ES2749455T3 - Transmission system for oscillating systems and steerable antenna comprising said transmission system - Google Patents

Abstract

Transmission system (100) for oscillating systems comprising: - a drive pulley (110) that can be driven in rotation about an axis of rotation of the drive pulley; -a driven pulley (120); - a first and a second flexible transmission element (130A, 130B) operatively coupled to the driving pulley (110) and the driven pulley (120) for the transmission of a movement between said pulleys (110, 120), comprising the flexible transmission elements (130A, 130B) each a first and a second connection portion (131A, 131B, 132A, 132B), each of said first connection portions (131A, 131B) being attached to the pulley (110) motive; and - a connection member (140) including a connection element (36) configured to connect the transmission system (100) to a useful load (4, 5), the connection element (36) being rotatably connected with the pulley (120) driven around an axis of rotation; wherein the drive pulley (110) is adapted to drive the driven pulley (120) and the connecting element (36) in rotation in a first and in a second direction of rotation opposed to each other respectively by the elements (130A, 130B ) first and second flexible transmission; wherein said connecting element (36) is arranged to rotate about the axis of rotation of the driving pulley (110); wherein said transmission system (100) further comprises a part (150) fixed with respect to said driven and driven pulleys (110, 120), said second connection portions (132A, 132B) being joined to said part (150) fixed; wherein said axis of rotation about which the driven pulley (120) and the connecting element (36) are rotatably integral is the axis of rotation of the driving pulley (110); said transmission system (100) being characterized in that: said transmission system (100) furthermore - comprises a coupling shaft (170) connected to the driven pulley (120) and to the connection member 35 (140) for coupling the pulley ( 120) driven to the connecting member (140), the driven pulley (120) being coupled to the coupling shaft (170) so that it can rotate about an axis of rotation of the driven pulley (120) that is parallel to the axis of rotation of the driving pulley (110); in which said transmission system (100) has a transmission ratio ρ that can be obtained as follows: ** Formula ** in which Rc is the radius of the path of the center or axis of rotation of the pulley (120 ) driven, Rm is the radius of the driving pulley (110), T is a shot on the first transmission element (130A) and Tc is the effective component of the resultant of the shots T acting on the driven pulley (120) .

Description

DESCRIPTION

Transmission system for oscillating systems and steerable antenna comprising said transmission system

This description refers to a transmission system for oscillating systems and to a steerable antenna comprising said transmission system.

With reference for example and in a non-limiting manner to the field of servo-assisted kinematic motion systems used in the field of missiles (gimbals), there is frequently the problem of transmitting motion to a payload, which in the specific case comprises a radio frequency antenna (RF), so that extreme precision in aiming is ensured, high angular accelerations, absolute absence of slack throughout the powertrain, even with external disturbances, such as free flight vibrations and impact of exit and maneuver.

The kinematic chains used for these purposes are of different types, each with its particularities, advantages and disadvantages. In the case where the transmission ratio is direct, these kinematic mechanisms have either direct connections to the suitable motor shafts to allow the movement of the payload or rigid intermediate mechanical controls of various types.

In cases where the upstream torque is not sufficient to guarantee the required angular accelerations, it is necessary to use mechanisms with transmission ratios.

To this end, mechanics provides various solutions, such as gears and belt and pulley drives, among others.

In the case of high-performance missile aiming gimbal servo mechanisms, complications are added to the simple reduction function due to the need to guarantee almost absolute uniqueness of the transmission position (which cannot be obtained with elastically deformable transmission elements such as drive belts, or slip transmission elements such as contact pulleys), an almost absolute absence of slack (which cannot be obtained with regular chain drive gear), low friction and low resistance torque (which cannot always be obtained from the classic systems mentioned above).

A type of the known prior art transmission system suitable for providing the general requirements for stiffness, uniqueness of transmission, absence of slack and low friction that allows to meet, at least partially, the aforementioned need, is represented by a system of pulley and belt transmission, metallic. In practice, such a transmission system is based on a transmission that is mechanically similar to a rigid belt (metal band) transmission system that interacts on fixed and moving non-contact pulleys.

In a pulley and belt system, simple mechanical elements such as metal pulleys and belts are used, the latter normally being made of harmonic steel. The belts appear to be steel belts whose purpose is to transfer movement from the drive pulley to the driven pulley.

The movement is therefore transferred from the band whose rigidity at this tension is such that it is considered rigid and with such deformations that they are incomparable with the required precision.

In its simplest embodiment, a metal belt and pulley transmission system of the aforementioned type comprises a driving pulley, a driven pulley with which a connection element (such as, for example, a connection flange) is connected to connect the transmission system to a payload, and a pair of metal bands. Specifically, the drive pulley and driven pulley are suitable for each to rotate about a respective fixed axis of rotation. The two belts each have one end attached to the drive pulley and an opposite end attached to the driven pulley and are arranged so that they intersect in the space between the drive pulley and the driven pulley. When the drive pulley rotates around the respective axis of rotation, the driven pulley and the connecting element integral with it are driven in rotation by the bands around the axis of rotation of the driven pulley. During the rotation of the driving pulley, the drag is guaranteed only by one of the two bands, that is, the band that works in traction.

A drawback of this type of belt and pulley transmission system is represented by the fact that such a transmission system is relatively bulky. This drawback is particularly relevant in the event that the space available for the installation of the transmission system is particularly small, as is the case, for example, and not limitingly in the case where the transmission system must be installed in the radome of a missile.

Another type of transmission system comprising a concentric pulley drive is known from from U.S. Patent No. 4,484,486.

A general purpose of this disclosure is to make available a drive system for oscillating systems that can at least partially overcome the drawback described above with reference to the known art.

This and other purposes are achieved by a transmission system as defined in the main claim in its most general form, and in the dependent claims in various particular embodiments.

This invention also covers a transmission group as defined in claim 10.

This invention also covers a steerable antenna as defined in claim 11.

This invention also covers a search engine as defined in claim 15.

The invention will be better understood from the following detailed description of its embodiments, provided by way of example and therefore not limiting in any way, in relation to the accompanying drawings, in which:

figure 1 shows a perspective view in partial section of a portion of a missile, comprising a radome and a steerable antenna;

figure 2 shows a perspective view of the steerable antenna of figure 1;

figure 3 shows a first side sectional view of the steerable antenna of figure 1;

figure 4 shows a perspective view of an embodiment of a support bracket of the steerable antenna of figure 1;

figure 5 shows a second side sectional view of the steerable antenna of figure 1, in which the section plane is perpendicular to the section plane of the view of figure 3;

figure 6 shows a perspective view of an enlarged detail of the steerable antenna of figure 1;

figure 7 shows a partial perspective view of a transmission group comprising a transmission system according to a presently preferred embodiment and a motor, this transmission group being represented in a first configuration and being suitable for mounting on the adjustable antenna of figure 1;

figure 8 shows a partial perspective view of the group of figure 7 in which the transmission system is partially shown in section;

figure 9 shows a partial perspective view of the group of figure 7 represented in a second configuration;

figure 10 shows a partial perspective view in section of the transmission group of figure 7; figure 11 shows a perspective view of a component of the transmission system of figure 7; Y

figure 12 shows a schematic and partial plan view of the transmission system of figure 7, in which said transmission system is represented in a plane orthogonal to the axis of rotation of the respective drive pulley.

In the attached figures, the same or similar elements will be indicated by the same reference numbers. Note that the terms "axial", "radial" and "circumferential" used to describe the structure or operation of a transmission system according to this description, or its parts, are to be understood as referring to the axis of rotation of a drive pulley of this transmission system.

Figure 1 shows a portion of an embodiment of a missile 1 comprising a radome 2 and a steerable antenna 3 mounted within radome 2. In the particular example depicted and without thereby introducing any limitation, the steerable antenna 3 is the antenna of a radar and more particularly the antenna of a missile seeker. It should be noted, however, that the teachings of this disclosure can be applied without limitation with respect to the particular type of steerable antenna, since the steerable antenna of this disclosure could be any antenna that can be used for example in the fields of telecommunications, terrestrial or satellites, and scientific measurement instrumentation.

The steerable antenna 3 comprises a payload 4.5, preferably a payload 4.5 steerable. For example, the steerable payload 4,5 comprises at least one device 4 for receiving and / or transmitting electromagnetic radiation. For example, the electromagnetic radiation receiving and / or transmitting device 4 comprises a flat array of antennas for example a microwave disk antenna comprising a plurality of antenna elements, for example patch antenna elements or slot antenna elements . Preferably, and without thereby introducing any limitation, the electromagnetic radiation receiving and / or transmitting device 4 is both a receiving and transmitting device.

According to one embodiment, the payload 4,5 also a section 5 of a circuit for processing the signals transmitted and / or received by the device 4 for receiving and / or transmitting electromagnetic radiation.

According to a preferred embodiment, the steerable antenna 3 also comprises an electromechanical support and movement system 6-10 operatively connected to the payload 4,5 and suitable for orienting the payload 4,5 in a controlled manner.

According to a preferred embodiment, the electromechanical support and movement system 6-10 comprises a base 6 and preferably a first motor 7 (or external motor 7) fixed to the base 6. Preferably, the electromechanical support and movement system 6-10 comprises a first driven pulley 8 operatively coupled to the first motor 7 to be rotated about a first axis of rotation (or outer axis of rotation). According to an embodiment, the steerable antenna 3, and more preferably the electromechanical support and movement system 6-10 comprises a second motor 9 (or internal motor 9). According to an embodiment, the second motor 9 is operatively coupled to the first pulley 8 driven and operatively connected to the payload 4,5 to rotate the payload 4,5 around a second axis of rotation (or axis of internal rotation). The first and second axis of rotation are perpendicular to each other.

The electromechanical support and movement system 6-10 also includes a support bracket 10, for example as shown in Figure 3, integral with the base 6 and to which the second motor 9 is pivotally articulated.

The first driven pulley 8 is operatively connected to the second motor 9 to rotate the second motor 9 with respect to the base 6 and with respect to the support bracket 10.

Preferably, the first 7 and second 9 motors are servo motors.

According to an embodiment, the base 6 is a cylindrical, or substantially cylindrical, container provided with a first opening 12 or upper opening 12 and a lower opening 13 or second opening 13. Preferably, the base 6 comprises a housing 14 in which it houses and fixes the first motor 7. Preferably, the steerable antenna 3 comprises an electronic control circuit 15 of the first motor 7 also at least partially housed in the housing 14.

According to an embodiment, the base 6 comprises one or more fixing elements 16 suitable to allow the fixing of the base 6 within the radome 2. For example, these fixing elements 16 comprise a plurality of recesses defined in the outer side walls of the base 6.

According to an embodiment, the upper opening 12 of the base 6 allows the passage of at least one movement transmission element from the first motor 7 to the first driven pulley 8.

Referring to Figure 4, according to one embodiment, the support clamp 10 comprises a first end portion 20.21 solidly attached to the base 6 and a second end portion 22.23 to which the second motor 9 is pivotally hinged. For example, the first end portion 20,21 is fixed to the base by screws going through through openings provided in the first end portion 20,21 to insert into corresponding internally threaded openings or holes provided in the upper wall of the base. 6.

Preferably, the support bracket 10 is fork-shaped, and the second end portion 22,23 comprises two end portions between which the second motor 9 is pivotally hinged.

More preferably, said first end portion 20,21 of support bracket 10 comprises at least one leg for attachment to base 6 provided with a through opening 26 pierced by first driven pulley 8 and which does not interfere with rotation of driven pulley 8. In the example of FIG. 3, said fixing leg 20.21 comprises two fixing legs 20,21 separated and between which the said through opening 26 crossed by the first driven pulley 8 is defined.

According to a further embodiment, the support clamp 10 comprises two fork arms 24,25 fixed to the fixing leg 20,21 of the support clamp 10 and the said second end portions 22,23 are free end portions of said fork arms 24.25. Preferably each of said second end portions 22,23 of support bracket 10 comprises a respective through opening 28,29 of circular cross section. These through openings 28,29 define an articulation axis and allow the second motor 9 to pivotally articulate to the support clamp 10.

According to one embodiment, the support clamp 10 comprises a waveguide 30 integrated within the clamp 10.

Preferably, the waveguide 30 is a channel defined in the thickness of the support clamp 10 and this clamp 10 is made of a metallic material, for example steel.

With reference to Figure 4, according to an advantageous embodiment, the support clamp 10 comprises two half portions 27,28 made in two different portions and juxtaposed and coupled together, for example by screws. In this way, the realization of the waveguide 30 integrated in the support bracket 10 is particularly simple, since the waveguide 30 can be obtained by providing a first recess in one wall of one of the two half portions 27,28 intended to face a wall opposite of the other of the two half portions. Obviously, a second recess can also be provided in said opposite wall that is opposite and aligned with the first recess when the two half portions 27,28 are coupled together. In the case where the support clamp 10 is fork-shaped with the two fork arms 24,25, the said channel preferably has a portion extending within one of said fork arms 24,25. Preferably, said channel extends between two channel openings from the first end portion 20,21 of the support bracket 10 to the second end portion 22,23 of the support bracket 10 such that a waveguide 30 is defined. extending from the base 6 of the adjustable antenna 3 to the payload 4,5. A waveguide connector may be provided in the base 6 arranged in correspondence of the respective channel opening.

Referring to Fig. 3, according to one embodiment, the steerable antenna 3 comprises a first rotary waveguide joint 31 having a joint portion attached to the support bracket 10, corresponding to the second end portion 22,23 which is operatively coupled to the integrated waveguide 30 and is in operational communication with the latter and a second gasket portion operatively coupled to the payload 4.5. Preferably, the second motor 9 is attached to the second rotary waveguide seal portion, in the example shown outside it. With joint reference to Figures 3 and 5, in the particular example shown, the first rotary waveguide joint 31 is fixed to the arm 25 of the support bracket 10 and in particular hooked in the passage of the through opening 29 and, from this In this way, it allows the second motor 9 to be pivotally articulated to the arm 25 of the support clamp 10. Preferably, a hinge pin 32 is provided on the other side of the support bracket 10 including a portion with a smooth surface engaged in the second motor 9 and a threaded portion threaded into the through opening 28 of the arm 24 of the bracket 10 of support.

The second motor 9 comprises a motor shaft 35. According to a preferred embodiment, the second motor comprises a container body 39 and preferably a stator 33 housed within the container body 39 and a rotor 34. In this case, the motor shaft 35 is preferably fixed or coupled to the rotor 33. In a preferred embodiment, the container body 39 is attached to the first driven pulley 8 and pivotally hinged to the support bracket 10 to be able to rotate about the first axis of rotation. The motor shaft 35 of the second motor 9 is coupled to the payload 4,5 by means of a connection element 36, preferably a first coupling flange 36 or connection flange 36.

According to an embodiment, a speed and / or position transducer 45 is coupled to the motor shaft 35 of the second motor 9 with the motor shaft 35 in its rotation about the second axis of rotation.

According to one embodiment, the payload 4,5 is coupled to the outer container 39 of the second motor 9 by a second coupling flange 37 and a second rotary joint 41, shown in Figure 5. Preferably the second rotary joint 41 and the flange 37 Coupling devices are waveguide devices and allow a waveguide connection to be made by means of a connection waveguide 38, operatively interconnected between the first waveguide seal 31 and the second waveguide 41 and integrally rotatable with the second motor 9.

Referring to Fig. 5, according to one embodiment, the first driven pulley 8 has an arc-shaped central portion 50 and two lateral arms 51,52 attached to the container body 39 of the second motor 9. The rotation of the first pulley 8 driven therefore determines a rotation of the container body 39 of the second motor 9 about the first axis of rotation.

According to one embodiment, the first motor 7 comprises a container body 70, a stator 71 housed within the container body 70, a rotor 72 and a motor shaft 73 fixed or coupled to the rotor 72. The container body 70 is fixed to base 6. According to one embodiment, a speed and / or position transducer 74 is coupled to the motor shaft 73 of the first motor 7.

According to an embodiment, the motor shaft 73 of the first motor 7 is preferably directly coupled, that is, without transmission reduction gear, to the first driven pulley 8.

According to a preferred embodiment, the electromechanical support and movement system 6-10 comprises a band transmission system 18,19,48,49, and more preferably a metal band transmission system 18,19,48,49, suitable for operatively coupling the first motor 7 to the first driven pulley 8 comprising two bands 18,19 crossing each other having a first end portion attached to the first driven pulley 8, wherein said system 18,19, 48.49 transmission comprises a first pulley 48,49 drive coupled to the first engine 7, and in particular to its engine shaft 73. The said bands 18,19 each have a second end portion attached to the first drive pulley 8. Preferably, the second end portions of the bands 18,19 are attached to opposite end portions 53,54 of the central portion 50 with arc shape of the first driven pulley 8.

According to an embodiment, said bands 18,19 are made of a metallic alloy, for example a superalloy with an austenitic nickel-chrome structure. Preferably such strips have a reduced thickness, for example on the order of one tenth of a millimeter, for example equal to one tenth of a millimeter.

According to an embodiment, the first driving pulley 48,49 comprises two parallel pulleys 48,49, fixed to each other by means of a coupling system that allows adjusting the mutual orientation of said pulleys 48,49 to guarantee correct prestressing of the belts 18,19 .

Figures 7 to 10 partially show a transmission group 100.9 according to a presently preferred embodiment. The transmission group 100.9 is also shown in section in FIG. 5. According to a preferred embodiment, the transmission group 100.9 comprises a transmission system 100 for oscillating systems (ie, suitable for moving a payload, from periodically or non-periodically, between two different angular positions) coupled to the second motor 9. In this sense, note that the applications of a transmission system 100 and a transmission group 100,9 according to this description are not limited to the sector of steerable antennas. In fact, a transmission system 100 according to this description can be applied to a variety of oscillating systems in which it is necessary to have a different transmission ratio from the unit, and in particular a reduction ratio. In general, the teachings regarding the transmission system 100 and the transmission group 100.9 according to this description can be applied to any oscillating system in which it is necessary to have a different transmission ratio from the unit. According to a preferred embodiment, the transmission system 100 is a transmission reduction gear.

Transmission system 100 comprises a second drive pulley 110 that can be driven in rotation about an axis of rotation of the second drive pulley 110. According to an embodiment, the axis of rotation of the second drive pulley 110 coincides with the axis of rotation of the motor shaft 35 of the second motor 9. Preferably, the second motor pulley 110 is integral in rotation with the motor shaft 35 of the motor 9 In other words, the drive pulley 110 can be rigidly connected to the drive shaft 35 or alternatively can be formed in one piece with such a drive shaft 35.

Transmission system 100 comprises a second driven pulley 120. Furthermore, the transmission system 100 comprises a first and a second flexible transmission element 130A, 130B operatively coupled to the second drive pulley 110 and the second driven pulley 120 for transmission of movement between such pulleys 110,120. According to a preferred embodiment, the first and second transmission element 130A, 130B respectively comprise a first and a second metallic band 130A, 130B, which are preferably made of harmonic steel. The fact of making the first and second transmission element 130A, 130B in the form of metal bands conveniently makes it possible to guarantee the rigidity of the transmission, low friction and total, or almost total, absence of play. As an alternative to metallic belts 130A, 130B, a first and a second steel cable can be used, which are also suitable to ensure equivalent transmission stiffness, low friction and total, or almost total, absence of slack. In the case where the transmission system 100 is used for applications that have less stringent requirements for transmission stiffness, low friction, and no slack, relative to, for example, applications on the steerable antennas of a search engine, missiles, as an alternative to metal bands, other flexible transmission elements such as, for example and not limited to, belts, chains, ropes, non-metallic cables and, in general, additional flexible transmission elements that may have a greater elasticity than metal bands.

The first transmission element 130A comprises a first and a second connection portion 131A, 132A. The second transmission element 130B comprises a first and a second connection portion 131B, 132B. Preferably, the first and second connecting portions 131A, 132A and 131B, 132B are end portions of transmission elements 130A, 130B. Each of the first connecting portions 131A, 131B is preferably removably attached to the drive pulley 110. Preferably each of the first connecting portions 131A, 131B comprises a first connecting pin 131A, 131B which is attached directly to the drive pulley 110 by axial insertion into a respective cavity provided in the drive pulley 110 and partially shaped contrary to the connecting pin 131A, 131B to prevent disengagement of pin 131A, 131B in the radial direction.

Transmission system 100 comprises a portion 150 fixed with respect to second drive pulley 110 and second driven pulley 120. The second connection portions 132A, 132B are preferably removably attached to the fixed portion 150. According to a preferred embodiment, the second connection portion 132B comprises a second connection pin 132B which is fixed directly to the fixed part 150 by axial insertion into a respective cavity provided in the fixed part 150 and partially shaped contrary to the second pin 131B coupling to prevent disengagement of pin 132B in the radial direction. According to a preferred embodiment, the transmission system 100 comprises a tensioning device 160 that can be attached to the fixed part 150 and suitable for prestressing the first and second flexible transmission element 130A, 130B. Preferably, the second connection portion 132A is indirectly attached to the fixed portion 150 by the tensioning device 160. Referring to Fig. 8, the second connection portion 132A preferably comprises a second connection pin 132A which is preferably fixed to the fixed part 150 by axial insertion into a respective cavity provided in the tensioning device 160 and partially conformed with respect to to the second connecting pin 132A. In particular, the second connecting pin 132A is interposed between the tensioning device 160 and the fixed part 150 so that it is fixed to the fixed part 150. According to a preferred embodiment, the tensioning device 160 is preferably coupled to an axially protruding portion of the fixed part 150. Preferably, the tensioning device 160 is coupled to the fixed part 150 so that it slides relative to the fixed part 150. For this, the device 160 comprises, for example, at least one rib that is suitable for engaging a corresponding at least one slot 155 (Figure 11) provided in the fixed part 150. Preferably, the tensioning device 160 comprises a pair of ribs suitable for engaging a pair of grooves 155. Preferably, the tensioning device 160 comprises fastening elements 162 suitable for locking the device 160 with respect to the fixed part 150. For example, the fastening elements 162 may comprise a pair of fastening screws 162, each suitable for passing through a respective adjusting slit 163 (a single slit 163 can be seen in figure 7) provided in the tensioning device and for each one is coupled to a respective fixing hole 156 (figure 11) provided in the fixed part 150.

According to an alternative embodiment, in the case where less precision of the transmission position is required, the tensioning device 160 may not be provided and the second connection portion 132A can be fixed directly to the fixed part 150. In particular, the second connection portion 132A may comprise said second connection pin 132A, which, analogously to the second connection pin 132B, can be inserted axially in a respective cavity provided in the part 150 fixed and partially shaped contrary to respect to the second coupling pin 132A so that radial decoupling of the second connecting pin 132A is avoided.

Always referring to Figures 7 to 10, the transmission system 100 comprises said connection element 36 or connection flange 36, for connecting the transmission system 100 to the payload 4,5. The connecting element 36 is arranged to rotate about the axis of rotation of the driving pulley 110. More particularly, the connecting element 36 is restricted so that it can rotate exclusively around the axis of rotation of the second driving pulley 110. The connection element 36 is integral in rotation with the second pulley 120 driven around the axis of rotation of the driving pulley 110. The driving pulley 110 is suitable for driving the second driven pulley 120 and the connecting element 36 in rotation in a first direction of rotation (indicated by arrow A1 in Figure 9) and in a second direction of rotation opposite each other respectively by the first and second flexible transmission element 130A, 130B. In particular, the second driven pulley 110 is suitable for driving the second driven pulley 120 and the connecting element 36 in rotation about the axis of rotation of the driving pulley 110.

Note that during rotation of the driven second pulley 120 and connecting element 36 in one of said first (arrow A1) and second direction, pull is assured by only one of said first and second transmission element 130A, 130B, and more particularly by the transmission element 130A, 130B that works in traction. For example, during the rotation of the driven pulley 120 about the axis of rotation of the drive pulley 110 in the direction of arrow A1 in FIG. 9, the pull is assured only by the first flexible transmission element 130A.

According to an embodiment, the second driven pulley 120 and the connecting element 36 are suitable for rotating between a first and a second angular position different from each other and angularly separated around the axis of rotation of the driving pulley 110. In Figure 9, the driven pulley 120 and connecting element 36 are shown in the first angular position. In Figures 7 to 8, the driven pulley 120 and connecting element 36 are shown in a central angular position that is intermediate between said first and second angular position (this second angular position is not shown in the figures). Even in the schematic representation of Figure 12, the driven pulley 120 is illustrated in said central angular position, which is intermediate between the first and second angular position. According to a preferred embodiment, the first and second angular positions that the pulley 120 and the connecting element 36 can assume are angularly separated from each other by an angle of less than 180 ° and more preferably by an angle of less than approximately 120 °. In the example, these first and second angular positions are angularly separated from each other by an angle of about 105 °.

According to a preferred embodiment, the connecting element 36 is rotatably adjusted to the fixed part 150 to rotate about the axis of rotation of the driving pulley 110.

With cross reference to Figures 7 to 10 and Figure 11, according to a preferred embodiment, the fixed part 150 comprises a fixed bearing 150 that is coaxial with and extends around the drive pulley 110. Bearing 150 Fixed comprises a through bearing opening 151 interposed between the drive pulley 110 and the driven pulley 120 to allow passage of the first and second flexible transmission element 130 ^a , 130B between the drive pulley 110 and the driven pulley 120. According to a preferred embodiment, the fixed bearing 150 comprises a fixing flange 157, preferably an annular fixing flange 157, for fixing the fixed bearing to the container body 39 of the second motor 9.

Referring to Fig. 11 and the schematic representation of Fig. 12, according to a preferred embodiment, the fixed bearing 150 comprises a radially inner face 152A and a radially outer opposite face 152B. Preferably, the first and second flexible transmission element 130A, 130B each consecutively comprise a first section 133A, 133B wound on the drive pulley 110 and interposed between the drive pulley and the radially inner face 152A of bearing 150, a second section 134A, 134B extending into a space between the drive pulley 110 and driven pulley 120, a third section 135A, 135B wound on driven pulley 120 and a fourth section 136A, 136B partially wound on radially outer face 152B of bearing 150. As it can be seen for example in figure 12, the second section 134A of the first transmission element 130A and the second section 134B of the second transmission element 130B intersect in said space present between the driving pulley 110 and the driven pulley 120.

According to an embodiment, the transmission system 100 comprises a connection member 140 that includes said connection element 36. The connection member 140 comprises an annular coupling portion 142 for coupling the connection member 140 to the fixed bearing 150. The annular coupling portion 142 is coaxial to the drive pulley 110 and defines a coupling opening 144 crossed by the fixed bearing 150.

Referring to Fig. 10, according to one embodiment, the transmission system 100 comprises a coupling shaft 170 connected to the driven pulley 120 and connecting member 140 for coupling the driven pulley 120 to the connecting member 140. Preferably, the driven pulley 120 is coupled to the coupling shaft 170 so that it can rotate about an axis of rotation of the driven pulley 120 that is parallel to the axis of rotation of the drive pulley 110. According to one embodiment, the driven pulley 120 and the connection member 140 are coupled to the connection shaft 170 and to the fixed bearing 150 respectively by at least a first and at least a second backlash coupling bearing 121,143. For example, the at least one first bearing coupling 121 comprises a first pair of opposing oblique contact bearings 121 and the at least one second coupling bearing 143 comprises, likewise, a second pair of opposing oblique contact bearings 143.

Referring to Fig. 11, according to a preferred embodiment, the fixed bearing 150 comprises a first and a second axially extending edge 153A, 153B delimiting the opening 151. Preferably, the fixed bearing 150 comprises a first and a second portion 154A , 154B of support projecting respectively from the first 153A and from the second edge 153B and being circumferentially offset from each other. The first and the second transmission element 130A, 130B are suitable to rest respectively on the first and second support portion 154A, 154B when the driven pulley 120 respectively assumes said first and second angular position.

Having described the structure of the transmission system 100, a non-limiting exemplary mode of operation of such systems is now described with reference to the embodiment illustrated in the accompanying figures.

Suppose that, starting from the configuration of Figures 8 or 12, the motor shaft 35 of the second motor 9 drives the driving pulley 110 in rotation in the direction of rotation opposite the direction of rotation indicated by arrow A1 in Figure 9. This rotation causes the first band 130A to drag, which begins to wind on the driving pulley 110. This rotational movement induces a reduction in the free length of the first band 130A (i.e. of the second section 134A of the band 130A), band 130A having the respective second connection portion 132A attached to the fixed bearing 150. Consequently, driven pulley 120 and connecting flange 36 are induced to rotate about the axis of drive pulley 110 in the direction indicated by arrow A1 in Figure 9. Note that there is no slippage on driven pulley 120 because this pulley 120 can rotate on itself around the respective axis of rotation.

The transmission ratio of the transmission system 100 depends on the size of the driven and driven pulleys 110,120 and the distance of the respective axes of rotation or their respective centers. Specifically, with reference to figure 12, indicating with Rc the radius of the path of the center or axis of rotation of the driven pulley 120, (this path and the radius Rc are represented by broken lines in figure 12), with Rm the radius of the driving pulley 110 (the radius Rm is represented by a broken line in figure 12), with T a shot on the first band 130A (figure 12 shows the shot in the case of a counterclockwise rotation of the driving pulley 110 ) and with Tc the effective component (i.e., the component tangential to the path of the center or axis of rotation of the driven pulley 120) of the resultant of the shots T acting on the driven pulley 120, the transmission ratio p of the transmission system 100 can be obtained as follows:

Tc ^* Rc

p = ----------- T * Rm

Based on the above, it is therefore possible to understand how a transmission system of the type described above allows the above-mentioned purposes to be achieved with reference to the prior art.

In a transmission system 100 according to this description, the connection flange 36 is suitable for rotating around the axis of rotation of the driven pulley 110 instead of around the axis of rotation of the driven pulley 120, which conveniently allows to obtain a relatively compact and space-saving compared to the prior art belt and pulley drive system described above.

In accordance with one aspect of the invention, also note that the steerable antenna described above has a particularly compact structure and has a high transverse stiffness. In fact, the entire system is developed around a rigid central body consisting of the support bracket 10 and the base 6. Furthermore, the embodiment that provides a waveguide integrated in the support bracket 10 is particularly advantageous since it is possible to avoid the provision of a radio frequency cable that moves during maneuvers of the steerable antenna.

Without prejudice to the principle of the invention, the forms of implementation and the details of construction may be varied widely with respect to what has been described and illustrated purely by way of non-limiting example, without thereby departing from the invention as defined in the appended claims.

Claims (1)

Transmission system (100) for oscillating systems comprising: - a driving pulley (110) that can be driven in rotation about an axis of rotation of the driving pulley; -a driven pulley (120); - a first and a second flexible transmission element (130A, 130B) operatively coupled to the driving pulley (110) and the driven pulley (120) for the transmission of a movement between said pulleys (110, 120), comprising the flexible transmission elements (130A, 130B) each a first and a second connection portion (131A, 131B, 132A, 132B), each of said first connection portions (131A, 131B) being attached to the pulley (110) motive; and - a connection member (140) including a connection element (36) configured to connect the transmission system (100) to a useful load (4, 5), the connection element (36) being integrally rotatable with the pulley (120) driven around an axis of rotation; wherein the drive pulley (110) is adapted to drive the driven pulley (120) and the connecting element (36) in rotation in a first and in a second direction of rotation opposed to each other respectively by the elements (130A, 130B ) first and second flexible transmission; wherein said connecting element (36) is arranged to rotate about the axis of rotation of the driving pulley (110); wherein said transmission system (100) further comprises a part (150) fixed with respect to said driven and driven pulleys (110, 120), said second connection portions (132A, 132B) being joined to said part (150) fixed; wherein said axis of rotation about which the driven pulley (120) and the connecting element (36) are rotatably integral is the axis of rotation of the driving pulley (110); said transmission system (100) being characterized in that: said transmission system (100) in addition - it comprises a coupling shaft (170) connected to the driven pulley (120) and to the connection member (140) for coupling the driven pulley (120) to the connection member (140), the driven pulley (120) being coupled to the coupling shaft (170) so that it can rotate about an axis of rotation of the driven pulley (120) that is parallel to the axis of rotation of the driving pulley (110); wherein said transmission system (100) has a transmission ratio p that can be obtained as follows: Te * re P = / * R um where Rc is the radius of the path of the center or axis of rotation of the driven pulley (120), Rm is the radius of the driving pulley (110), T is a shot on the first transmission element (130A) and Tc is the effective component of the resultant of the T shots acting on the driven pulley (120). Transmission system (100) according to claim 1, wherein the connecting element (36) is rotatably adjusted to the fixed part (150) to rotate about the axis of rotation of the driving pulley (110). Transmission system (100) according to any of the preceding claims, wherein said fixed part (150) comprises a coaxial fixed bearing (150) and which extends around the driving pulley (110), comprising the fixed bearing (150) a through bearing opening (151) interposed between the drive pulley (110) and the driven pulley (120) to allow passage of the first and second flexible drive element (130A, 130B) between the drive pulley (110) and the pulley (120) driven. Transmission system (100) according to claim 3, wherein the fixed bearing (150) comprises a radially inner face (152A) and an opposite radially outer face (152B), and wherein the elements (130A, 130B) of First and second flexible transmission each consecutively comprise a first section (133A, 133B) wound on the driving pulley (110) and interposed between the driving pulley and the radially inner face (152A) of said bearing (150), a second section ( 134A, 134B) extending into a space between the drive pulley (110) and the driven pulley (120), a third section (135A, 135B) wound on the driven pulley (120) and a fourth section (136A, 136B) partially wound on the radially outer face (152B) of said bearing (150), said second sections (134A, 134B) crossing each other in said space between the driving pulley (110) and the driven pulley (120). Transmission system (100) according to claim 3 or 4, wherein the connection member (140) comprises an annular coupling portion (142) for coupling the connection member (140) to the fixed bearing (150), said annular coupling portion (142) being coaxial to the driving pulley (110) and defining a coupling opening crossed by the fixed bearing (150). Transmission system (100) according to any of claims 3 to 5, comprising a tensioning device (160) that can be attached to the fixed bearing (150) and suitable for prestressing said first flexible transmission element (130A, 130B) and second, the second connection portion (132A) of the first flexible transmission element (130A) being attached to the bearing (150) fixed by said tensioning device (160). Transmission system (100) according to claim 5, wherein the driven pulley (120) and the connection member (140) are coupled to the coupling shaft (170) and to the fixed bearing (150) respectively by at least a first and at least a second backlash coupling bearing (121,143). Transmission system (100) according to any of the preceding claims, in which the first and second flexible transmission element (130A, 130B) respectively comprise a first and a second metal band (130A, 130B) or a first and a second steel cable. 9. Transmission system (100) according to any of the preceding claims, wherein said transmission system is a reduction gear. 10. Transmission group (100, 9) comprising a motor (9) including a drive shaft (35) and a transmission system (100) according to any of the preceding claims coupled to said motor (9), said pulley being (110) drive jointly rotated with said drive shaft (35). 11. Steerable antenna (3) comprising a transmission group as defined in claim 10. 12. Steerable antenna (3) according to claim 11, wherein said motor (9) is a second motor (9), said antenna comprising: - said payload (4,5); - an electromechanical movement and support system (6-10) operatively connected to the load (4, 5) useful and adapted to orient the payload in a controlled manner, said electromechanical system comprising a base (6), a first motor (7) attached to the base (6), a first driven pulley (8) operatively connected to the first motor (7) to rotate about a first axis of rotation, said second motor (9) operatively connected to the first pulley (8) driven and operatively connected to the payload (4,5) useful for rotating the payload around a second axis of rotation; Furthermore, the electromechanical support and movement system (6-10) comprises a support clamp (10) fixedly fixed to the base (6) to which the second motor (9) and the first pulley (8) are pivotally articulated. driven is operatively connected to the second motor (9) to rotate the second motor (9) in relation to the base (6) and in relation to the support clamp (10). Steerable antenna (1) according to claim 12, wherein said support bracket (10) comprises a first end portion (20,21) attached to the base (6) and a second end portion (22,23) of end to which the second motor (9) is pivotally articulated. Steerable antenna (1) according to claim 13, wherein said support bracket (10) is fork-shaped, and wherein said second end portion (22,23) comprises two end portions between which it is said second motor (9) pivotally articulated. 15. Seeker comprising a steerable antenna (1) according to any of claims 11 to 14.