A pitch bearing testing machine based on the internal force method and its usage method

Abstract

This invention belongs to the field of bearing testing technology, proposing a pitch bearing testing machine based on the internal force method and its usage method. It includes an upper loading cylinder, a floating hexagon, cylinder pins, a loading disk, a simulated blade root, a test bearing, a test bearing, a simulated blade root connector, a hub base, a lower loading cylinder, and an oblique loading cylinder. The simulated blade root connector has multiple connection ports spaced at equal angles. One end of the simulated blade root is connected to the connection port on the simulated blade root connector via the test bearing, and the other end is connected to the loading disk via the test bearing. The floating hexagon and hub base are respectively installed at both ends of the simulated blade root connector. The upper loading cylinder connects the floating hexagon and the loading disk via cylinder pins, and the lower loading cylinder and oblique loading cylinder are both connected to the hub base and the loading disk via cylinder pins. This invention utilizes the principle of mutual interaction and offsetting internal forces, eliminating the need for most of the machine base while accommodating various loading methods.

Description

Technical Field

[0001] This invention relates to the field of bearing testing technology, and in particular to a pitch bearing testing machine based on the internal force method and its usage method. Background Technology

[0002] Wind turbines operate in harsh environments, and pitch bearings, as key components of the pitch system, are directly connected to the blades and bear extremely complex loads. Current experimental devices for wind turbine pitch bearings in my country offer relatively simple simulations of bearing lifespan, load conditions, and load types, considering only a single load type, which has significant limitations. For example, although the specific implementation devices in patents "CN106017934A" and "CN205898456U" differ, they both simulate the actual load conditions of the bearing by applying a single radial force and a single axial force, which is highly limiting. Summary of the Invention

[0003] In view of this, the present invention provides a pitch bearing testing machine based on the internal force method and its usage method, which can perform experiments such as deformation measurement and relative deformation measurement between wheel hub and wheel hub bearing, and pressure measurement of lubricating oil or grease under various working conditions.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A pitch bearing testing machine based on the internal force method includes an upper loading section, a hub bearing mounting section, and a testing machine base. The upper loading section includes an upper loading cylinder 1, a floating hexagonal body 2, and a cylinder pin 11. The hub bearing mounting section includes a loading disk 3, a simulated blade root 4, a test bearing 5, a test bearing 6, and a simulated blade root connector 7. The testing machine base includes a hub base 8, a lower loading cylinder 9, an oblique loading cylinder 10, and a cylinder pin 11. Multiple connection ports are evenly spaced on the simulated blade root connector 7. One end of the blade root 4 is connected to the connection port on the simulated blade root connector 7 via a test bearing 5, and the other end is connected to the loading disk 3 via a test bearing 6. A floating hexagon 2 is installed at one end of the simulated blade root connector 7. An upper loading cylinder 1 is connected to the floating hexagon 2 and the loading disk 3 via cylinder pins 11. A hub base 8 is installed at the other end of the simulated blade root connector 7. A lower loading cylinder 9 and an inclined loading cylinder 10 are both connected to the hub base 8 and the loading disk 3 via cylinder pins 11. The lower loading cylinder 9 is located above the inclined loading cylinder 10. The test bearing 5 is installed between the simulated blade root 4 and the simulated blade root connector 7, and the test bearing 6 is installed between the loading disk 3 and the simulated blade root 4.

[0006] The number of upper loading cylinder 1, lower loading cylinder 9, and oblique loading cylinder 10 are all 6, and cylinder pin 11 is used in conjunction with the loading cylinder; the number of connection ports on the simulated blade root connector 7, the number of simulated blade root 4, and the number of loading disk 3 are all 3, and the test bearing 5 and the auxiliary bearing 6 are used according to actual needs; the upper loading cylinder 1 is evenly distributed on the three non-adjacent sides of the floating hexagon 2; the lower loading cylinder 9 and the oblique loading cylinder 10 are evenly distributed on the sides of the hub base 8.

[0007] In the hub bearing installation section, the test bearing 5 and the auxiliary bearing 6 on one or two simulated blade roots 4 are replaced with flanges for testing hub bearings in two directions or one direction.

[0008] A method for using a pitch bearing testing machine based on the internal force method is as follows: During operation, the upper loading cylinder 1 applies a thrust F1, the lower loading cylinder 9 applies a force F2, and the oblique loading cylinder 10 applies a tension F3. The overturning moment M of the test bearing 5 is then obtained by the following formula:

[0009] M = F1 × L1 + F2 × L2 + F3 × L3

[0010] Wherein, L1, L2, and L3 are the straight-line distances from the point of application of the thrust F1 applied by the upper loading cylinder to the center of the simulated blade root connector 7, the straight-line distances from the point of application of the force F2 applied by the lower loading cylinder to the center of the simulated blade root connector 7, and the straight-line distances from the point of application of the tension F3 applied by the oblique loading cylinder to the center of the simulated blade root connector 7, respectively.

[0011] The axial force Fa of the test bearing 5 was calculated using F1, F2, F3, and M.

[0012] Fa=F1-F2-F3×cosα

[0013] The radial force Fr of test bearing 5 is obtained by the following formula:

[0014] Fr=F3×sinα

[0015] Where α is the angle between the inclined loading cylinder 10 and the lower loading cylinder 9.

[0016] During operation, the upper loading cylinder 1 interacts with each other, and the forces of the upper loading cylinder 1 act on the floating hexagon 2 and cancel each other out. The forces of the lower loading cylinder 9 act on the hub base 8 and cancel each other out.

[0017] The beneficial effects of this invention are as follows: The pitch bearing testing machine based on the internal force method utilizes interacting internal forces to cancel each other out during operation, thus eliminating the need for a large portion of the machine base. Furthermore, the force exerted by the described cylinder mounting method can meet various loading conditions for pitch bearings up to 20MW. In addition, besides simultaneously conducting hub bearing experiments in three directions, this pitch bearing testing machine based on the internal force method can also test hub bearings in one or two directions, while flanges can be used to replace bearings in the other two or one directions. This significantly reduces the number of bearing experiments and thus lowers experimental costs. The premise of the pitch bearing testing machine based on the internal force method is that as long as the forces are balanced, any number of directions can be tested. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the pitch bearing testing machine based on the internal force method of the present invention.

[0019] Figure 2 This is a partial schematic diagram of the hub bearing mounting portion of the present invention;

[0020] Figure 3 This is a schematic diagram of the base of the testing machine of the present invention.

[0021] In the figure: 1-Upper loading cylinder; 2-Floating hexagon; 3-Loading disk; 4-Simulated blade root; 5-Test bearing; 6-Test bearing; 7-Simulated blade root connector; 8-Hub base; 9-Lower loading cylinder; 10-Oblique loading cylinder; 11-Cylinder pin. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, not all embodiments, and are not intended to limit the scope of the present invention. Therefore, all equivalent changes made to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention. Furthermore, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion regarding the concepts disclosed in the present invention.

[0023] The accompanying drawings show a schematic diagram of the structure according to an embodiment of the present invention. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations.

[0024] A pitch bearing testing machine based on the internal force method includes an upper loading section, a hub bearing mounting section, and a testing machine base. When designed for a 20MW hub, the pitch bearing testing machine based on the internal force method has an average hub diameter of approximately 6000mm and a weight of approximately 60-80 tons.

[0025] like Figure 1 As shown, the upper loading part includes an upper loading cylinder 1, a floating hexagon 2, and a cylinder pin 11.

[0026] During installation, the six upper loading cylinders 1 are evenly connected to the floating hexagon 2 via cylinder pins 11. When the upper loading cylinders 1 interact, their forces act on the floating hexagon 2 and cancel each other out.

[0027] like Figure 1 , Figure 2 As shown, the hub bearing mounting section includes a loading disk 3, a simulated blade root 4, a test bearing 5, a test bearing 6, and a simulated blade root connector 7. During installation, one end of the simulated blade root 4 is connected to the simulated blade root connector 7, which is mounted below the floating hexagon 2. The test bearing 5 is mounted between the loading disk 3 and the other end of the simulated blade root 4, while the test bearing 6 is mounted between the simulated blade root 4 and one end of the simulated blade root connector 7. The hub bearing mounting section consists of three groups, evenly distributed and connected to the simulated blade root connector 7. This pitch bearing testing machine based on the internal force method can simultaneously perform hub bearing experiments in three directions, or it can test hub bearings in one or two directions. For the other two directions or one direction, flanges can be used instead of bearings, which greatly reduces the number of bearing experiments and thus lowers the experimental cost.

[0028] like Figure 2 , Figure 3 As shown, the testing machine base includes a hub base 8, lower loading cylinders 9, oblique loading cylinders 10, and cylinder pins 11. During installation, the hub base 8 is mounted below the simulated blade root connector 7. The six lower loading cylinders 9 and six oblique loading cylinders 10 are evenly connected between the hub base 8 and the loading disk 3 via cylinder pins 11. The forces exerted by the lower loading cylinders 9 are all applied to the hub base 8 and cancel each other out. This eliminates the need for a large base, significantly reducing the overall weight and cost of the testing machine.

[0029] like Figure 1 , Figure 3As shown, the cylinder diameters of the upper loading cylinder 1, the lower loading cylinder 9, and the oblique loading cylinder 10 are all 600mm, and the strokes are all around 1500mm. When the maximum oil pressure of the hydraulic station is 16MPa, the maximum overturning moment can reach 85000KN·m, the radial load is 500 tons (adjustable), and the axial load is 200 tons (adjustable). The overturning moment direction is the windward direction of the fan, and the radial load is also the windward direction of the fan.

[0030] like Figure 1 As shown, the upper loading cylinder 1 applies a thrust F1, the lower loading cylinder 9 applies a pull F2, and the oblique loading cylinder 10 applies a pull F3. The overturning moment M of the test bearing 5 can then be obtained using the following formula:

[0031] M = F1 × L1 + F2 × L2 + F3 × L3

[0032] Wherein, L1, L2, and L3 are the straight-line distances from the upper loading cylinder applying thrust F1, the lower loading cylinder applying thrust F2, and the oblique loading cylinder applying tension F3 to the center of the simulated blade root connector 7, respectively.

[0033] The axial force Fa of the test bearing 5 was calculated using F1, F2, F3, and M.

[0034] Fa=F1-F2-F3×cosα

[0035] The radial force Fr of test bearing 5 is obtained by the following formula:

[0036] Fr=F3×sinα

[0037] Where α is the angle between the inclined loading cylinder 10 and the lower loading cylinder 9.

[0038] like Figure 1 As shown, during operation, after the pitch bearing testing machine based on the internal force method is installed, the upper loading cylinder system is hoisted onto the testing machine and fixed using the cylinder pin holes. After the external installation of the pitch bearing testing machine based on the internal force method is completed, the drive motor and gearbox inside the hub can be installed. Then, a load is applied to the pitch bearing testing machine based on the internal force method. The applied load is generally the rated load, and the specific load size can be set by the testing manufacturer according to their requirements. When the motor is running, it can move in an oscillating or rotating manner, and the movement time is also set by the manufacturer to conduct the bearing life test.

[0039] Since wind turbine manufacturers tend to perform oscillating load tests during hub bearing experiments, this machine uses a high-power servo motor for its drive motor. This allows for both oscillating and full-rotation tests, while also providing a wide speed range.

[0040] This experiment can perform measurements of wheel hub deformation, relative deformation of wheel hub bearings, temperature rise of wheel hub bearings, pressure of lubricating oil or grease, stress, and life under different rotational speeds and loads.

Claims

1. A pitch bearing testing machine based on the internal force method, characterized in that, The pitch bearing testing machine based on the internal force method includes an upper loading section, a hub bearing mounting section, and a testing machine base. The upper loading section includes an upper loading cylinder (1), a floating hexagon (2), and a cylinder pin (11). The hub bearing mounting section includes a loading plate (3), a simulated blade root (4), a test bearing (5), a test bearing (6), and a simulated blade root connector (7). The testing machine base includes a hub base (8), a lower loading cylinder (9), an oblique loading cylinder (10), and a cylinder pin (11). The simulated blade root connector (7) has multiple connection ports spaced at equal angles. One end of the simulated blade root (4) The test bearing (5) is connected to the connection port on the simulated blade root connector (7), and the other end is connected to the loading disk (3) through the test bearing (6); the floating hexagon (2) is installed on one end of the simulated blade root connector (7); the upper loading cylinder (1) is connected to the floating hexagon (2) and the loading disk (3) respectively through the cylinder pin (11); the hub base (8) is installed on the other end of the simulated blade root connector (7), and the lower loading cylinder (9) and the oblique loading cylinder (10) are connected to the hub base (8) and the loading disk (3) respectively through the cylinder pin (11); the lower loading cylinder (9) is located above the oblique loading cylinder (10).

2. The pitch bearing testing machine based on the internal force method according to claim 1, characterized in that, The number of the upper loading cylinder (1), the lower loading cylinder (9), and the oblique loading cylinder (10) are all 6; the number of the connection port on the simulated blade root connector (7), the simulated blade root (4), and the loading disk (3) are all 3; the upper loading cylinder (1) is evenly distributed on the three non-adjacent sides of the floating hexagon (2); the lower loading cylinder (9) and the oblique loading cylinder (10) are evenly distributed on the side of the hub base (8).

3. The pitch bearing testing machine based on the internal force method according to claim 2, characterized in that, In the hub bearing installation section, the test bearing (5) and the auxiliary bearing (6) on one or two simulated blade roots (4) are replaced with flanges for testing hub bearings in two directions or one direction.

4. A method for using a pitch bearing testing machine based on the internal force method, characterized in that, Specifically, during operation, the upper loading cylinder (1) applies a thrust F1, the lower loading cylinder (9) applies a force F2, and the oblique loading cylinder (10) applies a pulling force F3. The overturning moment M of the test bearing (5) is obtained by the following formula: M = F1 × L1 + F2 × L2 + F3 × L3 Wherein, L1, L2, and L3 are the straight-line distances from the point of application of the thrust F1 applied by the upper loading cylinder to the center of the simulated blade root connector (7), the straight-line distances from the point of application of the force F2 applied by the lower loading cylinder to the center of the simulated blade root connector (7), and the straight-line distances from the point of application of the tension F3 applied by the oblique loading cylinder to the center of the simulated blade root connector (7). The axial force Fa of the test bearing (5) is calculated using F1, F2, F3 and M; Fa=F1-F2-F3×cosα The radial force Fr of the test bearing (5) is obtained by the following formula: Fr=F3×sinα Where α is the angle between the inclined loading cylinder (10) and the lower loading cylinder (9).

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