1. The three-mirror turntable system with high precision, high stability and timely locking comprises a turntable outer ring (1), a turntable bearing (2) and a turntable inner ring (3) which are sequentially connected through screws, wherein a brushless torque motor (4) is fixed between the turntable outer ring (1) and the turntable inner ring (3); the method is characterized in that: the brake system also comprises an absolute encoder (6), an encoder transition seat (7), a brake adapter seat (8) and a permanent magnet band-type brake (9);

the permanent magnetic band-type brake (9) consists of a permanent magnetic band-type brake rotating part (91) and a permanent magnetic band-type brake fixing part (92);

the rotary table inner ring (3) penetrates through a center hole of the absolute type encoder (6), and a fixed body of the absolute type encoder (6) is connected to the rotary table outer ring (1) through an encoder base (5);

then, the rotary part of the encoder is connected with the inner ring (3) of the rotary table through a screw by the transition seat (7) of the encoder;

the encoder transition seat (7) is connected with the brake adapter (8), the rotating part (91) of the permanent magnetic band-type brake is connected with the brake adapter (8), and the fixing part (92) of the permanent magnetic band-type brake is connected with the brake base (10); the brake base (10) is fixedly connected with the turntable outer ring (1).

2. The high precision, high stability, timely lockable three mirror turret system of claim 1, wherein:

the permanent magnetic band-type brake (9) is a brake which is locked when power is off and unlocked when power is on; the unlocking is realized by counteracting the electromagnetic force generated by electrifying and the original permanent magnetic force, and the rotating part (91) of the brake is strongly sucked by the permanent magnetic force after the power is off, so that the locking is completed.

3. The high precision, high stability, timely lockable three mirror turret system of claim 1, wherein:

the rotating part (91) of the permanent magnet band-type brake comprises a rotating main body, a metal diaphragm and a brake block; the brake block is connected with the rotating body through a metal diaphragm.

4. The high precision, high stability, timely lockable three mirror turret system of claim 1, wherein:

and the absolute encoder (6) and the permanent magnet band-type brake (9) are coaxially mounted with the whole turntable.

5. The high precision, high stability, timely lockable three mirror turret system of claim 1, wherein:

the outer ring (1) of the rotary table and the inner ring (3) of the rotary table are made of 40Cr materials, and the encoder base (5), the encoder transition base (7), the brake adapter base (8) and the brake base (10) are made of aluminum alloy materials.

Background

The high-precision rotary table system is very important for the development of telescope technology, and particularly for a telescope system with a nano focus adopting a three-mirror folded light path, the three mirrors fold light rays from a primary mirror and a secondary mirror into optical systems at different angle positions through precise rotation. For example, the three mirrors horizontally fold the light into the Kudet optical path at the initial position, and then enter the lower optical platform of the machine through the Kudet optical path to perform precise imaging; meanwhile, the three mirrors rotate by 90 degrees, so that light can be introduced to an optical detection platform on the machine, and other optical functions are realized. Therefore, in more and more precise foundation large-caliber optical telescope systems, a three-mirror turntable system for realizing different function switching is increasingly critical. There is a need to design a high precision, high stability turntable system with an automatic locking function to meet the overall requirements of all-electric operation.

The existing mature precision turntable system generally adopts a form that a precision turntable bearing is matched with a brushless torque motor, and is generally divided into an inner shaft and an outer shaft, and the scheme is mature as a driving operation part of the high-precision turntable bearing and has wide application; however, the existing turntable braking system has the defects of low speed and large braking swing, because the existing turntable braking scheme generally adopts a disc braking system similar to automobile braking, a locking block fixed on an outer ring is driven by a stepping motor, a brake disc rotates along with the inner ring, and when a braking holding position is needed, the stepping motor drives the locking block to gradually clamp the brake disc, and finally the braking of the inner ring is realized. Therefore, the prior art scheme is that the precision bearing-torque motor-disc brake locking is realized, and a quasi-absolute type or absolute type encoder is used for assisting, so that the precision quantitative angle rotation and locking are realized.

The driving and running part of the existing design is mature, but the turntable locking part has the problems of low action execution speed, small locking torque and influence on system precision due to locking jitter. The brake disc is gradually clamped by adopting a stepping motor to drive the locking block, the execution time of unlocking-locking actions is overlong, usually 30s-1min, whether the locking or unlocking is carried out cannot be directly fed back, monitoring can be carried out only by arranging 2 photoelectric switches on the operation route of the locking block, and the design difficulty of the assembly is invisibly increased; in addition, the locking torque of the scheme depends on the static friction force of the locking block clamping the brake disc, the thrust of the stepping motor is limited, and meanwhile, after the surface of the brake disc is rubbed for a long time, the friction coefficient is reduced, so that the locking torque is limited and can be reduced gradually due to synthesis; finally, the stepping motor locking assembly is usually arranged at the edge of the rotary table, and belongs to eccentric arrangement, the operation of the stepping motor and the clamping process of the locking block can generate eccentric vibration, the eccentric vibration is conducted to the mirror surface through the three-mirror assembly, the stability of light rays refracted by the three mirrors is finally influenced, and particularly for an optical system with a long focal length, the vibration and the shaking generated at the three mirrors can cause large deviation at a terminal.

Therefore, the invention aims to design a three-mirror turntable system which has high precision and stability and can be locked in time, has the characteristics of large locking moment, high operation stability, small influence and short action execution time, solves the existing problems through innovative design and application, and provides guidance for the application of a high-precision turntable in the future telescope technology.

Disclosure of Invention

The invention provides a three-mirror turntable system which is high in precision and stability and can lock in time, and aims to solve the problems of locking, unlocking, executing stability and the like of a three-mirror turntable in the telescope technology.

The three-mirror turntable system with high precision, high stability and timely locking comprises a turntable outer ring, a turntable bearing and a turntable inner ring which are sequentially connected through screws, wherein a brushless torque motor is fixed between the turntable outer ring and the turntable inner ring; the device also comprises an absolute encoder, an encoder transition seat, a brake adapter and a permanent magnet band-type brake;

the permanent magnetic band-type brake comprises a permanent magnetic band-type brake rotating part and a permanent magnetic band-type brake fixing part;

the inner ring of the rotary table penetrates through a center hole of the absolute type encoder, and the fixed main body of the absolute type encoder is connected to the outer ring of the rotary table through the encoder base;

then, the rotary part of the encoder is connected with the inner ring of the rotary table through the transition seat of the encoder;

the encoder transition seat is connected with the brake adapter, the rotating part of the permanent magnetic band-type brake is connected with the brake adapter, and the fixed part of the permanent magnetic band-type brake is connected with the brake base; and the brake base is fixedly connected with the outer ring of the rotary table.

The invention has the beneficial effects that:

the three-mirror rotary table system with high precision, high stability and timely locking is characterized in that the locking and unlocking of the rotary table are completed through the coaxially arranged electric control permanent magnet band-type brake, and compared with the existing commonly used eccentric disc brake locking and unlocking mechanism, the three-mirror rotary table system can greatly reduce the action operation time and realize instantaneous unlocking and locking; compared with disc brake mechanical locking, the permanent magnet locking torque is larger and basically has no attenuation; meanwhile, in the aspect of stability during locking and unlocking, the scheme of coaxial arrangement and locking block connection by the membrane adopted by the invention is far superior to the scheme of eccentric arrangement and disc brake friction locking in the prior art;

the absolute encoder adopted by the invention is coaxial and internally arranged, and has compact transition connection with the inner ring of the rotary table and the outer ring of the rotary table, and reasonable and efficient overall layout. The three-mirror turntable system with high precision, high stability and timely locking can greatly increase the efficiency and stability of the azimuth-changing movement of the telescope three-mirror mechanism system, and the turntable is also suitable for other high-precision rotating systems.

The three-mirror turntable system is already put into manufacturing and use of a prototype, and through actual experimental test and use effect evaluation, the generated system shaking error is better than 3' and the locking torque is better than 40NM (the peak torque of the adopted torque motor is 25NM) in the locking and unlocking processes of the permanent magnet band-type brake.

Drawings

Fig. 1 is a central plane sectional view of a high-precision, high-stability and timely-locking three-mirror turntable system according to the present invention.

Fig. 2 is a schematic diagram of a permanent magnet band-type brake device and a related connecting adapter.

Fig. 3 is an explosion schematic diagram of the permanent magnet band-type brake device.

Fig. 4 is a schematic view of an encoder transition seat.

Fig. 5 is a schematic view of the brake adapter.

FIG. 6 is a schematic view of an encoder base.

In the figure: 1. the rotary table comprises a rotary table outer ring, 2 a rotary table bearing, 3 a rotary table inner ring, 4 a brushless torque motor, 5 an encoder base, 6 an absolute encoder, 7 an encoder transition base, 8 a brake adapter, 9 a permanent magnet band-type brake, 91 a brake rotating part, 92 a brake fixing part, 10 a brake base.

Detailed Description

In order to make the technical solutions of the present invention better understood, those skilled in the art will now describe the present invention in further detail with reference to the accompanying drawings.

It should be noted that the terms "on", "between", and the like used in the present embodiment refer to the orientation or positional relationship shown in the drawings only for the convenience of describing the present invention and simplifying the description, and the similar expressions are only for the purpose of explanation, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus are not to be construed as limiting the present invention, and furthermore, the terms "first", "second", and "second" are only used for descriptive purposes and are not to be construed as indicating or implying relative importance.

The following describes the three-mirror turret system of the present embodiment, which is high precision, high stability, and capable of locking in time, with reference to fig. 1 to 6, and includes: the rotary table comprises a rotary table outer ring 1, a rotary table bearing 2 and a rotary table inner ring 3 which are connected in sequence through screws;

the turntable bearing 2 and the brushless torque motor 4 are connected with the turntable outer ring 1 and the turntable inner ring 3 sequentially through screws;

a brushless torque motor 4 is fixed between the turntable outer ring 1 and the turntable inner ring 3; the device also comprises an absolute encoder 6, an encoder transition seat 7, a brake adapter 8 and a permanent magnet band-type brake 9;

the permanent magnetic band-type brake 9 consists of a permanent magnetic band-type brake rotating part 91 and a permanent magnetic band-type brake fixing part 92;

the rotary table inner ring 3 penetrates through a center hole of the absolute type encoder 6, and a fixed body of the absolute type encoder 6 is connected to the rotary table outer ring 1 through an encoder base 5;

then, the rotary part of the encoder is connected with the inner ring 3 of the rotary table through the transition seat 7 of the encoder through screws;

the encoder transition seat 7 is connected with the brake adapter 8, the permanent magnet band-type brake rotating part 91 is connected with the brake adapter 8, and the permanent magnet band-type brake fixing part 92 is connected with the brake base 10; the brake base 10 is fixedly connected with the turntable outer ring 1.

After the detection is finished, the detection is carried out, and the power is switched on and the operation detection is carried out, so that the rotating table is ensured to rotate stably.

In the embodiment, the absolute encoder 6 is coaxially mounted with the whole rotary table, and the absolute encoder 6 is arranged inside the rotary table and between the brushless torque motor 4 and the permanent magnet band-type brake 9. The center hole of the absolute encoder 6 is aligned with the turntable inner ring 3 and is sleeved, namely: the inner ring 3 of the rotary table penetrates through the middle hollow area of the encoder; aligning and connecting the encoder fixing main body with the spigot of the encoder base 5, and locking the screw; the fixed main body of the encoder is connected with the outer ring 1 of the rotary table through the encoder base 5, and the middle of the outer ring 1 of the rotary table is provided with a spigot which is matched with the installation surface of the encoder.

The rotating part of the absolute encoder 6 is connected with the rotary table inner ring 3 through an encoder transition seat 7, and meanwhile, the encoder transition seat 7 is connected with a brake adapter 8 to transmit the rotation of the inner ring to a permanent magnet band-type brake 9.

In this embodiment, the rotating part 91 of the permanent magnetic band-type brake is connected with the encoder transition seat 7 through the brake adapter 8, and further connected with the turntable inner ring 3; the brake fixing portion 92 is connected to the turntable outer ring 1 through the brake base 10; and completing the connection of all the components of the rotary table.

Referring to fig. 3, the rotating part 91 of the permanent magnetic band-type brake comprises a brake block 913, a rotating body 911 and a metal diaphragm 912; the brake blocks 913 are connected with the rotating main body 911 through metal membranes 912, 3 parts are uniformly distributed, and the discrete metal membranes 912 at 3 parts form the effect similar to a coupler, so that shaking and impact shaking are reduced when permanent magnets are tightly absorbed.

In the embodiment, the unlocking and locking mechanism adopts a rotary table coaxial unlocking and locking technology based on a permanent magnet band-type brake, and a permanent magnet band-type brake 9 is arranged at the tail end of the rotary table and is coaxially connected with the rotary table inner ring 3 and the rotary table outer ring 1.

The permanent magnetic band-type brake 9 is locked in a power-off mode and unlocked in a power-on mode; the unlocking is realized by counteracting the electromagnetic force generated by electrifying and the original permanent magnetic force, otherwise, the permanent magnetic force strongly attracts the rotating part 91 of the brake after the power is off, and the locking is finished; thus the locking and unlocking actions are completed instantly; meanwhile, the adopted permanent magnet is a strong magnet, the attraction force is large, and the locking torque is large by matching with a wear-resistant brake block with a large friction coefficient.

The whole layout of the rotary table system is compact and clear, the rotary table bearing 2, the brushless torque motor 4, the absolute encoder 6 and the permanent magnet band-type brake 9 are all coaxially arranged, and eccentric torque and vibration are not generated, and are not generated.

In the present embodiment, the turntable inner ring 3 is made of 40Cr material. The outer ring 1 of the turntable is made of 40Cr materials. The brake adapter 8 is made of aluminum alloy material. The encoder transition seat 7 is made of aluminum alloy materials. The brake base 10 is made of an aluminum alloy material. The encoder base 5 is made of aluminum alloy material.

The embodiments described above are only for explaining the present invention, the protection scope of the present invention should include the whole contents of the claims, and the whole contents of the claims of the present invention can be realized by those skilled in the art through the embodiments.