Friction drive system and wind turbine generator set

Abstract

The present invention provides a friction drive system and a wind turbine generator set. The friction drive system includes: a support ring; a drive ring that provides a driving force; at least one friction wheel motor assembly assembled between the support ring and the drive ring, each friction wheel motor assembly including a motor and a friction wheel, the friction wheel being fixed to the motor shaft of the motor, wherein the friction wheel is in frictional contact with the drive ring, and under the drive of the drive ring, the friction wheel rotates due to the frictional force of the drive ring. According to the friction drive system of the present invention, by using the friction wheel for power transmission, compared with gear transmission, the design, manufacturing and operation and maintenance costs can be greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine generators, and more particularly, to a friction drive system and a wind turbine generator set. Background Art

[0002] A wind turbine generator set is a power machine that converts wind energy into mechanical energy. A traditional wind turbine generator set consists of a single generator. The impeller drives the generator via a main mechanical transmission chain to convert wind energy into electrical energy. The rated power of the generator is usually between several megawatts and more than a dozen megawatts. Therefore, the volume of each main component in the entire system is large, the weight is heavy, and the cost is high.

[0003] For a direct drive system, the main shaft is directly connected to the generator. The main shaft bearing not only has to support the impeller hub and bear the load from the impeller, but also has to support the generator rotor to ensure the designed clearance between the generator rotor and the stator. Therefore, the load on the main shaft bearing is large and it is prone to failure.

[0004] For a semi-direct drive system, the main shaft is connected to the generator through a speed increasing gearbox. To ensure the meshing quality between the gears in the gearbox, a strict geometric positional relationship also needs to be maintained between the main shaft and the input end of the gearbox. This poses very high requirements on the support stiffness of the main shaft system bearings. This results in the bearings being "over-designed", with further increased dimensions, heavy weight, and a superlinear increase in cost.

[0005] In addition, this structure of one tower and one machine is not conducive to the full utilization of wind energy and is not convenient for the modular design of the fan system. This trend becomes more prominent with the enlargement of wind turbine generator sets. Summary of the Invention

[0006] The object of the present invention is to provide a friction drive system and a wind turbine generator set that can significantly reduce the design, manufacturing, and operation and maintenance costs compared with gear transmission.

[0007] The object of the present invention is to provide a friction drive system and a wind turbine generator set that can effectively reduce the cost of the fan system and facilitate the modular design of the system.

[0008] The object of the present invention is to provide a friction drive system and a wind turbine generator set that can improve the utilization rate of wind energy.

[0009] According to one aspect of the present invention, there is provided a friction drive system, which may include: a support ring; a drive ring that provides a driving force; at least one friction wheel motor assembly assembled between the support ring and the drive ring, each friction wheel motor assembly including a motor and a friction wheel, the friction wheel being fixed to the motor shaft of the motor, wherein the friction wheel is in frictional contact with the drive ring, and driven by the drive ring, the friction wheel rotates under the frictional force of the drive ring. According to the friction drive system of the present invention, by using the friction wheel for power transmission, compared with gear transmission, the design, manufacturing and operation and maintenance costs can be greatly reduced.

[0010] Optionally, the friction drive system may include a plurality of the friction wheel motor assemblies, and the plurality of friction wheel motor assemblies are circumferentially distributed along the support ring and the drive ring. According to the friction drive system of the present invention, by replacing a high-power central generating set with a plurality of distributed generating sets for power generation, modular design and assembly can be achieved, and the number of actually operating generating sets can be determined in real time according to wind energy resources to improve the utilization rate of wind energy.

[0011] Optionally, the support ring and the drive ring may be coaxially arranged.

[0012] Optionally, the support ring may be arranged on the radially outer side or the radially inner side of the drive ring.

[0013] Optionally, the motor shaft is parallel to the axial directions of the support ring and the drive ring.

[0014] Optionally, the friction drive system may include an automatic loading device, and the automatic loading device makes the normal pressure received by the friction wheel increase as the frictional force increases.

[0015] Optionally, the automatic loading device is provided on each friction wheel motor assembly.

[0016] Optionally, the automatic loading device includes a swing arm mechanism, the swing arm mechanism connects the friction wheel motor assembly and the support ring, and driven by the drive ring, the friction wheel motor assembly and the swing arm mechanism swing relative to the support ring.

[0017] Optionally, the automatic loading device further includes a compression spring installed on the support ring, and the compression spring acts on the swing arm mechanism so that the friction wheel presses against the drive ring.

[0018] Optionally, the friction drive system satisfies Equation 1 or a friction self-locking condition equivalent to Equation 1:

[0019]

[0020] Wherein, α is the included angle between the connecting line OA from the center A of the friction wheel and the motor shaft to the driving center O of the driving ring and the vertical line OC at the driving center O, β is the included angle between the connecting line AB from the center A to the swinging center B of the swing arm mechanism and the connecting line OA, mg is the component of the total weight of the friction wheel motor assembly in the direction of the vertical line OC, Q is the total normal contact pressure between the friction wheel and the driving ring, and μ is the contact friction coefficient between the friction wheel and the driving ring.

[0021] Optionally, the friction self-locking condition equivalent to Equation 1 includes Equation 2:

[0022]

[0023] Wherein, F f is the tangential frictional force between the friction wheel and the driving ring.

[0024] Optionally, according to the included angle α of the friction wheel motor assembly, at least one of the effective length L of the swing arm of the swing arm mechanism and the distance OB from the swinging center B of the swing arm mechanism to the driving center O is adjusted so that each friction wheel motor assembly satisfies Equation 1 or Equation 2, and the effective length L of the swing arm is the distance between the swinging center line of the swing arm mechanism and the center line of the motor shaft.

[0025] Optionally, the friction drive system is placed such that the axes of the support ring and the driving ring are perpendicular to the horizontal plane, and the friction drive system satisfies the friction self-locking condition of Equation 3:

[0026] tanβ≤μ (3)

[0027] Wherein, β is the included angle between the connecting line AB from the center A of the motor shaft to the swinging center B of the swing arm mechanism and the connecting line OA from the center A of the motor shaft to the driving center O of the driving ring, and μ is the contact friction coefficient between the friction wheel and the driving ring.

[0028] Optionally, the swing arm mechanism includes two swing arms mounted on the motor, the two swing arms are parallel to each other, the swing arms are connected to the support ring through connectors, and can swing relative to the support ring.

[0029] Optionally, the motor shaft extends from both sides of the motor, at least one of the friction wheels is mounted on each motor shaft, the driving ring includes two raceways, and the two raceways are respectively in contact with the friction wheels on both sides of the motor.

[0030] Optionally, the driving ring includes an isolation groove provided between the two raceways and corresponding to the motor, and the isolation groove is concave relative to the two raceways to be spaced apart from the motor.

[0031] Optionally, the driving ring and / or the support ring are assembled by at least one section of annular components.

[0032] According to another aspect of the present invention, there is provided a wind power generating set, which includes the friction drive system as described above.

[0033] Optionally, the friction drive system is arranged such that the axes of the support ring and the driving ring are parallel or perpendicular to the horizontal plane, the support ring is connected to a fixed component within the wind power generating set, and the driving ring is driven by the impeller main shaft of the wind power generating set.

[0034] Optionally, the friction drive system is arranged such that the axes of the support ring and the driving ring are parallel to the horizontal plane, the support ring is connected to the base or fixed shaft of the wind power generating set, and the driving ring is mounted on the impeller main shaft.

[0035] Optionally, the friction drive system is arranged such that the axes of the support ring and the driving ring are perpendicular to the horizontal plane, the support ring is connected to the tower or flange of the wind power generating set, and the impeller main shaft transmits the driving force to the driving ring through a steering gear.

[0036] According to the friction drive system of the present invention, by using friction wheels for power transmission, compared with gear transmission, the design, manufacturing and operation and maintenance costs can be significantly reduced.

[0037] According to the friction drive system of the present invention, compared with the direct drive system in the prior art, the load on the main shaft bearing is small and it is not easy to fail.

[0038] According to the friction drive system of the present invention, multiple distributed generating sets can be used to replace a high-power central generating set for power generation, modular design and assembly can be realized, and the number of actually operating generating sets can be determined in real time according to wind resources to improve the utilization rate of wind energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Through the following detailed description in conjunction with the drawings, the above and other objects, features and advantages of the present invention will become clearer, wherein:

[0040] Figure 1 is a schematic diagram of a friction drive system according to an embodiment of the present invention;

[0041] Figure 2 is a schematic diagram of a part of a friction drive system according to an embodiment of the present invention;

[0042] Figure 3 is an exploded view of a friction drive system according to an embodiment of the present invention;

[0043] Figure 4 Schematic diagrams of a friction wheel motor assembly and an automatic loading device according to an embodiment of the present invention;

[0044] Figure 5 Schematic diagrams of a motor and an automatic loading device according to an embodiment of the present invention;

[0045] Figure 6 Schematic diagram of a part of a support ring according to an embodiment of the present invention;

[0046] Figure 7 Schematic diagram of a part of a drive ring according to an embodiment of the present invention;

[0047] Figure 8 Schematic diagram of the working principle of a friction drive system according to an embodiment of the present invention;

[0048] Figure 9 Schematic diagram of the working principle of a friction drive system according to another embodiment of the present invention.

[0049] In the drawings: 100 is a friction drive system, 10 is a support ring, 20 is a drive ring, 30 is a friction wheel motor assembly, 11 is a pin hole, 21 is a raceway, 22 is an isolation groove, 31 is a motor, 31a is a motor housing, 31b is a motor shaft, 32 is a friction wheel, 40 is a swing arm mechanism, 41 is a swing arm, 42 is a positioning pin hole, and 50 is a compression spring. Detailed Embodiments

[0050] Hereinafter, reference will be made to Figures 1 to 9 Describe a friction drive system according to an embodiment of the present invention.

[0051] As Figures 1 to 5 shown, a friction drive system 100 according to an embodiment of the present invention includes: a support ring 10; a drive ring 20 that provides a driving force; at least one friction wheel motor assembly 30 assembled between the support ring 10 and the drive ring 20, and each friction wheel motor assembly 30 includes a motor 31 and a friction wheel 32, and the friction wheel 32 is fixed to the motor shaft 31b of the motor 31. The friction wheel 32 is in frictional contact with the drive ring 20, and under the drive of the drive ring 20, the friction wheel 32 rotates by the frictional force of the drive ring 20.

[0052] As Figures 1 to 3 shown, the friction wheel motor assembly 30 can be assembled between the support ring 10 and the drive ring 20. The support ring 10 can act as a support for fixing the friction wheel motor assembly 30. The drive ring 20 can provide a driving force for the friction wheel motor assembly 30.

[0053] As Figure 4As shown, the friction wheel motor assembly 30 may include a motor 31 and a friction wheel 32, and the friction wheel 32 is fixed to the motor shaft 31b of the motor 31. As Figure 2 shown, the friction wheel 32 is in frictional contact with the drive ring 20. Driven by the drive ring 20, the friction wheel 32 rotates under the frictional force of the drive ring 20. Since the motor shaft 31b is fixedly connected to the friction wheel 32, when the friction wheel 32 rotates, the motor shaft 31b also rotates, thereby driving the motor 31 to generate electricity.

[0054] According to an embodiment of the present invention, by using a friction wheel for power transmission, compared with gear transmission, the design, manufacturing, and operation and maintenance costs can be significantly reduced.

[0055] According to an embodiment of the present invention, as Figure 1 and Figure 3 shown, the friction drive system 100 may include a plurality of friction wheel motor assemblies 30. The plurality of friction wheel motor assemblies 30 may be circumferentially distributed along the support ring 10 and the drive ring 20.

[0056] That is to say, according to an embodiment of the present invention, one high-power central generator set can be replaced by a plurality of distributed generator sets (i.e., a plurality of friction wheel motor assemblies 30) for power generation, modular design and assembly can be achieved, and the number of actually operating generator sets can be determined in real time according to wind resources to ensure the maximum utilization of wind energy.

[0057] According to an embodiment of the present invention, the number of friction wheel motor assemblies 30 may be determined according to the actual situation of the wind farm without specific limitations.

[0058] According to an embodiment of the present invention, the friction wheel motor assemblies 30 may be evenly distributed circumferentially along the support ring 10 and the drive ring 20.

[0059] According to an embodiment of the present invention, in the circumferential direction of the support ring 10 and the drive ring 20, the interval between the plurality of friction wheel motor assemblies 30 is not specifically limited and may be determined by the number of friction wheel motor assemblies 30.

[0060] According to an embodiment of the present invention, as Figure 1 shown, both the support ring 10 and the drive ring 20 may be annular, and the support ring 10 and the drive ring 20 may be coaxially arranged.

[0061] Optionally, as Figure 1 and Figure 2 shown, the drive ring 20 may be arranged radially inside the support ring 10. That is to say, the diameter of the support ring 10 may be larger than the diameter of the drive ring 20, and the drive ring 20 is arranged in the inner space of the support ring 10.

[0062] However, the present invention is not limited thereto. As an example, the drive ring 20 may be disposed radially outside the support ring 10. That is to say, the diameter of the drive ring 20 may be greater than the diameter of the support ring 10, and the support ring 10 is disposed in the inner space of the drive ring 20.

[0063] According to an embodiment of the present invention, the support ring 10 and / or the drive ring 20 may be an integral annular assembly. However, the present invention is not limited thereto. In order to reduce the manufacturing cost and facilitate the transportation and assembly of the system components, the support ring 10 and / or the drive ring 20 may be assembled from at least one section of annular assemblies.

[0064] According to an embodiment of the present invention, as Figure 4 shown, the friction wheel motor assembly 30 may include a motor 31 and a friction wheel 32.

[0065] As Figure 5 shown, the motor 31 may include a motor housing 31a, a stator (not shown) and a rotor (not shown) accommodated in the motor housing 31a, and a motor shaft 31b extending from the motor housing 31a. According to an embodiment of the present invention, the specific structures of the stator and rotor of the motor 31 are not limited.

[0066] The motor shaft 31b may be connected to the rotor of the motor 31. According to an embodiment of the present invention, as Figure 2 shown, the motor shaft 31b may be parallel to the axial directions of the support ring 10 and the drive ring 20.

[0067] According to an embodiment of the present invention, as Figure 4 and Figure 5 shown, the motor shaft 31b may extend from both sides of the motor 31, and at least one friction wheel 32 is mounted on each motor shaft 31b. Although Figure 4 shows that two friction wheels 32 are mounted on each motor shaft 31b, only one friction wheel 32 may be mounted on each motor shaft 31b, or three or more friction wheels 32 may be mounted.

[0068] In addition, as an example, the motor shaft 31b may extend only from one side of the motor 31, and at least one friction wheel 32 is mounted on each motor shaft 31b.

[0069] According to an embodiment of the present invention, the structures of the respective friction wheel motor assemblies 30 (for example, the number of the motor shafts 31b and the friction wheels 32) may be the same or different, without specific limitation. Preferably, the structures of the respective friction wheel motor assemblies 30 may be the same.

[0070] According to an embodiment of the present invention, as Figure 2 and Figure 7As shown, the drive ring 20 may include two raceways 21, and the two raceways 21 may be in contact with the friction wheels 32 on both sides of the motor 31 respectively. The friction wheels 32 may be any rolling elements capable of rolling on the raceways 21. Optionally, the friction wheels 32 may be rubber pneumatic tires or solid tires. Optionally, the friction wheels 32 may be made of at least one of, for example, metal materials, non-metal materials, and composite materials.

[0071] According to an embodiment of the present invention, the drive ring 20 may further include an isolation groove 22 disposed between the two raceways 21 and corresponding to the motor 31. The isolation groove 22 is recessed relative to the two raceways 21 to be spaced apart from the motor 31, so as to prevent the drive ring 20 from rubbing against the motor 31.

[0072] According to an embodiment of the present invention, driven by the drive ring 20, the friction wheels 32 are rotated by the frictional force of the drive ring 20, thereby driving the motor 31 to generate electricity.

[0073] Therefore, it is necessary to ensure that there is no slippage at the contact between the friction wheels 32 and the raceways 21 during transmission (i.e., pure rolling). According to an embodiment of the present invention, the friction drive system 100 may further include an automatic loading device, and the automatic loading device makes the normal pressure received by the friction wheels 32 increase as the frictional force increases. By providing the automatic loading device, it can be ensured that there is a sufficiently large frictional force at the contact between the friction wheels 32 and the raceways 21, so that there is no large sliding displacement between the friction wheels 32 and the raceways 21.

[0074] According to an embodiment of the present invention, an automatic loading device may be provided on each friction wheel motor assembly 30.

[0075] As an example, the automatic loading device may include a swing arm mechanism 40. As Figure 2 、 Figure 4 and Figure 5 shown, a swing arm mechanism 40 may be provided on each friction wheel motor assembly 30. The swing arm mechanism 40 may connect the friction wheel motor assembly 30 and the support ring 10 to each other. One end of the swing arm mechanism 40 is fixed to the friction wheel motor assembly 30, and the other end of the swing arm mechanism 40 is rotatable relative to the support ring 10. Therefore, driven by the drive ring 20, the friction wheel motor assembly 30 can swing relative to the support ring 10 together with the swing arm mechanism 40.

[0076] As an example, as Figure 5 shown, the swing arm mechanism 40 may include two swing arms 41 mounted on the motor 31, and the two swing arms 41 are parallel to each other. Each of the two swing arms 41 may be mounted on the motor housing 31a of the motor 31. Optionally, the two swing arms 41 may be perpendicular to the motor housing 31a of the motor 31.

[0077] As an example, a positioning pin hole 42 may be formed on each swing arm 41. Correspondingly, as Figure 6As shown, a set of pin holes 11 are circumferentially formed on the support ring 10. A connecting member (e.g., a positioning pin) 12 can pass through the positioning pin hole 42 and the pin hole 11 to rotatably connect the swing arm 41 to the support ring 10.

[0078] Under the driving force provided by the driving ring 20, the swing arm 41 and the friction wheel motor assembly 30 can swing relative to the support ring 10. The distance between the swing center line of the swing arm mechanism 40 (i.e., the center line of the positioning pin hole 42) and the center line of the motor shaft 31b is the effective length L of the swing arm.

[0079] Hereinafter, with reference to Figure 8 and Figure 9 describe the working principle diagram of the friction drive system according to an embodiment of the present invention.

[0080] Figure 8 is the working principle diagram of the friction drive system according to an embodiment of the present invention. For the sake of clear illustration, Figure 8 only one friction wheel motor assembly 30 is shown in

[0081] As Figure 8 shown, to ensure that there is no large sliding displacement between the friction wheel 32 and the raceway 21, the friction drive system 100 satisfies the friction self-locking condition of Equation 1 or a friction self-locking condition equivalent to Equation 1:

[0082]

[0083] where α is the angle between the connecting line OA from the center A of the friction wheel 32 and the motor shaft 31b to the driving center O of the driving ring 20 and the vertical line OC of the driving center O, β is the angle between the connecting line AB (the effective length L of the swing arm) from the center A to the swing center B of the swing arm mechanism 40 and the connecting line OA, mg is the component of the total weight of the friction wheel motor assembly 30 in the direction of the vertical line OC (in the case where the friction drive system 100 is placed as Figure 1 shown, the direction of the vertical line OC is the direction of gravity), Q is the total normal contact pressure between the friction wheel 32 and the driving ring 20, and μ is the contact friction coefficient between the friction wheel 32 and the driving ring 20.

[0084] According to an embodiment of the present invention, the friction self-locking condition equivalent to Equation 1 includes the following Equation 2:

[0085]

[0086] where F f is the tangential frictional force between the friction wheel 32 and the driving ring 20.

[0087] When the friction drive system 100 according to the present invention operates, the drive ring 20 can rotate to provide a driving force. For example, when the friction drive system 100 is applied to a wind turbine generator set, the drive ring 20 can be driven by the impeller main shaft of the wind turbine generator set to rotate. For example, the drive ring 20 can rotate in the clockwise direction (as Figure 1 , Figure 2 and Figure 8 shown).

[0088] When the drive ring 20 rotates, the drive ring 20 can drag the friction wheel 32 to rotate counterclockwise through the frictional force F f = μQ. At the same time, this frictional force F f also exerts a moment on the swing arm 41 to swing counterclockwise, wedging the friction wheel 32 between the drive ring 20 and the support ring 10. Since the sum of the lengths of the connecting line OA and the connecting line AB is greater than the distance from the swing center B to the drive center O, the resultant effect of this moment makes the total normal contact pressure Q between the friction wheel 32 and the raceway 21 increase as F f increases, achieving automatic loading.

[0089] According to an embodiment of the present invention, in order to make each friction wheel motor assembly 30 satisfy Equation 1 or Equation 2, the effective length L of the swing arm of the swing arm mechanism 40 (the connecting line AB in Figure 8 ) can be adjusted according to the position of the friction wheel motor assembly 30 (angular coordinates, the included angle α of the friction wheel motor assembly 30), and / or the distance OB from the swing center B of the swing arm mechanism 40 to the drive center O can be adjusted.

[0090] A necessary condition for achieving automatic loading is to maintain an initial contact between the friction wheel 32 and the raceway 21 of the drive ring 20. When α + β is less than or equal to 180 degrees, the friction wheel 32 and the raceway 21 naturally ensure initial contact under the action of the self-weight of the friction wheel motor assembly.

[0091] However, when α + β is greater than 180 degrees, the friction wheel 32 and the raceway 21 need to rely on an external force to maintain the initial contact. According to an embodiment of the present invention, the automatic loading device may further include a compression spring 50 installed on the support ring 10. The compression spring 50 can be a compressed spring. Although not shown, one end of the compression spring 50 can be installed on the support ring 10, and the other end of the compression spring 50 can be pressed against the side surface of each swing arm 41 of the swing arm mechanism 40 to apply an elastic force to the swing arm mechanism 40.

[0092] Figure 9 is a working principle diagram of a friction drive system according to another embodiment of the present invention. As Figure 9As shown, the compression spring 50 can act on the swing arm 41 of the swing arm mechanism 40 to provide an elastic force to the swing arm mechanism 40, so that the friction wheel 32 is pressed against the driving ring 20, thereby keeping an initial contact between the friction wheel 32 and the raceway 21 of the driving ring 20.

[0093] In the present invention Figure 1 and Figure 2 shows a situation where the friction drive system 100 is placed such that the axes of the support ring 10 and the drive ring 20 are parallel to the horizontal plane. However, the present invention is not limited thereto. As another example, the friction drive system 100 is placed such that the axes of the support ring 10 and the drive ring 20 are perpendicular to the horizontal plane, that is, Figure 1 the friction drive system 100 in

[0094] is rotated clockwise by 90 degrees.

[0095] tanβ≤μ (3)

[0096] where β is the angle between the connecting line AB and the connecting line OA, and μ is the contact friction coefficient between the friction wheel 32 and the drive ring 20.

[0097] Formula (3) can be regarded as a special case of formula (1) or formula (2). When the axes of the support ring 10 and the drive ring 20 are perpendicular to the horizontal plane, Figure 8 the direction of OC in

[0098] is the horizontal direction, so the component of the total weight of the friction wheel motor assembly 30 in the OC direction is 0, and thus formulas (1) and (2) degenerate into formula (3). In this case, the friction self-locking condition is independent of the position (angular coordinates, the included angle α of the friction wheel motor assembly 30) of the friction wheel motor assembly 30.

[0099] According to another embodiment of the present invention, a wind turbine generator set including the above-mentioned friction drive system 100 is further provided.

[0100] According to an embodiment of the present invention, the friction drive system 100 can be placed such that the axes of the support ring 10 and the drive ring 20 are parallel or perpendicular to the horizontal plane. The support ring 10 can be connected to a fixed component in the wind turbine generator set, and the drive ring 20 can be driven by the impeller main shaft of the wind turbine generator set.

[0101] As an example, the friction drive system 100 is placed such that the axes of the support ring 10 and the drive ring 20 are parallel to the horizontal plane (that is, as in Figure 1placed vertically as shown in [FIGURE]. At this time, the support ring 10 can be connected to the base or fixed shaft of the wind turbine generator to provide support, and the drive ring 20 can be installed on the impeller main shaft of the wind turbine generator.

[0102] As another example, the friction drive system 100 is placed such that the axes of the support ring 10 and the drive ring 20 are perpendicular to the horizontal plane (i.e., placed horizontally). At this time, the support ring 10 can be connected to the tower or flange of the wind turbine generator to provide support. In this case, the impeller main shaft can transmit the driving force to the drive ring 20 through, for example, a steering gear.

[0103] When the friction drive system 100 is operating, the drive ring 20 can be driven by the impeller main shaft to rotate. The drive ring 20 drags the friction wheel 32 to rotate through friction. Since the motor shaft 31b is fixedly connected to the friction wheel 32, when the friction wheel 32 rotates, the motor shaft 31b also rotates, thereby driving the motor 31 to generate electricity.

[0104] According to the friction drive system of the present invention, by using friction wheels for power transmission, compared with gear transmission, the design, manufacturing, and operation and maintenance costs can be significantly reduced.

[0105] In addition, according to the friction drive system of the present invention, compared with the direct drive system in the prior art, the load on the main shaft bearing is small and it is not easy to fail.

[0106] Furthermore, according to the friction drive system of the present invention, multiple distributed generator sets can be used to replace a large-power central generator set for power generation, modular design and assembly can be realized, and the number of actually operating generator sets can be determined in real time according to the wind energy resources to improve the utilization rate of wind energy.

[0107] Although the exemplary embodiments of the present invention have been specifically described with reference to their exemplary embodiments, those skilled in the art should understand that various changes in form and details can be made without departing from the spirit and scope of the present invention defined by the claims.

Claims

1. A friction drive system, characterized in that, the friction drive system (100) comprises: a support ring (10); a drive ring (20) that provides a driving force, is disposed radially inside the support ring (10), and is coaxially arranged with the support ring (10); a plurality of friction wheel motor assemblies (30) that are circumferentially distributed along the support ring (10) and the drive ring (20), and are assembled radially between the support ring (10) and the drive ring (20), each friction wheel motor assembly (30) includes a motor (31) and a friction wheel (32), and the friction wheel (32) is fixed to a motor shaft (31b) of the motor (31), wherein, the friction wheel (32) is in frictional contact with the drive ring (20), and under the drive of the drive ring (20), the friction wheel (32) rotates due to the frictional force of the drive ring (20), and further the motor shaft (31b) rotates to drive the motor (31) to generate electricity, and wherein, the friction drive system includes an automatic loading device, the automatic loading device makes the normal pressure received by the friction wheel (32) increase with the increase of the frictional force, the automatic loading device includes a swing arm mechanism (40), one end of the swing arm mechanism (40) is fixed to the friction wheel motor assembly (30), and the other end of the swing arm mechanism (40) is rotatably connected to the support ring (10).

2. The friction drive system according to claim 1, characterized in that, the motor shaft (31b) is parallel to the axial directions of the support ring (10) and the drive ring (20).

3. The friction drive system according to claim 1, characterized in that, each friction wheel motor assembly (30) is provided with the automatic loading device.

4. The friction drive system according to claim 1, characterized in that, the automatic loading device further includes a compression spring (50) installed on the support ring (10), the compression spring (50) acts on the swing arm mechanism (40) such that the friction wheel (32) presses against the drive ring (20).

5. The friction drive system according to claim 1 or 4, characterized in that, the friction drive system (100) satisfies Equation 1 or a friction self-locking condition equivalent to Equation 1: （1） Wherein, is the included angle between the connecting line OA from the center A of the friction wheel (32) and the motor shaft (31b) to the driving center O of the driving ring (20) and the vertical line OC at the driving center O, is the included angle between the connecting line AB from the center A to the swing center B of the swing arm mechanism (40) and the connecting line OA, mg is the component of the total weight of the friction wheel motor assembly (30) in the direction of the vertical line OC, Q is the total normal contact pressure between the friction wheel (32) and the driving ring (20), is the contact friction coefficient between the friction wheel (32) and the driving ring (20).

6. The friction drive system according to claim 5, characterized in that, the friction self-locking condition equivalent to Equation 1 includes Equation 2: （2） Among them, F f is the tangential frictional force between the friction wheel (32) and the drive ring (20).

7. The friction drive system according to claim 6, characterized in that, According to the included angle of the friction wheel motor assembly (30) , adjust at least one of the effective length L of the swing arm of the swing arm mechanism (40) and the distance OB from the swing center B of the swing arm mechanism (40) to the drive center O, so that each friction wheel motor assembly (30) satisfies Formula 1 or Formula 2. The effective length L of the swing arm is the distance between the swing center line of the swing arm mechanism (40) and the center line of the motor shaft (31b).

8. The friction drive system according to claim 1 or 4, characterized in that, the friction drive system (100) is placed such that the axes of the support ring (10) and the drive ring (20) are perpendicular to the horizontal plane, and the friction drive system (100) satisfies the friction self-locking condition of Equation 3: （3） Wherein, is the included angle between the line AB connecting the center A of the motor shaft (31b) to the swing center B of the swing arm mechanism (40) and the line OA connecting the center A of the motor shaft (31b) to the driving center O of the driving ring (20); is the contact friction coefficient between the friction wheel (32) and the driving ring (20).

9. The friction drive system according to claim 1, characterized in that, The swing arm mechanism (40) includes two swing arms (41) mounted on the motor (31). The two swing arms (41) are parallel to each other. The swing arms (41) are connected to the support ring (10) through a connecting member (12) and can swing relative to the support ring (10).

10. The friction drive system according to claim 1, wherein, the drive ring (20) and / or the support ring (10) is assembled by at least one section of annular components.

11. The friction drive system according to claim 1, wherein, the motor shaft (31b) extends from both sides of the motor (31). At least one of the friction wheels (32) is mounted on each motor shaft (31b). The drive ring (20) includes two raceways (21), and the two raceways (21) are respectively in contact with the friction wheels (32) on both sides of the motor (31).

12. The friction drive system according to claim 11, wherein, the drive ring (20) includes an isolation groove (22) provided between the two raceways (21) and corresponding to the motor (31). The isolation groove (22) is concave relative to the two raceways (21) to be spaced apart from the motor (31).

13. A wind power generating set, wherein, the wind power generating set includes the friction drive system (100) according to any one of claims 1 to 12.

14. The wind power generating set according to claim 13, wherein, the friction drive system (100) is placed such that the axes of the support ring (10) and the drive ring (20) are parallel or perpendicular to the horizontal plane. The support ring (10) is connected to a fixed component in the wind power generating set, and the drive ring (20) is driven by the impeller main shaft of the wind power generating set.

15. The wind power generating set according to claim 14, wherein, the friction drive system (100) is placed such that the axes of the support ring (10) and the drive ring (20) are parallel to the horizontal plane. The support ring (10) is connected to the base or fixed shaft of the wind power generating set, and the drive ring (20) is mounted on the impeller main shaft.

16. The wind power generating set according to claim 14, wherein, the friction drive system (100) is placed such that the axes of the support ring (10) and the drive ring (20) are perpendicular to the horizontal plane. The support ring (10) is connected to the tower or flange of the wind power generating set, and the impeller main shaft transmits the driving force to the drive ring (20) through a steering gear.

Images