Torque actuator

Abstract

A torque actuator disclosed by the present invention comprises an elastic rod, a torque sensor and a motor, the torque sensor comprises a torque receiving end, a plurality of elastic blades and a torque output end, the elastic blades are provided with torque sensitive elements, and the elastic blades are arranged along the circumferential direction. The torque receiving end is connected with the motor through a coupler and transmits torque output by the motor to the elastic blades, the torque output end is connected with the elastic blades to transmit the torque to the elastic rod, and the elastic rod is connected with an object with torque to be adjusted. When a torque to-be-adjusted object is a sub-mirror of an astronomical optical telescope, the torque can be measured in real time and the surface shape of the mirror surface can be corrected while the torque is applied to the sub-mirror; the torque actuator is simple in structure, clear in principle, easy to manufacture and good in reliability and stability.

Description

Technical Field

[0001] The present invention relates to the design of an innovative torque actuator for precisely applying a torque, particularly suitable for applying a torque on a passive floating support structure of a precision optical mirror to achieve real-time correction of the surface shape. Background Art

[0002] With the development of astronomical optical telescope technology and the increase in the telescope aperture, the manufacturing cost of a single mirror is high, the process is complex, and the mirror polishing and opto-mechanical assembly costs are expensive. Nowadays, the primary mirrors of large-aperture telescopes mostly adopt the technology of segmented mirrors, involving a large number of segmented sub-mirrors. Figure 1 The figure shows a schematic diagram of the sub-mirror support structure of a common passive floating support structure. After optical processing, a large number of sub-mirrors often have low-frequency residual surface shape errors, and during observation, environmental factors will also cause surface shape errors of the sub-mirrors. Therefore, a torque actuator is used to apply a torque on the passive floating support structure of a precision optical mirror to achieve real-time correction of the mirror surface shape, so that each sub-mirror can achieve confocal or co-phasing. Therefore, a high-precision torque actuator is one of the key devices for realizing mirror segmentation. These actuators can perform real-time precise control of the mirror surface shape to adapt to various changes during the observation process, such as the influence of gravity, temperature, etc. on the mirror shape. By using modern sensing and control technologies, the torque actuators of the segmented sub-mirrors can ensure the optical performance of the telescope.

[0003] Many foreign large telescopes (such as Keck, TMT, and E-ELT) use torque actuators to correct the surface shape of the sub-mirrors in real time, but the ways to achieve this function are different. Keck adjusts the force condition on the support rod of the tripod by manually rotating the adjustment knob, and these knobs are connected to the elastic blades fixed on the tripod, by changing the pre-tightening force; TMT uses a linear motor to generate a linear displacement, and this displacement is converted into a torque through the elastic blade, and then acts on the pivot of the tripod to adjust the distribution of the support force and thus correct the mirror surface shape; E-ELT also realizes torque loading by the same principle. Summary of the Invention

[0004] Aiming at the above problems existing in the prior art, the present invention provides a torque actuator. This torque actuator directly uses a motor to generate a torque, and its structure is different from the existing torque actuators, but it can produce the same technical effects as the existing technical solutions.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A torque actuator includes an elastic rod, a torque sensor, and a motor. The torque sensor includes a torque receiving end, elastic vanes, and a torque output end. A torque sensitive element is provided on the elastic vanes. A plurality of elastic vanes are arranged circumferentially, and the central axes of the plurality of elastic vanes are consistent with the extending direction of the elastic rod. The torque receiving end is connected to the motor through a coupling and transmits the torque output by the motor to the elastic vanes. The torque output end transmits the torque to the elastic rod by connecting with the elastic vanes. The elastic rod is connected to the object to be torque-adjusted.

[0007] Further, the torque receiving end includes a connecting shaft and a receiving end connecting plate. The torque output end includes an output end connecting plate. One end of the connecting shaft is key-connected to the coupling, and the other end is fixed to the receiving end connecting plate. One end of the elastic rod is connected to the object to be torque-adjusted, and the other end is fixed to the output end connecting plate. A plurality of elastic vanes are fixedly connected between the receiving end connecting plate and the output end connecting plate independently of each other.

[0008] Further, the torque receiving end includes a connecting shaft and a receiving end connecting plate. The torque output end includes an output end connecting plate. One end of the connecting shaft is key-connected to the coupling, and the other end is fixed to the receiving end connecting plate. One end of the elastic rod is connected to the object to be torque-adjusted, and the other end is fixed to the output end connecting plate. A squirrel-cage cylinder is fixedly installed between the receiving end connecting plate and the output end connecting plate. A plurality of through holes are provided on the side surface of the squirrel-cage cylinder circumferentially, and adjacent through holes are separated by the elastic vanes.

[0009] Further, the torque receiving end includes a connecting shaft. The torque output end includes a sensor sleeve and an output end connecting plate. One end of the connecting shaft is key-connected to the coupling, and the other end is a free end without a connection relationship. The inner sides of a plurality of elastic vanes are fixedly installed on the main body of the connecting shaft. The outer sides of the elastic vanes are fixedly connected to the sensor sleeve. One end of the sensor sleeve is fixedly connected to the output end connecting plate, and the other end is a free end without a connection relationship. One end of the elastic rod is connected to the object to be torque-adjusted, and the other end is fixed to the output end connecting plate.

[0010] Further, the torque receiving end includes a connecting shaft. The torque output end includes an elastic connecting piece and an output end connecting plate. One end of the connecting shaft is key-connected to the coupling, and the other end is a free end without a connection relationship. The inner sides of a plurality of elastic vanes are fixedly installed on the main body of the connecting shaft. The outer sides of the elastic vanes are connected and fastened through an elastic vane connecting plate. The elastic vane connecting plate is connected to the output end connecting plate through an elastic connecting piece. One end of the elastic rod is connected to the object to be torque-adjusted, and the other end is fixed to the output end connecting plate.

[0011] Further, the torque receiving end includes a receiving end connecting shaft, a spring, and a sensor sleeve, and the torque output end includes an output end connecting shaft. One end of the receiving end connecting shaft is key-connected to the coupling, and the other end is a free end without a connection relationship. The inner end of the spring is connected to the receiving end connecting shaft, and the outer end of the spring is connected to the sensor sleeve. The inner sides of a plurality of elastic vanes are fixedly installed on the main body of the output end connecting shaft, and the outer sides of the elastic vanes are fixedly connected to the sensor sleeve. One end of the output end connecting shaft is fixedly connected to one end of the elastic rod, and the other end is a free end without a connection relationship. The other end of the elastic rod is connected to the object to be torque-adjusted.

[0012] Further, the torque receiving end includes a receiving end connecting shaft, and the torque output end includes an output end connecting shaft, a sensor sleeve, and a spring. One end of the receiving end connecting shaft is key-connected to the coupling, and the other end is a free end without a connection relationship. The inner sides of a plurality of elastic vanes are fixedly installed on the main body of the receiving end connecting shaft, and the outer sides of the elastic vanes are fixedly connected to the sensor sleeve. One end of the output end connecting shaft is fixedly connected to one end of the elastic rod, and the other end is a free end without a connection relationship. The other end of the elastic rod is connected to the object to be torque-adjusted. The inner end of the spring is connected to the output end connecting shaft, and the outer end of the spring is connected to the sensor sleeve.

[0013] Further, the elastic rod includes a connecting member, a universal joint, and an elastic thin rod. The two ends of the elastic thin rod are respectively connected to the connecting member through the universal joint.

[0014] Further, the object to be torque-adjusted is the secondary mirror of an astronomical optical telescope, and the torque actuator is used to apply torque at the pivot of the secondary mirror floating support structure to adjust the surface shape of the secondary mirror of the astronomical optical telescope.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] The present invention provides a torque actuator, which can be used for the active support of the secondary mirror of an astronomical optical telescope, and can directly apply torque at the pivot of the secondary mirror floating support structure to adjust the surface shape. The torque sensor of the torque actuator can measure the torque in real time, will not contract in length to interfere with the object to which the torque is applied, and has the advantages of simple structure and simple process. Description of the Drawings

[0017] Figure 1 is a schematic diagram of a typical passive floating secondary mirror support system.

[0018] Figure 2 is a working schematic diagram of the torque actuator in Embodiment 1.

[0019] Figure 3 is an exploded view of the torque actuator in Embodiment 1.

[0020] Figure 4 It is a 3D schematic diagram of the torque sensor in Embodiment 1.

[0021] Figure 5 It is an exploded view of the torque sensor in Embodiment 1.

[0022] Figure 6 It is a working schematic diagram of the torque actuator in Embodiment 2.

[0023] Figure 7 It is an exploded view of the torque actuator in Embodiment 2.

[0024] Figure 8 It is a 3D schematic diagram of the torque sensor in Embodiment 2.

[0025] Figure 9 It is an optimized solution for the elastic thin rod.

[0026] Figure 10 It is a working schematic diagram of the torque actuator in Embodiment 3.

[0027] Figure 11 It is an exploded view of the torque actuator in Embodiment 3.

[0028] Figure 12 It is a schematic diagram of the cross-assembly method of the elastic blades.

[0029] Figure 13 It is a 3D schematic diagram of the torque sensor in Embodiment 3.

[0030] Figure 14 It is an internal schematic diagram of the torque sensor in Embodiment 3.

[0031] Figure 15 It is a working schematic diagram of the torque actuator in Embodiment 4.

[0032] Figure 16 It is an exploded view of the torque actuator in Embodiment 4.

[0033] Figure 17 It is a 3D schematic diagram of the torque sensor in Embodiment 4.

[0034] Figure 18 It is a working schematic diagram of the torque actuator in Embodiment 5.

[0035] Figure 19 It is an exploded view of the torque actuator in Embodiment 5.

[0036] Figure 20 It is an internal schematic diagram of the torque sensor in Embodiment 5.

[0037] Figure 21 It is a working schematic diagram of the torque actuator in Embodiment 6.

[0038] Figure 22 It is an exploded view of the torque actuator of Embodiment VI.

[0039] Figure 23 It is an internal schematic diagram of the torque sensor in Embodiment VI.

[0040] Markings in the figure: 1. Sub-mirror, 2. Support thin rod, 3. Floating support tripod, 4. Elastic thin rod (I), 5. Connecting plate, 6. Elastic vane (I), 7. Torque sensitive element, 8. Nut (I), 9. Short connecting shaft, 10. Rigid coupling, 11. Set screw, 12. Machine base, 13. Screw (I), 14. Motor, 15. Nut (II), 16. Key, 17. Connector (I), 18. Universal joint, 19. Elastic thin rod (II), 20. Connector (II), 21. Connecting plate with threaded hole, 22. Squirrel-cage cylinder, 23. Screw (II), 24. Sensor sleeve, 25. Elastic vane (II), 26. Nut (III), 27. Connecting shaft with cross slot, 28. Elastic vane connecting plate, 29. Elastic connecting piece, 30. Square connecting plate, 31. Screw (III), 32. Sensor long sleeve, 33. Cross slot connecting shaft (I), 34. Cross slot connecting shaft (II), 35. Spring, 36. Nut (IV), 37. Cross slot connecting shaft (III), 38. Cross slot connecting shaft (IV), 39. Support pad. Detailed implementation manners

[0041] The present invention will be further described in detail below with reference to the accompanying drawings.

[0042] The present invention provides a torque actuator, which mainly includes an elastic rod, a torque sensor, and a motor. The torque sensor includes a torque receiving end, elastic blades, and a torque output end. Torque sensitive elements are provided on the elastic blades. A number of elastic blades are arranged circumferentially, for example, 6 elastic blades are evenly arranged circumferentially, and the central axes of the number of elastic blades are consistent with the extending direction of the elastic rod. The torque receiving end is connected to the motor through a coupling and transmits the torque output by the motor to the elastic blades. The torque output end transmits the torque to the elastic rod by connecting with the elastic blades, and the elastic rod is connected to the object whose torque is to be adjusted. When the elastic blades are deformed, the torque sensitive elements will generate a measurable physical quantity, and then the magnitude of the torque can be obtained, that is, the mechanical torque is converted into an electrical signal for measurement. The torque sensitive elements can be strain gauges. The torque is measured by pasting strain gauges on the elastic blades. When the elastic blades are subjected to torque, the strain gauges will generate resistance changes due to the deformation of the elastic blades, thereby measuring the torque. This torque actuator directly uses a motor to generate torque, which is different from existing torque actuators, but can produce the same effect as the prior art solutions. When this torque actuator is used for the active support of the secondary mirror of an astronomical optical telescope, torque can be directly applied at the pivot of the floating support structure of the secondary mirror to adjust the surface shape. The torque sensor of this torque actuator can measure the torque in real time and has the advantages of simple structure and simple process. Taking the secondary mirror of an astronomical optical telescope as the object whose torque is to be adjusted, the structure of the present invention will be described in detail below.

[0043] Embodiment 1

[0044] Refer to Figures 2 to 5 , the secondary mirror 1 is supported on the floating support tripod 3 by the support thin rod 2, and the support thin rod 2 supports the secondary mirror 1 through the support pad 39. Then, the torque actuator of the present invention is proposed, which includes an elastic thin rod (1) 4, a torque sensor, a coupling 10, a machine base 12, and a motor 14. The torque sensor includes a connecting plate 5, elastic blades (1) 6, and torque sensitive elements 7 provided on the elastic blades (1) 6. The spatial positions of the elastic thin rod (1) 4, the torque sensor, the coupling 10, and the motor transmission shaft are coaxial. One end of the elastic thin rod (1) 4 is connected to the floating support tripod 3, and the other end is connected and fastened to the torque sensor through a nut (2) 15. The other end of the torque sensor is connected to the short connecting shaft 9 through a nut (1) 8, and the other end of the short connecting shaft 9 is connected to the motor transmission shaft through the coupling 10. The short connecting shaft 9 and the coupling 10 can be connected by a key 16; a set screw 11 is used to connect between the motor transmission shaft and the coupling 10, and finally the motor 14 is fixed to the machine base 12 by a screw (1) 13.

[0045] In this embodiment, the two ends of the torque sensor are connecting plates 5, and a number of grooves are evenly distributed on the circumference of the connecting plates 5; a number of independent elastic blades (I) 6 are fixedly connected to the corresponding grooves between the two connecting plates 5. A torque sensitive element 7 is pasted on each elastic blade (I) 6.

[0046] Embodiment II

[0047] See Figures 6 - 8 . The structure of the torque actuator in this embodiment is basically the same as that of Embodiment I, and the main difference lies in the manufacturing method of the elastic blades. Specifically, in this embodiment, a cage-type cylinder 22 made of an integral elastic material is used. A number of threaded holes are provided at both ends of the cage-type cylinder 22. The connecting plate 21 with threaded holes and the cage-type cylinder 22 are connected by screws (II) 23. A number of through holes are provided on the side of the cage-type cylinder 22 along the circumferential direction. After milling, the thin sheet separating adjacent through holes is the elastic blade (I) 6. Usually, the device used to apply torque often causes length contraction while applying torque, which is often harmful in the application of precision engineering. The following embodiments make further improvements to this problem. In Embodiments III to VI, there is no length contraction while applying torque.

[0048] Further improvement of the elastic rod, see Figure 9 , the elastic rod includes an elastic thin rod (II) 19, a universal joint 18, a connecting piece (I) 17, and a connecting piece (II) 20. The elastic thin rod (II) 19 is connected to the universal joint 18 through the threads at both ends, and the universal joint 18 is connected to the connecting piece (I) 17 and the connecting piece (II) respectively through threads. This elastic rod can better eliminate the forces and torques in other directions caused by the deformation of the elastic rod by using the universal joint. The elastic rod with this structure is adopted in this embodiment and the subsequent Embodiments III to VI.

[0049] Embodiment III

[0050] See Figures 10 to 14 . The improvement is mainly reflected in the torque sensor. The torque sensor in this embodiment mainly includes a connecting shaft 27 with a cross groove, a sensor sleeve 24, elastic blades (II) 25, and a connecting plate 21. Two perpendicular and intersecting elastic blades (II) 25 are placed inside the torque sensor and fixedly connected to the sensor sleeve 24. At the same time, the end faces of the elastic blades (II) 25 and the sensor sleeve 24 connected to the coupling 10 coincide. One end of the sensor sleeve 24 is fixedly connected to the connecting plate 21, and the other end is a free end with no connection relationship. The two elastic blades (II) 25 are embedded in a connecting shaft 27 with a cross groove. One end of the connecting shaft 27 with a cross groove is key-connected to the coupling, and the other end is a free end with no connection relationship. The elastic blades (II) 25 are fastened and limited by a nut (III) 26. A torque sensitive element 7 is pasted on each elastic blade (II) 25.

[0051] Example 4

[0052] See Figures 15 to 17 The improvement is mainly reflected in the torque sensor. The torque sensor in this embodiment mainly includes a connecting shaft 27 with a cross slot, an elastic blade (II) 25, an elastic blade connecting plate 28, and an elastic connecting piece 29. After the elastic blade (II) 25 and the connecting shaft 27 with a cross slot are fixed, the elastic blade connecting plate 28 is used to further connect and fasten the elastic blade (II) 25. The elastic connecting piece 29 covers the square connecting plate 30 and the elastic blade connecting plate 28, and the two are connected together by using screws (III) 31, thus forming a new torque sensor.

[0053] Example 5

[0054] See Figures 18 to 20 The improvement is mainly reflected in the torque sensor. The torque sensor in this embodiment mainly includes a cross slot connecting shaft (I) 33, a cross slot connecting shaft (II), an elastic blade (II) 25, and a spring 35. Two vertically crossed elastic blades (II) 25 and the spring 35 are placed in the sensor long sleeve 32. The two vertically crossed elastic blades (II) 25 are embedded on the cross slot connecting shaft (I) 33, and the spring 35 is embedded on the cross slot connecting shaft (II) 34. The cross slot connecting shaft (I) 33 is connected to the universal joint 18, and the cross slot connecting shaft (II) 34 is connected to the motor transmission shaft through the coupling 10. The nut (IV) 36 and the nut (III) 26 respectively play a limiting role on the elastic blade (II) 25 and the spring 35. Both the elastic blade (II) 25 and the spring 35 are fixedly connected to the sensor long sleeve 32. The spring 35 is used as an energy storage element here, which can better transmit torque. The improved torque actuator will not interfere with the object to which the torque is applied due to the contraction of the length.

[0055] Example 6

[0056] See Figures 21 to 23 The principle of the torque actuator in this embodiment is basically the same as that in Example 5. The main difference is that the elastic blade (II) 25 and the spring 35 are swapped in position. The spring 35 is embedded on the cross slot connecting shaft (III) 37, and two vertically crossed elastic blades (II) 25 are embedded on the cross slot connecting shaft (IV) 38. Similarly, both the elastic blade (II) 25 and the spring 35 are fixedly connected to the sensor long sleeve 32.

[0057] In summary, when the object whose torque needs to be adjusted is the secondary mirror of an astronomical optical telescope, the present invention can measure the torque value in real time and correct the mirror surface shape while applying torque to the secondary mirror; the torque actuator has a simple structure, clear principle, is easy to manufacture, and has good reliability and stability at the same time.

[0058] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A torque actuator, characterized in that, It includes an elastic rod, a torque sensor, and a motor. The torque sensor includes a torque receiving end, elastic vanes, and a torque output end. Torque sensitive elements are provided on the elastic vanes. A number of elastic vanes are arranged circumferentially, and the central axes of the number of elastic vanes are consistent with the extending direction of the elastic rod. The torque receiving end is connected to the motor through a coupling and transmits the torque output by the motor to the elastic vanes. The torque output end transmits the torque to the elastic rod by connecting with the elastic vanes. The elastic rod is connected to the object whose torque is to be adjusted.

2. The torque actuator according to claim 1, characterized in that, The torque receiving end includes a connecting shaft and a receiving end connecting plate. The torque output end includes an output end connecting plate. One end of the connecting shaft is key-connected to the coupling, and the other end is fixed to the receiving end connecting plate. One end of the elastic rod is connected to the object whose torque is to be adjusted, and the other end is fixed to the output end connecting plate. A number of elastic vanes are fixedly connected between the receiving end connecting plate and the output end connecting plate independently of each other.

3. A torque actuator according to claim 1, characterized in that, The torque receiving end includes a connecting shaft and a receiving end connecting plate. The torque output end includes an output end connecting plate. One end of the connecting shaft is key-connected to the coupling, and the other end is fixed to the receiving end connecting plate. One end of the elastic rod is connected to the object whose torque is to be adjusted, and the other end is fixed to the output end connecting plate. A squirrel-cage cylinder is fixedly installed between the receiving end connecting plate and the output end connecting plate. A number of through holes are provided on the side surface of the squirrel-cage cylinder circumferentially, and adjacent through holes are separated by the elastic vanes.

4. A torque actuator according to claim 1, characterized in that, The torque receiving end includes a connecting shaft. The torque output end includes a sensor sleeve and an output end connecting plate. One end of the connecting shaft is key-connected to the coupling, and the other end is a free end without connection relationship. The inner sides of a number of elastic vanes are fixedly installed on the main body of the connecting shaft. The outer sides of the elastic vanes are fixedly connected to the sensor sleeve. One end of the sensor sleeve is fixedly connected to the output end connecting plate, and the other end is a free end without connection relationship. One end of the elastic rod is connected to the object whose torque is to be adjusted, and the other end is fixed to the output end connecting plate.

5. A torque actuator according to claim 1, characterized in that, The torque receiving end includes a connecting shaft. The torque output end includes an elastic connecting piece and an output end connecting plate. One end of the connecting shaft is key-connected to the coupling, and the other end is a free end without connection relationship. The inner sides of a number of elastic vanes are fixedly installed on the main body of the connecting shaft. The outer sides of the elastic vanes are connected and fastened through an elastic vane connecting plate. The elastic vane connecting plate is connected to the output end connecting plate through the elastic connecting piece. One end of the elastic rod is connected to the object whose torque is to be adjusted, and the other end is fixed to the output end connecting plate.

6. A torque actuator according to claim 1, characterized in that, The torque receiving end includes a receiving end connecting shaft, a spiral spring, and a sensor sleeve. The torque output end includes an output end connecting shaft. One end of the receiving end connecting shaft is key-connected to the coupling, and the other end is a free end without connection relationship. The inner end of the spiral spring is connected to the receiving end connecting shaft, and the outer end of the spiral spring is connected to the sensor sleeve. The inner sides of a number of elastic vanes are fixedly installed on the main body of the output end connecting shaft. The outer sides of the elastic vanes are fixedly connected to the sensor sleeve. One end of the output end connecting shaft is fixedly connected to one end of the elastic rod, and the other end is a free end without connection relationship. The other end of the elastic rod is connected to the object whose torque is to be adjusted.

7. A torque actuator according to claim 1, characterized in that, The torque receiving end includes a receiving end connecting shaft, and the torque output end includes an output end connecting shaft, a sensor sleeve and a spring. One end of the receiving end connecting shaft is key-connected to the coupling, and the other end is a free end without a connection relationship. The inner sides of a plurality of elastic blades are fixedly installed on the main body of the receiving end connecting shaft, and the outer sides of the elastic blades are fixedly connected to the sensor sleeve. One end of the output end connecting shaft is fixedly connected to one end of the elastic rod, and the other end is a free end without a connection relationship. The other end of the elastic rod is connected to the object to be torque-adjusted. The inner end of the spring is connected to the output end connecting shaft, and the outer end of the spring is connected to the sensor sleeve.

8. A torque actuator according to claim 1, characterized in that, The elastic rod includes a connecting member, a universal joint and an elastic thin rod. The two ends of the elastic thin rod are respectively connected to the connecting member through the universal joint.

9. A torque actuator according to claim 1, characterized in that, The object to be torque-adjusted is the secondary mirror of an astronomical optical telescope, and the torque actuator is used to apply torque at the pivot of the secondary mirror floating support structure so as to adjust the surface shape of the secondary mirror of the astronomical optical telescope.

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