Space locking mechanism driven by ultrasonic motor

Abstract

The invention provides a space locking mechanism driven by an ultrasonic motor, which is characterized in that the space locking mechanism comprises a driving end mounted on an aircraft and a driven end mounted on a space station, the driving end comprises a driving assembly (6) and an executing mechanism assembly (7), and the driven end comprises a driven lock hook (14). The driving assembly (6) comprises an ultrasonic motor (1) with a power-off self-locking function and a three-stage planetary reducer (2), the executing mechanism assembly (7) comprises a shell (3), a crank sliding block mechanism and a disc spring (13), a crank (5) is provided with an involute internal spline and is matched with an involute external spline of a planet carrier to work, the crank (5) drives a connecting rod (12) to move, the shell (3) is combined, so that a driving lock hook (4) moves in the vertical direction, and the driving lock hook (4) is locked. And the disc spring (13) is compressed synchronously. The self-locking function is achieved through the ultrasonic motor and the crank dead point, the disc spring enables the mechanism to keep large locking force for a long time, and the self-locking mechanism has the advantages of being long in service life, high in reliability and light in passive end weight.

Description

Technical Field

[0001] The invention relates to a locking mechanism, in particular to a spatial locking mechanism driven by an ultrasonic motor. Background Art

[0002] Applications involving the rendezvous and docking of two vehicles, such as spacecraft and space stations, and lunar sample transfers, all require a locking mechanism to secure the two vehicles. While most existing locking mechanisms can achieve this locking function, the active and passive locking ends are of comparable weight. Current locking mechanisms lack the ability to maintain a high, long-term locking force while maintaining a lightweight passive end.

[0003] Based on the search terms, 5 relevant patent documents were initially retrieved, among which the documents that are particularly relevant to the present invention are as follows.

[0004] Patent document CN104335703B, "Docking Locking Device," discloses a docking locking device capable of achieving rigid connection, maintaining connection, and safely separating two spacecraft. The present invention differs in that it utilizes an ultrasonic motor and a crank at five dead points to achieve self-locking. A disc spring 13 maintains a high locking force over a long period of time, and the passive end is a lightweight structural component. This locking mechanism offers the advantages of long life, high reliability, and a lightweight passive end.

[0005] A search and comparison of patent document CN107416235B, "A Spatial Docking Repeatable Locking Device," primarily discloses a repeatable locking device that utilizes two symmetrical locking hooks and a locking shaft for locking. The present invention differs in that it utilizes an ultrasonic motor and a crank at five dead points to achieve self-locking. The disc spring 13 maintains a high locking force over a long period of time, resulting in increased reliability.

[0006] A search and comparison of patent document CN114291303B, "A Lightweight and Simplified Docking Locking and Release Device and Its Working Method," primarily discloses a device that uses a screw capture mechanism to achieve the locking function. The present invention differs in that it uses an ultrasonic motor combined with a three-stage planetary reducer to drive a crank slider mechanism to achieve the locking function, and the two operate on different principles.

[0007] A search and comparison of patent document CN112319869B, "A Large Spatial Tolerance Docking Device and Locking Method," primarily discloses a device that relies on a compression spring-driven locking claw mechanism combined with a guide mechanism to achieve docking and locking functions. The present invention differs in that it uses an ultrasonic motor combined with a three-stage planetary reducer to drive a slider-crank mechanism to achieve locking. The disc spring ensures a high, long-term locking force, and the passive end is a lightweight structural component. The two differ in their operating principles and performance.

[0008] A search and comparison of patent document CN113562204B, "A Spatial Electromagnetic Docking Mechanism Based on Mechanical Locking and Electromagnetic Unlocking," primarily discloses a docking mechanism that uses a bead-type locker for locking and electromagnetic release. The present invention differs in that it uses an ultrasonic motor in conjunction with a three-stage planetary reducer to drive a slider-crank mechanism for locking, resulting in a different operating principle. Summary of the Invention

[0009] To address the shortcomings of existing space-based on-orbit locking mechanisms, the present invention relates to a space-based locking mechanism driven by an ultrasonic motor. While maintaining a high locking force over a long period of time, it also possesses a self-locking function and effectively reduces the weight of the passive end. This invention effectively addresses the challenges of achieving a long lifespan for space-based locking mechanisms and achieving a lightweight passive end. The technical solutions of the present invention are as follows:

[0010] A space locking mechanism driven by an ultrasonic motor is characterized in that it includes an active end installed on an aircraft and a passive end installed on a space station. The active end includes a drive assembly 6 and an actuator assembly 7. The passive end is a structural component that cooperates with the active lock hook 4 and includes a passive lock hook 14. The active lock hook 4 and the passive lock hook 14 work together to achieve mechanism locking.

[0011] The driving assembly 6 includes an ultrasonic motor 1 with a power-off self-locking function and a three-stage planetary reducer 2. The ultrasonic motor 1 drives the three-stage planetary reducer 2 to rotate and outputs power through the involute external spline.

[0012] The actuator assembly 7 includes a housing 3, a crank slider mechanism and a disc spring 13. The crank slider mechanism includes a crank 5 and a connecting rod 12. The crank 5 is provided with an involute internal spline, which cooperates with the involute external spline.

[0013] The crank slider mechanism is arranged inside the shell 3, the disc spring 13 is arranged on the upper side inside the shell 3, the lower end of the active locking hook 4 is stuck in the disc spring 13, and is connected to the connecting rod 12, the crank 5 drives the connecting rod 12 to move, and combined with the shell 3, the active locking hook 4 moves in the vertical direction, synchronously compressing the disc spring 13, and the locking holding force is provided by the deformation of the disc spring 13.

[0014] Furthermore, the passive locking hook 14 is a structural component made of high-strength titanium alloy.

[0015] Furthermore, the three-stage planetary reducer 2 includes a sun gear 8, a first-stage planet 9, a second-stage planet 10 and a third-stage planet 11. The ultrasonic motor 1 drives the first-stage planet 9, the second-stage planet 10 and the third-stage planet 11 through the sun gear 8. The planet carrier of the third-stage planet 11 is provided with an involute external spline, and the crank 5 works in cooperation with the external spline of the third-stage planet 11.

[0016] Furthermore, when locking, the active locking hook 4 moves downward in the vertical direction, pulling the passive locking hook 14 to complete the locking function.

[0017] Furthermore, the inner spline rotates, and the active locking hook 4 at the end of the crank slider mechanism reciprocates along a certain range, completing the locking function of the passive end, and at the same time compressing the disc spring 13, so that the locking force gradually increases during the locking process.

[0018] Furthermore, in the locking completion position, the force generated by the compression of the disc spring 13 is the designed locking holding force, which is also the dead point position of the crank 5, realizing the self-locking function of the mechanism.

[0019] Furthermore, the passive locking hook 14 is provided with a rounded corner R5 at the stress concentration location.

[0020] Furthermore, the disc spring 13 is composed of four pieces.

[0021] Furthermore, the disc spring 13 is sleeved on the outside of the cylindrical section of the active locking hook 4 and fixed axially with two nuts. The disc spring 13 is made of 60Si2MnA high-strength spring steel.

[0022] Furthermore, the aircraft is a spacecraft.

[0023] By adopting the above technical solution, the locking mechanism of the present invention achieves a self-locking function through the ultrasonic motor and the crank dead center. The disc spring ensures that the mechanism maintains a high locking force over a long period of time, and the passive end is a lightweight structural component. The ultrasonic motor-driven spatial locking mechanism has the advantages of long life, high reliability, and a lightweight passive end. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0025] Figure 1 is an axonometric view of the ultrasonic motor-driven spatial locking mechanism of the present invention;

[0026] Figure 2 1. It is a diagram of the driving assembly and the executing assembly of the ultrasonic motor-driven spatial locking mechanism of the present invention;

[0027] Figure 3 is a cross-sectional view of a drive assembly of the present invention;

[0028] Figure 4 is a cross-sectional view of an actuator assembly of the present invention;

[0029] Figure 5 Schematic diagram of the passive locking hook of the present invention.

[0030] Description of reference numerals:

[0031] 1. Ultrasonic motor; 2. Three-stage planetary reducer; 3. Housing; 4. Active lock hook; 5. Crank; 6. Drive assembly; 7. Actuator assembly; 8. Sun gear; 9. First-stage planet; 10. Second-stage planet; 11. Third-stage planet; 12. Connecting rod; 13. Disc spring; 14. Passive lock hook. DETAILED DESCRIPTION

[0032] The following is combined with Figures 1 to 5 The specific implementation of the ultrasonic motor-driven spatial locking mechanism of the present invention is described in more detail.

[0033] The ultrasonic motor-driven space locking mechanism of the present invention has a self-locking function, maintains locking force and effectively reduces the weight of the passive end, and is suitable for completing the locking function of two aircraft in space.

[0034] The spatial locking mechanism driven by the ultrasonic motor of the present invention is mainly composed of a drive assembly 6, an actuator assembly 7 and a passive lock hook 14. The drive assembly 6 and the actuator assembly 7 are installed in conjunction with each other and serve as the active end. The active end is installed on an aircraft such as a spacecraft, and the passive end is installed on a space station. The passive end is a structural component that cooperates with the active lock hook 4. The active end of the locking mechanism includes the drive assembly 6 and the actuator assembly 7, and the passive end is a passive lock hook 14 with a lightweight design. The active lock hook 4 contained in the actuator assembly 7 of the active end works in conjunction with the passive lock hook 14 of the passive end to achieve mechanism locking.

[0035] Figure 1 This is an axonometric diagram of the ultrasonic motor driven space locking mechanism of the present invention. The figure shows the position and installation relationship of the ultrasonic motor 1, three-stage planetary reducer 2, housing 3, active locking hook 4, and crank 5 in the ultrasonic motor driven space locking mechanism of the present invention. Figure 1 As shown, the ultrasonic motor 1 is horizontally connected to the three-stage planetary reducer 2 and the housing 3 in sequence, and the crank 5 is installed in the housing 3 and vertically connected to the active locking hook 4.

[0036] Figure 2 1 is a diagram of the driving assembly and the executing assembly of the space locking mechanism driven by the ultrasonic motor of the present invention. Figure 2 The figure shows the outline of the active end drive assembly 6 and the actuator assembly 7, as well as their mechanical interface. The two parts are fixed together by six M5 screws and two matching dowel pins, while the power is transmitted internally by involute splines.

[0037] Figure 3 FIG is a cross-sectional view of the drive assembly of the present invention. Figure 3As shown, the drive assembly 6 includes an ultrasonic motor 1 with a power-off self-locking function and a three-stage planetary reducer 2. As the active end of the drive assembly 6, the ultrasonic motor 1 drives the three-stage planetary reducer 2, reducing the speed and increasing the output torque. The power is then output via the involute external spline. The three-stage planetary reducer 2 includes a sun gear 8, a primary planet 9, a secondary planet 10, and a tertiary planet 11.

[0038] The main working process of the active end drive assembly 6 of the present invention is as follows: the ultrasonic motor 1 with a power-off self-locking function drives the first-stage planet 9, the second-stage planet 10, and the third-stage planet 11 through the sun gear 8. The planet carrier of the third-stage planet 11 is equipped with an involute external spline, which serves as the output end of the drive assembly 6.

[0039] Figure 4 : is a cross-sectional view of the actuator assembly of the present invention. Figure 4 As shown, the actuator assembly 7 includes a housing 3, a slider-crank mechanism, and a disc spring 13. The slider-crank mechanism is located inside the housing 3, and the disc spring 13 is located on the upper side of the housing 3. The slider-crank mechanism includes a crank 5 and a connecting rod 12. The lower end of the active locking hook 4 is engaged in the disc spring 13 and connected to the connecting rod 12.

[0040] The disc spring 13 is sleeved on the outside of the cylindrical section of the active locking hook 4 and fixed axially with two nuts. The disc spring 13 is made of 60Si2MnA high-strength spring steel, and the stiffness of the four disc springs is about 17kN / mm.

[0041] In particular, the ultrasonic motor 1 has a self-locking characteristic when power is off, which can effectively enhance the self-locking ability of the mechanism; the locking holding force is provided by the deformation of the disc spring 13, and the passive end is a simple structural part, which can effectively reduce the weight of the passive end.

[0042] The active-end actuator assembly 7 of the present invention receives torque via crank 5. Crank 5 is equipped with an involute internal spline that cooperates with the external spline of the third-stage planetary gear 11. Crank 5 drives connecting rod 12, which, in conjunction with housing 3, causes active locking hook 4 to move vertically, synchronously compressing four-leaf disc spring 13 and providing a continuous, high locking force. To lock, active locking hook 4 moves vertically downward, pulling passive locking hook 14 to complete the locking function, and then moves upward to unlock.

[0043] Actuator assembly 7 receives power via an involute internal spline, which also serves as crank 5. Rotation of the internal spline causes active locking hook 4 at the end of the slider-crank mechanism to reciprocate within a defined range, locking the passive end while simultaneously compressing disc spring 13, gradually increasing the locking force during the locking process. In the locked position, the force generated by the compression of disc spring 13 equals the designed locking holding force, which also occurs when crank 5 is past dead center, thus achieving the self-locking function of the mechanism.

[0044] Figure 5Schematic diagram of the passive lock hook of the present invention. Figure 5 As shown, the passive locking hook 14 is installed in the space station, and works in conjunction with the active locking hook 4. A fillet R5 is provided at the stress concentration location to improve the stress condition of the passive locking hook.

[0045] When the active locking hook 4 moves downward to its lowest point, the extended section of the crank 5, the connecting rod 12, and the axis of the cylindrical section of the active locking hook 4 are all in a vertical direction. At this point, the mechanism is at a dead center position. The crank 5 continues to rotate about 6 degrees in the locking direction, and the mechanism is in a post-dead center state, capable of maintaining a strong locking force. When the crank slider mechanism is in the post-dead center position, the locked mechanism will not open due to the strong locking force. The mechanism can only be unlocked by rotating the crank 5 in the unlocking direction.

[0046] The ultrasonic motor 1 features a self-locking function when powered off, and the crank slider mechanism also achieves self-locking when past dead center. These two functions together ensure that the locking mechanism maintains excellent self-locking capability in the locked position. The four-leaf disc spring 13 provides approximately 40 kN of locking force in the locked position, with minimal degradation during prolonged locking, ensuring long life. Because both the drive and actuator components are located at the active end, the passive end is designed as a high-strength titanium alloy structure, meeting the requirements for lightweight passive end design.

[0047] It should be noted that the above is only an illustrative description and explanation of the present invention. Those skilled in the art should understand that any modification and replacement of the present invention falls within the scope of protection of the present invention.

Claims

1. A spatial locking mechanism driven by an ultrasonic motor, characterized in that: The invention comprises an active end installed on an aircraft and a passive end installed on a space station, wherein the active end comprises a driving assembly (6) and an actuator assembly (7), and the passive end is a structural component matched with an active locking hook (4), comprising a passive locking hook (14), wherein the active locking hook (4) and the passive locking hook (14) cooperate to realize the locking of the mechanism. The driving assembly (6) comprises an ultrasonic motor (1) with a power-off self-locking function and a three-stage planetary reducer (2). The ultrasonic motor (1) drives the three-stage planetary reducer (2) to rotate, and outputs power through an involute external spline. The actuator assembly (7) includes a housing (3), a crank slider mechanism and a disc spring (13). The crank slider mechanism includes a crank (5) and a connecting rod (12). The crank (5) is provided with an involute internal spline, which cooperates with the involute external spline. The crank slider mechanism is arranged inside the housing (3), the disc spring (13) is arranged on the upper side inside the housing (3), the lower end of the active locking hook (4) is stuck in the disc spring (13), and is connected to the connecting rod (12), the crank (5) drives the connecting rod (12) to move, and combined with the housing (3), the active locking hook (4) moves in the vertical direction, synchronously compressing the disc spring (13), and the locking holding force is provided by the deformation of the disc spring (13).

2. The ultrasonic motor driven space locking mechanism according to claim 1, characterized in that: The passive locking hook (14) is a structural component made of high-strength titanium alloy.

3. The ultrasonic motor driven space locking mechanism according to claim 1, characterized in that: The three-stage planetary reducer (2) comprises a sun gear (8), a first-stage planet (9), a second-stage planet (10) and a third-stage planet (11); the ultrasonic motor (1) drives the first-stage planet (9), the second-stage planet (10) and the third-stage planet (11) via the sun gear (8); the planet carrier of the third-stage planet (11) is provided with an involute external spline; the crank (5) cooperates with the external spline of the third-stage planet (11) to work.

4. The ultrasonic motor driven space locking mechanism according to claim 1, characterized in that: When locking, the active locking hook (4) moves downward in the vertical direction, pulling the passive locking hook (14) to complete the locking function.

5. The ultrasonic motor driven space locking mechanism according to claim 1, characterized in that: The internal spline rotates, and the active locking hook (4) at the end of the crank slider mechanism reciprocates along a certain range, completing the locking function of the passive end and compressing the disc spring (13) at the same time, so that the locking force gradually increases during the locking process.

6. The ultrasonic motor driven space locking mechanism according to claim 1, characterized in that: At the position where the locking is completed, the force generated by the compression of the disc spring (13) is the designed locking retention force, which is also the position where the crank (5) passes the dead point, thus realizing the self-locking function of the mechanism.

7. The ultrasonic motor driven space locking mechanism according to claim 1, characterized in that: The passive locking hook (14) is provided with a fillet R5 at a stress concentration location.

8. The ultrasonic motor driven space locking mechanism according to claim 1, characterized in that: The disc spring (13) consists of four pieces.

9. The ultrasonic motor driven space locking mechanism according to claim 1, characterized in that: The disc spring (13) is sleeved on the outside of the cylindrical section of the active locking hook (4) and fixed in the axial direction by two nuts. The disc spring (13) is made of 60Si2MnA high-strength spring steel.

10. The ultrasonic motor driven space locking mechanism according to claim 1, characterized in that: The aircraft is a spacecraft.

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