Angular positioning module for optical bench

Abstract

Angular positioning module for optical bench. Angular positioning module (1) for the positioning system of an optical bench, the angular positioning module (1) comprising: a fixed frame (5); a rotating shaft (7); a rotary motor (11); a transmission device (17) being provided with a pulley (19) mounted for rotation on the output shaft (13) of the rotary motor (11), a wheel (21) mounted for rotation on the rotating shaft (7), and a cable wound on one side around the pulley (19) and on the other side around the wheel (21) such that the pulley (19) and the wheel (21) are linked by two separate strands of the cable, the rotation of the pulley (19) causing the winding of one strand and the simultaneous unwinding of a second separate strand around the pulley (19) and vice versa. Figure 1

Description

Title of the invention: Angular positioning module for optical bench Field of invention

[0001] The present invention relates to an angular positioning module for a positioning system of an optical bench. Prior art

[0002] An optical bench allows you to aim at a point in space for observation. For example, the optical bench is fixed to the ground and is intended for space observation.

[0003] There are several possible applications for this optical bench such as high-speed satellite tracking, high-speed stellar tracking and monitoring (DIMM), ground / space communication or monitoring of sky quality and stability for observatories.

[0004] An optical axis of the optical bench must be aligned with the target point in space. It is thus necessary for the optical bench to comprise a positioning system intended to move certain parts of the optical bench to allow the alignment of the optical axis and the target point.

[0005] In particular, the positioning system of the optical bench may comprise one or more angular positioning modules. This type of angular positioning module has a rotating shaft set in motion by a motor of the positioning module either in one direction or the other depending on the location of the target point.

[0006] The transmission of the driving force between the motor and the shaft can be carried out by a gear or worm wheel mechanism. This mechanism is satisfactory in that it allows transmission in both directions of rotation of the rotating shaft.

[0007] The use of such a transmission requires regular maintenance by lubrication and by adjusting the play of the parts so that the control corresponds to the target point.

[0008] Furthermore, the contact of the parts with each other of this type of transmission can cause significant wear rates in the context of intensive use such as pointing at very high speed at night to distant areas on the celestial vault.

[0009] The present invention aims to resolve all or part of the drawbacks mentioned above. Statement of the invention

[0010] To this end, the present invention relates to an angular positioning module for a positioning system of an optical bench, the positioning module angular including:

[0011] a fixed frame,

[0012] a rotating shaft mounted to rotate on the fixed frame relative to an angular positioning axis,

[0013] a rotary motor mounted on the fixed frame, the rotary motor including an output rod extending along a drive axis parallel to the angular positioning axis, the output rod being configured to move in rotation about the drive axis in either direction,

[0014] a transmission device being provided with a pulley mounted so as to rotate integrally on the output rod of the rotary motor, a wheel mounted so as to rotate integrally on the rotating shaft, and a cable wound on the one hand around the pulley and on the other hand around the wheel so that the pulley and the wheel are linked by two separate strands of the cable, the rotation of the pulley causing the winding of a first strand and the simultaneous unwinding of a second separate strand around the pulley and vice versa.

[0015] The fact that two separate strands of the cable connect the pulley to the wheel improves the reliability of the transmission. This simultaneous winding and unwinding of two separate strands allows transmission of movement from the pulley to the wheel in both directions of rotation.

[0016] The rotating shaft is therefore adapted to provide guidance in one direction of rotation and in the other, around the angular positioning axis of a part of the optical bench to aim at a point in the observed space.

[0017] Unlike a gear transmission, it is not necessary to regularly lubricate the cable transmission. This makes maintenance of this type of cable transmission easier.

[0018] The rotation of the output rod of the motor causes a first strand to be wound in one winding direction and the second strand to be unwound in the opposite direction on the wheel.

[0019] According to one aspect of the invention, the rotating shaft is arranged to be connected to a part of the movable optical bench for the alignment of an optical axis of the optical bench with a point in the targeted space.

[0020] One of the advantages of cable guidance is also that it allows the rotating shaft to make several turns in one direction and several turns in the other direction.

[0021] This can be advantageous when multiple positioning modules are used.

[0022] According to one aspect of the invention, the cable is capable of being greased for life during the manufacture of the angular positioning module, no other lubrication being required thereafter. necessary.

[0023] The use of a pulley and a wheel generates a large gear ratio, which allows high drive torques. The angular positioning module thus has the capacity to drive highly unbalanced optical systems (torque greater than 100 Nm).

[0024] According to one aspect of the invention, the cable has two ends, each end being mounted in a corresponding clamping device of the angular positioning module secured to the wheel.

[0025] This arrangement makes it easier to mount the cable on the wheel. Also, the cable can be tightened at each of its two ends. This facilitates maintenance when the cable becomes loose.

[0026] The cable thus held under tension by its two ends, the first strand and the second strand can be kept taut by tightening each end. This uniform tightening ensures good precision of the transmission and thus of the angular positioning of the rotating shaft.

[0027] By end is meant a terminal portion of the cable having a certain length.

[0028] According to one aspect of the invention, each clamping device is a tension coil capable of being connected to the corresponding end of the cable, the tension coil being received in a corresponding housing of the wheel.

[0029] This arrangement makes it possible to minimize the space taken up by the clamping devices.

[0030] According to one aspect of the invention, the wheel has an external surface of revolution around which the first strand of the cable is capable of being wrapped in a first direction of rotation and the second strand of the cable is capable of being wrapped in a second opposite direction of rotation, the external surface of revolution having a first access orifice to a first tension coil and a second access orifice to a second tension coil.

[0031] This arrangement allows the two ends of the cable to be inserted inside the wheel so that each is held by the corresponding tension coil.

[0032] The first strand and the second strand are wound in opposite directions relative to the angular positioning axis.

[0033] According to one aspect of the invention, each clamping device comprises an anti-return arrangement preventing slackening of the cable once clamped.

[0034] This arrangement improves the reliability of the angular positioning module because the cable cannot be slackened after being tensioned. The anti-return arrangement is configured to allow the cable to be tightened, i.e. the length of cable wound around the pulley and around the wheel to be reduced by pulling on the corresponding end.

[0035] According to one aspect of the invention, the pulley has an external tubular face extending around the drive axis and an internal channel extending parallel to the drive axis and opening at each end of the external tubular face, the cable being able to be inserted into the internal channel so that the first strand exits at a first end and the second strand at a second end, the first strand being wound in a first direction of rotation relative to the drive axis around the external tubular face and the second strand being wound in a second opposite direction of rotation around the external tubular face.

[0036] This arrangement allows the cable to be placed on the pulley and each strand to be wound in a specific direction of rotation around the pulley. These opposite directions of rotation of the strands allow simultaneous winding and unwinding during rotation of the pulley. This arrangement also ensures that the cable is locked in translation.

[0037] According to one aspect of the invention, each strand is wound helically around the pulley, each winding being spaced a first constant pitch from the adjacent winding.

[0038] Preferably, the helical winding is maintained by the tension of the cable, no guidance being necessary. Thus, the external surface of revolution and the external tubular face are flat. They do not have a rib or groove for guiding the cable.

[0039] According to one aspect of the invention, each strand is wound helically around the wheel, each winding being a second constant pitch apart from the adjacent winding.

[0040] Similarly, the helical winding is maintained by the tension of the cable, no guidance being necessary. The first strand winds in a first direction with the same pitch but in the opposite direction relative to the second strand.

[0041] According to one aspect of the invention, the fixed frame comprises a rolling system configured to maintain the rotating shaft along the angular positioning axis and to maintain a direction of extension of the rotating shaft coincident with the angular positioning axis.

[0042] This arrangement ensures good positioning of the rotating shaft while allowing rapid rotation around the angular positioning axis in one direction or the other.

[0043] According to one aspect of the invention, the bearing system comprises at least one conical bearing with a first part secured to the rotating shaft and a second part secured to the fixed frame.

[0044] This arrangement facilitates maintenance of the rotating shaft, the bearing system limiting friction. Furthermore, the bearing system is easily accessible for lubrication.

[0045] According to one aspect of the invention, the fixed frame comprises a top plate and a bottom plate extending transversely to the angular positioning axis, and holding columns securing the top plate and the bottom plate and extending parallel to the angular positioning axis.

[0046] This arrangement makes assembly easier. According to one aspect of the invention, a first part of a first conical bearing is secured to the upper plate and a first part of a second conical bearing is secured to the lower plate.

[0047] A second part of the first tapered bearing and a second part of the second tapered bearing are integral with the rotating shaft.

[0048] The positioning module is therefore both light and solid thanks to the conical bearings and the presence of columns.

[0049] According to one aspect of the invention, the angular positioning module comprises a spacer secured to the holding columns and the rotary motor. This arrangement makes it possible to hold the rotary motor in position without weighing down the fixed frame.

[0050] All components are made on traditional machining machine tools and do not require expensive or difficult to access tools. The components are from mechanical standards and can be easily and sustainably replaced.

[0051] The present invention also relates to a positioning system for an optical bench comprising two angular positioning modules as described above, the fixed frame of a first angular positioning module being fixed and the fixed frame of a second angular positioning module being rotationally integral with the rotating shaft of the first angular positioning module.

[0052] Such a positioning system allows easy pointing of a point in space by combining two angular positioning modules. According to one aspect of the invention, the positioning system comprises a counterweight capable of being fixed to the second angular positioning module.

[0053] Preferably, the rotating shaft of the second angular positioning module is capable of being mounted integral in rotation with a mobile element of the optical bench.

[0054] According to one aspect of the invention, the positioning system comprises a control device arranged to control the rotary motor of each angular positioning module, the control corresponding to a request for rotation according to an angle defined in one direction or the other relative to the angular positioning axis of the controlled rotating shaft.

[0055] The present invention also relates to an optical bench comprising a positioning system as described above.

[0056] The different aspects defined above which are not incompatible can be combined. Brief description of the figures

[0057] The invention will be better understood with the aid of the detailed description which is set out below with reference to the appended drawings.

[0058] [Fig-1] is a schematic view of an angular positioning module.

[0059] [Fig.2] is a perspective view of a wheel mounted on a rotating shaft and a pulley of the angular positioning module.

[0060] [Fig.3a] is a perspective view with a section of the wheel and the rotating shaft.

[0061] [Fig.3b] is a perspective view of a clamping device intended to be received in a corresponding wheel housing.

[0062] [Fig.4] is a perspective view of the pulley and cable before winding.

[0063] [Fig.5] is a schematic view of the wheel, pulley and cable.

[0064] [Fig.6] is a perspective view of a positioning system comprising two angular positioning modules and a counterweight. Description with reference to figures

[0065] In the detailed description which follows of the figures defined above, the same elements or the elements fulfilling identical functions may retain the same references so as to simplify the understanding of the invention.

[0066] As illustrated in Figures 1 to 6, a diagram details an angular positioning module 1 for a positioning system 3 of an optical bench.

[0067] The angular positioning module 1 comprises a fixed frame 5, a rotating shaft 7 mounted to move in rotation on the fixed frame 5 relative to an angular positioning axis 9.

[0068] The angular positioning module 1 also comprises a rotary motor 11 mounted on the fixed frame 5. The rotary motor 11 includes an output rod 13 extending along a drive axis 15 parallel to the angular positioning axis 9, the output rod 13 being configured to move in rotation around the drive axis 15 in one direction and in the other.

[0069] The angular positioning module 1 comprises a transmission device 17 provided with a pulley 19 mounted integral in rotation on the output rod 13 of the rotary motor 11, a wheel 21 mounted integral in rotation on the rotating shaft 7, and a cable 23 wound on the one hand around the pulley 19 and on the other hand around the wheel 21 so that the pulley 19 and the wheel 21 are linked by two separate strands of the cable 23.

[0070] The rotation of the pulley 19 causes the winding of a first strand 25 and the simultaneous unwinding of a second separate strand 27 around the pulley 19 and vice versa. The rotary motor 11 is able to rotate in both directions, the unwinding of the first strand 25 involving the winding of the second strand 27.

[0071] This simultaneous winding and unwinding of two separate strands allows transmission of movement from the pulley 19 to the wheel 21 in both directions of rotation.

[0072] The rotating shaft 7 is therefore adapted to provide guidance in one direction of rotation and in the other around the angular positioning axis 9 of a part of the optical bench which must be moved to aim at a point in the observed space.

[0073] The rotation also causes the first strand 25 to rotate in one direction of rotation and the second strand 27 to rotate in an opposite direction of rotation around the wheel.

[0074] The rotating shaft 7 is arranged to be connected to a part of the optical bench or a connecting element to the movable optical bench for the alignment of an optical axis of the optical bench with a point in the targeted space.

[0075] The cable 23 is capable of being greased for life during the manufacture of the angular positioning module 1, no further lubrication being necessary thereafter.

[0076] The use of a pulley 19 and a wheel 21 generates a large gear ratio, which allows high drive torques. The angular positioning module 1 thus has the capacity to drive highly unbalanced optical benches (torque greater than 100 Nm).

[0077] The cable 23 has two ends, each end being mounted in a corresponding clamping device 29 secured to the wheel 21.

[0078] The cable 23 thus held under tension by its two ends, the first strand 25 and the second strand 27 can be kept taut by tightening each end. This uniform tightening ensures good precision of the transmission and thus of the angular positioning of the rotating shaft 7.

[0079] By end is meant a terminal portion of the cable 23 having a certain length.

[0080] As illustrated in Figures 3a and 3b, each clamping device 29 is a tension coil capable of being connected to the corresponding end of the cable 23, the tension coil being received in a corresponding housing 31 of the wheel 21.

[0081] To fix the end of the cable 23, the clamping device 29 can be removed about ten centimeters from its housing 31.

[0082] The corresponding end of the cable 23 is then fixed by passing through the hole a, coming out through the hole b, then making a turn c around the tension coil to enter again through the hole b to come out through the hole a.

[0083] The first winding obtained by going around c is tightened by pulling on the cable and a pressure screw 32 of the tightening device is then tightened.

[0084] The end of the cable 23 emerging from the hole a can be cut and the clamping device 29 can be replaced in its housing 31.

[0085] The wheel 21 has an external surface of revolution 33 around which the first strand 25 of the cable 23 is capable of being surrounded in a first direction of rotation and the second strand 27 of the cable 23 is capable of being surrounded in a second opposite direction of rotation.

[0086] The external surface of revolution 33 has a first access orifice 35 to a first voltage coil and a second access orifice 37 to a second voltage coil.

[0087] The first strand 25 and the second strand 27 are wound in opposite directions relative to the angular positioning axis 9.

[0088] Each clamping device 29 comprises an anti-return arrangement preventing slackening of the cable 23 once clamped.

[0089] The anti-return arrangement is configured to allow the tightening of the cable 23, i.e. the reduction of the length of cable 23 wound around the pulley 19 and around the wheel 21 by pulling on the corresponding end.

[0090] The pulley 19 has an external tubular face 38 extending around the drive axis 15 and an internal channel 39 extending parallel to the drive axis 15 and opening at each end of the external tubular face 38.

[0091] The cable 23 is capable of being inserted into the internal channel 39 so that the first strand 25 exits at a first end and the second strand 27 at a second end.

[0092] The first strand 25 is wound in a first direction of rotation relative to the drive axis 15 around the external tubular face 38 and the second strand 27 being wound in a second opposite direction of rotation around the external tubular face 38.

[0093] These opposite directions of rotation of the strands allow simultaneous winding and unwinding during rotation of the pulley 19.

[0094] Each strand is wound helically around the pulley 19, each winding being a constant first pitch apart from the adjacent winding.

[0095] Each strand is wound helically around the wheel 21, each winding being a second constant pitch apart from the adjacent winding.

[0096] Similarly, the helical winding is maintained by the tension of the cable, no guidance being necessary. Thus, the external surface of revolution 33 and the external tubular face 38 are flat. They do not have a rib or groove for guiding the cable 23.

[0097] The fixed frame 5 comprises a bearing system 41 configured to hold the rotating shaft 7 along the angular positioning axis 9 and to maintain a direction of extension of the rotating shaft 7 coincident with the angular positioning axis 9.

[0098] The bearing system 41 comprises at least one conical bearing 43 with a first part secured to the rotating shaft 7 and a second part secured to the frame fixed 5.

[0099] The fixed frame 5 comprises a top plate 45 and a bottom plate extending transversely to the angular positioning axis, and holding columns 48 securing the top plate 45 and the bottom plate 47 and extending parallel to the angular positioning axis 9.

[0100] A first part of a first conical bearing is secured to the upper plate 45 and a first part of a second conical bearing is secured to the lower plate 47.

[0101] A second part of the first tapered bearing and a second part of the second tapered bearing are integral with the rotating shaft 7.

[0102] The angular positioning module 1 comprises a spacer 49 secured to the holding columns 48 and the rotary motor 11. This arrangement makes it possible to hold the rotary motor 11 in position without weighing down the fixed frame 5.

[0103] As illustrated in [Fig.6], the positioning system 3 for an optical bench comprises two angular positioning modules 1.

[0104] The fixed frame 5 of a first angular positioning module 1 is fixed and the fixed frame 5 of a second angular positioning module 1 is rotationally fixed to the rotating shaft 7 of the first angular positioning module 1.

[0105] The positioning system 3 comprises a counterweight 51 capable of being fixed to the second angular positioning module 1.

[0106] The rotating shaft 7 of the second angular positioning module 1 is capable of being mounted integral in rotation with a mobile element of the optical bench.

[0107] The positioning system 3 comprises a control device 53 arranged to control the rotary motor 11 of each angular positioning module 1.

[0108] The command corresponds to a request for rotation according to an angle defined in one direction or the other relative to the angular positioning axis 9 of the controlled rotating shaft 7.

[0109] An optical bench can thus comprise such a positioning system 3 to facilitate pointing while having good reliability.

[0110] The fact that two separate strands of the cable 23 connect the pulley 19 to the wheel 21 improves the reliability of the transmission. Unlike a gear transmission, it is not necessary to regularly grease the cable transmission 23. Maintenance of this type of cable transmission 23 is thus facilitated.

[0111] One of the advantages of the cable guide 23 is also to be able to allow the rotating shaft 7 to make several turns in one direction and several turns in the other direction.

[0112] As goes without saying, the invention is not limited to the single embodiment described above as an example; on the contrary, it encompasses all the variant embodiments thereof. lization.

Claims

Claims

1. Angular positioning module (1) for a positioning system (3) of an optical bench, the angular positioning module (1) comprising: - a fixed frame (5), - a rotating shaft (7) mounted so as to be able to rotate on the fixed frame (5) relative to an angular positioning axis (9), - a rotary motor (11) mounted on the fixed frame (5), the rotary motor (11) including an output rod (13) extending along a drive axis (15) parallel to the angular positioning axis (9), the output rod (13) being configured to move in rotation about the drive axis (15) in one direction and in the other, - a transmission device (17) being provided with a pulley (19) mounted so as to rotate integrally on the output rod (13) of the rotary motor (11), a wheel (21) mounted so as to rotate integrally on the rotary shaft (7),and a cable (23) wound on the one hand around the pulley (19) and on the other hand around the wheel (21) so that the pulley (19) and the wheel (21) are linked by two separate strands of the cable (23), the rotation of the pulley (19) causing the winding of a first strand (25) and the simultaneous unwinding of a second separate strand (27) around the pulley (19) and vice versa, characterized in that the cable (23) has two ends, each end being mounted in a corresponding clamping device (29) of the angular positioning module (1) secured to the wheel (21).,

2. Angular positioning module (1) according to claim 1, wherein each clamping device (29) is a tension coil adapted to be connected to the corresponding end of the cable (23), the tension coil being received in a corresponding housing (31) of the wheel (21).

3. Angular positioning module (1) according to claim 2, wherein the wheel (21) has an external surface of revolution (33) around which the first strand (25) of the cable (23) is able to be surrounded in a first direction of rotation and the second strand (27) of the cable (23) is able to be surrounded in a second direction of rotation opposite, the external surface of revolution (33) having a first access orifice (35) to the first tension coil and a second access orifice (37) to the second tension coil.

4. Angular positioning module (1) according to one of claims 1 to 3, wherein each clamping device (29) comprises a non-return arrangement preventing relaxation of the cable (23) once clamped.

5. Angular positioning module (1) according to one of claims 1 to 4, wherein the pulley (19) has an external tubular face (38) extending around the drive axis (15) and an internal channel (39) extending parallel to the drive axis (15) and opening at each end of the external tubular face (38), the cable (23) being able to be inserted into the internal channel (39) so that the first strand (25) exits at a first end and the second strand (27) at a second end, the first strand (25) being wound in a first direction of rotation relative to the drive axis (15) around the external tubular face (38) and the second strand (27) being wound in a second opposite direction of rotation around the external tubular face (38).

6. Angular positioning module (1) according to one of claims 1 to 5, in which each strand is wound helically around the pulley (19), each winding being distant by a first constant pitch from the contiguous winding.

7. An angular positioning module (1) according to claim 6, wherein each strand is wound helically around the wheel, each winding being spaced a second constant pitch from the adjacent winding.

8. Angular positioning module (1) according to one of claims 1 to 7, wherein the fixed frame (5) comprises a rolling system (41) configured to hold the rotating shaft (7) along the angular positioning axis (9) and to maintain a direction of extension of the rotating shaft (7) coincident with the angular positioning axis (9).

9. Angular positioning module (1) according to claim 8 wherein the bearing system (41) comprises at least one conical bearing (43) with a first part secured to the rotating shaft (7) and a second part secured to the fixed frame (5).

10. Angular positioning module (1) according to one of the claims 1 to 9, in which the fixed frame (5) comprises a high plate (45) and a low plate (47) extending transversely to the angular positioning axis (9), and, holding columns (48) securing the high plate (45) and the low plate (47) and extending parallel to the angular positioning axis (9).

11. Positioning system (3) for an optical bench comprising two angular positioning modules (1) according to one of claims 1 to 10, the fixed frame (5) of a first angular positioning module (1) being fixed and the fixed frame (5) of a second angular positioning module (1) being rotationally fixed to the rotating shaft (7) of the first angular positioning module (1).

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