Lightweight transmission shaft system for multi-space camera large size sunshade

Abstract

The application provides a light-weight transmission shaft system for a multi-space camera large-size sunshade, and aims at solving the technical problem that the existing transmission mechanism adopts distributed bearings, resulting in large weight and volume of the transmission mechanism, and it is difficult to control the temperature of the distributed bearings in a rotating state. The application innovatively designs a transmission shaft system comprising a hollow inner rotating shaft, an adapter flange, a ball bearing group, a transmission plate and a connecting ring, which realizes the rotation of the large-size sunshade driven by the small-size driving mechanism through the specific design of each structure, effectively ensures the light weight and small size of the transmission shaft system, reduces the processing and temperature control difficulty, improves the system reliability, and can be widely applied in the multi-space camera large-size sunshade.

Description

TECHNICAL FIELD

[0001] The present application relates to a transmission shaft system, in particular to a lightweight transmission shaft system for a large-size sun-shield of a multi-space camera. BACKGROUND

[0002] With the increasing requirements of space camera detection capability, the aperture of the space camera is gradually increased, and the size of each optical component is also increased accordingly. The sun-shield, as a main functional component of the space camera, also increases in diameter to more than one meter. With the increasing requirements of space exploration, the orbit environment becomes very complex, and a transmission mechanism needs to be added to realize the rotation of the sun-shield. However, due to the weight limitation of the satellite, a lightweight large-size transmission mechanism becomes a key component of the space camera.

[0003] At present, the existing transmission mechanism is mainly composed of a shaft, a rolling bearing and a connecting piece. However, for a large-size sun-shield of more than one meter, there is no corresponding size of rolling bearing that can be used. For a large-size sun-shield, the traditional transmission mechanism usually adopts a distributed bearing. However, the distributed bearing will result in a large weight and volume of the transmission mechanism, and it is difficult to realize temperature control for the distributed bearing in a rotating state. SUMMARY

[0004] The present application aims to solve the technical problem that the existing transmission mechanism adopts a distributed bearing, resulting in a large weight and volume of the transmission mechanism, and it is difficult to realize temperature control for the distributed bearing in a rotating state, and provides a lightweight transmission shaft system for a large-size sun-shield of a multi-space camera.

[0005] A lightweight transmission shaft system for a large-size sun-shield of a multi-space camera, the multi-space camera comprising a main camera and a plurality of cameras arranged outside the main camera, characterized in that it comprises a mounting seat, a driving mechanism and a transmission mechanism.

[0006] The mounting seat is axially provided with a first light passage hole located on the light path of the main camera.

[0007] The driving mechanism comprises a motor reducer assembly and a gear pair. The gear pair comprises a pinion and a hollow gear that are engaged with each other. The motor reducer assembly is fixedly installed on the mounting seat, and its output end is fixedly connected with the pinion, for driving the hollow gear to rotate by driving the rotation of the pinion.

[0008] The transmission mechanism comprises a hollow inner rotating shaft, an adapter flange, a ball bearing set, at least two transmission plates, and a connecting ring; the hollow inner rotating shaft is arranged in the first light transmission hole, with its lower end coaxially and fixedly connected with the hollow gear, and its upper end coaxially and fixedly connected with the adapter flange; the ball bearing set is arranged between the outer sidewall of the hollow inner rotating shaft and the inner sidewall of the first light transmission hole; the lower ends of the plurality of transmission plates are uniformly installed on the adapter flange in a circumferential direction, and are arranged outwardly and upwardly from bottom to top; the connecting ring is provided with a plurality of second light transmission holes on its upper surface, which are arranged on the light paths of the cameras in the plurality of space cameras respectively, and are sequentially and communicatively arranged; the connecting ring is arranged at the upper ends of the plurality of transmission plates, and is used for mounting the large-size solar light shield outside.

[0009] wherein the ratio of the minimum inner diameter of the second light transmission hole corresponding to the light path of the main camera to the inner diameter of the first light transmission hole is greater than 1.5;

[0010] wherein ±α is the rotation angle range of the large-size solar light shield, r1 is 1 / 2 of the lens aperture of the space camera, s is the horizontal distance between the main camera and the central axis of the adjacent camera, r2 is the radius of the light path of the main camera at the upper end of the transmission plate, d1 is the horizontal distance between the center point of the lower end of the transmission plate and the central axis of the main camera, d2 is the horizontal distance between the center point of the upper end of the transmission plate and the central axis of the main camera, L1 is the width of the lower end of the transmission plate, and L2 is the width of the upper end of the transmission plate; the projection of the central axis of the transmission plate on the plane of the connecting ring, the projection of the line connecting the boundary point of the lower end of the transmission plate and the central axis of the main camera on the plane of the connecting ring, and the projection of the line connecting the boundary point of the upper end of the transmission plate and the central axis of the main camera on the plane of the connecting ring are denoted as straight line A, straight line B, and straight line C respectively, the included angle between straight line A and straight line B is denoted as α, and the included angle between straight line A and straight line C is denoted as β. The above parameters need to satisfy:

[0011]

[0012]

[0013] Further, the number of the transmission plates is two.

[0014] The adapter flange comprises a hollow circular ring and two lugs symmetrically connected to the outer side of the hollow circular ring; the hollow circular ring is coaxially and fixedly connected with the upper end of the hollow inner rotating shaft, and the two lugs are respectively fixedly connected with the lower ends of the corresponding transmission plates.

[0015] The mounting seat comprises a mounting disc and a mounting convex ring connected to one side of the mounting disc; the motor reducer assembly is fixedly installed on the mounting convex ring; the first light transmission hole is coaxially arranged on the mounting disc.

[0016] Further, the upper surface of the hollow circular ring is provided with a hollow bearing heat insulation plate. ​

[0017] The hollow bearing heat insulation plate is fixed on the hollow ring through a plurality of screws, and a glass fiber reinforced plastic heat insulation pad is arranged at the position where each screw is connected with the hollow ring.

[0018] Further, an inner side wall of at least one of the two transmission plates is provided with a transmission heat insulation plate.

[0019] The transmission heat insulation plate is fixed on the transmission plate through a plurality of screws, and a glass fiber reinforced plastic heat insulation pad is arranged at the position where each screw is connected with the transmission plate.

[0020] Further, a ratio of a minimum inner diameter of the second light passing hole corresponding to the main camera light path to an inner diameter of the first light passing hole is 2.

[0021] Further, the ball bearing group is two thin-wall angular contact ball bearings arranged back to back, which can effectively improve the rigidity of the transmission shaft system.

[0022] Further, the thin-wall angular contact ball bearing has a P4 grade precision, and the bearing wall thickness is less than 1 / 12 of the bearing inner diameter, thereby further reducing the weight and volume of the transmission shaft system while meeting the precision requirement.

[0023] Further, the transmission plate is made of titanium alloy material.

[0024] An ultra-black coating is arranged on the inner side wall of the transmission plate to avoid the influence of stray light.

[0025] A reinforcing rib is further arranged on the outer side wall of the transmission plate to improve the support strength of the transmission plate.

[0026] Further, a debris protection cover is arranged on the outer side of the hollow gear.

[0027] Further, the motor reducer assembly is a stepper motor with a planetary gear reducer, or a stepper motor with a harmonic gear reducer, or a torque motor with a planetary gear reducer, or a torque motor with a harmonic gear reducer.

[0028] The beneficial effects of the present application compared with the prior art are as follows:

[0029] 1. The present application innovatively designs a transmission shaft system comprising a hollow inner rotating shaft, an adapter flange, a ball bearing group, a transmission plate and a connecting ring, which realizes the rotation of a small-size driving mechanism driving a large-size sunshade through the specific design of each structure, effectively ensures the lightweight and miniaturization of the transmission shaft system, reduces the machining and temperature control difficulty, improves the system reliability, and can be widely applied in a multi-space camera large-size sunshade.

[0030] 2、The hollow bearing heat insulation plate is arranged on the upper surface of the hollow circular ring, and the transmission heat insulation plate is arranged on the inner side wall of the transmission plate, so that the heat generated by sunlight can be prevented from being transmitted to the ball bearing group or the transmission plate, the temperature change of the transmission shaft system caused by uneven heat radiation is avoided, and smooth rotation of the large-size sunshade is effectively ensured.

[0031] 3、The thin-wall angular contact ball bearing is adopted for supporting design, the weight of the whole transmission shaft system is reduced, the machining difficulty is reduced, and the reliability of the transmission shaft system is improved, and in addition, the two thin-wall angular contact ball bearings arranged in back-to-back mode can effectively improve the rigidity of the transmission shaft system. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a structure schematic view of an embodiment of the light-weight transmission shaft system for the multi-space camera large-size sunshade of the application;

[0033] Figure 2 It is a top view of the embodiment; Figure 1

[0034] Figure 3 It is a structure schematic view of the mounting seat in the embodiment;

[0035] Figure 4 It is a structure schematic view of the driving mechanism in the embodiment;

[0036] Figure 5 It is a structure schematic view of the adapter flange in the embodiment;

[0037] Figure 6 It is a mounting schematic view of the ball bearing group in the embodiment;

[0038] Figure 7 It is a related parameter schematic view in the embodiment.

[0039] Specific reference signs are as follows:

[0040] 1-mounting seat, 101-mounting disc, 102-mounting convex ring; 2-motor reducer assembly, 21-step motor, 22-reducer mounting seat, 23-deep groove ball bearing; 3-small gear; 4-hollow large gear; 5-ball bearing group; 6-hollow inner rotating shaft; 7-adapter flange, 71-hollow circular ring, 72-lug; 8-transmission plate; 9-connection ring; 10-hollow bearing heat insulation plate; 11-transmission heat insulation plate; 12-scrap protection cover; 13-large-size sunshade. DETAILED DESCRIPTION

[0041] In order to make the advantages and characteristics of the application more clear, the application is further described in detail below in combination with the drawings and specific embodiments. ​

[0042] As shown in Figure 1 , Figure 2 , a lightweight transmission shaft system for a large-size sunshade of multiple space cameras, comprising a mounting seat 1, a driving mechanism and a transmission mechanism. The lightweight transmission shaft system in this embodiment is applied to a large-size sunshade 13 of three space cameras, which include a main camera and two cameras located on the opposite sides of the main camera. As shown in Figure 3 , the mounting seat 1 comprises a mounting disc 101 and a mounting convex ring 102 connected to one side of the mounting disc 101. The mounting disc 101 is used to mount the transmission mechanism, and the mounting convex ring 102 is used to mount the driving mechanism.

[0043] The driving mechanism comprises a motor reducer assembly 2 and a gear pair. The motor reducer assembly 2 can be a stepper motor with a planetary gear reducer, or a stepper motor with a harmonic gear reducer, or a torque motor with a planetary gear reducer, or a torque motor with a harmonic gear reducer. As shown in Figure 4 , in this embodiment, it is a stepper motor with a planetary gear reducer, which specifically comprises a stepper motor 21, a planetary gear reducer, a reducer mounting seat 22 and a deep groove ball bearing 23. The gear pair comprises a pinion 3 and a hollow gear 4 that mesh with each other. The planetary gear reducer is installed on the output shaft of the stepper motor 21 and is fixed on the mounting convex ring 102 through the reducer mounting seat 22. The planetary gear reducer reduces the rotating speed of the stepper motor 21 and increases the output torque. The deep groove ball bearing 23 is sleeved on the outside of the output shaft of the stepper motor 21, which is used to bear the radial load and axial load when the stepper motor 21 rotates at high speed. The output shaft of the stepper motor 21 is fixedly connected with the pinion 3, which is used to drive the pinion 3 to rotate, and in turn drives the hollow gear 4 to rotate. Since the hollow gear 4 is designed in a hollow spoke style, the weight of the driving mechanism is greatly reduced. In this embodiment, the reduction ratio of the pinion 3 and the hollow gear 4 is 4.5:1, and the reduction ratio of the planetary gear reducer is 24:1. In addition, in order to prevent the debris generated during the meshing of the hollow gear 4 and the pinion 3 from affecting other parts of the space camera, a debris protection cover 12 is preferably arranged on the outside of the gear of the hollow gear 4 in this embodiment to prevent the debris from affecting other parts of the space camera.

[0044] The transmission mechanism comprises a hollow inner rotating shaft 6, an adapter flange 7, a ball bearing set 5, two transmission plates 8 and a connecting ring 9. As shown in Figure 5 , the adapter flange 7 comprises a hollow ring 71 and two lugs 72 symmetrically connected to the outside of the hollow ring 71. As shown in Figure 6As shown, the first light passing hole in the axial direction is arranged on the installation disc 101 and located in the light path of the main camera, the hollow inner rotating shaft 6 is arranged in the first light passing hole, the lower end of the hollow inner rotating shaft 6 is fixedly connected with the hollow gear 4 in a coaxial manner through a screw, and the upper end of the hollow inner rotating shaft 6 is fixedly connected with the hollow annular ring 71 in a coaxial manner through a screw. The ball bearing set 5 is arranged in a coaxial manner between the outer side wall of the hollow inner rotating shaft 6 and the side wall of the first light passing hole, that is, the ball bearing set 5 is arranged on the inner side of the first light passing hole, and the hollow inner rotating shaft 6 is arranged on the inner side of the ball bearing set 5, so as to support the hollow inner rotating shaft 6 through the ball bearing set 5. In the embodiment, the ball bearing set 5 is two thin-wall angular contact ball bearings arranged in a back-to-back manner, which can effectively improve the rigidity of the transmission shaft system. At the same time, the angular contact ball bearing is selected as an angular contact ball bearing with a precision of P4 grade, and the wall thickness of the bearing is less than 1 / 12 of the inner diameter of the bearing, so that the size and weight are small. On the basis of meeting the accuracy requirement, the weight and volume of the transmission shaft system are further reduced. The lower ends of the two transmission plates 8 are fixedly connected with the corresponding lugs 72 respectively, and are arranged outwardly and upwardly from bottom to top, that is, the two transmission plates 8 are symmetrically arranged on the two sides of the hollow annular ring 71. In other embodiments of the application, when the space of the main camera and other cameras is large, three or four transmission plates 8 can also be selected to be arranged, at this time, the number of lugs 72 is also increased correspondingly.

[0045] The connecting ring 9 is provided with three second light passing holes in the axial direction, and the three second light passing holes are sequentially and continuously arranged. The connecting ring 9 is arranged at the upper end of the two transmission plates 8, and is used for externally mounting the large-size sunshade 13. The ratio of the minimum inner diameter of the second light passing hole corresponding to the light path of the main camera to the inner diameter of the first light passing hole is greater than 1.5, and preferably, the ratio of the minimum inner diameter of the second light passing hole corresponding to the light path of the main camera to the inner diameter of the first light passing hole is 2. After installation, the rotation of the hollow gear 4 will drive the hollow inner rotating shaft 6, the adapter flange 7 and the transmission plate 8 to rotate synchronously, and then drive the large-size sunshade 13 to rotate, so as to finally realize the rotation of the large-size sunshade 13 around the center line of the ball bearing set 5.

[0046] Since the transmission shaft system of the application is arranged at the lower part of the large-size sunshade 13 and located in the light path of the main camera, the transmission plate 8 cannot interfere with the light path of the main camera and the light path of the other cameras on the side when the transmission plate 8 stops rotating, therefore, the application not only needs to consider the setting parameters of the transmission plate 8 itself, but also needs to consider the relationship between the setting parameters of the transmission plate 8 and the parameters of the multi-space camera.

[0047] In the embodiment, the parameters of the three space cameras are consistent, for example, the focal length of the main camera is 24mm, the focal length of the wide-angle camera is 18mm, and the focal length of the telephoto camera is 70mm. Figure 7As shown, define θ as the lens field angle of the space camera, 0°<θ<45°, ±α as the angle range of the large-size sunshade 13 movement, 0°<α<45°, r1 as 1 / 2 of the space camera lens aperture, s as the horizontal distance between the main camera and the adjacent camera central axis, H as the vertical distance between the upper end and the lower end of the transmission plate 8, r2 as the radius of the main camera light path at the height H, d1 as the horizontal distance between the lower end center point of the transmission plate 8 and the main camera central axis, and d2 as the horizontal distance between the upper end center point of the transmission plate 8 and the main camera central axis, then:

[0048]

[0049]

[0050]

[0051] The projection of the transmission plate 8 central axis on the plane of the connecting ring 9 is recorded as straight line A, the projection of the line connecting the lower end boundary point of the transmission plate 8 and the main camera central axis on the plane of the connecting ring 9 is recorded as straight line B, and the projection of the line connecting the upper end boundary point of the transmission plate 8 and the main camera central axis on the plane of the connecting ring 9 is recorded as straight line C, then the included angle between straight line A and straight line B is , and the included angle between straight line A and straight line C is . Define L1 as the width of the lower end of the transmission plate 8, and L2 as the width of the upper end of the transmission plate 8, then:

[0052]

[0053]

[0054] When the transmission plate 8 stops rotating without interfering with the light path of the outer side camera, the following formula needs to be met:

[0055]

[0056]

[0057] The width L1 of the lower end of the transmission plate 8 in the embodiment is 150 mm, the width L2 of the upper end of the transmission plate 8 is 210 mm, and the vertical distance H between the upper end and the lower end of the transmission plate 8 is 310 mm.

[0058] In order to ensure the lightweight of the transmission shaft system, the transmission plate 8 is preferably made of titanium alloy material, and its thickness can be reasonably set according to the weight of the large-size sunshade 13 without interfering with the light path. In addition, reinforcing ribs are also arranged on the outer wall of the transmission plate 8, and the thickness of the transmission plate 8 in the embodiment is 20 mm, and the thickness of the reinforcing ribs is 2 mm.

[0059] Since the two transmission plates 8 are located on both sides of the light path of the space camera opposite the transmission shaft system when they stop rotating, a super-black coating is needed on the inner side wall of the transmission plate 8 to avoid the influence of stray light.

[0060] Preferably, a hollow bearing heat insulation plate 10 is arranged on the upper surface of the hollow circular ring 71 to prevent the heat generated by sunlight from being transmitted to the ball bearing set 5 as much as possible. In addition, since the transmission plate 8 installed directly below the large-size sunshade 13 is arranged to face away from the sunlight, and the other transmission plates 8 are arranged to face the sunlight, a transmission heat insulation plate 11 is needed on the inner side wall of the transmission plate 8 arranged to face the sunlight to prevent the heat generated by sunlight from being transmitted to the transmission plate 8 as much as possible. Specifically, the hollow bearing heat insulation plate 10 and the transmission heat insulation plate 11 are respectively fixed on the hollow circular ring 71 and the transmission plate 8 by screws, and a glass fiber reinforced plastic heat insulation pad is arranged at the position where each screw is connected to the hollow circular ring 71 and the transmission plate 8.

[0061] The above description is only used to illustrate the technical solutions of the present application, and is not intended to limit the same. For ordinary skilled persons in the art, the specific technical solutions described in the above embodiments can be modified, or some technical features can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions protected by the present application.

Claims

1. A lightweight drive shaft system for a large-size sunshade of a multi-space camera, the multi-space camera comprising a main camera and multiple cameras disposed outside the main camera, characterized in that: Includes mounting base (1), drive mechanism and transmission mechanism; The mounting base (1) has a first light-transmitting hole axially located on the optical path of the main camera; The drive mechanism includes a motor reducer assembly (2) and a gear pair; the gear pair includes a small gear (3) and a hollow large gear (4) that mesh with each other; the motor reducer assembly (2) is fixedly installed on the mounting base (1), and its output end is fixedly connected to the small gear (3) for driving the hollow large gear (4) to rotate by driving the small gear (3); The transmission mechanism includes a hollow inner shaft (6), a connecting flange (7), a ball bearing assembly (5), at least two transmission plates (8), and a connecting ring (9); the hollow inner shaft (6) is disposed in the first light-transmitting hole, its lower end is coaxially fixed to the hollow large gear (4), and its upper end is coaxially fixed to the connecting flange (7); the ball bearing assembly (5) is disposed between the outer wall of the hollow inner shaft (6) and the side wall of the first light-transmitting hole; the lower ends of the multiple transmission plates (8) are evenly installed on the connecting flange (7) along the circumference, and are inclined outward from bottom to top; the connecting ring (9) is axially provided with multiple second light-transmitting holes located on the optical paths of each camera in the multi-space camera, and the multiple second light-transmitting holes are sequentially connected; the connecting ring (9) is disposed on the upper end of the multiple transmission plates (8) for mounting a large external sunshade (13); Among them, the ratio of the minimum inner diameter of the second light-transmitting aperture corresponding to the optical path of the main camera to the inner diameter of the first light-transmitting aperture is greater than 1.5; Define ±α as the rotation angle range of the large-size solar shade (13), r1 as 1 / 2 of the aperture of the space camera lens, s as the horizontal distance between the central axes of the main camera and the adjacent camera, r2 as the radius of the main camera's optical path at the horizontal height of the upper end of the transmission plate (8), d1 as the horizontal distance between the center point of the lower end of the transmission plate (8) and the central axis of the main camera, d2 as the horizontal distance between the center point of the upper end of the transmission plate (8) and the central axis of the main camera, L1 as the width of the lower end of the transmission plate (8), and L2 as the width of the upper end of the transmission plate (8). The projections of the central axis of the transmission plate (8) onto the plane of the connecting ring (9), the projections of the line connecting the lower boundary point of the transmission plate (8) and the central axis of the main camera onto the plane of the connecting ring (9), and the projections of the line connecting the upper boundary point of the transmission plate (8) and the central axis of the main camera onto the plane of the connecting ring (9) are respectively denoted as lines A, B, and C. The angle between lines A and B is defined as... The angle between line A and line C is Then the above parameters must satisfy: ； 。 2. The lightweight transmission shaft system for a large-size sunshade for a multi-space camera according to claim 1, characterized in that: The number of transmission plates (8) is two; The adapter flange (7) includes a hollow ring (71) and two lugs (72) symmetrically connected to the outside of the hollow ring (71); the hollow ring (71) is coaxially fixed to the upper end of the hollow inner rotating shaft (6), and the two lugs (72) are respectively fixed to the lower end of the corresponding transmission plate (8); The mounting base (1) includes a mounting disc (101) and a mounting ring (102) connected to one side of the mounting disc (101); the motor reducer assembly (2) is fixedly mounted on the mounting ring (102); the first light-transmitting hole is coaxially opened on the mounting disc (101).

3. A lightweight transmission shaft system for a large-size sunshade for a multi-space camera according to claim 2, characterized in that: The upper surface of the hollow ring (71) is provided with a hollow bearing heat insulation plate (10); The hollow bearing heat insulation plate (10) is fixed to the hollow ring (71) by multiple screws, and each screw is provided with a fiberglass heat insulation pad at the position where it is connected to the hollow ring (71).

4. A lightweight transmission shaft system for a large-size sunshade for a multi-space camera according to claim 3, characterized in that: A transmission heat insulation plate (11) is provided on the inner side wall of at least one of the two transmission plates (8); The transmission heat insulation plate (11) is fixed to the transmission plate (8) by multiple screws, and each screw is provided with a fiberglass heat insulation pad at the position where it is connected to the transmission plate (8).

5. A lightweight drive shaft system for a large-size sunshade for a multi-space camera according to any one of claims 1-4, characterized in that: The ratio of the minimum inner diameter of the second light-transmitting aperture to the inner diameter of the first light-transmitting aperture in the corresponding main camera optical path is 2.

6. A lightweight transmission shaft system for a large-size sunshade for a multi-space camera according to claim 5, characterized in that: The ball bearing assembly (5) consists of two thin-walled angular contact ball bearings arranged back to back.

7. A lightweight transmission shaft system for a large-size sunshade for a multi-space camera according to claim 6, characterized in that: The precision grade of the thin-walled angular contact ball bearing is P4. The wall thickness of the thin-walled angular contact ball bearing is less than 1 / 12 of the bearing's inner diameter.

8. A lightweight transmission shaft system for a large-size sunshade for a multi-space camera according to claim 7, characterized in that: The transmission plate (8) is made of titanium alloy. The inner wall of the transmission plate (8) is provided with an ultra-black coating; The transmission plate (8) is also provided with reinforcing ribs on its outer side wall.

9. A lightweight transmission shaft system for a large-size sunshade for a multi-space camera according to claim 8, characterized in that: The hollow gear (4) is provided with a debris protection cover (12) on the outer circumferential side of the gear.

10. A lightweight transmission shaft system for a large-size sunshade for a multi-space camera according to claim 1, characterized in that: The motor reducer assembly (2) is a stepper motor with a planetary gear reducer, or a stepper motor with a harmonic gear reducer, or a torque motor with a planetary gear reducer, or a torque motor with a harmonic gear reducer.

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