High-rigidity horizontal box type spindle structure

Abstract

The invention discloses a high-rigidity horizontal box type spindle structure, which relates to the technical field of machine tools, and comprises a frame and a spindle box main body, a sliding mechanism is arranged in the frame, the frame is mounted and positioned on a reference plane through a Y-axis positioning block, and the spindle box main body is mounted on the frame through a Y-axis positioning block. The Z-axis positioning block carries out Z-direction datum plane positioning on the spindle box body through a guide rail and a guide block, the Y-axis direction movement achieves simultaneous movement of the spindle body in two directions through a Y-axis lead screw connector and a Y-axis lead screw stroke kinematic pair, a limiting boss is designed at the bottom of the machine frame to serve as hard limiting at one end of the Y axis, and auxiliary support installation faces are symmetrically designed on the rear side of the machine frame. The auxiliary support can be installed on the rear side of the machine frame to further stabilize the position of the machine frame, a grating ruler can be additionally installed through the grating ruler installation face to improve the Y-axis machining precision, the machine frame is an integrated casting, structural ribs are adopted at multiple positions to enhance the overall rigidity, and errors generated in the machining and assembling process are reduced.

Description

Technical Field

[0001] This invention relates to the field of machine tool technology, specifically to a high-rigidity horizontal machining center spindle structure. Background Technology

[0002] In the use of existing high-rigidity horizontal machining center spindles, the spindle position is prone to instability when it extends to its limit, which affects the rigidity of the spindle and makes it difficult to guarantee the accuracy requirements during machining.

[0003] Combining the above issues, we find that existing products on the market are difficult to avoid all of these problems simultaneously. Even if they can be solved, they require external tools, which fails to achieve the desired effect. Therefore, we propose a high-rigidity horizontal spindle with a box-type spindle structure. Summary of the Invention

[0004] The purpose of this invention is to provide a high-rigidity horizontal spindle structure with a box-type spindle to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A high-rigidity horizontal spindle structure includes a frame and a spindle box body. The frame is provided with a sliding mechanism that works in conjunction with the spindle box body. A spindle sleeve is fixedly sleeved inside the spindle box body, and the spindle body is drivenly connected inside the spindle sleeve. The sliding mechanism includes a guide block, which is fixedly installed on the side of the spindle box body opposite to the frame. A guide rail is fixedly installed inside the frame, and the guide block is slidably sleeved inside the guide rail. A Z-axis positioning block is fixedly installed inside the frame and works in conjunction with the guide rail. A positioning component is provided inside the guide rail and works in conjunction with the guide block. A transmission component is provided on one side of the frame and works in conjunction with the spindle body.

[0006] Preferably, a lead screw interface is provided on one side of the frame, a grating ruler mounting surface is fixedly installed on the inner wall of the frame, a Y-axis positioning block is fixedly installed on one side of the frame, limit bosses are fixedly installed on both sides of the bottom of the frame, a distributor mounting surface is fixedly installed on the bottom of the frame, and a secondary bracket mounting surface is fixedly installed on both sides of the frame.

[0007] Preferably, the surface of the guide block is provided with a pressure groove, and a pressure strip is fixedly installed on the inner wall of the guide rail, with the surface of the pressure strip slidably connected to the inner cavity of the pressure groove.

[0008] Preferably, the positioning assembly comprises a cavity, the cavity is arranged in the inside of the guide rail, a positioning column is sleeved in the inside of the cavity, one end of the positioning column penetrates through the guide rail and is in sliding connection with the inner cavity of the guide rail, a plurality of positioning grooves are arranged on the side opposite to the guide rail of the guide block, the positioning column is used in cooperation with the positioning grooves, a electric push rod is fixedly installed in the inside of the cavity, a push frame is fixedly connected to the telescopic end of the electric push rod, an opening is arranged on one side of the positioning column, one end of the push frame penetrates through the opening and is in sliding connection with the inner cavity of the opening, a top block is fixedly installed in the inside of the opening, and the push frame is used in cooperation with the top block.

[0009] Preferably, a horizontal rod is fixedly installed in the inside of the top block, and a plurality of rollers are rotatably sleeved on the surface of the horizontal rod and used in cooperation with the push frame.

[0010] Preferably, a supporting rod is fixedly connected to the inside of the cavity, and one end of the supporting rod penetrates through the positioning column and is in sliding connection with the inner cavity of the positioning column.

[0011] Preferably, a supporting block is fixedly installed at one end of the supporting rod, a supporting groove is arranged in the inside of the positioning column, and the supporting block is in sliding connection with the inside of the supporting groove.

[0012] Preferably, a limiting rod is fixedly connected to one end of the push frame, one end of the limiting rod penetrates through the guide rail and is in sliding connection with the inner cavity of the guide rail.

[0013] Preferably, a limiting block is fixedly installed at one end of the limiting rod, a limiting groove is arranged in the inside of the guide rail, and the limiting block is in sliding connection with the inside of the limiting groove.

[0014] Preferably, the transmission assembly comprises a fixing frame, the fixing frame is fixedly installed on one side of the rack, a hydraulic cylinder is fixedly installed in the inside of the fixing frame, a transmission shaft is fixedly connected to the telescopic end of the hydraulic cylinder, a connecting frame and a shaft seat are fixedly installed on the side opposite to the rack of the main shaft box body, one end of the transmission shaft penetrates through the shaft seat and is in sliding connection with the inner cavity of the shaft seat, and one end of the transmission shaft is fixedly sleeved in the inside of the connecting frame.

[0015] Compared with the prior art, the present application has the following advantages: 1. The rack of the present application is positioned on the reference surface through the Y-axis positioning block, and the Z-axis positioning block positions the main shaft box body in the Z-direction reference surface through the guide rail and guide block, the Y-axis direction movement is realized through the Y-axis screw interface and Y-axis screw stroke movement pair, the two directions of the main shaft body are simultaneously moved, the limit boss is designed at the bottom of the rack as the hard limit of one end of the Y-axis, the vice support mounting surface is symmetrically designed at the rear side of the rack, the vice support can be installed at the rear side of the rack to further stabilize the position of the rack, the grating ruler can be installed through the grating ruler mounting surface to improve the machining precision of the Y-axis, the rack is an integral casting and structural ribs are used at many places to enhance the overall rigidity, and the error generated during machining and assembly is reduced.

[0016] 2. The present application stabilizes the position of the guide rail through the Z-axis positioning block by increasing the length of the guide block, so as to stabilize the position of the main shaft box body through the guide rail and guide block, the main shaft body can still maintain good rigidity under the driving of the transmission assembly and stretching out to the limit state, and the precision requirement during machining is guaranteed. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the overall structure schematic diagram of the present application; Figure 2 It is the rack structure schematic diagram of the present application; Figure 3 It is the rack structure schematic diagram of the present application; Figure 4 It is the sliding mechanism structure schematic diagram of the present application; Figure 5 It is the transmission assembly structure schematic diagram of the present application; Figure 6 It is the guide rail structure schematic diagram of the present application; Figure 7 It is the positioning assembly structure schematic diagram of the present application; Figure 8 It is the push rack structure schematic diagram of the present application; Figure 9 It is the positioning column structure schematic diagram of the present application.

[0018] In the figure: 1, rack; 101, screw rod interface; 102, grating ruler installation surface; 103, Y axis positioning block; 104, limiting boss; 105, distributor installation surface; 106, auxiliary support installation surface; 11, main shaft box main body; 1101, main shaft sleeve; 1102, main shaft main body; 2, sliding mechanism; 21, guide block; 22, guide rail; 2201, pressing strip; 2202, pressing groove; 23, Z axis positioning block; 24, transmission assembly; 2401, fixed frame; 2402, hydraulic cylinder; 2403, transmission shaft; 2404, connecting frame; 2405, shaft seat; 25, positioning assembly; 2501, cavity; 2502, positioning column; 2503, positioning groove; 2504, electric push rod; 2505, push frame; 2506, opening; 2507, top block; 2508, cross bar; 2509, roller; 2510, support rod; 2511, support block; 2512, support groove; 2513, limiting rod; 2514, limiting block; 2515, limiting groove. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0020] Embodiment 1: Please refer to Figures 1-9 The present application provides a technical solution: a high-rigidity horizontal box type main shaft structure, comprising a rack 1 and a main shaft box main body 11. The inside of the rack 1 is provided with a sliding mechanism 2, which is used in cooperation with the main shaft box main body 11. The inside of the main shaft box main body 11 is fixedly sleeved with a main shaft sleeve 1101, and the inside of the main shaft sleeve 1101 is drivingly connected with a main shaft main body 1102. The main shaft box main body 11 is designed with an extension support structure on one side, which increases the length of the main shaft box main body 11. The sliding mechanism 2 includes a guide block 21, which is fixedly installed on the side of the spindle box body 11 opposite to the frame 1. A guide rail 22 is fixedly installed inside the frame 1, and the guide block 21 is slidably sleeved inside the guide rail 22. A Z-axis positioning block 23 is fixedly installed inside the frame 1 and works in conjunction with the guide rail 22. A positioning component 25 is provided inside the guide rail 22 and works in conjunction with the guide block 21. A transmission component 24 is provided on one side of the frame 1 and works in conjunction with the spindle body 1102. A lead screw interface 101 is provided on one side of the frame 1. A grating ruler mounting surface 102 is fixedly installed on the inner wall of the frame 1. A Y-axis positioning block 103 is fixedly installed on one side of the frame 1. Limit bosses 104 are fixedly installed on both sides of the bottom of the frame 1. A distributor mounting surface 105 is fixedly installed on the bottom of the frame 1. A secondary support mounting surface 106 is fixedly installed on both sides of the frame 1. The frame 1 is mounted and positioned on the reference surface by the Y-axis positioning block 103, and the Z-axis positioning block 23 positions the spindle box body 11 on the Z-axis reference surface through the guide rail 22 and the guide block 21. The Y-axis movement is achieved by the Y-axis lead screw interface and the Y-axis lead screw travel motion pair, realizing the simultaneous movement of the spindle body 1102 in two directions. A limiting boss 104 is designed at the bottom of the frame 1 as a hard limit at one end of the Y-axis. A secondary bracket mounting surface 106 is symmetrically designed on the rear side of the frame 1, which can be used to install a secondary bracket on the rear side of the frame 1 to further stabilize the position of the frame 1. The position is determined by a grating ruler. Mounting surface 102 can be fitted with a grating ruler to improve Y-axis machining accuracy. The frame 1 is an integral casting with structural ribs in multiple places to enhance overall rigidity. The spindle box body 11 can be moved inside the frame 1 by the transmission component 24. By increasing the length of the guide block 21, the position of the guide rail 22 is stabilized by the Z-axis positioning block 23. The position of the spindle box body 11 can be stabilized by the guide rail 22 and the guide block 21. Under the drive of the transmission component 24, the spindle body 1102 can still maintain good rigidity even when extended to the limit, ensuring the accuracy requirements during machining.

[0021] As a further limitation of the sliding mechanism 2 of the present invention, the surface of the guide block 21 is provided with a pressure groove 2202, and the inner wall of the guide rail 22 is fixedly installed with a pressure strip 2201. The surface of the pressure strip 2201 is slidably connected to the inner cavity of the pressure groove 2202. By providing a pressure groove 2202 on the surface of the guide block 21 and installing a pressure strip 2201 on the inner wall of the guide rail 22, the accuracy of the position of the guide block 21 inside the guide rail 22 is improved by the pressure strip 2201 and the pressure groove 2202, thereby ensuring the accuracy of the position of the main spindle box body 11.

[0022] The specific implementation of this embodiment is as follows: The frame 1 is mounted and positioned on the reference surface by the Y-axis positioning block 103, and the Z-axis positioning block 23 positions the spindle box body 11 on the Z-axis reference surface through the guide rail 22 and the guide block 21. The Y-axis movement is achieved by the Y-axis lead screw interface and the Y-axis lead screw travel motion pair, realizing the simultaneous movement of the spindle body 1102 in two directions. A limiting boss 104 is designed at the bottom of the frame 1 as a hard limit at one end of the Y-axis. A secondary bracket mounting surface 106 is symmetrically designed on the rear side of the frame 1, which can be installed on the rear side of the frame 1 to further stabilize the position of the frame 1. A grating ruler can be added through the grating ruler mounting surface 102 to improve the Y-axis machining accuracy. The frame 1 is an integral casting and uses structural ribs in many places to enhance the overall rigidity. The main spindle body 11 can be driven by the transmission component 24. The spindle box body 11 moves inside the frame 1, causing the guide block 21 to slide inside the guide rail 22. The position of the guide block 21 is stabilized by the pressure groove 2202 and the pressure strip 2201 to ensure the accuracy of the spindle box body 11 during movement. After the spindle box body 11 is moved to the required position, the guide block 21 is positioned by the positioning component 25 to further stabilize the position of the spindle box body 11, thereby effectively stabilizing the position of the spindle body 1102. By increasing the length of the guide block 21 and stabilizing the position of the guide rail 22 by the Z-axis positioning block 23, the position of the spindle box body 11 can be stabilized by the guide rail 22 and the guide block 21. Under the drive of the transmission component 24, the spindle body 1102 can maintain good rigidity even when extended to its limit, ensuring the accuracy requirements during machining.

[0023] Example 2: Please refer to Figures 1-9 The present invention provides a technical solution: a high-rigidity horizontal and box-type spindle structure, which makes corresponding improvements to the technical problems mentioned in the background art.

[0024] As a further definition of the sliding mechanism 2 of the present invention, the positioning component 25 includes a cavity 2501, which is formed inside the guide rail 22. A positioning post 2502 is slidably fitted inside the cavity 2501. One end of the positioning post 2502 passes through the guide rail 22 and is slidably connected to the inner cavity of the guide rail 22. A plurality of positioning grooves 2503 are formed on the side of the guide block 21 opposite to the guide rail 22. The positioning post 2502 and the positioning grooves 2503 are used in conjunction. An electric push rod 2504 is fixedly installed inside the cavity 2501. A push frame 2505 is fixedly connected to the telescopic end of the electric push rod 2504. An opening 2506 is formed on one side of the positioning post 2502. One end of the push frame 2505 passes through the opening 2506 and is slidably connected to the inner cavity of the opening 2506. A top block 2507 is fixedly installed inside the opening 2506. The push frame 2505 and the top block 2507 are slidably connected to the top block 2507. The top block 2507 is used in conjunction with the top block 2507; a crossbar 2508 is fixedly installed inside the top block 2507, and a roller 2509 is rotatably sleeved on the surface of the crossbar 2508. The roller 2509 is used in conjunction with the pusher 2505. After the spindle box body 11 is moved to the required position, the pusher 2505 is moved by the electric push rod 2504, so that the pusher 2505 moves inside the opening 2506 and contacts the roller 2509. The pusher 2505 pushes the top block 2507 through the roller 2509 and the crossbar 2508, so that the top block 2507 drives the positioning column 2502 to move, so that one end of the positioning column 2502 extends into the interior of the positioning groove 2503. Thus, the positioning component 25 positions the guide block 21, further stabilizing the position of the spindle box body 11, thereby effectively stabilizing the position of the spindle body 1102.

[0025] A support rod 2510 is fixedly connected inside the cavity 2501. One end of the support rod 2510 passes through the positioning post 2502 and is slidably connected to the inner cavity of the positioning post 2502. A support block 2511 is fixedly installed at one end of the support rod 2510. A support groove 2512 is opened inside the positioning post 2502. The support block 2511 is slidably connected inside the support groove 2512. By sliding the support block 2511 inside the support groove 2512, the docking position between the positioning post 2502 and the support rod 2510 can be stabilized. Thus, the support rod 2510 plays a role in stabilizing the position of the positioning post 2502 and preventing the positioning post 2502 from shifting or rotating, which would affect normal use.

[0026] One end of the pusher 2505 is fixedly connected to a limiting rod 2513, and one end of the limiting rod 2513 passes through the guide rail 22 and is slidably connected to the inner cavity of the guide rail 22. A limiting block 2514 is fixedly installed on one end of the limiting rod 2513. A limiting groove 2515 is opened inside the guide rail 22, and the limiting block 2514 is slidably connected inside the limiting groove 2515. By sliding the limiting block 2514 inside the limiting groove 2515, the position of the limiting rod 2513 can be stabilized by the limiting block 2514, and then the position of the pusher 2505 can be stabilized by the limiting rod 2513, so as to avoid the displacement of the positioning column 2502 caused by the positional deviation of the pusher 2505.

[0027] The transmission assembly 24 includes a fixed frame 2401, which is fixedly installed on one side of the frame 1. A hydraulic cylinder 2402 is fixedly installed inside the fixed frame 2401. A transmission shaft 2403 is fixedly connected to the telescopic end of the hydraulic cylinder 2402. A connecting frame 2404 and a bearing seat 2405 are fixedly installed on the side of the main spindle box body 11 opposite to the frame 1. One end of the transmission shaft 2403 passes through the bearing seat 2405 and is slidably connected to the inner cavity of the bearing seat 2405. One end of the transmission shaft 2403 is fixedly sleeved inside the connecting frame 2404. The hydraulic cylinder 2402 drives the transmission shaft 2403 to move, and the bearing seat 2405 stabilizes the position of the transmission shaft 2403, so that the transmission shaft 2403 drives the main spindle box body 11 to move through the connecting frame 2404, thereby adjusting the position of the main spindle body 1102.

[0028] The specific implementation of this embodiment is as follows: When it is necessary to adjust the position of the spindle body 1102, the hydraulic cylinder 2402 drives the transmission shaft 2403 to move, and the position of the transmission shaft 2403 is stabilized by the bearing seat 2405, so that the transmission shaft 2403 drives the spindle box body 11 to move through the connecting frame 2404, thereby achieving the function of adjusting the position of the spindle body 1102. After the spindle body 1102 is moved to the required position, the electric push rod 2504 drives the push frame 2505 to move, and... The limiting block 2514 is slidably connected inside the limiting groove 2515. The limiting block 2514 can stabilize the position of the limiting rod 2513, and in turn, the limiting rod 2513 can stabilize the positioning position of the push frame 2505, preventing the push frame 2505 from shifting position. This allows the push frame 2505 to move inside the opening 2506 and contact the roller 2509. The push frame 2505 then pushes the top block 2507 through the roller 2509 and the crossbar 2508, causing the top block 2507 to move. The positioning post 2502 moves and is slidably connected to the inside of the support groove 2512 via the support block 2511. The support block 2511 stabilizes the docking position of the positioning post 2502 and the support rod 2510, thereby allowing the support rod 2510 to stabilize the position of the positioning post 2502 and prevent the positioning post 2502 from shifting or rotating. One end of the positioning post 2502 can be inserted into the inside of the positioning groove 2503, thereby positioning the guide block 21 through the positioning component 25, further stabilizing the position. The position of the main spindle box body 11 is fixed, thereby effectively stabilizing the position of the main spindle body 1102. When the position of the main spindle body 1102 needs to be readjusted, the electric push rod 2504 drives the push frame 2505 to reset. After the push frame 2505 separates from the roller 2509, the inclined surface of the push frame 2505 can drive the positioning pin 2502 to reset into the cavity 2501, thereby separating the positioning pin 2502 from the positioning groove 2503, so as to carry out the readjustment of the position of the main spindle body 1102.

[0029] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0030] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-rigidity horizontal spindle structure with a spindle box, comprising a frame (1) and a spindle box body (11), characterized in that: The frame (1) is provided with a sliding mechanism (2), which is used in conjunction with the spindle box body (11). The spindle box body (11) is fixedly sleeved inside, and the spindle body (1102) is connected to the spindle body inside the spindle sleeve (1101). The sliding mechanism (2) includes a guide block (21), which is fixedly installed on the side of the spindle box body (11) opposite to the frame (1). A guide rail (22) is fixedly installed inside the frame (1). The guide block (21) is slidably sleeved inside the guide rail (22). A Z-axis positioning block (23) is fixedly installed inside the frame (1). The Z-axis positioning block (23) works in conjunction with the guide rail (22). A positioning component (25) is provided inside the guide rail (22). The positioning component (25) works in conjunction with the guide block (21). A transmission component (24) is provided on one side of the frame (1). The transmission component (24) works in conjunction with the spindle body (1102).

2. The high-rigidity horizontally mounted box-type spindle structure according to claim 1, characterized in that: A lead screw interface (101) is provided on one side of the frame (1), a grating ruler mounting surface (102) is fixedly installed on the inner wall of the frame (1), a Y-axis positioning block (103) is fixedly installed on one side of the frame (1), a limit boss (104) is fixedly installed on both sides of the bottom of the frame (1), a distributor mounting surface (105) is fixedly installed on the bottom of the frame (1), and a secondary bracket mounting surface (106) is fixedly installed on both sides of the frame (1).

3. The high-rigidity horizontally mounted box-type spindle structure according to claim 1, characterized in that: The surface of the guide block (21) is provided with a pressure groove (2202), and the inner wall of the guide rail (22) is fixedly installed with a pressure strip (2201). The surface of the pressure strip (2201) is slidably connected to the inner cavity of the pressure groove (2202).

4. The high-rigidity horizontally mounted box-type spindle structure according to claim 1, characterized in that: The positioning component (25) includes a cavity (2501) located inside the guide rail (22). A positioning post (2502) is slidably fitted inside the cavity (2501). One end of the positioning post (2502) passes through the guide rail (22) and is slidably connected to the inner cavity of the guide rail (22). A plurality of positioning grooves (2503) are provided on the side of the guide block (21) opposite to the guide rail (22). The positioning post (2502) and the positioning grooves (2503) cooperate in use. An electric push rod (2504) is fixedly installed inside the cavity (2501). The telescopic end of the electric push rod (2504) is fixedly connected to a push frame (2505). An opening (2506) is provided on one side of the positioning column (2502). One end of the push frame (2505) passes through the opening (2506) and is slidably connected to the inner cavity of the opening (2506). A top block (2507) is fixedly installed inside the opening (2506). The push frame (2505) and the top block (2507) are used in conjunction.

5. A high-rigidity horizontally mounted box-type spindle structure according to claim 4, characterized in that: A crossbar (2508) is fixedly installed inside the top block (2507), and a roller (2509) is rotatably sleeved on the surface of the crossbar (2508). The roller (2509) is used in conjunction with the pusher (2505).

6. The high-rigidity horizontally mounted box-type spindle structure according to claim 4, characterized in that: A support rod (2510) is fixedly connected inside the cavity (2501). One end of the support rod (2510) passes through the positioning post (2502) and is slidably connected to the inner cavity of the positioning post (2502).

7. A high-rigidity horizontally mounted box-type spindle structure according to claim 6, characterized in that: One end of the support rod (2510) is fixedly installed with a support block (2511), and the positioning column (2502) has a support groove (2512) inside, and the support block (2511) is slidably connected inside the support groove (2512).

8. A high-rigidity horizontally mounted box-type spindle structure according to claim 4, characterized in that: One end of the pusher (2505) is fixedly connected to a limiting rod (2513), and one end of the limiting rod (2513) passes through the guide rail (22) and is slidably connected to the inner cavity of the guide rail (22).

9. A high-rigidity horizontally mounted box-type spindle structure according to claim 8, characterized in that: One end of the limiting rod (2513) is fixedly installed with a limiting block (2514), and a limiting groove (2515) is opened inside the guide rail (22). The limiting block (2514) is slidably connected inside the limiting groove (2515).

10. A high-rigidity horizontally mounted box-type spindle structure according to claim 1, characterized in that: The transmission assembly (24) includes a fixed frame (2401), which is fixedly installed on one side of the frame (1). A hydraulic cylinder (2402) is fixedly installed inside the fixed frame (2401). A transmission shaft (2403) is fixedly connected to the telescopic end of the hydraulic cylinder (2402). A connecting frame (2404) and a bearing seat (2405) are fixedly installed on the side of the main shaft box body (11) opposite to the frame (1). One end of the transmission shaft (2403) passes through the bearing seat (2405) and is slidably connected to the inner cavity of the bearing seat (2405). One end of the transmission shaft (2403) is fixedly sleeved inside the connecting frame (2404).

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