Multi-motor confluence driving torque loading system for fan main shaft test

Abstract

The invention discloses a multi-motor confluence driving torque loading system for fan spindle testing, which belongs to the technical field of torque testing of offshore wind turbine spindles and comprises a confluence driving unit, an adjusting unit and a fixing unit. The confluence driving unit comprises a torque transmission assembly and a plurality of groups of low-speed torque loading assemblies; the torque transmission assembly is connected with a tested piece; the plurality of groups of low-speed torque loading assemblies jointly act on the torque transmission assembly to complete large-torque output of the test piece; the confluence driving unit is connected with the fixing unit through the adjusting unit and can adjust the angle of the tested piece. The multi-motor confluence driving torque loading system for the fan main shaft test can effectively solve the problems that in the prior art, when the current mainstream offshore wind turbine generator main shaft torque 100MN. M magnitude test is carried out, the torque of the main shaft is not uniform; the motor is large in size, high in price and difficult to maintain, and the test cannot be continued when the only driving motor breaks down.

Description

Technical Field

[0001] The invention belongs to the technical field of torque testing of the main shaft of an offshore wind turbine. Specifically, it relates to a multi-motor combined flow drive torque loading system for testing the main shaft of a wind turbine. Background Art

[0002] With the rapid development of the global offshore wind power industry, wind turbines are evolving rapidly towards larger sizes and higher capacities. In recent years, the single-unit capacity of mainstream offshore wind turbines has jumped from the early 1.5 MW level to the 16 - 18 MW level, and the world's largest single-unit capacity has even exceeded 26 MW. Along with the capacity increase, the torque parameters of the main shaft of the wind turbine increase exponentially. The main shaft torque of current mainstream models has reached the order of 100 MN·m. This development trend poses unprecedented challenges to the testing technology of the drive train system.

[0003] As the core power transmission system of a wind turbine, the reliability of the drive train is directly related to the overall operation safety and service life of the machine. Before a new type of wind turbine is officially put into operation, it must pass a full-scale drive train bench test, and one of the key items is the torque loading test that simulates the actual working conditions. Traditional testing methods mainly use the direct drive loading method of high-power motors, that is, the drive motor directly applies a set torque value to the drive train under test. However, with the exponential growth of the capacity of the unit under test, the limitations of this technical solution become increasingly prominent: First, to meet the demand for ultra-large torque loading of 100 MN·m level, the volume and weight of the required drive motor increase sharply, resulting in a several-fold increase in the construction cost of the test bench; Second, megawatt-level large-torque direct drive motors need to be developed customized, and their procurement cost is usually as high as tens of millions of yuan, severely restricting the test economy; Third, the installation and commissioning of large-sized motors require the cooperation of special heavy equipment, and professional teams are needed for daily maintenance, significantly increasing the operation and maintenance complexity of the test system; Finally, when a single drive motor fails and needs time for maintenance, the test cannot continue. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-motor combined flow drive torque loading system for testing the main shaft of a wind turbine in view of the above deficiencies, so as to solve the problems of the existing torque loading system, such as large motor size, high price, difficult maintenance, and inability to continue the test when its only drive motor fails, when dealing with the test of the main shaft torque of current mainstream offshore wind turbines at the 100 MN·m level. To achieve the above purpose, the present invention provides the following technical solutions:

[0005] A multi-motor combined flow drive torque loading system for fan main shaft testing, comprising a combined flow drive unit, an adjustment unit and a fixing unit; the combined flow drive unit includes a torque transmission assembly and several groups of low-speed torque loading assemblies; a test piece to be tested is connected to the torque transmission assembly; several groups of the low-speed torque loading assemblies act together on the torque transmission assembly to complete the large torque output of the test piece; the combined flow drive unit is connected to the fixing unit through the adjustment unit, and the angle of the test piece to be tested can be adjusted.

[0006] Further, the torque transmission assembly includes a combined flow gearbox and a low-speed gear; the central shaft of the low-speed gear is a low-speed shaft; both ends of the low-speed shaft are fixed at the center inside the combined flow gearbox through bearings; one end of the low-speed shaft extends outside the combined flow gearbox housing and is connected to the test piece to be tested through a flange structure.

[0007] Further, the low-speed torque loading assembly includes a driving motor, a multi-stage planetary gearbox and a high-speed planetary shaft; the driving motor is fixedly connected to the multi-stage planetary gearbox through a flange and is integrally fixed on the combined flow gearbox housing; the multi-stage planetary gearbox is connected to the high-speed planetary shaft, and power is output to the high-speed planetary shaft through the driving motor; a high-speed planetary gear is fixedly connected to the high-speed planetary shaft and meshes with the low-speed gear.

[0008] Further, the output shaft of the planetary gearbox is fixedly connected to the high-speed planetary shaft through a flexible coupling.

[0009] Further, the low-speed torque loading assembly is provided with an even number of groups of eight or more, and is evenly distributed on both sides of the combined flow gearbox; the high-speed planetary gears of the even number of groups of eight or more of the low-speed torque loading assemblies are evenly arranged along the circumferential direction of the low-speed gear and mesh with the low-speed gear, and the driving motors and multi-stage planetary gearboxes of two adjacent high-speed planetary gears are distributed on both sides of the combined flow gearbox.

[0010] Further, the adjustment unit includes an overall base and two tilting oil cylinders; the overall base is integrally connected to the bottom of the combined flow gearbox; the lower part of the overall base is connected to the fixing unit through a hinge; the two tilting oil cylinders are distributed at both ends on one side of the overall base, and the tilting direction and angle of the overall base and the combined flow gearbox are adjusted through the telescopic movement of the tilting oil cylinders.

[0011] Further, the fixing unit includes a fixing base; four hinge seats are provided on the upper part of the fixing base; the overall base and the hinge seats on the fixing base are hinged through a standard pin.

[0012] Further, an auxiliary oil cylinder is provided inside the overall base for balancing the weight of the loading system.

[0013] Further, the two ends of the flexible coupling are respectively connected to the output shaft of the planetary gearbox and the high-speed planetary shaft by expansion sleeves.

[0014] Further, it also includes a high-precision encoder and a controller; the high-precision encoder is used for measuring rotational speed, angular acceleration, and torsional vibration, and cooperates with the controller to achieve synchronous control of multiple drive motors.

[0015] The beneficial effects of the present invention are:

[0016] A multi-motor combined flow drive torque loading system for fan main shaft testing according to the present invention realizes large speed ratio and large torque transmission by adopting the method of multiple drive motors + combined flow gearbox. This method can reduce the torque of a single drive motor and form a cost-effective solution.

[0017] A multi-stage planetary gearbox is connected in series to the output shaft of the drive motor to reduce the transmission ratio of the combined flow gearbox, further reduce the space size, and at the same time reduce the manufacturing difficulty;

[0018] At the connection between the output shaft of the multi-stage planetary gearbox and the high-speed planetary shaft, a flexible coupling is used, and at the same time, the high-speed planetary shaft is designed with flexibility, which can reduce gear impact and improve the load sharing performance of multiple planetary gears;

[0019] The inclination cylinder on the integral base can be used to adjust the angle, simulate the actual installation angle of the fan, and make the test results closer to the real situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 is a side view of the combined flow gearbox connecting the drive motor of the present invention;

[0022] Figure 3 is Figure 2 a schematic cross-sectional view of A-A;

[0023] Figure 4 is a schematic diagram of the structure of the present invention from another perspective;

[0024] Figure 5 is a schematic diagram of the structure of the low-speed torque loading component of the present invention;

[0025] Figure 6 is a schematic diagram of the low-speed gear structure of the present invention;

[0026] In the attached drawings: 1. Confluence gearbox; 2. Low-speed gear; 3. Low-speed shaft; 4. Bearing; 5. Flange structure; 6. Driving motor; 7. Multi-stage planetary gearbox; 8. High-speed planetary shaft; 9. High-speed planetary gear; 10. Flexible coupling; 11. Integral base; 12. Tilt cylinder; 13. Fixed base; 14. Hinge seat. Detailed implementation manners

[0027] The present invention will be further described in detail below with reference to the attached drawings and specific embodiments. To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the attached drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the attached drawings here can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present invention provided in the attached drawings below is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0028] It should be noted that like reference numerals and letters denote like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present invention. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance. In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging, but may be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but may be slightly inclined. In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "arranged", "installed", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] Embodiment:

[0030] As shown in the attached Figures 1 to 6As shown in the figure, a multi-motor confluence drive torque loading system for fan main shaft testing includes a confluence drive unit, which includes several low-speed torque loading components and a torque transmission component. The low-speed torque loading components act together on the torque transmission component. The small torques of several low-speed torque loading components are collected on the torque transmission component to achieve the output of low-speed large torque, which is transmitted to the test piece connected to the torque transmission component to complete the large torque test of the test piece. The confluence drive unit is connected to the fixing unit through an adjusting unit, which can adjust the angle of the test piece to simulate the working angle of the test piece under real conditions, and the test result is closer to the real situation. The fixing unit is fixed to the concrete foundation to improve the stability of the overall system. Specifically, the torque transmission component includes a confluence gearbox 1 and a low-speed gear 2. The central axis of the low-speed gear 2 is a low-speed shaft 3, which extends to both sides of the low-speed gear 2 respectively. Bearing 4 structures are symmetrically arranged on both sides, and the low-speed gear 2 is fixed at the central position of the confluence gearbox 1 through the bearing 4 structures. The low-speed shaft 3 of the low-speed gear 2 extends to the outside of the confluence gearbox 1 housing on one side and is connected to the test piece through a flange structure 5. Specifically, the low-speed torque loading component includes a drive motor 6, a multi-stage planetary gearbox 7 and a high-speed planetary shaft 8. The outer housing of the drive motor 6 and the outer housing of the multi-stage planetary gearbox 7 are fixedly connected through a flange structure 5. The output end of the drive motor 6 is fixedly connected to the input end of the multi-stage planetary gearbox 7, and the whole is fixed on one side of the confluence gearbox 1 housing. The output shaft of the multi-stage planetary gearbox 7 extends into the confluence gearbox 1 and is fixedly connected to the high-speed planetary shaft 8. The high-speed planetary shaft 8 is supported in the confluence gearbox 1 through a bearing 4 structure. A high-speed planetary gear 9 is connected to the high-speed planetary shaft 8, which meshes with the low-speed gear 2 to transmit the torque of the drive motor 6 to the low-speed gear 2. Multiple high-speed planetary gears 9 driven by multiple drive motors 6 are evenly meshed on the outer edge of the low-speed gear 2 to increase the total torque of the low-speed gear 2 and meet the test requirements of the test piece. Among them, the multi-stage planetary gearbox 7 further amplifies the output of the drive motor 6 step by step in terms of torque. When finally output to the low-speed gear 2, there is enough torque to meet the requirements of the test piece; the structure of the multi-stage planetary gearbox 7 is compact, and it can transmit a larger torque under the same volume. The multi-stage design can achieve a higher reduction ratio in a limited space, significantly improve the torque output, and thus reduce the space size of the overall system. The structure of the multi-stage planetary gearbox 7 is well-known to those skilled in the art and will not be elaborated here again.

[0031] Several low-speed torque loading components are specifically set to have eight or more even-numbered groups, which are evenly distributed on both sides of the confluence gearbox 1. In this embodiment, twelve groups are set, and the corresponding twelve high-speed planetary gears 9 are evenly distributed in the circumferential direction of the low-speed gear 2 and mesh with it. The driving motors 6 and multi-stage planetary gearboxes 7 connected by adjacent two low-speed gears 2 are respectively arranged on both sides of the housing of the confluence gearbox 1, so that the force on the confluence gearbox 1 is balanced and the risk of resonance is reduced. The twelve driving motors 6 respectively pass through the multi-stage planetary gearboxes 7 and high-speed planetary gears 9 connected thereto, reduce speed and increase torque, and are all transmitted to the low-speed gear 2 to achieve low-speed high-torque transmission. Multiple driving motors 6 act independently together, and a single driving motor 6 can be replaced modularly. When a certain structure of a certain group of low-speed torque loading components fails, part of the test can still continue, improving the reliability and service life of this system.

[0032] A high-precision encoder is provided on each driving motor 6 for measuring rotational speed, angular acceleration, and torsional vibration, and cooperating with the controller to achieve synchronous control of each driving motor 6, ensuring that the rotational speed and rotational direction of the high-speed planetary gear 9 are the same, guaranteeing the power transmission efficiency, and at the same time avoiding the uneven stress between gears caused by different rotational speeds, and even preventing the occurrence of damage.

[0033] The output shaft of the planetary gearbox is connected to the high-speed planetary shaft 8 through a flexible coupling 10. The two ends of the flexible coupling 10 are connected by expansion sleeves. The expansion sleeve connection provides a high-precision centering method and reduces the angular deviation during installation. And the flexible coupling 10 itself can compensate for a certain angular, axial or radial deviation. The combination of the two enables the elastic deformation of the coupling to absorb even a small phase angle error during the installation process, thus ensuring the correct meshing phase of the high-speed planetary gear 9 and the low-speed gear 2. The high-speed planetary shaft 8 is made of special materials, and the flexible design can reduce gear impact and improve the load sharing performance of multiple high-speed planetary gears 9. For example, materials such as titanium alloy and nickel-based alloy are used, which have both high strength and high damping characteristics and suppress vibration propagation.

[0034] According to the specific test load magnitude, the low-speed gear 2 can be designed as a series drive of multiple gears, which improves the strength of the low-speed gear 2 group composed of multiple gears while reducing the machining difficulty of the gears.

[0035] The adjusting unit includes an integral base 11 and two tilting oil cylinders 12, and the fixing unit includes a fixing base 13 which is fixed to the concrete foundation to ensure the overall stability. The integral base 11 is fixedly connected to the confluence gearbox 1 as a whole. Four hinge seats 14 on the fixing base 13 are evenly distributed at the four corners. At the bottom ends of both sides of the integral base 11, there are hinge seats 14 which are connected to the corresponding hinge seats 14 on the fixing base 13 through tilting pin shafts. At the bottom ends of both sides of the other side of the integral base 11, there are tilting oil cylinders 12. The cylinder body of the tilting oil cylinder 12 is fixedly connected to the integral base 11 through a flange structure 5. The telescopic piston rod of the tilting oil cylinder 12 is connected to the hinge seat 14 on the corresponding fixing base 13 through a tilting pin shaft. When the piston rod of one tilting oil cylinder 12 or both tilting oil cylinders 12 make telescopic movements, the integral base 11 and the confluence gearbox 1 can be driven to tilt relative to the fixing base 13. By controlling the telescopic length and controlling the operation of one tilting oil cylinder 12 or both tilting oil cylinders 12 working simultaneously, the tilting angle and direction can be controlled. Preferably, considering the specific test requirements and the structural stability, the adjustment range is limited to 5 - 13°.

[0036] An auxiliary oil cylinder is provided inside the integral base 11, which is used to balance the weight of the loading system and increase the support stiffness of the integral base 11. By connecting the auxiliary oil cylinder to an accumulator and a proportional throttle valve, an active damping system is formed. By adjusting the pressure in the oil cylinder chamber in real time, a damping force opposite to the vibration phase is generated.

[0037] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A multi-motor confluence drive torque loading system for wind turbine main shaft testing, characterized by: It includes a confluence drive unit, an adjustment unit and a fixing unit; the confluence drive unit includes a torque transmission component and several groups of low-speed torque loading components; a test piece is connected to the torque transmission component; several groups of low-speed torque loading components act together on the torque transmission component to complete the high torque output to the test piece; the confluence drive unit is connected to the fixing unit through the adjustment unit, and the angle of the test piece can be adjusted.

2. A multi-motor confluence drive torque loading system for wind turbine main shaft testing according to claim 1, characterized in that: The torque transmission assembly comprises a confluence gearbox (1) and a low-speed gear (2); the central axis of the low-speed gear (2) is a low-speed shaft (3); both ends of the low-speed shaft (3) are fixed to the center of the confluence gearbox (1) through bearings (4); one end of the low-speed shaft (3) extends to the outside of the housing of the confluence gearbox (1) and is connected to the test piece through a flange structure (5).

3. A multi-motor confluence drive torque loading system for wind turbine main shaft testing according to claim 2, characterized in that: The low-speed torque loading component comprises a driving motor (6), a multi-stage planetary gearbox (7) and a high-speed planetary shaft (8); the driving motor (6) and the multi-stage planetary gearbox (7) are fixedly connected via a flange and are integrally fixed to a housing of a confluence gearbox (1); the multi-stage planetary gearbox (7) is connected to the high-speed planetary shaft (8), and power is output to the high-speed planetary shaft (8) via the driving motor (6); a high-speed planetary gear (9) is fixedly connected to the high-speed planetary shaft (8) and meshes with a low-speed gear (2).

4. The multi-motor confluence drive torque loading system for wind turbine main shaft testing according to claim 3 is characterized in that: The output shaft of the planetary gearbox is fixedly connected to the high-speed planetary shaft (8) via a flexible coupling (10).

5. The multi-motor confluence drive torque loading system for wind turbine main shaft testing according to claim 4 is characterized in that: The low-speed torque loading components are arranged in eight or more even-numbered groups, which are evenly distributed on both sides of the confluence gearbox (1); the high-speed planetary gears (9) of the eight or more even-numbered groups of the low-speed torque loading components are evenly arranged along the circumference of the low-speed gear (2) and mesh with the low-speed gear (2), and the drive motors (6) and multi-stage planetary gearboxes (7) of two adjacent high-speed planetary gears (9) are distributed on both sides of the confluence gearbox (1).

6. The multi-motor confluence drive torque loading system for wind turbine main shaft testing according to claim 5 is characterized in that: The adjustment unit comprises an integral base (11) and two tilting cylinders (12); the integral base (11) is integrally connected to the bottom of a merging gear box (1); the lower part of the integral base (11) is connected to a fixing unit in an articulated manner; the two tilting cylinders (12) are distributed at two ends of one side of the integral base (11), and the tilting direction and angle of the integral base (11) and the merging gear box (1) are adjusted by the telescopic movement of the tilting cylinders (12).

7. The multi-motor confluence drive torque loading system for wind turbine main shaft testing according to claim 6 is characterized in that: The fixing unit comprises a fixing base (13); four hinge seats (14) are arranged on the upper part of the fixing base (13); the integral base (11) and the hinge seats (14) on the fixing base (13) are hingedly connected via standard pins.

8. The multi-motor confluence drive torque loading system for wind turbine main shaft testing according to claim 7 is characterized in that: An auxiliary oil cylinder is arranged inside the integral base (11) for balancing the weight of the loading system.

9. The multi-motor confluence drive torque loading system for wind turbine main shaft testing according to claim 8, characterized in that: The two ends of the flexible coupling (10) are respectively connected to the output shaft of the planetary gearbox and the high-speed planetary shaft (8) by means of expansion sleeves.

10. The multi-motor confluence drive torque loading system for wind turbine main shaft testing according to claim 9, characterized in that: It also includes a high-precision encoder and a controller; the high-precision encoder is used to measure the rotation speed, angular acceleration and torsional vibration, and cooperates with the controller to achieve synchronous control of multiple drive motors (6).

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