DESCRIPTION II Back to description I
Figure 5 is a cross-sectional view of the central driving mechanism. The drawing
shows the drive motor 30 partially hidden behind the housing 22 of the central
driving mechanism.
The cross section shows the worm 31 driving the worm gear 32, said worm gear having a grooved hole for driving the respective grooved shaft 21 placed therein; said grooved shaft drives the row of longitudinal tracking bars 23, while said tracking bars drive the arrays of moving frames along the collector module.
The moving frames of the collector have individual sliding means for allowing the longitudinal displacement of the metal foils due to thermal expansion or wind loads. The shaft 21, for example, can slide within the bearing 33. The bearing 33 is press fitted into the bearing housing 34, which is secured to the support pedestal 20.
The metal foil 1 is secured between the moving frame 4 and the upper support member 36 by securing means, generally a pair of bolts and nuts, placed at both ends of said support structures.
Two thin strips 37 made of a soft material like rubber are placed between the metal foil 1 and the frame 4, and between the metal foil 1 and the upper support member 36 respectively. The drawing also shows the rubber seal 35 which protects the bearing 33 and the rubber cover 38 which protects the driving mechanism.
Both parts of the housing 22 are secured to each other by the stud bolts 39, said housing 22 being firmly secured to the bearing housing 34 by the stud bolts 40.
Figure 6 is a cross section and detail view of both ends of the tracking bar 23.
One end is formed by the external ring 41 and the respective internal part 42 with a grooved hole; both components having corresponding internal and external conical configuration within which the tracking bar 23 ( said bar may be an aluminum tube) is placed and press fitted; the assembly is secured by the securing pin 43.
The other end is formed by the external ring 44 and the respective internal ring 45; both components having corresponding internal and external conical configuration within which the tracking bar 23 is placed. The metal tube is press fitted and secured to the crank 24 by a plurality of stud bolts 46 going across said driving crank, said stud bolts being threaded and firmly secured into the respective threaded holes of said external ring 44.
Figure 7 is a cross-sectional view of the end moving frame with tensioning
means and sliding means. The metal foil 1 is firmly secured between the moving
frame 3 and the upper support member 47 by securing means.
The rubber strips 48 are placed between the metal foil 1 and the frame 3, and between the metal foil 1 and the upper support member 47 respectively.
Said tensioning means comprising a tension spring 53 supported by a pair of support members thereof: a fixed support member 52 secured to the bearing housing 51, and a sliding support member 55 which is supported by the flange of the sliding bar 54, said sliding bar 54 being coaxial with the tension spring 53.
The threaded shaft 49 can slide within the bearing 50 for allowing the longitudinal displacement of the moving frame 3.Such bearing 50 is press fitted into the bearing housing 51, which is secured to the support pedestal 20.
The sliding bar 54 has a threaded hole within which the respective threaded shaft 49 is placed. The tension of the spring 53 may be varied by turning the sliding bar 54 on the respective threaded shaft 49, allowing the adjustment of the axial load of the tension spring 53 and consequently the tensile stress of the metal foil.
When the surface of the metal foil is plane and taut enough for allowing an adequate optically reflective surface, the sliding bar 54 is secured to the sliding support member 55 of the spring 53 by the securing pin 56, thus avoiding the rotation of said sliding bar 54.
Then, when the collector is working the threaded shaft 49 turns within the threaded hole of the sliding bar 54; such sliding bar 54 performs as a simple thrust bearing and supports the axial load of the tension spring 53. The bearings and the sliding bar must be made of an adequate material with low friction coefficient like self-lubricating brass or Teflon.
The drawing also shows the rubber seal 57 which protects the shaft 49 and the rubber seal 58 which protects the sliding bar 54.
Figure 8 is a cross-sectional view of the end moving frame with rotary support
means for supporting the tension of the metal foil 1. The ball bearing 59,
which performs as a thrust bearing, is placed into the bearing housing 60,
said bearing housing being mounted on the edge of the main bearing housing
61. The rotary collar 62 is secured to the shaft 63, said collar pushing on
the thrust bearing 59 with the axial load of the metal foil.
The drawing also shows the bearings 64 and 65 press fitted into the bearing housing 61. The shaft 63 has a grooved end placed into the respective grooved part of the tracking bar 23. The drawing is completed with the rubber cover 66 which protects the grooved shaft 63 and the grooved part of the tracking bar 23.
Figure 9 is a detail view of the securing means of the end moving frames, where higher pressure on the metal foil is needed. The moving frame 2 and the upper support member 47 have reinforcing plates 67 and 68 at both ends of said support structures.
The rubber strips 48 are placed between the metal foil 1 and the frame 2, and between the metal foil 1 and the upper support member 47 respectively. The securing bolts 69 go across said support structures and said reinforcing plates, such bolts with the respective nuts securing firmly said metal foil to said end moving frame.
