Central water outlet main shaft

Abstract

The utility model relates to the technical field of machining, and discloses a center water outlet main shaft which comprises a machine body. The shaft core is arranged in an inner cavity of the machine body; the vibrator assembly is arranged at the end part of the shaft core and comprises a transducer module and a vibrator, the transducer module is arranged on the peripheral surface of the vibrator, and a cutter handle is arranged in an inner cavity of the vibrator; the broach assembly is arranged in an inner cavity of the shaft core and used for connecting and positioning the cutter handle; and the central water outlet mechanism is used for introducing a cooling medium, and the cooling medium sequentially passes through the shaft core and the inner cavity of the cutter handle, cools the cutter at the end part of the cutter handle and then acts on a workpiece to be machined. Cooling media are introduced through the center water outlet mechanism, center water outlet is achieved to cool the cutter, the service life of the cutter is prolonged, and the working reliability of the main shaft is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical processing, and more specifically, particularly relates to a central water outlet main shaft. Background Art

[0002] At present, in the cutting processing industry, the requirements for high precision, high gloss and high efficiency of products require the high speed and high precision of machining equipment, especially the spindle, and also put forward higher requirements for spindle tools, such as good wear resistance and long life. With the gradual improvement of the degree of mechanical automation, machining equipment now tends to be high-power, high-speed internal cooling processing equipment to improve the processing efficiency and quality in drilling, milling, grinding and other processes.

[0003] Traditional CNC machining equipment is generally not equipped with a central water cooling device. In order to ensure the high precision, high gloss and high efficiency of the product, a high-precision CNC machine tool spindle with internal cooling is required. Existing internal cooling spindles are generally equipped with a center hole and a water outlet structure is added at the tail end of the rotor. The coolant enters the inner cavity of the tool holder after passing through the center hole. The rear end of the traditional direct-connected spindle requires an external motor drive device, and it is impossible to add a water outlet structure from the tail end of the rotor, so internal cooling cannot be achieved. Summary of the invention

[0004] The utility model aims to provide a central water outlet spindle to address the technical problems existing in the prior art. A cooling medium is introduced through the central water outlet mechanism. The cooling medium passes through the shaft core and the tool handle in sequence to cool the tool at the end of the tool handle, thereby ensuring the reliability of the spindle operation.

[0005] In order to solve the above problems, the technical solution adopted by the utility model is:

[0006] The utility model provides a central water outlet main shaft, comprising:

[0007] Body;

[0008] The shaft core is arranged in the inner cavity of the machine body;

[0009] The vibrator assembly is arranged at the end of the shaft core, and comprises a transducer module and a vibrator, wherein the transducer module is arranged on the outer peripheral surface of the vibrator, and the tool handle is arranged in the inner cavity of the vibrator;

[0010] The broach assembly is arranged in the inner cavity of the shaft core and is used for connecting and positioning the tool handle;

[0011] The central water outlet mechanism is used to introduce cooling medium, which passes through the shaft core and the inner cavity of the tool handle in sequence, cools the tool at the end of the tool handle, and then acts on the workpiece to be processed.

[0012] Furthermore, the central water outlet mechanism includes an air bearing and a bearing sleeve arranged on the outer peripheral surface of the air bearing, and the air bearing is arranged on the outer periphery of the shaft core; corresponding liquid inlet holes and liquid inlet passages are arranged on the air bearing and the bearing sleeve for connecting the liquid inlet to allow the cooling medium to enter.

[0013] Furthermore, the central water outlet mechanism also includes a plurality of medium flow channels, a medium channel connected to the liquid inlet hole is arranged on the shaft core, an axial channel and a radial channel connected are arranged on the vibrator, the radial channel is connected to the medium channel, and the axial channel is connected to the inner cavity of the tool handle.

[0014] Furthermore, the air-floating bearing is provided with an air-floating hole and an air-floating channel which are connected to each other. The air-floating channel is connected to the air inlet and allows sealing gas to pass through. A small-hole throttle is provided in the air-floating hole.

[0015] Furthermore, the air bearing is provided with an overflow hole and an overflow channel which are connected to each other. The overflow hole is connected to the medium channel, and the overflow channel is connected to the liquid outlet.

[0016] Furthermore, the air bearing is also provided with an overflow groove connecting the overflow hole and the overflow channel; the bearing sleeve is also provided with an air flotation passage connecting the air inlet and the air flotation hole, and an overflow circuit connecting the overflow hole and the liquid outlet.

[0017] Furthermore, the broach assembly includes a pull rod and a pull rivet arranged in the shaft core, the pull rivet is arranged at the end of the pull rod and connected to the tool handle; the pull rod is provided with a radial through hole, the pull rivet is provided with a central through hole, and the central through hole is respectively connected to the radial through hole and the inner cavity of the tool handle.

[0018] Furthermore, a one-way valve is provided in the inner cavity of the other end of the pull rod opposite to the pull nail.

[0019] Furthermore, an energy transmission component is arranged in the body and located on the periphery of the shaft core, and the energy transmission component includes a wireless power supply module and a wireless power receiving module that are relative and clearance-matched, the wireless power supply module is connected to an external ultrasonic power source, and the wireless power receiving module is connected to the transducer module.

[0020] Furthermore, a wire outlet hole and a wire burying hole are respectively provided on the shaft core, the wire outlet hole is used to pass the wire connecting the wireless power receiving module and the transducer module, and the wire burying hole is used to store the wire; the wire segment between the wire outlet hole and the wire burying hole is pressed by the outer edge of the fixing part on the shaft core.

[0021] Compared with the prior art, the beneficial effects of the utility model are:

[0022] 1. In the utility model, a cooling medium is introduced by setting a central water outlet mechanism. After the cooling medium passes through the shaft core and the inner cavity of the tool holder in turn, the tool is cooled, thereby increasing the service life of the tool. The transducer module is used to make the spindle perform ultrasonic vibration. When the cooling medium acts on the workpiece to be processed, the chips on the surface of the workpiece can be taken away, and under the action of ultrasonic vibration, a cavitation effect can also be generated on the surface of the workpiece, thereby improving the processing quality and chip removal efficiency of the workpiece surface and ensuring the processing efficiency.

[0023] 2. The central water outlet mechanism of the utility model adopts an air bearing and a bearing jacket, and is provided with corresponding liquid inlet holes and liquid inlet passages for connecting the liquid inlet to allow the cooling medium to enter, thereby cooling the tool and ensuring the sealing of the spindle and the reliability of the work.

[0024] 3. The air bearing of the utility model realizes air sealing by providing a liquid inlet hole to allow the cooling medium to pass through, providing an air flotation hole and an air flotation channel to allow the sealing gas to pass through, and providing an overflow hole and an overflow channel to allow the cooling medium to reflux, that is, the air bearing adopts a two-way sealing structure of an overflow hole and an air flotation hole, which ensures the sealing reliability of the water outlet and further ensures the reliability of the main shaft operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the scheme of the utility model, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0026] Figure 1 It is the overall structure diagram of the central water outlet main shaft of the utility model.

[0027] Figure 2 This is another structural diagram of the central water outlet main shaft of the utility model.

[0028] Figure 3 It is a schematic diagram of the air flotation circuit of the central water outlet main shaft of the utility model.

[0029] Figure 4 It is a schematic diagram of the overflow circuit of the central water outlet main shaft of the utility model.

[0030] Figure 5 A is a partial enlarged schematic diagram of the central water outlet main shaft of the utility model.

[0031] Figure 6 It is a structural diagram of the air floating bearing in the utility model.

[0032] Figure 7 It is the front view of the air bearing in the utility model.

[0033] Figure 8 It is a schematic diagram of the center line head protection of the utility model.

[0034] Among them, 1-body, 2-axis core, 3-wireless power supply module, 4-wireless power receiving module, 5-front bearing group, 6-rear bearing group, 7-transducer module, 8-air bearing, 9-vibrator, 10-gear plate, 11-tool handle, 12-bearing sleeve, 13-broach assembly, 14-small hole throttle, 15-check valve, 16-preload spring, 17-wire, 21-medium channel, 91-axial channel, 92-radial channel, 81-liquid inlet, 82-air Floating hole, 82a-first air floating hole, 82b-second air floating hole, 82c-third air floating hole, 83-overflow hole, 83a-upper overflow hole 83a, 83b-lower overflow hole, 84-air floating channel, 85-overflow channel, 86-overflow groove, 121-liquid inlet passage, 122-air floating passage, 123-overflow circuit, 131-pull rod, 132-pull nail, 1311-radial through hole, 201-wire outlet hole, 202-wire embedding hole, 203-fixing part. DETAILED DESCRIPTION

[0035] Unless otherwise defined, all technical and scientific terms used in this document have the same meaning as commonly understood by technicians in the technical field of the present invention; the terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. For example, the directions or positions indicated by terms such as "length", "width", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", and "outside" are based on the directions or positions shown in the drawings, which are only for the convenience of description and cannot be understood as limitations on the present technical solution.

[0036] The terms "including" and "having" and any variations thereof in the specification and claims of the utility model and the above-mentioned drawings are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the utility model or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In the specification and claims of the utility model and the above-mentioned drawings, when an element is referred to as "fixed to" or "mounted on" or "disposed on" or "connected to" another element, it may be directly or indirectly located on the other element. For example, when an element is referred to as "connected to" another element, it may be directly or indirectly connected to the other element.

[0037] In addition, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0038] See also Figure 1 to Figure 6 As shown, the utility model provides a central water outlet main shaft, comprising:

[0039] Body 1;

[0040] The shaft core 2 is disposed in the inner cavity of the body 1 and is capable of rotating relative to the body 1;

[0041] A vibrator assembly is arranged at the end of the shaft core 2, and comprises a transducer module 7 and a vibrator 9. The transducer module 7 is arranged on the outer peripheral surface of the vibrator 9, and the inner cavity of the vibrator 9 is arranged with a tool handle 11;

[0042] The broaching tool assembly 13 is arranged in the inner cavity of the shaft core 2 and is used to connect and position the tool handle 11, that is, to realize the broaching and loosening control of the tool handle 11 when the tool handle 11 is replaced;

[0043] The central water outlet mechanism is arranged on the periphery of the shaft core 2 and corresponds to the position of the transducer assembly, and is used to pass the cooling medium. The cooling medium passes through the shaft core 2, the vibrator 9 and the inner cavity of the tool handle 11 in sequence, and after cooling the tool at the end of the tool handle 11, it acts on the workpiece to be processed.

[0044] In this embodiment, the energy transmission component is connected via the vibrator component to enable the spindle to achieve ultrasonic vibration processing, thereby improving the processing quality of the product surface, extending the service life of the tool, and meeting high-precision processing requirements; by setting a central water outlet mechanism to introduce cooling medium, the heated transducer module 7 and the tool handle 11 can be cooled, thereby ensuring the reliability of the spindle operation and improving the processing accuracy of the product surface.

[0045] Furthermore, the central water outlet mechanism includes an air bearing 8 and a bearing sleeve 12. The air bearing 8 is arranged on the periphery of the end of the shaft core 2 and corresponds to the position of the transducer module 7; the bearing sleeve 12 is arranged on the outer peripheral surface of the air bearing 8, and is used to protect and position the air bearing 8; the air bearing 8 and the bearing sleeve 12 are provided with corresponding liquid inlet holes 81 and liquid inlet passages 121, which are used to connect the liquid inlet to allow the cooling medium to pass through.

[0046] Furthermore, the central water outlet mechanism also includes a plurality of medium flow channels. A medium channel 21 connected to the liquid inlet hole 81 is provided on the shaft core 2. An axial channel 91 and a radial channel 92 connected to each other are provided on the vibrator 9. The radial channel 92 is connected to the medium channel 21. The axial channel 91 corresponds to the position of the transducer module 7 and is connected to the inner cavity of the tool handle 11, so as to facilitate the flow of cooling medium in the corresponding channel, thereby cooling the transducer module 7 and the tool handle 11.

[0047] In other embodiments of the utility model, the air bearing 8 and the bearing sleeve 12 can also be arranged at the middle and rear end of the shaft core 2. Taking the air bearing 8 and the bearing sleeve 12 both being located at the rear end of the shaft core 2 as an example, the air bearing 8 is arranged on the outer peripheral surface of the shaft core 2 and is located on one side of the rear end cover. The shaft core 2 is provided with a relatively long medium hole along the axial direction. The medium hole is connected to the liquid inlet hole 81 of the air bearing 8 and the inner cavity of the tool handle 11 respectively, and the cooling medium can also be introduced and the cooling medium can cool the tool through the inner cavity of the tool handle. Compared with the present embodiment, the air bearing 8 is arranged at the front end of the shaft core 2 and corresponds to the position of the transducer module 7, so that a relatively long medium hole can be avoided on the shaft core 2, and the structural rigidity of the shaft core 2 can be improved. At the same time, the movement stroke of the cooling medium can be shortened, and the working efficiency of the mechanism can be improved.

[0048] Furthermore, the air bearing 8 is provided with an air flotation hole 82 and an air flotation channel 84 which are connected to each other. The air flotation channel 84 is connected to the air inlet and allows the sealing gas to be introduced to air-seal the spindle. A small hole throttle 14 is provided in the air flotation hole 82 of the air bearing 8 to adjust the pressure of the sealing gas introduced to ensure the reliability of the air sealing of the spindle.

[0049] Specifically, in order to ensure the reliability of the overall airtightness of the main shaft, three groups of air flotation holes 82 are arranged in the axial direction on the air flotation bearing 8, namely, the first air flotation hole 82a, the second air flotation hole 82b, and the third air flotation hole 82c ( Figure 3 As shown in FIG. 1 , the liquid inlet hole 81 is located between two groups of the air flotation holes 82. Each group of air flotation holes 82 is provided with a plurality of holes along the circumference of the air flotation bearing 8. A small hole throttle 14 ( Figure 5 ), that is, the sealing gas pressure can be adjusted separately.

[0050] Furthermore, the air bearing 8 is also provided with an overflow hole 83 and an overflow channel 85 which are connected to each other. The overflow hole 83 is connected to the medium channel 21, and the overflow channel 85 is connected to the liquid outlet. The excess cooling medium in the medium channel 21 flows back and is discharged after passing through the overflow hole 83 and the overflow channel 85, thereby further ensuring the sealing of the main shaft.

[0051] Specifically, the liquid inlet hole 81, the air flotation hole 82, and the overflow hole 83 are sequentially arranged along the radial direction of the air flotation bearing 8, and are connected to the inner cavity of the air flotation bearing 8. The overflow hole 83 is provided in two groups, namely, an upper overflow hole 83a and a lower overflow hole 83b, and is respectively arranged on both sides of the liquid inlet hole 81. The overflow hole 83 is located between the liquid inlet hole 81 and the air flotation hole 82, that is, the upper overflow hole 83a is located between the liquid inlet hole 81 and the first air flotation hole 82a, and the lower overflow hole 83b is located between the liquid inlet hole 81 and the second air flotation hole 82b ( Figure 5 and Figure 6 ), which can ensure the reliability of the spindle operation.

[0052] In this embodiment, the number of the air flotation holes 82 and the overflow holes 83 can be increased or decreased according to actual needs, and the positional relationship among the liquid inlet hole 81, the air flotation hole 82 and the overflow hole 83 can also be adjusted according to actual needs, all of which can meet the needs of the spindle operation.

[0053] Furthermore, an overflow groove 86 is also provided on the air bearing 8. The overflow groove 86 is arranged along the circumference of the air bearing 8 and is respectively connected to the overflow hole 83 and the overflow channel 85. That is, the excess cooling medium in the overflow hole 83 is first stored in the overflow groove 86 and then discharged through the overflow channel 85, thereby ensuring the reliability of the operation.

[0054] Furthermore, the bearing sleeve 12 is also provided with an air flotation passage 122 and an overflow circuit 123 along the radial direction, the air flotation passage 122 connects the air inlet and the air flotation hole 82, and the overflow circuit 123 connects the overflow hole 83 and the liquid outlet, so that the sealing gas can flow in smoothly and the cooling medium can flow back and be discharged smoothly. Specifically, in order to facilitate the reliable entry and reflux discharge of the cooling medium and to facilitate the entry of the sealing gas, the bearing sleeve 12 is provided with joints at the liquid inlet, liquid outlet and air inlet.

[0055] Furthermore, the broach assembly 13 includes a draw rod 131 and a draw nail 132. The draw rod 131 is arranged in the shaft core 2; the draw nail 132 is arranged at the end of the draw rod 131 and is connected and matched with the handle 11; the draw rod 131 is provided with a radial through hole 1311 ( Figure 1 As shown in ), the rivet 132 is provided with a central through hole, and the central through hole is communicated with the radial through hole 1311 and the inner cavity of the shank 11 respectively, and the radial through hole 1311 is connected with the axial channel 91 and the central through hole.

[0056] Specifically, according to the size of the knife handle 11, the pull rod 131 and the pull nail 132 can be connected by ball fitting ( Figure 1 , Figure 2As shown in FIG. 1 , the tool handles 11 of different sizes can also be reliably positioned by means of the claws, which is convenient for tool change operations. The axial channel 91 and the central through hole are connected through the radial through hole 1311, and the cooling medium is introduced into the inner cavity of the tool handle 11, which is convenient for processing and implementation, and can also avoid processing the medium flow channel on the surface of the tool handle 11, which affects the integrity and precision of the surface of the tool handle 11.

[0057] Furthermore, a one-way valve 15 is provided on the other end of the pull rod 131 opposite to the pull pin 132. The one-way valve 15 is connected to the central through hole of the pull pin 132. When the cooling medium in the radial through hole 1311 enters the central through hole of the pull pin 132, it can prevent part of the cooling medium from reversely entering the end of the main shaft along the central hole of the pull rod 131, thereby affecting the operation of the motor drive device at the rear end of the main shaft.

[0058] In this embodiment, in order to ensure the reliability of the operation of the central water outlet mechanism, seals are provided on the mating surfaces of the vibrator 9 with the shaft core 2 and the pull rod 131, and on the mating surfaces of the pull pin 132 with the pull rod 131 and the tool handle 11 for sealing, so as to avoid leakage when the cooling medium flows in sequence and affect the operation of other parts of the main shaft.

[0059] Furthermore, an energy transmission component is arranged inside the body 1 and on the periphery of the shaft core 2, and the energy transmission component includes a wireless power supply module 3 and a wireless power receiving module 4 that are relative and clearance-matched, the wireless power supply module 3 is connected to an external ultrasonic power supply (not shown in the figure), and the wireless power receiving module 4 is connected to the transducer module 7 to perform wireless power transmission to realize ultrasonic machining.

[0060] Specifically, according to the installation space in the body 1 and different processing requirements, the wireless power supply module 3 and the wireless power receiving module 4 can be arranged along the axial direction or radial direction of the shaft core 2, and the gap between the wireless power supply module 3 and the wireless power receiving module 4 can be adjusted to meet the needs of different power sizes.

[0061] Specifically, a front bearing group 5 and a rear bearing group 6 are relatively arranged in the body 1 and on the outer peripheral surface of the shaft core 2. The front bearing group 5 and the rear bearing group 6 are located on both sides of the energy transmission module, and can provide radial support for rotating components such as the shaft core 2 to ensure that the front / rear bearing groups have sufficient load-bearing capacity and rigidity; a preload spring 16 acting on the front bearing group 5 and / or the rear bearing group 6 is also arranged in the body 1, which can axially preload the front bearing group 5 and the rear bearing group 6 to ensure their rigidity and thus ensure working reliability.

[0062] For further information, see Figure 7As shown, the shaft core 2 is provided with a wire outlet hole 201 and a wire embedding hole 202, respectively. After the wire 17 connecting the wireless power receiving module 4 and the transducer module 7 passes through the wire outlet hole 201, it is stored in the wire embedding hole 202 and fixed by glue filling to prevent the wire ends from accumulating in the cavity of the shaft core 2 where the vibrator 9 is located. It can also prevent the wire 17 from being broken due to the long-term centrifugal force when the shaft core 2 rotates at high speed, thereby affecting the wireless power transmission and further affecting the reliability of the spindle. In order to further ensure that the wire 17 is installed firmly, the wire segment between the wire outlet hole 201 and the wire embedding hole 202 is compressed by a fixing member 203 (such as the outer edge of a nut) on the shaft core 2.

[0063] Specifically, a gear plate 10 is disposed on the outer periphery of the vibrator 9 to facilitate replacement of the tool handle 11 .

[0064] In this embodiment, the sealing of the whole structure needs to be ensured when the main shaft is discharged from the center and overflowed, that is, the sealing gas is introduced into the air flotation passage 122, and the sealing gas passes through the air flotation holes 82 respectively, so that the air flotation bearing 8 and the shaft core 2, the body 1, and the shaft core 2 and the vibrator 9, the body 2 are respectively sealed, thereby ensuring the sealing of the whole structure. Figure 2 as shown in .

[0065] Figure 1 As shown in the central water outlet line, the cooling medium (including cooling oil, cooling water or coolant) enters the liquid inlet passage 121 of the bearing sleeve 12 from the liquid inlet, and passes through the liquid inlet hole 81 of the air bearing 8, the medium channel 21 of the shaft core 2, the radial channel 92 and the axial channel 91 of the vibrator 9, and the radial through hole 1311 of the pull rod 131 in turn, and then enters the center hole of the pull pin 132 and the center of the tool handle 11, and cools the tool at the end of the tool handle 11. The cooling medium discharge also acts on the workpiece to be processed; and the excess cooling medium passes through the overflow hole 83, the overflow groove 86, and the overflow channel 85 in turn, and is discharged from the liquid outlet by the overflow circuit 123.

[0066] By setting the radial through hole 1311 on the pull rod 131, the cooling medium enters the central through hole of the pull pin 132 through the radial through hole 1311, that is, the central water discharge is realized to cool the tool, which increases the service life of the tool, protects the integrity and precision of the surface of the handle 11, facilitates processing and can match handles 1 of different specifications. The cooling medium acts on the surface of the workpiece to be processed, can take away the chips on the surface of the workpiece, and can also produce a cavitation effect on the surface of the workpiece under the action of ultrasonic vibration, thereby improving the processing performance and processing quality of the workpiece surface.

[0067] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A central water outlet spindle, Features: include: Body; The shaft core is arranged in the inner cavity of the machine body; A vibrator assembly is arranged at the end of the shaft core, and comprises a transducer module and a vibrator, wherein the transducer module is arranged on the outer peripheral surface of the vibrator, and the tool handle is arranged in the inner cavity of the vibrator; The broach assembly is arranged in the inner cavity of the shaft core and is used for connecting and positioning the tool handle; The central water outlet mechanism is used to introduce cooling medium, which passes through the shaft core and the inner cavity of the tool handle in sequence, cools the tool at the end of the tool handle, and then acts on the workpiece to be processed.

2. The central water outlet main shaft according to claim 1, Features: The central water outlet mechanism includes an air bearing and a bearing sleeve arranged on the outer peripheral surface of the air bearing, and the air bearing is arranged on the outer periphery of the shaft core; corresponding liquid inlet holes and liquid inlet passages are arranged on the air bearing and the bearing sleeve for connecting the liquid inlet to allow the cooling medium to pass through.

3. The central water outlet main shaft according to claim 2, Features: The central water outlet mechanism also includes a plurality of medium flow channels. A medium channel connected to the liquid inlet hole is arranged on the shaft core. An axial channel and a radial channel connected to each other are arranged on the vibrator. The radial channel is connected to the medium channel, and the axial channel is connected to the inner cavity of the tool handle.

4. The central water outlet main shaft according to claim 2, Features: The air-floating bearing is also provided with an air-floating hole and an air-floating channel which are connected to each other. The air-floating channel is connected to the air inlet and allows sealing gas to flow in. A small-hole throttle is provided in the air-floating hole.

5. The central water outlet main shaft according to claim 3, Features: The air bearing is also provided with an overflow hole and an overflow channel which are connected to each other. The overflow hole is connected to the medium channel, and the overflow channel is connected to the liquid outlet.

6. The central water outlet main shaft according to claim 5, Features: The air bearing is also provided with an overflow groove connecting the overflow hole and the overflow channel; the bearing sleeve is also provided with an air flotation passage connecting the air inlet and the air flotation hole, and an overflow circuit connecting the overflow hole and the liquid outlet.

7. The central water outlet main shaft according to claim 2 or 6, Features: The broach assembly includes a pull rod and a pull rivet arranged in the shaft core, the pull rivet is arranged at the end of the pull rod and connected to the tool handle; the pull rod is provided with a radial through hole, and the pull rivet is provided with a central through hole, and the central through hole is respectively connected to the radial through hole and the inner cavity of the tool handle.

8. The central water outlet main shaft according to claim 7, Features: A one-way valve is arranged in the inner cavity of the other end of the pull rod opposite to the pull nail.

9. The central water outlet main shaft according to claim 1, Features: An energy transmission component is arranged in the body and on the periphery of the shaft core. The energy transmission component comprises a wireless power supply module and a wireless power receiving module which are opposite to each other and have clearance fit. The wireless power supply module is connected to an external ultrasonic power source, and the wireless power receiving module is connected to the transducer module.

10. The central water outlet main shaft according to claim 9, Features: A wire outlet hole and a wire embedding hole are respectively arranged on the shaft core. The wire outlet hole is used to pass the wire connecting the wireless power receiving module and the transducer module, and the wire embedding hole is used to store the wire. The wire segment between the wire outlet hole and the wire embedding hole is pressed tightly by the outer edge of the fixing part on the shaft core.

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