CN117771564A - Source closing device and radiotherapy equipment using same - Google Patents

Abstract

The invention discloses a source closing device, wherein a source closing mechanism comprises a source closing rod and a driving assembly, the source closing rod is connected with the driving assembly, and the source closing mechanism is used for opening and closing a source of a treatment head; under the condition that an electric control system normally closes the source, automatic closing of the source is realized; under the condition that the electric control system cannot normally close the source, the manual source closing is realized. After manual source closing, the source closing outer sleeve cannot drive the source closing inner sleeve to rotate, at the moment, the source switch cannot rotate, and the equipment can be kept at a source closing position. The manual source closing can not influence the electric source opening, and the manual source closing is realized by pulling the pull rod, so that the operator is prevented from being exposed in rays, and the radiation to the operator is reduced.

Description

Source closing device and radiotherapy equipment using same

Technical Field

The invention relates to the technical field of head radiotherapy equipment, in particular to a source closing device and radiotherapy equipment applied by the source closing device.

Background

The radiation source of the radiotherapy equipment generally comprises a gamma ray source and an accelerator X-ray source, wherein the gamma ray source commonly uses a cobalt 60 source for example, which continuously generates radiation by using artificial radioactive isotopes to carry out radiotherapy, the radiation emitted by the radiation source passes through human epidermis from different angles to irradiate tumor focus, and a source closing device with a manual source closing function is also disclosed in the prior art so as to ensure that the radiation source can be closed in time when the radiation treatment equipment fails or cannot normally close during the working process, but how to reduce the radiation to an operator during the manual source closing process, especially for the radiotherapy equipment which needs to open a self-shielding door to carry out manual source closing.

Disclosure of Invention

In order to solve the technical problems, the invention provides a source closing device, wherein a source closing mechanism comprises a source closing rod and a driving assembly, the source closing rod is connected with the driving assembly, and the source closing mechanism is used for opening and closing a source of a treatment head;

under the condition that an electric control system normally closes the source, automatic light closing is realized; under the condition that the electric control system cannot normally switch off the source, manual source switching off is realized.

Preferably: the source closing rod is connected with the driving assembly, the driving assembly is connected with the first source switch shaft sprocket, the driving assembly is connected with the first motor reducer, and the first motor reducer is fixed on the treatment head assembly.

Preferably: one side of the first motor speed reducer is provided with a second motor speed reducer, and the second motor speed reducer is connected with a transmission shaft chain wheel of the terminal collimator through a transmission part.

Preferably: the terminal collimator transmission shaft sprocket fixed connection terminal collimator transmission shaft, terminal collimator transmission shaft bottom is provided with terminal collimator transmission shaft drive gear, and terminal collimator corresponds terminal collimator transmission shaft drive gear and has seted up the jack, is provided with in the jack with terminal collimator transmission shaft drive gear complex protruding key, terminal collimator transmission shaft rotation can drive terminal collimator rotation.

Preferably: the terminal collimator transmission shaft outside is provided with the source switch transmission shaft, and the source switch transmission shaft is cavity form, source switch transmission shaft upper end fixed connection source switch transmission shaft sprocket, source switch transmission shaft bottom fixed connection source switch transmission shaft drive gear, and the jack has been seted up to the source switch corresponding to source switch transmission shaft drive gear, is provided with in the jack with source switch transmission shaft drive gear complex protruding key, source switch transmission shaft rotation energy drive source switch rotation.

Preferably: the source switch transmission shaft chain wheel is connected with a second chain, and the other end of the second chain is connected with the first source switch shaft chain wheel.

Preferably: the driving assembly comprises a source closing outer sleeve and a source closing inner sleeve, and the source closing outer sleeve and the source closing inner sleeve are matched to rotate to realize manual source closing.

Preferably: the power source closing sleeve is characterized in that an inserting block is arranged at the upper end of the power source closing sleeve, a check ring groove is formed in the outer wall of the lower portion of the power source closing sleeve, a first boss and a second boss are arranged in a cavity at the bottom of the power source closing sleeve, and a sliding groove is formed between the first boss and the second boss.

Preferably: the upper part of the source closing inner sleeve is provided with an inserting part, the outer wall of the inserting part is provided with a shifting block, the inner wall of the bottom of the source closing inner sleeve is provided with an annular groove, the inner diameter of the annular groove is larger than the inner diameter of the Yu Guanyuan inner sleeve, and the inner wall of the annular groove is provided with a protruding part.

A radiotherapy apparatus uses a source-closing device for switching on and off the source.

The invention has the technical effects and advantages that:

1. according to the invention, through the arranged source closing mechanism, in the conventional treatment process, the switching source operation is to drive the first motor speed reducer to open and close the source, and in the electric source opening or closing process, the manual source closing in the abnormal source closing state is not influenced.

2. In the invention, under the condition that the source cannot be normally closed, an operator pulls the pull ring, pulls the source closing rod through the action of the steel wire, and the manual source closing rod rotates clockwise, so that the hole position of the source switch and the hole position of the collimator are completely misplaced, the ray source is closed to emit beams, manual source closing is realized, after the manual source closing, the source closing outer sleeve does not drive the source closing inner sleeve to rotate, at the moment, the source switch does not rotate, the equipment is still in the source closing position, and the manual source closing does not influence the electric source opening.

3. According to the invention, when the radiotherapy equipment is in the state that the front shielding door and the rear shielding door are closed, the inclined positions of the treatment head assembly and the treatment head are judged through the identification piece, so that the ray beam emitting position is judged, an operator stands on the opposite face of the ray beam emitting position, and after the rear shielding door on the opposite face is opened, the pull rod is pulled to realize manual source closing, so that the operator is prevented from being exposed in rays, and the radiation to the operator is reduced.

Drawings

Fig. 1 is a schematic structural diagram of a therapeutic head in a source-closing device according to an embodiment of the present application;

FIG. 2 is a top view of a treatment head in a source-closing device provided in an embodiment of the present application;

FIG. 3 is a cross-sectional view of a treatment head in a source-closing device provided in an embodiment of the present application;

FIG. 4 is an enlarged schematic view of the structure at A in FIG. 3 in a source closing device according to an embodiment of the present application;

FIG. 5 is a schematic view of a source-related device with a treatment head removed from its housing;

fig. 6 is a schematic structural diagram of a source closing mechanism in a source closing device according to an embodiment of the present application;

FIG. 7 is a cross-sectional view of a source closing mechanism in a source closing device provided in an embodiment of the present application;

FIG. 8 is an enlarged schematic view of the structure at B in FIG. 7 in a source-closing device according to an embodiment of the present application;

FIG. 9 is an exploded view of a source closing mechanism in a source closing device according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a source closing rod in the source closing device according to the embodiment of the present application;

FIG. 11 is a schematic structural view of a source closing jacket in a source closing device according to an embodiment of the present disclosure;

FIG. 12 is a schematic view of a source-closing inner sleeve in a source-closing device according to an embodiment of the present disclosure;

fig. 13 is a schematic structural diagram of a first source switching shaft sprocket in a source closing device according to an embodiment of the present application.

Fig. 14 is a schematic structural diagram of a radiotherapy apparatus applied to a source-closing device according to an embodiment of the present application.

In the figure: 1. a frame base; 101. a slip ring assembly; 102. a marking piece; 2. a treatment head assembly; 3. a treatment head; 301. a shield; 302. a source box; 303. a source switch; 304. a terminal collimator; 4. a source closing mechanism; 5. a support frame; 501. a fixing member; 502. a godet wheel; 503. a guidewire tube; 6. a first pull ring; 7. a second pull ring; 8. an end cap; 9. closing a source rod; 901. a clamping groove; 902. a wire hole; 903. a through hole; 10. a first motor speed reducer; 11. a second motor speed reducer; 12. a second source switching shaft sprocket; 13. a first chain; 14. a housing; 15. a terminal collimator drive shaft sprocket; 16. a source switch drive shaft sprocket; 17. a terminal collimator drive shaft; 171. a terminal collimator drive shaft drive gear; 18. a source switch drive shaft; 181. a source switch drive shaft drive gear; 19. a bearing end cap; 20. a first source switching shaft sprocket; 2001. an annular protrusion; 2002. sprocket grooves; 2003. a fixing hole; 21. a second chain; 22. a drive assembly; 221. a bearing platen; 222. closing a source coat; 2221. inserting blocks; 2222. a first boss; 2223. a second boss; 2224. a chute; 2225. a retainer ring groove; 223. a source closing inner sleeve; 2231. an insertion section; 2232. a shifting block; 2233. an annular groove; 2234. a protruding portion; 224. a bearing; 225. an output shaft of the motor speed reducer; 226. an expansion sleeve; 227. a fixing frame; 228. a fastening screw; 229. and (5) a retainer ring.

Detailed Description

The invention will be described in further detail with reference to the drawings and the detailed description. The embodiments of the invention have been presented for purposes of illustration and description, and are not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

In this embodiment, referring to fig. 1-6, the source closing mechanism 4 comprises a source closing rod 9 and a driving component 22, and is used for opening and closing the source of the treatment head 3, the treatment head 3 comprises a shell 14, the shell 14 is fixed on the treatment head assembly 2, the shell 14 is connected with a shielding cover 301, a source box 302, a source switch 303 and a terminal collimator 304 are arranged in the shell 14, an end cover 8 is arranged at the top end of the shielding cover 301, the source box 302 is arranged in the shielding cover 301 through the end cover 8, a supporting frame 5 is fixed at the top end of one side of the treatment head 3, the supporting frame 5 comprises a fixing piece 501, the fixing piece 501 is fixed on the treatment head 3, two godet wheels 502 are arranged at the upper end of the fixing piece 501, two godet wheels 502 are used for supporting wires, a godet 503 is fixed on the fixing piece 501, two godet pipes 503 are arranged, a first pull ring 6 is arranged at the outer side of one godet 503, a second pull ring 7 is arranged at the outer side of the other godet 503, the first pull ring 6 and the second pull ring 7 are fixedly connected with guide wires, the two guide wires pass through a guide wire pipe 503 and are connected with a source closing rod 9 through a guide wire wheel 502, the source closing rod 9 is connected with a driving component 22, the driving component 22 is connected with a first source switching shaft chain wheel 20, the driving component 22 is connected with a first motor reducer 10, the first motor reducer 10 is fixed on the treatment head assembly 2, one side of the first motor reducer 10 is provided with a second motor reducer 11, the second motor reducer 11 is fixed on the treatment head assembly 2, the second motor reducer 11 is connected with a second source switching shaft chain wheel 12, the second source switching shaft chain wheel 12 is connected with a first chain 13, the other end of the first chain 13 is connected with a terminal collimator transmission shaft chain wheel 15, the terminal collimator transmission shaft chain wheel 15 is fixedly connected with a terminal collimator transmission shaft 17, the bottom end of the terminal collimator transmission shaft 17 is provided with a terminal collimator transmission shaft driving gear 171, and terminal collimator 304 has offered the jack corresponding to terminal collimator transmission shaft drive gear 171, be provided with in the jack with terminal collimator transmission shaft drive gear 171 complex protruding key, terminal collimator transmission shaft 17 rotation can drive terminal collimator 304 rotation, terminal collimator transmission shaft 17 upper end passes through bearing rotation connection shield 301, be located terminal collimator transmission shaft 17 top and install bearing end cover 19, be used for the outer lane of fixed bearing, terminal collimator transmission shaft 17 outside is provided with source switch transmission shaft 18, source switch transmission shaft 18 is hollow form, source switch transmission shaft 18 upper end fixed connection source switch transmission shaft sprocket 16, source switch transmission shaft 18 bottom fixed connection source switch transmission shaft drive gear 181, and source switch 303 has offered the jack corresponding to source switch transmission shaft drive gear 181, be provided with in the jack with source switch transmission shaft drive gear 181 complex protruding key, source switch transmission shaft 18 rotation can drive source switch 303 rotation, source switch transmission shaft 18 upper end passes through bearing rotation connection shield 301, second motor reducer 11 rotates, drive second source switch shaft sprocket 12 rotates, and drive source switch transmission shaft 16 rotates through first chain 13, and then drive source switch transmission shaft 18, source switch transmission shaft drive source switch transmission shaft 181 and source switch drive gear 181.

Further, the source switch transmission shaft sprocket 16 is connected with the second chain 21, the other end of the second chain 21 is connected with the first source switch shaft sprocket 20, the first motor reducer 10 rotates to drive the first source switch shaft sprocket 20 to rotate, and the second chain 21 can drive the terminal collimator transmission shaft sprocket 15 to rotate so as to drive the terminal collimator transmission shaft 17, the terminal collimator transmission shaft driving gear 171 and the terminal collimator 304 to rotate.

The source switch 303 (also called a primary collimator, generally having a set of holes thereon), and a terminal collimator (a secondary collimator having a plurality of sets of collimation holes thereon, each set having a different size and a different size of generated radiation field), wherein the source switch 303 can be rotated to switch off the source during use, and the collimator also has a motor to drive the collimator to rotate, so that the different collimation hole sets are aligned with the holes of the source switch, so that the radiation beam can be emitted and focused to form an isocenter, and radiation treatment is performed on focal tissues.

In this embodiment, referring to fig. 7-9, the driving assembly 22 includes a bearing platen 221, the bearing platen 221 is sleeved at the lower end of the source closing rod 9, a related source jacket 222 is disposed at the inner side of the source closing rod 9, a threaded hole is formed in the middle of the source closing jacket 222, a fastening screw 228 is screwed into the threaded hole through the through hole in the middle of the source closing rod 9, the bearing platen 221 and the source closing jacket 222 are fixed with the source closing rod 9, a bearing 224 is sleeved at the outer side of the source closing jacket 222, a groove is formed at the position below the bearing 224 on the outer wall of the source closing jacket 222, the groove is used for sleeving a retainer ring 229, the retainer ring 229 is used for supporting the inner ring of the bearing 224, the outer ring of the bearing 224 is tightly attached to the lower end face of the source closing jacket 222, the source closing jacket 222 is internally inserted with the source closing jacket 223, the source closing inner sleeve 223 is positioned at the upper end of the first source switching shaft chain wheel 20, an expansion sleeve 226 is arranged in the first source switching shaft chain wheel 20, the upper end of the expansion sleeve 226 extends into the source closing inner sleeve 223, the expansion sleeve 226 is connected with a motor speed reducer output shaft 225, the motor speed reducer output shaft 225 is connected with the first motor speed reducer 10, the first motor speed reducer 10 is fixedly connected with a fixing frame 227, the motor speed reducer output shaft 225 extends into the source closing inner sleeve 223, and after a bolt passes through a through hole in the middle of the source closing inner sleeve 223 and is connected with a threaded hole at the tail end of the motor speed reducer output shaft 225, the source closing inner sleeve 223, the expansion sleeve 226 and the first source switching shaft chain wheel 20 are installed on the motor speed reducer output shaft 225.

Further, referring to fig. 10, a through hole 903 is formed at one end of Guan Yuangan 9 corresponding to a fastening screw, a clamping groove 901 is formed at the bottom end of Guan Yuangan, the clamping groove 901 is communicated with the through hole 903, a wire hole 902 is formed at one end of the source closing rod 9 far away from the through hole 903, two wire holes 902 are formed, two wire holes 902 are respectively used for connecting two wires, one wire is connected with the first pull ring 6, the other wire is connected with the second pull ring 7, the first pull ring 6 is pulled, the source closing rod 9 can be pulled to rotate clockwise through the wires, after manual source closing is completed, the source closing rod 9 can be driven to reset through the first motor speed reducer 10, the second pull ring 7 is pulled to rotate clockwise through the wires, after manual source closing is completed, the source closing rod 9 can be driven to reset through the first motor speed reducer 10, and through the design of the structure, an operator can manually close the source from the first pull ring 6 or the second pull ring 7.

Referring to fig. 11, an insert block 2221 is disposed at the upper end of the source closing casing 222, the insert block 2221 is adapted to the card slot 901, the insert block 2221 is inserted into the card slot 901, a retainer ring slot 2225 is formed in the outer wall of the lower portion of the source closing casing 222, the retainer ring slot 2225 is used for installing the retainer ring 229, the retainer ring 229 is prevented from falling off from the source closing casing 222, a first boss 2222 and a second boss 2223 are disposed in a cavity at the bottom of the source closing casing 222, a sliding groove 2224 is disposed between the first boss 2222 and the second boss 2223, the first boss 2222 and the second boss 2223 are located on the same vertical plane, preferably, the insert block 2221 is a hexagonal nut and is matched with the source closing rod 9, and fixed with the source closing rod 9 through a fastening screw 228.

Referring to fig. 12, an insertion portion 2231 is disposed at the upper portion of the source closing inner sleeve 223, the outer diameter of the insertion portion 2231 is smaller than the outer diameter of the inner sleeve 223 of Yu Guanyuan, the insertion portion 2231 is used for being inserted into a cavity at the bottom of the source closing outer sleeve 222, a shifting block 2232 is disposed at the outer wall of the insertion portion 2231, the shifting block 2232 is located in a sliding groove 2224, an annular groove 2233 is formed in the inner wall at the bottom of the source closing inner sleeve 223, the inner diameter of the annular groove 2233 is larger than the inner diameter of the inner sleeve 223 of Yu Guanyuan, protruding portions 2234 are disposed at the inner wall of the annular groove 2233, and two protruding portions 2234 are symmetrically disposed.

Referring to fig. 13, an annular protrusion 2001 is provided at the upper end of the first source switching shaft sprocket 20, two sprocket grooves 2002 are provided on the annular protrusion 2001 corresponding to the protrusion 2234, at least one fixing hole 2003 is provided on the outer wall of the first source switching shaft sprocket 20, and the fixing hole 2003 is used for inserting a fastening screw to be fixedly connected with the motor reducer output shaft 225.

Specifically, when the poking block 2232 is in the initial state, the second boss 2223 is attached, and when the source is required to be manually turned off, the steel wire pulls the source turning rod 9 to rotate clockwise, so as to drive the source turning outer sleeve 222 to rotate clockwise, the second boss 2223 pushes the poking block 2232 to rotate clockwise, so that the source turning inner sleeve 223 and the first source switch shaft sprocket 20 rotate clockwise, the first chain 13 drives the source switch transmission shaft sprocket 16, the source switch transmission shaft 18 and the source switch 303 to rotate, and the alignment holes of the source switch 303 and the alignment holes of the source box 302 and the terminal collimator 304 are staggered, so that the manual source turning is realized.

Manual source closing process: the operator pulls the first pull ring 6 or the second pull ring 7, manually pulls the source closing rod 9 through the action of a steel wire, manually rotates Guan Yuangan clockwise, simultaneously drives the source closing outer sleeve 222 to rotate together, the second boss 2223 inside the source closing outer sleeve 222 is in contact with the shifting block 2232 of the source closing inner sleeve 223, drives the source closing inner sleeve 223 to rotate clockwise, drives the first source switch shaft sprocket 20 and the motor reducer output shaft 225 fixed with the source closing inner sleeve 223 to rotate clockwise from the source closing inner sleeve 223, drives the source switch transmission shaft sprocket 16 to rotate clockwise through the first chain 13, and enables the source switch 303 to rotate clockwise by a certain angle, so that the hole position of the source switch 303 is completely misplaced with the hole position of the collimator, and the ray source is closed.

It should be noted that, the manual source closing is used under the condition that the source cannot be normally closed, after the equipment is maintained after the manual source closing, the source closing rod 9 must be rotated to the initial position every time, during this process, the source closing outer sleeve 222 rotates anticlockwise, the shifting block 2232 of the source closing inner sleeve 223 moves relatively along the sliding groove 2224, the shifting block 2232 is attached to the second boss 2223 from the position attached to the first boss 2222, the shifting block 2232 rotates anticlockwise, the source closing outer sleeve 222 does not drive the source closing inner sleeve 223 to rotate, at this time, the source switch does not rotate, the equipment is still at the source closing position, and the manual source closing does not affect the electric source opening.

The electric switching source process comprises the following steps:

in the conventional treatment process, the switch source operation is to drive the first motor reducer 10 to open and close the source, in the process of electrically opening or closing the source, the first motor reducer 10 drives the first source switch shaft sprocket 20 to rotate, and drives the source switch transmission shaft sprocket 16 and the source switch transmission shaft 18 to rotate through the second chain 21, so that the source switch 303 rotates clockwise or anticlockwise by a certain angle, the source switch 303 is closed or opened (the hole site of the source switch 303 and the hole site of the collimator are completely misplaced or aligned and communicated), in the process, the motor reducer output shaft 225 rotates and simultaneously drives the source closing inner sleeve 223 to rotate, but at the moment, the shifting block 2232 of the source closing inner sleeve 223 slides along the inside of the sliding groove 2224, the first motor reducer 10 stops rotating to the second boss 2223, the source closing outer sleeve 222 does not drive the source closing inner sleeve 223 to rotate, at the moment, the source switch is not rotated, the equipment is still at the source closing position, and the manual source closing cannot influence the electrically opening source.

After manual power off, if the equipment is not maintained normally, the power off rod 9 is forgotten to swing to the initial position, when the first motor reducer 10 is powered on, the motor reducer output shaft 225 drives the power off inner sleeve 223 to rotate, the shifting block 2232 of the power off inner sleeve 223 interferes with the second boss 2223 of the power off outer sleeve 222 and acts on the second boss 2223 to enable the power off outer sleeve 222 to drive Guan Yuangan to return to the initial position, but after that, when power off or power on is performed, the manual power off rod 9 stays at the initial position, the shifting block 2232 of the power off inner sleeve 223 rotates to be attached to the side face of the second boss 2223 after each power on, and when the power off is performed manually next time, the rotation of the power off outer sleeve 222 acts on the shifting block 2232 of the power off inner sleeve 223, so that the power off inner sleeve 223 rotates to drive the power off switch 303 to rotate to the power off position.

Further, if the marking piece 102 is inclined leftwards, the treatment head assembly 2 and the treatment head 3 are inclined leftwards, the radiation beam emission direction is rightwards, an operator stands on the left side to pull the second pull ring 7, the source closing rod 9 is driven to rotate clockwise through the steel wire, manual source closing is achieved, if the marking piece 102 is inclined rightwards, the treatment head assembly 2 and the treatment head 3 are inclined rightwards, the radiation beam emission direction is leftwards, the operator stands on the right side to pull the first pull ring 6, and the source closing rod 9 is driven to rotate clockwise through the steel wire, so that manual source closing is achieved.

When the radiotherapy equipment is in a front shielding door and a rear shielding door in a closed state, the inclined positions of the treatment head assembly 2 and the treatment head 3 are judged through the identification piece 102, the ray beam emitting position is further judged, an operator stands on the opposite face of the ray beam emitting position, and after the rear shielding door on the opposite face is opened, the pull rod is pulled to realize manual source closing, so that the operator is prevented from being exposed in rays, and the radiation to the operator is reduced.

Referring to fig. 14, in another embodiment, there is further provided a radiotherapy apparatus, which includes a frame base 1, a therapeutic head assembly 2 is rotatably connected to the frame base 1, a slip ring assembly 101 is installed at a connection between the frame base 1 and the therapeutic head assembly 2, an identifier 102 is provided on the slip ring assembly 101, the identifier 102 rotates along with rotation of the therapeutic head assembly 2, a therapeutic head 3 is installed on the therapeutic head assembly 2, a source closing mechanism 4 is installed on the therapeutic head 3, the source closing mechanism 4 is matched with the identifier 102, and an operator stands on a side inclined by the identifier 102 to perform manual source closing, so that radiation to the operator can be reduced.

It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art and which are included in the embodiments of the present invention without the inventive step, are intended to be within the scope of the present invention. Structures, devices and methods of operation not specifically described and illustrated herein, unless otherwise indicated and limited, are implemented according to conventional means in the art.

Claims (10)

1. The source closing device comprises a source closing mechanism, and is characterized by comprising a source closing rod and a driving assembly, wherein the source closing rod is connected with the driving assembly, and the source closing mechanism is used for opening and closing a source of a treatment head;

under the condition that an electric control system normally closes the source, automatic closing of the source is realized; under the condition that the electric control system cannot normally switch off the source, manual source switching off is realized.

2. The source closing device of claim 1, wherein the source closing rod is connected to a driving assembly, the driving assembly is connected to a first source switching shaft sprocket, and the driving assembly is connected to a first motor reducer, the first motor reducer being fixed to the treatment head assembly.

3. The source closing device according to claim 1, wherein a second motor reducer is arranged on one side of the first motor reducer, and the second motor reducer is connected with a terminal collimator transmission shaft sprocket through a transmission component.

4. A source closing device according to claim 3, wherein the terminal collimator transmission shaft sprocket is fixedly connected with a terminal collimator transmission shaft, a terminal collimator transmission shaft driving gear is arranged at the bottom end of the terminal collimator transmission shaft, a jack is arranged in the jack corresponding to the terminal collimator transmission shaft driving gear, a convex key matched with the terminal collimator transmission shaft driving gear is arranged in the jack, and the terminal collimator transmission shaft can be driven to rotate by rotating.

5. The source closing device according to claim 4, wherein an active switch transmission shaft is arranged on the outer side of the terminal collimator transmission shaft, the active switch transmission shaft is hollow, the upper end of the active switch transmission shaft is fixedly connected with a source switch transmission shaft sprocket, the bottom end of the active switch transmission shaft is fixedly connected with a source switch transmission shaft driving gear, a jack is formed in the active switch corresponding to the source switch transmission shaft driving gear, a convex key matched with the source switch transmission shaft driving gear is arranged in the jack, and the source switch transmission shaft can rotate to drive the source switch.

6. The source closing device according to claim 5, wherein the source switch drive shaft sprocket is connected to a second chain, and the other end of the second chain is connected to the first source switch shaft sprocket.

7. The source closing device according to claim 6, wherein the driving assembly comprises a source closing outer sleeve and a source closing inner sleeve, and the source closing outer sleeve and the source closing inner sleeve are matched to rotate to realize manual source closing.

8. The source closing device according to claim 1, wherein an insert block is arranged at the upper end of the source closing sleeve, a retainer ring groove is formed in the outer wall of the lower portion of the source closing sleeve, a first boss and a second boss are arranged in a cavity at the bottom of the source closing sleeve, and a sliding groove is formed between the first boss and the second boss.

9. The source closing device according to claim 8, wherein an insertion part is arranged at the upper part of the source closing inner sleeve, a poking block is arranged on the outer wall of the insertion part, an annular groove is formed in the inner wall of the bottom of the source closing inner sleeve, the inner diameter of the annular groove is larger than the inner diameter of the Yu Guanyuan inner sleeve, and a protruding part is arranged on the inner wall of the annular groove.

10. A radiotherapy apparatus characterised in that a source-switching device according to any one of claims 1 to 9 is used for switching sources on and off.