A variable pitch mechanism based on a wind power generation experimental device

Abstract

The application relates to the technical field of wind power generation experiment equipment, and discloses a variable pitch mechanism based on a wind power generation experiment device, which comprises a hub, three groups of blades, a rotating seat for rotationally connecting the hub and the blades, a main shaft fixedly arranged at the rear end of the hub and connected with a generator, a central through hole arranged in the main shaft, a connecting support arranged at the rear end of the generator, an oil cylinder arranged on the connecting support, a push rod fixedly arranged at the shaft end of the oil cylinder and coaxially penetrating through the central through hole and extending into the hub, an adjusting seat arranged in the hub and connected with the front end of the push rod, three connecting arms uniformly arranged on the adjusting seat in the circumferential direction, the rear end of the connecting arm rotationally connected with the adjusting seat, a connecting rod arranged at the front end of the connecting arm, the connecting rod fixedly connected with the rotating seat, the other end of the connecting rod rotationally connected with the front end of the connecting arm, and the shaft ends of the connecting rod and the axis of the rotating seat eccentrically and parallelly distributed. The application has the beneficial effects of simple and stable structure and convenient maintenance.

Description

Technical Field

[0001] This invention relates to the field of wind power generation experimental equipment technology, and in particular to a pitch mechanism based on a wind power generation experimental device. Background Technology

[0002] Wind power generation equipment utilizes the power of wind in nature. The wind force acts on the blades, causing them to rotate, which in turn drives the rotor in the generator to generate electricity. Wind power is a clean energy source with great market potential, so many universities have established majors in wind power generation. To facilitate higher-level research and design of wind power generation equipment, a wind power generation experimental device is usually installed in the laboratory for teaching and research. The experimental device typically uses an electric motor to drive the blades. To study the effect of blade angle on power, the wind turbines currently in actual use usually employ an electric pitch mechanism. However, the electric pitch mechanism is complex in structure, costly, and heavy. Since wind power generation models are usually used in laboratories, the complex structure and heavy weight of the pitch mechanism will increase costs and make maintenance inconvenient. Summary of the Invention

[0003] To address the aforementioned problems in the prior art, this invention provides a pitch mechanism based on a wind power generation experimental device that is simple in structure, low in cost, and easier to use and maintain. It is particularly suitable for experimental teaching.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A pitch mechanism based on a wind power generation experimental device includes a hub and three sets of blades evenly distributed around the hub. The hub and blades are rotatably connected by a rotating seat. A main shaft connected to a generator is fixed at the rear end of the hub. A central through hole is provided in the main shaft. A connecting bracket is provided at the rear end of the generator. A hydraulic cylinder is provided on the connecting bracket. A push rod is fixed at the shaft end of the hydraulic cylinder. The push rod coaxially passes through the central hole and extends into the hub. The hub is provided with an adjustment seat connected to the front end of the push rod. The adjustment seat is circumferentially rotatable and axially limited to the push rod. Three connecting arms are evenly provided on the adjustment seat along the circumferential direction. The rear end of the connecting arm is rotatably connected to the adjustment seat. The front end of the connecting arm is provided with a connecting rod. The connecting rod is fixedly connected to the rotating seat. The other end of the connecting rod is rotatably connected to the front end of the connecting arm. The shaft end of the connecting rod is eccentrically parallel to the axis of the rotating seat.

[0005] The axial movement of the adjusting seat is converted into the rotational movement of the blades by the extension and retraction of the push rod driven by the hydraulic cylinder, thereby controlling the synchronous pitch change of the three blades. The overall structure is simple, lightweight, and very convenient to install and maintain.

[0006] Preferably, a connecting plate is fixedly provided at the front end of the main shaft, and the rear end of the hub is fixedly connected to the connecting plate through a connecting seat. The main shaft is provided with a bearing seat for connecting with the installation platform, and the main shaft passes through the bearing seat to form a rotatable connection.

[0007] Preferably, the connecting bracket includes a first connecting plate fixed to the rear end of the generator, a second connecting plate distributed parallel to the first connecting plate, and a guide rod for connecting the first connecting plate and the second connecting plate, with the hydraulic cylinder mounted on the second connecting plate.

[0008] Preferably, the guide rod is provided with a sliding seat, and the guide rod passes through the sliding seat to form a sliding connection. The push rod passes through the sliding seat and is fixedly connected to the sliding seat. The sliding seat is provided with a displacement sensor for detecting the displacement of the hydraulic cylinder shaft, and a sensing block is provided on the first connecting plate at a position corresponding to the displacement sensor. By cooperating with the displacement sensor and the sensing block, the extension and retraction of the hydraulic cylinder can be precisely controlled, thereby achieving precise pitch control.

[0009] Preferably, the bearing seat is fixed with a detection disc coaxially distributed with the connecting disc, the connecting disc is provided with a plurality of pressure detection components evenly distributed circumferentially, one end of the pressure detection component is elastically abutting against the detection disc, and the generator is provided with an alarm. The alarm will sound when the difference between the maximum and minimum values ​​of the pressure detection components exceeds a preset value. Normally, the detection values ​​of each pressure detection component are equal or very close. However, when the angles of the three sets of blades are inconsistent (due to a malfunction causing some blades to fail to pitch synchronously), the main shaft experiences uneven force and undergoes torsional deformation on one side. This will significantly increase the difference in the pressure detection values, triggering an alarm to remind operators to stop the machine for maintenance.

[0010] Preferably, the pressure detection assembly includes a slide rod fixed on a connecting plate and a slide sleeve sleeved on the outside of the slide rod. A pressure sensor sleeved on the outside of the slide rod is fixed on the connecting plate. An elastic element is provided between the detection end of the pressure sensor and the slide sleeve. The outer end of the slide sleeve abuts against the detection plate.

[0011] Preferably, the edge of the detection disc is provided with a conical surface, and the end of the sliding sleeve is provided with a conical wheel that elastically abuts against the conical surface.

[0012] Preferably, the spindle is driven to rotate by a motor, a gearbox is provided between the motor and the spindle, a brake disc is fixed on the input shaft of the gearbox, and two sets of hydraulic brake assemblies are provided on the brake disc; When the difference between the maximum and minimum values ​​of the pressure detection component is greater than a preset value, the hydraulic brake component applies the brakes.

[0013] Preferably, the hub has a spherical structure, and a maintenance window is provided at the front end of the hub, with a transparent cover plate at the maintenance window. The operation of the pitch mechanism can be clearly seen through the transparent cover plate.

[0014] Therefore, the present invention has the following beneficial effects: (1) The pitch mechanism has a simple and stable structure, low cost, and more convenient subsequent maintenance; (2) It is safer to use. When the angle of any blade is inconsistent and causes the main shaft to deform, the pressure change detected by the pressure detection component will trigger an alarm. At the same time, the hydraulic brake will be used to prevent the main shaft from breaking due to uneven force. Attached Figure Description

[0015] Figure 1 for Figure 1 This is a schematic diagram of one structure of the present invention.

[0016] Figure 2 for Figure 1 Another perspective view.

[0017] Figure 3 for Figure 1 Top view.

[0018] Figure 4 for Figure 1 A magnified view of a portion of point A in the middle.

[0019] Figure 5 for Figure 3 Sectional view at point BB.

[0020] Figure 6 This is a schematic diagram showing the connection between the hub, blades, and main shaft.

[0021] Figure 7 for Figure 6 A partial exploded view.

[0022] Figure 8 This is a schematic diagram of the structure and installation of the pressure detection component.

[0023] Figure 9 This is a schematic diagram of the internal structure of a wheel hub. Figure 10 This is a schematic diagram of the hydraulic circuit control principle for hydraulic cylinders and hydraulic brake components.

[0024] In the figure: hub 10, adjusting seat 100, connecting arm 101, connecting rod 102, connecting seat 103, transparent cover plate 104, blade 11, rotating seat 12, generator 13, mounting platform 14, shaft seat 15, detection disc 16, conical surface 160, motor 17, gearbox 18, input shaft 180, brake disc 19, hydraulic brake assembly 190, main shaft 20, connecting disc 21, central through hole 200, pressure detection assembly 22, slide rod 220, sliding sleeve 221, conical wheel 2210, pressure sensor 222, elastic element 223, protective cover 224, connecting bracket 30, first connecting plate 300, second connecting plate 301, guide rod 302, sliding seat 303, displacement sensor 31, sensing block 32, oil cylinder 40, push rod 41. Detailed Implementation

[0025] To make the technical problems to be solved, the technical solutions, and the beneficial technical effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and several exemplary embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0026] It should be understood that the terms "first," "second," etc., used herein are for descriptive purposes only and should not be construed as indicating or implying relative importance, nor should they be construed as implicitly specifying the number of technical features indicated. Features specified as "first" or "second" may expressly or implicitly indicate that at least one of those features is included.

[0027] like Figures 1-9 The pitch mechanism shown is based on a wind power generation experimental device and includes a hub 10 and three sets of blades 11 evenly distributed around the circumference of the hub 10. The hub 10 and the blades 11 are rotatably connected by a rotating seat 12. A main shaft 20 connected to a generator 13 is fixedly mounted at the rear end of the hub 10. The main shaft 20 has a central through hole 200. A connecting bracket 30 is mounted at the rear end of the generator 13. A hydraulic cylinder 40 is mounted on the connecting bracket 30. A push rod 41 is fixedly mounted at the shaft end of the hydraulic cylinder 40. The push rod 41 coaxially passes through the central hole and extends into the hub 10. Inside the hub 10, there is an adjusting seat 100 connected to the front end of the push rod 41. The adjusting seat 100 is circumferentially rotatable and axially limited to the push rod 41. Three connecting arms 101 are evenly arranged along the circumferential direction on the adjusting seat 100. The rear end of the connecting arm 101 is rotatably connected to the adjusting seat 100. The front end of the connecting arm 101 is provided with a connecting rod 1102. The connecting rod 102 is fixedly connected to the rotating seat 12. The other end of the connecting rod 102 is rotatably connected to the front end of the connecting arm 101. The shaft end of the connecting rod 102 is eccentrically parallel to the axis of the rotating seat 12.

[0028] The hub 10 has a spherical structure, and the front end of the hub 10 is provided with an inspection window, and a transparent cover plate 104 is provided at the inspection window.

[0029] The front end of the spindle 20 is fixedly provided with a connecting plate 21, and the rear end of the hub 10 is fixedly connected to the connecting plate 21 through a connecting seat 103. The spindle 20 is provided with a bearing seat 15 for connecting with the mounting platform 14, and the spindle 20 passes through the bearing seat 15 to form a rotatable connection.

[0030] The connecting bracket 30 includes a first connecting plate 300 fixed to the rear end of the generator 13, a second connecting plate 301 distributed parallel to the first connecting plate 300, a guide rod 302 for connecting the first connecting plate 300 and the second connecting plate 301, and a hydraulic cylinder 40 mounted on the second connecting plate 301.

[0031] A sliding seat 303 is provided on the guide rod 302, and the guide rod 302 passes through the sliding seat 303 to form a sliding connection. The push rod 41 passes through the sliding seat 303 and is fixedly connected to the sliding seat 303. A displacement sensor 31 for detecting the displacement of the hydraulic cylinder 40 shaft is provided on the sliding seat 303. A sensing block 32 is provided on the first connecting plate 300 at a position corresponding to the displacement sensor. In this embodiment, the displacement sensor 31 is a laser reflection sensor.

[0032] A detection disk 16 coaxially distributed with the connecting disk 21 is fixed on the bearing seat 15. Several pressure detection components 22 are evenly distributed along the circumference on the connecting disk 21. One end of the pressure detection component 22 is elastically abutted against the detection disk 16. An alarm is provided on the generator 13. The pressure detection assembly 22 includes a slide rod 220 fixed on the connecting plate 21 and a sliding sleeve 221 sleeved on the outside of the slide rod 220. A pressure sensor 222 sleeved on the outside of the slide rod 220 is fixed on the connecting plate 21. An elastic element 223 is provided between the detection end of the pressure sensor 222 and the sliding sleeve 221. The outer end of the sliding sleeve 221 abuts against the detection plate 16. In this embodiment, the elastic element is configured as a compression spring. A conical surface 160 is provided at the edge of the detection plate 16. A conical wheel 2210 elastically abuts against the conical surface is provided at the end of the sliding sleeve 221. The main shaft 20 is driven to rotate by a motor 17. A gearbox 18 is provided between the motor 17 and the main shaft 20. A brake disc 19 is fixed on the input shaft 180 of the gearbox. Two sets of hydraulic brake assemblies 190 are provided on the brake disc. When the difference between the maximum and minimum values ​​of the pressure detection component 22 exceeds a preset value, the alarm sounds, and the hydraulic brake component 190 applies the brakes simultaneously. A protective cover 224 is provided on the outside of the connecting plate.

[0033] Referring to the accompanying drawings, the principle of this invention is as follows: When pitch adjustment is required, the extension and retraction of the push rod is driven by the hydraulic cylinder, which in turn drives the axial movement of the adjusting seat. This, in turn, drives the three sets of connecting arms and connecting rods to rotate the three sets of rotating seats simultaneously, thereby driving the blades to rotate. In this embodiment, the blade rotation range is between -5° and +88°. During the process of the hub driving the blades to rotate, when the difference between the maximum and minimum values ​​of the pressure sensor in the pressure detection component 22 is greater than a preset value, the alarm sounds, and at the same time, the hydraulic brake component applies braking, thereby preventing the main shaft from breaking due to axial torsion and providing a safety protection function.

[0034] The extension and retraction of the hydraulic cylinder and the operation of the hydraulic brake assembly are achieved through, for example... Figure 10 The oil circuit shown is realized. Figure 10 In this configuration, K1 is a proportional flow control valve, K2, K4, and K5 are two-position three-way solenoid valves, K3 is a two-position on / off solenoid valve, S1 is a throttle valve, S2 is a hydraulically controlled check valve (the liquid flow direction of S2 can be adjusted via K4), S3 is an accumulator, S5 is an oil pump, and S4 is a safety valve; the above components are arranged according to... Figure 10 The oil circuit shown is connected to the oil cylinder 40 and the hydraulic brake assembly 190.

[0035] During normal operation (without adjusting the blades), the pressurized oil passes through S5 and K2 and then enters K1 (at this time, the P port of K1 is in the blocked state). When the pitch is adjusted to +88°, ports P and B in K1 are connected, ports A and T are connected, and ports P and A in K2 are connected. The pressurized oil passes through S5, K2 (port P), K2 (port A), K1 (port P), K1 (port B), S2, and cylinder 40 (right chamber) in sequence. The oil in cylinder 40 (left chamber) flows into the oil tank after passing through K1 (port A) and K1 (port T). During this process, the piston in the cylinder moves to the left, the push rod retracts, and the blade rotates to adjust the pitch in the +88° direction. When pitching in the -5° direction, port P in K1 is connected to port A, port B is connected to port T, and port P in K2 is connected to port A. The pressurized oil passes through S5, K2 (port P), K2 (port A), K1 (port P), K1 (port A), and cylinder 40 (left chamber) in sequence. The oil in cylinder 40 (right chamber) flows into the oil tank after passing through S2, K1 (port B), and K1 (port T). When the difference between the maximum and minimum values ​​of the pressure sensor in the pressure detection assembly 22 is greater than the preset value, an emergency shutdown is required (or other faults may require an emergency shutdown): Port B in K1 is disconnected, Port P in K2 is connected to Port B, K3 is opened, and Port P in K5 is connected to Port A; at this time, the pressure oil passes through S5, K2 (Port P), K2 (Port B), S1, and cylinder 40 (left chamber) in sequence. The oil in cylinder 40 (right chamber) passes through S2, K3, K5 (Port P), and K5 (Port A) before entering the hydraulic brake assembly 190 to achieve braking.

[0036] In the description of this invention, it should be understood that the directions or positional relationships indicated by up, down, left, right, inner end, outer end, one end, and the other end are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the purpose of more clearly describing the technical solutions of this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as limiting this invention.

[0037] Although specific embodiments of the invention have been described in detail herein, they are given for illustrative purposes only and should not be construed as limiting the scope of the invention. Various substitutions, alterations, and modifications can be conceived without departing from the spirit and scope of the invention.

Claims

1. A pitch mechanism based on a wind power generation experimental device, comprising a hub and three sets of blades evenly distributed along the circumference of the hub, wherein the hub and the blades are rotatably connected via a rotating base, and a main shaft connected to a generator is fixedly mounted at the rear end of the hub, characterized in that, The main shaft has a central through hole, the rear end of the generator has a connecting bracket, the connecting bracket has a hydraulic cylinder, the shaft end of the hydraulic cylinder has a push rod fixedly attached, and the push rod coaxially passes through the central hole and extends into the hub. The hub is provided with an adjustment seat connected to the front end of the push rod. The adjustment seat is circumferentially rotatable and axially limited to the push rod. Three connecting arms are evenly provided on the adjustment seat along the circumferential direction. The rear end of the connecting arm is rotatably connected to the adjustment seat. The front end of the connecting arm is provided with a connecting rod. The connecting rod is fixedly connected to the rotating seat. The other end of the connecting rod is rotatably connected to the front end of the connecting arm. The shaft end of the connecting rod is eccentrically parallel to the axis of the rotating seat. The front end of the main shaft is fixedly provided with a connecting plate, and the rear end of the hub is fixedly connected to the connecting plate through a connecting seat. The main shaft is provided with a bearing seat for connecting with the installation platform, and the main shaft passes through the bearing seat to form a rotatable connection. The shaft seat is fixed with a detection disc coaxially distributed with the connecting disc. The connecting disc is provided with a plurality of pressure detection components evenly distributed along the circumference. One end of the pressure detection component is elastically abutted against the detection disc. The generator is provided with an alarm. When the difference between the maximum and minimum values ​​of the pressure detection components is greater than a preset value, the alarm will sound an alarm. The pressure detection assembly includes a slide rod fixed on a connecting plate and a slide sleeve sleeved on the outside of the slide rod. A pressure sensor sleeved on the outside of the slide rod is fixed on the connecting plate. An elastic element is provided between the detection end of the pressure sensor and the slide sleeve. The outer end of the slide sleeve abuts against the detection plate. The edge of the detection disc is provided with a conical surface, and the end of the sliding sleeve is provided with a conical wheel that elastically abuts against the conical surface; the main shaft is driven to rotate by a motor, and a gearbox is provided between the motor and the main shaft. A brake disc is fixed on the input shaft of the gearbox, and two sets of hydraulic brake assemblies are provided on the brake disc; when the difference between the maximum and minimum values ​​of the pressure detection assembly is greater than a preset value, the hydraulic brake assembly brakes.

2. The pitch mechanism based on the wind power generation experimental device according to claim 1, characterized in that, The connecting bracket includes a first connecting plate fixed to the rear end of the generator, a second connecting plate distributed parallel to the first connecting plate, and a guide rod for connecting the first connecting plate and the second connecting plate. The hydraulic cylinder is mounted on the second connecting plate.

3. The pitch mechanism based on the wind power generation experimental device according to claim 2, characterized in that, The guide rod is provided with a sliding seat, and the guide rod passes through the sliding seat to form a sliding connection. The push rod passes through the sliding seat and is fixedly connected to the sliding seat. The sliding seat is provided with a displacement sensor for detecting the displacement of the cylinder shaft. The first connecting plate is provided with a sensing block at the corresponding position of the displacement sensor.

4. The pitch mechanism based on the wind power generation experimental device according to claim 1, characterized in that, The hub has a spherical structure, and an inspection window is provided at the front end of the hub. A transparent cover is provided at the inspection window.

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