High-precision and high-reliability driving shafting device for space and calibration method

Abstract

The invention discloses a high-precision and high-reliability driving shaft system device for space and a calibration method. The device sequentially comprises a supporting bearing assembly, a sensor assembly, a speed reducer and a driving motor from right to left. A speed reducer is installed between the supporting bearing assembly and the driving motor, and the low-speed and high-torque output characteristic can be achieved. The sensor assembly is highly integrated in a structural part and is installed at the output end of the speed reducer. According to the invention, the self-adaptive adjustment of the pretightening force in the shaft system can be realized, and the device can be used in both ground and space environments; meanwhile, the linear Hall and the switch Hall are combined and are highly integrated in a driving shaft system structural part, the product space is not additionally occupied, and the envelope size of a driving shaft system is reduced; and thirdly, implementation is convenient, the position detection precision of the sensor assembly can be further improved through the calibration device, the calibration device has the ground calibration function and the on-orbit calibration function, and therefore accurate control is conducted.

Description

Technical Field

[0001] The invention belongs to the field of satellite actuators, and in particular relates to a high-precision and high-reliability driving shaft system device for space and a calibration method. Background Art

[0002] The drive shaft system is an actuator that is mainly used to drive the space payload to rotate together to achieve the requirements of large field of view coverage. With the increasing number of satellites in orbit in my country and the continuous deepening of space attack and defense technology, the demand for high-precision stable control, long-life and high-reliability service of space vehicles is becoming increasingly strong. As a core component, the low-speed shaft system for space is not only required to have a simple structure, high rotation accuracy, and the ability to withstand axial and radial loads at the same time, but also to output torque. The high precision of the space low-speed shaft system mainly depends on factors such as the rotation accuracy of the shaft system, position detection accuracy, external calibration accuracy, and algorithm compensation accuracy.

[0003] The low-speed shaft support bearing assembly for space generally adopts a pair of angular contact ball bearings installed back to back to provide a bearing configuration with higher rigidity. The bearings must be preloaded with a certain axial load under normal working conditions. The main purpose is to improve the rotation accuracy of the bearings, reduce the sliding of the rolling elements under high speed, improve the bearing rigidity, reduce the axial and radial movement of the support, reduce noise and increase the service life of the bearings. The greater the preload of the bearing, the greater the friction, the greater the driving force required by the motor, and the insufficient driving torque of the motor may cause the shaft system to get stuck; on the contrary, the bearing preload is reduced, the friction becomes smaller, the driving force required by the motor also becomes smaller, but the axial stiffness of the bearing becomes smaller and the movement is large. Therefore, it is particularly important to select the appropriate preload force to apply.

[0004] The common practice of applying preload is to adjust the height difference between the inner and outer spacers of the bearing to achieve the positioning preload of the bearing. However, after entering the space orbit, the shaft system is in a weightless state, and the shaft system preload changes compared to the ground. After the ground undergoes mechanical and thermal environment tests, the bearing preload also changes. In addition, after the shaft system has been running in orbit for a long time, especially in the middle and late stages of the bearing life, the bearing will inevitably produce friction and wear, and indicators such as the bearing protrusion will change, and the preload will also change accordingly. However, due to the particularity of the use environment, the preload of the shaft system cannot be adjusted in the space environment. Therefore, a drive shaft system that can adaptively adjust the preload of the space shaft system is required.

[0005] In addition, in order to ensure the position control accuracy of the shaft system, it is generally necessary to install traditional position sensors such as resolvers, inductive synchronizers, or optical encoders. These sensors are generally large in size and relatively heavy in weight, and their accuracy is highly correlated with their size; while relatively small and light sensors cannot achieve very high accuracy. Therefore, a small-volume, highly integrated position sensor and its high-precision calibration method are needed to achieve high-precision and high-reliability drive shaft systems. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes a high-precision and high-reliability drive shaft system device and a calibration method for space use.

[0007] The technical solution of the present invention is as follows:

[0008] A high-precision and high-reliability drive shaft system device for space and a calibration method, wherein the high-precision and high-reliability drive shaft system device for space includes a support bearing assembly, a sensor assembly, a reducer, and a drive motor from right to left;

[0009] A reducer is installed between the support bearing assembly and the drive motor to achieve low-speed and high-torque output characteristics;

[0010] The sensor assembly is highly integrated in the structural member and installed at the output end of the reducer.

[0011] The support bearing assembly includes a labyrinth seal gland, a spacer ring, a bearing seat, a bearing, a core shaft, a disc spring, and a locking nut;

[0012] The bearing comprises a lower bearing and an upper bearing, and the lower bearing and the upper bearing are installed back-to-back to increase the bearing span and improve the bearing capacity of the shaft system component; the inner ring of the bearing is precisely matched with the core shaft as the rotating part, and the outer ring of the bearing is precisely matched with the bearing seat as the stationary part;

[0013] The end of the mandrel is fixed axially to the shaft system by a locking nut to prevent the bearing from axial loosening and unloading;

[0014] The spacer includes an outer spacer and an inner spacer, which are installed between the upper bearing and the lower bearing; the bearing is axially preloaded by adjusting the height difference of the spacer;

[0015] The disc spring is installed between the root end face of the mandrel and the lower bearing, which can effectively prevent the active section from over-impacting load;

[0016] The labyrinth gland is installed on the outer end surface of the bearing seat to axially position the outer ring of the bearing.

[0017] The outer spacer ring is made of intelligent piezoelectric material, and stress sheets are pasted at four positions on the inner surface as preload force measurement elements. The average value of the measurement results of the multiple stress sheets is transmitted to the information processing unit for analysis and processing, and the magnitude of the axial force of the shaft system is monitored and fed back in real time. The axial force of the shaft system is the preload force.

[0018] The preload force should be calibrated before measurement to check whether the error between the actual measured value of the stress sheet and the actual applied preload force is within a reasonable range. The specific method is: first, according to the sum of the protrusions of the lower bearing and the upper bearing under the specified preload, grind the inner spacer to match the height difference between the outer spacer and the inner spacer, and then measure the friction force when the outer spacer and the bearing slide relative to each other; then, based on the friction force and the friction coefficient of the outer spacer bearing end face, indirectly derive the difference between the actual preload force applied to the bearing and the preload force measured by the stress sheet, and the difference will meet the requirements within the allowable range.

[0019] The sensor assembly includes a linear Hall, a switch Hall, a magnetic ring and a setting device, and is highly integrated, lightweight, high-precision and reliable;

[0020] The magnetic field distribution of the magnetic ring in space is complex, and the magnetic field vector is a space vector. However, in the present invention, only the radial space magnetic field is an effective detection magnetic field.

[0021] The setting device sets the magnetic field distribution of the magnetic ring in space, improves the strength and sinusoidality of the radial magnetic field, effectively reduces the invalid tangential magnetic field component, and improves the detection accuracy of the position sensor.

[0022] The linear Hall is arranged in four orthogonal paths, evenly spaced at 90 degree intervals. By differentiating the linear Hall signal, the signal's anti-interference and installation error compensation can be ensured.

[0023] The switch Hall is multi-channel and installed at other angles in space, which can calibrate the position error of linear Hall detection on-orbit and compensate it on-orbit through the information processing unit;

[0024] The information processing unit changes according to the change of the preload force. Once the preload force exceeds the design value range, the power supply voltage of the piezoelectric material will be adjusted to change the height of the outer spacer, thereby changing the height difference of the spacer and adjusting the size of the preload force.

[0025] The calibration device matched with the high-precision and high-reliability driving shaft system device for space is a ground calibration device; the ground calibration device includes a high-precision calibration sensor, a connecting bracket, a supporting bracket and the high-precision and high-reliability driving shaft system device for space from left to right; the accuracy of the high-precision calibration sensor is better than 1″;

[0026] The high-precision and high-reliability driving shaft system device for space and the high-precision calibration sensor are rigidly connected, and the 360° position accuracy of the high-precision and high-reliability driving shaft system device for space can be calibrated, and the position error can be sent to the information processing unit for error compensation.

[0027] The calibration device matched with the high-precision and high-reliability driving shaft system device for space is an on-orbit calibration device, which includes the high-precision and high-reliability driving shaft system device for space and a star sensor; the star sensor is an essential angle measurement equipment for satellites, and cooperates with the switch Hall to complete the on-orbit calibration.

[0028] The specific steps of the calibration method of the space high-precision and high-reliability drive shaft system device and the ground calibration are as follows:

[0029] S1. Install a high-precision and high-reliability drive shaft system device on one side of the support bracket, and install a high-precision calibration sensor on the other side of the support bracket;

[0030] S2. Using the information processing unit to read the preload value of the supporting bearing assembly in the current state is small. If there is a deviation from the design value, the height of the outer spacer is adjusted so that the preload force meets the design value requirement;

[0031] S3. Use the information processing unit to rotate the high-precision and high-reliability drive shaft system device according to the set rotation step and stabilize it in the current position, compare the angle value fed back by the high-precision and high-reliability drive shaft system device itself with the feedback value of the high-precision calibration sensor on the ground, correct the difference, perform curve fitting on all the correction points after one rotation, and load it into the information processing unit as a compensation curve for improving accuracy.

[0032] The specific steps of the calibration method of the high-precision and high-reliability drive shaft system device for space on-orbit calibration are as follows:

[0033] S1, the high-precision and high-reliability drive shaft system device for space is rotated according to the specified step length, and the feedback value of the sensor component is compared and corrected with the detection value of the star sensor after stabilization;

[0034] S2. All correction points in one circle are subjected to curve fitting and loaded into the information processing unit to perform error compensation on the position of the entire circle to improve the accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 is a schematic diagram of a support bearing assembly in an embodiment of the present invention;

[0037] Figure 2 is an outer spacer ring appearance diagram in an embodiment of the present invention;

[0038] Figure 3A schematic diagram of an application flow in an embodiment of the present invention;

[0039] Figure 4 Schematic diagram of a space drive shaft system in an embodiment of the present invention;

[0040] Figure 5 Schematic diagram of comparison of radial tangential air gap magnetic field curves before and after magnetic field setting in an embodiment of the present invention;

[0041] Figure 6 It is a ground calibration device for a high-precision and high-reliability drive shaft system device for space in an embodiment of the present invention.

[0042] In the figure: 1 is a labyrinth seal gland; 2 is an outer spacer; 3 is a bearing seat; 4 is a lower bearing; 5 is a core shaft; 6 is a disc spring; 7 is an inner spacer; 8 is an upper bearing; 9 is a locking nut; 10 is a supporting bearing assembly; 11 is a sensor assembly; 12 is a reducer; 13 is a driving motor; 14 is a high-precision calibration sensor; 15 is a connecting bracket; 16 is a supporting bracket; 17 is a stress sheet.

[0043] Specific implementation methods

[0044] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0045] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0046] The specific technologies are:

[0047] like Figure 4 As shown, a high-precision and high-reliability drive shaft system device for space and a calibration method, wherein the high-precision and high-reliability drive shaft system device for space includes a support bearing assembly 10, a sensor assembly 11, a reducer 12, and a drive motor 13 from right to left;

[0048] A reducer 12 is installed between the support bearing assembly 10 and the drive motor 13 to achieve low-speed and high-torque output characteristics;

[0049] The sensor assembly 11 is highly integrated in the structure and installed at the output end of the reducer 12 .

[0050] like Figure 1 As shown, the support bearing assembly 10 includes a labyrinth seal gland 1, a spacer ring, a bearing seat 3, a bearing, a core shaft 5, a disc spring 6, and a locking nut 9;

[0051] The bearing comprises a lower bearing 4 and an upper bearing 8, and the lower bearing 4 and the upper bearing 8 are installed back-to-back to increase the bearing span and improve the bearing capacity of the shaft system assembly; the inner ring of the bearing is precisely matched with the core shaft 5 as the rotating part, and the outer ring of the bearing is precisely matched with the bearing seat 3 as the stationary part;

[0052] The end of the mandrel 5 is axially fixed to the shaft system by a locking nut 9 to prevent the bearing from axially loosening and unloading;

[0053] The spacer includes an outer spacer 2 and an inner spacer 7, which are installed between the upper bearing 8 and the lower bearing 4; the bearing is axially preloaded by adjusting the height difference of the spacer;

[0054] The disc spring 6 is installed between the root end surface of the core shaft 5 and the lower bearing 4, which can effectively prevent the active section from over-impact load;

[0055] The labyrinth gland 1 is installed on the outer end surface of the bearing seat 3 to axially position the outer ring of the bearing.

[0056] like Figure 2 As shown, the outer spacer 2 is made of intelligent piezoelectric material, and stress sheets 17 are pasted at four positions on the inner surface as preload force measuring elements;

[0057] like Figure 3 As shown, the average value of the measurement results of the plurality of stress sheets 17 is taken and transmitted to the information processing unit for analysis and processing, and the magnitude of the axial force of the shaft system is monitored and fed back in real time, and the axial force of the shaft system is the preload force.

[0058] The preload should be calibrated before measurement to check whether the error between the measured value of the stress sheet 17 and the actual applied preload is within a reasonable range. The specific method is: first, according to the sum of the protrusions of the lower bearing 4 and the upper bearing 8 under the specified preload, grind the inner spacer 7 to match the height difference between the outer spacer 2 and the inner spacer 7, and then measure the friction force when the outer spacer 2 and the bearing slide relative to each other; then, according to the friction force and the friction coefficient of the bearing end face of the outer spacer 2, indirectly obtain the difference between the actual preload applied by the bearing and the preload measured by the stress sheet 17, and the difference will meet the requirements within the allowable range.

[0059] The sensor assembly 11 includes a linear Hall, a switch Hall, a magnetic ring and a setting device, and is highly integrated, lightweight, high-precision and reliable;

[0060] like Figure 5As shown in a, the magnetic field distribution of the magnetic ring in space is complex, and the magnetic field vector is a space vector, but in the present invention, only the radial space magnetic field is an effective detection magnetic field;

[0061] like Figure 5 As shown in b, the adjustment device adjusts the magnetic field distribution of the magnetic ring in space, improves the strength and sinusoidality of the radial magnetic field, effectively reduces the invalid tangential magnetic field component, and improves the detection accuracy of the position sensor.

[0062] The linear Hall is arranged in four orthogonal paths, evenly spaced at 90 degree intervals. By differentiating the linear Hall signal, the signal's anti-interference and installation error compensation can be ensured.

[0063] The switch Hall is multi-channel and installed at other angles in space, which can calibrate the position error of linear Hall detection on-orbit and compensate it on-orbit through the information processing unit;

[0064] The information processing unit changes according to the change of the preload force. Once the preload force exceeds the design value range, the power supply voltage of the piezoelectric material will be adjusted to change the height of the outer spacer 2, thereby changing the height difference of the spacer and adjusting the size of the preload force.

[0065] like Figure 6 As shown, the calibration device matched with the high-precision and high-reliability driving shaft system device for space is a ground calibration device; the ground calibration device includes a high-precision calibration sensor 14, a connecting bracket 14, a supporting bracket 16 and the high-precision and high-reliability driving shaft system device for space from left to right; the accuracy of the high-precision calibration sensor is better than 1″;

[0066] The high-precision and high-reliability driving shaft system device for space and the high-precision calibration sensor 14 are rigidly connected, and the high-precision and high-reliability driving shaft system device for space can be calibrated for a 360° position accuracy, and the position error can be sent to the information processing unit for error compensation.

[0067] The calibration device matched with the high-precision and high-reliability driving shaft system device for space is an on-orbit calibration device, which includes the high-precision and high-reliability driving shaft system device for space and a star sensor; the star sensor is an essential angle measurement equipment for satellites, and cooperates with the switch Hall to complete the on-orbit calibration.

[0068] The specific steps of the calibration method of the space high-precision and high-reliability drive shaft system device and the ground calibration are as follows:

[0069] S1. Install a high-precision and high-reliability drive shaft system device on one side of the support bracket 16, and install a high-precision calibration sensor 14 on the other side of the support bracket 16;

[0070] S2, using the information processing unit to read the preload value of the support bearing assembly 10 in the current state is small. If there is a deviation from the design value, adjust the height of the outer spacer 2 so that the preload force meets the design value requirement;

[0071] S3. Use the information processing unit to rotate the high-precision and high-reliability drive shaft system device according to the set rotation step and stabilize it in the current position, compare the angle value fed back by the high-precision and high-reliability drive shaft system device itself and the feedback value of the high-precision calibration sensor 14 on the ground, correct the difference, perform curve fitting on all the correction points after one rotation, and load it into the information processing unit as a compensation curve for improving accuracy.

[0072] The specific steps of the calibration method of the high-precision and high-reliability drive shaft system device for space on-orbit calibration are as follows:

[0073] S1, the high-precision and high-reliability driving shaft system device for space is rotated according to the specified step length, and the feedback value of the sensor component 11 is compared and corrected with the detection value of the star sensor after stabilization;

[0074] S2. All correction points in one circle are subjected to curve fitting and loaded into the information processing unit to perform error compensation on the position of the entire circle to improve the accuracy.

[0075] The embodiments of the present invention described above are only used to help explain the present invention. These embodiments are selected and specifically described in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification, which all belong to the protection scope of the present invention.

Claims

1. A high-precision and high-reliability drive shaft system device for space use, characterized in that: From right to left, it includes a support bearing assembly (10), a sensor assembly (11), a reducer (12), and a drive motor (13); A reducer (12) is installed between the support bearing assembly (10) and the drive motor (13), so as to achieve low-speed and high-torque output characteristics; The sensor assembly (11) is highly integrated in the structural component and installed at the output end of the reducer (12).

2. A high-precision and high-reliability drive shaft system device for space use as claimed in claim 1, characterized in that: The support bearing assembly (10) comprises a labyrinth seal gland (1), a spacer ring, a bearing seat (3), a bearing, a core shaft (5), a disc spring (6), and a locking nut (9); The bearing comprises a lower bearing (4) and an upper bearing (8), wherein the lower bearing (4) and the upper bearing (8) are installed back-to-back to increase the bearing span and improve the bearing capacity of the shaft system component; the inner ring of the bearing, as a rotating part, is precisely matched with the core shaft (5), and the outer ring of the bearing, as a stationary part, is precisely matched with the bearing seat (3); The end of the core shaft (5) is axially fixed to the shaft system by a locking nut (9) to prevent the bearing from axially loosening and unloading; The spacer comprises an outer spacer (2) and an inner spacer (7), which are installed between the upper bearing (8) and the lower bearing (4); the bearing is axially preloaded by adjusting the height difference of the spacer; The disc spring (6) is installed between the root end surface of the core shaft (5) and the lower bearing (4), and can effectively prevent the active section from being overloaded; The labyrinth gland (1) is mounted on the outer end surface of the bearing seat (3) to axially position the outer ring of the bearing; Stress sheets (17) are pasted at four positions on the inner surface of the outer spacer (2) as preload force measuring elements.

3. A high-precision and high-reliability drive shaft system device for space use as claimed in claim 1, characterized in that: The sensor component (11) comprises a linear Hall, a switch Hall, a magnetic ring and a setting device; the magnetic field distribution of the magnetic ring in space is complex, and the magnetic field vector is a space vector.

4. A high-precision and high-reliability drive shaft system device for space use as claimed in claim 3, characterized in that: The setting device sets the magnetic field distribution of the magnetic ring in space, improves the strength and sinusoidality of the radial magnetic field, effectively reduces the invalid tangential magnetic field component, and improves the detection accuracy of the position sensor.

5. A high-precision and high-reliability drive shaft system device for space use as claimed in claim 3, characterized in that: The linear Hall is arranged in four orthogonal paths, evenly spaced at 90 degree intervals. By differentiating the linear Hall signal, the signal's anti-interference and installation error compensation can be ensured.

6. A high-precision and high-reliability drive shaft system device for space use as claimed in claim 3, characterized in that: The switch Hall is multi-channel and installed at other angles in space, which can perform on-track calibration and on-track compensation for the position error of linear Hall detection.

7. A high-precision and high-reliability drive shaft system device for space use as claimed in claim 1, characterized in that: The matching calibration device is a ground calibration device; the ground calibration device comprises, from left to right, a high-precision calibration sensor (14), a connecting bracket (15), a supporting bracket (16) and the high-precision and high-reliability driving shaft system device for space; the accuracy of the high-precision calibration sensor (14) is better than 1″; The high-precision and high-reliability space drive shaft system device and the high-precision calibration sensor (14) are rigidly connected, and the position accuracy of the high-precision and high-reliability space drive shaft system device can be calibrated for 360°, and the position error is sent to the information processing unit for error compensation.

8. A high-precision and high-reliability drive shaft system device for space use as claimed in claim 1, characterized in that: The matching calibration device is an on-orbit calibration device, which includes a high-precision and high-reliability drive shaft system device and a star sensor for space; the star sensor is an essential angle measurement device for satellites, and cooperates with the switch Hall to complete the on-orbit calibration.

9. A calibration method for a high-precision and high-reliability space drive shaft system device as claimed in claim 7, characterized in that: The specific steps are as follows: S1. Install a high-precision and high-reliability space drive shaft system device on one side of the support bracket (16), and install a high-precision calibration sensor (14) on the other side of the support bracket (16); S2, using the information processing unit to read the preload value of the support bearing assembly (10) in the current state. If it deviates from the design value, adjust the height of the outer spacer (2) so that the preload force meets the design value requirement; S3. Using the information processing unit, the high-precision and high-reliability drive shaft system device is rotated according to the set rotation step and stabilized at the current position. The angle value fed back by the high-precision and high-reliability drive shaft system device itself is compared with the feedback value of the ground high-precision calibration sensor (14), and the difference is corrected. After one rotation, curve fitting is performed on all the correction points, and the curve is loaded into the information processing unit as a compensation curve for improving accuracy.

10. A calibration method for a high-precision and high-reliability space drive shaft system device as claimed in claim 8, characterized in that: The specific steps are as follows: S1, the high-precision and high-reliability driving shaft system device for space is rotated according to the specified step length, and the feedback value of the sensor component (11) is compared and corrected with the detection value of the star sensor after stabilization; S2. All correction points in one circle are subjected to curve fitting and loaded into the information processing unit to perform error compensation on the position of the entire circle to improve the accuracy.

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