A stroke detection device for a threaded motor

Abstract

The present invention belongs to the technical field of motion detection of piezoelectric drive elements, and specifically relates to a stroke detection device for a threaded motor, comprising: a rotating part, which is coaxially arranged with the screw, and the rotating part rotates circumferentially and is fixedly connected to the housing assembly in the axial direction; a magnetic transmission mechanism, which is arranged between the rotating part and the screw, and the magnetic transmission mechanism is configured to enable the rotating part to rotate synchronously with the screw without contacting the screw; an encoding ring, which is coaxially fixed relative to the rotating part; and a reading head, which is fixedly mounted on the housing assembly and arranged opposite to the encoding ring. The present invention effectively solves the problems of complex structure, high installation precision requirements, and friction loss caused by the axial movement of the traditional encoding disk following the screw; it not only simplifies the mechanical structure and reduces manufacturing costs, but also avoids energy loss caused by transmission friction, significantly improving the motion control precision and overall working performance of the threaded piezoelectric motor.

Description

Technical Field

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

[0002] Threaded piezoelectric motors utilize piezoelectric materials to drive the vibration of a vibrator, which in turn drives the screw. The screw and nut work together to achieve high-precision axial feed of the screw. To further improve the motion control accuracy of threaded piezoelectric motors, the screw's stroke can be detected. This detection signal is sent to a controller, which uses this detection signal to control the piezoelectric material's operating parameters in real time, thereby achieving closed-loop control of the threaded piezoelectric motor.

[0003] Existing stroke detection methods typically place an encoder disc directly on the screw and then use a readout head to detect the encoder disc. This method has the drawback that, because the encoder disc follows the screw's axial feed, the effective detection range of the readout head is limited. Therefore, the readout head must also follow the screw's axial feed, while also preventing the readout head from shifting in other directions. This requires a complex mechanical tracking mechanism between the screw and the readout head. This mechanical tracking mechanism not only requires extremely high installation precision, increasing manufacturing costs, but also results in unnecessary energy loss due to friction during transmission, reducing the performance of the threaded piezoelectric motor. Summary of the Invention

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

[0005] To achieve the above-mentioned and other related objectives, the present invention provides a stroke detection device for a threaded motor, the threaded motor comprising a housing assembly, and a nut, a screw, and a piezoelectric drive device mounted on the housing assembly, wherein the nut is fixedly connected to the housing assembly, the screw is threadably connected to the nut, and the piezoelectric drive device is configured to drive the screw to rotate relative to the nut;

[0006] The stroke detection device includes:

[0007] A rotary portion is coaxially arranged with the screw, and the rotary portion is circumferentially rotatable and axially fixedly connected to the housing assembly;

[0008] a magnetic transmission mechanism disposed between the rotating portion and the screw, the magnetic transmission mechanism being configured to enable the rotating portion to rotate synchronously with the screw without contacting the screw;

[0009] An encoding ring is coaxially fixed relative to the rotating portion;

[0010] The reading head is fixedly mounted on the housing assembly and is arranged opposite to the encoding ring.

[0011] In an optional embodiment of the present invention, the magnetic transmission mechanism includes a first permanent magnet and a second permanent magnet, the first permanent magnet is fixedly connected to the screw, 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 circumference or tangent direction of the screw, and the magnetic poles of the first permanent magnet and the second permanent magnet are arranged in opposite directions.

[0012] In an optional 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.

[0013] In an optional embodiment of the present invention, the rotating part includes a cylindrical body made of a lightweight non-metallic material, the cylindrical body is rotatably connected to the shell assembly through a bearing, the second permanent magnet is embedded in the inner annular surface of the cylindrical body, the outer annular surface of the cylindrical body is provided with an electromagnetic shielding layer, and the encoding ring is arranged on the outside of the electromagnetic shielding layer.

[0014] In an optional embodiment of the present invention, the rotary portion includes a cylindrical body, and a clutch mechanism is provided between the inner annular surface of the cylindrical body and the screw, and the clutch mechanism is configured to be able to switch between the following two states;

[0015] In the engaged state, the clutch mechanism mechanically connects the screw and the cylindrical body, and forms a circumferentially fixed and axially sliding fit between the two;

[0016] In the disengaged state, the clutch mechanism disconnects the mechanical connection between the screw and the cylindrical body.

[0017] In an optional embodiment of the present invention, a nut is provided at one end of the screw located within the cylindrical body, and the clutch mechanism includes a first keyway provided on the outer annular surface of the nut, a second keyway provided on the inner annular surface of the cylindrical body, and a key bar movably provided between the nut and the cylindrical body; the first keyway and the second keyway are provided opposite to each other, and the key bar is movably provided along the radial direction of the cylindrical body so that the key bar can switch between the following working positions:

[0018] Station 1, in response to the disengaged state, the key bar is retracted into the second key slot;

[0019] Station two, in response to the combined state, the key bar is bridged between the first key groove and the second key groove.

[0020] In an optional embodiment of the present invention, the rotating part also includes a knob fixed to the cylindrical body, and a switching mechanism is provided on the knob. The switching mechanism is connected to the key bar, and the switching mechanism is assembled to be able to drive the key bar to switch between the work station one and the work station two, and to be able to keep the key bar at the work station one or the work station two.

[0021] In an optional embodiment of the present invention, the switching mechanism includes a sliding portion and a driving shaft, the sliding portion is movably connected to the knob along the radial direction of the knob, the sliding portion is fixedly connected to the key bar, 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 portion, 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 portion and the knob, the elastic element is configured so that its elastic force can drive the sliding portion to abut against the driving shaft, when the sliding portion abuts against the flat surface, the key bar is located in the second station, and when the sliding portion abuts against the circumferential surface of the driving shaft except the flat surface, the key bar is located in the first station.

[0022] In an optional embodiment of the present invention, the sliding portion is a plate-shaped structure, and the elastic element is a spring formed integrally with the sliding portion.

[0023] In an optional embodiment of the present invention, visual marks are respectively provided on the driving shaft and the knob, and when the visual marks on the driving shaft and the knob are aligned with each other, the sliding portion abuts against the flat surface.

[0024] The technical effect of the present invention is that: by providing a rotating part that is coaxial with the screw but axially fixed, and utilizing a magnetic transmission mechanism to achieve non-contact synchronous rotation of the rotating part and the screw, the encoder ring is fixed to the rotating part and the reading head is fixed to the housing assembly, thereby effectively solving the problems of complex structure, high installation precision requirements, and friction loss caused by the traditional encoder disk following the axial movement of the screw; specifically, due to the use of non-contact transmission, the tolerance of the fitting precision between the rotating part and the screw is high, which greatly reduces the difficulty of installing the encoder ring. At the same time, since the encoder ring no longer follows the axial movement of the screw, the reading head can be directly fixed to the housing assembly, which not only reduces the difficulty of assembly, but also fundamentally avoids the detection error caused by the movement of the reading head. This solution not only simplifies the mechanical structure and reduces manufacturing costs, 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, low-energy closed-loop control. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a three-dimensional diagram of a threaded motor provided by an embodiment of the present invention;

[0026] Figure 2 is a cross-sectional view of a threaded motor provided by an embodiment of the present invention;

[0027] Figure 3 yes Figure 2 I local enlarged view;

[0028] Figure 4 yes Figure 3 AA section view;

[0029] Figure 5 yes Figure 3 BB cross-sectional view;

[0030] Figure 6 is an exploded view of a threaded motor provided by an embodiment of the present invention;

[0031] Figure 7 is a perspective view of a threaded motor driving portion provided by an embodiment of the present invention;

[0032] Figure 8 is a three-dimensional diagram of a stroke detection portion of a threaded motor provided by an embodiment of the present invention;

[0033] Figure 9 is an exploded view of a switching mechanism provided by an embodiment of the present invention;

[0034] Explanation of the reference numerals in the accompanying drawings: 10. Shell assembly; 11. Upper shell; 12. Middle shell; 13. Lower shell; 20. Nut; 30. Screw; 31. First permanent magnet; 32. Nut; 33. First keyway; 40. Piezoelectric drive device; 50. Rotating portion; 51. Cylindrical body; 511. Second keyway; 52. Second permanent magnet; 53. Electromagnetic shielding layer; 54. Encoding ring; 55. Bearing; 56. Knob; 57. Drive shaft; 571. Flat surface; 572. Visual mark; 58. Sliding portion; 581. Elastic element; 59. Key bar; 60. Reading head. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention through specific examples. 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 embodiments. The 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 the following embodiments and features in the embodiments can be combined with each other unless they conflict.

[0036] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not 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 complex.

[0037] See also 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, wherein the piezoelectric drive part includes a shell assembly 10, and a nut 20, a screw 30 and a piezoelectric drive device 40 installed on the shell assembly 10; in a specific embodiment, in order to facilitate assembly and processing, the shell assembly 10 can be arranged into multiple detachable parts, for example, the shell assembly 10 is divided into an upper shell 11, a middle shell 12 and a lower shell 13; the nut 20 is fixed to the shell 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 is mainly an improvement made to the stroke detection part, so other specific details of the piezoelectric drive part are not repeated, and the specific implementation method of the above-mentioned piezoelectric drive device 40 is not particularly limited and can be selected from the existing technology.

[0038] The stroke detection device of the present invention is described in detail below with reference to specific embodiments:

[0039] See also Figures 2 to 4 、 Figures 6 to 8As shown, the stroke detection device provided by an embodiment of the present invention includes a rotating part 50, a magnetic transmission mechanism, an encoding 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 rotated and axially fixedly connected with 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 rotate synchronously with the screw 30 without contacting the screw 30; the encoding ring 54 is coaxially fixed relative to the rotating part 50; the reading head 60 is fixedly installed on the housing assembly 10 and is arranged opposite to the encoding ring 54. The present invention provides a rotating portion 50 that is coaxial with the screw 30 but axially fixed, and utilizes a magnetic transmission mechanism to achieve non-contact synchronous rotation of the rotating portion 50 and the screw 30. Furthermore, the encoder ring 54 is fixed to the rotating portion 50, and the read head 60 is fixed to the housing assembly 10. This effectively solves the problems of a traditional encoder disk that follows the axial movement of the screw 30, such as complex structure, high installation precision requirements, and friction loss. Specifically, due to the use of non-contact transmission, the tolerance for fit precision between the rotating portion 50 and the screw 30 is high, which greatly reduces the difficulty of installing the encoder ring 54. At the same time, since the encoder ring 54 no longer follows the axial movement of the screw 30, the read head 60 can be directly fixed to the housing assembly 10, which not only reduces the assembly difficulty but also fundamentally avoids detection errors caused by the movement of the read head 60. This solution not only simplifies the mechanical structure and reduces manufacturing costs, but also avoids 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, low-energy closed-loop control.

[0040] See also Figure 3 、 Figure 4 As shown, in an optional embodiment of the present invention, the magnetic transmission 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 portion 50. The first permanent magnet 31 and the second permanent magnet 52 are oppositely spaced and arranged. The magnetic poles of the first permanent magnet 31 and the second permanent magnet 31 are arranged along the circumference or tangent direction of the screw 30, and the magnetic poles of the first permanent magnet 31 and the second permanent magnet 52 are arranged in opposite directions. This embodiment uses a permanent magnet pair with circumferential or tangential magnetic poles as the magnetic transmission mechanism. Through the non-contact magnetic coupling between the first permanent magnet 31 and the second permanent magnet 52, the screw 30 and the rotating portion 50 are ensured to rotate synchronously while completely eliminating the friction loss caused by mechanical contact. The design of reverse pole arrangement enhances the magnetic field coupling efficiency, makes the transmission more stable and reliable, further simplifies the structure and reduces the requirements for installation accuracy, while avoiding the energy loss problem of traditional mechanical following mechanism, and significantly improves the transmission efficiency and closed-loop control accuracy of the threaded piezoelectric motor.

[0041] See also Figure 3 As shown, in an optional 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 axial stroke of the screw 30. 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 to cover the preset stroke of the screw 30, it is ensured that the first permanent magnet 31 is always within the magnetic field of the second permanent magnet 52 during the axial feed of the screw 30, thereby maintaining stable magnetic coupling transmission at any position. This design effectively avoids magnetic force interruption or fluctuation caused by axial movement of the screw 30, ensures full synchronous rotation of the rotating portion 50 and the screw 30, further improves the continuity of stroke detection and the reliability of closed-loop control, and eliminates the need for additional adjustment mechanisms, maintaining a simple structure.

[0042] See also Figure 3 、 Figure 4 、 Figure 8 As shown, in an optional embodiment of the present invention, the rotating portion 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 via a bearing 55. The second permanent magnet 52 is embedded in the inner annular surface of the cylindrical body 51, and an electromagnetic shielding layer 53 is provided on the outer annular surface of the cylindrical body 51. The encoder ring 54 is disposed outside the electromagnetic shielding layer 53. This embodiment utilizes a lightweight non-metallic cylindrical body 51 to reduce the inertia of the rotating portion 50 and the load on the screw 30. The layered 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 encoder ring 54 and the circuitry of the readhead 60. The bearing 55 support structure ensures smooth rotation of the rotating portion 50, while the external layout of the encoder ring 54 further enhances signal detection stability. Overall, this achieves the coordinated optimization of high-precision detection and low drive load, ensuring both magnetic transmission efficiency and improving the anti-interference performance of closed-loop control.

[0043] See also Figures 4 to 9As shown, in an optional embodiment of the present invention, a clutch mechanism is provided between the inner annular surface of the cylindrical body 51 and the screw 30. The clutch mechanism is configured to switch between two states: an engaged state, in which the clutch mechanism mechanically connects the screw 30 to the cylindrical body 51, forming a circumferentially fixed, axially sliding fit between the two; and a disengaged state, in which the clutch mechanism disconnects the mechanical connection between the screw 30 and the cylindrical body 51. This embodiment achieves flexible switching between two operating modes through the clutch mechanism: in the disengaged state, the screw 30 and the cylindrical body 51 are mechanically disconnected, and the magnetic transmission mechanism operates independently, ensuring high-precision closed-loop control during normal operation; in the engaged state, the screw 30 and the cylindrical body 51 are mechanically connected, forming a circumferentially fixed, axially sliding fit. In this state, the screw 30 can be manually driven directly through the rotating portion 50 for rapid axial movement, while preventing the magnetic transmission components from being subjected to mechanical torque. This design retains the precise control advantages of non-contact magnetic transmission while providing a convenient manual operation mode for system commissioning and maintenance, significantly improving the practicality and reliability of the device.

[0044] See also Figure 4 、 Figure 7 、 Figure 8 As shown, in an optional embodiment of the present invention, a nut 32 is provided at one end of the screw rod 30 located in the cylindrical body 51, and the clutch mechanism includes a first keyway 33 provided on the outer annular surface of the nut 32, a second keyway 511 provided on the inner annular surface of the cylindrical body 51, and a key bar 59 movably provided 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 provided along the radial direction of the cylindrical body 51 so that the key bar 59 can switch between the following stations: station one, in response to the disengaged state, the key bar 59 is contracted in the second keyway 511; and station two, in response to the engaged state, the key bar 59 is bridged between the first keyway 33 and the second keyway 511. This embodiment achieves reliable switching between clutch states through the design of a keyway and a radially movable key bar 59: in the disengaged state, the key bar 59 retracts into the second keyway 511 of the cylindrical body 51, allowing the magnetic transmission mechanism to operate independently and ensuring high-precision closed-loop control; in the engaged state, the key bar 59 extends radially and simultaneously engages the first keyway 33 of the nut 32 and the second keyway 511 of the cylindrical body 51, forming a circumferentially rigid connection. At this time, the screw rod 30 can be manually and quickly driven axially through the rotating portion 50. This mechanical interlocking structure not only provides reliable switching and high contact rigidity, but also completely avoids the axial space occupation problem of traditional clutches. While ensuring the accuracy of magnetic transmission, it significantly improves the convenience and reliability of manual operation of the equipment.

[0045] See also Figure 3 、 Figure 5 、 Figure 6 As shown, in an optional embodiment of the present invention, the rotating portion 50 further includes a knob 56 fixedly connected to the cylindrical body 51, and a switching mechanism is provided on the knob 56, and the switching mechanism is connected to the key bar 59, and the switching mechanism is configured to be able to drive the key bar 59 to switch between the workstation one and the workstation two, and to be able to maintain the key bar 59 at the workstation one or the workstation two. This embodiment realizes a one-touch 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 extend and retract through the switching mechanism, so that it is stably locked at the workstation one or the workstation two, which not only avoids the complicated operation process of the traditional clutch mechanism, but also ensures the reliable maintenance of the working state through the mechanical self-locking characteristics, significantly improving the efficiency of equipment commissioning and maintenance.

[0046] See also Figure 3 、 Figure 5 、 Figure 9 As shown, in an optional 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 bar 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 so 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 bar 59 is located in the second station, and when the sliding portion 58 abuts against the circumferential surface of the drive shaft 57 other than the flat surface 571, the key bar 59 is located in the first station. This embodiment achieves highly reliable switching and locking of the clutch state through the coordinated structure of the drive shaft 57 and the sliding portion 58, combined with the self-resetting function of the elastic element 581: 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 radially inward, driving the key bar 59 into station 2; when the drive shaft 57 rotates until the arc surface faces the sliding portion 58, the sliding portion 58 is ejected, and the key bar 59 returns to station 1. This cam-type switching mechanism uses geometric constraints to achieve bidirectional self-locking, eliminating the need for additional locking devices. This ensures both the accuracy and retention of state switching, while eliminating mechanical backlash 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.

[0047] See also Figure 9 As shown, in an optional embodiment of the present invention, the sliding portion 58 is a plate-like structure, and the elastic element 581 is a spring formed integrally with the sliding portion 58. By designing the sliding portion 58 as a plate-like structure and integrally forming it with the spring, this embodiment significantly simplifies the number of parts and assembly process, reducing manufacturing costs. The integrated elastic structure eliminates the potential for overloading or jamming associated with traditional independent springs, ensuring smooth and consistent movement of the sliding portion 58. The compact layout of the spring optimizes space utilization, enabling the entire switching mechanism to achieve higher reliability and durability within a limited space, further enhancing the precision and operational feel of clutch switching.

[0048] See also Figure 9 As shown, in an optional embodiment of the present invention, a visual mark 572 is provided on the drive shaft 57. When the visual mark 572 on the drive shaft 57 is aligned with the preset mark on the knob 56, the sliding portion 58 abuts against the flat surface 571. This embodiment enables the operator to intuitively and quickly judge the real-time status of the clutch mechanism by providing mutually aligned visual marks 572 on the drive shaft 57 and the knob 56, significantly improving the convenience of operation. When the marks are aligned, the operator can clearly confirm that the key bar 59 has been accurately switched to workstation two, avoiding control errors caused by misjudgment, while reducing the difficulty of equipment debugging and maintenance, effectively preventing mechanical interference or control failure caused by inadequate state switching, and further enhancing the operational safety and reliability of the system.

[0049] In summary, the present invention provides a rotating portion 50 that is coaxial with the screw 30 but axially fixed, and utilizes a magnetic transmission mechanism to achieve non-contact synchronous rotation of the rotating portion 50 and the screw 30. At the same time, the encoder ring 54 is fixed to the rotating portion 50 and the reading head 60 is fixed to the housing assembly 10. This effectively solves the problems of complex structure, high installation precision requirements, and friction loss caused by the traditional encoder disk following the axial movement of the screw 30. Specifically, due to the use of non-contact transmission, the tolerance of the fitting precision between the rotating portion 50 and the screw 30 is relatively high, which greatly reduces the difficulty of installing the encoder ring 54. At the same time, since the encoder ring 54 no longer follows the axial movement of the screw 30, the reading head 60 can be directly fixed to the housing assembly 10, which not only reduces the assembly difficulty but also fundamentally avoids detection errors caused by the movement of the reading head 60. This solution not only simplifies the mechanical structure and reduces manufacturing costs, but also avoids 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, low-energy closed-loop control. The present invention realizes flexible switching between two working modes through the clutch mechanism: in the disengaged state, the screw 30 and the cylindrical body 51 are mechanically released, and the magnetic transmission mechanism works alone to ensure high-precision closed-loop control during normal operation; in the engaged state, the screw 30 and the cylindrical body 51 are mechanically connected to form a circumferentially fixed and axially sliding fit. At this time, the screw 30 can be directly manually driven by the rotating part 50 to move axially quickly, while avoiding the magnetic transmission components from being subjected to mechanical torque; this design not only retains the precise control advantage of non-contact magnetic transmission, but also provides a convenient manual operation mode for system debugging and maintenance, significantly improving the practicality and reliability of the equipment.

[0050] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

[0051] In the description herein, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of the 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, assemblies, methods, components, materials, parts, etc. In other cases, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of the embodiments of the present invention.

Claims

1. A stroke detection device for a threaded motor, the threaded motor comprising a housing assembly (10), and a nut (20), a screw (30), and a piezoelectric drive device (40) mounted on the housing assembly (10), wherein 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 drive the screw (30) to rotate relative to the nut (20); It is characterized by: The stroke detection device includes: A rotating portion (50) is coaxially arranged with the screw (30), and the rotating portion (50) is circumferentially rotatable and axially fixedly connected to the housing assembly (10); a magnetic transmission mechanism disposed between the rotating portion (50) and the screw (30), the magnetic transmission mechanism being configured to enable the rotating portion (50) to rotate synchronously with the screw (30) without contacting the screw (30); An encoding ring (54) is coaxially fixedly arranged relative to the rotating portion (50); A reading head (60) is fixedly mounted on the housing assembly (10) and is 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 transmission mechanism includes a first permanent magnet (31) and a second permanent magnet (52), wherein the first permanent magnet (31) is fixedly connected to the screw (30), and the second permanent magnet (52) is fixedly connected to the rotating portion (50), and the first permanent magnet (31) and the second permanent magnet (52) are opposite to each other and spaced apart; the magnetic poles of the first permanent magnet (31) and the first permanent magnet (31) are arranged along the circumference or tangent direction of the screw (30), and the magnetic poles of the first permanent magnet (31) and the second permanent magnet (52) are arranged in opposite directions.

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 a 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 portion (50) includes a cylindrical body (51) made of a lightweight non-metallic material, the cylindrical body (51) is rotatably connected to the housing assembly (10) via a bearing (55), the second permanent magnet (52) is embedded in the inner annular surface of the cylindrical body (51), the outer annular surface of the cylindrical body (51) is provided with an electromagnetic shielding layer (53), and the encoding ring (54) is arranged on the outside of the electromagnetic shielding layer (53).

5. The stroke detection device of the threaded motor according to claim 1, characterized in that: The rotary portion (50) includes a cylindrical body (51), and a clutch mechanism is provided between the inner annular surface of the cylindrical body (51) and the screw (30), wherein the clutch mechanism is configured to be switchable between the following two states; In the coupled state, the clutch mechanism mechanically connects the screw (30) and the cylindrical body (51), and forms a circumferentially fixed and axially sliding fit between the two; In the 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: A nut (32) is provided at one end of the screw rod (30) located in the cylindrical body (51), and the clutch mechanism comprises a first keyway (33) provided on the outer annular surface of the nut (32), a second keyway (511) provided on the inner annular surface of the cylindrical body (51), and a key bar (59) movably provided 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 provided along the radial direction of the cylindrical body (51) so that the key bar (59) can be switched between the following positions: Station 1, in response to the disengaged state, the key bar (59) contracts into the second key slot (511); Station two, in response to the combined state, the key bar (59) is bridged between the first key groove (33) and the second key groove (511).

7. The stroke detection device of the threaded motor according to claim 6, characterized in that: The rotating portion (50) further includes a knob (56) fixedly connected to the cylindrical body (51), and a switching mechanism is provided on the knob (56). The switching mechanism is connected to the key bar (59), and the switching mechanism is configured to be able to drive the key bar (59) to switch between the work station one and the work station two, and to be able to keep the key bar (59) at the work station one or the work station two.

8. The stroke detection device for a threaded motor according to claim 7, characterized in that: The switching mechanism includes a sliding portion (58) and a drive shaft (57), wherein 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 bar (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), and a flat surface (571) is provided on the circumference of the drive shaft (57), and the distance from the flat surface (571) to the center of the drive shaft (57) is less than At the radius of the drive shaft (57), an elastic element (581) is provided between the sliding portion (58) and the knob (56), and the elastic element (581) is configured so 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 bar (59) is located at the second station. When the sliding portion (58) abuts against the peripheral surface of the drive shaft (57) other than the flat surface (571), the key bar (59) is located at the first station.

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

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

Images