Water guide mechanism of axial flow water turbine

Abstract

The utility model discloses an axial flow water turbine water guide mechanism which comprises an upper ring seat (1) and a lower ring seat (2), a plurality of guide vanes (3) are arranged between the upper ring seat (1) and the lower ring seat (2), rotating shafts (4) are arranged in the middles of the upper ends and the lower ends of the guide vanes (3), driving rings (5) are connected to the upper ring seat (1) in a rotating mode, servomotors (6) are connected to the driving rings (5), and the servomotors (6) are connected to the driving rings (5). The upper ends of the rotating shafts (4) are connected with the driving ring (5) through a first connecting rod (7) and a second connecting rod (8), and a linkage mechanism connected with the lower ends of all the rotating shafts (4) is arranged at the bottom of the lower ring seat (2); the linkage mechanism comprises a plurality of adapter plates (9), the adapter plates (9) are fixed to the lower ends of the rotating shafts (4) respectively, third connecting rods (10) are arranged between the adjacent adapter plates (9), and the third connecting rods (10) are hinged to the adapter plates (9). The utility model has the advantage of low maintenance frequency.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of water guide mechanism of axial flow type water turbine. BACKGROUND

[0002] Axial flow type water turbine has volute, the diameter of volute gradually reduces from inlet end to outlet end, water flow surrounds and flows in volute, the inside of volute is equipped with water guide mechanism, in addition to annular flow in volute, water in volute also flows radially inward through water guide mechanism, then drives water wheel to rotate, and water wheel drives generator set to generate electricity.

[0003] The structure of the existing water guide mechanism includes an upper ring seat and a lower ring seat. A plurality of guide vanes are evenly distributed circumferentially between the upper and lower ring seats. The central portions of the upper and lower ends of the guide vanes are each provided with a rotating shaft. The rotating shafts on the upper and lower sides are respectively rotatably connected to the upper and lower ring seats. A driving ring is rotatably connected to the upper ring seat. A servomotor is provided on both sides of the driving ring. One end of the servomotor is hingedly connected to the driving ring, and the other end of the servomotor is hingedly connected to the installation position of the water turbine. The driving ring is connected to the rotating shafts at the upper ends of the guide vanes in sequence through first and second connecting rods. The servomotor is extended and retracted to push the driving ring to rotate. The driving ring drives the rotating shafts to rotate through the first and second connecting rods, thereby causing the guide vanes to rotate. By changing the rotation angle of the guide vanes, the water inflow angle and flow rate of the water flow are changed. When all the guide vanes are connected end to end to form a ring, the water flow is cut off.

[0004] In the practice process, it is found that the most common problems of the existing water guide mechanism include the following:

[0005] First, the guide vanes are subjected to a large water flow impact on the rotating shafts for a long time, the upper rotating shaft is a fixed end supported by the servomotor, and the lower rotating shaft is a free end without external support, so that the upper end of the guide vane is also a relatively fixed end, and the lower end of the guide vane is a relatively free end. Under the impact of the water flow, the guide vanes twist around the axis of the rotating shaft as the center, forming a certain helix angle. Due to the differences in the water flow impact conditions between the guide vanes, the twisting degrees of the guide vanes are inconsistent, causing the water flow passages between the guide vanes to become inconsistent in size, disrupting the dynamic balance state designed with care, and increasing the failure rate due to vibration. In addition, in the closed state of the water guide mechanism, the adjacent guide vanes no longer fit tightly, and the water flow cutoff effect is poor.

[0006] Second, the water flow generates a large number of bubbles during rapid flow, which easily cause the rotating shafts to be subjected to cavitation erosion at the root portions of the rotating shafts, thereby reducing the strength of the rotating shafts and increasing the maintenance frequency of the water guide mechanism.

[0007] Third, the opening angle of the guide vane is determined by the extension length of the servomotor, after the guide vane is adjusted to the required angle, the self-locking mechanism in the servomotor is actuated to fix the extension length of the servomotor, the guide vane keeps the fixed angle, the impact force of the water flow on the guide vane is transmitted to the servomotor, so that the servomotor is in a long-term vibration working condition, and the servomotor is hydraulically driven, so that the wear speed of the internal sealing element is obviously increased in the vibration working condition, so that the servomotor is prone to oil leakage and other faults, and the maintenance frequency of the water guide mechanism is also increased. Content of the utility model

[0008] The utility model discloses a kind of axial flow water turbine water guide mechanisms, which has the advantages of lower maintenance frequency.

[0009] The technical scheme of the utility model discloses an axial flow water turbine water guide mechanism, which comprises an upper ring seat and a lower ring seat, a plurality of guide vanes are arranged between the upper ring seat and the lower ring seat, a rotating shaft is arranged at the middle part of the upper and lower ends of each guide vane, a driving ring is rotatably connected to the upper ring seat, a servomotor is connected to the driving ring, the upper end of the rotating shaft is connected to the driving ring through a first connecting rod and a second connecting rod, a linkage mechanism is arranged at the bottom of the lower ring seat, and all the rotating shafts located at the lower end of the guide vanes are connected to the linkage mechanism.

[0010] In the foregoing axial flow water turbine water guide mechanism, the linkage mechanism comprises a plurality of adapter plates, the lower end of each rotating shaft is fixed to one of the adapter plates, a third connecting rod is arranged between adjacent adapter plates, and the third connecting rod is hingedly connected to the adapter plates.

[0011] In the foregoing axial flow water turbine water guide mechanism, the root of the rotating shaft extends radially outward to form a flange edge, and the top surface of the flange edge is flush with the end surface of the guide vane.

[0012] In the foregoing axial flow water turbine water guide mechanism, an annular groove coaxial with the rotating shaft is arranged on the top surface of the flange edge.

[0013] In the foregoing axial flow water turbine water guide mechanism, an exhaust hole is arranged on the bottom surface of the annular groove, and the lower end of the exhaust hole is located on the bottom surface of the flange edge.

[0014] In the foregoing axial flow water turbine water guide mechanism, the flange edge is a square structure viewed from above, the bottom of the flange edge is a circular arc surface, the axis of the circular arc surface is perpendicular to the guide vane, there are two exhaust holes, the two exhaust holes are located on the two sides of the rotating shaft, respectively, and the lower end of each exhaust hole is located on the middle bisector of the circular arc surface.

[0015] In the foregoing axial flow water turbine guide vane mechanism, the inner edge of the upper ring seat extends upward to form an inner tube, the driving ring is sleeved on the inner tube, the upper end of the driving ring extends radially outward to form an upper flange, the upper flange is hinged to the servomotor, the lower end of the driving ring extends radially outward to form a lower flange, a first connecting rod and a second connecting rod are arranged between the lower flange and the rotating shaft at the upper end of the guide vane, one end of the first connecting rod is hinged to the lower flange, the other end of the first connecting rod is hinged to the second connecting rod, and the second connecting rod is fixed to the rotating shaft.

[0016] In the foregoing axial flow water turbine guide vane mechanism, the upper side of the upper flange is provided with a friction ring, the outer side of the friction ring is provided with a plurality of guide ears, the guide ears are provided with guide holes, the guide holes are provided with guide columns fixed to the upper ring seat, and the bottom of the upper flange is provided with a plurality of electromagnets.

[0017] Compared with the prior art, the axial flow water turbine guide vane mechanism has the following improvements on the basis of the prior art:

[0018] First, the bottom of the lower ring seat is provided with a linkage mechanism, the linkage mechanism connects the lower ends of the guide vanes through corresponding rotating shafts, so that the lower ends of all the guide vanes are linked, when the lower end of any guide vane is twisted, the lower ends of the remaining guide vanes are correspondingly twisted, after the guide vane mechanism is used for a long time, the twisting degrees of all the guide vanes tend to be consistent, the difference is reduced, the size of the water flow channel between the guide vanes is kept more consistent, the original dynamic balance state is less damaged, the vibration is reduced, the failure rate is reduced, and the maintenance frequency is reduced.

[0019] Second, a flange edge is arranged at the root of the rotating shaft, the path length of the bubbles passing through the gap between the guide vane and the ring seat to the root of the rotating shaft is prolonged, the cavitation of the rotating shaft is reduced, the strength of the rotating shaft is not prone to decrease, and the maintenance frequency is reduced.

[0020] Third, a friction ring is arranged above the driving ring, and electromagnets are arranged on the driving ring, when the guide vane does not need to be adjusted in angle, the magnetic force of the electromagnets is used to attract the friction ring, the driving ring is kept from moving by the connection between the friction ring and the driving ring, the impact force of the water flow on the guide vane is not easily transmitted to the servomotor, the vibration working condition of the servomotor is alleviated, the servomotor is not prone to failure, and the maintenance frequency of the guide vane mechanism is reduced.

[0021] In summary, the axial flow water turbine guide vane mechanism has the advantages of low maintenance frequency. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 This is a top-view perspective view of this utility model.

[0023] Figure 2 This is a bottom-view perspective view of this utility model.

[0024] Figure 3 This is a schematic diagram of the drive ring.

[0025] Figure 4 This is a top view of the guide vane.

[0026] Figure 5 This is a front view schematic diagram of the guide vane.

[0027] Figure 6 This is a schematic diagram of water flowing through the flange.

[0028] The markings in the attached diagram are as follows: 1-Upper ring seat, 2-Lower ring seat, 3-Guide vane, 4-Rotating shaft, 5-Drive ring, 6-Relay device, 7-First connecting rod, 8-Second connecting rod, 9-Adapter plate, 10-Third connecting rod, 11-Flange edge, 12-Annular groove, 13-Exhaust hole, 14-Arc surface, 15-Inner tube, 16-Upper flange, 17-Lower flange, 18-Friction ring, 19-Guide ear, 20-Guide post, 21-Electromagnet. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0030] Example: A guide vane mechanism for an axial-flow turbine, such as... Figure 1 As shown, it includes an upper ring seat 1 and a lower ring seat 2. Multiple guide vanes 3 are provided between the upper ring seat 1 and the lower ring seat 2. A small gap (0.1-0.2 mm) is formed between the guide vanes 3 and the upper ring seat 1, and between the guide vanes 3 and the lower ring seat 2. A rotating shaft 4 is provided at the middle of the upper and lower ends of each guide vane 3. The rotating shaft 4 at the upper end of the guide vane 3 passes through the upper ring seat 1, and the rotating shaft 4 at the lower end of the guide vane 3 passes through the lower ring seat 2. A drive ring 5 is rotatably connected to the upper ring seat 1. Relay devices 6 are connected to both sides of the drive ring 5. The upper end of the rotating shaft 4 is connected to the drive ring 5. Its features are as follows:

[0031] The bottom of the lower ring seat 2 is provided with a linkage mechanism. The linkage mechanism includes multiple triangular adapter plates 9, which are respectively fixed to the lower ends of multiple rotating shafts 4 located at the bottom of the corresponding guide vanes 3. A third connecting rod 10 is provided between adjacent adapter plates 9, and the third connecting rod 10 is hinged to the adapter plate 9.

[0032] The root of the rotating shaft 4 extends radially outward to form a flange edge 11, the top surface of which is flush with the end surface of the guide vane 3. The top surface of the flange edge 11 is provided with an annular groove 12 coaxial with the rotating shaft 4. The bottom surface of the annular groove 12 is provided with two exhaust holes 13, each located on the thick side of the guide vane 3. The flange edge 11 is square in plan view, and the bottom of the flange edge 11 is a circular arc surface 14 with an axis perpendicular to the guide vane 3. The lower ends of the exhaust holes 13 are located on the median bisector of the circular arc surface 14.

[0033] The inner edge of the upper ring seat 1 extends upward to form an inner tube 15, the drive ring 5 is sleeved on the inner tube 15, the upper end of the drive ring 5 extends radially outward to form an upper flange 16, the upper flange 16 is hinged to the servomotor 6, the lower end of the drive ring 5 extends radially outward to form a lower flange 17, and the first connecting rod 7 and the second connecting rod 8 are arranged between the lower flange 17 and the rotating shaft 4 at the upper end of the guide vane 3. One end of the first connecting rod 7 is hinged to the lower flange 17, the other end of the first connecting rod 7 is hinged to the second connecting rod 8, and the second connecting rod 8 is fixed to the rotating shaft 4.

[0034] The upper side of the upper flange 16 is provided with a friction ring 18, the outer side of the friction ring 18 is provided with a plurality of guide ears 19, the guide ears 19 are provided with guide holes, and guide columns 20 fixed to the upper ring seat 1 are arranged in the guide holes. The bottom of the upper flange 16 is provided with a plurality of electromagnets 21

[0035] Method for use: the upper ring seat 1 and the lower ring seat 2 are fixed on the installation position of the water guide mechanism, and the servomotor is hinged on the installation position of the water guide mechanism.

[0036] When one of the servomotors 6 is extended and the other servomotor 6 is retracted, the drive ring 5 rotates, the drive ring 5 drives the rotating shaft 4 to rotate through the first connecting rod 7 and the second connecting rod 8, the guide vane 3 rotates correspondingly, and the size and direction of the water flow are changed. Since all rotating shafts 4 are driven by the same drive ring 5, all guide vanes 3 maintain synchronous action.

[0037] When the servomotor 6 is working, the electromagnet 21 is in an open circuit state, and the drive ring 5 can rotate freely. When the guide vane 3 is adjusted to the appropriate angle and the servomotor 6 stops working, the electromagnet 21 is in a closed circuit state, the magnetic force of the electromagnet 21 attracts the friction ring 18, the friction ring 18 presses the drive ring 5 against the upper ring seat 1, the drive ring 5 cannot rotate, and the impact force of the water flow acting on the guide vane 3 cannot be transmitted to the servomotor, so the servomotor is not prone to failure, and the maintenance frequency is reduced.

[0038] Since the root of the rotating shaft 4 has a flange edge 11, the bubbles in the water flow are less likely to contact the root of the rotating shaft 4, the cavitation of the rotating shaft is reduced, the strength of the rotating shaft is less likely to decrease, and the maintenance frequency is reduced.

[0039] By setting the annular groove 12 on the flange edge, the bubbles are enriched in the annular groove 12, and by setting the exhaust hole on the bottom surface of the annular groove 12, the bubbles in the annular groove 12 are discharged through the exhaust hole. Here, the Bernoulli principle is utilized, and when the water flow passes from the bottom of the flange edge 11 at high speed, negative pressure is generated, and the water in the annular groove 12 carries the bubbles through the exhaust hole. As shown in Figure 6 Since the bottom of the flange edge 11 is a circular arc surface 14, the water flow passing through the guide vane is pressurized before reaching the exhaust hole, the flow rate is increased, and the suction to the exhaust hole 13 is increased.

Claims

1. A kind of axial flow water turbine guide mechanism, including upper ring seat (1) and lower ring seat (2), multiple guide vanes (3) are equipped between upper ring seat (1) and lower ring seat (2), the middle part of the upper and lower end of guide vane (3) is equipped with rotating shaft (4), driving ring (5) is rotatably connected on upper ring seat (1), driving ring (5) is connected with force amplifier (6) each, the upper end of rotating shaft (4) is connected driving ring (5) by first connecting rod (7) and second connecting rod (8), it is characterized by: The bottom of the lower ring seat (2) is provided with a linkage mechanism, and all the rotating shafts (4) located at the lower end of the guide vanes (3) are connected with the linkage mechanism. The linkage mechanism comprises a plurality of adapter plates (9), the plurality of adapter plates (9) are respectively fixed with the lower ends of the plurality of rotating shafts (4), and a third connecting rod (10) is arranged between adjacent adapter plates (9) and is hinged with the adapter plates (9).

2. The axial flow hydro turbine water directing mechanism according to claim 1, characterized in that: The root of the rotating shaft (4) extends radially outward to form a flange edge (11), and the top surface of the flange edge (11) is flush with the end surface of the guide vane (3).

3. The axial flow hydraulic turbine distributor according to claim 2, characterized in that: An annular groove (12) coaxial with the rotating shaft (4) is arranged on the top surface of the flange edge (11).

4. The axial flow hydraulic turbine distributor according to claim 3, characterized in that: An exhaust hole (13) is arranged on the bottom surface of the annular groove (12), and the lower end of the exhaust hole (13) is located on the bottom surface of the flange edge (11).

5. The axial flow hydro turbine distributor according to claim 4, characterized in that: The flange edge (11) is a square structure viewed upward, the bottom of the flange edge (11) is a circular arc surface (14), the axis of the circular arc surface (14) is perpendicular to the guide vane (3), and the exhaust hole (13) has two, the two exhaust holes (13) are respectively located on the two sides of the rotating shaft (4), and the lower ends of the exhaust holes (13) are located on the middle bisector surface of the circular arc surface (14).

6. The axial flow hydro turbine water directing mechanism of claim 1, wherein: The inner edge of the upper ring seat (1) extends upward to form an inner tube (15), the driving ring (5) is sleeved on the inner tube (15), the upper end of the driving ring (5) extends radially outward to form an upper flange (16), the servomotor (6) is hinged with the upper flange (16), the lower end of the driving ring (5) extends radially outward to form a lower flange (17), the first connecting rod (7) and the second connecting rod (8) are arranged between the lower flange (17) and the rotating shaft (4) at the upper end of the guide vane (3), one end of the first connecting rod (7) is hinged with the lower flange (17), the other end of the first connecting rod (7) is hinged with the second connecting rod (8), and the second connecting rod (8) is fixed with the rotating shaft (4).

7. The axial flow hydro turbine water directing mechanism of claim 6, wherein: The upper side of the upper flange (16) is provided with a friction ring (18), the outer side of the friction ring (18) is provided with a plurality of guide ears (19), the guide ears (19) are provided with guide holes, guide columns (20) fixed with the upper ring seat (1) are arranged in the guide holes, and the bottom of the upper flange (16) is provided with a plurality of electromagnets (21).

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