Stroke detection device of thread motor

Abstract

The invention belongs to the technical field of motion detection of piezoelectric driving elements, and particularly relates to a stroke detection device of a threaded motor, which comprises a rotary part, a shell assembly, a driving part, a driving part, a driving part, a driving part, a driving part and a driving part, and is characterized in that the rotary part is coaxially arranged with a screw rod and is in circumferential rotation and axial fixed connection with the shell assembly; the magnetic transmission mechanism is arranged between the rotating part and the screw rod, and the magnetic transmission mechanism is configured to enable the rotating part to synchronously rotate along with the screw rod under the condition that the rotating part is not in contact with the screw rod; the coding ring is coaxially and fixedly arranged relative to the rotating part; and the reading head is fixedly arranged on the shell assembly and is arranged opposite to the coding ring. According to the invention, the problems of complex structure, high installation precision requirement, friction loss and the like caused by axial movement of the traditional coding disc along with the screw rod are effectively solved; therefore, the mechanical structure is simplified, the manufacturing cost is reduced, energy loss caused by transmission friction is avoided, and the motion control precision and the overall working performance of the thread piezoelectric motor are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of motion detection of piezoelectric drive elements, and particularly relates to a stroke detection device for a threaded motor. Background Art

[0002] The threaded piezoelectric motor uses a piezoelectric material to drive an oscillator to vibrate, and then drives a screw to rotate through the vibration of the oscillator. The screw cooperates with a nut to achieve high-precision axial feeding of the screw. In order to further improve the motion control accuracy of the threaded piezoelectric motor, the stroke of the screw can be detected, and the detection signal is sent to a controller. The controller controls the working parameters of the piezoelectric material in real time according to the detection signal, thereby realizing closed-loop control of the threaded piezoelectric motor.

[0003] The existing stroke detection method generally directly sets an encoding disk on the screw, and then uses a reading head to detect the encoding disk. The defect of this method is that since the encoding disk follows the screw for axial feeding, and the effective detection range of the reading head is limited, the reading head must also follow the screw for axial feeding, and at the same time, displacement in other directions of the reading head needs to be avoided. This requires a complex mechanical following mechanism to be set between the screw and the reading head. This mechanical following mechanism not only has extremely high requirements for installation accuracy, resulting in an increase in manufacturing cost, but also causes unnecessary energy loss due to friction generated during the transmission process, reducing the working performance of the threaded piezoelectric motor. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a stroke detection device for a threaded motor that can reduce the assembly difficulty and energy loss.

[0005] To achieve the above object and other related objects, the present invention provides a stroke detection device for a threaded motor. The threaded motor includes a housing assembly, as well as a nut, a screw, and a piezoelectric drive device installed in the housing assembly. The nut is fixedly connected to the housing assembly, the screw is threadedly connected to the nut, and the piezoelectric drive device is configured to be able to drive the screw to rotate relative to the nut; The stroke detection device includes: A rotating part, coaxially arranged with the screw, and the rotating part is circumferentially rotatable and axially fixedly connected to the housing assembly; A magnetic drive mechanism, arranged between the rotating part and the screw, and the magnetic drive mechanism is configured to enable the rotating part to synchronously rotate with the screw without contacting the screw; An encoding ring, coaxially and fixedly arranged relative to the rotating part; A reading head, fixedly installed on the housing assembly and arranged opposite to the encoding ring.

[0006] In an alternative embodiment of the present invention, the magnetic drive mechanism includes a first permanent magnet and a second permanent magnet. The first permanent magnet is fixedly connected to the screw, and the second permanent magnet is fixedly connected to the rotating part. The first permanent magnet and the second permanent magnet are opposite to each other and arranged at intervals. The magnetic poles of the first permanent magnet and the first permanent magnet are arranged along the circumferential or tangential direction of the screw, and the magnetic pole arrangement directions of the first permanent magnet and the second permanent magnet are opposite.

[0007] In an alternative embodiment of the present invention, the length of the second permanent magnet in the axial direction of the screw is greater than the length of the first permanent magnet in the axial direction of the screw; and / or the length of the second permanent magnet in the length direction of the screw is greater than or equal to the preset stroke of the screw in the axial direction.

[0008] In an alternative embodiment of the present invention, the rotating part includes a cylindrical body made of a light non-metallic material. The cylindrical body is rotatably connected to the housing assembly through a bearing. The second permanent magnet is embedded in the inner ring surface of the cylindrical body. An electromagnetic shielding layer is provided on the outer ring surface of the cylindrical body, and the coding ring is arranged outside the electromagnetic shielding layer.

[0009] In an alternative embodiment of the present invention, the rotating part includes a cylindrical body. A clutch mechanism is provided between the inner ring surface of the cylindrical body and the screw. The clutch mechanism is configured to be able to switch between the following two states: Combined state: The clutch mechanism mechanically connects the screw and the cylindrical body, and forms a circumferential fixed and axial sliding fit between the two. Disengaged state: The clutch mechanism disconnects the mechanical connection between the screw and the cylindrical body.

[0010] In an alternative embodiment of the present invention, a nut is provided at one end of the screw located inside the cylindrical body. The clutch mechanism includes a first keyway provided on the outer ring surface of the nut, a second keyway provided on the inner ring surface of the cylindrical body, and a key bar movably arranged between the nut and the cylindrical body. The first keyway and the second keyway are arranged opposite to each other. The key bar is movably arranged along the radial direction of the cylindrical body, so that the key bar can switch between the following work positions: Work position one: In response to the disengaged state, the key bar retracts into the second keyway. Work position two: In response to the combined state, the key bar bridges between the first keyway and the second keyway.

[0011] In an alternative embodiment of the present invention, the rotary part further includes a knob fixedly connected to the cylindrical body. A switching mechanism is provided on the knob. The switching mechanism is connected to the key strip. The switching mechanism is assembled to be capable of driving the key strip to switch between the first working position and the second working position, and capable of holding the key strip at the first working position or the second working position.

[0012] In an alternative embodiment of the present invention, the switching mechanism includes a sliding part and a driving shaft. The sliding part is movably connected to the knob along the radial direction of the knob. The sliding part is fixedly connected to the key strip. The driving shaft is rotatably connected to the knob, and the axis of the driving shaft is perpendicular to the sliding direction of the sliding part. A flat surface is provided on the circumferential surface of the driving shaft. The distance from the flat surface to the center of the driving shaft is less than the radius of the driving shaft. An elastic element is provided between the sliding part and the knob. The elastic element is configured such that its elastic force can drive the sliding part to abut against the driving shaft. When the sliding part abuts against the flat surface, the key strip is at the second working position. When the sliding part abuts against the circumferential surface of the driving shaft other than the flat surface, the key strip is at the first working position.

[0013] In an alternative embodiment of the present invention, the sliding part is a plate-like structure, and the elastic element is a reed integrally formed with the sliding part.

[0014] In an alternative embodiment of the present invention, visual marks are respectively provided on the driving shaft and the knob. When the visual marks on the driving shaft and the knob are aligned with each other, the sliding part abuts against the flat surface.

[0015] The technical effect of the present invention is as follows: By providing a rotary part coaxial with the screw but axially fixed, and using a magnetic drive mechanism to achieve non-contact synchronous rotation of the rotary part and the screw, and at the same time fixing the coding ring to the rotary part and the reading head to the housing assembly, the present invention effectively solves the problems of complex structure, high installation precision requirements and frictional losses caused by the traditional coding disk following the axial movement of the screw. Specifically, due to the non-contact drive, the tolerance of the matching precision between the rotary part and the screw is relatively high, which greatly reduces the installation difficulty of the coding ring. At the same time, since the coding ring no longer follows the screw to move axially, the reading head can be directly fixed to the housing assembly, which not only reduces the assembly difficulty, but also fundamentally avoids the detection error caused by the movement of the reading head. This solution not only simplifies the mechanical structure, reduces the manufacturing cost, but also avoids the energy loss caused by transmission friction, significantly improves the motion control precision and overall working performance of the threaded piezoelectric motor, and realizes high-reliability and low-energy-consumption closed-loop control. Description of the Drawings

[0016] Figure 1It is a perspective view of the threaded motor provided by the embodiment of the present invention; Figure 2 It is a cross-sectional view of the threaded motor provided by the embodiment of the present invention; Figure 3 It is Figure 2 The partial enlarged view I of Figure 4 It is Figure 3 The A-A cross-sectional view of Figure 5 It is Figure 3 The B-B cross-sectional view of Figure 6 It is an exploded view of the threaded motor provided by the embodiment of the present invention; Figure 7 It is a perspective view of the driving part of the threaded motor provided by the embodiment of the present invention; Figure 8 It is a perspective view of the stroke detection part of the threaded motor provided by the embodiment of the present invention; Figure 9 It is an exploded view of the switching mechanism provided by the embodiment of the present invention; Explanation of reference numerals: 10, housing assembly; 11, upper housing; 12, middle housing; 13, lower housing; 20, nut; 30, screw; 31, first permanent magnet; 32, nut; 33, first keyway; 40, piezoelectric drive device; 50, rotating part; 51, cylindrical body; 511, second keyway; 52, second permanent magnet; 53, electromagnetic shielding layer; 54, coding ring; 55, bearing; 56, knob; 57, drive shaft; 571, flat surface; 572, visualization mark; 58, sliding part; 581, elastic element; 59, key bar; 60, reading head. Detailed implementation manners

[0017] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0018] It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0019] Please refer to Figures 1 to 9 As shown, an embodiment of the present invention provides a threaded motor, which mainly includes a piezoelectric drive part and a stroke detection part. The piezoelectric drive part includes a housing assembly 10, and a nut 20, a screw 30 and a piezoelectric drive device 40 mounted on the housing assembly 10. In a specific embodiment, for the convenience of assembly and processing, the housing assembly 10 can be set as multiple detachable parts. For example, the housing assembly 10 is divided into an upper housing 11, a middle housing 12 and a lower housing 13. The nut 20 is fixedly connected to the housing assembly 10, the screw 30 is threadedly connected to the nut 20, and the piezoelectric drive device 40 is configured to be able to drive the screw 30 to rotate relative to the nut 20. It should be noted that the present invention mainly makes improvements to the stroke detection part. Therefore, other specific details of the piezoelectric drive part will not be elaborated. The specific implementation manner of the above piezoelectric drive device 40 has no special limitation and can be selected from the prior art.

[0020] The following will detail the stroke detection device of the present invention in combination with specific embodiments: Please refer to Figures 2 to 4 、 Figures 6 to 8 As shown, the stroke detection device provided by the embodiment of the present invention includes a rotating part 50, a magnetic transmission mechanism, a coding ring 54 and a reading head 60. The rotating part 50 is coaxially arranged with the screw 30, and the rotating part 50 is circumferentially rotatable and axially fixedly connected to the housing assembly 10. The magnetic transmission mechanism is arranged between the rotating part 50 and the screw 30, and the magnetic transmission mechanism is configured to enable the rotating part 50 to synchronously rotate with the screw 30 without contacting the screw 30. The coding ring 54 is coaxially and fixedly arranged relative to the rotating part 50. The reading head 60 is fixedly installed on the housing assembly 10 and is arranged opposite to the coding ring 54. The present invention solves the problems of complex structure, high installation accuracy requirements and frictional loss caused by the traditional coding disk following the axial movement of the screw 30 by setting a rotating part 50 that is coaxially arranged with the screw 30 but axially fixed, and using a magnetic transmission mechanism to achieve non-contact synchronous rotation of the rotating part 50 and the screw 30. At the same time, the coding ring 54 is fixed to the rotating part 50 and the reading head 60 is fixed to the housing assembly 10. Specifically, due to the non-contact transmission, the tolerance of the matching accuracy between the rotating part 50 and the screw 30 is relatively high, which greatly reduces the installation difficulty of the coding ring 54. At the same time, since the coding ring 54 no longer follows the screw 30 to move axially, the reading head 60 can be directly fixed on the housing assembly 10, which not only reduces the assembly difficulty, but also fundamentally avoids the detection error caused by the movement of the reading head 60. This solution not only simplifies the mechanical structure, reduces the manufacturing cost, but also avoids the energy loss caused by transmission friction, significantly improves the motion control accuracy and overall working performance of the threaded piezoelectric motor, and realizes high-reliability and low-energy-consumption closed-loop control.

[0021] Please refer to Figure 3 and Figure 4 As shown, in an alternative embodiment of the present invention, the magnetic drive mechanism includes a first permanent magnet 31 and a second permanent magnet 52. The first permanent magnet 31 is fixedly connected to the screw 30, and the second permanent magnet 52 is fixedly connected to the rotating part 50. The first permanent magnet 31 and the second permanent magnet 52 are opposite and spaced apart; the magnetic poles of the first permanent magnet 31 and the first permanent magnet 31 are arranged along the circumferential or tangential direction of the screw 30, and the magnetic pole arrangement directions of the first permanent magnet 31 and the second permanent magnet 52 are opposite. In this embodiment, a pair of permanent magnets with circumferential or tangential magnetic pole arrangements is used as the magnetic drive mechanism. Through the non-contact magnetic coupling effect between the first permanent magnet 31 and the second permanent magnet 52, while ensuring the synchronous rotation of the screw 30 and the rotating part 50, the friction loss caused by mechanical contact is completely eliminated. The design of the reverse magnetic pole arrangement enhances the magnetic field coupling efficiency, makes the transmission more stable and reliable, further simplifies the structure and reduces the requirement for installation accuracy, and at the same time avoids the energy loss problem of traditional mechanical follower mechanisms, significantly improving the transmission efficiency and closed-loop control accuracy of the threaded piezoelectric motor.

[0022] Please refer to Figure 3 As shown, in an alternative embodiment of the present invention, the length of the second permanent magnet 52 in the axial direction of the screw 30 is greater than the length of the first permanent magnet 31 in the axial direction of the screw 30; and / or the length of the second permanent magnet 52 in the length direction of the screw 30 is greater than or equal to the preset stroke of the screw 30 in the axial direction. In this embodiment, by designing the axial length of the second permanent magnet 52 to be greater than that of the first permanent magnet 31 or covering the preset stroke of the screw 30, it is ensured that during the axial feeding process of the screw 30, the first permanent magnet 31 is always within the magnetic field action range of the second permanent magnet 52, so that stable magnetic coupling transmission can be maintained at any position. This design effectively avoids the problems of magnetic force interruption or fluctuation caused by the axial movement of the screw 30, ensures the full-range synchronous rotation of the rotating part 50 and the screw 30, further improves the continuity of stroke detection and the reliability of closed-loop control, and at the same time does not require additional adjustment mechanisms, maintaining the simplicity of the structure.

[0023] Please refer to Figure 3 and Figure 4 and Figure 8As shown, in an alternative embodiment of the present invention, the rotating part 50 includes a cylindrical body 51 made of a lightweight non-metallic material, such as plastic or ceramic. The cylindrical body 51 is rotatably connected to the housing assembly 10 through a bearing 55. The second permanent magnet 52 is embedded in the inner ring surface of the cylindrical body 51. An electromagnetic shielding layer 53 is provided on the outer ring surface of the cylindrical body 51. The coding ring 54 is arranged outside the electromagnetic shielding layer 53. In this embodiment, the use of the lightweight non-metallic cylindrical body 51 reduces the inertia of the rotating part 50 and the load on the screw 30. At the same time, the hierarchical design of the embedded permanent magnet and the external electromagnetic shielding layer 53 effectively isolates the magnetic field interference of the second permanent magnet 52 on the coding ring 54 and the circuit of the reading head 60. The bearing 55 support structure ensures smooth rotation of the rotating part 50, and the external layout of the coding ring 54 further enhances the stability of signal detection. Overall, the coordinated optimization of high-precision detection and low driving load is achieved, which not only ensures the magnetic transmission efficiency but also improves the anti-interference ability of the closed-loop control.

[0024] Please refer to Figures 4 to 9 As shown, in an alternative embodiment of the present invention, a clutch mechanism is provided between the inner ring surface of the cylindrical body 51 and the screw 30. The clutch mechanism is configured to be able to switch between the following two states: the engaged state, in which the clutch mechanism mechanically connects the screw 30 and the cylindrical body 51 and forms a circumferential fixed and axial sliding fit between them; and the disengaged state, in which the clutch mechanism disconnects the mechanical connection between the screw 30 and the cylindrical body 51. In this embodiment, the clutch mechanism realizes the flexible switching between two working modes: in the disengaged state, the mechanical connection between the screw 30 and the cylindrical body 51 is released. At this time, the magnetic drive mechanism works alone to ensure high-precision closed-loop control during normal operation; while in the engaged state, the screw 30 and the cylindrical body 51 are circumferentially fixed and axially slidably fitted through mechanical connection. At this time, the screw 30 can be directly manually driven by the rotating part 50 to move axially quickly, while avoiding the mechanical torque on the magnetic drive components. This design not only retains the precision control advantage of non-contact magnetic drive but also provides a convenient manual operation mode for system debugging and maintenance, significantly improving the practicability and reliability of the equipment.

[0025] Please refer to Figure 4 、 Figure 7 、 Figure 8As shown, in an alternative embodiment of the present invention, one end of the screw 30 located within the cylindrical body 51 is provided with a nut 32. The clutch mechanism includes a first keyway 33 provided on the outer circumferential surface of the nut 32, a second keyway 511 provided on the inner circumferential surface of the cylindrical body 51, and a key bar 59 movably disposed between the nut 32 and the cylindrical body 51. The first keyway 33 and the second keyway 511 are oppositely arranged, and the key bar 59 is movably disposed along the radial direction of the cylindrical body 51 so that the key bar 59 can be switched between the following working positions: Working position one, in response to the disengaged state, the key bar 59 retracts into the second keyway 511; and working position two, in response to the engaged state, the key bar 59 bridges between the first keyway 33 and the second keyway 511. This embodiment realizes a reliable switching of the clutch state through the design of the keyway and the radially movable key bar 59: in the disengaged state, the key bar 59 retracts into the second keyway 511 of the cylindrical body 51, enabling the magnetic drive mechanism to work independently and ensuring high-precision closed-loop control; in the engaged state, the key bar 59 radially extends and simultaneously engages into the first keyway 33 of the nut 32 and the second keyway 511 of the cylindrical body 51, forming a circumferential rigid connection. At this time, the screw 30 can be manually and quickly driven to axially move through the rotating part 50. This mechanical interlock structure not only has reliable switching action and high contact rigidity, but also completely avoids the problem of axial space occupation of traditional clutches. While ensuring the accuracy of magnetic drive, it greatly improves the convenience and reliability of manual operation of the equipment.

[0026] Please refer to Figure 3 、 Figure 5 、 Figure 6 As shown, in an alternative embodiment of the present invention, the rotating part 50 further includes a knob 56 fixedly connected to the cylindrical body 51. The knob 56 is provided with a switching mechanism, the switching mechanism is connected to the key bar 59, and the switching mechanism is assembled to be able to drive the key bar 59 to switch between the working position one and the working position two and be able to hold the key bar 59 in the working position one or the working position two. This embodiment realizes a one-key quick switching of the clutch state by integrating the switching mechanism on the knob 56 and controlling the movement of the key bar 59 in a linkage manner: the operator can accurately drive the key bar 59 to radially expand and contract through the switching mechanism, and stably lock it in the working position one or the working position two, which not only avoids the complex operation process of traditional clutch mechanisms, but also ensures the reliable maintenance of the working state through the mechanical self-locking characteristic, significantly improving the equipment debugging and maintenance efficiency.

[0027] Please refer to Figure 3 、 Figure 5 、 Figure 9As shown, in an alternative embodiment of the present invention, the switching mechanism includes a sliding portion 58 and a drive shaft 57. The sliding portion 58 is movably connected to the knob 56 along the radial direction of the knob 56. The sliding portion 58 is fixedly connected to the key strip 59. The drive shaft 57 is rotatably connected to the knob 56, and the axis of the drive shaft 57 is perpendicular to the sliding direction of the sliding portion 58. A flat surface 571 is provided on the circumferential surface of the drive shaft 57. The distance from the flat surface 571 to the center of the drive shaft 57 is less than the radius of the drive shaft 57. An elastic element 581 is provided between the sliding portion 58 and the knob 56. The elastic element 581 is configured such that its elastic force can drive the sliding portion 58 to abut against the drive shaft 57. When the sliding portion 58 abuts against the flat surface 571, the key strip 59 is located at the second station. When the sliding portion 58 abuts against the circumferential surface of the drive shaft 57 other than the flat surface 571, the key strip 59 is located at the first station. In this embodiment, through the cooperation structure of the drive shaft 57 and the sliding portion 58, combined with the self-resetting function of the elastic element 581, highly reliable switching and locking of the clutch state are achieved: when the drive shaft 57 is rotated so that the flat surface 571 faces the sliding portion 58, the elastic element 581 pushes the sliding portion 58 to move radially inward, driving the key strip 59 into the second station; when the drive shaft 57 rotates to the arc surface facing the sliding portion 58, the sliding portion 58 is pushed out, and the key strip 59 retracts to the first station. This cam-type switching mechanism uses geometric constraints to achieve two-way self-locking without the need for an additional locking device, which not only ensures the accuracy and holding force of the state switching, but also eliminates mechanical clearances through the elastic element 581. The overall structure is compact, the operating torque is small, and the stability and service life of the clutch control are significantly improved.

[0028] Please refer to Figure 9 As shown, in an alternative embodiment of the present invention, the sliding portion 58 is a plate-like structure, and the elastic element 581 is a reed integrally formed with the sliding portion 58. In this embodiment, by designing the sliding portion 58 as a plate-like structure and integrally forming it with the reed, the number of parts and the assembly process are greatly simplified, and the manufacturing cost is reduced; the integrated elastic structure eliminates the problems of eccentric loading or jamming that may occur in traditional independent springs, ensuring the smoothness and consistency of the movement of the sliding portion 58. At the same time, the compact layout of the reed optimizes the space utilization rate, enabling the entire switching mechanism to achieve higher reliability and durability in a limited space, and further improving the accuracy of the clutch state switching and the operating feel.

[0029] Please refer to Figure 9As shown, in an alternative embodiment of the present invention, a visualization mark 572 is provided on the drive shaft 57. When the visualization mark 572 on the drive shaft 57 aligns with a preset mark on the knob 56, the sliding portion 58 abuts against the flat surface 571. In this embodiment, by providing aligned visualization marks 572 on the drive shaft 57 and the knob 56, the operator can intuitively and quickly determine the real-time state of the clutch mechanism, significantly improving the convenience of operation. When the marks are aligned, the operator can clearly confirm that the key strip 59 has been accurately switched to station two, avoiding control errors caused by misjudgment. At the same time, it reduces the difficulty of equipment debugging and maintenance, effectively preventing mechanical interference or control failure problems caused by incomplete state switching, and further enhancing the operation safety and reliability of the system.

[0030] In summary, the present invention solves the problems of complex structure, high installation precision requirements, and frictional losses caused by the traditional code disk following the axial movement of the screw 30 by providing a rotating part 50 coaxial with the screw 30 but axially fixed and using a magnetic drive mechanism to achieve non-contact synchronous rotation of the rotating part 50 and the screw 30. Specifically, due to the non-contact drive, the tolerance for the matching precision between the rotating part 50 and the screw 30 is relatively high, which greatly reduces the installation difficulty of the code ring 54. At the same time, since the code ring 54 no longer moves axially with the screw 30, the reading head 60 can be directly fixed on the housing assembly 10, not only reducing the assembly difficulty but also fundamentally avoiding the detection error caused by the movement of the reading head 60. This solution not only simplifies the mechanical structure, reduces the manufacturing cost, but also avoids the energy loss caused by transmission friction, significantly improving the motion control precision and overall working performance of the threaded piezoelectric motor, and achieving high-reliability and low-energy-consumption closed-loop control. The present invention realizes flexible switching between two working modes through a clutch mechanism: in the disengaged state, the mechanical connection between the screw 30 and the cylindrical body 51 is released, and at this time, the magnetic drive mechanism works alone to ensure high-precision closed-loop control during normal operation; while in the engaged state, the screw 30 and the cylindrical body 51 are circumferentially fixed and axially slidably mated through a mechanical connection. At this time, the screw 30 can be directly manually driven to move axially quickly through the rotating part 50, while avoiding the magnetic drive components from bearing mechanical torque. This design not only retains the precise control advantage of non-contact magnetic drive but also provides a convenient manual operation mode for system debugging and maintenance, significantly improving the practicality and reliability of the equipment.

[0031] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those of ordinary skill in the art within the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

[0032] In the description herein, numerous specific details are provided, such as examples of components and / or methods, to provide a thorough understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of the specific details or with other devices, systems, components, methods, components, materials, parts, and the like. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

Claims

1. A stroke detection device for a threaded motor. The threaded motor includes a housing assembly (10), as well as a nut (20), a screw (30), and a piezoelectric drive device (40) mounted on the housing assembly (10). The nut (20) is fixedly connected to the housing assembly (10), the screw (30) is threadedly connected to the nut (20), and the piezoelectric drive device (40) is configured to be able to drive the screw (30) to rotate relative to the nut (20). It is characterized in that The stroke detection device includes: A rotating part (50) coaxially arranged with the screw (30), and the rotating part (50) is circumferentially rotatable and axially fixedly connected to the housing assembly (10); A magnetic drive mechanism arranged between the rotating part (50) and the screw (30), and the magnetic drive mechanism is configured to enable the rotating part (50) to rotate synchronously with the screw (30) without contacting the screw (30); An encoding ring (54) fixedly arranged coaxially with respect to the rotating part (50); A reading head (60) fixedly installed on the housing assembly (10) and arranged opposite to the encoding ring (54).

2. The stroke detection device of the threaded motor according to claim 1, characterized in that, The magnetic drive mechanism includes a first permanent magnet (31) and a second permanent magnet (52). The first permanent magnet (31) is fixedly connected to the screw (30), the second permanent magnet (52) is fixedly connected to the rotating part (50), and the first permanent magnet (31) and the second permanent magnet (52) are opposite and spaced apart; the magnetic poles of the first permanent magnet (31) and the first permanent magnet (31) are arranged along the circumference or tangential direction of the screw (30), and the magnetic pole arrangement directions of the first permanent magnet (31) and the second permanent magnet (52) are opposite.

3. The stroke detection device of the threaded motor according to claim 2, characterized in that, The length of the second permanent magnet (52) in the axial direction of the screw (30) is greater than the length of the first permanent magnet (31) in the axial direction of the screw (30); and / or the length of the second permanent magnet (52) in the length direction of the screw (30) is greater than or equal to the preset stroke of the screw (30) in the axial direction.

4. The stroke detection device of the threaded motor according to claim 3, characterized in that, The rotating part (50) includes a cylindrical body (51) made of a light non-metallic material. The cylindrical body (51) is rotatably connected to the housing assembly (10) through a bearing (55). The second permanent magnet (52) is embedded in the inner ring surface of the cylindrical body (51), and an electromagnetic shielding layer (53) is provided on the outer ring surface of the cylindrical body (51). The encoding ring (54) is arranged outside the electromagnetic shielding layer (53).

5. The stroke detection device of the threaded motor according to claim 1, characterized in that, The rotating part (50) includes a cylindrical body (51), and a clutch mechanism is provided between the inner ring surface of the cylindrical body (51) and the screw (30). The clutch mechanism is configured to be able to switch between the following two states; Combined state, the clutch mechanism mechanically connects the screw (30) and the cylindrical body (51), and forms a circumferentially fixed and axially sliding fit between them; Disengaged state, the clutch mechanism disconnects the mechanical connection between the screw (30) and the cylindrical body (51).

6. The stroke detection device of the threaded motor according to claim 5, characterized in that, One end of the screw rod (30) located inside the cylindrical body (51) is provided with a nut (32). The clutch mechanism includes a first keyway (33) provided on the outer circumferential surface of the nut (32), a second keyway (511) provided on the inner circumferential surface of the cylindrical body (51), and a key bar (59) movably arranged between the nut (32) and the cylindrical body (51); the first keyway (33) and the second keyway (511) are arranged opposite to each other, and the key bar (59) is movably arranged along the radial direction of the cylindrical body (51) so that the key bar (59) can be switched between the following working positions: Working position one, in response to the disengaged state, the key bar (59) contracts into the second keyway (511); Working position two, in response to the engaged state, the key bar (59) bridges between the first keyway (33) and the second keyway (511).

7. The stroke detection device of the threaded motor according to claim 6, characterized in that, The rotating part (50) further includes a knob (56) fixedly connected to the cylindrical body (51). A switching mechanism is provided on the knob (56). The switching mechanism is connected to the key bar (59) and is assembled to be able to drive the key bar (59) to switch between the working position one and the working position two and to be able to hold the key bar (59) in the working position one or the working position two.

8. The stroke detection device of the threaded motor according to claim 7, characterized in that, The switching mechanism includes a sliding part (58) and a driving shaft (57). The sliding part (58) is movably connected to the knob (56) along the radial direction of the knob (56). The sliding part (58) is fixedly connected to the key bar (59). The driving shaft (57) is rotatably connected to the knob (56), and the axis of the driving shaft (57) is perpendicular to the sliding direction of the sliding part (58). A flat surface (571) is provided on the circumferential surface of the driving shaft (57). The distance from the flat surface (571) to the center of the driving shaft (57) is less than the radius of the driving shaft (57). An elastic element (581) is provided between the sliding part (58) and the knob (56). The elastic element (581) is configured such that its elastic force can drive the sliding part (58) to abut against the driving shaft (57). When the sliding part (58) abuts against the flat surface (571), the key bar (59) is in the working position two. When the sliding part (58) abuts against the circumferential surface of the driving shaft (57) other than the flat surface (571), the key bar (59) is in the working position one.

9. The stroke detection device of the threaded motor according to claim 8, characterized in that, The sliding part (58) is of a plate-like structure, and the elastic element (581) is a reed integrally formed with the sliding part (58).

10. The stroke detection device of the threaded motor according to claim 9, characterized in that, Visualization marks (572) are respectively provided on the driving shaft (57) and the knob (56). When the visualization marks (572) on the driving shaft (57) and the knob (56) are aligned with each other, the sliding part (58) abuts against the flat surface (571).

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