JP7118024B2 - Reducer and structure - Google Patents

Description

The present invention relates to a reduction gear that reduces input from an actuator and a structure that includes the reduction gear.

2. Description of the Related Art In a reflecting mirror support mechanism for an optical telescope mounted on an artificial satellite or the like, a 6-axis (3-axis shift, 3-axis tilt) support unit is used as described in Patent Document 1, for example.

JP 2014-151744 A

A reflecting mirror such as an optical telescope mounted on an artificial satellite or the like is configured by combining a plurality of segmented mirrors (segment mirrors). In such a reflecting mirror composed of split mirrors, it is necessary to adjust so that the step between adjacent split mirrors is about 1/10 of the wavelength (about 10 nanometers).
However, in the configuration described in Patent Document 1, there is no mechanism for finely adjusting the level difference between the split mirrors. Therefore, in the configuration described in Patent Document 1, there is a problem that high mirror surface accuracy cannot be obtained in the reflecting mirror using the segmented mirror.

One of the main objects of the present invention is to solve such problems. More specifically, the main object of the present invention is to obtain a high degree of mirror surface precision in a reflecting mirror using segmented mirrors.

A reduction gear according to the present invention includes:
Used in a reflecting mirror support mechanism that supports a reflecting mirror by a segmented mirror,
a lever that decelerates the input from the actuator to 1/n (n is a number greater than 1) and outputs a magnitude of 1/n of the input from the actuator;
a toggle mechanism that decelerates the input from the lever to 1/m (m is a number greater than 1) and outputs a magnitude of 1/m of the input from the lever.

In the present invention, the input from the actuator can be decelerated to 1/(n×m). Therefore, according to the present invention, it is possible to obtain a high degree of mirror surface accuracy in the reflecting mirror using the segmented mirror.

4A and 4B are diagrams showing an example of a reflector support mechanism according to the first embodiment; FIG. 4A and 4B are diagrams showing examples of a support structure, a reduction gear, and an actuator according to the first embodiment; FIG. 4A and 4B are diagrams showing examples of a support structure, a reduction gear, and an actuator according to the first embodiment; FIG. FIG. 4 shows an example of a lever and toggle mechanism according to the first embodiment; 4A and 4B are diagrams showing examples of a toggle angle θ according to the first embodiment; FIG. 4A and 4B are diagrams showing an example of a reflecting mirror according to the first embodiment; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the following description and drawings of the embodiments, the same reference numerals denote the same or corresponding parts.

Embodiment 1.
FIG. 1 shows an example of a reflector structure 7000 according to this embodiment. A reflecting mirror structure 7000 includes a reflecting mirror 1000 and a reflecting mirror support mechanism 700 .
A reflecting mirror 1000 is a reflecting mirror in which a plurality of segmented mirrors 100 are combined. Although FIG. 1 does not depict a plurality of segmented mirrors 100 combined for reasons of drawing, the reflecting mirror 1000 is a reflecting mirror made up of segmented mirrors.
A reflecting mirror support mechanism 700 is mounted on a spacecraft such as an artificial satellite, and supports a reflecting mirror 1000 such as an optical telescope.
The reflector support mechanism 700 is composed of a plurality of support units 200 and a plurality of structures 600 . The structure 600 individually supports each segmented mirror 100 that constitutes the reflecting mirror 1000 . The structures 600 are supported by the support units 200 respectively. The structure 600 has a dressing table 800 .

The support unit 200 is a support leg with a hexapod parallel mechanism. The support unit 200 is composed of nine rods. Three of the nine rods are combined to form a fixed truss 620 (support base) that forms a triangular unit truss. The rods that make up the fixed truss 620 are fixed in length. Two adjacent rods of the rods constituting the fixed truss 620 are connected to each other to form three nodes. The other six rods of the nine rods are connected to the nodes of the fixed truss 620 and combined to form the adjustment truss 650 . To each node of the fixed truss 620, the lower ends of the two rods of the adjusting truss 650 are connected in a V-shape to form a supporting structure for the bipod.
The upper ends of each of the two rods forming the adjustment truss 650 are coupled to the three nodes of the mirror stand 800 forming a triangular unit truss. The length of each of the six rods forming the adjustment truss 650 can be adjusted. By extending and contracting the six rods, it is possible to adjust and control deformation amounts (parameters of six degrees of freedom) of six axes (three shift axes and three tilt axes) that determine the position and attitude of the mirror stand 800 . The support unit 200 supports the mirror stand 800 of the structure 600 that supports the segmented mirror 100 and forms a truss structure for a coarse adjustment mechanism for roughly adjusting the position and orientation of the segmented mirror 100 .

A structure 600 is composed of a support structure 300 , a mirror stand 800 , a reduction gear 400 and an actuator 500 . The support structures 300 are fixed to the back sides of the mirror surfaces of the split mirror 100 to support the split mirror 100 .
The support structure 300 , mirror stand 800 , deceleration device 400 and actuator 500 constitute a fine adjustment mechanism that finely adjusts the position and orientation of the segmented mirror 100 .
Mirror base 800 combines three rods in a triangular shape to form a unit truss with a fixed length for each rod and supports the fine adjustment mechanism.

The reflector 1000 is configured like the reflector 1000a or the reflector 1000b shown in FIG.
As shown in FIGS. 6A and 6B, the large reflecting mirror 1000a or 1000b is formed as if it were a single mirror by combining a plurality of split mirrors 100a or 100b. be. A circular or polygonal hole is formed in the central portion of the reflecting mirror 1000b.
Each segmented mirror 100a is arranged in contact with or adjacent to the adjacent segmented mirror 100a, so that a plurality of segmented mirrors 100a are laid out without gaps to form one large reflecting mirror 1000a. The segmented mirrors 100a can be arranged in a hexagonal shape, for example, so that there is no space between them. The reflecting mirror 1000a can form and maintain a mirror surface shape with desired surface precision by adjusting the positions and attitudes of the plurality of segmented mirrors 100a with high precision.
In addition, each of the split mirrors 100b is arranged in contact with or in close proximity to the adjacent split mirror 100b, so that the plurality of split mirrors 100b are spread without gaps except for the central portion of the reflecting mirror 1000b, thereby reflecting the light. Configure mirror 1000b. The segmented mirror 100a, for example, has a hexagonal shape, so that it can be spread around the circular or polygonal hole in the reflecting mirror 1000b without gaps. The reflecting mirror 1000b can form and maintain a mirror surface shape with desired surface accuracy by adjusting the positions and attitudes of the plurality of split mirrors 100b with high accuracy.
The fixed truss 620 supporting the segmented mirror 100a and the structure 600 via the support unit 200 is connected to the fixed truss 620 supporting the other adjacent segmented mirror 100a to form the base of the truss structure as a whole. (not shown). The base portion is fixed directly or indirectly via another supporting member to a structure constituting a space vehicle such as an artificial satellite.

In FIG. 1, only the support structure 300a and the support structure 300b are drawn as the support structures 300 due to the relationship of the drawing angles, but there are six support structures 300. FIG. Note that when there is no need to distinguish between the support structure 300a and the support structure 300b, both are collectively referred to as the support structure 300. FIG.
One end of the support structure 300 is connected through a reduction gear 400 to a node of three rods forming a mirror stand 800 of the support unit 200 and is supported and fixed.
The other ends of the six supporting structures 300 are respectively attached to six portions on the rear surface of the split mirror 100 to support the split mirror 100 . A pair of two-legged support structures 300 are attached in a V-shape to three nodes of the rods forming the mirror stand 800, respectively, to form a bipod support structure.

The actuator 500 inputs a load to the deceleration device 400 in order to finely adjust the step between the split mirrors. The actuator 500 is, for example, a rotary actuator such as a stepping motor or a geared motor that converts a rotation angle into axial translational movement.
The deceleration device 400 decelerates the input from the actuator 500 .
The actuator 500 and the reduction gear 400 are paired. A pair of actuator 500 and reduction gear 400 is provided for each support structure 300 . That is, there are six pairs of actuators 500 and reduction gears 400 . In FIG. 1, only five pairs are drawn due to the drawing angle.

FIG. 2 is an enlarged view of the support structure 300, the reduction gear 400 and the actuator 500. FIG.
The support structure 300 has one end connected to the split mirror 100 and the other end connected to one side of the reduction gear 400 . The other side of the reduction gear 400 is supported and fixed to three node portions of a rod that constitutes the mirror stand 800 . A reduction gear 400 is connected to an actuator 500 . Actuator 500 is supported by holder 501 and connected to reduction gear 400 . In FIG. 2, the holder 501 is represented by a dashed line in order to make the connection between the reduction gear 400 and the actuator 500 easier to understand.
As described above, in the structure 600 of the reflector support mechanism 700, there are six sets of the support structure 300, the reduction gear 400, and the actuator 500. FIG.
FIG. 3 is a view of FIG. 2 viewed from another angle. FIG. 3 shows the support structure 300, the speed reducer 400, and the actuator 500 viewed from the front perpendicular to the longitudinal direction (hereinafter referred to as the axial direction) of the support structure 300. FIG. In FIG. 3, illustration of the holder 501 is omitted.
The support structure 300 is provided with leaf spring-like flexible elastic bodies so as to bend in the directions of two orthogonal axes perpendicular to the axial direction with slight minute displacements. It forms a pseudo-free joint of biaxial rotation capable of minute angular displacement.

FIG. 4 shows details of the reduction gear 400 . Also in FIG. 4, illustration of the holder 501 is omitted. In the deceleration device 400, the axial length of the support structure 300 slightly expands and contracts with nanometer accuracy according to the driving of the actuator 500, and the distance between one side and the other side changes. It should be noted that the minute angular displacement of the flexible elastic body constituting the support structure 300 is extremely small to such an extent that it does not affect the axial length change of the speed reducer 400 .
The deceleration device 400 is composed of a lever 401 and a toggle mechanism 402 .
Lever 401 decelerates the input from actuator 500 to 1/n (n is a number greater than 1) and outputs to toggle mechanism 402 at 1/n magnitude of the input from actuator 500 .
Toggle mechanism 402 decelerates the input from lever 401 to 1/m (where m is a number greater than 1) and outputs 1/m of the input from lever 401 to support structure 300 .
That is, when the lever 401 is pushed by the actuator 500 , the lever 401 pulls the toggle mechanism 402 with a displacement of 1/n of the displacement caused by the pushing by the actuator 500 . Further, when the lever 401 is pulled by the actuator 500 , the lever 401 pushes the toggle mechanism 402 with a displacement of 1/n of the displacement caused by being pulled by the actuator 500 .
Further, when the toggle mechanism 402 is pulled by the lever 401 , the displacement caused by the pulling by the lever 401 is 1/m to pull the support structure 300 to which it is connected. Further, when the toggle mechanism 402 is pushed by the lever 401 , the toggle mechanism 402 pushes the support structure 300 , which is the connection destination, with a displacement of 1/m of the displacement due to being pushed by the lever 401 .
As described above, in the reduction gear transmission 400 according to the present embodiment, when the input from the actuator 500 is 1, the output of the toggle mechanism 402 is 1/(n×m).

FIG. 4 shows an example in which the lever 401 reduces the input from the actuator 500 to 1/5 (reduction ratio: 1/5). 4 shows an example in which the toggle mechanism 402 reduces the input from the lever 401 to 1/5 (reduction ratio: 1/5). That is, FIG. 4 shows an example in which the lever 401 and the toggle mechanism 402 reduce the input from the actuator 500 to 1/25 (reduction ratio: 1/25).
A theoretical resolution of 4 nm/pls can be achieved by reducing the resolution of 0.1 μm/pls of the actuator 500 to 1/25 using the lever 401 and the toggle mechanism 402 .

An arbitrary speed reduction ratio of the lever 401 can be realized by adjusting the distance from the point of force to the fulcrum and the distance from the fulcrum to the point of action. In the example of FIG. 4, the distance from the point of force to the fulcrum and the distance from the fulcrum to the point of action are 5:1, so the reduction ratio of the lever 401 is 1/5.
Further, since the toggle mechanism 402 is a rhombic toggle mechanism, an arbitrary speed reduction ratio can be achieved by adjusting the toggle angle θ shown in FIG. FIG. 5 shows a toggle angle (θ=84.3 degrees) for realizing a reduction ratio of 1/5 in the toggle mechanism 402 .

Note that the lever 401 and the toggle mechanism 402 are not non-linear elements such as bearings that have slippage and friction, but elastic hinges. That is, the lever 401 and the toggle mechanism 402 are made of a material that is elastically deformable and has little influence on the surface change of the segmented mirror due to environmental changes (that is, a material that does not absorb/discharge moisture and has little thermal deformation). More specifically, lever 401 and toggle mechanism 402 are made of metal.

***Description of the effect of the embodiment***
As described above, the reduction gear 400 according to the present embodiment can reduce the input from the actuator 500 to 1/(n×m). Therefore, according to the present embodiment, high mirror surface precision can be obtained in the reflecting mirror using the segmented mirror.
More specifically, the speed reducer 400 can pull or push the support structure 300 with an accuracy of the order of 10 nanometers at each of the six speed reducers 400, so that each segmented mirror 100 has six degrees of freedom of position and orientation. can be adjusted with high accuracy, and the step between the segmented mirrors can be adjusted with an accuracy of 10 nanometers.
In actual operation, after matching the length of each rod of the support unit 200 in units of micrometers, fine adjustment is performed using the actuator 500 and the speed reduction device 400, and the segmented mirror is divided with an accuracy of 10 nanometers. It is conceivable to adjust the step between

In addition, in this embodiment, by using the toggle mechanism 402, it becomes possible to receive the load from the actuator 500 in the axial direction of the support structure 300 without offset, and the rod of the support unit 200 is bent (moment ) is possible. Thereby, the rod of the support unit 200 can be designed thinner, and the strain (moment) affecting the segmented mirror 100 can be reduced. Therefore, it is possible to configure the reflecting mirror 1000 by combining the split mirrors while maintaining the mirror surface accuracy between the split mirrors 100 and maintain the mirror surface accuracy of the reflecting mirror 1000 .
In addition, since the load applied to the support structure 300 is not offset from the center of the axis and can support the load, the split mirror is decelerated while maintaining the statically fixed support of the support structure 300. becomes possible.
Further, according to the present embodiment, the speed reduction device 400 is a two-stage speed reduction mechanism including the lever 401 and the toggle mechanism 402, thereby obtaining a compact configuration.

The above-described embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, the scope of applications of the present invention, and the range of applications of the present invention. Various modifications can be made to the above-described embodiments as required.

100 segmented mirror 110 segmented mirror 200 support unit 300 support structure 400
Reduction gear, 401 Lever, 402 Toggle mechanism, 500 Actuator, 501 Holder, 600 Structure, 620 Fixed truss, 650 Adjustment truss, 700 Reflector support mechanism, 800 Mirror stand, 1000 Reflector, 7000 Reflector structure.

Claims (5)

a lever connected to an actuator, a support structure for supporting the reflecting mirror by the split mirror, and a toggle mechanism connected to the lever,
The lever is
When pushed by the actuator, the toggle mechanism is pulled by a displacement of 1/n (where n is a number greater than 1) of the displacement caused by the pushing by the actuator;
When pulled by the actuator, the toggle mechanism is pushed with a displacement of 1/n of the displacement due to the pull by the actuator;
The toggle mechanism is
when pulled by said lever, pulls said support structure with a displacement in the magnitude of 1/m of the displacement due to being pulled by said lever, where m is a number greater than 1;
A deceleration device used in a reflecting mirror support mechanism for supporting the reflecting mirror , wherein when pushed by the lever, the supporting structure is pushed with a displacement of 1/m of the displacement caused by the pushing by the lever . The toggle mechanism is
2. A speed reduction device according to claim 1, which is a diamond-shaped toggle mechanism. The toggle mechanism is
2. A reduction gear as claimed in claim 1 , wherein the support structure is pulled or pushed with an accuracy of the order of 10 nanometers. 2. The reduction gear transmission according to claim 1, wherein said lever and said toggle mechanism are made of metal. A structure comprising the reflecting mirror, the support structure, the actuator, and the speed reduction device according to claim 1.

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