Optical rotary transmitter

Abstract

The invention describes an optical rotary transmitter with at least two housing parts, which are mounted so as to be rotatable relative to one another about an axis of rotation. An interior space is enclosed together with the at least two housing parts to be fluid impermeable manner by a membrane which completely encloses the interior space along one portion along the axis of rotation in a circumferential direction about the axis of rotation. The membrane is arranged so that at least portions of the surface of the membrane facing away from the interior space are accessible.

Claims

1. An optical rotary transmitter comprising: at least two housing parts, which are mounted relative to one another about a common axis of rotation and which surround an interior space to be fluid-impermeable at least in regions, and at least two optical waveguides which each protrude to be fluid-impermeable through the housing parts and each end in an interior space with an optical collimator on a respective end face so that the optical collimators on the ends of the two optical waveguides delimit both sides of an intermediate gap which is orientated along the axis of rotation; the interior space is enclosed with the at least two housing parts to be fluid-impermeable by a membrane, completely enclosing the interior space along at least one portion along the axis of rotation in a circumferential direction about the axis of rotation; and the membrane includes at least portions of the surface of the membrane facing away from the interior space which are accessible.

2. An optical rotary transmitter according to claim 1, wherein: the interior space is filled with a fluid which is transparent in an optical or near infrared wavelength spectrum.

3. An optical rotary transmitter according to claim 2, wherein: the fluid is one of the following fluids: aqueous solution, water, oil, hydraulic fluid, silicone oil.

4. An optical rotary transmitter according to claim 2, wherein: the membrane is an elastomer, is tubular and arranged on one of the at least two housing parts and forms a connection that seals the interior space by a pressing force preloaded by a form-locking connector.

5. An optical rotary transmitter according to claim 3, wherein: the membrane is an elastomer, is tubular and arranged on one of the at least two housing parts and forms a connection that seals the interior space by a pressing force preloaded by a form-locking connector.

6. An optical rotary transmitter according to claim 2, wherein: the membrane is connected to one of the at least two housing parts via at least one film hinge.

7. An optical rotary transmitter according to claim 3, wherein: the membrane is connected to one of the at least two housing parts via at least one film hinge.

8. An optical rotary transmitter according to claim 4, wherein: the membrane is connected to one of the at least two housing parts via at least one film hinge.

9. An optical rotary transmitter according to claim 2, wherein: the membrane has a maximum radial distance from the axis of rotation which is less than a maximum radial distance between the at least two housing parts and the axis of rotation, and at least a portion of one of the housing parts protrudes beyond at least a partial area of the membrane in the axial extension of the membrane radially outside towards the membrane.

10. An optical rotary transmitter according to claim 3, wherein: the membrane has a maximum radial distance from the axis of rotation which is less than a maximum radial distance between the at least two housing parts and the axis of rotation, and at least a portion of one of the housing parts protrudes beyond at least a partial area of the membrane in an axial extension of the membrane radially outside toward the membrane.

11. An optical rotary transmitter according to claim 4, wherein: the membrane has a maximum radial distance from the axis of rotation which is less than a maximum radial distance between the at least two housing parts and the axis of rotation, and at least a portion of one of the housing parts protrudes beyond at least a partial area of the membrane in an axial extension of the membrane radially outside toward the membrane.

12. An optical rotary transmitter according to claim 6, wherein: the membrane has a maximum radial distance from the axis of rotation which is less than a maximum radial distance between the at least two housing parts and the axis of rotation, and at least a portion of one of the housing parts protrudes beyond at least a partial area of the membrane in an axial extension of the membrane radially outside toward the membrane.

13. An optical rotary transmitter according to claim 2, wherein: one of the housing parts are immobile relative to other of the housing parts and at least portions of one of the housing parts are surrounded radially by another of the housing parts, and the membrane is attached to one of the housing parts to be fluid-impermeable.

14. An optical rotary transmitter according to claim 2, wherein: the optical collimators are connected to the waveguides and each collimator end face, delimits one side of an intermediate gap with an end face normal, and the optical collimators are arranged in such manner that end face normals thereof intersect each other at an angle α which is not equal to 0°.

15. An optical rotary transmitter according to claim 14, wherein: at least one of the optical collimators is disposed with the end face normal orientated at an angle to the axis of rotation.

16. An optical rotary transmitter according to claim 2, wherein: at least one of the optical collimators is a graded index lens.

17. An optical rotary transmitter according to claim 2, wherein: the optical collimators are each attached to the end faces of the waveguides fixedly to be resistant to pressure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following section, the invention will be described for exemplary purposes using exemplary embodiments thereof and with reference to the drawings, without general limitation of the invention. In the drawing:

(2) FIGS. 1a, b shows an external view of two optical rotating couplings; and

(3) FIG. 2 is a longitudinal cross section through an optical rotating coupling designed according to the invention.

WAYS TO IMPLEMENT THE INVENTION, COMMERCIAL APPLICABILITY

(4) FIG. 1a represents a perspective external view of an optical rotary transmitter 1 constructed according to the invention with one housing part 2 embodied as a stator and one housing part 3 embodied as a rotor, which is mounted so as to be rotatable relative to an axis of rotation D that passes through both housing parts 2, 3. One waveguide 4, 5, along which optical signals are transmitted by the optical rotary transmitter 1, runs into each of the two housing parts 2, 3.

(5) The housing part 2, which serves as the stator is furnished with window-like recesses 6, to which a flexible membrane 7 is attached radially inwardly and which radially completely surrounds the axis of rotation D and is connected in fluid-impermeable manner axially to both sides of the housing part 2. Preferably the connection is in the form of a force preloaded form-locking connector. The housing parts 2 and 3 together with the membrane 7 attached to the housing part 2 close off an interior space I in fluid-impermeable manner. See the longitudinal cross section view of FIG. 2, inside which the ends of both waveguides 4, 5 are mounted adjacent to each other for purposes of optical signal transmission.

(6) The large opening width of the window-like recesses 6 enables the flexible membrane 7 constructed in the form of a hollow cylindrical tubular section to be accessed without obstruction from the immediate surroundings of the optical rotary transmitter 1, so that the ambient pressure conditions are able to act on the entire outer shell surface of the flexible membrane 5. This design characteristic enables the optical rotary transmitter to be used under water, even at extreme depths and in conditions of dynamically changing ambient pressures that occur with mobile submarine objects, for example during deployment of underwater robots as a result of variable diving depths.

(7) FIG. 1b shows an alternative construction variant for producing an optical rotary transmitter 1 which is designed for submarine use and provides one stationary housing part 2 and one housing part 3 which rotates relative thereto. In the case of FIG. 1b as well, a tubular membrane 7, which completely surrounds the axis of rotation D in the circumferential direction, is connected to the housing part 2 in fluid-impermeable manner for the purpose of equalising the pressure at the stationary housing part 2. Housing part 2 is mounted immovably and is furnished with circular window openings 6 arranged evenly in the circumferential direction about the membrane 7, with the result that membrane 7 is completely surrounded fully accessible to the surrounding medium in the circumferential direction about the axis of rotation D. That is in the case of underwater deployment it is surrounded uniformly by water. Unlike the optical rotary transmitter 1 illustrated in FIG. 1a, which only couples a pair of waveguides 4, 5 to each other, which are arranged along the axis of rotation D, the optical rotary transmitter illustrated in FIG. 1b enables optical coupling between four individual optical waveguide pairs, 5.sup.I/4.sup.I, 5.sup.II/4.sup.II, 5.sup.III/4.sup.III, 5.sup.IV/4.sup.IV.

(8) FIG. 2 shows a schematic longitudinal cross section through an optical rotary transmitter 1 designed according to the invention for the optical coupling of two waveguides 4, 5 which are mounted to be rotatable relative to one another. The waveguide 4 passes through a fluid-impermeable fiber seal 8 and runs into the rotatably mounted housing part 3, and has an optical collimator device 9 on its end face, which system is connected to the waveguide 4 in a fixed manner which is resistant to pressure, for example by a welded connection.

(9) In the same way, the waveguide 5 passes through a fluid-impermeable fiber seal 8′ and terminates in the interior space of the immovably mounted housing part 2. The end of the housing part also has an optical collimator device 10 attached fixedly and is resistant to pressure. The two optical collimator devices 9, 10 delimit an intermediate gap 11 with their collimator end faces 9′, 10′, which gap assures a frictionless or low-friction bearing of the two opposing collimator end faces 9′, 10′, which are rotatable relative to each other.

(10) Both waveguides 4, 5 together with their optical collimator devices protrude into an interior space I, which is surrounded in a fluid-impermeable manner by both housing parts 2, 3 and by an elastically deformable membrane 7 which is connected in fluid-impermeable manner to the immovably mounted housing part 2. The elastic membrane 7 is manufactured from an elastomer material in the form of a tubular section and encloses the interior space I completely along an axial section a about the axis of rotation D. This ensures that the interior space I is sealed off from the surrounding medium in fluid-impermeable manner. The interior space I is also filled with a non-compressible fluid, preferably water, an aqueous solution, oil, particularly hydraulic oil or silicone oil, wherein the fluid is chosen to be transparent for light wavelengths preferably from the optical or infrared spectral range, which corresponds to the light that is to be transmitted via the waveguides 4, 5.

(11) In order to fill the interior space I with the fluid, at least two filling apertures 12, 13 which can be closed off in fluid-impermeable manner are created in the two housing parts 2, 3. In order to assure fluid sealing of the two housing parts 2, 3 which are mounted rotatably relative to one another, in the embodiment shown an immobile rotary seal 14 is used, having a sealing O-ring and a raceway on the outer sides of a housing component of the rotatably mounted housing part 3. In addition, a pivot bearing 15 ensures substantially lossless relative rotatability of the two housing parts 2, 3.

(12) A force preloaded form-locking connector conformed between the membrane 7 and the stationary housing part 2, which extends completely about the axis of rotation in circular and/or annular fashion on the two axially opposite ends of the tubular membrane 7 is used for fluid-impermeable sealing of the interior space I in the region of the membrane 7, which has the form of a tubular section of an elastomer material. Based on the shape or material chosen for the membrane 7, it is elastically deformable radially to the axis of rotation D, so that the ambient pressure prevailing in the environment surrounding the optical rotary transmitter bears evenly on the entire surface of the cylindrical outer shell surface of the membrane 7. For this purpose, window-like recesses 6 are created in the stationary housing part, see also FIG. 1a. In order to protect the membrane from external mechanical influences, the membrane 7 is arranged radial inwardly with respect to the radially outer surface of the stationary housing part 2.

(13) The housing parts 2, 3 are manufactured from mechanically robust, substantially chemically inert material, preferably stainless steel, and form a component which is resilient to external mechanical influences. As an alternative to the creation of the membrane 7 in the form of a tubular section manufactured from an elastomer material, it is also conceivable to construct the membrane 7 integrally with the housing part that is mounted immovable, that is from the same material as the housing part. For this purpose, generative manufacturing processes may be considered. To provide an elastic bearing for a membrane 7 which is manufactured integrally with the housing part 2 in this way, the membrane is preferably connected to the housing part via an elastic flexure bearing.

(14) The other components shown in FIG. 2 serve to minimize the friction as far as possible in the bearing of the two housing parts 2, 3 which are mounted rotatably relative to each other and are not central to the present invention.

(15) In order to reduce or entirely avoid interfering back reflection losses during the transmission of optical signals between the two collimator end faces, the optical collimator devices 9, 10 are preferably arranged relative to one another in such manner that their end face normals associated with the respective collimator end faces form an angle α≠0, i.e. they are not orientated plane-parallel to each other. A particularly advantageous arrangement of the at least two optical collimator devices constitutes an arrangement in which the surface normals of the two collimator end faces are each orientated at an angle to the axis of rotation D.

LIST OF REFERENCE SIGNS

(16) 1 Optical rotary transmitter 2 Fixedly mounted housing 3 Rotatably mounted housing 4, 5 Waveguides 4.sup.I, 4.sup.II, 4.sup.III, 4.sup.IV Waveguides 5.sup.I, 5.sup.II, 5.sup.III, 5.sup.IV Waveguides 6 Window recess 7 Membrane 7′, 7″ Axial ends of the membrane 8, 8′ Fluid-impermeable fiber seal 9, 10 Optical collimator device 9′, 10′ Collimator end face 11 Intermediate gap 12, 13 Filling mechanism 14 Rotary seal 15 Pivot bearing D Axis of rotation a Axial portion I Interior space