Yaw system of wind turbine generator and method for controlling torque transmission of yaw system

Abstract

The invention discloses a yaw system of a wind turbine generator and a method for controlling torque transmission of the yaw system. The yaw system comprises a yaw motor, a gearbox and a fixed torque structure, the fixed torque structure comprises an input shaft connected with the output end of the yaw motor, an output shaft connected with the input end of the gearbox and a torque adjusting assembly, the input shaft is provided with a containing cavity, and the output shaft comprises a torque adjusting part section located in the containing cavity. The input shaft is provided with threaded holes and mounting holes which are evenly distributed in the circumferential direction and extend in the radial direction, the torque adjusting assembly comprises screws matched with the threaded holes, friction pieces abutting against the torque adjusting section and transmission parts arranged in the mounting holes, and the screws abut against the transmission parts through the threaded holes. And the friction piece is pressed against the outer peripheral surface of the torque adjusting section. According to the scheme, the output end of the yaw motor and the input end of the gearbox can rotate relatively by arranging and adjusting the fixed torque structure, so that overlarge reverse torque is effectively released, and the running safety and reliability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a yaw system of a wind turbine set and a method for controlling torque transmission of the yaw system. Background Art

[0002] As the core component of a wind turbine, the yaw drive system has the main function of accurately adjusting the wind angle of the wind turbine blades, aiming to optimize the wind energy capture efficiency and effectively manage the load caused by the change in yaw angle. The yaw drive system generally consists of the following parts: electromagnetic brake, yaw motor, gearbox group, and yaw bearing. Its working principle is: when the wind angle of the wind turbine meets the power generation requirements, the electromagnetic brake is in the engaged state, and works with the hydraulic brake installed at the bottom of the main frame of the unit to provide a stable braking torque to ensure that the wind turbine can accurately maintain the optimal wind angle. However, when the wind turbine's wind angle deviates from the power generation requirements, the system will first reduce the braking torque by adjusting the hydraulic brake, and then the electromagnetic brake will quickly repel, so that the yaw system is in a low torsional damping state. At this time, the yaw motor transmits the torque to the yaw bearing ring gear through the gearbox, overcomes the damping to complete the yaw action, and adjusts the wind angle. After the yaw action is completed, the electromagnetic brake is engaged again and the hydraulic brake is fully tightened to ensure that the wind turbine is stable at the new wind angle.

[0003] At the beginning and end of the continuous yaw action, the hydraulic brake torque will be temporarily reduced, and only the electromagnetic brake will bear the main braking torque. If there is a sudden change in wind direction during this period, the rotation direction of the yaw motor may be opposite to the direction of the wind load, which may cause the yaw bearing to drag in the opposite direction. Once reverse drag occurs, the gearbox group will rotate in the opposite direction. Since the total backlash values ​​of each gearbox in the gearbox group are different, the reverse impact will occur at the gearbox and bearing with the smallest total backlash value. In the design of the yaw system, the load is shared by multiple gearboxes in the gearbox group. The wind load exceeds the designed safety margin. This reverse force is very likely to overcome the damping of the hydraulic brake, causing serious faults such as gear breakage in the yaw gearbox or yaw bearing ring gear. Gear breakage may cause the yaw action to fail to complete, and under extreme conditions, major accidents such as blade breakage and unit collapse may occur.

[0004] In view of this, designing a new yaw transmission system to cope with the impact of reverse dragging of the yaw bearing and reduce the risk of tooth breakage in the yaw system has become an urgent problem to be solved in the current wind power industry. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the prior art and to provide an impeller device for a wind turbine.

[0006] In order to achieve the above object, the present invention proposes a yaw system of a wind turbine generator set, comprising:

[0007] Yaw motor, equipped with electromagnetic brake;

[0008] A gear box, an output end of which is connected to a yaw gear for driving an outer gear ring of a yaw bearing;

[0009] A constant torque structure comprises an input shaft connected to the output end of the yaw motor, an output shaft connected to the input end of the gear box and a torque adjustment component, wherein the input shaft is provided with a receiving cavity coaxial with the input shaft, the output shaft comprises a torque adjustment section located in the receiving cavity, the input shaft is provided with threaded holes uniformly distributed in the circumferential direction and extending in the radial direction, and a mounting hole coaxial with and connected to the threaded holes, the torque adjustment component comprises a screw matching the threaded hole, a friction member abutting against the outer peripheral surface of the torque adjustment section, and a transmission member arranged in the mounting hole and located between the screw and the friction member, the screw presses the transmission member via the threaded hole so that the friction member presses the outer peripheral surface of the torque adjustment section.

[0010] Furthermore, the transmission component includes a disc spring group and a gasket, and the gasket is arranged between the disc spring group and the threaded end of the screw, so that the disc spring group is elastically compressed under the tightening action of the screw.

[0011] Furthermore, the disc spring assembly includes at least one pair of disc springs whose small diameter ends are butted against each other.

[0012] Furthermore, the friction member includes a pressing block and a friction pad, the inner side surface of the friction pad is configured as an arc surface matching the outer peripheral surface profile of the output shaft, and the outer side surface is attached to the pressing block.

[0013] Furthermore, the pressing block is provided with a protruding column on a side opposite to the friction pad, the protruding column extending into the mounting hole and abutting against the transmission component.

[0014] Furthermore, the pressing block is provided with two protruding columns spaced apart in the height direction.

[0015] Furthermore, the yaw system includes six groups of constant moment structures distributed at equal intervals along the circumferential direction.

[0016] Furthermore, the torque adjustment section of the output shaft is constructed as a flat columnar structure with a cross-sectional radius greater than its height.

[0017] Furthermore, the output shaft of the constant torque structure and the input end of the gear box are integrally formed.

[0018] The present invention also provides a method for controlling the torque transmission of a yaw system. Based on the above yaw system, the method comprises:

[0019] Calculate the range of reverse torque values ​​acting on the input shaft of the gearbox when reverse drag of the yaw bearing occurs at the start and / or end of the yaw operation of the unit, when the output shaft of the yaw motor is directly connected to the input shaft of the gearbox;

[0020] Determine a friction torque threshold between the input shaft and the output shaft of the constant torque structure, so that the friction torque threshold is less than the minimum value of the above reverse torque value range;

[0021] The screw-in depth of the screw is adjusted so that the actual friction torque between the input shaft and the output shaft of the fixed torque structure does not exceed the above-mentioned friction torque threshold.

[0022] The present application scheme can control the friction torque value transmitted to the output shaft by the torque adjustment component by adjusting the screw insertion depth. When the yaw bearing is dragged in the reverse direction and the reverse torque exceeds the preset friction torque threshold, relative sliding can occur between the friction member and the output shaft, so that the input shaft and the output shaft of the constant torque structure rotate relative to each other, and then the output end of the yaw motor and the input end of the gearbox rotate relative to each other, thereby effectively releasing the excessive reverse torque to protect the entire yaw system from damage, ensure the long-term stable operation of the wind turbine, and improve safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following drawings of the present invention are used as part of the present invention for understanding the present invention. The drawings show the embodiments of the present invention and their descriptions, and are used to explain the device and principle of the present invention. In the drawings,

[0024] Figure 1 It is a schematic diagram of the installation layout of the yaw system in the unit according to an embodiment of the present invention;

[0025] Figure 2 It is a front structural schematic diagram of a yaw system according to an embodiment of the present invention;

[0026] Figure 3 The constant moment structure of the yaw system of the embodiment of the present invention ( Figure 2 A cross-sectional view of part B in FIG.

[0027] Figure 4 It is a schematic diagram of the three-dimensional structure of the output shaft and the torque adjustment assembly of the constant torque structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. The described embodiments are only preferred embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be understood that, unless otherwise defined, the technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present invention. Terms such as "parts" and "pieces" that appear in this article can represent both single parts and combinations of multiple parts. The singular forms of "one", "an" and "said / the" are also intended to include plural forms unless the context clearly indicates otherwise. Ordinal numbers such as "first" and "second" are merely identifiers and do not have any other meaning, such as a specific order, etc. Moreover, for example, the term "first component" itself does not imply the existence of a "second component", and the term "second component" itself does not imply the existence of a "first component". When the terms "comprising" and / or "including" are used in this specification, it indicates the presence of the features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof. The terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", "center", "vertical", "horizontal" and similar expressions are for illustrative purposes only and are not limiting. The terms "connect", "install", "connected", and "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The features described in this document in one embodiment may be applied to another embodiment alone or in combination with other features, unless the feature is not applicable in the other embodiment or otherwise specified.

[0030] Hereinafter, specific embodiments of the present invention will be described in more detail with reference to the accompanying drawings. These drawings show representative embodiments of the present invention and do not limit the present invention.

[0031] The present invention provides a yaw system for a wind turbine. Figure 1-4As shown, the yaw system includes a yaw motor 1 provided with an electromagnetic brake, a gearbox 2 and a constant torque structure, wherein the output end of the gearbox 2 is connected to a yaw gear 5 for driving an outer gear ring 4 of a yaw bearing. The constant torque structure includes an input shaft 3 connected to the output end of the yaw motor 1, an output shaft 4 connected to the input end of the gearbox 2 and a torque adjustment assembly, wherein the input shaft 3 is provided with a receiving cavity coaxial with the input shaft 3, the output shaft 4 includes a torque adjustment section 41 located in the receiving cavity, the input shaft 3 is provided with threaded holes uniformly distributed in the circumferential direction and extending in the radial direction and a mounting hole coaxial with and connected to the threaded hole, the torque adjustment assembly includes a screw 5 matched with the threaded hole, a friction member 6 abutting against the outer peripheral surface of the torque adjustment section 41, and a transmission member 7 arranged in the mounting hole and located between the screw 5 and the friction member 6, the screw 5 presses the transmission member 7 via the threaded hole, so that the friction member 6 presses the outer peripheral surface of the torque adjustment section 41. When the unit performs yaw operation, the driving torque output by the yaw motor 1 is introduced into the fixed torque structure by the input shaft 3, and is transmitted to the output shaft 4 via the friction member 6 that rotates with the input shaft 3, so as to realize the smooth conversion of the driving force; by adjusting the screw-in depth, the friction torque value transmitted to the output shaft 4 by the torque adjustment component can be controlled. When the yaw bearing is dragged in the reverse direction and the reverse torque exceeds the preset friction torque threshold, relative sliding can occur between the friction member 6 and the output shaft 4, so that relative rotation occurs between the input shaft 3 and the output shaft 4, that is, relative rotation occurs between the output shaft of the yaw motor 1 and the input shaft of the gearbox 2, thereby effectively releasing the excessive reverse torque to protect the entire yaw system from damage, ensure the long-term stable operation of the wind turbine, and improve safety and reliability.

[0032] According to an embodiment of the present invention, the transmission component 7 may include a disc spring group 71 and a gasket 72. The gasket 72 is arranged between the disc spring group 71 and the threaded end of the screw 5, so that the disc spring group 71 is elastically compressed under the tightening action of the screw 5, thereby transmitting the pressure to the friction member 6, so that the friction member 6 presses the output shaft 4; the disc spring group 71 includes at least one pair of disc springs with small diameter ends butted against each other. The elastic force generated by the compression of the disc spring group is conducive to maintaining the compression state between the friction member 6 and the output shaft 4, so as to provide a stable friction torque. The friction member 6 includes a pressing block 61 and a friction pad 62. The inner side of the friction pad 62 is set to be an arc surface matching the outer peripheral surface profile of the output shaft 4, and the outer side can be attached to the pressing block 61 by bonding. The pressing block 61 is provided with a boss 611 extending into the mounting hole of the input shaft 3 and abutting against the transmission component 7 on the side opposite to the friction pad 62. The boss 611 of the pressing block 61 is embedded in the mounting hole of the input shaft 3, which helps to fix the transmission component 7 in the mounting hole and can avoid relative sliding between the friction member 6 and the transmission component 7. Preferably, each pressing block 61 is provided with two bosses 611 spaced apart in the height direction, and the two bosses 611 are respectively embedded in the two mounting holes of the input shaft 3, and are firmly pressed to the outer peripheral surface of the output shaft 4 under the action of the upper and lower screws 5 and the two groups of transmission components 7. In order to form a stable torque transmission between the friction member 6 and the output shaft 4, the torque adjustment section 41 of the output shaft 4 is constructed as a flat columnar structure with a cross-sectional radius greater than its height, so as to increase the contact area with the friction member 6. Preferably, six groups of constant torque structures distributed at equal intervals along the circumferential direction can be provided to ensure that the transmission of the friction torque is more balanced and reliable. Further preferably, the output shaft 4 of the constant torque structure and the input end of the gear box 2 are constructed as an integrally formed structure.

[0033] The present invention also provides a method for controlling the torque transmission of a yaw system based on the above yaw system, comprising the following steps:

[0034] S1: Calculate the range of reverse torque values ​​acting on the input shaft of gearbox 2 when reverse drag of the yaw bearing occurs at the start and / or end of the unit yaw operation;

[0035] This step assumes that the yaw system does not include a constant torque structure, that is, it is necessary to directly connect the output shaft of the yaw motor 1 with the input shaft of the gearbox 2. The specific calculation can be implemented by wind turbine simulation software.

[0036] S2: Determine a friction torque threshold between the input shaft 3 and the output shaft 4 of the constant torque structure, so that the friction torque threshold is smaller than the minimum value of the above reverse torque value range.

[0037] S3: Adjust the screwing depth of the screw 5 so that the actual friction torque between the input shaft 3 and the output shaft 4 of the constant torque structure does not exceed the above-mentioned friction torque threshold.

[0038] The present invention has been described through the above-mentioned embodiments, but it should be understood that the above-mentioned embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present invention is not limited to the above-mentioned embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention. The protection scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A yaw system for a wind turbine, characterized in that: include: A yaw motor (1) provided with an electromagnetic brake; A gear box (2), the output end of which is connected to a yaw gear (5) for driving an outer gear ring (4) of a yaw bearing; A constant torque structure comprises an input shaft (3) connected to the output end of the yaw motor (1), an output shaft (4) connected to the input end of the gear box (2), and a torque adjustment component, wherein the input shaft (3) is provided with a receiving cavity coaxial with the input shaft, the output shaft (4) comprises a torque adjustment section (41) located in the receiving cavity, the input shaft (3) is provided with threaded holes uniformly distributed in the circumferential direction and extending in the radial direction, and a mounting hole coaxial with and connected to the threaded hole, the torque adjustment component comprises a screw (5) matching the threaded hole, a friction member (6) abutting against the outer peripheral surface of the torque adjustment section (41), and a transmission member (7) arranged in the mounting hole and located between the screw (5) and the friction member (6), the screw (5) presses against the transmission member (7) via the threaded hole so that the friction member (6) presses against the outer peripheral surface of the torque adjustment section (41).

2. The yaw system according to claim 1, characterized in that: The transmission component (7) comprises a disc spring group (71) and a gasket (72), wherein the gasket (72) is arranged between the disc spring group (71) and the threaded end of the screw (5), so that the disc spring group (71) is elastically compressed under the tightening action of the screw (5).

3. The yaw system according to claim 2, characterized in that: The disc spring group (71) comprises at least one pair of disc springs whose small diameter ends are butted against each other.

4. The yaw system according to claim 1, characterized in that: The friction member (6) comprises a pressing block (61) and a friction pad (62); the inner side surface of the friction pad (62) is arranged as an arc surface matching the outer peripheral surface profile of the output shaft (4), and the outer side surface is attached to the pressing block (61).

5. The yaw system according to claim 4, characterized in that: The pressing block (61) is provided with a protruding column (611) on a side opposite to the friction pad (62), the protruding column extending into the mounting hole and abutting against the transmission component (7).

6. The yaw system according to claim 5, characterized in that: The pressing block (61) is provided with two protruding columns (611) spaced apart in the height direction.

7. The yaw system according to claim 1, characterized in that: It includes six groups of constant moment structures which are equally spaced along the circumferential direction.

8. The yaw system according to claim 1, characterized in that: The torque adjustment section (41) of the output shaft (4) is constructed as a flat columnar structure with a cross-sectional radius greater than its height.

9. The yaw system according to any one of claims 1 to 8, characterized in that: The output shaft (4) of the constant torque structure and the input end of the gear box (2) are an integrally formed structure.

10. A method for controlling torque transmission of a yaw system, based on the yaw system according to any one of claims 1 to 9, characterized in that: include: Calculating the range of reverse torque values ​​acting on the input shaft of the gearbox (2) when the yaw bearing reversely drags at the start and / or end of the yaw operation of the unit when the output shaft of the yaw motor (1) is directly connected to the input shaft of the gearbox (2); Determining a friction torque threshold between an input shaft (3) and an output shaft (4) of the constant torque structure, so that the friction torque threshold is less than a minimum value of the above-mentioned reverse torque value range; The screwing depth of the screw (5) is adjusted so that the actual friction torque between the input shaft (3) and the output shaft (4) of the fixed torque structure does not exceed the above-mentioned friction torque threshold value.

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