the embodiments of the present invention clearer, the following will provide a complete description of the embodiments of the present invention in combination with the relevant drawings of the embodiments of the present invention. This patent describes a part of the embodiments, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0015] As Figure 1 shown, the coupling for a wind turbine generator set includes an input shaft half coupling 1, an output shaft half coupling 2, nylon pins 3 and bolts 4. The input shaft 5 can be the high-speed shaft of a gearbox, and after being connected to the input shaft half coupling 1 through a spline, a flange surface 6 of the input shaft 5 is formed. The middle part of the brake disc 7 is connected to the output shaft 8, and the connection method can be bolt connection. Multiple bolt holes are reserved in the middle part of the brake disc 7, and these bolt holes need to cooperate with the input end half coupling 1. The nylon pins 3 play the role of connecting the two half couplings and transmitting torque, and the bolts 4 achieve the axial fixation of the two half couplings.

[0016] The output shaft 8 is the rotating shaft of the generator, and its inner diameter is larger than the outer diameter of the input shaft 5, surrounding the input shaft 5 inside. At least one set of bearings 10 and bearing seats 11 are provided on the front end cover 9 of the generator to support the rotation of the input shaft 5 inside the output shaft 8.

[0017] The input shaft 5, as the high-speed shaft of the gearbox, extends all the way to the tail of the generator. Therefore, the connections between the input shaft 5 and the input shaft half coupling 1, between the output shaft 8 and the middle part of the brake disc 7, and between the input end half coupling 1 and the output end half coupling 2 are all located at the tail of the generator. After the rear end cover 12 of the generator is disassembled, installation and maintenance work can be directly carried out. The connection between the two half couplings is a rigid connection, while the connection between the input shaft 5 and the input half coupling 1 is a rigid movable connection, which provides dynamic compensation for the axial, radial and angular displacements that occur in the input shaft 5 during operation.

[0018] The bolt connection between the input end half coupling 1 and the output end half coupling 2, or the bolt connection between the output end half coupling 2 and the output shaft 8, or an insulating material is added to the middle part of the brake disc 7 to form electrical insulation between the input shaft 5 and the output shaft 8.

[0019] The nylon pins 3 and bolts 4 are designed and selected according to the transmission torque threshold. After the load torque of the output shaft 8 exceeds the threshold, the nylon pins 3 and bolts 4 break and fail, and the connection between the input end half coupling 1 and the output end half coupling 2 is disconnected.

Claims

1. A coupling for a wind turbine generator set, characterized by: The coupling includes an input half coupling, which is connected to the input shaft through a spline; an output half coupling, which is composed of the middle part of the brake disc and is connected to the output shaft through bolts; nylon pins and bolts are used to connect the input half coupling and the output half coupling; The input shaft and input half coupling, the middle part of the output shaft and the brake disc, and the connection between the input half coupling and the output half coupling are all located at the tail of the generator. After the rear end cover of the generator is removed, installation and maintenance work can be carried out directly. The nylon pins and bolts are designed and selected according to the transmission torque threshold. When the output shaft load torque exceeds the threshold, the nylon pins and bolts break and fail, and the connection between the input half coupling and the output half coupling is disconnected.

2. A coupling for a wind turbine generator set according to claim 1, characterized in that: The inner diameter of the output shaft is larger than the outer diameter of the input shaft, and surrounds the input shaft inside.

3. The coupling for a wind turbine generator set according to claim 1, wherein: The output shaft is the generator shaft. At least one set of bearings and bearing seats are provided inside the generator or on the end cover to support the input shaft to rotate inside the generator shaft.

4. A coupling for a wind turbine generator set according to claim 1, characterized in that: The connection between the input half coupling and the output half coupling is a rigid connection, and the connection between the input shaft and the input half coupling provides dynamic compensation for axial, radial and angular displacements of the input shaft during operation.

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