Radiation therapy equipment, range adjusters and linear actuators

Abstract

The present invention belongs to the technical field of high-end medical equipment, and discloses a radiotherapy device, a range adjuster and a linear actuator. The linear actuator includes: at least one group of transmission modules, the transmission module includes at least two transmission rollers, a support block and a clamping block, the transmission roller includes a transmission screw and a bearing, each transmission screw is arranged non-parallel to the axis of the actuating optical axis and clamped on the actuating optical axis, so that the transmission module has a load along the axis direction of the actuating optical axis and is used to drive the driven object to move linearly along the axis direction of the actuating optical axis, and there is a threadless connection between the transmission screw and the actuating optical axis. When the load on the transmission module exceeds a threshold value, the transmission screw slides on the actuating optical axis, thereby realizing overload protection, avoiding the transmission module and the actuating optical axis from being worn or even damaged due to impact force. By matching the spherical bearing with the grooves on the support block and the clamping block, the angle range between the transmission screw and the actuating optical axis can be increased.

Description

[0001] This application is a divisional application of the original application with application number CN202410623158.8 (the application date is May 20, 2024, and the name of the invention is radiotherapy equipment, range adjuster and linear actuator). Technical Field

[0002] The present invention relates to the technical field of high-end medical equipment, and in particular to radiotherapy equipment, a range adjuster and a linear actuator. Background Art

[0003] With the advancement of medical technology, compared with traditional treatment methods such as surgery, chemotherapy, and X-ray radiotherapy, proton radiotherapy can provide more accurate and effective treatment, reduce side effects during treatment, and thus improve the quality of life of patients. Among them, the range shifter is the core component of the compact proton therapy system to achieve proton beam energy adjustment during proton therapy for patients. In the compact proton therapy system, the energy switching speed of the range shifter is required to be as fast as possible, and the position control accuracy is safe and reliable. This requires fast and accurate control of the range adjustment plate. In order to further improve the position control accuracy of the range adjustment plate, it is necessary to design a new type of range shifter. Summary of the invention

[0004] The object of the present invention is to provide a radiotherapy device, a range adjuster and a linear actuator for ensuring accurate control of a range adjustment plate.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] The present invention provides a linear actuator, comprising: at least one group of transmission modules for driving a driven object to move along a linear direction, the transmission module being sleeved on an actuating optical shaft for realizing rotational motion, the transmission module comprising at least two transmission rollers, a support block and a clamping block, the transmission roller comprising a transmission screw and bearings respectively arranged at both ends of the transmission screw for cooperating with the support block and the clamping block, each of the transmission screws being arranged non-parallel to the axis of the actuating optical shaft, the transmission screw and the actuating optical shaft being connected without threads, at least two of the transmission screws being clamped on the actuating optical shaft, so that the transmission module is used to drive the driven object to move linearly along the axis of the actuating optical shaft when there is a load along the axis of the actuating optical shaft and the load does not exceed a threshold value, and the two transmission screws are non-parallel to each other and are located on both sides of the axis of the actuating optical shaft; the transmission module is configured such that when the load received exceeds the threshold value, the transmission roller is used to slide on the actuating optical shaft.

[0007] Preferably, the transmission module includes a first transmission module, the first transmission module includes at least two first transmission rollers, a first support block and a first clamping block, the first support block has a first bottom wall and a first side wall, the first bottom wall and the first side wall are surrounded to form a first accommodating space, the first transmission roller and the first clamping block are arranged in the first accommodating space, the first clamping block is fixedly connected to the first side wall by a first fastener, and the size of the load of the first transmission module is controlled by adjusting the distance from the first clamping block to the first bottom wall;

[0008] The first transmission roller includes a first transmission screw and a first bearing and a second bearing respectively arranged at both ends of the first transmission screw. The first transmission screw is clamped on the actuating optical axis. The first bottom wall is provided with a first groove for accommodating at least part of the first bearing. The first clamping block is provided with a second groove for accommodating at least part of the second bearing.

[0009] Preferably, the transmission module further comprises a second transmission module, the second transmission module comprises at least two second transmission rollers, a second support block and a second clamping block, the second support block has a second bottom wall and a second side wall, the second bottom wall and the second side wall are surrounded to form a second accommodating space, the second transmission roller and the second clamping block are arranged in the second accommodating space, the second clamping block is fixedly connected to the second side wall by a second fastener, and the size of the load of the second transmission module is controlled by adjusting the distance from the second clamping block to the second bottom wall;

[0010] The second transmission roller includes a second transmission screw and a third bearing and a fourth bearing respectively arranged at both ends of the second transmission screw, the second transmission screw is clamped on the actuating optical axis, the second bottom wall is provided with a third groove for accommodating at least part of the third bearing, and the second clamping block is provided with a fourth groove for accommodating at least part of the fourth bearing.

[0011] Preferably, the transmission module further comprises a connecting block, and the first bottom wall and the second bottom wall are respectively arranged at two ends of the connecting block and are respectively fixedly connected to the two ends of the connecting block through a third fastener.

[0012] A range adjuster, comprising:

[0013] A range adjustment plate, wherein the range adjustment plate is used for allowing the particle beam to pass through;

[0014] A motion control mechanism, the motion control mechanism includes a drive device and a motion controller, the motion controller is used to control the drive device, the drive device includes a drive motor and a linear actuator as described in any one of the above items, the drive device is used to drive the range adjustment plate to move the range adjustment plate into or out of the travel path of the particle beam to adjust the thickness of the range adjustment plate through which the particle beam passes.

[0015] Preferably, one linear actuator is respectively provided on both sides of the range adjustment plate, and the linear actuators on both sides of the range adjustment plate are not aligned along the width direction of the range adjustment plate.

[0016] Preferably, it also includes a frame, the driving device is arranged on two opposite sides of the frame, the two ends of the actuating optical axis are respectively arranged at two opposite ends of the frame, the driving motor is arranged at one end of the actuating optical axis, and the linear actuator is connected to the range adjustment plate and sleeved on the actuating optical axis.

[0017] Preferably, the motion control mechanism further comprises a first position sensor, the first position sensor is connected to the drive motor, and the first position sensor is used to detect the rotational motion of the drive motor to obtain the position information of the range adjustment plate; and / or,

[0018] The motion control mechanism further includes a second position sensor, the second position sensor is connected to the linear actuator, and the second position sensor is used to detect the position of the linear actuator to obtain the position information of the range adjustment plate; and / or,

[0019] The motion control mechanism further includes a third position sensor, which is disposed near two opposite ends of the frame to limit the motion range of the linear actuator.

[0020] Preferably, the second position sensor is arranged on the frame, an elastic plunger connected to the second position sensor is arranged on the linear actuator, and the second position sensor obtains the position information of the range adjustment plate through the position of the elastic plunger on the second position sensor; and / or,

[0021] The motion control mechanism further includes a circuit board, the first position sensor, the second position sensor, the third position sensor and the drive motor are all connected to the circuit board, and the circuit board is connected to the motion controller.

[0022] Preferably, it also includes a plurality of slide rails and adjustment brackets, wherein the slide rails are arranged corresponding to the actuating optical axes one by one, the range adjustment plate is arranged on the adjustment bracket, one end of the adjustment bracket is connected to the linear actuator, and the other end of the adjustment bracket is connected to the slide rail.

[0023] Preferably, it further comprises a limiting device, which is respectively arranged at two opposite ends of the frame, and is used to limit the range of movement of the range adjustment plate; or,

[0024] There are a plurality of range adjustment plates, and gaps are left between adjacent range adjustment plates so that the movements of each range adjustment plate will not interfere with or affect each other.

[0025] Preferably, buffer members are provided at both ends of the adjustment bracket facing the limiting device.

[0026] A radiotherapy device comprises a treatment frame, a particle accelerator, a scanning magnet, an ionization chamber and a range adjuster as described in any one of the above.

[0027] The radiotherapy device, range adjuster and linear actuator of the present invention have at least the following advantages:

[0028] The radiotherapy equipment, range adjuster and linear actuator of the present invention are clamped on the actuating optical axis by the transmission screw of the transmission roller, so that the transmission module has a load, that is, bears the load, and then the transmission module drives the range adjustment plate to move. By setting the bearing as a spherical or a part of a spherical shape, the support block and the clamping block are provided with grooves that match the bearing. When the angle between the transmission screw and the actuating optical axis changes, the bearing slides more smoothly, and the spherical bearing can increase the angle range between the transmission screw and the actuating optical axis, thereby increasing the load range of the transmission module. Since there is no threaded connection between the transmission screw and the actuating optical axis, but the transmission screw is clamped on the actuating optical axis, the transmission module can drive the object to be transmitted to move in a linear direction. When the load on the transmission module exceeds the threshold, the transmission screw slides on the actuating optical shaft, thereby achieving overload protection and preventing the transmission module and the actuating optical shaft from being worn or even damaged due to impact force. This not only extends the service life of the transmission module and the actuating optical shaft, thereby extending the service life of the linear actuator, but also ensures the accuracy of the linear actuator's movement, thereby ensuring precise control of the range adjustment plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of a linear actuator according to an embodiment of the present invention.

[0030] Figure 2 Schematic diagram of an exploded view of a linear actuator according to an embodiment of the present invention.

[0031] Figure 3 It is a perspective structural diagram of a range adjuster according to an embodiment of the present invention.

[0032] Figure 4 2 is a schematic diagram of the structure of the range adjuster according to another perspective of the embodiment of the present invention.

[0033] Figure 5 It is an exploded schematic diagram of a range adjustment plate and an adjustment bracket according to an embodiment of the present invention.

[0034] Figure 6 This is a comparison diagram of the total thickness of the range adjustment plates required when the particle beam according to the embodiment of the present invention passes through the range adjustment plates of different materials for energy reduction.

[0035] Figure 7 This is a comparison diagram of the beam spot sizes formed when the particle beam according to an embodiment of the present invention passes through range adjustment plates made of different materials.

[0036] In the figure: 100, range adjuster; 1, range adjustment plate; 2, motion control mechanism; 21, driving device; 211, driving motor; 212, actuating optical axis; 2121, third end; 2122, fourth end; 213, linear actuator; 2131, first transmission module; 21311, first transmission roller; 213111, first transmission screw; 213112, first bearing; 213113, second bearing; 21312, first support block; 213121, first bottom wall; 213122, first side wall; 213123, first accommodating space; 213124, first groove; 21313, first clamping block; 213131, second groove; 21314, first fastener; 2132, second transmission module; 21321, second transmission roller; 213211, second transmission screw; 213212 , third bearing; 213213, fourth bearing; 21322, second support block; 213221, second bottom wall; 213222, second side wall; 213223, second accommodating space; 213224, third groove; 21323, second clamping block; 213231, fourth groove; 21324, second fastener; 2133, connecting block; 21331, fifth groove; 21332, third fastener; 2134, elastic plunger; 2135, sensing part; 2136, through hole; 22, first position sensor; 23, second position sensor; 24, third position sensor; 25, motion controller; 26, circuit board; 3, rack; 31, first end; 32, second end; 33, first side; 34, second side; 4, slide rail; 5, adjustment bracket; 51, hollow part; 52, clamping structure; 6, limit device. DETAILED DESCRIPTION

[0037] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete and to fully convey the concepts of example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their repeated description will be omitted.

[0038] The words expressing positions and directions described in the present invention are all explained with reference to the accompanying drawings as examples, but they can be changed as needed, and all such changes are included in the protection scope of the present invention.

[0039] Reference Figure 1 to Figure 2 The present invention provides a linear actuator 213, comprising: at least one transmission module for driving a transmission object to move in a linear direction, one end of the transmission module can be connected to the range adjustment plate 1, the transmission module is sleeved on the actuation optical axis 212 and can move along the axial direction of the actuation optical axis 212 and move with the range adjustment plate 1. The transmission object can be the range adjustment plate 1.

[0040] Specifically, the linear actuator 213 may include one or more transmission modules, and the transmission modules are used to drive the transmitted object to move in a linear direction. The multiple transmission modules increase the contact points or contact areas with the actuating optical axis 212, which can not only improve the load capacity of the linear actuator 213, but also improve the stability between the linear actuator 213 and the actuating optical axis 212. At the same time, since the contact points or contact areas with the actuating optical axis 212 are increased, the pressure at the contact points or contact areas can be reduced, thereby reducing the wear between the transmission module and the actuating optical axis 212, thereby extending the service life of the transmission module and the actuating optical axis 212 and improving the accuracy of the relative movement of the transmission module and the actuating optical axis 212.

[0041] Each group of transmission modules may include at least two transmission rollers, a support block and a clamping block. Each transmission roller is arranged non-parallel to the axis of the actuating optical axis 212. The two ends of the transmission roller are respectively connected to the support block and the clamping block to achieve sliding cooperation between the two ends of the transmission roller and the support block and the clamping block. There is a non-threaded connection between the transmission roller and the actuating optical axis, that is, the transmission roller is arranged between the support block and the clamping block. The two transmission rollers can be roughly distributed in an X shape. The two transmission rollers cooperate with each other and are clamped on the actuating optical axis 212 so that the transmission module has a load along the axial direction of the actuating optical axis 212 and is used to drive the transmitted object to move linearly along the axial direction of the actuating optical axis 212. The support block and the clamping block are both provided with a through hole 2136 for the actuating optical axis 212 to pass through in a linear direction. The two transmission rollers are not parallel to each other and are located on both sides of the axis of the actuating optical axis 212. That is to say, the two transmission rollers are clamped on the actuating optical axis 212, and there is a certain holding force between the transmission rollers and the actuating optical axis 212, so that friction is generated between the transmission rollers and the actuating optical axis 212. The friction can not only keep the position between the transmission rollers and the actuating optical axis 212 stable, but also when the actuating optical axis 212 rotates, due to the friction between the transmission rollers and the actuating optical axis 212, the actuating optical axis 212 converts the friction into a thrust on the transmission rollers, so that the transmission rollers can move along the axial direction of the actuating optical axis 212, that is, the axial direction, and then drive the range adjustment plate 1 to move along the axial direction of the actuating optical axis 212. The clamping block can be set in the shape of a circular gear.

[0042] The transmission roller and the actuating optical axis 212 are preferably made of wear-resistant, high-hardness materials. The material of the actuating optical axis 212 is preferably spring steel, and the surface hardness is preferably above HRC58, so as to extend the service life of the transmission roller and the actuating optical axis 212, thereby avoiding the equipment from not being able to operate normally due to the wear of the transmission roller and the actuating optical axis 212. At the same time, the surfaces of the transmission roller and / or the actuating optical axis 212 are preferably made of materials with a high friction coefficient, which not only ensures that the transmission module has a load, but also makes the position between the transmission roller and the actuating optical axis 212 more stable.

[0043] In this embodiment, refer to Figure 2 Each transmission module group includes four transmission rollers, which are evenly distributed around the actuating optical axis 212 and clamped on the actuating optical axis 212, and each transmission roller is arranged non-parallel to the axis of the actuating optical axis 212, that is, each transmission roller is arranged crosswise with the actuating optical axis 212, and the axis of each transmission roller and the actuating optical axis 212 can be roughly distributed in an X shape. The four transmission rollers can improve the friction and stability between the transmission module and the actuating optical axis 212.

[0044] The linear actuator 213 of the present application is clamped on the actuating optical axis 212 through the transmission roller of the transmission module, so that the transmission module has a load, and the transmission module can drive the range adjustment plate 1 to move. Since there is no threaded connection between the transmission roller and the actuating optical shaft 212, but the transmission roller is clamped on the actuating optical shaft 212, that is, when the load on the transmission module does not exceed the threshold, the friction between the transmission roller and the actuating optical shaft 212 is used to achieve connection and relative movement, and the transmission roller is used to transmit the driving force in the axial direction on the actuating optical shaft 212 through the static friction between the transmission roller and the actuating optical shaft 212, thereby driving the transmission module to move axially; when the load on the transmission module exceeds the threshold, the transmission roller slides on the actuating optical shaft 212, thereby achieving overload protection, avoiding the transmission module and the actuating optical shaft 212 from being worn or even damaged due to impact force, not only extending the service life of the transmission module and the actuating optical shaft 212, and thus extending the service life of the linear actuator 213, but also ensuring the accuracy of the movement of the linear actuator 213, thereby ensuring the precise control of the range adjustment plate 1.

[0045] In a specific embodiment, referring to Figure 2 The transmission module may include a first transmission module 2131. The first transmission module 2131 may include at least two first transmission rollers 21311, a first support block 21312 and a first clamping block 21313. In this embodiment, there are four first transmission rollers 21311. The first support block 21312 is roughly a rectangular parallelepiped, more specifically, the first support block 21312 is a rectangular parallelepiped with an opening. Specifically, the first support block 21312 has a first bottom wall 213121 and a plurality of first side walls 213122, the number of the first bottom wall 213121 is one, the first bottom wall 213121 and the first side wall 213122 are arranged to form a first accommodating space 213123, the first transmission roller 21311 and the first clamping block 21313 are preferably arranged in the first accommodating space 213123, the first clamping block 21313 can be fixedly connected to the first side wall 213122 by a first fastener 21314, and the size of the load of the first transmission module 2131 can be controlled by adjusting the distance from the first clamping block 21313 to the first bottom wall 213121. Adjusting the distance from the first clamping block 21313 to the first bottom wall 213121 can change the angle between the first transmission roller 21311 and the actuating optical axis 212, that is, by changing the angle between the first transmission roller 21311 and the actuating optical axis 212, the load of the first transmission module 2131 can be changed. The projection of the two first transmission rollers 21311 along the axis direction perpendicular to the actuating optical axis 212 is in an X shape.

[0046] When the distance from the first clamping block 21313 to the first bottom wall 213121 is reduced, the angle between the first transmission roller 21311 and the actuating optical axis 212 increases, and the friction between the first transmission roller 21311 and the actuating optical axis 212 increases, thereby increasing the load of the first transmission module 2131. When the distance from the first clamping block 21313 to the first bottom wall 213121 is increased, the angle between the first transmission roller 21311 and the actuating optical axis 212 decreases, and the friction between the first transmission roller 21311 and the actuating optical axis 212 decreases, thereby reducing the load of the first transmission module 2131.

[0047] There are multiple first fasteners 21314 evenly distributed on the first side wall 213122, so that the first clamping block 21313 is more evenly stressed, so that the position of the first clamping block 21313 is more stable, so as to ensure the stability of the position of the first transmission roller 21311, and further ensure the stability of the load of the first transmission module 2131. The first fastener 21314 is against the gear of the first clamping block 21313.

[0048] The first transmission roller 21311 may include a first transmission screw 213111 and a first bearing 213112 and a second bearing 213113 respectively disposed at both ends of the first transmission screw 213111. The first transmission screw 213111 is clamped on the actuating optical axis 212. The first bottom wall 213121 is provided with a first groove 213124 for accommodating at least part of the first bearing 213112. The first clamping block 21313 is provided with a second groove 213131 for accommodating at least part of the second bearing 213113. The first bearing 213112 and the first groove 213124 are preferably slidably connected, and the second bearing 213113 and the second groove 213131 are preferably slidably connected. When the distance from the first clamping block 21313 to the first bottom wall 213121 changes, the angle between the first transmission roller 21311 and the actuating optical axis 212 can be changed. The first bearing 213112 and the second bearing 213113 are spherical bearings.

[0049] The first bearing 213112 and the second bearing 213113 are preferably spherical or part of a sphere, and the shapes of the first groove 213124 and the second groove 213131 match the first bearing 213112 and the second bearing 213113. When the angle between the first transmission roller 21311 and the actuating optical axis 212 changes, the first bearing 213112 and the second bearing 213113 slide more smoothly, and the spherical bearing can increase the angle range between the first transmission roller 21311 and the actuating optical axis 212.

[0050] Reference Figure 2The transmission module may further include a second transmission module 2132. The second transmission module 2132 may include at least two second transmission rollers 21321, a second support block 21322, and a second clamping block 21323. In this embodiment, there are four second transmission rollers 21321. The second support block 21322 is roughly a rectangular parallelepiped, and more specifically, the second support block 21322 is a rectangular parallelepiped with an opening. Specifically, the second support block 21322 has a second bottom wall 213221 and a second side wall 213222, the number of the second bottom wall 213221 is one, the second bottom wall 213221 and the second side wall 213222 are arranged to form a second accommodating space 213223, the second transmission roller 21321 and the second clamping block 21323 are preferably arranged in the second accommodating space 213223, the second clamping block 21323 can be fixedly connected to the second side wall 213222 by a second fastener 21324, and the size of the load of the second transmission module 2132 can be controlled by adjusting the distance from the second clamping block 21323 to the second bottom wall 213221. Adjusting the distance from the second clamping block 21323 to the second bottom wall 213221 can change the angle between the second transmission roller 21321 and the actuating optical axis 212. In other words, by changing the angle between the second transmission roller 21321 and the actuating optical axis 212, the load of the second transmission module 2132 can be changed.

[0051] When the distance from the second clamping block 21323 to the second bottom wall 213221 is reduced, the angle between the second transmission roller 21321 and the actuating optical axis 212 increases, and the friction between the second transmission roller 21321 and the actuating optical axis 212 increases, thereby increasing the load of the second transmission module 2132. When the distance from the second clamping block 21323 to the second bottom wall 213221 is increased, the angle between the second transmission roller 21321 and the actuating optical axis 212 decreases, and the friction between the second transmission roller 21321 and the actuating optical axis 212 decreases, thereby reducing the load of the second transmission module 2132.

[0052] The second fasteners 21324 are multiple and evenly distributed on the second side wall 213222, so that the second clamping block 21323 is more evenly stressed, so that the position of the second clamping block 21323 is more stable, so as to ensure the stability of the position of the second transmission roller 21321, and further ensure the stability of the load of the second transmission module 2132. The second fasteners 21324 are against the gear of the second clamping block 21323.

[0053] The second transmission roller 21321 may include a second transmission screw 213211 and a third bearing 213212 and a fourth bearing 213213 respectively disposed at both ends of the second transmission screw 213211, the second transmission screw 213211 is clamped on the actuating optical axis 212, the second bottom wall 213221 is provided with a third groove 213224 for accommodating at least part of the third bearing 213212, and the second clamping block 21323 is provided with a fourth groove 213231 for accommodating at least part of the fourth bearing 213213. The third bearing 213212 and the third groove 213224 are preferably slidably connected, and the fourth bearing 213213 and the fourth groove 213231 are preferably slidably connected. When the distance from the second clamping block 21323 to the second bottom wall 213221 changes, the angle between the second transmission roller 21321 and the actuating optical axis 212 can be changed. The third bearing 213212 and the fourth bearing 213213 are spherical bearings.

[0054] The third bearing 213212 and the fourth bearing 213213 are preferably spherical or part of a sphere, and the shapes of the third groove 213224 and the fourth groove 213231 match the third bearing 213212 and the fourth bearing 213213. When the angle between the second transmission roller 21321 and the actuating optical axis 212 changes, the third bearing 213212 and the fourth bearing 213213 slide more smoothly, and the spherical bearing can increase the angle range between the second transmission roller 21321 and the actuating optical axis 212.

[0055] As a preferred embodiment, the transmission module may further include a connecting block 2133, wherein the first bottom wall 213121 and the second bottom wall 213221 are respectively arranged at two ends of the connecting block 2133, and are respectively fixedly connected to the two ends of the connecting block 2133 by a third fastener 21332. In this way, the first transmission module 2131, the second transmission module 2132 and the connecting block 2133 are formed as a whole, and the connection between the transmission module and the range adjustment plate 1 is more stable.

[0056] The aperture of the first groove 213124 is preferably larger than that of the second groove 213131, and the aperture of the third groove 213224 is preferably larger than that of the fourth groove 213231. The fifth groove 21331 is provided on both sides of the connecting block 2133 facing the first bottom wall 213121 and the second bottom wall 213221. Part of the first bearing 213112 can protrude from the first groove 213124 and be provided in the fifth groove 21331, and part of the third bearing 213212 can protrude from the third groove 213224 and be provided in the fifth groove 21331. In this way, the connection between the first transmission module 2131, the second transmission module 2132 and the connecting block 2133 is more stable.

[0057] Reference Figures 1 to 5 The present invention further provides a range adjuster 100, comprising: a plurality of range adjustment plates 1 and a motion control mechanism 2, wherein the motion control mechanism 2 is used to adjust the position of the range adjustment plates 1, and the motion control mechanism 2 comprises the linear actuator 213 as described above.

[0058] The shape of the range adjustment plate 1 is, for example, a quadrilateral, a triangle, a circle or other polygons, etc. In the present embodiment, the shape of the range adjustment plate 1 is a rectangle. The range adjustment plate 1 is used for allowing a particle beam (not shown) to pass through, and the surfaces of the plurality of range adjustment plates 1 are arranged perpendicular to the traveling direction of the particle beam, that is, the thickness extension direction of the range adjustment plate 1 is parallel to the traveling direction of the particle beam, so that the particle beam passes through the range adjustment plate 1, and the particle beam may be a proton beam, and the material of the range adjustment plate 1 may be boron carbide, boron-containing polyethylene or boron-containing polypropylene.

[0059] Boron-containing polyethylene or boron-containing polypropylene material has the advantages of good light transmittance, light weight and heat resistance, plasticity, strong corrosion resistance, good wear resistance, high impact resistance and low price. Boron-containing polyethylene or boron-containing polypropylene material has good light transmittance, can effectively allow the particle beam to pass through the range adjustment plate 1, and will not scatter or absorb the particle beam too much, ensuring the high efficiency of the particle beam transmission of the radiotherapy equipment. The range adjustment plate 1 made of boron-containing polyethylene or boron-containing polypropylene material can reduce the scattering of the particle beam, keep the increase of the beam spot of the particle beam small, and keep the beam spot of the particle beam as small as possible, thereby ensuring that the particle beam reaches the affected area stably and accurately with a smaller beam spot.

[0060] The boron-containing polyethylene or boron-containing polypropylene material has a lower density, so that the overall weight of the range adjuster 100 is smaller and occupies less space, thereby reducing the weight and volume of the radiotherapy equipment.

[0061] Boron-containing polyethylene or boron-containing polypropylene material has high heat resistance, and the range adjustment plate 1 can withstand high temperature during the use of the radiotherapy equipment, thereby extending the service life of the range adjustment plate 1. At the same time, the performance of the range adjustment plate 1 can also remain stable, thereby extending the service life of the radiotherapy equipment and maintaining the performance of the radiotherapy equipment stable.

[0062] Boron-containing polyethylene or boron-containing polypropylene material has good plasticity, and can be made into range adjustment plates 1 of various shapes and sizes by heating and pressing to meet the needs of different radiotherapy equipment. Boron-containing polyethylene or boron-containing polypropylene material range adjustment plate 1 is easy to manufacture, which reduces the manufacturing cost, and the thickness consistency of the range adjustment plate 1 is good, which can ensure the adjustment performance of different positions of the range adjustment plate 1 is consistent, and improve the stability of the performance of the range adjustment plate 1. At the same time, the flatness of the range adjustment plate 1 is high, and the range adjustment plate 1 not only moves more smoothly, but also can ensure the adjustment performance of different positions of the range adjustment plate 1 is consistent, and improve the stability of the performance of the range adjustment plate 1.

[0063] Boron-containing polyethylene or boron-containing polypropylene material has good corrosion resistance to common chemicals such as acid and alkali, and the range adjustment plate 1 is not easily affected by the external environment, and the range adjustment plate 1 can maintain a relatively long service life.

[0064] Boron-containing polyethylene or boron-containing polypropylene has good wear resistance and impact resistance. The range adjustment plate 1 needs to be moved frequently during use. The range adjustment plate 1 made of boron-containing polyethylene or boron-containing polypropylene has good wear resistance, which can extend the service life of the range adjustment plate 1 and ensure that the performance of the range adjustment plate 1 remains highly stable during use. The range adjustment plate 1 may also experience unexpected situations such as collisions during installation or use. The range adjustment plate 1 made of boron-containing polyethylene or boron-containing polypropylene has good impact resistance, which extends the service life of the range adjustment plate 1 and prevents the range adjustment plate 1 from being damaged by external impact.

[0065] Multiple range adjustment plates 1 are arranged parallel to each other, which not only ensures that a fixed distance is maintained between adjacent range adjustment plates 1 to prevent adjacent range adjustment plates 1 from colliding during movement, but also prevents the particle beam from scattering or changing its direction when passing through the parallel range adjustment plates 1, thereby ensuring that the particle beam reaches the affected area stably and accurately with a smaller beam spot.

[0066] Gaps (not shown) are left between adjacent range adjustment plates 1 so that the movement of each range adjustment plate 1 will not interfere with or affect each other, ensuring smooth operation of the range adjustment plate 1 and avoiding jamming, and also improving the accuracy of position adjustment of the range adjustment plate 1.

[0067] The motion control mechanism 2 includes a plurality of driving devices 21 and a motion controller 25. The driving devices 21 and the motion controller 25 may be connected by wires or wirelessly. The motion controller 25 is used to control the driving devices 21. Each driving device 21 may include a driving motor 211, an actuating optical axis 212, and the above-mentioned linear actuator 213. The driving devices 21 are used to drive the range adjustment plate 1 to move. The driving devices 21 are used to move the range adjustment plate 1 into or out of the path of travel of the particle beam to adjust the total thickness of the range adjustment plate 1 through which the particle beam passes. By adjusting the position of the range adjustment plate 1 and changing the total thickness of the particle beam through which the particle beam passes, the energy and range of the particle beam can be reduced or increased so that the particle beam reaches the affected area.

[0068] The plurality of driving devices 21 preferably operate independently, and one driving device 21 is preferably used to drive one range adjustment plate 1. Each range adjustment plate 1 is provided with a separate driving device 21, so that each range adjustment plate 1 can be adjusted independently, thereby avoiding mutual interference between the plurality of range adjustment plates 1, improving the speed and accuracy of the adjustment of the range adjustment plates 1, and also increasing the combination mode of the range adjustment plates 1. A plurality of range adjustment plates 1 with different total thicknesses can be combined through different numbers of range adjustment plates 1, thereby expanding the adjustment range of the range adjustment plate 1 for the particle beam, so that the radiotherapy equipment can treat tumors in a wider range.

[0069] In some embodiments, a driving device 21 is respectively disposed on both sides of each range adjustment plate 1, that is, a linear actuator 213 is respectively disposed on both sides of each range adjustment plate 1, and the two linear actuators 213 can make the movement of the range adjustment plate 1 more stable. The linear actuators 213 on both sides of each range adjustment plate 1 are not aligned along the width direction of the range adjustment plate 1, that is, the linear actuators 213 on both sides of each range adjustment plate 1 are staggered, so that the linear actuators 213 on the same side of the range adjustment plate 1 can also be staggered, so that the arrangement between adjacent range adjustment plates 1 can be made more compact, thereby making the range adjuster 100 more miniaturized. In an alternative embodiment, a driving device 21 is provided on one side of each range adjustment plate 1, and a slide rail 4 for supporting the range adjustment plate 1 is provided on the other side along the width direction of the range adjustment plate 1, and the slide rail 4 allows the range adjustment plate 1 to slide in a linear direction, so that the range adjustment plate 1 is jointly restricted by the driving device 21 and the slide rail 4, and will not move in a direction other than the movement direction of the range adjustment plate 1, and the movement direction is the axial direction of the actuating optical axis 212.

[0070] In one embodiment, the density of the boron-containing polyethylene is 1.95 to 2.15 g / cm 3 The density of boron-containing polypropylene is 1.93-2.13 g / cm 3By controlling the density of the boron-containing polyethylene or the boron-containing polypropylene, the boron content in the boron-containing polyethylene or the boron-containing polypropylene can be controlled. By controlling the boron content, the energy regulating effect of the range adjustment plate 1 on the particle beam can be improved, thereby reducing the thickness of the range adjustment plate 1, and reducing the scattering of the particle beam, keeping the increase of the beam spot after the particle beam passes through small, thereby ensuring that the particle beam reaches the affected area stably and accurately with a small beam spot. It has been verified that the boron-containing polyethylene and boron-containing polypropylene of the above density can make the range adjustment plate 1 have a better regulating effect.

[0071] Based on the width of the Bragg peak of the particle beam in water, different numbers or thicknesses of range adjustment plates 1 are combined to form combinations with different total thicknesses. The range adjustment plates 1 with different total thicknesses can enable the particle beam to reach the affected areas at different positions.

[0072] In some embodiments, the thicknesses of the multiple range adjustment plates 1 may be the same, which facilitates the production and installation of the range adjustment plates 1 , and the combination of the multiple range adjustment plates 1 is simple, which also facilitates the adjustment of the range adjustment plates 1 .

[0073] Alternatively, at least some of the range adjustment plates 1 may have different thicknesses, that is, some of the range adjustment plates 1 may have the same thickness, some of the range adjustment plates 1 may have different thicknesses, or all of the range adjustment plates 1 may have different thicknesses, which can be set according to actual needs. Range adjustment plates 1 of different thicknesses can be arranged and combined in different ways to form a variety of range adjustment plate 1 combinations with different total thicknesses, further expanding the range of particle beam adjustment by the range adjustment plates 1, so that the radiotherapy device can treat tumors within a wider range.

[0074] Each range adjustment plate 1 can also be divided into different areas, and the thickness of each area can also be different, so that more combinations of range adjustment plates 1 with different total thicknesses can be formed, further expanding the adjustment range of the range adjustment plate 1 for the particle beam, so that the radiotherapy equipment can treat tumors in a larger range.

[0075] The particle beam is a proton beam, along the proton beam direction (such as Figure 3 , Figure 4 The thickness of the last range adjustment plate 1 through which the proton beam passes is the largest. The thickness of the range adjustment plate 1 is set differently according to the Bragg peak width (80%-80%) in water under the nominal energy of the proton beam as the reference X. The equivalent water thickness of the plurality of range adjustment plates 1 is in multiple relationship along the direction of the proton beam, and the multiple relationship is 1 / 4X, 1 / 2X, 1X, 2X, 4X, 8X respectively. The range is adjusted by combining the range adjustment plates 1 with different thicknesses so as to achieve the required range under different combination conditions, and the change of the combination state can meet the range adjustment step length of the system.

[0076] As a preferred embodiment, the range adjuster 100 may further include a frame 3, a plurality of drive devices 21 are respectively arranged on opposite sides of the frame 3, and two ends of the actuating optical axis 212 are respectively arranged at opposite ends of the frame 3, that is, in the horizontal direction, the plurality of drive devices 21 are respectively arranged on opposite sides of the frame 3, and in the vertical direction, the two ends of the actuating optical axis 212 are respectively arranged at opposite ends of the frame 3, the drive motor 211 is arranged at one end of the actuating optical axis 212, and the linear actuator 213 is connected to the range adjustment plate 1 and is sleeved on the actuating optical axis 212.

[0077] Specifically, the frame 3 has a first side 33 and a second side 34 opposite to each other, and a first end 31 and a second end 32 opposite to each other. A plurality of driving devices 21 are respectively arranged on the first side 33 and the second side 34 of the frame 3. The number of driving devices 21 on the first side 33 and the second side 34 is preferably the same, so that the overall structure of the range adjuster 100 can be kept more stable. The actuating optical axis 212 has a third end 2121 and a fourth end 2122 opposite to each other. The third end 2121 of the actuating optical axis 212 is arranged on the first end 31 of the frame 3, and the fourth end 2122 of the actuating optical axis 212 is arranged on the second end 32 of the frame 3. The driving motor 211 is arranged on the third end 2121 of the actuating optical axis 212. The linear actuator 213 is arranged below the driving motor 211. The linear actuator 213 is connected to the range adjustment plate 1 and sleeved on the actuating optical axis 212. The driving motor 211 drives the actuating optical axis 212 to rotate, and the actuating optical axis 212 drives the linear actuator 213 to move up and down along the actuating optical axis 212. The linear actuator 213 then drives the range adjustment plate 1 to move up and down, moving the range adjustment plate 1 into or out of the travel path of the particle beam to adjust the total thickness of the range adjustment plate 1 through which the particle beam passes.

[0078] In some possible embodiments, the motion control mechanism 2 may further include a first position sensor 22, which is connected to the drive motor 211 and is used to detect the rotational motion of the drive motor 211 to obtain the position information of the range adjustment plate 1. The first position sensor 22 is, for example, a rotary encoder, which may be coupled to the drive motor 211, and may detect information such as the number of rotations and the direction of rotation of the drive motor 211 to obtain the position information of the linear actuator 213, and further obtain the position information of the range adjustment plate 1. The rotary encoder may feed back the position information of the range adjustment plate 1 to the motion controller 25, and the motion controller 25 controls the rotation of the drive motor 211 according to the feedback information of the rotary encoder, so that the position of the range adjustment plate 1 can be accurately controlled.

[0079] The motion control mechanism 2 may further include a second position sensor 23 . The second position sensor 23 is connected to the linear actuator 213 . The second position sensor 23 is used to detect the position of the linear actuator 213 to obtain the position information of the range adjustment plate 1 .

[0080] The second position sensor 23 is arranged corresponding to the linear actuator 213, that is, one linear actuator 213 is arranged corresponding to one second position sensor 23. The second position sensor 23 can be connected to the motion controller 25. The second position sensor 23 is used to obtain the position information of the range adjustment plate 1. The motion controller 25 controls the rotation of the drive motor 211 according to the feedback information of the second position sensor 23, so that the position of the range adjustment plate 1 can be further accurately controlled. The second position sensor 23 can be a sliding rheostat, a tensile displacement sensor, etc. In this embodiment, the second position sensor 23 is a sliding rheostat. The second position sensor 23 is arranged on the frame 3. The linear actuator 213 is provided with an elastic plunger 2134 connected to the second position sensor 23. The number of the elastic plunger 2134 can be one or more. The second position sensor 23 obtains the position information of the range adjustment plate 1 through the position of the elastic plunger 2134 on the second position sensor 23, that is, the second position sensor 23 can obtain the position information of the range adjustment plate 1 in real time.

[0081] The second position sensor 23 can be a sensor independent of the first position sensor 22, which is equivalent to the range regulator 100 having two or more independent position feedback devices, ensuring the accuracy of the position of the range adjustment plate 1, thereby ensuring the accuracy of the particle beam adjustment by the range adjustment plate 1, and also ensuring that the range regulator 100 can operate stably, avoiding damage to one of the position feedback devices resulting in inaccurate position of the range adjustment plate 1, thereby improving the safety of the operation of the range regulator 100.

[0082] The motion control mechanism 2 may further include a third position sensor 24, which is respectively arranged near the two opposite ends of the frame 3 to limit the range of motion of the linear actuator 213. That is, two third position sensors 24 are correspondingly arranged for each linear actuator 213, and the third position sensors 24 are respectively arranged at the starting position and the end position of the linear actuator 213. When the linear actuator 213 moves to the starting position or the end position, the drive motor 211 stops running to prevent the linear actuator 213 from exceeding the working range and avoiding the over-range adjustment plate 1 from being hit and damaged. The third position sensor 24 may be a Hall switch, a proximity switch, etc. In this embodiment, the third position sensor 24 is a Hall switch. A plurality of Hall switches, for example, two Hall switches, may be provided in the movement direction of each linear actuator 213. A sensing portion 2135 is provided on each linear actuator 213. When the sensing portion 2135 moves to the Hall switch, the Hall switch may feed back the position information of the range adjustment plate 1 to the motion controller 25. The motion controller 25 controls the drive motor 211 according to the feedback information of the Hall switch to stop the drive motor 211 from running, thereby preventing the linear actuator 213 from exceeding the working range and preventing the range adjustment plate 1 from being damaged by impact.

[0083] As a preferred embodiment, the first position sensor 22, the second position sensor 23 and the third position sensor 24 can operate independently without interfering with each other, and can all feedback the position information of the range adjustment plate 1, thereby ensuring the accuracy of the position measurement of the range adjustment plate 1 and increasing the reliability of the system.

[0084] The motion control mechanism 2 may further include a circuit board 26, the first position sensor 22, the second position sensor 23, the third position sensor 24 and the drive motor 211 are all connected to the circuit board 26, and the circuit board 26 is connected to the motion controller 25. The motion controller 25 controls the first position sensor 22, the second position sensor 23, the third position sensor 24 and the drive motor 211 through the circuit board 26, which can reduce the use of cables, simplify the cables of the range adjuster 100, and also improve the maintainability of the cables.

[0085] In a specific embodiment, the range adjuster 100 may further include a plurality of slide rails 4 and an adjustment bracket 5, wherein the slide rails 4 are arranged corresponding to the actuating optical axis 212 one by one, the number of the slide rails 4 is the same as the number of the actuating optical axis 212, the range adjustment plate 1 is arranged on the adjustment bracket 5, one end of the adjustment bracket 5 is connected to the linear actuator 213, and the other end of the adjustment bracket 5 is connected to the slide rail 4, and the range adjustment plate 1 is smoother and more stable during the movement, and the accuracy of the movement of the range adjustment plate 1 is improved. In this embodiment, the slide rail 4 and the actuating optical axis 212 are located on the same side of the frame 3, and the actuating optical axis 212 is closer to the outer edge of the frame 3. The adjustment bracket 5 is roughly rectangular, and the middle part of the adjustment bracket 5 has a hollow portion 51, and the range adjustment plate 1 is arranged in the hollow portion 51 of the adjustment bracket 5 and fixed by a clamping structure 52, and the clamping structure 52 facilitates the installation and removal of the range adjustment plate 1, and the number of the clamping structures 52 can be multiple, which improves the stability of the range adjustment plate 1.

[0086] In this embodiment, the driving motor 211 is provided with a first position sensor 22, which can be a rotary encoder, and the rotary encoder can detect the number of rotations and the direction of rotation of the driving motor 211, that is, the rotary encoder can obtain how much the driving motor 211 rotates, and the lead of the transmission module is fixed, and the position of the transmission module can be calculated by the rotation angle of the driving motor 211 and the lead of the transmission module. The elastic plunger 2134 on the transmission module is connected to the second position sensor 23, and the second position sensor 23 can be a sliding rheostat, and the second position sensor 23 can obtain the real-time position of the transmission module. If the position of the transmission module calculated by the first position sensor 22 is the same as the position of the transmission module detected by the second position sensor 23, it means that the load on the transmission module does not exceed the threshold value, and if the position of the transmission module calculated by the first position sensor 22 is different from the position of the transmission module detected by the second position sensor 23, it means that the load on the transmission module exceeds the threshold value, and the transmission roller slides or slips on the actuating optical axis 212.

[0087] The range adjuster 100 may further include a limiter 6, which is respectively disposed at two opposite ends of the frame 3, that is, the limiter 6 is respectively disposed at the first end 31 and the second end 32 of the frame 3, and the limiter 6 is used to limit the range of movement of the range adjustment plate 1. The limiter 6 can prevent the range adjustment plate 1 from directly hitting the frame 3, and has a protective effect on the range adjustment plate 1. The material of the limiter 6 is preferably an elastic material, and the elastic material has a buffering effect, further reducing the impact force on the range adjustment plate 1.

[0088] A buffer may also be provided on one side of the adjustment bracket 5 facing the limiting device 6 . The material of the buffer is preferably an elastic material. The elastic material has a buffering effect and can also reduce the impact force on the range adjustment plate 1 .

[0089] The vertical movement range of the range adjustment plate 1 is preferably greater than twice the height of the range adjustment plate 1 , so that it is more convenient to adjust the position of the range adjustment plate 1 .

[0090] Reference Figure 6 , respectively made of polycarbonate, graphite, and boron-containing polyethylene / propylene, under the same test conditions, a simulation test of reducing the energy of a particle beam with an energy of 230 MeV to zero is performed, and the total thickness of the range adjustment plate 1 required is compared. It can be seen from the figure that the thickness of the range adjustment plate 1 made of boron-containing polyethylene / propylene is the smallest, indicating that the range adjustment plate 1 made of boron-containing polyethylene / propylene has a better effect on reducing the energy of the particle beam, that is, under the same conditions, the thickness of the range adjustment plate 1 made of boron-containing polyethylene / propylene can be thinner, thereby reducing the weight of the range adjustment plate 1.

[0091] Reference Figure 7 , the range adjustment plates 1 made of polycarbonate, graphite, and boron-containing polyethylene / propylene, respectively, when the particle beam with energy of 230MeV is adjusted to the particle beam with energy of 70MeV under the same test conditions, the beam spot size of the particle beam is compared. As can be seen from the figure, the beam spot of the particle beam is the smallest when it passes through the range adjustment plate 1 made of boron-containing polyethylene / propylene, indicating that the range adjustment plate 1 made of boron-containing polyethylene / propylene can reduce the scattering of the particle beam and keep the beam spot of the particle beam stable, thereby ensuring that the particle beam reaches the affected area stably and accurately with a very small beam spot.

[0092] The present invention also provides a radiotherapy device, including a treatment frame (not shown), a particle accelerator (not shown), a scanning magnet (not shown), an ionization chamber (not shown) and a range adjuster 100 as described above. The radiotherapy device can be configured to have no beam transmission line, and the particle accelerator is mounted on the treatment frame and can rotate with the treatment frame. The treatment frame can also be called a rotating frame. In some possible ways, the radiotherapy device is a proton therapy device, the particle accelerator can be a proton accelerator, the particle beam can be a proton beam, and the flowing particle beam is referred to as a particle beam. The particle beam transmission system is used to transmit the particle beam from the accelerator to the patient's body. The particle beam transmission system controls the magnetic field to accurately transmit the particle beam to the treatment position to ensure the accurate positioning and transmission of the particle beam. The particle beam transmission system may include components passed during the particle beam transmission process, such as a scanning magnet, an ionization chamber, an adaptive grating (Adaptive Aperture), etc. The scanning magnet allows the particle beam to move in the X direction and / or the Y direction by appropriately changing the magnetic field, and the X direction and the Y direction are perpendicular to each other. The ionization chamber can be used to measure the dose size and / or position of the beam. The adaptive grating can also form an adaptive aperture, which can be adaptively adjusted according to the shape and size of the target area, so that the shape and size of the particle beam can match the morphology of the tumor. The advantage of this adaptive irradiation is that it can better adapt to irregularly shaped tumors, improving the personalization and targeting of the irradiation plan. The combination of components such as the scanning magnet, the ionization chamber, the range adjuster 100 (also called the range adjuster or Rangeshifter) and the adaptive grating can provide patients with accurate and flexible radiotherapy.

[0093] The accelerator is mounted on the treatment frame and can rotate with it. This integrated design can reduce the complexity of the equipment because it does not require a beam transmission line, thereby simplifying the structure of the equipment; it also improves the stability of the beam, because the beam transmission line inevitably introduces factors of beam instability. Radiotherapy equipment does not require a beam transmission line, thereby reducing the maintenance cost and failure rate of the equipment and improving the stability and reliability of the equipment; reducing the introduction of unstable factors, the movement of the beam is more stable, which helps to maintain the stability of the particle beam and ensure accurate irradiation. Among them, the aforementioned beam transmission line includes components such as a dipole magnet and / or a quadrupole magnet.

[0094] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, substitute and modify the above embodiments within the scope of the invention without departing from the principles and purpose of the present invention. All such changes should fall within the scope of protection of the claims of the present invention.

Claims

1. A linear actuator, characterized in that: include: At least one transmission module for driving the driven object to move in a linear direction, the transmission module is sleeved on an actuating optical axis for realizing rotational motion, the transmission module includes at least two transmission rollers, a support block and a clamping block, the transmission roller includes a transmission screw and bearings respectively arranged at both ends of the transmission screw for slidingly cooperating with the support block and the clamping block respectively, each of the transmission screws is arranged non-parallel to the axis of the actuating optical axis, the transmission screw and the actuating optical axis are connected without threads, at least two of the transmission screws are clamped on the actuating optical axis, so that the transmission module can be moved along the axis of the actuating optical axis. When there is a load in the linear direction and the load does not exceed a threshold value, it is used to drive the driven object to move linearly along the axial direction of the actuating optical axis, and the two transmission screws are not parallel to each other but are located on both sides of the axis of the actuating optical axis; the transmission module is configured so that when the load it receives exceeds a threshold value, the transmission roller is used to slide on the actuating optical axis; the support block and the clamping block are both provided with a through hole for the actuating optical axis to pass through in a linear direction, the support block has a accommodating space formed by a bottom wall and side walls, the transmission roller is arranged in the accommodating space, and the clamping block is provided with a groove for accommodating at least part of the bearing.

2. The linear actuator according to claim 1, characterized in that: The transmission module comprises a first transmission module, the first transmission module comprises at least two first transmission rollers, a first support block and a first clamping block, the first support block has a first bottom wall and a first side wall, the first bottom wall and the first side wall are surrounded to form a first accommodation space, the first transmission roller and the first clamping block are arranged in the first accommodation space, the first clamping block is fixedly connected to the first side wall by a first fastener, and the load of the first transmission module is controlled by adjusting the distance from the first clamping block to the first bottom wall; The first transmission roller includes a first transmission screw and a first bearing and a second bearing respectively arranged at both ends of the first transmission screw. The first transmission screw is clamped on the actuating optical axis. The first bottom wall is provided with a first groove for accommodating at least part of the first bearing. The first clamping block is provided with a second groove for accommodating at least part of the second bearing.

3. The linear actuator according to claim 2, characterized in that: The transmission module also includes a second transmission module, the second transmission module includes at least two second transmission rollers, a second support block and a second clamping block, the second support block has a second bottom wall and a second side wall, the second bottom wall and the second side wall are surrounded to form a second accommodating space, the second transmission roller and the second clamping block are arranged in the second accommodating space, the second clamping block is fixedly connected to the second side wall by a second fastener, and the size of the load of the second transmission module is controlled by adjusting the distance from the second clamping block to the second bottom wall; The second transmission roller includes a second transmission screw and a third bearing and a fourth bearing respectively arranged at both ends of the second transmission screw, the second transmission screw is clamped on the actuating optical axis, the second bottom wall is provided with a third groove for accommodating at least part of the third bearing, and the second clamping block is provided with a fourth groove for accommodating at least part of the fourth bearing.

4. The linear actuator according to claim 3, characterized in that: The transmission module further includes a connecting block, and the first bottom wall and the second bottom wall are respectively disposed at two ends of the connecting block and are fixedly connected to the two ends of the connecting block respectively through a third fastener.

5. A range adjuster, characterized in that: include: A range adjustment plate, wherein the range adjustment plate is used for allowing the particle beam to pass through; A motion control mechanism, the motion control mechanism includes a drive device and a motion controller, the motion controller is used to control the drive device, the drive device includes a drive motor and a linear actuator as described in any one of claims 1 to 4, the drive device is used to drive the range adjustment plate to move the range adjustment plate into or out of the travel path of the particle beam to adjust the thickness of the range adjustment plate through which the particle beam passes.

6. The range adjuster according to claim 5, characterized in that: A linear actuator is respectively provided on both sides of the range adjustment plate, and the linear actuators on both sides of the range adjustment plate are not aligned along the width direction of the range adjustment plate.

7. The range adjuster according to claim 5, characterized in that: It also includes a frame, the driving device is arranged on two opposite sides of the frame, the two ends of the actuating optical axis are respectively arranged at two opposite ends of the frame, the driving motor is arranged at one end of the actuating optical axis, and the linear actuator is connected to the range adjustment plate and sleeved on the actuating optical axis.

8. The range adjuster according to claim 7, characterized in that: The motion control mechanism further includes a first position sensor, which is connected to the drive motor and is used to detect the rotational motion of the drive motor to obtain position information of the range adjustment plate; and / or, The motion control mechanism further includes a second position sensor, the second position sensor is connected to the linear actuator, and the second position sensor is used to detect the position of the linear actuator to obtain the position information of the range adjustment plate; and / or, The motion control mechanism further includes a third position sensor, which is disposed near two opposite ends of the frame to limit the motion range of the linear actuator.

9. The range adjuster according to claim 8, characterized in that: The second position sensor is arranged on the frame, the linear actuator is provided with an elastic plunger connected to the second position sensor, and the second position sensor obtains the position information of the range adjustment plate through the position of the elastic plunger on the second position sensor; and / or, The motion control mechanism further includes a circuit board, the first position sensor, the second position sensor, the third position sensor and the drive motor are all connected to the circuit board, and the circuit board is connected to the motion controller.

10. The range adjuster according to claim 7, characterized in that: It also includes a plurality of slide rails and adjustment brackets, wherein the slide rails are arranged corresponding to the actuating optical axes one by one, the range adjustment plate is arranged on the adjustment bracket, one end of the adjustment bracket is connected to the linear actuator, and the other end of the adjustment bracket is connected to the slide rail.

11. The range adjuster according to claim 10, characterized in that: It also includes a limiting device, which is respectively arranged at two opposite ends of the frame, and is used to limit the range of movement of the range adjustment plate; or, There are a plurality of range adjustment plates, and gaps are left between adjacent range adjustment plates so that the movements of each range adjustment plate will not interfere with or affect each other.

12. The range adjuster according to claim 11, characterized in that: Buffering parts are arranged at both ends of the adjustment bracket facing the limiting device.

13. A radiotherapy device, characterized in that: The invention comprises a treatment frame, a particle accelerator, a scanning magnet, an ionization chamber and a range adjuster as described in any one of claims 5 to 12.

Images