Magnetic rotor protection structure for printing

Abstract

The application provides a printing magnetic rotor protection structure and relates to the technical field of motor parts. The printing magnetic rotor protection structure comprises a protection bottom plate and a rotor body. A support shell is arranged above the protection bottom plate. An electromagnetic jacket is arranged in the support shell. A plurality of silicon steel sheet cores capable of controlling the suspension position of the rotor body are arranged in the electromagnetic jacket. Two groups of protection frame assemblies are arranged at both ends of the rotor body. Each group of protection frame assemblies is mounted on the protection bottom plate. A horizontally movable strip gear is arranged below each group of protection frame assemblies on the same side. The plurality of silicon steel sheet cores and the magnetically adjustable enameled wire winding in the electromagnetic jacket control the suspension of the rotor body. When the rotor body is running at high speed, the four groups of protection frame assemblies at the front and rear ends of the rotor body can be used for clamping to prevent the rotor body from being deflected and keep the center of the rotor body. The double mechanism of positioning and clamping is adopted, so that the operation and disassembly of the rotor body can be quickly maintained.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of motor parts, more specifically, relates to a magnetic rotor protection structure for printing. BACKGROUND

[0002] In the field of motor rotor installation, positioning and operation maintenance, traditional technical means have many drawbacks, which seriously affect the performance, stability and maintenance convenience of the motor.

[0003] Traditional rotor installation methods often lack precise and efficient positioning mechanisms. When installing the rotor body into electromagnetic sleeves and other devices, it is often difficult to quickly find the center position, the positioning process is tedious and time-consuming, resulting in low assembly efficiency. Moreover, due to the lack of effective initial positioning auxiliary structure, when relying on electromagnetic force to control the rotor, the positioning time is long, affecting the overall installation process.

[0004] During the operation of the rotor, preventing the rotor from tilting is a key issue, but the traditional method is not effective. When the rotor is running at high speed, it is difficult to effectively clamp the rotor by relying on simple fixing methods, which cannot ensure that the rotor is always in the center position, and tilting is likely to occur, which not only reduces the performance of the motor, but also may cause mechanical failure and shorten the service life of the motor.

[0005] In addition, the traditional cooling method has shortcomings for the heat generated by the motor rotor during operation. If the heat generated by the rotor during operation cannot be dissipated in time, it will cause the temperature of the motor to be too high, affecting the performance and reliability of the motor. However, the traditional cooling system may not be able to fully utilize the space and airflow around the rotor, and the cooling efficiency is low, which cannot effectively cool the rotor.

[0006] During equipment maintenance and handling, the protection of the rotor by the traditional method is also not perfect. During maintenance, the rotor is easy to be damaged due to shaking; during equipment handling, debugging or standby state, there is a lack of reliable mechanical locking device, and the rotor may fall due to vibration or accidental touch, causing damage.

[0007] Moreover, when the rotor has machining errors or installation deviations, the traditional clamp is difficult to adaptively adjust the clamping direction. The traditional clamp is usually a fixed structure that needs to be adjusted repeatedly to adapt to rotors in different states, which not only complicates the operation, but also makes it difficult to ensure the accuracy and stability of clamping, affecting the overall performance of the motor. SUMMARY

[0008] In order to solve the above technical problems, the present application provides a magnetic rotor protection structure for printing to solve the above problems.

[0009] The utility model provides a kind of magnetic rotor protection structure for printing, including protection base plate and rotor body, support shell is provided above the protection base plate, the inside of the support shell is provided with electromagnetic jacket, the inside of the electromagnetic jacket is provided with multiple silicon steel sheet cores that can control the suspension position of rotor body, the both ends of the rotor body are provided with two groups of protection frame components, and each group of protection frame components is mounted on protection base plate, and the same side each group of protection frame components below is provided with horizontally movable bar gear, bar gear is used to adjust the rotation angle of protection frame component, each group of protection frame components includes rotating arm, the end of each rotating arm is provided with joint frame, and the end of each joint frame is movably provided with ball head frame, and ball head frame is used to position rotor body.

[0010] Preferably, each of the silicon steel sheet cores is fixed to the inner wall of the electromagnetic jacket, the surface of each of the silicon steel sheet cores is provided with a wire-wound coil, and each two silicon steel sheet cores are electromagnetically connected, the inside of the electromagnetic jacket is provided with three concentric guide columns, the end of each of the guide columns is located inside the electromagnetic jacket, and a first spring is fixedly installed between the end of each guide column and the inside of the electromagnetic jacket, the outer ring of the rotor body is provided with a positioning groove, the end of each of the guide columns is tapered, and the end of each of the guide columns is located inside the positioning groove.

[0011] Preferably, each of the rotating arms is fixedly installed with a fixed shaft at the bottom corner, and a gear is fixedly installed outside each of the fixed shafts, each of the gears is engaged with the bar gear below, the end of each of the bar gears is fixedly installed with an auxiliary push plate, a push frame is movably attached between the two auxiliary push plates, the back of the push frame is provided with a driving assembly, the threaded rod at the end of the output shaft of the driving assembly penetrates through the outside of the push frame, a second spring is fixedly installed between the other end of each of the bar gears and the side wall of the protection base plate, the motor part of each of the driving assemblies is fixed to the protection base plate, each of the auxiliary push plates is triangular, each of the push frames is isosceles trapezoidal, and the inclined surface of each of the auxiliary push plates is attached to the waist surface of the push frame, the inside of each of the rotating arms is provided with a cooling liquid groove, and the end of the cooling liquid groove is provided with a sealing cover, the side of each of the rotating arms is provided with a cooling bin, and the cooling bin is communicated with the cooling liquid groove in the rotating arm through a hose.

[0012] Preferably, the lower end of each ball head frame is fixedly installed with a connecting column, the lower end of each connecting column is fixedly installed with a bottom ball, each bottom ball is movably installed in the joint frame, the lower end of each bottom ball is fixedly installed with a movable plate, a heat dissipation copper rod is installed through the ball head frame, the connecting column and the bottom ball, and the heat dissipation copper rod is installed in the cooling liquid tank in the rotating arm, the joint frame is fixedly installed with a slide rail frame near the bottom opening, the inner walls of the slide rail frame are rotatably installed with arc-shaped slides, the front and rear of the slide rail frame are fixedly installed with support frames, the third springs are fixedly installed between the two sides of each support frame and the arc-shaped slides, and the fourth springs are fixedly installed between the two sides of each movable plate and the two arc-shaped slides.

[0013] Compared with the prior art, the present application has the following beneficial effects:

[0014] In the present application, each set of protection frame assembly includes a rotating arm, the end of each rotating arm is provided with a joint frame, the end of each joint frame is movably provided with a ball head frame, the ball head frame is used for positioning the rotor body, when the rotor body is installed, the rotor body is inserted into the electromagnetic jacket, the electromagnetic jacket is started, the multiple silicon steel sheet cores and the enameled wire winding in the electromagnetic jacket are magnetically adjusted, the rotor body is controlled to be suspended, when the rotor body is operated at high speed, the four sets of protection frame assemblies at the front and rear ends of the rotor body can be used for clamping to prevent the rotor body from being deflected and keep the center of the rotor body, and the positioning and clamping double mechanisms are adopted, so that the operation and disassembly of the rotor body can be quickly kept.

[0015] In the present application, the end of each guide column is located in the electromagnetic jacket, a first spring is fixedly installed between the end of each guide column and the electromagnetic jacket, the outer ring of the rotor body is provided with a positioning groove, the end of each guide column is conical, and the end of each guide column is located in the positioning groove, after the rotor body is installed in the multiple electromagnetic jackets, the positioning groove on the surface of the rotor body is located between the three guide columns, the three guide columns can help the rotor body to be initially positioned, the ends of the three guide columns are provided with the first springs, the initial center alignment of the guide columns can be helped, the silicon steel sheet cores and the enameled wire winding can drive the rotor body, the positioning time can be effectively shortened, and after the electromagnetic jacket is powered off, the three guide columns can play an auxiliary supporting role, so that the rotor body is prevented from suddenly falling and being damaged by knocking.

[0016] In the application, the pushing frame moves to drive the auxiliary pushing plates on both sides to move, the auxiliary pushing plates on both sides move synchronously to drive the bar gears on both sides to move to both sides, the movement of the bar gears drives the second spring at the tail end to compress, the gear meshes with the bar gear, so the gear drives the rotating arm to rotate, the two rotating arms synchronously drive the ball head frame to rotate to approach the rotor body, the ball head frame contacts the surface of the rotor body, clamping and positioning are completed, when subsequent shutdown maintenance is performed, the rotor body can also be prevented from shaking, when the equipment is carried, debugged or on standby, the holding frame assembly provides mechanical locking to avoid the rotor body from falling due to vibration or accidental touch, when the rotor body is installed, the symmetrical clamping of the holding frame assembly can assist in completing accurate centering to improve assembly efficiency, when the rotor body operates, the driving assembly is started to open the ball head frames on both sides, the ball head frames on both sides are separated from the rotor body.

[0017] In the application, the cooling bin is communicated with the cooling liquid tank in the rotating arm through the hose, when in use, the rotor body is separated from the rotor body when operating at high speed, but is close to the rotor body, on one hand, the rotor body can be prevented from falling when eccentric, on the other hand, the rotor body generates heat when operating, and the rotation of the rotor body drives the nearby air to circulate, the heat radiation contacts the ball head frame, the heat is absorbed by the ball head frame and is transmitted to the heat dissipation copper rod, the heat dissipation copper rod transmits the heat to the cooling liquid tank, the cooling liquid in the cooling liquid tank absorbs the heat, so that the rotor body can be cooled.

[0018] In the application, the ball head frame can drive the bottom ball to move through the connecting column, the bottom ball drives the movable plate to deflect and rotate in the joint frame, the movable plate moving drives the fourth spring on both sides to compress, the fourth spring can provide a reaction force to the ball head frame, and the movable plate can drive the arc-shaped slide rail to slightly rotate when being stressed, the arc-shaped slide rail rotates in the slide rail frame, and the arc-shaped slide rail is subjected to the reaction force of the third spring on both sides, when the rotor body has machining errors or installation deviations, the bottom ball can swing around the ball center, automatically adjusts the clamping direction, so that the ball head frame is always perpendicular to the rotor axis, and the flexible connection can improve the connection accuracy between the ball head frame and the rotor body, and the adjustable ball head frame can improve the clamping speed when clamping the rotor body, without repeatedly adjusting like the traditional clamp. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a holding bottom plate structure schematic diagram of the application;

[0020] Figure 2 is an electromagnetic jacket structure schematic diagram of the application;

[0021] Figure 3 is a guide column structure schematic diagram of the application;

[0022] Figure 4 is a rotating arm structure schematic diagram of the application;

[0023] Figure 5 is a schematic diagram of the overall structure of the holder assembly of the present application;

[0024] Figure 6 is a schematic diagram of the pusher frame structure of the present application;

[0025] Figure 7 is a schematic diagram of the joint frame structure of the present application;

[0026] Figure 8 is a schematic diagram of the ball head frame structure of the present application;

[0027] Figure 9 is a schematic diagram of the bottom ball structure of the present application.

[0028] In the figure, the correspondence between the component names and the reference numerals is as follows: 1, holder bottom plate; 11, holder assembly; 12, support shell; 13, rotor body; 14, positioning groove; 16, electromagnetic jacket; 18, guide column; 19, first spring; 2, silicon steel sheet core; 21, enameled wire winding; 22, rotating arm; 23, fixed shaft; 24, gear; 25, cooling bin; 26, driving assembly; 27, pusher frame; 28, strip gear; 29, auxiliary push plate; 3, cooling liquid tank; 31, joint frame; 32, connecting column; 33, ball head frame; 34, movable plate; 35, heat dissipation copper pole; 36, bottom ball; 37, slide rail frame; 38, arc-shaped slide frame; 39, support frame; 4, third spring; 41, fourth spring. DETAILED DESCRIPTION

[0029] The embodiments of the present application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0030] Please refer to Figures 1-9The application provides a magnetic rotor protection structure for printing, which comprises a protection base plate 1 and a rotor body 13, a support shell 12 is arranged above the protection base plate 1, at least two electromagnetic cladding sleeves 16 are arranged in the support shell 12, a plurality of silicon steel sheet cores 2 capable of controlling the suspension position of the rotor body 13 are arranged in the electromagnetic cladding sleeves 16, two groups of protection frame assemblies 11 are arranged at the two ends of the rotor body 13, each group of protection frame assemblies 11 is installed on the protection base plate 1, a horizontally movable strip-shaped gear 28 is arranged below each group of protection frame assemblies 11 on the same side, the strip-shaped gear 28 is used for adjusting the rotation angle of the protection frame assembly 11, each protection frame assembly 11 comprises a rotating arm 22, a joint frame 31 is arranged at the end of each rotating arm 22, a ball head frame 33 is movably arranged at the end of each joint frame 31, and the ball head frame 33 is used for positioning the rotor body 13; when the rotor body 13 is installed, the rotor body 13 is inserted into the electromagnetic cladding sleeve 16, the electromagnetic cladding sleeve 16 is started, the plurality of silicon steel sheet cores 2 and the enameled wire winding 21 in the electromagnetic cladding sleeve 16 are magnetically adjusted, and the rotor body 13 is controlled to be suspended; when the rotor body 13 is operated at a high speed, the four groups of protection frame assemblies 11 at the front and rear ends of the rotor body 13 can be used for clamping and preventing the rotor body 13 from being deflected, so that the center of the rotor body 13 is kept; the positioning and clamping double mechanisms are adopted, so that the operation and disassembly of the rotor body 13 can be quickly kept.

[0031] Each silicon steel sheet core 2 is fixed to the inner wall of the electromagnetic cladding sleeve 16, the surface of each silicon steel sheet core 2 is provided with an enameled wire winding 21, and each two silicon steel sheet cores 2 are electromagnetically connected; the inside of the electromagnetic cladding sleeve 16 is provided with three concentric guide columns 18, the end of each guide column 18 is located in the inside of the electromagnetic cladding sleeve 16, and a first spring 19 is fixedly installed between the end of each guide column 18 and the inside of the electromagnetic cladding sleeve 16; the outer ring of the rotor body 13 is provided with a positioning groove 14, the end of each guide column 18 is tapered, and the end of each guide column 18 is located in the inside of the positioning groove 14; after the rotor body 13 is installed in the plurality of electromagnetic cladding sleeves 16, the positioning groove 14 arranged on the surface of the rotor body 13 is located between the three guide columns 18, the three guide columns 18 can help the rotor body 13 to be initially positioned, the ends of the three guide columns 18 are provided with the first springs 19, the guide columns 18 can be initially centered, the rotor body 13 is driven by the silicon steel sheet cores 2 and the enameled wire windings 21, the positioning time can be effectively shortened, and the three guide columns 18 can assist in supporting after the electromagnetic cladding sleeve 16 is powered off, so that the rotor body 13 is prevented from suddenly falling and being damaged by collision.

[0032] The fixed shaft 23 is fixedly installed at the bottom corner of each rotating arm 22, the gear 24 is fixedly installed outside each fixed shaft 23, the lower portion of each gear 24 is engaged with the strip-shaped gear 28, the end portion of each strip-shaped gear 28 is fixedly installed with the auxiliary push plate 29, the push frame 27 is movably attached between the two auxiliary push plates 29, the drive assembly 26 is arranged on the back of the push frame 27, the threaded rod at the output shaft end of the drive assembly 26 penetrates through the push frame 27, the second spring is fixedly installed between the other end of each strip-shaped gear 28 and the side wall of the holding bottom plate 1, the motor portion of each drive assembly 26 is fixed to the holding bottom plate 1, each auxiliary push plate 29 is triangular, each push frame 27 is isosceles trapezoidal, and the inclined surface of each auxiliary push plate 29 is attached to the waist surface of the push frame 27. In use, the two ball head frames 33 are located on both sides of the rotor body 13, the user needs to smear silicone grease on the surface of the ball head frame 33, starts the drive assembly 26 (the drive assembly 26 is composed of a motor and a threaded rod, the threaded rod is fixed to the output shaft end of the drive assembly 26), the drive assembly 26 drives the push frame 27 to move through the threaded rod, the push frame 27 drives the auxiliary push plates 29 on both sides to move, the auxiliary push plates 29 on both sides move synchronously and drive the strip-shaped gears 28 on both sides to move to both sides, the strip-shaped gears 28 move to compress the second springs at the ends, the gears 24 are engaged with the strip-shaped gears 28, so the gears 24 drive the rotating arms 22 to rotate, the two rotating arms 22 synchronously drive the ball head frames 33 to rotate and approach the rotor body 13, the ball head frames 33 contact the surface of the rotor body 13, and clamping and positioning are completed. In subsequent shutdown maintenance, the rotor body 13 can also be prevented from shaking, in equipment carrying, debugging or standby, the holding frame assembly 11 provides mechanical locking to avoid the rotor body 13 from falling due to vibration or mistaken touch, when the rotor body 13 is installed, the symmetrical clamping of the holding frame assembly 11 can assist in completing accurate centering, improving assembly efficiency, and when the rotor body 13 operates, the drive assembly 26 is started to open the ball head frames 33 on both sides, and the ball head frames 33 on both sides are separated from the rotor body 13.

[0033] The lower end of each ball head frame 33 is fixedly installed with a connecting column 32, the lower end of each connecting column 32 is fixedly installed with a bottom ball 36, each bottom ball 36 is movably installed in the joint frame 31, the lower end of each bottom ball 36 is fixedly installed with a movable plate 34, a heat dissipation copper rod 35 is installed through the ball head frame 33, the connecting column 32 and the bottom ball 36, and the heat dissipation copper rod 35 is installed in the cooling liquid groove 3 in the rotating arm 22, the inside of each rotating arm 22 is provided with a cooling liquid groove 3, and the end of the cooling liquid groove 3 is provided with a sealing cover, the side of each rotating arm 22 is provided with a cooling bin 25, and the cooling bin 25 is communicated with the cooling liquid groove 3 in the rotating arm 22 through a hose, in use, when the rotor body 13 rotates at high speed, each ball head frame 33 is separated from the rotor body 13, but is close to the rotor body 13, on the one hand, it can prevent the rotor body 13 from falling when it is eccentric, and on the other hand, the rotor body 13 generates heat when it rotates, and the rotation of the rotor body 13 drives the nearby air to circulate, the heat radiation contacts the ball head frame 33, the heat is absorbed by the ball head frame 33 and transferred to the heat dissipation copper rod 35, the heat dissipation copper rod 35 transfers the heat to the cooling liquid groove 3, and the cooling liquid in the cooling liquid groove 3 absorbs the heat, so that the rotor body 13 can be cooled.

[0034] The joint frame 31 is fixedly installed with a sliding rail frame 37 near the bottom opening, the inner walls of the two sides of the sliding rail frame 37 are rotatably installed with arc-shaped sliding frames 38, the front and back of the sliding rail frame 37 are fixedly installed with support frames 39, the two sides between each support frame 39 and the arc-shaped sliding frame 38 are fixedly installed with third springs 4, and the two sides between each movable plate 34 and the two arc-shaped sliding frames 38 are fixedly installed with fourth springs 41, in use, when the ball head frame 33 clamps the rotor body 13, the ball head frame 33 can drive the bottom ball 36 to move by the connecting column 32, the bottom ball 36 drives the movable plate 34 to deviate and rotate in the joint frame 31, the movable plate 34 drives the two fourth springs 41 to compress, the fourth springs 41 can provide a reaction force to the ball head frame 33, and the movable plate 34 can drive the arc-shaped sliding frame 38 to slightly rotate when it is stressed, the arc-shaped sliding frame 38 rotates in the sliding rail frame 37, and the arc-shaped sliding frame 38 is subjected to the reaction force of the two third springs 4, when the rotor body 13 has machining errors or installation deviations, the bottom ball 36 can swing around the ball center, automatically adjusts the clamping direction, so that the ball head frame 33 is always perpendicular to the rotor axis, and the flexible connection can improve the connection accuracy between the ball head frame 33 and the rotor body 13, and the adjustable ball head frame 33 can improve the clamping speed when clamping the rotor body 13, without repeatedly adjusting like traditional clamps.

[0035] The embodiments of the present application are presented by way of example and description, and are not intended to be exhaustive or to limit the application to the form disclosed. Many modifications and variations will be apparent to those skilled in the art. Embodiments are chosen and described in order to best explain the principles of the application and its practical application, and to thereby enable others skilled in the art to best utilize the application in various embodiments and with various modifications as are suited to the particular use contemplated.

Claims

1. A magnetic rotor holding structure for printing, comprising a holding base plate (1) and a rotor body (13), characterized in that: The upper of the protection base plate (1) is provided with a support shell (12), the inside of the support shell (12) is provided with an electromagnetic jacket (16), the inside of the electromagnetic jacket (16) is provided with a plurality of silicon steel sheet cores (2) capable of controlling the suspension position of the rotor body (13), both ends of the rotor body (13) are provided with two groups of protection frame assemblies (11), and each group of protection frame assemblies (11) is installed on the protection base plate (1), and the same side of each group of protection frame assemblies (11) is provided with a horizontally movable strip gear (28) below, the strip gear (28) is used for adjusting the rotation angle of the protection frame assembly (11), each group of protection frame assemblies (11) comprises a rotating arm (22), the end of each rotating arm (22) is provided with a joint frame (31), the end of each joint frame (31) is movably provided with a ball head frame (33), and the ball head frame (33) is used for positioning the rotor body (13).

2. The magnetic rotor guard structure for printing as claimed in claim 1, wherein, Each of the silicon steel sheet cores (2) is fixed to the inner wall of the electromagnetic jacket (16), the surface of each of the silicon steel sheet cores (2) is provided with an enameled wire winding (21), and every two silicon steel sheet cores (2) are electromagnetically connected, and the inside of the electromagnetic jacket (16) is provided with three concentric guide columns (18).

3. The magnetic rotor retaining structure for printing as claimed in claim 2, wherein The end of each guide column (18) is located inside the electromagnetic jacket (16), and a first spring (19) is fixedly installed between the end of each guide column (18) and the inside of the electromagnetic jacket (16).

4. The magnetic rotor retaining structure for printing as claimed in claim 3, wherein The outer ring of the rotor body (13) is provided with a positioning groove (14), and the end of each guide column (18) is tapered and located inside the positioning groove (14).

5. The magnetic rotor retaining structure for printing as defined in claim 1, wherein Each of the rotating arms (22) is fixedly installed with a fixed shaft (23) at the bottom corner, a gear (24) is fixedly installed outside each fixed shaft (23), and each gear (24) is meshed with the strip gear (28) below.

6. The magnetic rotor retaining structure for printing as defined in claim 5, wherein The end of each strip gear (28) is fixedly installed with an auxiliary push plate (29), and the auxiliary push plates (29) are movably attached with a push frame (27) between, and the back of the push frame (27) is provided with a driving assembly (26), and the threaded rod at the output shaft end of the driving assembly (26) penetrates the outside of the push frame (27).

7. The magnetic rotor retaining structure for printing as claimed in claim 6, wherein Each strip gear (28) is fixedly installed with a second spring between the other end and the side wall of the protection base plate (1), the motor part of each driving assembly (26) is fixed to the protection base plate (1), each auxiliary push plate (29) is triangular, each push frame (27) is isosceles trapezoidal, and the inclined surface of each auxiliary push plate (29) is attached to the waist surface of the push frame (27).

8. The magnetic rotor retaining structure for printing as claimed in claim 7, wherein The inside of each rotating arm (22) is provided with a cooling liquid groove (3), and the end of the cooling liquid groove (3) is provided with a sealing cover, and the side edge of each rotating arm (22) is provided with a cooling bin (25), and the cooling bin (25) is communicated with the cooling liquid groove (3) in the rotating arm (22) through a hose.

9. The magnetic rotor retaining structure for printing as claimed in claim 8, wherein The lower end of each ball head frame (33) is fixedly installed with a connecting column (32), the lower end of each connecting column (32) is fixedly installed with a bottom ball (36), each bottom ball (36) is movably installed inside the joint frame (31), the lower end of each bottom ball (36) is fixedly installed with a movable plate (34), and a heat dissipation copper pole (35) is installed through the ball head frame (33), the connecting column (32) and the bottom ball (36), and the heat dissipation copper pole (35) is installed in the cooling liquid groove (3) inside the rotating arm (22).

10. The magnetic rotor retaining structure for printing as claimed in claim 9, wherein The joint frame (31) is fixedly installed with a sliding rail frame (37) near the bottom opening, arc-shaped sliding frames (38) are rotatably installed on the inner walls of the two sides of the sliding rail frame (37), support frames (39) are fixedly installed on the front and back of the sliding rail frame (37), third springs (4) are fixedly installed between each support frame (39) and the arc-shaped sliding frames (38) on the two sides, and fourth springs (41) are fixedly installed between each movable plate (34) and the two arc-shaped sliding frames (38) on the two sides.

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