A precision linear drive mechanism suitable for space environment

Abstract

The application relates to the technical field of driving mechanisms, in particular to a precise linear driving mechanism suitable for a space environment, which comprises a mounting platform, a motor, a shaft coupling, a fixing seat assembly, an adapter seat, a ball screw pair, a supporting seat assembly, a first linear guide rail pair and a second linear guide rail pair, wherein the mounting platform is of a groove structure; the motor is fixed at the front end through a motor mounting seat; the ball screw pair is arranged between the fixing seat assembly and the supporting seat assembly; the shaft coupling is arranged between the motor mounting seat and the fixing seat assembly; the first linear guide rail pair and the second linear guide rail pair are arranged in parallel; and the adapter seat is arranged on the ball screw pair. The application converts the rotary motion of the motor into the linear motion of the ball nut through the motor driving the ball screw pair to rotate, two rolling linear guide rail pairs provide the track for the motion of the load workbench, and the microswitch arranged on the two sides of the driving mechanism limits the working range, so that the load workbench is prevented from sliding out of the track.

Description

Technical Field

[0001] This application relates to the field of drive mechanism technology, and more specifically, to a precision linear drive mechanism suitable for space environments. Background Technology

[0002] The extravehicular mechanisms of spacecraft such as satellites often need to perform linear movements to achieve their functions. In particular, some scientific experimental payloads must be mounted on extravehicular platforms to conduct related experiments in the space environment. These experiments usually involve the linear movement of internal mechanisms and require high-precision positioning capabilities.

[0003] In the space environment of alternating high and low temperatures, extremely high vacuum, and strong radiation, the lubricant of traditional linear drive mechanisms will rapidly evaporate and decompose. The thermal expansion and contraction of materials will cause changes in the fit clearance of transmission components. In addition, the cold welding effect of materials will cause the mechanism to quickly jam and fail.

[0004] Therefore, it is necessary to design a linear drive mechanism that can maintain stable lubrication performance in extreme space environments. Summary of the Invention

[0005] This application provides a precision linear drive mechanism suitable for space environments, which can drive a load stage to achieve reciprocating linear motion in space environments.

[0006] To achieve the above objectives, this application provides a precision linear drive mechanism suitable for space environments, including a mounting platform, a motor, a coupling, a fixed base assembly, an adapter, a ball screw pair, a support base assembly, a first linear guide pair, and a second linear guide pair. The mounting platform has a groove structure, and the motor, fixed base assembly, and support base assembly are sequentially fixed inside the groove of the mounting platform. The motor is fixed to the front end via a motor mounting seat. The ball screw pair is disposed between the fixed base assembly and the support base assembly. The coupling is disposed between the motor mounting seat and the fixed base assembly, with one end connected to the motor and the other end connected to the ball screw pair. The first linear guide pair is disposed on one side of the edge of the groove on the mounting platform, and the second linear guide pair is disposed on the other side of the edge of the groove on the mounting platform, with the two arranged parallel to each other. The adapter is disposed on the ball screw pair.

[0007] Furthermore, the fixing assembly includes a first base, a first bearing, a bearing cover, a bearing retaining ring, a locking nut, a set screw, and a pad, wherein: the first bearing is fixed inside the first base; the bearing retaining ring is disposed inside the first bearing; the bearing cover is fastened to the front of the first bearing; one end of the ball screw assembly is inserted into the interior of the first bearing and the bearing retaining ring, locked by the locking nut, and fixed by the set screw and the pad.

[0008] Furthermore, the ball screw assembly adopts an installation method with one end fixed and the other end supported, including a ball screw, a ball nut, and balls, with the balls being of the internal circulation type.

[0009] Furthermore, the ball nut is fixed to the adapter with bolts, and drives the adapter to move together.

[0010] Furthermore, the support assembly includes a second base, a second bearing, and a retaining ring, wherein: the second bearing is disposed inside the second base; the other end of the ball screw pair is inserted into the interior of the second bearing and fixed by the retaining ring.

[0011] Furthermore, the first linear guide pair is a reference rolling linear guide pair, and the second linear guide pair is a non-reference rolling linear guide pair. Both have the same structure, including a linear guide, a slider, and balls. The slider slides on the linear guide using the balls.

[0012] Furthermore, the adapter and slider are provided with mounting holes for connecting to an external load table.

[0013] Furthermore, it also includes micro switches, with a first micro switch provided on one side of the fixed base assembly and a second micro switch provided on one side of the support base assembly. Both the first and second micro switches are connected to the control circuit inside the adapter.

[0014] Furthermore, all ball surfaces in the ball screw pair, the first linear guide pair, the second linear guide pair, the fixed seat assembly, and the support seat assembly are sputtered with a MoS2 lubricating film with a thickness of 0.5~2μm.

[0015] Furthermore, it is suitable for temperatures ranging from -55℃ to +100℃, with a vacuum degree of <6.65×10⁻⁶. -3 Pa, radiation dose ≤3×10 5 In a space environment, the rad(Si) can achieve reciprocating linear motion with a load stage straightness ≤10μm / 100mm and a motion parallelism ≤25μm / 100mm, and its service life ≥10 years. 7 change.

[0016] This application provides a precision linear drive mechanism suitable for space environments, which has the following advantages: This application utilizes a motor to drive a ball screw pair, converting the motor's rotational motion into the linear motion of the ball nuts. Two rolling linear guide pairs provide the track for the load table's movement. Microswitches located on both sides of the drive mechanism limit the working range, preventing the load table from slipping off the track. Simultaneously, it can precisely control the final fit dimensions between the balls, slides, and bearings. Solid lubrication treatment is applied to all ball surfaces involved in the ball screw pair, rolling linear guide pairs, fixed seat assembly, and support seat assembly, ensuring long-term stable lubrication performance of the drive mechanism in the extreme environment of space. The entire drive mechanism is lightweight and compact, and multiple drive mechanisms can be combined and installed to achieve multi-degree-of-freedom motion. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings: Figure 1 This is a structural schematic diagram of a precision linear drive mechanism suitable for a space environment, provided according to an embodiment of this application; Figure 2 This is a structural schematic diagram of the fixed seat assembly and ball screw pair provided according to the embodiments of this application; Figure 3 This is a schematic diagram of the adapter provided according to an embodiment of this application; Figure 4 This is a structural schematic diagram of the first linear guide pair (second linear guide pair) provided according to an embodiment of this application; Figure 5 This is a structural schematic diagram of the support base assembly provided according to an embodiment of this application; In the diagram: 1-Mounting platform, 2-Motor, 3-Motor mounting base, 4-Coupling, 5-Fixed base assembly, 51-First base, 52-First bearing, 53-Bearing cover, 54-Bearing retaining ring, 55-Locking nut, 56-Setting screw, 57-Pan block, 6-Adapter, 61-Mounting hole, 7-Ball screw pair, 71-Ball screw, 72-Ball nut, 73-Ball, 8-Support base assembly, 81-Second base, 82-Second bearing, 83-Snap ring, 9-First linear guide pair, 91-Linear guide, 92-Slider, 10-Second linear guide pair, 11-First micro switch, 12-Second micro switch. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0020] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0021] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0022] In addition, the term "multiple" should mean two or more.

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] like Figure 1As shown, this application provides a precision linear drive mechanism suitable for space environments, including a mounting platform 1, a motor 2, a coupling 4, a fixed base assembly 5, an adapter 6, a ball screw pair 7, a support base assembly 8, a first linear guide pair 9, and a second linear guide pair 10. The mounting platform 1 has a groove structure, and the motor 2, fixed base assembly 5, and support base assembly 8 are sequentially fixed inside the groove of the mounting platform 1. The motor 2 is fixed to the front end via a motor mounting seat 3. The ball screw pair 7 is disposed between the fixed base assembly 5 and the support base assembly 8. The coupling 4 is disposed between the motor mounting seat 3 and the fixed base assembly 5, with one end connected to the motor 2 and the other end connected to the ball screw pair 7. The first linear guide pair 9 is disposed on one side of the groove edge of the mounting platform 1, and the second linear guide pair 10 is disposed on the other side of the groove edge of the mounting platform 1, with the two arranged parallel to each other. The adapter 6 is disposed on the ball screw pair 7.

[0025] Specifically, the precision linear drive mechanism for space environments provided in this application embodiment is mainly used to achieve linear reciprocating motion for extravehicular payloads or mechanisms in spacecraft, providing high-precision positioning. The mounting platform 1 is configured with interfaces according to actual application requirements, providing various mounting methods such as embedding and suspension. A groove structure is preferred, and modular design is also possible, enabling multi-degree-of-freedom motion through the combination of multiple drive mechanisms. The motor 2 drives the ball screw assembly 7 to rotate. It is selected based on control accuracy, torque, speed, load capacity, control method, installation space, and the design parameters of the ball screw assembly 7, with a servo motor 2 being preferred. The motor mounting base 3 is used to fix the motor 2, and is designed according to the external dimensions of the motor 2 and the coupling 4. The coupling 4 connects the motor shaft and the screw shaft, and is selected based on torque, speed, rigidity, deviation compensation capability, installation space, etc., with a diaphragm coupling 4 being preferred. The fixed base assembly 5 and the support base assembly 8 are used to fix the ball screw assembly 7. The ball screw assembly 7 is installed with one end fixed and the other end supported. As the main transmission component, it converts the rotational motion of the motor 2 into the linear motion of the ball nut 72. The linear guide assembly is the component that guides and supports the linear motion. The adapter 6 is mounted on the ball nut 72 and, together with the slider 92 on the linear guide assembly, provides the mounting interface for the load table on the drive mechanism.

[0026] Furthermore, such as Figure 2As shown, the fixing assembly 5 includes a first base 51, a first bearing 52, a bearing cover 53, a bearing retaining ring 54, a locking nut 55, a set screw 56, and a spacer 57. Specifically: the first bearing 52 is fixed inside the first base 51; the bearing retaining ring 54 is disposed inside the first bearing 52; the bearing cover 53 is fastened to the front of the first bearing 52; one end of the ball screw assembly 7 is inserted into the interior of the first bearing 52 and the bearing retaining ring 54, locked by the locking nut 55, and fixed by the set screw 56 and the spacer 57. The fixing assembly 5 is mainly used to fix one end of the ball screw assembly 7's screw shaft. The first bearing 52 is preferably a pair of angular contact ball bearings, the set screw 56 is preferably an internal hex bolt, the spacer 57 is preferably made of copper, and other materials are preferably 9Cr18 stainless steel.

[0027] Furthermore, the ball screw assembly 7 adopts an installation method with one end fixed and the other end supported, including a ball screw 71, a ball nut 72, and balls 73, with the balls 73 being in the form of internal circulation.

[0028] Furthermore, such as Figure 3 As shown, the ball nut 72 is fixed to the adapter 6 by bolts and drives the adapter 6 to move together.

[0029] Specifically, such as Figure 4 As shown, one end of the screw shaft of the ball screw assembly 7 is fixed to the fixed base assembly 5, and the other end is fixed to the support base assembly 8. This converts the rotational motion of the motor 2 into the linear motion of the ball nut 72. Using the balls 73, the ball nut 72 is driven to move on the ball screw 71, simultaneously moving the adapter 6 connected to the ball nut 72. Depending on the actual situation, the ball screw assembly 7 can also be equipped with a reverser and a sealing device, etc. The ball nut 73 preferably circulates internally, and the ball nut 73 is preferably made of GCr15 high-carbon chromium bearing steel; other materials are preferably 9Cr18 stainless steel.

[0030] Furthermore, such as Figure 5 As shown, the support assembly 8 includes a second base 81, a second bearing 82, and a retaining ring 83. The second bearing 82 is disposed inside the second base 81. The other end of the ball screw assembly 7 is inserted into the second bearing 82 and fixed by the retaining ring 83. The support assembly 8 is mainly used to support the other end of the ball screw shaft of the ball screw assembly 7. After the screw shaft is inserted into the second bearing 82 and fixed by the retaining ring 83, the entire assembly is then inserted into the second base 81. The second bearing 82 is preferably a deep groove ball bearing, and the material of the support assembly 8 is preferably 9Cr18 stainless steel.

[0031] Furthermore, the first linear guide pair 9 is a reference rolling linear guide pair, and the second linear guide pair 10 is a non-reference rolling linear guide pair. Both have the same structure, including a linear guide 91, a slider 92, and a ball 73. The slider 92 slides on the linear guide 91 using the ball 73.

[0032] Specifically, the linear guide pairs are divided into two: a reference guide pair and a non-reference guide pair. The former provides the installation reference for the latter. The side of the slider 92 of the reference linear guide pair is polished, while the side of the slider 92 of the non-reference rolling linear guide pair is shot-peened. During installation, the reference rolling linear guide pair is first installed using a U-shaped chuck or linear gauge block. Then, the non-reference rolling linear guide pair is installed using the side of the slider 92 of the reference linear guide pair as the reference. The ball bearing 73 is preferably made of GCr15 high-carbon chromium bearing steel, while other materials are preferably 9Cr18 stainless steel.

[0033] Furthermore, the adapter 6 and the slider 92 are provided with mounting holes 61 for connecting to the external load table. The middle position of the external load table is fixed to the ball screw pair 7 via the adapter 6, and the two sides are fixed to the linear guide pair via the slider 92. In this way, when the overall drive mechanism is running, the external load table can achieve reciprocating motion.

[0034] Furthermore, it also includes micro switches. A first micro switch 11 is provided on one side of the fixed base assembly 5, and a second micro switch 12 is provided on one side of the support base assembly 8. Both the first micro switch 11 and the second micro switch 12 are connected to the control circuit inside the adapter 6. The micro switches mainly serve a limiting function. The first micro switch 11 and the second micro switch 12 are arranged on both sides of the drive mechanism. By controlling the connection and disconnection with the sensitive contact control circuit of the adapter 6, the operating range of the drive mechanism is limited.

[0035] Furthermore, all ball surfaces in the ball screw assembly 7, the first linear guide assembly 9, the second linear guide assembly 10, the fixed seat assembly 5, and the support seat assembly 8 are sputtered with a MoS2 lubricating film with a film thickness of 0.5~2μm.

[0036] Specifically, before assembly, the ball screw assembly 7, the first linear guide assembly 9, the second linear guide assembly 10, the first bearing 52, and the second bearing 82 require cleaning. First, steel balls of predetermined dimensions are assembled, and the assembly is run-in for over 200 cycles before disassembly and thorough cleaning. Finally, steel balls with a sputtered MoS2 lubricating film (0.5~2μm thickness) are assembled. The final diameter of the ball 73 is precisely controlled according to the requirements of the raceway and bearings. The lubricating film is prepared in high vacuum using an unbalanced magnetron sputtering deposition method, possessing anti-cold welding, low friction, and self-lubricating properties, ensuring long-term stable lubrication performance of the drive mechanism in the extreme environment of space.

[0037] Furthermore, it is suitable for temperatures ranging from -55℃ to +100℃, with a vacuum degree of <6.65×10⁻⁶. -3 Pa, radiation dose ≤3×10 5 In a space environment, the rad(Si) can achieve reciprocating linear motion with a load stage straightness ≤10μm / 100mm and a motion parallelism ≤25μm / 100mm, and its service life ≥10 years. 7 change.

[0038] Specifically, the precision linear drive mechanism suitable for space environments provided in this application embodiment uses a motor 2 to drive a ball screw pair 7 to rotate, converting the rotational motion of the motor 2 into the linear motion of the ball nut 72. Two rolling linear guide pairs provide the track for the load table's movement. Microswitches arranged on both sides of the drive mechanism limit the working range to prevent the load table from slipping off the track. The surfaces of the balls involved in the ball screw pair 7, linear guide pairs, fixed seat assembly 5, and support seat assembly 8 are all sputtered with a MoS2 lubricating film for solid lubrication treatment, precisely controlling the final ball diameter. This ensures that the drive can operate at -55℃ to +100℃ with a vacuum degree better than 6.65×10⁻⁶. -3 Pa, radiation dose ≤3×10 5 In a space environment, the rad(Si) drives a load stage to achieve reciprocating linear motion with a linearity of no more than 10μm / 100mm and a parallelism of no more than 25μm / 100mm, with a service life of no less than 10 years. 7 change.

[0039] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A precision linear drive mechanism suitable for space environments, characterized in that, This includes a mounting platform, motor, coupling, fixed base assembly, adapter, ball screw pair, support base assembly, first linear guide pair, and second linear guide pair, wherein: The mounting platform has a groove structure, and the motor, the fixed base assembly, and the support base assembly are sequentially fixed inside the groove of the mounting platform; The motor is fixed to the front end by a motor mounting bracket; The ball screw assembly is disposed between the fixed base assembly and the support base assembly; The coupling is disposed between the motor mounting base and the fixed base assembly, with one end connected to the motor and the other end connected to the ball screw pair; The first linear guide pair is disposed on one side of the edge of the mounting platform groove, and the second linear guide pair is disposed on the other side of the edge of the mounting platform groove, and the two are arranged in parallel. The adapter is mounted on the ball screw assembly.

2. The precision linear drive mechanism suitable for space environments according to claim 1, characterized in that, The fixing seat assembly includes a first base, a first bearing, a bearing cover, a bearing retaining ring, a lock nut, a set screw, and a washer, wherein: The first bearing is fixed inside the first base; The bearing retaining ring is disposed inside the first bearing; The bearing cap is fastened to the front of the first bearing; One end of the ball screw assembly is inserted into the interior of the first bearing and the bearing retaining ring, locked by the locking nut, and fixed by the set screw and the pad.

3. The precision linear drive mechanism suitable for space environments according to claim 2, characterized in that, The ball screw assembly is installed with one end fixed and the other end supported, and includes a ball screw, a ball nut, and balls, with the balls being internally circulating.

4. The precision linear drive mechanism suitable for space environments according to claim 3, characterized in that, The ball nut is fixed to the adapter by bolts and drives the adapter to move together.

5. The precision linear drive mechanism suitable for space environments according to claim 4, characterized in that, The support assembly includes a second base, a second bearing, and a retaining ring, wherein: The second bearing is disposed inside the second base; The other end of the ball screw assembly is inserted into the interior of the second bearing and fixed by the retaining ring.

6. The precision linear drive mechanism suitable for space environments according to claim 5, characterized in that, The first linear guide pair is a reference rolling linear guide pair, and the second linear guide pair is a non-reference rolling linear guide pair. Both have the same structure, including a linear guide, a slider, and balls. The slider slides on the linear guide using the balls.

7. The precision linear drive mechanism suitable for space environments according to claim 6, characterized in that, The adapter and the slider are provided with mounting holes for connecting to an external load table.

8. The precision linear drive mechanism suitable for space environments according to claim 7, characterized in that, It also includes micro switches, with a first micro switch provided on one side of the fixed base assembly and a second micro switch provided on one side of the support base assembly. Both the first micro switch and the second micro switch are connected to the control circuit inside the adapter.

9. The precision linear drive mechanism suitable for space environments according to claim 8, characterized in that, All ball surfaces in the ball screw pair, the first linear guide pair, the second linear guide pair, the fixed seat assembly, and the support seat assembly are sputtered with a MoS2 lubricating film with a film thickness of 0.5~2μm.

10. The precision linear drive mechanism suitable for space environments according to claim 9, characterized in that, Suitable for temperatures ranging from -55℃ to +100℃, with a vacuum degree < 6.65 × 10⁻⁶. -3 Pa, radiation dose ≤3×10 5 In a space environment, the rad(Si) can achieve reciprocating linear motion with a load stage straightness ≤10μm / 100mm and a motion parallelism ≤25μm / 100mm, and its service life ≥10 years. 7 change.

Images