CN2344786Y - Double-rotating fiber optic unit positioning device for spectroscopic astronomical telescope - Google Patents

Abstract

The utility model relates to an optical fiber positioning device on the focal plane of an optical fiber spectrum astronomical telescope in a large sky area. It includes a rotary mechanism driven by a control motor through a reduction transmission mechanism to rotate a hollow shaft in the range of ±180°, and an eccentric rotary mechanism relative to the hollow shaft. The positioning plate for fixing the fiber head is placed at the end of the eccentric rotary shaft. The eccentric shaft is parallel to the hollow shaft and perpendicular to the focal plate, and the distance between them is equal to the eccentric gyration radius of the optical fiber head. The fiber optic head always moves on the focal plane of the telescope, and defocusing will not occur. The device is composed of two rotary motion mechanisms, which is easy to ensure the processing accuracy, is convenient to process, and can reduce the manufacturing cost.

Description

Double-rotating fiber optic unit positioning device for spectroscopic astronomical telescope

The utility model relates to the production of a focal plane system of a multi-target optical fiber spectrum astronomical telescope with a large sky area, in particular to an optical fiber positioning device on the focal plane.

When the astronomical telescope is actually observing celestial bodies, the optical fiber positioning device on its focal plane aligns the fiber head with the position of the celestial body's star image, and the collected star image spectrum is transmitted to the spectrometer through the optical fiber. When the telescope changes the observation target in the observation sky area, it needs to be able to conveniently and flexibly adjust the position of the optical fiber receiving head so that it can be accurately aligned with the position of the celestial body to be measured. The optical fiber positioning device should not only have high position accuracy, but also be easy to adjust and locate quickly, so that various observation errors can be corrected at any time. These requirements make the positioning of the fiber head very technically difficult. In the patent CN97211765.2, the larger telescope focal plane is divided into several unit circle areas according to the number of optical fibers, and an R-θ polar coordinate optical fiber positioning unit device is arranged in each unit circle area. Each positioning unit includes a control unit. The motor drives the hollow shaft through the deceleration transmission mechanism to make a rotary motion mechanism that rotates in the range of ±180° to realize theta movement. It also includes a parallelogram four-bar mechanism composed of elastic guide rails to realize radial translation. This patent effectively solves the positioning problem of the optical fiber on the large focal plane multi-objective fiber optic spectroscopic astronomical telescope, the positioning is fast and the positioning accuracy is high, and the observation error can be corrected in real time. However, since this solution uses the elastic guide rail to swing in a circular arc around the elastic hinge on the end face of the hollow shaft when realizing translation, the swing of the optical fiber receiving head will inevitably cause a defocusing phenomenon that deviates from the focal plane of the telescope. The greater the focus. In addition, mechanisms such as elastic guide rails, elastic hinges, and screw nuts are used in the swing mechanism, which not only has a relatively complicated structure, but also increases the factors of error, which is not conducive to ensuring the overall positioning accuracy.

The purpose of this utility model is to overcome the deficiency in CN97211765.2, and replace the polar coordinate optical fiber unit positioning device using the elastic guide rail with a double-rotation optical fiber unit positioning device in each unit positioning circle area, so as to simplify the structure and ensure that There is no out-of-focus phenomenon on the focus panel.

The purpose of this utility model is achieved in the following ways.

The double-rotation optical fiber unit positioning device of the present utility model includes a rotary mechanism in which a hollow shaft is driven by a control motor through a deceleration transmission mechanism to rotate in a range of ±180°. The center of the circle is positioned vertically and through the unit, and the optical fiber used to collect the spectrum is sheathed in the central hole of the hollow shaft. It is characterized in that it also includes an eccentric mechanism that performs eccentric rotation relative to the axis of the hollow shaft. Connected to the support frame on the surface of the hollow shaft, the control motor and its deceleration transmission mechanism are also arranged on the support frame. The eccentric rotary shaft and the hollow shaft are parallel to each other. The center distance L of the two shafts must be controlled within the following range: R2≤ L≤R, where R is the radius of the unit positioning circle. The positioning plate for fixing the fiber head is arranged at the near end of the eccentric rotary shaft. The distance from the center of the end face of the fiber head to the center of the eccentric rotary shaft is equal to the distance L between the eccentric rotary shaft and the hollow shaft, so that the arc-shaped movement track of the center of the end face of the fiber head just passes through the center of the hollow shaft. Its rotation angle θ driven by the control motor is determined by the following formula:

-arcsin R/2L≤θ≤+arcsinR/2L,

Among them, R is the radius of the positioning unit circle, and L is the distance from the center of the end face of the fiber head to the center of the eccentric rotation axis, that is, the center distance between the eccentric shaft and the hollow shaft.

In the above-mentioned central rotary mechanism and eccentric rotary mechanism, in order to eliminate the return error in the transmission process and ensure the positional accuracy of the optical fiber movement, a gap elimination mechanism commonly used in the prior art can be installed in the transmission mechanism, such as a spring to eliminate the gap mechanism, fixed elimination mechanism, etc.

In each unit positioning circle, the utility model makes the optical fiber head for observing celestial bodies and astrology move centrally along with the hollow shaft on the one hand, and on the other hand make eccentric rotary motion relative to the hollow shaft along with the eccentric rotating shaft. Since the axes of the two axes are parallel to each other, the receiving end face of the optical fiber receiving head will not be deflected during the movement. At the same time, the optical fiber connected to the spectrometer passes through the inner hole of the hollow shaft and is fixed by a positioning plate fixed on the eccentric shaft. The positioning of the optical fiber head is controlled and adjusted by two superimposed arc-shaped trajectories. The radial dimensions of the two arcs are within an appropriate range, and the two rotation axes are perpendicular to the plane of the focal plane, so the end face of the fiber head will always move on the focal plane of the telescope, and defocusing will not occur, ensuring the maximum performance of the fiber head Efficiently receive the light energy spectrum of astrology, and have better observation efficiency. In addition, the device is composed of two rotary motion mechanisms, and the whole is a rigid structure that is more convenient to process, which is easy to ensure the processing accuracy and is conducive to improving the positioning accuracy of the overall device during actual use. On the other hand, due to the simple structure and convenient processing, the manufacturing cost can be reduced.

The utility model can be used in general astronomical telescopes, and is particularly suitable for large-sized astronomical telescopes. When used for a large-scale astronomical telescope, many unit devices can be assembled on the same focal plane, for example, when 4000 unit devices described in the utility model are installed on a spherical focal plane with a diameter of φ1.75m, they can be simultaneously Positioning 4,000 optical fibers separately can not only realize simultaneous observation of 4,000 celestial bodies, but also allow observers to easily and quickly adjust their positions when observing different sky areas.

Further description will be made below by accompanying drawings, embodiments and accompanying drawings thereof.

Fig. 1 is a working principle diagram of the utility model.

In the figure, the largest dotted line circle (1) is the unit positioning circle, its radius is set to R, the axis of the hollow shaft passes through the center of the positioning circle 0, and the hollow shaft is controlled by a stepping motor to rotate ±180°. 01 is the location of the axis of the eccentric shaft, the eccentric shaft is supported on the hollow shaft, and the distance between the two shafts is L. The dotted line circle (2) represents the motion track of the eccentric shaft center rotating with the hollow shaft, and its radius is R1. The eccentric rotary mechanism is supported on the component fixedly connected with the hollow shaft. The eccentric shaft and the hollow shaft are parallel to each other. Point 02 represents the center of the end face of the optical fiber head for observing astronomical phenomena. The dotted line arc (3) represents the center of the optical fiber end face The trajectory of the eccentric axis rotating ±θ, in order to ensure that the center of the fiber head can be positioned at the center of the unit circle without observation blind spots, the arc radius R2 must be equal to the axis distance L, that is, L=R1=R2.

Fig. 2 is a structural schematic diagram of an embodiment of the utility model.

In the figure, inside the dotted line frame is the hollow shaft center turning mechanism, and the structure of this part is the same as that described in CN97211765.2. (5) is a hollow shaft, which is fixedly installed on the focus panel (4), and an optical fiber (6) is sheathed in its inner hole. (7) is a support frame fixedly connected to the end face of the hollow shaft, and the stepping control motor (8) is installed on the protrusion of the support frame, and its output shaft is connected with a reduction gear movement pair (9), and (10) is an eccentric The rotary shaft is supported on the other two projections of the support frame by two rolling bearings (11). (12) is a positioning plate, and two axes parallel to each other are arranged on this plate, one of which is sleeved on the eccentric rotary shaft (10), and the other hole is used for installing and fixing the optical fiber head.

Claims (1)

1 one kinds of two revolution fiber unit locating devices that are used for the spectrum astronomical telescope, include a slew gear that drives ± 180 ° of scopes rotations of tubular shaft do by the control motor through reduction gearing mechanism, this tubular shaft is bearing on the telescope focal plane plate, its axis is vertical with focal plane plate and by positioning unit circle center, be set in the tubular shaft center pit in order to the optical fiber of gathering spectrum, it is characterized in that it also includes the eccentric stiffener that a relative tubular shaft axis is done eccentric gyration, eccentric axis of rotation is arranged on the bearing support that is connected in the tubular shaft surface, on this bearing support, also be provided with control motor and reduction gearing mechanism thereof, eccentric axis of rotation and tubular shaft are parallel to each other, diaxon axle center distance L must be controlled in the following scope: R/2≤L≤R, and wherein R is the cell location radius of circle; Be arranged on the close end of eccentric axis of rotation in order to the location-plate of fixed fiber head; The distance in optical fiber head end surface center to eccentric axis of rotation axle center equals the distance L between eccentric axis of rotation and tubular shaft, and its angle of revolution θ under the control driven by motor is determined by following formula:

-arcsin?R/2L≤θ≤+arcsinR/2L

Wherein, R is the cell location radius of circle, and L is the distance of optical fiber head end surface center to the eccentric axis of rotation heart, i.e. excentric shaft and hollow distance of shaft centers.

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