Rotor braking structure and semi-direct-drive wind driven generator

Abstract

The invention belongs to the technical field of wind driven generators, and relates to a rotor braking structure and a semi-direct-driven wind driven generator. On the basis of the existing technical scheme, a switching cylinder structure is omitted, and the brake disc is installed on the end face of the rotor support magnet yoke through the bolts. The inner circle of the rotor support magnet yoke is matched with the brake disc through the seam allowance, the brake disc can support the rotor support magnet yoke in the radial direction, and therefore rib plates evenly distributed on the circumference close to one side of the brake disc in the prior art can be omitted for the rotor support. According to the brake disc, the brake function is achieved through cooperation of the inner circle and the brake instead of cooperation of the outer circle and the brake, the axial rigidity of the rotor support magnet yoke is large, the axial rigidity of the brake disc can be effectively improved after the rotor support magnet yoke is connected with the brake disc, axial runout is improved, and assembly accuracy is improved. According to the scheme, switching cylinder installation is omitted, assembling switching matching is reduced, the assembling precision is improved, and the manufacturing cost of the generator is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of wind turbine generators and relates to a rotor braking structure and a semi-direct-drive wind turbine generator. Background Art

[0002] As one of the most mature, fastest-growing and most promising ways of generating electricity in the development and utilization of clean and renewable energy in the world today, wind power generation has received widespread attention. The shortcomings of traditional direct-drive wind turbines and doubly-fed wind turbines have seriously affected the development of the industry. In order to make more scientific and rational use of natural resources, improving the unit capacity and design and manufacturing technology of wind turbines has become an urgent problem to be solved in the development. As an integration of direct drive and doubly-fed technology routes, the semi-direct drive technology route takes into account the advantages of both. The system uses a single or two-stage gearbox to increase the speed. The motor speed is higher than that of direct drive, and the volume is greatly reduced. It is the main technical direction for the current development of wind turbines with higher power. Due to the competition in wind power, each main engine manufacturer requires to continuously reduce the cost of generators while ensuring reliability.

[0003] At present, the braking solutions used by various generator manufacturers on semi-direct drive generators are basically the same, such as Figure 4 As shown, the brake system is installed on the generator, and the generator is composed of a stator assembly, a rotor assembly and a rear cover 5 assembly. The brake 4 is installed on the brake 4 mounting interface set on the rear cover 5. The rear cover 5 is connected to the generator base 2 by bolts, and the base is connected to the gearbox end cover by bolts. The brake disc 3 is connected to the adapter tube 9 by bolts, and the adapter tube 9 is fixed to the flange 6 by bolts. The center of the flange 6 is connected to the output shaft of the gearbox, and the outer circle is connected to the rotor bracket 1. When the rotor assembly is in a rotating state, the rotor braking is achieved by starting the brake 4 brake body and the friction between the brake disc 3. However, since the brake disc 3 and the brake 4 have 7 assembly interfaces in the entire assembly dimension chain, involving multiple components, and the adapter tube 9 and the rear cover 5 have poor rigidity, the axial and radial runout of the brake disc 3 after the assembly is completed will not meet the assembly requirements; if the processing accuracy and structural rigidity are improved, the cost of the generator will increase. At the same time, during the high-speed rotation of the generator, due to large assembly deviations and insufficient structural rigidity, there is interference between the brake 4 and the brake disc 3. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and to provide a generator rotor braking structure and a semi-direct drive wind turbine.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A generator rotor braking structure, wherein a braking mechanism is arranged on a rotor support, and a brake is arranged on a rear end cover of a generator base, and the braking mechanism and the brake cooperate with each other to realize a braking function.

[0007] Furthermore, the brake mechanism is a brake disc, which is mounted on a horizontal end surface formed by the end surface of the rotor bracket yoke and the end surface of the magnetic pole, and the horizontal end surface is located close to the rear end cover, and the brake disc is connected to the horizontal end surface.

[0008] Furthermore, the rear end cover is stepped, and includes a first step end surface and a second step end surface, and the second step end surface is screwed to the side surface of the brake.

[0009] Furthermore, a first through hole is provided on the brake disc, and the first through hole is located near the outer edge of the brake disc. A second through hole is provided on the magnetic pole end surface, and the same magnetic pole pull rod is provided in the first through hole and the second through hole.

[0010] Furthermore, a T-shaped heat dissipation channel is circumferentially arranged on the brake disc, and the T-shaped heat dissipation channel includes an axial channel and a radial channel, both ends of the axial channel are connected to the external environment, the first end of the radial channel is connected to the axial channel, and the second end of the radial channel is connected to the external environment.

[0011] Furthermore, the brake disc is provided with a threaded hole for threadedly connecting the end face of the rotor bracket yoke.

[0012] Furthermore, the outer edge of the first step end surface is screwed to the generator base.

[0013] Furthermore, the brake mechanism is a brake ring formed by extending the rotor support yoke in a direction toward the rear end cover, and the side surface of the brake is connected to the inner circular surface of the rear end cover.

[0014] Furthermore, the brake body friction plate of the brake is an arc-shaped friction plate, and the size of the arc-shaped friction plate matches the inner and outer diameters of the brake ring.

[0015] The present invention also discloses a semi-direct drive wind turbine generator, comprising any one of the rotor braking structures described above.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention installs the brake disc on the end face of the rotor bracket yoke, which can improve the radial stiffness of the yoke and improve the axial runout of the brake disc. They can reinforce each other and improve the overall structural strength of the generator. In addition, the installation of the adapter tube is eliminated, the number of interface adapters is reduced, the accumulation of assembly errors is reduced, the weight of the generator is reduced, and the cost-reducing design of the generator is realized.

[0018] 2. The present invention improves the stress state of the rear end cover by shortening the distance between the brake mounting hole and the base flange, thereby avoiding the risk of excessive deformation during braking.

[0019] 3. The present invention can reduce the number of parts of the brake disc and the brake in the entire assembly dimension chain, and reduce the phenomenon that the axial and radial runout of the brake disc cannot meet the assembly requirements due to tolerance accumulation or insufficient assembly precision.

[0020] 4. The present invention utilizes the rigidity of the rotor support to improve the rigidity of the brake disc, thereby avoiding the interference between the brake disc and the brake due to insufficient rigidity when the brake disc rotates at high speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the present invention.

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 This is a schematic diagram of the structure of Example 1 of the present invention;

[0024] Figure 2 This is a schematic diagram of the partial structure of the brake disc of Example 1 of the present invention;

[0025] Figure 3 This is a schematic diagram of the structure of Example 2 of the present invention;

[0026] Figure 4 It is a structural schematic diagram of the prior art;

[0027] Figure 5 It is a schematic diagram of the brake disc structure in the present invention;

[0028] Figure 6 is a schematic cross-sectional view of a brake disc in the present invention;

[0029] Figure 7 Schematic diagram of the T-shaped heat dissipation channel inside the brake disc of the present invention.

[0030] Among them: 1 is the rotor bracket; 2 is the generator base; 3 is the brake disc; 3-1 is the quenching layer; 3-2 is the hot-sprayed zinc layer; 4 is the brake; 5 is the rear end cover; 6 is the flange; 7 is the horizontal end face; 7-1 is the connecting bolt; 7-2 is the pole pull rod; 7-3 is the magnetic steel pressure plate; 8 is the pole; 9 is the adapter tube; 10 is the magnet. DETAILED DESCRIPTION

[0031] Here, exemplary embodiments will be described in detail, and the embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples of devices consistent with some aspects of the present invention as detailed in the appended claims.

[0032] Example 1

[0033] like Figures 1-2 As shown, a generator rotor braking structure, the brake mechanism is arranged on the rotor support 1, the brake 4 is arranged on the rear end cover 5 of the generator base 2, and the brake mechanism and the brake 4 cooperate with each other to realize the braking function.

[0034] Furthermore, the brake mechanism is a brake disc 3, which is installed on a horizontal end surface 7 formed by the end surface of the rotor bracket yoke and the end surface of the magnetic pole 8. The horizontal end surface 7 is located close to the rear end cover 5, and the brake disc 3 is connected to the horizontal end surface 7.

[0035] Furthermore, the rear end cover 5 is stepped, and includes a first step end surface and a second step end surface, and the second step end surface is screwed to the side surface of the brake 4 .

[0036] Furthermore, a first through hole is provided on the brake disc 3, and the first through hole is located near the outer edge of the brake disc 3. A second through hole is provided on the end face of the magnetic pole 8, and the same magnetic pole pull rod 7-2 is provided in the first through hole and the second through hole.

[0037] Furthermore, the brake disc 3 is provided with a threaded hole for screwing the yoke end surface of the rotor bracket 1 .

[0038] Furthermore, the outer edge of the first step end face is screwed to the generator frame 2. Design principle of this solution: Based on the existing technical solution, this solution cancels the adapter tube structure and installs the brake disc 3 to the end face of the rotor bracket yoke by bolts. The inner circle of the rotor bracket yoke cooperates with the brake disc 3 through a stopper, and the brake disc 3 can support the rotor bracket yoke in the radial direction. Therefore, the rotor bracket 1 can cancel the rib plate evenly distributed on the circumference near the brake disc 3 in the prior art; specifically, a stopper is provided on the side of the rotor bracket close to the rear end cover, and an installation stopper is provided on the side of the brake disc and the rotor bracket installation surface. The stopper is an interference fit, and the brake disc is installed on the end face of the rotor bracket. The brake disc supports the rotor bracket in the radial direction. Since the stiffness of the rotor bracket meets the requirements under the support of the brake disc, the rib plate on the brake disc side of the rotor bracket can be cancelled.

[0039] like Figures 5-6As shown, axial circular holes are evenly arranged on the brake disc 3 or the brake ring. Preferably, the circular holes are staggered in inner and outer circles. A magnet 10 is installed in the circular hole. The upper and lower ends of the magnet 10 are at a certain distance from the surface of the brake disc 3 or the brake ring. A groove is formed at the end surface of the magnet on the surface of the brake disc 3, which is evenly distributed on the surface of the brake disc 3. Its main function is that when the brake disc 3 rotates at a high speed, a large amount of iron grinding will be generated under the braking action of the brake 4. The iron grinding will reach various parts of the generator cabin under the high-speed rotation of the brake disc 3. If the iron grinding enters the inside of the motor or the inside of the electric control cabinet, it will cause the winding short circuit and the motor to burn, and even cause a fire. Since a magnet is installed in the brake disc 3, the brake disc 3 will be magnetized, and the iron grinding generated during the braking process will be adsorbed on the surface of the brake disc 3. Since the magnet position has a large suction force, the iron grinding will mainly enter the groove. The maintenance personnel regularly clean the iron filings in the groove to ensure the long-term reliable operation of the motor.

[0040] like Figure 6 As shown, the generator operates in a high temperature and high humidity environment for a long time, and a hot-sprayed zinc layer 3-2 is provided on the surface of the brake disc 3, which can effectively improve the friction and anti-corrosion performance of the brake disc; a quenching layer 3-1 is provided on the surface of the brake disc 3 to the dotted line position in the upper figure, which can improve the surface hardness of the brake disc and reduce the damage to the brake disc during braking.

[0041] like Figure 7 As shown, T-shaped heat dissipation channels are evenly distributed in the circumferential direction of the brake disc 3, and the T-shaped heat dissipation channels include an axial channel and a radial channel. Both ends of the axial channel are connected to the external environment, the first end of the radial channel is connected to the axial channel, and the second end of the radial channel is connected to the external environment. When the brake disc 3 rotates at a high speed, under the action of centrifugal force, the air will flow in the direction of the arrow shown in the figure. When the brake disc 3 brakes, a large amount of heat will be generated, and the air will dissipate the heat according to the flow shown in the figure.

[0042] In addition, the brake disc 3 is changed from an outer circle cooperating with the brake 4 to an inner circle cooperating with the brake 4 to achieve the braking function. The rotor bracket yoke has a large axial stiffness. After being connected to the brake disc 3, the axial stiffness of the brake disc 3 can be effectively improved, thereby improving the axial runout and assembly accuracy. This solution eliminates the installation of the adapter tube, reduces assembly and transition cooperation, improves assembly accuracy, and reduces the manufacturing cost of the generator. The installation direction of the brake 4 is flipped 180° compared to the existing solution, and the installation surface of the brake 4 is 200mm shorter than the existing solution from the upper end surface, which improves the force assembly of the rear end cover 5. Reduce the phenomenon of excessive deformation of the rear end cover 5 and the brake disc 3 during braking.

[0043] like Figure 2As shown, compared with the existing products, the end face of the rotor yoke is equipped with a brake disc 3, which protrudes from the outer circle of the yoke. The outer circle of the brake disc 3 is provided with evenly distributed through holes in the circumferential direction for the installation of the pole pull rod. The brake disc 3 as a whole can replace the pole pressure plate structure of the existing product (the specific component is the magnetic steel pressure plate 7-3), between the brake disc 3 and the end face of the pole 8. Specifically, in the prior art, the pole pressure plate is fixed to the end face of the rotor bracket to press the pole, while the present invention reduces the inner circle of the pole pressure plate to form a brake disc structure, which is equivalent to the brake disc 3 and the pole pressure plate being an integrated structure, and having the functions of braking and pressing the pole at the same time.

[0044] Example 2

[0045] like Figure 3 As shown, based on Example 1, the difference between this embodiment and Example 1 is that the brake mechanism is a brake ring formed by extending the rotor support yoke in the direction toward the rear end cover 5, and the side surface of the brake 4 is connected to the inner circular surface of the rear end cover 5.

[0046] Furthermore, the brake body friction plate of the brake 4 is an arc-shaped friction plate, and the size of the arc-shaped friction plate matches the inner and outer diameters of the brake ring.

[0047] The present invention also provides a semi-direct drive wind turbine generator, comprising any of the above-mentioned rotor braking structures.

[0048] This embodiment is a further optimized design based on the embodiment 1. On the basis of the existing scheme, the adapter tube 9 and the brake disc 3 are cancelled, and the rear end cover 5 is further simplified. A certain length is reserved on the side of the rotor bracket yoke close to the rear end cover 5 for the processing of the brake ring. A brake 4 mounting hole is provided on the inner circular surface of the rear end cover 5. After the brake 4 is installed, it is rotated 90° compared with the existing scheme. The brake 4 brake body friction plate is designed in an arc shape, and the arc size needs to match the inner and outer diameters of the brake ring. The brake mounting seat is cancelled on the rear end cover 5, the distance between the installation position of the brake 4 and the connection flange of the base is shortened, the stress state is improved, the structure of the rear end cover 5 is simpler, the weight is reduced and the cost is saved. The brake ring and the rotor bracket 1 are integrated into a design to make the generator structure simpler. At the same time, the rigidity of the rotor bracket 1 is utilized to improve the strength of the brake ring and ensure that the assembly size of the brake ring meets the requirements. After the change, the space in the central area of ​​the generator is improved, which can be used for the arrangement of other product components and improve the utilization rate of the cabin space.

[0049] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0050] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A generator rotor braking structure, characterized in that: It comprises a brake mechanism, wherein the brake mechanism is arranged on a rotor support (1), and a brake (4) is arranged on a rear end cover (5) of a generator base (2). The brake mechanism and the brake (4) cooperate with each other to realize a braking function.

2. A generator rotor braking structure according to claim 1, characterized in that: The brake mechanism is a brake disc (3), and the brake disc (3) is mounted on a horizontal end surface (7) formed by the end surface of the rotor bracket yoke and the end surface of the magnetic pole (8), and the horizontal end surface (7) is located near the rear end cover (5), and the brake disc (3) is connected to the horizontal end surface (7).

3. A generator rotor braking structure according to claim 2, characterized in that: The rear end cover (5) is stepped, and comprises a first step end face and a second step end face, wherein the second step end face is screwed to the side face of the brake (4).

4. A generator rotor braking structure according to claim 3, characterized in that: The outer edge of the first step end surface is screwed to the generator base (2).

5. A generator rotor braking structure according to claim 2, characterized in that: The brake disc (3) is provided with a first through hole, the first through hole being located close to the outer edge of the brake disc (3), the end surface of the magnetic pole (8) is provided with a second through hole, and the same magnetic pole pull rod (7-2) is provided in the first through hole and the second through hole.

6. A generator rotor braking structure according to claim 2, characterized in that: A T-shaped heat dissipation channel is arranged on the brake disc (3) in the circumferential direction, and the T-shaped heat dissipation channel includes an axial channel and a radial channel, both ends of the axial channel are connected to the external environment, the first end of the radial channel is connected to the middle part of the axial channel, and the second end of the radial channel is connected to the external environment.

7. A generator rotor braking structure according to claim 2, characterized in that: The brake disc (3) is evenly provided with a plurality of circles of axial circular holes along the circumferential direction, and magnets are arranged in the axial circular holes.

8. The generator rotor braking structure according to claim 1, characterized in that: The brake mechanism is a brake ring formed by extending the rotor support yoke in a direction toward the rear end cover (5), and the side surface of the brake (4) is connected to the inner circular surface of the rear end cover (5).

9. A generator rotor braking structure according to claim 8, characterized in that: The brake body friction plate of the brake (4) is an arc-shaped friction plate, and the size of the arc-shaped friction plate matches the inner and outer diameters of the brake ring.

10. A semi-direct drive wind turbine, characterized in that: It comprises a rotor braking structure as claimed in any one of claims 1 to 9.

Images