A fully constrained mirror multi-point counterbalanced back support device

Abstract

The application discloses a fully-constrained mirror multi-point balanced back support device, which comprises three groups of support device assemblies arranged along a circumference, each group of support device assemblies comprises a group of axial support assemblies and a group of transverse support assemblies; the axial support assembly comprises a rotating shaft seat, a crossbeam, a rotating flexible joint, a tripod, an axial support flexible rod and an axial support disc; the transverse support assembly comprises a transverse support seat, a transverse pull rod and a transverse support disc; the three groups of support device assemblies form constraints on the translational freedom degrees of R direction, T direction and Z direction, the rotational freedom degrees around R direction, T direction and Z direction of the mirror. The application can not only ensure the ability of the mirror assembly to resist the vibration environment of the active stage, but also can adapt to the influence of the change of the in-orbit environmental temperature on the surface shape precision.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optical-mechanical structure of space remote sensor, and relates to a multi-point balanced back support device for a large mirror in a large-aperture space optical remote sensor. BACKGROUND

[0002] There is a widely used back support method for a ground-based large-aperture mirror, i.e., multi-point balanced support (Whiffle-tree support), which is usually combined with central support or circumferential support to achieve complete constraint of the mirror and ensure position stability of the mirror in various mechanical vibration environments. The mirror support device applied to a large-aperture space optical remote sensor is limited by mass, space of a carrier, layout of an optical system, etc., and may not be able to install central support or circumferential support, so that the mirror assembly is under-constrained, a large displacement and deformation are generated in a vibration environment in the active stage, the support device is failed, and the mission fails. SUMMARY

[0003] The present application aims to overcome the above-mentioned defects, and provides a multi-point balanced back support device for a completely constrained mirror, which solves the technical problem of under-constraint of the mirror assembly caused by the existing support method, and ensures the ability of the mirror assembly to resist the vibration environment in the active stage and the influence of the change of the on-orbit environmental temperature on the surface shape accuracy.

[0004] To achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0005] A multi-point balanced back support device for a completely constrained mirror, comprising three groups of support device assemblies arranged along a circumference, each group of support device assemblies comprising a group of axial support assemblies and a group of transverse support assemblies;

[0006] The axial support assembly comprises a rotating shaft seat, a cross beam, a rotating flexible joint, a triangular frame, an axial support flexible rod, and an axial support disc;

[0007] The middle part of the cross beam is supported on an external structure by the rotating shaft seat, and the rotating shaft seat is a flexible hinge structure providing a rotating degree of freedom around the R direction and a rotating degree of freedom around the T direction;

[0008] The two ends of the cross beam are supported on the external structure by the triangular frame, and the triangular frame is connected with the end part of the cross beam through the rotating flexible joint, and the rotating flexible joint is a flexible hinge structure providing a rotating degree of freedom around the R direction and a rotating degree of freedom around the T direction;

[0009] The axial support disc is installed above the three end parts of the triangular frame through the axial support flexible rod; the axial support disc is bonded with the back of the mirror, and the two ends of the axial support flexible rod are flexible hinge structures providing a translational degree of freedom along the R direction and a translational degree of freedom along the T direction;

[0010] The lateral support assembly comprises a lateral support, a lateral pull rod and a lateral support disc;

[0011] The lateral support is located at one side of the cross beam, and the lower end of the lateral support is fixed to the external structure. One end of the lateral pull rod is connected to the upper end of the lateral support, and the other end of the lateral pull rod is connected to the lateral support disc. The lateral support disc is bonded to the back of the mirror, and the lateral pull rod is used to constrain the translational freedom of the lateral support disc in the T direction;

[0012] The three sets of support device assemblies constrain the translational freedom of the mirror in the R direction, the translational freedom of the mirror in the T direction, the translational freedom of the mirror in the Z direction, the rotational freedom of the mirror around the R direction, the rotational freedom of the mirror around the T direction, and the rotational freedom of the mirror around the Z direction;

[0013] The R direction and the T direction are the radial direction and the tangential direction of the mirror respectively, and the Z direction is the direction of the rotation axis of the mirror. Here, the R direction is the line connecting the center of the mirror and the center of the specific component, and the T direction is the direction perpendicular to the R direction in the plane of the mirror. For example, in the flexible hinge structure for providing the rotational freedom of the mirror around the R direction and the rotational freedom of the mirror around the T direction, the R direction is the line connecting the center of the mirror and the center of the pivot seat.

[0014] Further, each lateral support assembly comprises two lateral supports, two lateral pull rods and two lateral support discs;

[0015] The two lateral supports are located at the same side of the cross beam;

[0016] The two lateral support discs are located above the center of the tripod respectively.

[0017] Further, one end of the lateral pull rod is connected to the upper end of the lateral support through a radial ball bearing.

[0018] Further, the cross beams in the two adjacent sets of axial support assemblies are arranged at an angle of 60°;

[0019] The two lateral supports in each lateral support assembly are located at the outer side of the cross beam.

[0020] Further, the pivot seat is a straight circular flexible hinge structure, and the upper end and the lower end of the pivot seat are fixedly connected with the external structure and the cross beam respectively.

[0021] Further, the rotational flexible joint adopts two layers of orthogonal straight circular flexible hinge structures.

[0022] The upper end and the lower end of the rotational flexible joint are fixedly connected with the end of the cross beam and the center of the tripod respectively.

[0023] Further, the two ends of the axial support flexible rod adopt straight circular flexible hinge structures.

[0024] The straight circular flexible hinge structure is used for moving along the R direction and the T direction when the axial support flexible rod is forced at both ends, and the axial support flexible rod is constrained from moving along the Z axis.

[0025] Further, the axial support flexible rod is perpendicular to the surface of the external structure in the state of no force.

[0026] Further, the cross beam is a trapezoidal structure with the upper end length being greater than the lower end length.

[0027] Further, the cross beam is provided with a plurality of lightening grooves.

[0028] Compared with the prior art, the present application has at least one of the following beneficial effects:

[0029] (1) The present application creatively proposes a completely constrained mirror multi-point balanced back support device, which has a statically determinate support effect meeting the kinematic principle, can guarantee the ability of the mirror assembly to resist the vibration environment of the active stage, and can adapt to the influence of the change of the on-orbit environment temperature on the surface shape accuracy.

[0030] (2) All support structures of the present application are located at the back of the mirror and are constrained within the diameter of the mirror. While guaranteeing the transverse mechanical properties of the mirror assembly, the mirror peripheral support assembly is eliminated, so that the radial size of the mirror assembly does not exceed the diameter of the mirror, which is beneficial to reducing the overall size of the space remote sensor. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a schematic view of the completely constrained mirror multi-point balanced back support device of the present application;

[0032] Figure 2 It is a support point distribution diagram of the present application;

[0033] Figure 3 It is an application example diagram of the present application;

[0034] Figure 4 It is a structure diagram of the axial support flexible rod of the present application;

[0035] Figure 5 It is a schematic view of the rotating flexible joint of the present application;

[0036] Figure 6 It is a schematic view of the rotating shaft seat of the present application;

[0037] In the figure, 1 is a rotating shaft seat, 2 is a cross beam, 3 is a rotating flexible joint, 4 is a triangular frame, 5 is an axial support flexible rod, 6 is an axial support disc, 7 is a transverse support, 8 is a transverse pull rod, and 9 is a transverse support disc. DETAILED DESCRIPTION

[0038] The features and advantages of the present application will become more apparent from the detailed description set forth below when taken in conjunction with the drawings.

[0039] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Unless specifically stated otherwise, the drawings are not drawn to scale and are merely intended to conceptually illustrate aspects of the embodiments.

[0040] The present application provides a fully constrained mirror multi-point balanced back support device, which realizes full constraint of a large aperture mirror, saves mass and space, and realizes static support of the mirror.

[0041] The present application is composed of three sets of same axial support assemblies and transverse support assemblies arranged in a circumferential array, the axial support assembly comprises a rotating shaft seat, a crossbeam, a rotating flexible joint, a tripod, an axial support flexible rod and an axial support disc, and the transverse support assembly comprises a transverse support seat, a transverse pull rod and a transverse support disc.

[0042] The technical principle of realizing full constraint of the mirror assembly of the present application is as follows:

[0043] The 6 degrees of freedom of the reflector can be expressed as 3 moving (translational) degrees of freedom along the radius axis R, the tangential axis T and the vertical axis Z, and 3 rotating degrees of freedom around R, T and Z. According to the kinematic principle, each set of axial support assembly first expands one 1-level axial support point formed by the shaft seat and the external structure into two 2-level axial support points through the cross beam, i.e. the support of the two tripods on the two ends of the cross beam; then expands the 2-level axial support point on the cross beam into 3 3-level axial support points through the rotating flexible joint, i.e. the support of the three axial support discs on the back of the reflector, and finally forms 3*2*3=18 axial support points, with the axial support disc at the end of the axial support point being bonded to the reflector, the axial support disc serving as the transition between the axial support flexible rod and the reflector, expanding the stress area of the support point and reducing the stress of the reflector. When expanding each level of axial support point, the freedom is released through the flexible hinge structure, so that each set of axial support assembly provides a Z-direction constraint. Under the action of the 3 sets of axial support assemblies, the translational movement of the reflector along the Z axis and the rotation of the reflector around the R axis and the T axis are constrained (the translational movement of the three sets in the Z direction is combined to form the constraint of the rotation of R and T), but the rotation of the reflector around the Z axis and the translational movement of the reflector along the R axis and the T axis are in an under-constrained state. On this basis, each set of transverse support assembly provides a T-direction translational constraint, and under the action of the 3 sets of transverse support assemblies, the rotation of the reflector around the Z axis and the translational movement of the reflector along the R axis and the T axis are constrained. Thus, the reflector multi-point balanced back support device provided by the present application realizes the complete constraint of the 6 degrees of freedom of the reflector.

[0044] Embodiment:

[0045] The present embodiment provides a completely constrained reflector multi-point balanced back support device, which is formed by 3 sets of identical axial support assemblies and transverse support assemblies arranged in a circumferential array. The axial support assemblies and the transverse support assemblies are both located on the back of the reflector.

[0046] As Figure 1 , the axial support assembly includes a shaft seat 1, a cross beam 2, a rotating flexible joint 3, a tripod 4, an axial support flexible rod 5 and an axial support disc 6. The shaft seat 1 is used for connecting the axial support assembly and the external structure. Specifically, as Figure 6 , the shaft seat 1 adopts a straight circular flexible hinge structure, so that the cross beam 2 can rotate by a small angle around the shaft seat 1, i.e. a small angle of rotation around the R direction.

[0047] The rotating flexible joint 3 connects the cross beam 2 and the tripod 4 through a screw, and specifically, as Figure 5 , the rotating flexible joint 3 adopts a two-layer orthogonal straight circular flexible hinge structure, so that the tripod 4 can rotate by a small angle around the R axis and the T axis of the rotating flexible joint 3.

[0048] The axial support disc 6 is bonded with the mirror, serving as a transition between the axial support flexible rod 5 and the mirror, expanding the force area of the support point and reducing the stress of the mirror.

[0049] Specifically, as shown in Figure 4 , the axial support flexible rod 5 adopts a straight circular flexible hinge structure at both ends, so that when the axial support flexible rod 5 at both ends is subjected to force, it can slightly move along the R-axis and T-axis direction, and only restrict the movement of the axial support flexible rod 5 along the Z-axis, thereby forming a three-level axial support point, as shown in Figure 2 .

[0050] Specifically, when the flexible hinge of the rotating flexible joint 3 is subjected to force, it will slightly rotate around the R-axis and T-axis direction, which can be regarded as the fulcrum of a lever, and the tripod 4 is regarded as a lever, and the three axial support flexible rods 5 connected thereto can slightly rotate around the rotating flexible joint 3 and restrict the translation of the rotating flexible joint 3, thereby forming a two-level axial support point. Similarly, the rotating shaft seat 1 can also be regarded as a fulcrum of a lever, and the cross beam 2 is regarded as a lever, and the two two-level axial support points connected at both ends thereof can rotate around the rotating shaft seat and restrict the translation of the rotating shaft seat 1, thereby forming a one-level axial support point.

[0051] Specifically, as shown in Figure 3 , under the action of the three groups of circumferentially arrayed axial support assemblies, the movement of the mirror along the Z-axis and the rotation of the mirror around the R-axis and T-axis are restricted.

[0052] The lateral support assembly includes a lateral support 7, a lateral pull rod 8 and a lateral support disc 9.

[0053] The lateral support disc 9 is bonded with the mirror, and the lateral support 7 is fixed to the external structure, and the lateral pull rod 8 is used to connect the lateral support 7 and the lateral support disc 9. The lateral support disc 9 can be at any position, and the lateral pull rod 8 needs to have a large angle with the mirror in the radial direction, that is, the optimal scheme is that the center line of the center of the lateral support disc 9 and the center of the mirror is perpendicular to the lateral pull rod 8.

[0054] Specifically, the lateral pull rod 8 and the lateral support disc 9 are connected through a radial ball bearing to provide a translational constraint in the R direction. Under the action of the three sets of lateral support assemblies, the rotation of the mirror around the Z-axis and the movement of the mirror along the T-axis are restricted.

[0055] The one-level axial support point, the two-level axial support point, the three-level axial support point and the lateral support point in the same group of axial support assemblies and lateral support assemblies restrict the six degrees of freedom of the mirror as shown in Table 1.

[0056] Table 1 Restriction of support points to the degrees of freedom of the mirror

[0057] Support point R-axis translation T-axis translation Z-axis translation R-axis rotation T-axis rotation Z-axis rotation 1st level axial support point Constrained Constrained Constrained Unconstrained Constrained Constrained 2nd level axial support point Constrained Constrained Constrained Unconstrained Unconstrained Constrained 3rd level axial support point Unconstrained Unconstrained Constrained Unconstrained Unconstrained Constrained Lateral support point Unconstrained Constrained Unconstrained Constrained Constrained Unconstrained

[0058] According to Table 1, three sets of axial support assemblies and transverse support assemblies are arranged at 120° around the center of the mirror to realize the constraint of the six degrees of freedom of the mirror.

[0059] In conclusion, the present application has the statically determinate support effect of satisfying the kinematic principle, which guarantees the ability of the mirror assembly to resist the vibration environment and the ability to adapt to the influence of the change of the in-orbit environmental temperature on the surface shape precision. The support structure located at the back of the mirror is used to realize the support device of the complete constraint of the degrees of freedom of the mirror assembly, thereby reducing the circumferential dimension of the mirror assembly.

[0060] The above detailed description of the present application is combined with the specific implementation and the exemplary examples, but these descriptions cannot be understood as the limitation of the present application. Those skilled in the art understand that the technical solutions and the implementation of the present application can be variously replaced, modified or improved without deviating from the spirit and scope of the present application, and these all fall within the scope of the present application. The protection scope of the present application is subject to the appended claims.

[0061] The contents not described in detail in the specification of the present application are the known technology of those skilled in the art.

Claims

1. A fully constrained mirror multi-point counterbalanced back support device, characterized by, The support device assembly includes three groups of circumferentially arranged support device assemblies, each group of support device assemblies including a group of axial support assemblies and a group of transverse support assemblies; The axial support assembly includes a rotating shaft seat (1), a crossbeam (2), a rotating flexible joint (3), a tripod (4), an axial support flexible rod (5), and an axial support disc (6); The middle part of the crossbeam (2) is supported on the external structure by the rotating shaft seat (1), and the rotating shaft seat (1) is a flexible hinge structure providing a rotating freedom degree around the R direction and a rotating freedom degree around the T direction; The two ends of the crossbeam (2) are supported on the external structure by the tripod (4), and the tripod (4) is connected to the end of the crossbeam (2) through the rotating flexible joint (3), and the rotating flexible joint (3) is a flexible hinge structure providing a rotating freedom degree around the R direction and a rotating freedom degree around the T direction; The axial support disc (6) is installed above the three ends of the tripod (4) through the axial support flexible rod (5), the axial support disc (6) is bonded to the back of the mirror, and the two ends of the axial support flexible rod (5) are flexible hinge structures providing a translational freedom degree along the R direction and a translational freedom degree along the T direction. The transverse support assembly includes a transverse support seat (7), a transverse pull rod (8), and a transverse support disc (9); The transverse support seat (7) is located on one side of the crossbeam (2), the lower end of the transverse support seat (7) is fixed on the external structure, one end of the transverse pull rod (8) is connected to the upper end of the transverse support seat (7), the other end of the transverse pull rod (8) is connected to the transverse support disc (9), the transverse support disc (9) is bonded to the back of the mirror, and the transverse pull rod (8) is used to constrain the translational freedom degree of the transverse support disc (9) along the T direction. The three groups of support device assemblies constrain the mirror to have a translational freedom degree along the R direction, a translational freedom degree along the T direction, a translational freedom degree along the Z direction, a rotating freedom degree around the R direction, a rotating freedom degree around the T direction, and a rotating freedom degree around the Z direction. The R direction and the T direction are the radial direction and the tangential direction of the mirror respectively, and the Z direction is the direction of the rotation axis of the mirror.

2. A fully constrained mirror multi-point counterbalanced back support device according to claim 1, wherein, Each group of transverse support assemblies includes two transverse support seats (7), two transverse pull rods (8), and two transverse support discs (9). The two transverse support seats (7) are located on the same side of the crossbeam (2). The two transverse support discs (9) are located above the center of the tripod (4) respectively.

3. A fully constrained mirror multi-point counterbalanced back support device according to claim 1, wherein, One end of the transverse pull rod (8) is connected to the upper end of the transverse support seat (7) through a radial ball bearing.

4. A fully constrained mirror multi-point counterbalanced back support device according to claim 2, wherein, The crossbeams (2) in the two adjacent groups of axial support assemblies are arranged at an angle of 60°. The two transverse support seats (7) in each group of transverse support assemblies are located on the outside of the crossbeam (2).

5. A fully constrained mirror multi-point counterbalanced back support device according to claim 1, wherein, The rotating shaft seat (1) is a straight circular flexible hinge structure, and the upper end and the lower end of the rotating shaft seat (1) are fixedly connected with the external structure and the crossbeam (2) respectively.

6. A fully constrained mirror multi-point counterbalanced back support device according to claim 1, wherein, The rotating flexible joint (3) is a two-layer orthogonal straight circular flexible hinge structure. The upper end and the lower end of the rotating flexible joint (3) are fixedly connected with the end of the crossbeam (2) and the center of the tripod (4) respectively.

7. A fully constrained mirror multi-point counterbalanced back support device according to claim 1, wherein, The two ends of the axial support flexible rod (5) are straight circular flexible hinge structures. The straight circular flexible hinge structure is used to make the two ends of the axial support flexible rod (5) move along the R direction and the T direction when subjected to force, and to constrain the axial support flexible rod (5) from moving along the Z axis.

8. A fully constrained mirror multi-point counterbalanced back support device according to claim 1, wherein, The axial support flexible rod (5) is perpendicular to the external structure surface in the non-force state.

9. A fully constrained mirror multi-point counterbalanced back support device according to claim 1, wherein, The crossbeam (2) is in trapezoidal structure with the upper end length greater than the lower end length.

10. A fully constrained mirror multi-point counterbalanced back support device according to claim 1, wherein, The crossbeam (2) and the tripod (4) are provided with a plurality of lightening grooves.

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