Kaplan turbine

Abstract

The invention relates to a Kaplan-type turbine (10) comprising a stator portion (11) and a rotor portion (12), the stator portion (11) comprising a conduit (13) adapted to convey a water flow towards an impeller (14) having an axis of rotation (X1), and a stator (15) of a generator, while the rotor portion (12) comprises: - an impeller (14) further comprising: - an ogive (16) with at least three blades (17) having a variable angular arrangement with respect to an inclined axis (X2) substantially perpendicular to the axis of rotation (X1); - a rotating shaft (18) supporting the impeller (14); - adjustment means (19) for adjusting the arrangement of the blades (17) defined inside the ogive (16) and the rotating shaft (18); - a generator rotor (20) fixed to the rotating shaft (18). The adjusting means (19) for adjusting the arrangement of the blades (17) comprise, for each blade (17), - a load-bearing disc (21) on which one of the blades (17) extends, the load-bearing disc (21) being constrained to rotate on the ogive (16) about the tilt axis (X2), - a lever (23) fixed to the load-bearing disc (21) and extending radially to the tilt axis (X2), inside the ogive (16), - a steering rod (24) pivoting relative to the lever (23) and relative to the drive slider (25).

Description

Technical Field

[0001] The present invention relates to a Kaplan turbine.

Background Art

[0002] Recently, in all fields, there has been an increasing need to pursue production and manufacturing choices that pay meticulous attention to ecology, and as a result, the greatest concern for the environment has been growing.

[0003] In a Kaplan turbine, as the hydraulic operating state changes, it is desirable to be able to change the blade tilt angle in order to operate with better performance.

[0004] The blade motion structure generally includes a "connecting rod - crank" type of motion with a spider that can translate along the rotation axis of the turbine for each blade, and all the connecting rods of the blade are pinned to the spider.

[0005] The translational motion of the spider along the rotation axis of the turbine generates the angular motion of the blade itself by each "connecting rod - crank" motion.

[0006] Such a mechanism ensures the synchronization of rotation between the blades.

[0007] In the current solution, the spider is moved by a hydraulic servo motor in the machine, and oil is supplied through a rotary joint, and the entire system rotates by the turbine itself.

[0008] Therefore, although these Kaplan turbines are widely recognized, there is this drawback related to the risk of environmental pollution in the case of oil leakage from the hydraulic servo or rotary joint.

[0009] In fact, the mineral oil used for driving the reciprocating movable part and for its lubrication can be quite polluting, and it is necessary to avoid the risk of contamination leaking from the turbine into the water collecting tank through which the water flowing through the turbine itself.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] The problem of the present invention is to develop a Kaplan turbine that can overcome the above-mentioned drawbacks and limitations of the prior art.

[0011] Specifically, the object of the present invention is to develop a Kaplan turbine that eliminates the risk of environmental pollution caused by oil leakage from the turbine itself.

[0012] Another object of the present invention is to develop a Kaplan turbine that has strength and efficiency not inferior to those of similar Kaplan turbines of known types.

MEANS FOR SOLVING THE PROBLEMS

[0013] The problem and the above-mentioned object are achieved by the Kaplan turbine according to claim 1.

[0014] Further characteristics of the Kaplan turbine according to claim 1 are explained in the dependent claims.

[0015] The problem and the above-mentioned object, together with the advantages mentioned below, are shown by the description of the embodiments of the invention given by way of non-limiting examples with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

DETAILED DESCRIPTION OF THE INVENTION

[0017] Referring to the foregoing figures, a Kaplan turbine according to the present invention is generally designated by the number 10.

[0018] This turbine 10 includes a stator portion 11 and a rotor portion 12.

[0019] The stator portion 11 is, as schematically shown by the dotted line in FIG. 1, - a conduit 13 configured to convey water flow towards an impeller 14 having a rotation axis X1, which rotation axis X1 can be substantially vertical or can have another inclination angle, and the conduit 13, - a stator 15 of a generator.

[0020] The stator portion 12 includes - an impeller 14, and the impeller 14 further includes - an ogee 16 with at least three blades, for example, but not limited to, three blades 17, each of the blades 17 being of a type having a variable angle arrangement with respect to an inclination axis X2, and the inclination axis X2 clearly visible in FIG. 3 being substantially perpendicular to the rotation axis X1, the ogee 16, - a rotating shaft 18 supporting the impeller 14, - Adjusting means 19 for adjusting the arrangement of the blades 17 defined inside the hub 16 and the rotating shaft 18, - As schematically shown in FIG. 1, in the stator 15, a rotor 20 of a generator fixed to the rotating shaft 18.

[0021] Regarding the characteristics of the Kaplan turbine 10 according to the present invention, the adjusting means 19 for adjusting the arrangement of the blades 17, for each blade 17, - As clearly visible in FIG. 3, a load-bearing disk 21 on which the blade 17 extends, the load-bearing disk 21 being constrained to rotate on the hub 16 around the inclined axis X2, the load-bearing disk 21, - A lever 23 fixed to the load-bearing disk 21 and extending inside the hub 16, specifically, the lever 23 extends radially with respect to the inclined axis X2, the lever 23, - A control rod 24 pivoting at a first end 24a with respect to the lever 23 and at a second opposite end 24b with respect to the drive slider 25, There is the fact of comprising.

[0022] The means 19 for adjusting the arrangement of the blade 17 is also inside the hub 16, - The drive slider 25 already described above, around which the second end 24b of the control rod 24 pivots, - An axial translation system 26 for the drive slider 25, of the type of a nut 27 and a worm screw 28, the nut 27 being fixed to the drive slider 25, the worm screw 28 being fixed coaxially with a drive shaft 29 positioned to operate inside the rotating shaft 18, the axial translation system 26.

[0023] The means 19 for adjusting the arrangement of the blade 17 also comprises a pneumatic rotary actuator 30 for the drive shaft 29.

[0024] The pneumatic rotary actuator 30, - An air motor 31 mounted so as to ride on a rotating shaft 18 and configured to rotate a drive shaft 29 with respect to the rotating shaft 18, - An air rotary joint 32 including an external stator body 33 fixed to a fixed support structure and clearly visible in FIG. 9, and an internal rotating body 34 configured to reciprocate and transmit compressed air to the air motor 31.

[0025] The inside of the rotating shaft 18 is hollow.

[0026] The drive shaft 29 is coaxial with the rotating shaft 18.

[0027] The drive shaft 29 passes through the rotating shaft 18 that is coaxial therewith.

[0028] The worm screw 28 is, for example, but not limited to, a recirculating ball screw.

[0029] The ogive 16 includes an internal hollow spherical body 37 that supports a central collar 38 coaxial with the rotating shaft 18.

[0030] The ogive 16 includes a bottom 39 fixed to the spherical body 37.

[0031] The ogive 16 is firmly connected to the rotating shaft 18 by a hub 40.

[0032] The drive shaft 29 is connected to the air motor 31 at a first end and to the worm screw 28 at an opposite second end.

[0033] The drive shaft 29 is connected to the worm screw 28 using a joint 42.

[0034] The locking of the joint 42 to the worm screw 28 is preferably carried out with a "superbolt" type clamp and tension system.

[0035] In the joint 42, there is also a support with a bearing 43 for the worm screw 28.

[0036] The worm screw 28 passes through the central collar 38.

[0037] The worm screw 28 passes through the central collar 38 without contacting the central collar 38.

[0038] The worm screw 28 is rotatably constrained to the bottom 39 by a friction reducing component, such as a bushing 45.

[0039] The central collar 38 defines, with the spherical body 37, a gap in which the lever 23 is received together with each of the control rods 24.

[0040] As a non - limiting example of the present invention, in the embodiments described herein, each of the levers 23 is supported by a pin 22 fixed to the disk 21. As a further example, each of the pins 22 forms a unitary body with each of the disks 21.

[0041] The central collar 38 extends like a cantilever inside the spherical body 37.

[0042] A movement space is defined between the free end 38a of the central collar 38 and the bottom 39 for the slider 25 and the nut 27 fixed to the slider 25.

[0043] Each of the disks 21 rotates in a corresponding seat defined by the spherical body 37 by the interposition of a bushing 44, or by the interposition of another similar and technically equivalent friction reducing component.

[0044] As described above and as can be seen in FIG. 3, each of the disks 21 has a radial pin 22 extending from the disk 21 itself, and the radial pin 22 extends until it comes to rest in a counter - type hole 51 defined by the central collar 38.

[0045] The radial pin 22 supports the lever 23.

[0046] The lever 23 includes a fixed base 23a for fixing to the disk 21 and a head 23b pivotally attached to the control rod 24.

[0047] The control rod 24 includes, for example, two symmetrical bars that define forks pivotally attached to one side of the lever 23 and to the opposite side of the slider 25.

[0048] For example, the slider 25 consists of a disk-shaped body.

[0049] As can be seen in FIGS. 6 and 7, the slider 25 includes small holes 55 configured to be pivotally attached to corresponding ends 24b of the control rod 24, respectively.

[0050] The nut 27 is of the recirculating ball type.

[0051] Between the arrangement of the upper end of the stroke, illustrated as well as can be seen in FIGS. 3, 4, and 7, and the arrangement of the lower end of the stroke, illustrated in FIG. 6, the slider 25 translates freely.

[0052] Accordingly, the upper end 46 of the stroke element that defines the arrangement of the upper end of the stroke and the lower end 47 of the stroke element that defines the arrangement of the lower end of the stroke are defined inside the ogive 16.

[0053] Preferably, the upper end 46 of the stroke element and the lower end 47 of the stroke element are configured and positioned to touch the slider 25.

[0054] In a non-limiting embodiment of the present invention, the upper end 46 of the stroke element consists of an annular body fixed to the slider 25 and is configured to touch the lower edge of the free end 38a of the central collar 38.

[0055] Similarly, by way of example, the lower end 47 of the stroke element consists of a disk with one or more stationary protrusions 47a configured to touch the slider 25 and not touch the nut 27.

[0056] The lower end 47 of the stroke element is fixed to the lower end of the worm screw 28.

[0057] Specifically, and by way of example, the lower end 47 of the stroke element is fixed to the worm screw 28 using a "superbolt" type clamp and a tensioning system.

[0058] The pneumatic rotary actuator 30 also includes a tubular support 60 that is integral with and coaxial with the rotary shaft 18.

[0059] The air motor 31 is fixed inside this tubular support 60.

[0060] As can be clearly seen in FIG. 9, the inner rotating body 34 of the pneumatic rotary joint 32 is fixed to the cover 61 of the tubular support 60 so as to rotate coaxially with the rotary shaft 18.

[0061] The inner rotating body 34 is fixed to the outside of the tubular support 60.

[0062] The cover 61 has two through channels 62 and 63 for compressed air, namely, a first channel 62 and a second channel 63.

[0063] These first channel 62 and second channel 63 are each connected to an inlet conduit 62a and an outlet conduit 63a defined by the inner rotating body 34 of the pneumatic rotary joint 32.

[0064] These first channel 62 and second channel 63 are connected to a corresponding inlet joint 64 and a corresponding outlet joint 65 of the air motor 31.

[0065] The first channel 62 and the second channel 63 operate alternately, with one acting as the outer channel and the other as the return channel, and vice versa.

[0066] The external stator body 33 of the pneumatic rotary joint 32 is supported by a fixed structural element, i.e., a stationary structural element, not shown for simplicity.

[0067] The pneumatic rotary joint 32 is further connected to an air compressor, which is intended to be of a clearly known type.

[0068] This air compressor is configured to circulate air through the pneumatic rotary joint 32, for example, at a pressure of 6 bar.

[0069] The turbine (10) also includes detection means 70 for detecting the angular position of the blade 17.

[0070] In the embodiments described in this specification of the present invention, which are exemplary and non-limiting of the present invention itself, the detection means 70 includes - a moving body 80, - displacement means 81 configured to displace the moving body 80 in proportion to the rotation angle of the blade 17, - a sensor 82 configured to detect the displacement of the moving body 80. and is provided with.

[0071] For example, the moving body 80 includes an annular body 80a installed so as to surround the tubular support 60.

[0072] The annular body 80a is constrained by one or more rotatable screw-type stems 83, and the rotation of the stems 83 displaces the same annular body 80a in a first direction or a second opposite direction in the direction of the rotation axis X1.

[0073] Each of the rotatable screw-type stems 83 is installed to rotate with a screw-type bushing 84 fixed to the annular body 80a.

[0074] Each of the screw-type stems 83 is installed to rotate such that its main axis is parallel to the rotation axis X1.

[0075] Each of the screw-type stems 83 has a drive toothed wheel 85.

[0076] Each of the drive toothed wheels 85 is integrated with the drive shaft 29, that is, it meshes with a drive toothed wheel 86 fixed to the drive shaft 29.

[0077] The screw-type stem 83 is supported by a support structure 87 fixed to the rotating shaft 18.

[0078] Specifically, in the embodiment of the present invention, the support structure 87 includes a base disk 88 fixed to the upper end of the rotating shaft 18 and an annular cover 89 by which the screw-type stem 83 is rotatably constrained.

[0079] Each of the screw-type stems 83 is rotatably constrained to the annular cover 89 by corresponding bushings 90 clearly visible in FIG. 8.

[0080] The tubular support 60 is fixed to the annular cover 89.

[0081] Also, the air motor 31 is fixed to the annular cover 89.

[0082] As clearly visible in FIG. 8, the rotating shaft 31a of the air motor 31 is fixed to the drive shaft 29 using a transmission sleeve 91.

[0083] The drive toothed wheel 86 is clearly coaxial and fixed to the transmission sleeve 91.

[0084] The sensor 82 is, for example, an infrared sensor.

[0085] This sensor 82 is fixed to the fixed structure portion 95 of the turbine 10 or the fixed structure portion 95 of the compartment that houses the turbine 10.

[0086] The sensor 82 faces the annular body 80a.

[0087] Specifically, the sensor 82 faces the annular body 80a in a direction substantially parallel to the rotation axis X1.

[0088] The rotation of the drive shaft 29 relative to the rotary shaft 18 causes the synchronous rotation of the screw stem 83. The rotation of the screw stem 83 further causes displacement in the direction of the rotation axis X1 of the annular body 80a in either a state of moving towards the sensor 82 or away from the sensor 82.

[0089] This displacement of the annular body 80a is detected by the sensor 82 and converted by the electronic control unit into the value of the inclination of the blade 17.

[0090] Therefore, the position of the annular body 80a relative to the sensor 82 is proportional to the inclination angle of the blade 17 with respect to a predetermined angular reference.

[0091] Therefore, the operation of the adjusting means 19 for adjusting the angular arrangement of the blade 17 is described below.

[0092] When it is desired to change the arrangement of the blade 17, the external compressor becomes active, causing a pressurized air flow to enter the air motor 31 through, for example, air 32 at 6 bar. Formula Rotating Joint The air motor 31 has a stator portion fixed to the tubular support 60 and further fixed to the rotary shaft 18 supporting the impeller 14, and a rotary shaft 31a fixed to the drive shaft 29.

[0093] Next, the air motor 31 induces the rotation of the drive shaft 29 in one or the opposite rotational direction.

[0094] The rotation of the drive shaft 29 causes the translation of the nut 27 and thus the translation of the slider 25 fixed to the nut 27, either in the downward direction, i.e., towards the bottom 39 of the bellows 16, or in the upward direction, i.e., in the opposite direction, depending on the rotational direction.

[0095]

[0096] ​ Furthermore, the translation of the slider 25 causes each of the rods 24 to act on the lever 23 of the blade 17.

[0097] For example, in FIG. 6, when the slider 25 descends, a downward traction on the lever 23 is generated through the rod 24, and as a result, rotation occurs in the first rotation direction of the disk 21 to which the blade 17 is fixed, for example, counterclockwise, as illustrated.

[0098] In FIG. 7, when the slider 25 ascends, an upward thrust on the lever 23 is generated through the rod 24, and as a result, rotation occurs in the second rotation direction of the disk 21 to which the blade 17 is fixed, for example, clockwise, as illustrated.

[0099] As described above, the translation of the slider 25 is performed between the arrangements at the two ends of the stroke, one upper end and one lower end, and each of the upper end and the lower end defines the respective angular limit positions of the blade 17, and the blade 17 cannot rotate beyond the angular limit positions with respect to its tilt axis X2.

[0100] The rotating shaft 18 is supported at its ends by at least two bearings 96a and 96b, and those bearings are further constrained by corresponding fixed radial supports 97 and 98.

[0101] In fact, it has been demonstrated that the present invention achieves the intended problems and objectives.

[0102] Specifically, by means for adjusting the angular arrangement of the blades that function without using either oil or other liquids using the present invention, a Kaplan turbine has been developed that makes it possible to eliminate the risk of environmental pollution caused by oil leakage from the turbine itself.

[0103] Furthermore, a Kaplan turbine has been developed using the present invention that has the same level of robustness and efficiency as a similar Kaplan turbine of a known type.

[0104] The invention thus conceived is capable of many modifications and variations, all of which are included within the scope of the same inventive concept. Further, all details can be replaced by other equivalent technical elements.

[0105] In fact, not only the components and materials used, but also the dimensions and attendant shapes can be any according to the requirements of the art and the state of the art, as long as they are compatible with the particular use.

[0106] If the characteristics and techniques referred to in any claim follow reference signs, such reference signs are intended to be attached only for the purpose of enhancing the understanding of the claim, and as a result, such reference signs do not limit the effect on the interpretation of each element identified by such reference signs, by way of example.

Claims

1. A Kaplan turbine (10) including a stator portion (11) and a rotor portion (12), wherein the stator portion (11) includes - a conduit (13) configured to convey water flow towards an impeller (14) having a rotation axis (X1), and - a stator (15) of a generator, and the rotor portion (12) includes - an impeller (14), and the impeller (14) further includes - an ogee (16) with at least three blades (17) having a variable angle arrangement with respect to an inclination axis (X2) substantially perpendicular to the rotation axis (X1), - a rotating shaft (18) supporting the impeller (14), - adjusting means (19) for adjusting the arrangement of the blades (17) defined inside the ogee (16) and the rotating shaft (18), and - a rotor (20) of the generator fixed to the rotating shaft (18) in the stator (15), the means (19) for adjusting the arrangement of the blades (17) includes, for each blade (17), - a load-bearing disk (21) where one of the blades (17) extends, and the load-bearing disk (21) is constrained to rotate on the ogee (16) around the inclination axis (X2), - a lever (23) fixed to the load-bearing disk (21) and extending inside the ogee (16), - a control rod (24) pivoting at a first end (24a) with respect to the lever (23) and at a second opposite end (24b) with respect to a drive slider (as), the means (19) for adjusting the arrangement of the blades (17) also includes, inside the ogee (16), - a drive slider (25) where the second end (24b) of the control rod (24) pivots, and - an axial translation system (26) for the drive slider (25), which is of the type of a nut (27) and a worm screw (28), the nut (27) being fixed to the drive slider (25), and the worm screw (28) being fixed coaxially with a drive shaft (29) positioned to operate inside the rotating shaft (18), The Kaplan turbine (10) is characterized in that the means (19) for adjusting the arrangement of the blade (17) further comprises a pneumatic rotary actuator (30) for the drive shaft (29).

2. The pneumatic rotary actuator (30) comprises: - a pneumatic motor (31) mounted to ride on the rotary shaft (18) and configured to rotate the drive shaft (29) relative to the rotary shaft (18); - a pneumatic rotary joint (32) including an external stator body (33) fixed to a fixed support structure and an internal rotating body (34) configured to reciprocate and transmit compressed air to the pneumatic motor (31). The turbine (10) according to claim 1 is characterized by this.

3. The interior of the rotary shaft (18) is hollow, and the drive shaft (29) is coaxial with the rotary shaft (18). The turbine (10) according to any one or more of claims 1 to 2 is characterized by this.

4. The worm screw (28) is a recirculating ball screw. The turbine (10) according to claim 1 is characterized by this.

5. The hub (16) comprises an internal hollow spherical body (37) that supports a central collar (38) coaxial with the rotary shaft (18). The hub (16) includes a bottom portion (39) fixed to the spherical body (37). The turbine (10) according to claim 1 is characterized in that the hub (16) is firmly connected to the rotary shaft (18) using a hub (40).

6. The drive shaft (29) is connected to the pneumatic motor (31) at a first end and to the worm screw (28) at a second end on the opposite side. The drive shaft (29) is connected to the worm screw (28) using a joint (42). The turbine (10) according to claim 2 is characterized by this.

7. The worm screw (28) passes through the central collar (38) and is constrained to the bottom portion (39) by a friction reducing component, such as a bushing (45). The turbine (10) according to claim 5 is characterized by this.

8. The central collar (38) extends like a cantilever inside the spherical body (37), and a movement space for the slider (25) and the nut (27) fixed to the slider (25) is defined between the free end (38a) of the central collar (38) and the bottom (39). The slider (25) translates freely between the arrangement at the upper end of the stroke and the arrangement at the lower end of the stroke. Inside the ogive (16), an upper end (46) of a stroke element defining the arrangement at the upper end of the stroke and a lower end (47) of a stroke element defining the arrangement at the lower end of the stroke are defined. The turbine (10) according to claim 5 or 7, characterized in that.

9. The pneumatic rotary actuator (30) includes a tubular support (60) that is integral with and coaxial with the rotary shaft (18). The air motor (31) is fixed inside the tubular support (60). The inner rotating body (34) of the pneumatic rotary joint (32) is fixed to the cover (61) of the tubular support (60) so as to rotate coaxially with the rotary shaft (18). The turbine (10) according to claim 2, characterized in that.

10. The turbine (10) according to claim 9, characterized in that it comprises detection means (70) for detecting the angular position of the blade (17).

11. The detection means (70) is - a moving body (80), - displacement means (81) configured to displace the moving body (80) in proportion to the rotation angle of the blade (17), - a sensor (82) configured to detect the displacement of the moving body (80), The turbine (10) according to claim 10, characterized by comprising.

12. The moving body (80) includes an annular main body (80a) installed so as to surround the tubular support (60). The annular main body (80a) is constrained by one or more rotatable screw-type stems (83). Rotation of the rotatable screw-type stems (83) causes displacement of the same annular main body (80a) in a first direction or in a second opposite direction in the direction of the rotation axis (X1). Each of the rotatable screw-type stems (83) is installed to rotate on a screw-type bushing (84) fixed to the annular main body (80a). Each of the screw-type stems (83) is installed so that the spindle of the screw-type stem (83) rotates in a state parallel to the rotation axis (X1). Each of the screw-type stems (83) has a drive toothed wheel (85), and each of the drive toothed wheels (85) meshes with a drive toothed wheel (86) integrated with the drive shaft (29). The turbine (10) according to claim 11, characterized in that.

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