A nuclear magnetic compatible linear pneumatic motor

Abstract

The application discloses a nuclear magnetic compatible linear pneumatic motor, which comprises an output shaft, a harmonic reducer, a turbine and a photoelectric encoder, wherein the output shaft is located in the center of the linear pneumatic motor and is provided with an external thread; the harmonic reducer comprises a rigid wheel which is sleeved on the output shaft and is threadedly connected with the output shaft; the turbine is sleeved on the output shaft and is located on one side of the harmonic reducer; the turbine is in transmission connection with the rigid wheel and is used for driving the rigid wheel to rotate so as to drive the output shaft to move linearly along the axial direction; the photoelectric encoder is sleeved on the output shaft and is located on the side of the turbine which is away from the harmonic reducer; and the photoelectric encoder is in transmission connection with the turbine. The overall volume and length of the harmonic reducer, the turbine and the photoelectric encoder can be utilized to assemble an output shaft with a larger length inside, and a larger output stroke can be realized by replacing the length of the output shaft; meanwhile, the output shaft is located in the center of the linear pneumatic motor, so that the stress load is more uniform.

Description

Technical Field

[0001] This application relates to the field of pneumatic motor technology, and more particularly to a nuclear magnetic compatibility linear pneumatic motor. Background Technology

[0002] Magnetic resonance imaging (MRI) is a radiation-free medical imaging technique used to capture 3D images of the human body, providing excellent resolution for accurate detection of anatomical features. MRI operates in a strong magnetic field environment, which precludes the use of conventional actuators (such as motors) and robots. Only actuators and robots made of MRI-compatible materials can be used; non-MRI-compatible materials must be placed away from the MRI scanner. The fundamental and key component of MRI-guided surgical robots is the MRI-compatible actuator.

[0003] Currently, the mainstream drive scheme for NMR-compatible linear actuators is achieved using NMR-compatible cylinders. However, the output stroke of NMR-compatible cylinders depends on the length of the cylinder's output shaft, resulting in a limited linear motion stroke. Furthermore, using existing NMR-compatible rotary actuators with gear mechanisms (gear and rack, worm gear) to output linear motion leads to the force load on the rotary actuator's output shaft being concentrated on one side of the shaft.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide a nuclear magnetic compatibility linear pneumatic motor that addresses the above-mentioned deficiencies of the prior art, thereby solving the problems of limited linear motion stroke and uneven force distribution in the prior art of nuclear magnetic compatibility driven motors.

[0006] The technical solution adopted in this application to solve the technical problem is as follows:

[0007] A nuclear magnetic resonance compatible linear pneumatic motor, comprising:

[0008] The output shaft has an external thread and is located at the center of the linear pneumatic motor;

[0009] Harmonic reducer; the harmonic reducer includes a rigid wheel, which is sleeved on the output shaft and threadedly connected to the output shaft;

[0010] A turbine is mounted on the output shaft and located on one side of the harmonic reducer; the turbine is connected to the rigid wheel drive and is used to drive the rigid wheel to rotate, so as to drive the output shaft to move linearly along the axial direction;

[0011] An optical encoder is mounted on the output shaft and located on the side of the turbine away from the harmonic reducer; the optical encoder is connected to the turbine in a drive connection.

[0012] The nuclear magnetic resonance compatible linear pneumatic motor is provided with at least one groove on the outer circumferential surface of the output shaft, the groove extending along the axial direction of the output shaft; the inner surface of the harmonic reducer and / or the photoelectric encoder is provided with a protrusion, the protrusion being slidably arranged in the groove.

[0013] The nuclear magnetic resonance compatible linear pneumatic motor, wherein there are two slides, which are symmetrically distributed radially along the output shaft.

[0014] The nuclear magnetic resonance compatible linear pneumatic motor, wherein the photoelectric encoder comprises:

[0015] An encoder bracket is fitted onto the output shaft; the output shaft is slidable relative to the encoder bracket.

[0016] A fiber optic plug aligner is mounted on the encoder bracket; the fiber optic plug aligner is provided with a light path and a receiving slot; the light path is connected to the receiving slot.

[0017] The encoding disk unit is rotatably disposed within the receiving slot; the encoding disk unit is used to block light so that the light path is in a disconnected state; the encoding disk unit is also used to avoid light so that the light path is in a conductive state;

[0018] A gear transmission assembly is located inside the encoder bracket and is connected to the turbine and the encoder disk respectively, so as to drive the encoder disk to rotate under the drive of the turbine.

[0019] The nuclear magnetic resonance compatible linear pneumatic motor, wherein the photoelectric encoder further includes:

[0020] Two mounting hole units; each mounting hole unit includes two mounting holes, which are symmetrically distributed along a straight line on both sides of the receiving groove and extend into the receiving groove to form a light path;

[0021] A ceramic core is located within the mounting hole and is used to fix the optical fiber;

[0022] The two light paths are not arranged in the same plane, and the rotation center of the encoder disk unit is located between the two light paths.

[0023] The nuclear magnetic resonance compatible linear pneumatic motor, wherein the encoder unit includes:

[0024] The first encoding disk is in the shape of a pentagonal prism; in the two light paths, one light path corresponds to the first encoding disk and is located on the rotation path of the corner of the first encoding disk;

[0025] The second encoding disk is in the shape of a pentagonal prism; in the two light paths, the other light path corresponds to the second encoding disk and is located on the rotation path of the corner of the second encoding disk;

[0026] The first and second encoding disks are coaxial and arranged vertically; the second encoding disk is rotated 162° relative to the center of the first encoding disk.

[0027] The nuclear magnetic resonance compatible linear pneumatic motor wherein the on and off states of the two optical paths can be the same or different to determine the rotation direction of the encoder disk unit.

[0028] The nuclear magnetic resonance compatible linear pneumatic motor, wherein the gear transmission assembly includes:

[0029] The first gear is coaxially arranged on the output shaft and is connected to the turbine for transmission, so as to rotate relative to the output shaft under the drive of the turbine;

[0030] The second gear meshes with the first gear and is connected to the encoder disk unit; the axial direction of the second gear is perpendicular to the axial direction of the first gear.

[0031] The nuclear magnetic resonance compatible linear pneumatic motor, wherein the harmonic reducer comprises:

[0032] A reducer fixing component is sleeved on the output shaft; the rigid wheel is rotatably connected to the reducer fixing component;

[0033] A flexible wheel is rotatably mounted on the output shaft and is connected to the turbine for transmission; the flexible wheel is located inside the rigid wheel and meshes with the rigid wheel;

[0034] A wave generator is rotatably mounted on the output shaft; the wave generator is connected to the turbine and engages with the inner circumferential surface of the flexure to drive the flexure to rotate.

[0035] The nuclear magnetic resonance compatible linear pneumatic motor, wherein the turbine comprises:

[0036] The stator is fitted onto the output shaft;

[0037] The rotor is sleeved on the output shaft and assembled inside the stator; both ends of the rotor extend outside the stator and are respectively connected to the harmonic reducer and the photoelectric encoder.

[0038] Beneficial effects: The output shaft described in this application is located at the center of the linear pneumatic motor, making the force load more uniform; at the same time, compared with the existing NMR-compatible cylinder, this application can utilize the overall volume and length of the harmonic reducer, the turbine and the photoelectric encoder to assemble a larger length output shaft inside; and a larger output stroke can be achieved by changing the length of the output shaft, and the torque, speed and position of the motor can be controlled by controlling the magnitude of the input airflow, which is conducive to a deeper level of dynamic model analysis. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the overall assembly structure of the nuclear magnetic compatibility linear pneumatic motor described in this application;

[0040] Figure 2 This is an exploded structural diagram of the nuclear magnetic resonance compatible linear pneumatic motor described in this application;

[0041] Figure 3 This is an exploded structural diagram of the photoelectric encoder described in this application;

[0042] Figure 4 This is a side view of the fiber optic plug aligner described in this application;

[0043] Figure 5 The image shown in the middle is a schematic diagram of the bottom structure of the fiber optic plug aligner described in this application;

[0044] Figure 6 This is a side view of the encoding disk unit described in this application;

[0045] Figure 7 This is a top view of the encoding disk unit described in this application;

[0046] Figure 8 This is a reference diagram showing the usage state of the encoding disk unit described in this application in its initial state;

[0047] Figure 9 This is a reference diagram showing the usage state of the encoding disk unit described in this application when it rotates counterclockwise from its initial state to the point where the first light path is in the conducting state and the second light path is in the blocking state;

[0048] Figure 10 This is a reference diagram showing the usage state of the encoding disk unit described in this application when it rotates counterclockwise from its initial state to the point where the first optical path is in the conducting state and the second optical path is in the conducting state;

[0049] Figure 11This is a reference diagram showing the usage state of the encoding disk unit described in this application when it rotates counterclockwise from its initial state to a state where the first light path is blocked and the second light path is open.

[0050] Figure 12 This is a reference diagram showing the usage state of the encoding disk unit described in this application when it rotates clockwise from its initial state to a state where the first light path is blocked and the second light path is open.

[0051] Figure 13 This is a reference diagram showing the usage state of the encoding disk unit described in this application when it rotates clockwise from its initial state to the point where the first optical path is in the conducting state and the second optical path is in the conducting state;

[0052] Figure 14 This is a reference diagram showing the usage state of the encoding disk unit described in this application when it rotates clockwise from its initial state to a state where the first light path is in the conducting state and the second light path is in the blocking state;

[0053] Figure 15 This is an exploded structural diagram of the harmonic reducer described in this application;

[0054] Figure 16 This is a schematic diagram of the assembly structure of the harmonic reducer and the output shaft described in this application;

[0055] Figure 17 This is a structural schematic diagram of the reducer fixing component described in this application;

[0056] Figure 18 This is a schematic diagram of the turbine described in this application;

[0057] Figure 19 This is a schematic diagram comparing the output signals of the first light path and the second light path when the encoding disk unit described in this application is rotated 72° counterclockwise from its initial state.

[0058] Figure 20 This is a schematic diagram comparing the output signals of the first light path and the second light path when the encoding disk unit described in this application is rotated 72° clockwise from its initial state.

[0059] Explanation of reference numerals in the attached figures:

[0060] 1-Output shaft; 10-Slide groove; 2-Harmonic reducer; 21-Rigid wheel; 22-Reducer fixing component; 23-Flexible wheel; 231-Spherical ball; 24-Wave generator; 25-Third bearing; 26-Fourth bearing; 3-Turbine; 31-Stator; 32-Rotor; 321-Slot; 33-Fifth bearing; 4-Photoelectric encoder; 401-Light path; 402-Light path; 41-Encoder bracket; 42-Fiber optic plug aligner; 421-Receiving slot; 43-Encoding disk unit; 431-First encoding disk; 432-Second encoding disk; 44-Gear transmission assembly; 441-First gear; 442-Second gear; 45-Mounting hole unit; 450-Mounting hole; 46-Ceramic core; 47-First bearing; 48-Second bearing; 5-Protrusion; 6-Insertion rib. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of this application clearer and more explicit, the following detailed description of this application is provided with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0062] This application provides a nuclear magnetic resonance compatible linear pneumatic motor, such as... Figure 1 As shown, the nuclear magnetic resonance compatible linear pneumatic motor includes: an output shaft 1, a harmonic reducer 2, a turbine 3, and a photoelectric encoder 4; the output shaft 1 passes sequentially through the harmonic reducer 2, the turbine 3, and the photoelectric encoder 4, and is located at the center of the linear pneumatic motor to ensure uniform force load. The output shaft 1 is movable relative to the harmonic reducer 2, the turbine 3, and the photoelectric encoder 4. The harmonic reducer 2 includes a rigid wheel 21, which is sleeved on the output shaft 1; the output shaft 1 has an external thread, and the rigid wheel 21 is threadedly connected to the output shaft 1.

[0063] The turbine 3 is mounted on the output shaft 1 and located on one side of the harmonic reducer 2; the turbine 3 is driven by the rigid wheel 21 and is used to drive the rigid wheel 21 to rotate. The photoelectric encoder 4 is mounted on the output shaft 1 and located on the side of the turbine 3 away from the harmonic reducer 2; the photoelectric encoder 4 is driven by the turbine 3.

[0064] The turbine 3 is driven by gas. When the turbine 3 starts, the rotational motion is transmitted to the rigid wheel 21 through the harmonic reducer 2, causing the rigid wheel 21 to rotate. The rigid wheel 21 is threadedly connected to the output shaft 1. Under the limiting action of the harmonic reducer 2, the turbine 3 and the photoelectric encoder 4, the output shaft 1 cannot rotate. Therefore, under the action of the rotational motion of the rigid wheel 21, the output shaft 1 moves linearly.

[0065] In this application, the output shaft 1 is located at the center of the harmonic reducer 2, the turbine 3, and the photoelectric encoder 4, which can provide a more uniform load output. At the same time, compared with existing NMR-compatible cylinders, this application utilizes the overall volume and length of the harmonic reducer 2, the turbine 3, and the photoelectric encoder 4 to assemble a larger length output shaft 1 inside them. Furthermore, a larger output stroke can be achieved by changing the length of the output shaft 1. The torque, speed, and position of the motor can be controlled by controlling the magnitude of the input airflow, and a deeper level of dynamic model analysis can be performed. This has advantages in the precise control of position and speed and output force control of NMR-compatible robots.

[0066] This application combines the harmonic reducer 2 with the turbine 3, which can efficiently adjust the speed of motion. It has the characteristics of nuclear magnetic compatibility, low cost, and green environmental protection, and can be widely used in the medical field.

[0067] One embodiment of this application, such as Figure 1 As shown, at least one groove 10 is provided on the outer circumferential surface of the output shaft 1, and the groove 10 extends along the axial direction of the output shaft 1; a protrusion 5 is provided on the inner surface of the harmonic reducer 2 and / or the photoelectric encoder 4, and the protrusion 5 is slidably arranged in the groove 10.

[0068] Specifically, the protrusion 5 cooperates with the slide groove 10 to limit the sliding of the output shaft 1, so that when the turbine 3 is started, the output shaft 1 can move in a straight line without deflection.

[0069] In one embodiment of this invention, both the harmonic reducer 2 and the photoelectric encoder 4 have protrusions 5 on their inner surfaces to improve the smoothness of the linear movement of the output shaft 1.

[0070] In one embodiment of this invention, there are two slide grooves 10, which are symmetrically distributed radially along the output shaft 1, and the arrangement direction of the two slide grooves 10 is perpendicular to the moving direction of the output shaft 1. This makes the limiting effect of the protrusion 5 on the output shaft 1 more balanced, and further improves the stability of the linear movement of the output shaft 1.

[0071] One embodiment of this application, such as Figure 2 and Figure 3 As shown, the photoelectric encoder 4 includes: an encoder bracket 41, a fiber optic plug aligner 42, an encoder disk unit 43, and a gear transmission assembly 44; the encoder bracket 41 is sleeved on the output shaft 1; the output shaft 1 is slidable relative to the encoder bracket 41; the fiber optic plug aligner 42 is disposed on the encoder bracket 41 and is used to accommodate the encoder disk unit 43. Figure 3 As shown, the protrusion 5 is located on the inner circumferential surface of the encoder bracket 41.

[0072] The fiber optic plug aligner 42 has a light path, and its lower surface is recessed upwards to form a receiving groove 421, with the opening of the receiving groove 421 facing downwards. The light path communicates with the receiving groove 421. The encoder disk unit 43 is rotatably disposed within the receiving groove 421. The gear transmission assembly 44 is located within the encoder bracket 41 and is connected to both the turbine 3 and the encoder disk unit 43, thereby driving the encoder disk unit 43 to rotate under the drive of the turbine 3.

[0073] It should be noted that when the gear transmission assembly 44 drives the encoder disk unit 43 to rotate under the drive of the turbine 3, it will not cause adverse interference to the movement of the output shaft 1, so as to ensure that the output shaft 1 can move normally along a straight line.

[0074] Light can enter the photoelectric encoder 4 through the light path. When the turbine 3 starts, the gear transmission assembly 44 drives the encoder disk unit 43 to rotate, thereby blocking and avoiding the light passing through the light path by changing the position of the encoder disk unit 43 during rotation. Specifically, the encoder disk unit 43 is used to block the light path to make the light path open; the encoder disk unit 43 is also used to avoid the light path to make the light path open. That is, when the encoder disk unit 43 rotates, it can change the state of the light path back and forth between the open and closed states, thereby converting the optical information into electrical information through the photoelectric encoder 4, and finally realizing the acquisition of the rotation speed of the nuclear magnetic resonance compatible linear pneumatic motor.

[0075] The photoelectric encoder 4 also includes: two mounting hole units 45 and a ceramic core 46 (e.g., ...). Figure 2 and Figure 3 (As shown); the mounting hole unit 45 includes two mounting holes 450, as shown Figure 3 , Figure 4 , Figure 6 and Figure 7 As shown, two mounting holes 450 are symmetrically distributed on both sides of the receiving groove 421 and are located in a straight line; Figure 5 As shown, both mounting holes 450 extend into the receiving groove 421, so that the two mounting holes 450 cooperate with the receiving groove 421 to form the light path.

[0076] It is understood that each mounting hole unit 45 can form a light path. Since the photoelectric encoder includes two mounting hole units 45, two light paths can be formed within the photoelectric encoder (e.g., ...). Figures 8-14 As shown, the two light paths are the first light path 401 and the second light path 402, respectively.

[0077] One end of the ceramic core 46 is inserted into the mounting hole 450, and the ceramic core 46 is used to fix the optical fiber to conduct light to the optical path. The first optical path 401 and the second optical path 402 are both located on the rotation path of the encoding disk unit 43. When part of the structure of the encoding disk unit 43 rotates into the optical path, the optical path is blocked by the encoding disk unit 43, and the optical path changes from a conducting state to a blocked state; when the encoding disk unit 43 rotates to disengage from the optical path, the optical path changes from a blocked state to a conducting state.

[0078] The encoding disk unit 43 includes two encoding disks, such as... Figure 3 , Figure 6 and Figure 7 As shown, the encoders are a first encoder disk 431 and a second encoder disk 432. The first encoder disk 431 and the second encoder disk 432 are arranged coaxially and vertically. Two light paths correspond one-to-one with the two encoder disks: the first light path 401 corresponds to the first encoder disk 431 and is located on the rotation path of the corner of the first encoder disk 431; the second light path 402 corresponds to the second encoder disk 432 and is located on the rotation path of the corner of the second encoder disk 432. Furthermore, the two light paths are not coplanar, and the rotation center of the encoder disk unit 43 is located between the two light paths; that is, the first light path 401 and the second light path 402 are not coplanar, and the rotation center of the encoder disk unit 43 is located between the first light path 401 and the second light path 402.

[0079] When the turbine 3 is started, the encoder unit 43 rotates, the first encoder 431 and the second encoder 432 rotate synchronously, and the conduction and cut-off states of the two light paths are adjusted.

[0080] Specifically, such as Figure 6 and Figure 7 As shown, both the first encoding disk 431 and the second encoding disk 432 are pentagonal prism-shaped encoding disks. The second encoding disk 432 is located below the first encoding disk 431, and the second encoding disk 432 is rotated 162° relative to the center of the first encoding disk 431, such that the signal phase difference between the first encoding disk 431 and the second encoding disk 432 is 18° (e.g., ...). Figure 7 As shown), the states of the two light paths can be the same or different (e.g., both the first light path 401 and the second light path 402 can be in a conducting state, or both the first light path 401 and the second light path 402 can be in a disconnected state, or the first light path 401 can be in a conducting state while the second light path 402 can be in a disconnected state, or the first light path 401 can be in a disconnected state while the second light path 402 can be in a conducting state); when the encoding disk unit 43 rotates counterclockwise, the signal generated by the second encoding disk 432 lags behind the signal generated by the first encoding disk 431 by 18°; when the encoding disk unit 43 rotates clockwise, the signal generated by the second encoding disk 432 leads the signal generated by the first encoding disk 431 by 18°, thereby determining the rotation direction of the encoding disk unit 43 based on the change in the states of the two light paths. Furthermore, as the encoder unit 43 rotates, the states of the two light paths continuously switch. By determining whether the encoder unit 43 blocks the light path, the light signal is converted into an alternating bright and dark light pulse signal. Then, the light pulse signal can be converted into an electrical pulse signal through the photoelectric conversion circuit, thereby recording the number of pulses within a fixed time period and finally obtaining the rotational speed of the nuclear magnetic resonance compatible linear pneumatic motor.

[0081] like Figures 8-14 As shown in the figures, these are top views of the encoder disk unit 43 in its rotated state. The two light paths are distributed vertically as shown in the figures. The upper light path is the first light path 401, which corresponds to the first encoder disk 431; the lower light path is the second light path 402, which corresponds to the second encoder disk 432. In the initial state, as... Figure 8 As shown, both light paths are blocked; that is, the corner of the first encoder disk 431 is located on the first light path 401, and the corner of the second encoder disk 432 is simultaneously located on the second light path 402. Since the actual diameter of a laser beam is very small, both the first light path 401 and the second light path 402 are represented by dashed lines in the figure. Whenever the encoder disk touches a dashed line, it indicates that the light path is blocked.

[0082] In one embodiment of this example, when the encoding disk unit 43 changes from its initial state (e.g.) Figure 8 ,as well as Figure 19 As shown in Figure a, in the initial state, both the first light path 401 and the second light path 402 are in a blocked state, so both the first light path 401 and the second light path 402 output low-level signals. When the encoder disk unit 43 starts to rotate, as the encoder disk unit 43 rotates, the first light path 401 changes from a blocked state to a conducting state (e.g., ...). Figure 9 ,as well as Figure 19 As shown in Figure b, in this state, the first optical path 401 outputs a high-level signal) - conduction state (such as...) Figure 10 As shown, and Figure 19 As shown in Figure c, in this state, the first light path 401 outputs a high-level signal) - occlusion state (such as...) Figure 11 ,as well as Figure 19 As shown in Figure d, in this state, the first light path 401 outputs a low-level signal; the second light path 402 changes from the blocked state to the following states in sequence: blocked state (e.g., ... Figure 9 ,as well as Figure 19 As shown in Figure b, in this state, the second optical path 402 outputs a low-level signal - conduction state (e.g., Figure 10 ,as well as Figure 19 As shown in Figure c, in this state, the second optical path 402 outputs a high-level signal - conduction state (as shown in Figure c). Figure 11 ,as well as Figure 19 As shown in d, in this state, the second light path 402 outputs a high-level signal; then, the light path 401 corresponding to the first encoder disk 431 first changes from the blocked state to the open state, and the encoder disk unit 43 rotates counterclockwise.

[0083] In another embodiment of this example, when the encoding disk unit 43 changes from its initial state (e.g.) Figure 8 ,as well as Figure 20 As shown in Figure e, in the initial state, both the first light path 401 and the second light path 402 are in an obstructed state, so both the first light path 401 and the second light path 402 output low-level signals. When the encoder disk unit 43 starts to rotate, as the encoder disk unit 43 rotates, the first light path 401 changes from an obstructed state to an obstructed state in sequence: obstructed state (e.g., ... Figure 12 ,as well as Figure 20 As shown in Figure f, in this state, the first optical path 401 outputs a low-level signal - conduction state (e.g., Figure 13 ,as well as Figure 20 As shown in Figure g, in this state, the first optical path 401 outputs high and low level signals) - conduction state (e.g.) Figure 14 as well as Figure 20As shown in Figure h, in this state, the first optical path 401 outputs high and low level signals; the second optical path 402 changes from the blocked state to the conducting state in sequence (e.g., Figure 12 ,as well as Figure 20 As shown in Figure f, in this state, the second optical path 402 outputs a high-level signal - conduction state (as shown in Figure f). Figure 13 ,as well as Figure 20 As shown in g, in this state, the second light path 402 outputs a high-level signal) - occlusion state (such as...) Figure 14 ,as well as Figure 20 As shown in h, in this state, the second light path 402 outputs a low-level signal; then, the light path 402 corresponding to the second encoder disk 432 first changes from the blocked state to the open state, and the encoder disk unit 43 rotates clockwise.

[0084] One embodiment of this application, such as Figure 3 As shown, the gear transmission assembly 44 includes a first gear 441 and a second gear 442. The first gear 441 is coaxially arranged on the output shaft 1 and can rotate relative to the output shaft 1. The first gear 441 is driven by the turbine 3 to rotate relative to the output shaft 1 under the drive of the turbine 3. The second gear 442 meshes with the first gear 441 and is connected to the encoder disk unit 43, thereby driving the encoder disk unit 43 to rotate.

[0085] Specifically, both the first gear 441 and the second gear 442 are bevel gears. The outer diameter of the first gear 441 is larger than that of the second gear 442, and the axial direction of the second gear 442 is perpendicular to the axial direction of the first gear 441. The first gear 441 is coaxially arranged with the output shaft 1, and the second gear 442 is connected to the encoder disk unit 43 via a transmission shaft. The transmission shaft is coaxially arranged with the second gear 442, and one end of the transmission shaft is fixedly connected to the second gear 442, while the other end passes through the encoder bracket 41 and extends upward to be fixedly connected to the encoder disk unit 43, thereby realizing the transmission from the first gear 441 to the encoder disk unit 43.

[0086] When the turbine 3 starts, the first gear 441 rotates and transmits the rotational motion to the second gear 442, thereby driving the encoder disk unit 43 to rotate. When the photoelectric encoder 4 is in working condition, the two light paths alternately output light signals. Therefore, the photoelectric encoder 4 is an AB phase fiber optic encoder, and the rotation direction can be determined by which light path changes from no light signal to light signal first.

[0087] In one embodiment of this invention, the encoding disk unit 43 is positioned within the receiving groove 421 via a connecting shaft. Specifically, one end of the connecting shaft is connected to the fiber optic plug aligner 42, and the other end is connected to the encoding disk unit 43 via a first bearing 47. The top of the encoding disk unit 43 is recessed into a groove, and the first bearing 47 is located within this groove. The outer ring of the first bearing 47 is fitted to the inner wall of the groove; the inner ring of the first bearing 47 is sleeved on the connecting shaft. The drive shaft is connected to the encoding disk unit 43 via a second bearing 48; the outer ring of the second bearing 48 is fitted to the encoding disk unit 43, and the inner ring of the second bearing 48 is sleeved on the drive shaft.

[0088] One embodiment of this application, such as Figure 15 and Figure 16 As shown, the harmonic reducer 2 includes: a reducer fixing member 22, a flexible wheel 23, and a wave generator 24. The reducer fixing member 22 is sleeved on the output shaft 1, and the output shaft 1 is movable relative to the reducer fixing member 22; the rigid wheel 21 is rotatably connected to the reducer fixing member 22. The flexible wheel 23 is rotatably sleeved on the output shaft 1 and is drivenly connected to the turbine 3; the outer circumferential surface of the flexible wheel 23 is provided with gear teeth, and the inner circumferential surface of the rigid wheel 21 is provided with gear teeth; the flexible wheel 23 is located inside the rigid wheel 21 and meshes with the rigid wheel 21; the wave generator 24 is rotatably sleeved on the output shaft 1; the wave generator 24 is drivenly connected to the turbine 3 and cooperates with the inner circumferential surface of the flexible wheel 23 to drive the flexible wheel 23 to rotate. Figure 17 As shown, the protrusion 5 is located on the inner circumferential surface of the reducer fixing member 22.

[0089] The flexible wheel 23 is a thin-shell elastic element, thus it can undergo elastic deformation under the action of the wave generator 24. The wave generator 24 is embedded in the flexible wheel 23. When the wave generator 24 rotates under the drive of the turbine 3, the flexible wheel 23 changes from a circular shape to an elliptical shape, while the rigid wheel 21 remains unchanged. Therefore, for the deformed elliptical flexible wheel 23, a portion is fully engaged with the rigid wheel 21, and a portion is completely disengaged. Specifically, the teeth of the elliptical flexible wheel 23 near both ends of its major axis are fully engaged with the teeth of the rigid wheel 21, while the teeth of the elliptical flexible wheel 23 near both ends of its minor axis are completely disengaged from the rigid wheel 21. The remaining teeth of the flexible wheel 23 are in a transitional state between engagement and disengagement.

[0090] The wave generator 24 has multiple first receiving slots on its outer circumferential surface, and each first receiving slot is fitted with a sphere 231 (e.g., Figure 15 and Figure 16 (As shown); a second receiving groove is provided on the inner circumferential surface of the flexible wheel 23 corresponding to the sphere 231. The wave generator 24 is embedded in the flexible wheel 23, and the sphere 231 is placed in the corresponding first and second receiving grooves, thereby reducing the friction between the wave generator 24 and the flexible wheel 23 through the sphere 231. The rotation of the wave generator 24 will drive the flexible wheel 23 to continuously change its shape, so that the meshing state of the flexible wheel 23 and the rigid wheel 21 will also continuously change, from meshing, meshing, meshing out, disengaging, and meshing again, repeating cyclically, thereby realizing the transmission of motion.

[0091] The harmonic reducer 2 can achieve a high reduction ratio using simple parts, and has the advantages of high precision, high efficiency, and low noise.

[0092] One implementation method in this embodiment, such as Figure 15 As shown, a portion of the wave generator 24 is also nested within the rigid wheel 21, and a third bearing 25 is arranged between the wave generator 24 and the rigid wheel 21; a fourth bearing 26 is arranged between the rigid wheel 21 and the reducer fixing member 22, with the inner ring of the fourth bearing 26 sleeved on the rigid wheel 21 and the outer ring correspondingly assembled with the reducer fixing member 22.

[0093] One embodiment of this application, such as Figure 18 As shown, the turbine 3 includes a stator 31 and a rotor 32; the stator 31 is sleeved on the output shaft 1, and the output shaft 1 is movable relative to the stator 31; the rotor 32 is sleeved on the output shaft 1 and assembled inside the stator 31. Both ends of the rotor 32 extend outside the stator 31 and are respectively connected to the harmonic reducer 2 and the photoelectric encoder 4.

[0094] Specifically, both ends of the rotor 32 are connected to the wave generator 24 and the first gear 441 respectively, thereby driving the wave generator 24 and the first gear 441 to rotate. Multiple slots 321 are provided at both ends of the rotor 32, and multiple reinforcing ribs 6 are provided on the inner circumferential surfaces of the wave generator 24 and the first gear 441. The reinforcing ribs 6 cooperate with the slots 321 to reduce the interference between the rotor 32 and the wave generator 24 and the first gear 441, ensuring that the wave generator 24 and the first gear 441 can rotate synchronously with the rotor 32.

[0095] One implementation method in this embodiment, such as Figure 18 As shown, a fifth bearing 33 is arranged between the rotor 32 and the stator 31.

[0096] In one embodiment of this application, the reduction ratio of the harmonic reducer 2 is 1:20, and the lead of the output shaft 1 is 3 mm / r. Therefore, for every one revolution of the rotor 32, the output shaft 1 advances 0.15 mm. The reduction ratio of the first gear 441 and the second gear 442 is 2:1. For every one revolution of the rotor 32, the encoder disk unit 43 rotates twice. Therefore, for every one revolution of the rotor 32, the photoelectric encoder 4 can provide 40 count values. For the NMR-compatible linear pneumatic motor provided in this application, the photoelectric encoder 4 can provide a resolution of less than 0.01 mm.

[0097] In summary, this application provides a nuclear magnetic resonance compatible linear pneumatic motor, comprising: an output shaft having an external thread and located at the center of the linear pneumatic motor; a harmonic reducer; the harmonic reducer including a rigid wheel, the rigid wheel being sleeved on the output shaft and threadedly connected to the output shaft; a turbine, sleeved on the output shaft and located on one side of the harmonic reducer; the turbine being drivenly connected to the rigid wheel and used to drive the rigid wheel to rotate, thereby driving the output shaft to move linearly along the axial direction; and a photoelectric encoder, sleeved on the output shaft and located on the side of the turbine away from the harmonic reducer; the photoelectric encoder being drivenly connected to the turbine. The output shaft described in this application is located at the center of the linear pneumatic motor, resulting in uniform force load. Furthermore, compared to existing NMR-compatible cylinders, this application utilizes the overall volume and length of the harmonic reducer, the turbine, and the photoelectric encoder to assemble a larger output shaft internally. Moreover, a greater output stroke can be achieved by changing the length of the output shaft. The torque, speed, and position of the motor can be controlled by adjusting the input airflow, which facilitates deeper dynamic model analysis.

[0098] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A nuclear magnetic compatible linear pneumatic motor, characterized by, It includes: The output shaft has an external thread and is located at the center of the linear pneumatic motor; Harmonic reducer; the harmonic reducer includes a rigid wheel, which is sleeved on the output shaft and threadedly connected to the output shaft; A turbine is mounted on the output shaft and located on one side of the harmonic reducer; the turbine is connected to the rigid wheel drive and is used to drive the rigid wheel to rotate, so as to drive the output shaft to move linearly along the axial direction; An optical encoder is sleeved on the output shaft and located on the side of the turbine away from the harmonic reducer; the optical encoder is connected to the turbine in a driving connection. At least one groove is provided on the outer circumferential surface of the output shaft, and the groove extends along the axial direction of the output shaft. The inner surface of the harmonic reducer and / or the photoelectric encoder is provided with a protrusion, which is slidably arranged in the groove. The photoelectric encoder includes: An encoder bracket is fitted onto the output shaft; the output shaft is slidable relative to the encoder bracket. A fiber optic plug aligner is mounted on the encoder bracket; the fiber optic plug aligner is provided with a light path and a receiving slot; the light path is connected to the receiving slot. The encoding disk unit is rotatably disposed within the receiving slot; the encoding disk unit is used to block light so that the light path is in a disconnected state; the encoding disk unit is also used to avoid light so that the light path is in a conductive state; A gear transmission assembly is located inside the encoder bracket and is connected to the turbine and the encoder disk respectively, so as to drive the encoder disk to rotate under the drive of the turbine.

2. The nuclear magnetic compatible linear pneumatic motor of claim 1, wherein, There are two slides, which are symmetrically distributed radially along the output shaft.

3. The nuclear magnetic compatible linear pneumatic motor of claim 1, wherein, The photoelectric encoder also includes: Two mounting hole units; each mounting hole unit includes two mounting holes, which are symmetrically distributed along a straight line on both sides of the receiving groove and extend into the receiving groove to form a light path; A ceramic core is located within the mounting hole and is used to fix the optical fiber; The two light paths are not arranged in the same plane, and the rotation center of the encoder disk unit is located between the two light paths.

4. The nuclear magnetic compatible linear pneumatic motor of claim 3, wherein, The encoding disk unit includes: The first encoding disk is in the shape of a pentagonal prism; in the two light paths, one light path corresponds to the first encoding disk and is located on the rotation path of the corner of the first encoding disk; The second encoding disk is in the shape of a pentagonal prism; in the two light paths, the other light path corresponds to the second encoding disk and is located on the rotation path of the corner of the second encoding disk; The first encoding disk and the second encoding disk are coaxial and arranged in the vertical direction; the second encoding disk is rotated 162° relative to the center of the first encoding disk.

5. The nuclear magnetic compatible linear pneumatic motor of claim 4, wherein, The on and off states of the two light paths can be the same or different to determine the rotation direction of the encoder disk unit.

6. The nuclear magnetic compatible linear pneumatic motor of claim 1, wherein, The gear transmission assembly includes: The first gear is coaxially arranged on the output shaft and is connected to the turbine for transmission, so as to rotate relative to the output shaft under the drive of the turbine; The second gear meshes with the first gear and is connected to the encoder disk unit; the axial direction of the second gear is perpendicular to the axial direction of the first gear.

7. The nuclear magnetic compatible linear pneumatic motor of claim 1, wherein, The harmonic reducer includes: A reducer fixing component is sleeved on the output shaft; the rigid wheel is rotatably connected to the reducer fixing component; A flexible wheel is rotatably mounted on the output shaft and is connected to the turbine for transmission; the flexible wheel is located inside the rigid wheel and meshes with the rigid wheel; A wave generator is rotatably mounted on the output shaft; the wave generator is connected to the turbine and engages with the inner circumferential surface of the flexible wheel to drive the flexible wheel to rotate.

8. The nuclear magnetic compatible linear pneumatic motor of claim 1, wherein, The turbine includes: The stator is fitted onto the output shaft; The rotor is sleeved on the output shaft and assembled inside the stator; both ends of the rotor extend outside the stator and are respectively connected to the harmonic reducer and the photoelectric encoder.

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