CN212239205U

CN212239205U - High-speed air engraving and milling spindle

Info

Publication number: CN212239205U
Application number: CN202020878520.3U
Authority: CN
Inventors: 周清明
Original assignee: Shenzhen Prosperity Tech Co ltd
Current assignee: SICHUAN XINGWANGDA PRECISION ELECTROMECHANICAL Co.,Ltd.
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2020-12-29
Anticipated expiration: 2030-05-22

Abstract

The utility model provides a high-speed air carving mills main shaft, which comprises a body, the cylinder block subassembly of setting in body one end, bear the cylinder block subassembly on the cylinder block subassembly, the setting is at this internal rotor subassembly, the rotor subassembly includes axle core and cover and establishes the air supporting bearing on the axle core, the terminal surface that the cylinder block subassembly was kept away from to the axle core is provided with footstep bearing, the cylinder block subassembly includes the cylinder block and sets up the air inlet joint on the cylinder block, air supporting bearing's tip is provided with the flange, the flange is close to footstep bearing, first orifice has been seted up on the terminal surface of flange, the second orifice has been seted up on the footstep bearing, the air current channel has been seted up to this internal, the air current flows to first orifice respectively from air current channel, discharge behind. The utility model provides a high-speed air carving mills main shaft is when can realizing finishing impression, highlight requirement, and difficult emergence card is dead, can reach higher rotational speed rapidly.

Description

High-speed air engraving and milling spindle

Technical Field

The utility model belongs to the technical field of the main shaft processing, more specifically say, relate to a high-speed air carving mills main shaft.

Background

Due to the development of digital technologies such as mobile phones, people have higher and higher requirements on production efficiency, and meanwhile, the processing quality is also improved, and the requirements on the appearance smoothness of products such as mobile phone shells are higher and higher, so that the requirements on precision engraving and highlight motors are higher, the requirements on the rotating speed are higher, the running stability of the motors is good, the swinging of the motors at high speed is small, and the like.

The existing main shaft has the requirement of realizing fine carving and highlight, but the rotating speed of the main shaft cannot meet the requirement rapidly, while the existing main shaft can reach a higher rotating speed rapidly, the phenomenon of main shaft locking is easy to occur, and the effects of fine carving and highlight are not ideal.

Therefore, a main shaft capable of rapidly achieving a high rotation speed while achieving a precise engraving and a high light requirement is required.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a high-speed air carving mills main shaft to solve the problem that the high-speed air carving that exists mills the main shaft among the prior art.

In order to achieve the above object, the utility model adopts the following technical scheme: provides a high-speed air engraving and milling main shaft, which comprises a body, a cylinder block component arranged at one end of the body, a cylinder component bearing the cylinder block component, and a rotor component arranged in the body, the rotor component comprises a shaft core and an air bearing sleeved on the shaft core, the end surface of the shaft core is provided with a thrust bearing, the end surface of the shaft core is provided with a thrust bearing, the cylinder block component comprises a cylinder block and an air inlet joint arranged on the cylinder block, a flange is arranged at the end part of the air bearing, a first throttling hole is arranged on the end surface of the flange, the thrust bearing is provided with a second throttling hole, the body is internally provided with an airflow channel, airflow flows to the first throttling hole and the second throttling hole from the airflow channel and then is discharged, and the airflow separates the air bearing from the shaft core.

Furthermore, an air inlet is formed in the circumferential surface of the air bearing and communicated with the first throttling hole.

Furthermore, two circles of the first throttle holes are formed in the end face of the flange, the number of the first throttle holes in each circle is equal, and the number of the first throttle holes is thirty-six.

Furthermore, two circles of the second throttle holes are formed in the end face of the thrust bearing, the number of the second throttle holes in each circle is equal, and the number of the second throttle holes is thirty-six.

Furthermore, one surface of the thrust bearing, which faces the shaft core, is provided with two circles of air grooves, the two circles of second throttling holes are arranged in the two circles of air grooves, and the air grooves are communicated with the air flow channel.

Furthermore, a water inlet joint and a water outlet joint are further arranged on the cylinder seat, an inner sleeve is arranged between the body and the shaft core, a spiral groove is formed in the circumferential surface of the inner sleeve, a cooling water path is formed between the spiral groove and the inner sleeve, two ends of the cooling water path are respectively communicated with the water inlet joint and the water outlet joint, and cooling liquid sequentially flows through the water inlet joint, the cooling water path and the water outlet joint.

Further, the cylinder assembly comprises a rear cover, a shell, a plurality of push sheets and a plurality of spacers, wherein the shell is arranged on the cylinder seat, the rear cover is arranged on the shell, and the push sheets and the spacers are arranged in the shell and the rear cover; and a sealing ring is connected between the shell and the push sheet.

Furthermore, a return spring is arranged at one end, close to the air cylinder, of the air cylinder seat, an ejector rod is arranged in the shaft core, a chuck is arranged at one end, far away from the air cylinder seat, of the ejector rod, the chuck is connected with a nut, and the nut is located between the ejector rod and the chuck; the reset spring is used for providing reset force for the air cylinder and pushing the push sheet to one end of the rear cover, so that the ejector rod and the nut are separated.

Furthermore, a tool changing air pressure joint is arranged on the rear cover and communicated with the rear cover and the shell; the air current follow tool changing atmospheric pressure connects the flow direction ejector pin and nut, the air current follow avoid the dust to get into behind the nut outflow the axle core.

Furthermore, the thrust bearing and the shaft core are in clearance fit, a front cover is arranged on the end face of the thrust bearing, and the front cover, the shaft core and the thrust bearing form a labyrinth air path.

The utility model provides a high-speed air carving mills main shaft's beneficial effect lies in: compared with the prior art, the utility model discloses set up air inlet joint on the cylinder block, establish air supporting bearing at the axle center overcoat, the terminal surface of axle center is provided with footstep bearing. Wherein, the cylinder block subassembly includes cylinder block and the air inlet joint of setting on the cylinder block, air bearing's tip integrated into one piece has the flange, first orifice has been seted up on the terminal surface of flange, the second orifice has been seted up on the footstep bearing, set up airflow channel on the body, make the air current follow air inlet joint get into the back through airflow channel, then discharge behind the first orifice of flow direction respectively and the second orifice, the air current makes air bearing and axle core produce the air cushion at the in-process that flows, make air bearing can and the axle core produce the clearance under the effect of air current between, the friction between axle core and the air bearing has greatly been reduced, and the efficiency is improved. The axle core is difficult to with other part contact under the effect of air current for the difficult dead phenomenon of card takes place for the axle core at the pivoted in-process, in addition, because the air current makes the air supporting bearing and the production air cushion between the axle core at the in-process that flows, makes the axle core reduce greatly from zero resistance of accelerating to high rotational speed, and the time that accelerates required also reduces greatly.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments or the prior art descriptions will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive labor.

Fig. 1 is a schematic structural diagram of a high-speed air engraving and milling spindle provided in an embodiment of the present invention, and a part of the structure is not shown;

fig. 2 is a cross-sectional view of the high-speed air engraving and milling spindle provided in the embodiment of the present invention, and a part of the structure is not shown;

fig. 3 is a schematic structural diagram of an air bearing according to an embodiment of the present invention, and a part of the structure is not shown;

fig. 4 is a schematic structural diagram of a thrust bearing provided in an embodiment of the present invention, a part of the structure is not shown;

fig. 5 is a schematic structural diagram of a thrust bearing provided in an embodiment of the present invention, a part of the structure is not shown;

fig. 6 is a schematic structural view of an inner sleeve according to an embodiment of the present invention.

Wherein, in the drawings, the reference numerals are mainly as follows:

1. a body;

2. a cylinder block assembly; 201. a cylinder block; 202. an air inlet joint; 203. a water inlet joint; 204. a water outlet joint;

3. a cylinder assembly; 31. a rear cover; 32. a housing; 33. pushing the sheet; 34. a spacer;

4. a rotor assembly; 41. a shaft core; 42. an inner sleeve;

5. an air bearing; 51. a flange;

6. a thrust bearing; 7. a first orifice; 8. a second orifice; 9. an air tank; 12. a helical groove; 13. a return spring; 14. a top rod; 15. a chuck; 16. a nut; 17. changing a tool pneumatic connector; 18. a shaft heater; 19. a nut sleeve; 20. a mouse cage; 21. and a coil.

Detailed Description

In order to make the technical problem, technical solution and advantageous effects to be solved by the present invention more clearly understood, the following description is given in conjunction with the accompanying drawings and embodiments to illustrate the present invention in further detail. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, fig. 2, fig. 4 and fig. 5, a high-speed air engraving and milling spindle according to an embodiment of the present invention will now be described. The high-speed air engraving and milling main shaft comprises a body 1, a cylinder seat assembly 2, a cylinder assembly 3 and a rotor assembly 4. The body 1 is sleeved outside the rotor assembly 4, the cylinder block assembly 2 is arranged at one end of the body 1 and used for bearing the cylinder assembly 3, and the cylinder block assembly 2 is located between the cylinder assembly 3 and the body 1. The rotor assembly 4 comprises a shaft core 41 and an air bearing 5 sleeved outside the shaft core 41, a thrust bearing 6 is arranged on the end face, away from the cylinder block 201, of the shaft core 41, the cylinder block assembly 2 comprises a cylinder block 201 and an air inlet joint 202, and the air inlet joint 202 is arranged on the cylinder block 201. End integrated into one piece of air bearing 5 has flange 51, first orifice 7 has been seted up to the terminal surface of flange 51, the second orifice 8 has been seted up on the footstep bearing 6, airflow channel (not seen in the figure) has been seted up in the body 1, the main shaft is at the during operation, the outside air gets into airflow channel from air inlet joint 202, then discharge after flowing to first orifice 7 and second orifice 8 respectively, the air current makes air bearing 5 and axle core 41 produce the air cushion at the in-process that flows, make under the effect of air current air bearing 5 can and the axle core 41 between produce the clearance, the friction between axle core 41 and the air bearing 5 has been eliminated, the efficiency is improved. The shaft core 41 is difficult to contact with other components under the action of the air flow, so that the shaft core 41 is not easy to be jammed in the rotating process, and in addition, because the air flow generates an air cushion between the air bearing 5 and the shaft core 41 in the flowing process, the resistance of the shaft core 41 from zero acceleration to high rotation speed is greatly reduced, and the time required by acceleration is also greatly reduced (for example, in the embodiment, the rotation speed of the shaft core 41 needs to be accelerated from zero to sixty thousand rotations in one second).

The utility model provides a high-speed air carving mills main shaft compares with prior art, sets up air inlet joint 202 on cylinder block 201, establishes air supporting bearing 5 at axle core 41 overcoat, and the terminal surface of axle core 41 is provided with footstep bearing 6. Wherein, cylinder block 201 subassembly 2 includes cylinder block 201 and the air inlet joint 202 of setting on cylinder block 201, the tip integrated into one piece of air bearing 5 has flange 51, first orifice 7 has been seted up on the terminal surface of flange 51, the second orifice 8 has been seted up on the footstep bearing 6, set up the air current passageway on body 1, make the air current pass through the air current passageway after the air current gets into from air inlet joint 202, then discharge after flowing to first orifice 7 and second orifice 8 respectively, the air current makes air bearing 5 and axle core 41 produce the air cushion at the in-process that flows, make air bearing 5 can and the axle core 41 produce the clearance under the effect of air current, the friction between axle core 41 and the air bearing 5 has been eliminated, the efficiency is improved. The shaft core 41 is difficult to contact with other components under the action of the airflow, so that the shaft core 41 is not easy to be blocked in the rotating process, and in addition, because the airflow generates an air cushion between the air bearing 5 and the shaft core 41 in the flowing process, the resistance of the shaft core 41 from zero acceleration to high rotation speed is greatly reduced, and the time required by acceleration is also greatly reduced.

Specifically, referring to fig. 2 to 5, an air inlet hole (not shown) is formed on the circumferential surface of the air bearing 5, and the air inlet hole is communicated with the first throttle hole 7. Two circles of the first throttle holes 7 are opened in the end face of the flange 51, the number of the first throttle holes 7 per circle is equal, the number of the first throttle holes 7 per circle is thirty-six, that is, the number of the first throttle holes 7 per circle is eighteen. The end face of the thrust bearing 6 is provided with second orifices 8, the number of the second orifices 8 is the same as that of the first orifices 7, and the number of the second orifices 8 in each circle is the same. It was mentioned above that the air flows from the air intake joint 202 to the air flow passage and then to the first throttle hole 7 and the second throttle hole 8, respectively. Specifically, the airflow is divided into two paths after flowing through the airflow channel, and one path flows to the second throttle hole 8; the other path flows to the air bearing 5, a part of the air flow flows to the second throttle hole 8 after flowing to the outer peripheral surface of the air bearing 5, and a part of the air flow enters the air bearing 5 and is discharged.

In addition, referring to fig. 1, 2 and 6, the cylinder block 201 is further provided with a water inlet joint 203 and a water outlet joint 204, an inner sleeve 42 is disposed between the main body 1 and the bearing, a spiral groove 12 is disposed on the circumferential surface of the inner sleeve 42, a cooling water path is formed between the spiral groove 12 and the inner sleeve 42, two ends of the cooling water path are respectively communicated with the water inlet joint 203 and the water outlet joint 204, and the cooling liquid sequentially flows through the water inlet joint 203, the cooling water path and the water outlet joint 204 to cool the spindle core 41 during the high-speed operation of the spindle.

In detail, referring to fig. 2, the cylinder assembly 3 includes a rear cover 31, a housing 32, a push plate 33, and a spacer 34, the housing 32 is disposed on a cylinder block 201, wherein the housing 32 includes three portions (32 a, 32b, 32 c), and the rear cover 31 is disposed on the housing 32. The number of the spacers 34 and the push pieces 33 is larger than one, the spacers 34 and the push pieces 33 are arranged in the shell 32 or the rear cover 31, and a sealing ring is connected between the shell 32 and the push pieces 33. The sealing ring is an O-shaped ring, the sealing ring has a good sealing effect, and if a proper amount of lubricating oil is smeared on the sealing ring, a lower friction coefficient can be achieved, so that the power loss of the air cylinder during working is greatly reduced.

Further, referring to fig. 2, a return spring 13 is disposed at one end of the cylinder block 201 close to the cylinder, a push rod 14 is disposed in the shaft core 41, a nut 16 and a chuck 15 are disposed at an end of the push rod 14, the nut 16 is disposed between the push rod 14 and the chuck 15, wherein the nut 16 and the chuck 15 are disposed at one end of the push rod 14 away from the cylinder block 201, and the return spring 13 is used to provide an elastic force to the cylinder and push the push plate 33 toward one end of the rear cover 31, so that the push rod 14 is spaced from the nut 16 to prevent the push rod 14 from being stuck due to contact with the nut 16.

Preferably, referring to fig. 1 and fig. 2, a tool changing air pressure joint 17 is further disposed on the rear cover 31, the tool changing air pressure joint 17 is communicated with the rear cover 31 and the housing 32, air flows from the tool changing air pressure joint 17 to the ejector rod 14 and the nut 16, and air flows toward the ejector rod 14 and the nut 16 through the air flow externally connected to the rear cover 31 and jets out the air flow to the front end of the shaft core 41, so that dust cannot enter the spindle during tool changing, the interior of the spindle is in a dust-free state, and the service life of the spindle is greatly prolonged.

Preferably, the thrust bearing 6 and the shaft core 41 are in clearance fit, the end face of the thrust bearing 6 is provided with a front cover, and the front cover, the shaft core 41 and the thrust bearing 6 form a labyrinth air path, so that air coming out of the end face of the thrust bearing 6 forms an air cavity at the chamfer of the bearing flange 51, dust cannot enter the main shaft, and the main shaft is prevented from being locked to shorten the service life.

Referring to fig. 1-6, the following is a detailed description of the present invention:

the spindle mainly comprises a cylinder assembly 3, a cylinder seat assembly 2, an air floatation bearing assembly, a body assembly, a rotor assembly 4 and a thrust bearing assembly.

The cylinder assembly 3 mainly comprises a rear cover 31, a push sheet 33a, a spacer 34a, a shell 32b, a push sheet 33b, a spacer 34b and a push sheet 33c, and a shell 32 c. The rear cover 31 is provided with a tool changing air pressure joint 17, when the spindle needs tool changing, air with certain air pressure is injected into the air cylinder through the tool changing air pressure joint 17, force is transmitted to the push sheet 33 through the push sheet 33 and then transmitted to the spindle core 41 and then transmitted to the nut 16, and the chuck 15 is loosened to achieve the purpose of tool loosening. The shell 32 and the push sheet 33 are connected by an O-shaped ring, the O-shaped ring has good sealing effect, and a proper amount of lubricating oil is smeared on the O-shaped ring to obtain a lower friction coefficient, so that the power loss of the cylinder during working is greatly reduced.

The cylinder block assembly 2 mainly comprises a cylinder block 201, a return spring 13 and various connectors. The cylinder block 201 has a complicated structure and plays a role of connecting the cylinder and the body 1 in the main shaft. The cylinder seat 201 is provided with a return spring 13 near the cylinder end, when the main shaft works, the return spring provides a return force for the cylinder to push the push sheet 33 to the end of the rear cover 31, so that when the main shaft operates, the nut 16 does not contact with the ejector rod 14, and the condition that the main shaft is blocked due to the fact that the ejector rod 14 contacts the nut 16 is avoided.

The air bearing assembly mainly comprises an air bearing 5, a throttling plug and an O-shaped sealing ring. An air inlet groove 9 is formed in the outer circle of the air bearing 5, and two circles of thirty-six first throttle holes 7 are formed in the end face of a flange 51 of the air bearing 5.

The body assembly mainly comprises a body 1, a coil 21, a cooling jacket of the coil 21, an inner jacket 42 and the like. The body 1 is the core part of the whole main shaft connected with the outside and is also the assembly main body of the whole main shaft core accessory. The body 1 is connected to the outside by a clasp (not shown). The coil 21 is axially and radially positioned by positioning holes of the coil 21 on the side surface of the body 1.

The rotor assembly 4 mainly comprises a shaft core 41, a shaft heater 18, a nut 16, a spring plate group, a nut 16 sleeve, a connecting rod (not shown in the figure), a squirrel cage 20 and the like, the squirrel cage 20 is in interference assembly connection with the shaft core 41 through the connecting rod, the squirrel cage 20 adopts an embedded squirrel cage 20, the production period is short, and the power and the torque of the motor are larger.

Wherein the thrust bearing assembly mainly comprises a thrust bearing 6 and a front cover. The thrust end face is provided with a water groove and an air groove 9 which form a closed cavity with the front cover, and when the main shaft runs, air pressure enters each throttling hole through the air groove 9 to provide axial thrust for the main shaft. The water channel forms a circulating water channel in the main shaft through the thrust bearing to cool all accessories of the main shaft. Two rows of thirty-six second throttle holes 8 are formed in the end face of the thrust bearing 6, and compressed air is input to provide axial thrust for the spindle during operation.

The main shaft body 1 is provided with cooling circulating water to ensure that the main shaft is in a normal temperature state during operation. When the spindle operates, airflow is sprayed to the ejector rod 14 and the nut 16 to the front end of the spindle through airflow externally connected with the rear cover 31, and powder and scraps cannot enter the spindle during tool changing, so that the interior of the spindle is in a dust-free state, and the service life of the spindle is greatly prolonged.

The highest rotating speed of the electric spindle can reach sixty thousand revolutions per minute.

The hybrid air bearing (air bearing 5) adopted by the main shaft is not in direct contact with the shaft core 41, so that the friction between a rotating part and a fixing part is avoided, the efficiency of the motor is improved, and the service life of the motor is prolonged. The front bearing and the rear bearing both adopt two circles of throttling holes, and the medium used by the front bearing and the rear bearing is air, so that the front bearing and the rear bearing are economical, environment-friendly, inexhaustible and inexhaustible. The end face of the bearing flange 51 and the end face of the thrust bearing 6 both adopt two rows of thirty-six orifices, so that the axial pushing and pulling forces of the main shaft are greatly increased, and the main shaft is not easy to block.

The main shaft thrust bearing 6 is in clearance fit with the shaft core 41, the fit clearance is 0.1-0.5mm, and the front cover, the shaft core 41 and the thrust bearing 6 form a labyrinth air path, so that air from the end face of the thrust bearing 6 forms an air cavity at the chamfer of the bearing flange 51, dust cannot enter the main shaft, and the main shaft is prevented from being locked and the service life is shortened.

The squirrel cage 20 on the main shaft core 41 adopts the embedded squirrel cage 20, the production period is short, and the power and the torque of the motor are larger. The shaft core 41 and the shaft heater 18 are connected through bolts, so that the shaft heater is convenient to disassemble and assemble and easy to replace.

The main shaft clamping cutter is from a spring sheet group (not shown in the figure), the spring sheet group consists of two spring sheets in one group, and seven groups of fourteen spring sheets in total, the two spring sheets are connected in series through a nut 16, and the nut 16 is in clearance fit with a shaft core 41.

The main shaft body 1 component adopts a spiral cooling water channel, the spiral groove 12 on the excircle of the inner sleeve 42 and the inner hole of the main body 1 form a closed spiral cavity, and the cooling water channel circularly flows through the coil 21 cooling sleeve, the main body 1 and the thrust bearing 6, so that heat generated by the whole main shaft during working is timely taken away by cooling circulating water.

The main shaft adopts a novel coil 21 structure, so that the main shaft has higher torque compared with the same main shaft at the same rotating speed.

The main shaft adopts the split type air cylinder, the thrust of the air cylinder can be increased by increasing the number of the air cylinders, and the size of the outer diameter of the air cylinder is reduced, so that the volume occupation ratio of the main shaft in the whole machine is greatly reduced. The dust is effectively controlled to enter the main shaft in the dust blowing gas circuit, and the failure rate of the main shaft during working is greatly reduced. The temperature sensor of the spindle can monitor the actual temperature of the spindle during working in real time, so that the normal work of the electric spindle is effectively protected.

The main shaft structure is provided with a circulating water path, and heat generated during the operation of the main shaft can be taken out in time. The main shaft adopts a novel winding mode of the coil 21, and has larger torque under the condition of the same rotating speed in the similar products. The highest rotating speed of the main shaft can reach sixty thousand revolutions per minute, and the stability of the same rotating speed can be achieved in the same products. The hybrid air bearing (air bearing 5) adopted by the main shaft is not in direct contact with the shaft core 41, so that the friction between a rotating part and a fixing part is avoided, the efficiency of the motor is improved, and the service life of the motor is prolonged. The front bearing and the rear bearing both adopt double exhaust holes, and the used medium is air, so the bearing is economical, environment-friendly, inexhaustible and inexhaustible. The end face of the bearing flange 51 and the end face of the thrust bearing 6 both adopt two rows of thirty-six orifices, so that the axial pushing and pulling forces of the main shaft are greatly increased, and the main shaft is not easy to block.

The embedded squirrel cage 20 used in the present spindle may also be a cast copper squirrel cage 20.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. High-speed air carving mills main shaft, be in including body, setting the cylinder block subassembly of body one end, bear cylinder block subassembly on the cylinder block subassembly sets up this internal rotor subassembly, the rotor subassembly includes that axle core and cover establish air bearing on the axle core, the axle core is kept away from the terminal surface of cylinder block subassembly is provided with footstep bearing, its characterized in that: the air cylinder seat assembly comprises an air cylinder seat and an air inlet joint arranged on the air cylinder seat, a flange is arranged at the end part of the air bearing and is close to the thrust bearing, a first throttling hole is formed in the end face of the flange, a second throttling hole is formed in the thrust bearing, an air flow channel is formed in the body, air flows from the air flow channel to the first throttling hole and the second throttling hole respectively and then is discharged, and the air bearing is separated from the shaft core by the air flow.

2. The high-speed air engraving and milling spindle of claim 1, wherein: an air inlet is formed in the circumferential surface of the air bearing and communicated with the first throttling hole.

3. The high-speed air engraving and milling spindle of claim 1, wherein: two circles of the first throttling holes are formed in the end face of the flange, the number of the first throttling holes in each circle is equal, and the number of the first throttling holes is thirty-six.

4. The high-speed air engraving and milling spindle of claim 1, wherein: two circles of the second throttling holes are formed in the end face of the thrust bearing, the number of the second throttling holes in each circle is equal, and the number of the second throttling holes is thirty-six.

5. The high-speed air engraving and milling spindle of claim 4, wherein: and one surface of the thrust bearing, which faces the shaft core, is provided with two circles of air grooves, the two circles of second throttling holes are arranged in the two circles of air grooves, and the air grooves are communicated with the air flow channel.

6. The high-speed air engraving and milling spindle of claim 1, wherein: the cylinder seat is further provided with a water inlet joint and a water outlet joint, an inner sleeve is arranged between the body and the shaft core, a spiral groove is formed in the circumferential surface of the inner sleeve, a cooling water path is formed between the spiral groove and the inner sleeve, two ends of the cooling water path are respectively communicated with the water inlet joint and the water outlet joint, and cooling liquid sequentially flows through the water inlet joint, the cooling water path and the water outlet joint.

7. The high-speed air engraving and milling spindle of claim 1, wherein: the air cylinder assembly comprises a rear cover, a shell, a plurality of push sheets and a plurality of spacers, wherein the shell is arranged on the air cylinder seat, the rear cover is arranged on the shell, and the push sheets and the spacers are arranged in the shell and the rear cover; and a sealing ring is connected between the shell and the push sheet.

8. The high-speed air engraving and milling spindle of claim 7, wherein: a reset spring is arranged at one end, close to the air cylinder, of the air cylinder seat, an ejector rod is arranged in the shaft core, a chuck is arranged at one end, far away from the air cylinder seat, of the ejector rod, the chuck is connected with a nut, and the nut is positioned between the ejector rod and the chuck; the reset spring is used for providing reset force for the air cylinder and pushing the push sheet to one end of the rear cover, so that the ejector rod and the nut are separated.

9. The high-speed air engraving and milling spindle of claim 8, wherein: the rear cover is provided with a tool changing air pressure joint which is communicated with the rear cover and the shell; the air current follow tool changing atmospheric pressure connects the flow direction ejector pin and nut, the air current follow avoid the dust to get into behind the nut outflow the axle core.

10. The high-speed air engraving and milling spindle of claim 1, wherein: the thrust bearing and the shaft core are in clearance fit, the end face of the thrust bearing is provided with a front cover, and the front cover, the shaft core and the thrust bearing form a labyrinth gas circuit.