US20120097150A1

US20120097150A1 - Movement Mechanism and Solar Plant Using Said Mechanism

Info

Publication number: US20120097150A1
Application number: US13/381,029
Authority: US
Inventors: Luigi De Cillia; Giordano Durí; Gianfranco Zuliani
Original assignee: D D Srl
Current assignee: D D Srl
Priority date: 2009-06-25
Filing date: 2010-06-24
Publication date: 2012-04-26
Also published as: WO2010150085A1; ES2537439T3; EP2446199A1; IT1398116B1; IL217169A0; ITUD20090121A1; EP2446199B1

Abstract

Movement mechanism for at least an interception element assembled mobile on a support frame to assume an optimized interception condition. The movement mechanism is suitable to be assembled on the support frame and to be constrained to the interception element, in order to allow the movement thereof with respect to the support frame, and comprises a fixed body suitable to be assembled on the support frame, a rotating body assembled rotatable inside the fixed body around an axis of rotation and suitable to be constrained to the interception element, and a plurality of rolling members disposed rotating between relative sliding tracks made both on the fixed body and also on the rotating body. The mechanism movement comprises at least a compensation seating made on the fixed body and/or on the rotating body which extends with respect to said sliding tracks in a direction substantially parallel to the axis of rotation, to define a controlled play of axial displacement controlled by the rolling members.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention concerns a mechanism for moving one or more interception elements suitable at least to intercept a light wave, sound wave, radio wave or other type of wave. In particular the present invention is advantageously, but not exclusively, applied in a solar plant, for example of the concentration type, in which the interception elements are a plurality of reflection plates suitable to concentrate the sun's rays in suitable collectors, in order to exploit the solar energy. The reflection plates are assembled mobile on a frame, in order to assume an optimized exposure to the sun's rays at least according to the time of day, following, for example, the azimuthal angle of the sun.
The present invention also concerns a solar plant which uses the mechanism for moving the reflection plates.
2. Description of Related Art
Solar plants are known, in particular of the concentration type, in which a plurality of reflection plates or mirrors are suitably conformed, normally concave, in order to intercept and concentrate the sun's rays toward a common collector in which a saline or other solution flows, to accumulate energy.
It is known that the saline solution is then used to transform the accumulated energy into usable energy, for example electric, thermal or other.
Concentration solar plants are also known, in which the reflection plates are movable in order to be selectively oriented according to the azimuthal angle of the sun, following at least in part the daily movement thereof, and thus optimizing to the full the exploitation of the available solar energy.
Plants are also known in which the reflection plates are disposed in series on a number of rows and are assembled on a relative support frame, and as many as several dozen or at times hundreds of reflection plates are used.
The reflection plates in the same row are assembled on a common movement shaft which in its turn is assembled rotatable on the relative support frame.
It is also known that this arrangement to support and move the reflection plates used in solar plants is also used in other types of plant, for example photovoltaic plants, transmission and reception plants or others in which it is necessary to orientate a plurality of interception elements, whether they are photovoltaic panels, transceiver antennae or other.
It is known to provide, for all said types of known plants, the rotatable assembly of each shaft to a frame by means of brasses, bearings or other similar rotation mechanisms, advantageously disposed misaligned from the shaft in order to approach as near as possible, with their axis of rotation, to the barycenter of the plates.
In solar plant applications, but not only, it is known that all the support and rotation components are subject to high loads and heat variations, with consequent and coordinated variations in size.
Said variations in size, although they can be partly contained on a unitary scale, do entail in the whole of the plant a considerable dimensional range, in particular in a direction longitudinal to the shaft.
This dimensional range is particularly critical in correspondence with the rotation mechanisms, since it may cause the loss of design tolerances and stresses that cannot be sustained for long periods by the rotation mechanisms.
It is known to use oblique rolling bearings or similar in order to exploit their transverse tolerance and to support even light transverse loads.
This type of known bearing, as well as being more costly, does not however allow to support the loads and the transverse displacements of these applications, due to the heat variations.
Moreover, both in the solutions which use brasses and also in the solutions which use oblique rolling bearings torsion stresses may occur, distributed progressively along the length of the plant. The formation of said torsion stresses determines a loss in uniform positioning of the interception elements, thus varying the conditions of use and the correct functioning of the plant.
Purpose of the present invention is to achieve a movement mechanism and to perfect a solar plant, which are simple and economical to produce, and which allow to move efficiently and precisely the interception elements supporting the transverse loads due to thermal dilations, and not only.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

BRIEF SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.
In accordance with the above purpose, a movement mechanism according to the present invention is advantageously applied to move at least an interception element of a solar plant, for example of the concentration type; the plant comprises, as well as an interception element, a support frame on which the interception element is assembled mobile in order to assume an optimized interception condition, for example exposure to the sun's rays.
The movement mechanism according to the present invention is assembled on the support structure, and is constrained to one or more interception elements in order to move them with respect to the frame.
The movement mechanism comprises a fixed body assembled on the support structure, a rotating body assembled rotatable inside the fixed body around an axis of rotation and constrained to the interception elements.
The movement mechanism also comprises a plurality of rolling members, such as balls, rolls, rollers or other, disposed between relative sliding tracks. The sliding tracks are made annularly both on the fixed body and on the rotating body, substantially concentric to the axis of rotation, in order to promote the rotation conditions of the rotating body with respect to the fixed body.
According to a characteristic feature of the present invention, the movement mechanism comprises at least a compensation seating made on the fixed body and/or on the rotating body and extending with respect to the sliding tracks in a direction substantially parallel to the axis of rotation, in order to define a controlled play of axial displacement of the rolling members.
In this way, a possible dimensional variation of the fixed body and/or the rotating body, due for example to a heat variation, is assisted by the movement of the rolling members inside the play defined by the relative compensation seatings, substantially without varying the mechanical conditions of rotation of the rotating body and the fixed body.
With the present invention the efficiency and precise movement of the interception elements is therefore guaranteed in a simple and economic manner, even in the case of transverse loads on the movement mechanisms, due to heat variations and not only.
Moreover the possibility of movement of the rolling members inside the play defined by the compensation seatings allows to reduce to a minimum the possible torsion stresses, improving the conditions and the precision of rotation applied.
According to a variant, the fixed body comprises at least a ring-nut attached radially to the fixed body and on which the relative sliding track is made.
In this variant, a first solution provides that the compensation seating is made on the ring-nut at least on one side of the relative sliding track.
A second solution of this variant provides that the compensation seating is made directly on the fixed body and that the ring-nut is disposed axially mobile inside the compensation seating.
According to another variant, the sliding seating is made on the rotating body.
According to a further variant, elastic contrast means are provided inside the compensation seating, for example made of elastomer, or mechanical such as springs or other, which allow to at least partly absorb the movement due to the heat variations.
According to a further variant, the fixed body provides one or more attachment elements, integrated to it, in order to allow the direct or indirect attachment of the interception elements to the movement mechanism.
By indirect attachment we mean, for example, a solution in which the rotating body is attached to a displacement element which defines a substantially cam connection with the interception element, allowing to bring the axis of rotation of the rotating body as near as possible to the barycenter of the interception element.
According to a variant, the solar plant also comprises a drive member kinematically connected to the movement mechanism in order to command the rotation of the rotating body.
According to another variant, the solar plant comprises at least a position transducer member, such as an encoder, operatively connected to the rotating body of the movement mechanism in order to control the rotation parameters thereof.
According to a further variant, the solar plant comprises a command and control unit able to coordinate, according to definable and/or predefined operating parameters, the activity of the drive member in relation to the data detected by the position transducer member.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein:

FIG. 1 schematically shows a three-dimensional view of a part of a concentration solar plant according to the present invention;

FIG. 2 shows a lateral view of a concentration solar plant according to the present invention;

FIG. 3 shows a movement mechanism according to the present invention, partly sectioned, of the type applied to the plant in FIG. 2;

FIG. 4 shows a first variant of FIG. 3;

FIG. 5 shows a second variant of FIG. 3;

FIG. 6 shows a third variant of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the attached drawings, a solar plant 10 according to the present invention in this case is of the concentration type, that is, one in which the sun's rays are concentrated toward suitable collectors 13, inside which a saline solution flows which functions as an energy accumulator. The energy thus accumulated is then transformed into usable energy, such as electric, thermal energy or other.
In particular the solar plant 10, according to the present invention comprises a plurality of reflection plates 11 and a support frame 12 on which the reflection plates 11 are assembled, according to a desired order.
The solar plant 10 also comprises a plurality of movement mechanisms 15 suitable to selectively move the reflection plates 11, individually or in groups, with respect to the support frame 12.
Each reflection plate 11 substantially consists of one or more mirrors disposed reciprocally to define a structure conformed substantially concave in order to reflect the sun's rays toward the collector 13.
Advantageously the collector 13 is positioned in correspondence with the point of focus defined by the mirror or mirrors which make up the reflection plate 11.
The support frame 12 comprises a plurality of support pedestals 16 attached to the ground and distanced with respect to each other in an orderly manner at a predefined distance. In a non-restrictive example, said distance is about 10-15 meters.
The support frame 12 comprises in this case a plurality of support shafts 17 disposed between the support pedestals 16, and on which the reflection plates 11 are able to be directly assembled.
As will be explained hereafter in detail, each support shaft 17 is assembled mobile on the support pedestals 16 by means of relative displacement rods 19, attached to the ends of the relative support shaft 17 and in their turn attached to a relative movement mechanism 15.
Each movement mechanism 15 comprises a base 20 attached to a relative support pedestal 16 and to a rotating shaft 21 assembled rotatable around an axis of rotation X, on the base 20.
In particular, the base 20 comprises a through hole 22 having a shape and sizes coordinated to those of the rotating shaft 21, so as to allow the through housing thereof inside it, with the possibility of rotating freely.
The movement mechanism 15 also comprises two crowns of rolling rollers 23, interposed, at a desired distance with respect to each other, between an external surface of the rotating shaft 21 and the through hole 22 of the base 20.
The crowns of rolling rollers 23 allow to improve the rotation conditions of the rotating shaft 21 inside the through hole 22.
The rotating shaft 21 also comprises on each head end, a plurality of attachment holes 24, in which by means of known attachment systems, for example, screws, bushings or other, the displacement bracket 19 is attached.
The attachment thus made by means of the displacement bracket 19 defines a misaligned or substantially cam-type conformation of the support shaft 17 and the rotating shaft 21, so as to bring the axis of rotation X as near as possible to the barycenter of the reflection plates 11, so as to have an optimized rotation condition of the latter.
In particular, on the external surface of the rotating shaft 21 relative sliding tracks 25 are directly made, annular and concentric to the axis of rotation X.
Inside each sliding track 25 the rolling rollers 23 roll with precision.
The base 20 comprises a pair of ring-nuts 26, which are disposed substantially parallel with respect to each other and concentric to the axis of rotation X.
On each ring-nut 26 a relative sliding track 27 is made, opposite and aligned to the relative sliding track 25 of the rotating shaft 21, on the opposite side with respect to the relative crowns of rolling rollers 23.
Each movement mechanism 15 also comprises one or more compensation seatings 30 which extend from both sides with respect to the sliding tracks 25 or 27, parallel to the axis of rotation X, in order to define an axial play of movement of the crowns of rolling rollers 23.
In the form of embodiment shown in FIG. 3, two compensation seatings 30 are provided, which are made on the ring-nuts 26 as a lateral extension of the sliding tracks 27.
In this solution, a possible dilation, or possible contraction due to different thermal loads, determines the axial movement of the crowns of rolling rollers 23 inside the relative compensation seating 30.
In the form of embodiment in FIG. 4 on the contrary, a single compensation seating 30 is provided, made directly on the base 20 and inside which the two ring-nuts 26 are disposed axially sliding.
In this solution, a possible dilation or possible contraction due to different thermal loads, determines the axial movement of the ring-nuts 26 with the relative rolling rollers 23 inside the compensation seating 30.
In the form of embodiment in FIG. 5, the compensation seating 30 is made on the base 20 as in the solution in FIG. 4. In this solution, however, instead of the rolling rollers 23 two crowns of rolling balls 123 are provided.
In particular, in the solution in FIGS. 4 and 5, the compensation seating 30 is defined by an annular element 31 attached by means of screws 32 to the base 20.
This solution allows to make a substantially airtight compensation seating 30, thus reducing to a minimum the maintenance needed and the possible intervention times.
The solar plant 10 also comprises a drive member 33 kinematically connected to the rotating shaft 21 of one of the movement mechanisms 15, so as to determine the controlled rotation thereof.
Since the rotating shafts 21 are kinematically connected with respect to each other by means of the displacement brackets 19 and the support shafts 17, the movement of a rotating shaft 21 results in the rotation of all the rotating shafts 21 of the movement mechanisms 15 provided.
Moreover, the solar plant 10 comprises an encoder 35 connected to one rotating shaft 21, advantageously opposite the one that is kinematically connected to the drive member 33, in order to check the rotation conditions of the rotating shaft 21.
A command and control unit, of the known type and not shown, is provided to coordinate, in a desired way, the activation of the drive member 33 with respect to the data detected by the encoder 35, and other functional parameters, such as the azimuthal angle of the sun or others.
It is clear, however, that modifications and/or additions of parts may be made to the solar plant 10 and to the movement mechanism 15 as described heretofore, without departing from the field and scope of the present invention.
For example, it comes within the scope of the present invention to provide, as shown in the variant in FIG. 6, that the compensation seating 30 is made directly on the external surface of the rotating shaft 21, rather than on the base 20.
It also comes within the scope of the present invention to provide that elastic members, such as springs, elastomers or others are provided inside the compensation seatings, able to absorb the movements of the rolling rollers 23, or of the relative ring-nuts 26, during the dilations and contractions of the rotating shaft 21 and/or the base 20.
It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of movement mechanism and solar plants using said mechanism, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claims

1. A movement mechanism for at least an interception element assembled mobile on a support frame to assume an optimized interception condition, said movement mechanism being able to be assembled on said support frame and to be constrained to said interception element, in order to allow the movement thereof with respect to the support frame, and comprising a fixed body able to be assembled on said support frame, a rotating body assembled rotatable inside the fixed body around an axis of rotation and able to be constrained to the interception element, and a plurality of rolling members disposed rotating between relative sliding tracks made both on the fixed body and also on the rotating body, wherein it comprises at least a compensation seating made on the fixed body and/or on the rotating body and extending with respect to said sliding tracks in a direction substantially parallel to the axis of rotation, to define a controlled play of axial displacement of said rolling members, wherein said fixed body comprises at least a ring-nut (26) attached radially to the fixed body and on which a relative sliding track is made, said compensation seating is made directly on the fixed body and the ring-nut is disposed axially mobile inside said compensation seating.

2. The movement mechanism as in claim 1, wherein the compensation seating is made on the ring-nut at least on one side of the relative sliding track.

3. The movement mechanism as in claim 1, wherein it comprises elastic contrast means provided inside the compensation seating, to at least partly absorb the movement of the rolling members.

4. The movement mechanism as in claim 1, wherein said rolling members comprise at least an annular crown of rolling rollers.

5. The movement mechanism as in claim 1, wherein said rolling members comprise at least an annular crown of rolling balls.

6. A solar plant comprising at least an interception element, a support frame on which said interception element is assembled mobile to assume an optimized interception condition, and at least a movement mechanism assembled on the support frame, and constrained to said interception element, in order to allow the movement thereof with respect to the support frame, said movement mechanism comprising a fixed body assembled on said support frame, a rotating body assembled rotatable inside the fixed body around an axis of rotation and constrained to the interception element, and a plurality of rolling members disposed rotating between relative sliding tracks made both on the fixed body and also on the rotating body, wherein the movement mechanism comprises at least a compensation seating made on the fixed body and/or on the rotating body and extending with respect to said sliding tracks in a direction substantially parallel to the axis of rotation, to define a controlled play of axial displacement of said rolling members, wherein said fixed body comprises at least a ring-nut attached radially to the fixed body and on which a relative sliding track is made, the compensation seating is made directly on the fixed body and the ring-nut is disposed axially mobile inside said compensation seating.

7. The solar plant as in claim 6, wherein the compensation seating is made on the ring-nut at least on one side of the relative sliding track.

8. The solar plant as in claim 6, wherein for each movement mechanism it comprises one or more attachment elements able to allow the direct or indirect attachment of the interception element to the fixed body.

9. The solar plant as in claim 6, wherein it also comprises at least a drive member kinematically connected to the movement mechanism, to command the rotation of the rotating body.

10. The solar plant as in claim 6, wherein it comprises at least a position transducer member operatively connected to the rotating body of the movement mechanism, to control the parameters of rotation thereof.