Temperature control assembly of space manipulator joint

Abstract

The invention relates to the technical field of aerospace, in particular to a temperature control device of a space manipulator joint, which comprises a heating sheet, a heat dissipation surface, a temperature measurement sensor, a heat pipe, a graphite film and a heat insulation material, the heating piece and the heat dissipation face are arranged on the outer wall of an electric box shell of the space manipulator joint and the outer wall of a joint shell of the space manipulator joint except the side wall, where the joint female end of the space manipulator joint is located, of the joint shell. The temperature measuring sensor is arranged on the outer wall of the electric box shell; the heat pipes are installed on the outer walls of the two axial ends of the joint shell through screws. The graphite film is fixed on the inner wall of the joint shell through heat-conducting glue; the outer walls of the joint shell and the electric box shell are covered with the heat insulation material, and except for the heat dissipation face, the heating piece, the temperature measuring sensor and the heat pipe are all covered with the heat insulation material. The heat dissipation device is high in heat dissipation capacity and high in heat dissipation speed, and the problems that heat dissipation is difficult and temperature distribution uniformity is poor during continuous work of a space manipulator joint are solved.

Description

Technical Field

[0001] The invention relates to the field of aerospace technology, and in particular to a temperature control device for a space robot arm joint. Background Art

[0002] The space manipulator is mainly responsible for on-orbit tasks such as cargo handling and astronauts' extravehicular activities, and is usually directly exposed to the cold and dark space environment. As the core actuator of the space manipulator, the joint of the space manipulator needs to be effectively thermally designed to keep the joint within a reasonable temperature range. The thermal design of the space manipulator joint needs to take into account the thermal control difficulties such as the variable on-orbit posture, the large influence of external heat flow, the large power consumption of the internal heat source, and the serious heat leakage at the locking point. Therefore, necessary and efficient temperature control measures need to be adopted.

[0003] Due to the irregular shape of the joint shell of the space manipulator, it is difficult to control the design position of the heat dissipation surface. Therefore, the existing temperature control device of the space manipulator is designed with only one heat dissipation surface. As a result, when the sun shines on the outer wall of the joint where the heat dissipation surface is located, the heat of the space manipulator joint cannot be effectively dissipated during operation, which will increase the overall temperature of the space manipulator joint and cause the motor and other active parts to not work properly. At the same time, this will also result in poor temperature uniformity of components such as the joint shell. Summary of the invention

[0004] In order to solve the problem that the existing temperature control method is difficult to dissipate heat for the joints of a space manipulator when it works continuously on orbit and the temperature distribution is poorly uniform, the present invention provides a temperature control device for the joints of a space manipulator to ensure that the joints of the space manipulator can effectively dissipate heat and have uniform temperature distribution when working on orbit for a long time.

[0005] The temperature control device for the space manipulator joint provided by the present invention comprises a heating plate, a heat dissipation surface, a temperature sensor, a heat pipe, a graphite film and a heat insulation material, wherein:

[0006] The heating plate and the heat dissipation surface are both arranged on the outer wall of the electrical box shell of the space robot arm joint and the outer wall of the joint shell of the space robot arm joint, except for the side wall of the joint shell where the joint female end of the space robot arm joint is located; the temperature sensor is installed on the outer wall of the electrical box shell; the heat pipe is installed on the outer wall of the axial ends of the joint shell by screws; the graphite film is fixed to the inner wall of the joint shell by thermal conductive glue; the heat insulation material is coated on the outer walls of the joint shell and the electrical box shell, and except for the heat dissipation surface, the heating plate, the temperature sensor and the heat pipe are all coated therein.

[0007] Preferably, the temperature control device of the space robot arm joint also includes a control unit, which is electrically connected to the heating plate and the temperature sensor. The control unit receives temperature information collected by the temperature sensor and determines whether to send a control signal based on the temperature information to control the heating plate to heat the joint housing and the electrical box housing.

[0008] Preferably, the heat dissipation direction of the heat dissipation surface includes and is not less than three-dimensional directions.

[0009] Preferably, the installation position of the temperature sensor keeps a distance from the heating plate and the heat dissipation surface to ensure that the normal operation of the temperature sensor is not affected by the heating plate and the heat dissipation surface.

[0010] Compared with the prior art, the present invention can achieve the following beneficial effects: the present invention provides heat dissipation surfaces in no less than three-dimensional directions on the joint housing and the electrical box housing of the space robot arm, ensuring that when one side of the space robot arm joint is exposed to the sun on track, the heat dissipation surfaces in other directions can still effectively dissipate heat; the present invention fixes a graphite film to the inner wall of the joint housing of the space robot arm by means of thermal conductive adhesive, and annular heat pipes are installed on the outer walls at both axial ends by means of screws, thereby improving the heat transfer efficiency of the joint housing of the space robot arm, optimizing the temperature distribution uniformity of the joint of the space robot arm, and enabling the joint of the space robot arm to have stable working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic cross-sectional structural diagram of a temperature control device for a space robot arm joint provided according to an embodiment of the present invention.

[0012] Figure 2 It is a side structural schematic diagram of a temperature control device for a space robot arm joint provided according to an embodiment of the present invention.

[0013] Figure numerals: temperature sensor 1, graphite film 2, thermal insulation material 3, heat pipe 4, joint housing 5, thermal conductive adhesive 6, heat dissipation surface 7, heating plate 8, electrical box housing 9, joint female end 10, joint male end 11 and end cover 12. DETAILED DESCRIPTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same modules are represented by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, the detailed description thereof will not be repeated.

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0016] Figure 1The cross-sectional structure of the temperature control device of the space robot arm joint provided by the embodiment of the present invention is shown; Figure 2 A side view structure of a temperature control device for a space robot arm joint provided according to an embodiment of the present invention is shown.

[0017] like Figure 1-Figure 2 As shown, the temperature control device for the space manipulator joint provided by the present invention comprises a heating plate 8, a heat dissipation surface 7, a temperature sensor 1, a heat pipe 4, a graphite film 2 and a heat insulation material 3, wherein:

[0018] The heating plate 8 and the heat dissipation surface 7 are both arranged on the outer wall of the electrical box housing 9 of the space robot arm joint and the outer wall of the joint housing 5 of the space robot arm joint, except for the side wall of the joint housing 5 where the joint female end 10 of the space robot arm joint is located; the temperature sensor 1 is installed on the outer wall of the electrical box housing 9; the heat pipe 4 is installed on the outer wall of the axial ends of the joint housing 5 by screws; the graphite film 2 is fixed to the inner wall of the joint housing 5 by thermal conductive glue 6; the heat insulation material 3 is coated on the outer walls of the joint housing 5 and the electrical box housing 9, and except for the heat dissipation surface 7, the heating plate 8, the temperature sensor 1 and the heat pipe 4 are all coated therein.

[0019] The temperature control device of the space manipulator joint also includes a control unit, which is electrically connected to the heating plate 8 and the temperature sensor 1. The control unit receives the temperature information collected by the temperature sensor 1, and determines whether to send a control signal based on the temperature information to control the heating plate 8 to heat the joint housing 5 and the electrical box housing 9. The number and power of the heating plates 8 need to be designed according to the temperature index requirements of the various components of the joint. The temperature index generally makes certain requirements for the motor, electrical box, motion mechanism, etc. to ensure that the joint can work stably on track at a reasonable ambient temperature. Please refer to the following table for the temperature index range of each component of the joint:

[0020] Reliability analysis of heating sheet 8:

[0021] Serial number Part Name Working temperature(℃) 1 Joint Shell 5 -30～+50 2 Joint electric box 9 -30～+50 3 Motor -30～+80

[0022] The heating plate 8 adopts H-125 or H-150 polyimide film type heating plate 8, and adopts two control modes: remote control heating and automatic control heating.

[0023] a) The polyimide film type heating sheet 8 used in it has been widely used on my country's satellites. Currently, it has been in orbit for nearly 10 years without any signs of failure;

[0024] b) Corresponding reinforcement measures are taken for the pasting of the heating plate 8 and the welding of the leads, such as applying silicone rubber near the welding points of the leads of the heating plate 8 to strengthen the fixation between the roots of the leads and the mounting surface.

[0025] The heat dissipation surface 7 proposed in the embodiment of the present invention can be set in the form of spraying white paint or other high-emission and low-absorption pigments. The absorption rate of white paint to solar radiation is about 0.12-0.16, and the absorption rate of infrared radiation is 0.90-0.95. The heat dissipation direction of the heat dissipation surface 7 includes and is not less than three-dimensional directions. The three-dimensional directions are +X, -X, +Y, -Y, +Z, and -Z directions of the spatial rectangular coordinate system. Since the joint housing 5 is a cylindrical structure, the heat dissipation direction of the heat dissipation surface 7 can be set in directions other than the three-dimensional direction according to the heat dissipation requirements and structural characteristics of the space robot arm joint.

[0026] The installation position of the temperature sensor 1 is kept away from the heating plate 8 and the heat dissipation surface 7 to ensure that the normal operation of the temperature sensor 1 is not affected by the heating plate 8 and the heat dissipation surface 7. The temperature sensor 1 includes a temperature relay or a thermistor.

[0027] Reliability analysis of thermistors:

[0028] a) The MF501 thermistor used has many successful aerospace application experiences;

[0029] b) Thermistors with 2% accuracy are used for ground unit tests, and thermistors with 1% accuracy are used for initial sample identification parts and genuine flight products.

[0030] The axial ends of the joint housing 5 are the joint male end 11 and the end cover 12 respectively. The heat pipe 4 is fixed at the interface between the joint male end 11 and the joint housing body and the end cover 12 and the joint housing body respectively, which further maintains the uniformity of the circumferential temperature distribution at the axial ends of the joint housing 5.

[0031] Since the material of the space manipulator joint housing 5 is generally a titanium alloy with a thermal conductivity of 5.44W / (m·K), and the thermal conductivity of the graphite film 2 is 1200W / (m·K), the provision of the graphite film 2 can increase the heat transfer efficiency of the space manipulator joint housing 5 by 3 to 5 times. This not only effectively improves the temperature uniformity of the space manipulator joint housing 5, but also provides a stable working environment for the movable parts inside the space manipulator joint.

[0032] In addition, in order to prevent heat leakage from other components of the space robot arm joint, the joint male end 11, the end cover 12 and the joint female end 10 are coated with insulation material 3. Since the surface structures of the joint male end 11, the end cover 12 and the joint female end 10 are irregular, the coating of the insulation material 3 needs to be designed according to the structure of the joint male end 11, the end cover 12 and the joint female end 10. The coating of the joint male end 11, the end cover 12 and the joint female end 10 belongs to the existing technology and will not be introduced in detail here.

[0033] Reliability analysis of thermal insulation material 3:

[0034] a) The heat insulating material 3 used and the fixing method of the heat insulating material 3 (velcro type) have been used on domestic and foreign satellites and have been flight-verified;

[0035] b) The insulation material 3 used has good performance. The mask is made of external anti-atomic oxygen cloth, which can withstand the alternating temperature of -180 to +100°C and has high stability in the space radiation environment. The background radiation energy of the universe is about 10^(-5)W / m 2 , which is equivalent to 4K absolute blackbody radiation. At the same time, the geometric size of the satellite body is negligible compared to the outer space, and all its external radiation energy enters the outer space. When conducting thermal design and thermal analysis, the ambient temperature is generally set to 4K.

[0036] When the space manipulator joint is not working, in order to avoid damage to the space manipulator joint under the influence of ambient temperature, the embodiment of the present invention utilizes a heating plate 8 and a thermal insulation material 3 to ensure that the space manipulator joint is still within the temperature index range in the 4K cold black space environment, wherein the temperature sensor 1 collects the real-time temperature of the electrical box housing 9, and only when the real-time temperature of the electrical box housing 9 is lower than the preset temperature, the heating plate 8 is triggered to start working, and at the same time, a graphite film 2 is fixedly connected to the inner wall of the space manipulator joint housing 5 by a thermal conductive adhesive 6, and annular heat pipes 4 are respectively installed on the +X and -X sides of the joint housing 5, which ensures effective heat conduction around the joint housing 5. This feature can better improve the uniformity of temperature distribution of the space manipulator joint when it is in orbit. When the space manipulator joint is working, the brake, motor and harmonic reducer inside the space manipulator joint housing 5 and the external electric box will generate a lot of heat. At this time, the heat dissipation surface 7 arranged on the space manipulator joint housing 5 and the electric box housing 9 will direct the heat to the cold and dark space environment. When a certain direction of the space manipulator joint is facing the sun, the heat dissipation surface 7 facing the sun will not be able to effectively dissipate heat, but the heat dissipation surfaces 7 in other directions can still ensure that the heat generated when the space manipulator joint is working is directed to the cold and dark space environment.

[0037] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0038] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A temperature control device for a space robot arm joint, characterized in that: It includes a heating plate, a heat dissipation surface, a temperature sensor, a heat pipe, a graphite film and a heat insulation material, among which: The heating plate and the heat dissipation surface are both arranged on the outer wall of the electrical box shell of the space robot arm joint and the outer wall of the joint shell of the space robot arm joint, except for the side wall of the joint shell where the joint female end of the space robot arm joint is located; the temperature sensor is installed on the outer wall of the electrical box shell; the heat pipe is installed on the outer walls of the axial ends of the joint shell by screws; the graphite film is fixed to the inner wall of the joint shell by thermal conductive glue; the heat insulation material is coated on the outer walls of the joint shell and the electrical box shell, and except for the heat dissipation surface, the heating plate, the temperature sensor and the heat pipe are all coated therein.

2. The temperature control device for a space manipulator joint according to claim 1, characterized in that: The temperature control device of the space robot arm joint also includes a control unit, which is electrically connected to the heating plate and the temperature sensor. The control unit receives temperature information collected by the temperature sensor and determines whether to send a control signal based on the temperature information to control the heating plate to heat the joint housing and the electrical box housing.

3. The temperature control device for a space manipulator joint according to claim 1, characterized in that: The heat dissipation direction of the heat dissipation surface includes and is not less than three-dimensional directions.

4. The temperature control device for a space manipulator joint according to claim 1, characterized in that: The installation position of the temperature measuring sensor keeps a distance from the heating plate and the heat dissipation surface, so as to ensure that the normal operation of the temperature measuring sensor is not affected by the heating plate and the heat dissipation surface.

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