Electric spindle

Abstract

The motorized spindle comprises a machine body assembly, a spindle core, a pulling claw assembly and a tool loosening and broaching mechanism, the pulling claw assembly comprises a sliding core, a clamping head is arranged at the rear end of the sliding core, the tool loosening and broaching mechanism comprises a first driving cylinder, a second driving cylinder and a pull rod, and the first driving cylinder is arranged at the rear end of the machine body assembly; the second driving cylinder is arranged at the rear end of the first driving cylinder, an axial connecting rod for transmitting axial force is arranged between a piston of the first driving cylinder and a piston of the second driving cylinder, the rear end of the pull rod is connected to the piston of the first driving cylinder, the front end of the pull rod extends into an inner hole of the shaft core, a clamping groove is formed in the front end of the pull rod, and the clamping connector is connected to the clamping groove. The clamping groove is provided with a clamping face capable of pulling the clamping head from the front side and an abutting face capable of abutting against the clamping head from the rear side, and an axial interval allowing the clamping head to move in the axial direction is formed between the abutting face and the clamping face. By adopting a disc-spring-free type locking structure, the problem of cutter loosening caused by failure of a disc spring is solved.

Description

Technical Field

[0001] The invention is used in the technical field of spindle machining, and particularly relates to an electric spindle. Background Art

[0002] With the demand for economic development and technological take-off, more and more new technologies are emerging, and the mechanical processing industry is also emerging. In particular, the leading spindle industry has very obvious technological innovation. Due to the increasing precision of the molding and processing of automotive optical molds and the high-light industry, the spindle is forced to develop in the direction of high speed and high precision. The traditional ball bearing electric spindle is subject to the limitations of the bearing, and its speed and precision are difficult to further improve. Therefore, the high speed and high precision of the spindle industry must be developed on the air bearing spindle. Because the air bearing has the characteristics of low friction, low loss, and error averaging, the spindle using air bearings has become one of the best carriers for ultra-precision machining.

[0003] However, the air-floating spindle generally uses elastic components such as disc springs to tighten the tool handle. This tool handle tightening method has the problem of tool loosening due to disc spring failure.

[0004] In addition, the existing electric spindle has inherent deficiencies in its structural setting, which makes it difficult to further improve its speed and accuracy. Moreover, the spindle stator and shaft core will generate a lot of heat during high-speed rotation, and how to effectively remove the heat is also a difficulty. Summary of the invention

[0005] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide an electric spindle.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] 1. The invention relates to an electric spindle, comprising a body assembly, a shaft core, a claw assembly and a tool loosening and broaching mechanism, wherein the shaft core is rotatably mounted on the body assembly, the shaft core is provided with a shaft core inner hole, the claw assembly is arranged at the front end of the shaft core inner hole, the claw assembly comprises a sliding core, a clamping joint is arranged at the rear end of the sliding core, and the tool loosening and broaching mechanism comprises a first driving cylinder, a second driving cylinder and a pull rod, the first driving cylinder is arranged at the rear end of the body assembly, the second driving cylinder is arranged at the rear end of the first driving cylinder, an axial connecting rod for transmitting axial force is arranged between the piston of the first driving cylinder and the piston of the second driving cylinder, the rear end of the pull rod is connected to the piston of the first driving cylinder, the front end of the pull rod extends into the shaft core inner hole, the front end of the pull rod is provided with a clamping groove, the clamping joint is connected to the clamping groove, the clamping groove is provided with a clamping surface capable of pulling the clamping joint from the front side and a push surface capable of resisting the clamping joint from the rear side, an axial gap is formed between the push surface and the clamping surface for the clamping joint to move axially.

[0008] In combination with the above implementations, in some implementations, the body assembly includes a body outer shell, a stator mounting seat, a first air-floating bearing seat and a second air-floating bearing seat, the body outer shell is provided with a body inner hole extending axially from a first end to a second end, the stator mounting seat is mounted on the body inner hole by the first end of the body outer shell, the second air-floating bearing seat is mounted on the body inner hole by the second end of the body outer shell, the first air-floating bearing seat is arranged in the body inner hole and is clamped between the stator mounting seat and the second air-floating bearing seat, the first air-floating bearing seat is provided with a first radial air-floating bearing, and the second air-floating bearing seat is provided with a second radial The first air-floating bearing seat is provided with a first thrust bearing assembly at one end close to the second air-floating bearing seat, and the second air-floating bearing seat is provided with a second thrust bearing assembly at one end close to the first air-floating bearing seat. The shaft core is supported on the body assembly through the first radial air-floating bearing and the second radial air-floating bearing. The shaft core is provided with a flying disc that cooperates with the first thrust bearing assembly and the second thrust bearing assembly. The stator mounting seat is provided with a motor cavity behind the first air-floating bearing seat, and the stator mounting seat is provided with a stator in the motor cavity. The shaft core extends into the motor cavity and is provided with a rotor that cooperates with the stator.

[0009] In combination with the above-mentioned implementations, in some implementations, the stator mounting seat, the first air-floating bearing seat and the second air-floating bearing seat form an outer circumferential surface extending continuously along the axial direction inside the inner hole of the body, and the outer circumferential surface is in contact with the inner wall of the inner hole of the body, and the outer circumferential surfaces of the stator mounting seat, the first air-floating bearing seat and the second air-floating bearing seat are provided with a cooling liquid groove extending continuously as a whole.

[0010] In combination with the above implementations, in certain implementations, the cooling liquid groove includes a spiral groove, the spiral groove includes an inlet cooling liquid groove and a return cooling liquid groove, the inlet cooling liquid groove extends from the first end of the body jacket toward the second end, the return cooling liquid groove extends from the second end of the body jacket toward the first end, the stator mounting seat is provided with a cooling liquid inlet connected to the inlet cooling liquid groove, and the stator mounting seat is provided with a cooling liquid outlet connected to the return cooling liquid groove.

[0011] In combination with the above-mentioned implementation methods, in some implementation methods, the first end of the first air-floating bearing seat has a first boss extending axially, the first air-floating bearing seat is provided with a first axial step surface on the outer side of the first boss, the stator mounting seat has a first sleeve portion extending axially, the first sleeve portion is sleeved on the first boss, the end of the first sleeve portion abuts the first axial step surface, a first sealing ring is provided between the first air-floating bearing seat and the stator mounting seat, the second end of the first air-floating bearing seat has a second boss extending axially, the first air-floating bearing seat is provided with a second axial step surface on the outer side of the second boss, the second air-floating bearing seat has a second sleeve portion extending axially, the second sleeve portion is sleeved on the second boss, the end of the second sleeve portion abuts the second axial step surface, and a second sealing ring is provided between the first air-floating bearing seat and the second air-floating bearing seat.

[0012] In combination with the above implementations, in certain implementations, the first air bearing seat and the second air bearing seat are provided with honeycomb-shaped axial heat dissipation holes.

[0013] In combination with the above-mentioned implementations, in certain implementations, the first thrust bearing assembly and the second thrust bearing assembly both include a first thrust bearing annular component and a second thrust bearing annular component, the first thrust bearing annular component and the second thrust bearing annular component form a flush axial thrust surface, and a throttling gap is formed between the first thrust bearing annular component and the second thrust bearing annular component on the axial thrust surface for ejecting thrust airflow.

[0014] In combination with the above-mentioned implementations, in some implementations, the first radial air bearing is interference-fitted in the first air bearing seat and then integrally processed to form an axial hole for mounting the shaft core, the second radial air bearing is interference-fitted in the second air bearing seat and then integrally processed to form an axial hole for mounting the shaft core, and the first thrust bearing annular component and the second thrust bearing annular component are installed in the first air bearing seat and the second air bearing seat and then integrally processed to form a flush axial thrust surface.

[0015] In combination with the above-mentioned implementation manner, in some implementation manners, the rear end of the stator mounting seat is provided with a concave cavity extending forward in the axial direction, the first drive cylinder includes a first cylinder head arranged in the concave cavity, the first cylinder head defines a first piston cavity inside the concave cavity, the piston of the first drive cylinder is arranged in the first piston cavity, the front end of the axial connecting rod is connected to the piston of the first drive cylinder, the rear end of the axial connecting rod extends toward the second drive cylinder through the first cylinder head, the second drive cylinder includes a cylinder body and a second cylinder head, the cylinder body is connected to the rear end of the concave cavity, the cylinder body is provided with a second piston cavity, the piston of the second drive cylinder is arranged in the second piston cavity, and the piston of the second drive cylinder is provided with a push rod extending toward the axial connecting rod through the second cylinder head.

[0016] In combination with the above-mentioned implementation methods, in some implementation methods, a shank mounting hole is provided at the front end of the inner hole of the shaft core, and the claw assembly also includes a claw fixing ring, an elastic component, a gasket and multiple claw components. The claw fixing ring is installed in the inner hole of the shaft core, and the claw fixing ring is provided with multiple claw mounting grooves along the circumferential direction. Multiple claw components are inserted into the claw mounting grooves, and the front end of the sliding core is inserted into the claw fixing ring, the gasket is arranged on the rear side of the claw component, the elastic component is mounted on the sliding core and presses the gasket from the rear side, and the sliding core is provided with an avoidance groove that cooperates with the claw.

[0017] One of the above technical solutions has at least one of the following advantages or beneficial effects: In the technical solution of the present invention, when the tool is pulled, the piston of the first drive cylinder moves backward with the pull rod, and the pull rod pulls the clamping joint of the sliding core through the clamping surface of the clamping groove, so that the sliding core also moves backward together, and further cooperates with the claw assembly to lock the tool handle to the front end of the shaft core. At this time, the first drive cylinder releases pressure, and the second drive cylinder moves and pushes the piston and pull rod of the first drive cylinder to move forward a certain distance through the axial connecting rod, so that the clamping joint is separated from the push surfaces and clamping surfaces on both sides, so that the pull rod and the sliding core avoid interference, and the shaft core can operate in this state. When loosening the tool, the piston of the first drive cylinder moves forward with the pull rod, and the push surface of the pull rod abuts against the sliding core and pushes the sliding core to move forward together, and further cooperates with the claw assembly to loosen the tool handle, so that the tool can be replaced. In the technical solution of the present invention, the first drive cylinder and the second drive cylinder work together, and the pull rod and the sliding core cooperate to achieve the function of loosening the tool. It solves the problem of loosening the tool caused by failure of the disc spring by adopting a disc spring-free locking structure.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention;

[0021] Figure 2 It is a schematic diagram of the coordination structure of a stator mounting seat, a first air-floating bearing seat and a second air-floating bearing seat in one embodiment of the present invention;

[0022] Figure 3 It is a schematic diagram of the structure of a first air bearing seat according to an embodiment of the present invention;

[0023] Figure 4 It is a schematic diagram of the structure of a second air bearing seat according to an embodiment of the present invention;

[0024] Figure 5 It is a schematic diagram of the structure of a loosening and broaching mechanism according to an embodiment of the present invention;

[0025] Figure 6 It is a schematic diagram of the structure of the shaft core and the claw assembly of an embodiment of the present invention;

[0026] Figure 7 It is a schematic structural diagram of a first air bearing assembly according to an embodiment of the present invention;

[0027] Figure 8 It is a schematic structural diagram of a second air bearing assembly according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0029] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention.

[0030] In the present invention, "several" means one or more, "multiple" means more than two, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. In the description of the present invention, if there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0031] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected or electrically connected or able to communicate with each other; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0032] in, Figure 1 and Figure 5 The reference direction coordinate system of the embodiment of the present invention is given. Figure 1 and Figure 5 The embodiment of the present invention is described with reference to the direction shown.

[0033] See also Figure 1 , Figure 5 , Figure 6The embodiment of the present invention provides an electric spindle, including a body assembly, a shaft core 600, a claw assembly 800 and a tool loosening and pulling mechanism 900, wherein the shaft core 600 is rotatably mounted on the body assembly, the shaft core 600 is provided with a shaft core inner hole 603, the claw assembly 800 is arranged at the front end of the shaft core inner hole 603, and connects the tool handle to the front end of the shaft core 600, the claw assembly 800 includes a sliding core 801, and a card joint 802 is provided at the rear end of the sliding core 801, and the tool loosening and pulling mechanism 900 includes a first driving cylinder, a second driving cylinder and a pull rod 901, the first driving cylinder is arranged at the rear end of the body assembly, and the second driving cylinder is arranged at the first driving cylinder. At the rear end of the cylinder, an axial connecting rod 902 for transmitting axial force is provided between the piston of the first driving cylinder and the piston of the second driving cylinder, the stroke of the first driving cylinder is greater than the stroke of the second driving cylinder, the rear end of the pull rod 901 is connected to the piston of the first driving cylinder, the front end of the pull rod 901 extends into the inner hole 603 of the shaft core, the front end of the pull rod 901 is provided with a card slot, the card joint 802 is connected to the card slot, the card slot is provided with a card surface 903 that can pull the card joint 802 from the front side and a push surface 904 that can push against the card joint 802 from the back side, and an axial interval is formed between the push surface 904 and the card surface 903 for the card joint 802 to move axially. In other words, the card joint 802 can only abut against the push surface 904 or only abut against the card surface 903 or not abut against both the push surface 904 and the card surface 903. The first drive cylinder can be an oil cylinder, a pneumatic cylinder, etc. The piston of the first drive cylinder can move from the front end of the first drive cylinder to the rear end of the first drive cylinder, or from the rear end of the first drive cylinder to the front end of the first drive cylinder during operation, but cannot stay at a position between the front end and the rear end of the first drive cylinder.

[0034] Combination Figure 1 , Figure 5In the technical solution of the present invention, when the tool is being broached, the piston of the first driving cylinder moves backward with the pull rod 901, and the pull rod 901 pulls the clamping joint 802 of the sliding core 801 through the clamping surface 903 of the clamping groove, so that the sliding core 801 also moves backward together, and further cooperates with the claw assembly 800 to lock the tool handle to the front end of the shaft core 600. At this time, the first driving cylinder releases pressure, and the second driving cylinder is actuated and pushes the piston of the first driving cylinder and the pull rod 901 forward a certain distance through the axial connecting rod 902, so that the clamping joint 802 is separated from the push surfaces 904 and the clamping surfaces 903 on both sides, so that the pull rod 901 and the sliding core 801 avoid interference, and the shaft core 600 can operate in this state. When loosening the tool, the piston of the first drive cylinder moves forward with the pull rod 901, and the push surface 904 of the pull rod 901 abuts against the sliding core 801, and pushes the sliding core 801 to move forward together, and further cooperates with the claw assembly 800 to loosen the tool handle, so that the tool can be replaced. The technical solution of the present invention uses the first drive cylinder and the second drive cylinder to work together, and at the same time combines the cooperation between the pull rod 901 and the sliding core 801 to achieve the function of loosening the tool. It adopts a disc spring-free locking structure to solve the problem of loosening the tool caused by disc spring failure.

[0035] In some embodiments, see Figure 1 , Figure 2The body assembly includes a body jacket 100, a stator mounting seat 200, a first air-floating bearing seat 300 and a second air-floating bearing seat 400. The body jacket 100 is sleeve-shaped. The body jacket 100 extends axially from a first end 101 to a second end 102. The body jacket 100 is provided with an inner hole 103 of the body extending axially from the first end 101 to the second end 102. The stator mounting seat 200 is mounted in the inner hole 103 of the body by the first end 101 of the body jacket 100. The stator mounting seat 200 can be connected to the body jacket 100 by means of threads, pins, screws, etc. The second air-floating bearing seat 400 is mounted in the inner hole 103 of the body by the second end 102 of the body jacket 100. The second air-floating bearing seat 400 can be mounted in the inner hole 103 of the body by means of threads, pins, screws, etc. The first air-floating bearing seat 300 is connected to the body jacket 100 by means of nails or the like, and the first air-floating bearing seat 300 is arranged in the body hole 103 and is clamped between the stator mounting seat 200 and the second air-floating bearing seat 400. In other words, one end of the first air-floating bearing seat 300 abuts against the stator mounting seat 200, and the other end of the first air-floating bearing seat 300 abuts against the second air-floating bearing seat 400. The first air-floating bearing seat 300 is provided with a first radial air-floating bearing 301, and the second air-floating bearing seat 400 is provided with a second radial air-floating bearing 401. The first air-floating bearing seat 300 is provided with a first thrust bearing assembly 302 at one end close to the second air-floating bearing seat 400, and the second air-floating bearing seat 400 is provided with a second thrust bearing assembly 401 at one end close to the first air-floating bearing seat 300. The shaft core 600 is supported on the electric spindle body assembly through the first radial air bearing 301 and the second radial air bearing 401. The shaft core 600 is provided with a flying disc 601 that cooperates with the first thrust bearing assembly 302 and the second thrust bearing assembly 401. Figure 7 The first radial air bearing 301 and the first thrust bearing assembly 302 are arranged on the first air bearing seat 300 to form a first air bearing assembly. Figure 8 The second radial air bearing 401 and the second thrust bearing assembly 401 are arranged on the second air bearing seat 400 to form a second air bearing assembly.

[0036] The high-pressure air passes through the air flow channel of the body assembly and enters the damping plugs of the first radial air bearing 301 and the second radial air bearing 401. The damping plugs are all micro-pore throttling with the same aperture size. After passing through the micro-pores, the high-pressure air diffuses to the surroundings, so that a layer of high-pressure air film is formed between the shaft core and the first radial air bearing 301 and the second radial air bearing 401. At the same time, it enters the slit throttling of the first thrust bearing assembly 302 and the second thrust bearing assembly 401, so that a layer of high-pressure air film is also formed between the flying disc position of the shaft core and the thrust bearing assembly. The high-pressure air film between the first radial air bearing 301, the second radial air bearing 401, the thrust bearing assembly and the shaft core supports the contactless suspension of the shaft core and ensures that the shaft core has a certain load-bearing capacity and rigidity.

[0037] The stator mounting seat 200 is provided with a motor cavity 205 behind the first air bearing seat 300. The stator mounting seat 200 is provided with a stator 204 in the motor cavity 205. The shaft core 600 extends into the motor cavity 205 and is provided with a rotor 602 that cooperates with the stator 204. The motor is formed with the stator 204. For example, in some embodiments, the motor adopts a slotless permanent magnet synchronous motor, which is controlled by a driver to drive the entire shaft core 600 to rotate at high speed.

[0038] Combination Figure 1 , Figure 2 In the technical solution of the present invention, the stator mounting seat 200 and the second air-floating bearing seat 400 are respectively mounted on the two ends of the body jacket 100, and the first air-floating bearing seat 300 is clamped by the stator mounting seat 200 and the second air-floating bearing seat 400 on both sides. The electric spindle body assembly adopts an integrated clamping structure design to reduce abnormal assembly of parts and components and facilitate overall disassembly for dynamic balancing. At the same time, the thrust bearing assembly is arranged between the first air-floating bearing seat 300 and the second air-floating bearing seat 400, that is, a central structure of the shaft core flying disc is formed, which can enable the spindle to obtain higher rigidity, keep the thrust bearing assembly away from the rotor position, reduce the influence of thermal deformation on the shaft core, and improve the stability of the shaft system. The embodiments of the present invention improve the rigidity and precision of the spindle.

[0039] In some embodiments, see Figure 1 , Figure 2 The stator mounting seat 200, the first air bearing seat 300 and the second air bearing seat 400 form an outer circumferential surface 500 extending continuously in the axial direction inside the inner hole 103 of the machine body, and the outer circumferential surface 500 is in contact with the inner wall of the inner hole 103 of the machine body. The outer circumferential surfaces 500 of the stator mounting seat 200, the first air bearing seat 300 and the second air bearing seat 400 cooperate with the machine body outer shell 100 to form a stable overall structure, reduce abnormal assembly of parts, and facilitate overall disassembly for dynamic balancing.

[0040] During the high-speed rotation of the main shaft stator and the shaft core, a large amount of heat will be generated. How to effectively remove the heat is a difficult point. In some embodiments, see Figure 1 , Figure 2 , Figure 3 , Figure 4The outer circumferential surfaces 500 of the stator mounting seat 200, the first air-floating bearing seat 300 and the second air-floating bearing seat 400 are provided with a cooling liquid groove 501 which extends continuously as a whole. In other words, the cooling liquid groove 501 of the outer circumferential surface 500 of the stator mounting seat 200, the cooling liquid groove 501 of the outer circumferential surface 500 of the first air-floating bearing seat 300 and the cooling liquid groove 501 of the outer circumferential surface 500 of the second air-floating bearing seat 400 are connected in sequence to form a cooling liquid groove 501 which extends continuously as a whole. The cooling liquid groove 501 cooperates with the outer body jacket 100 to form a continuously extending cooling channel. The cooling channel is connected as a whole at the outer circumferential surfaces 500 of the stator mounting seat 200, the first air-floating bearing seat 300 and the second air-floating bearing seat 400 to ensure that the cooling area is maximized. This structure can timely bring the heat of the spindle product out of the shaft to the maximum extent, reduce the influence of heat on the shaft core during high-speed operation, and ensure the safety of high-speed operation of the spindle.

[0041] The cooling liquid tank 501 can be arranged in a U-shaped or spiral shape on the outer circumferential surface 500 of the stator mounting seat 200, the first air bearing seat 300 and the second air bearing seat 400. In some embodiments, see Figure 2 The cooling liquid groove 501 includes a spiral groove, which spirally surrounds the outer circumferential surface 500 of the stator mounting seat 200, the first air-floating bearing seat 300 and the second air-floating bearing seat 400, and is connected as a whole. The spiral groove includes a liquid inlet cooling liquid groove and a liquid return cooling liquid groove. The liquid inlet cooling liquid groove extends from the first end 101 of the body jacket 100 to the second end 102, and the liquid return cooling liquid groove extends from the second end 102 of the body jacket 100 to the first end 101. The stator mounting seat 200 is provided with a cooling liquid inlet 201 connected to the liquid inlet cooling liquid groove, and the stator mounting seat 200 is provided with a cooling liquid outlet 202 connected to the liquid return cooling liquid groove. When working, the cooling liquid enters from the cooling liquid inlet 201, flows through the liquid inlet cooling liquid groove and the liquid return cooling liquid groove, and then flows out from the cooling liquid outlet, so that the heat of the spindle product is timely taken out of the shaft, reducing the influence of heat on the shaft core component when running at high speed, and ensuring the safety of the high-speed operation of the spindle.

[0042] In some embodiments, see Figure 1The first end of the first air-floating bearing seat 300 has a first boss 303 extending in the axial direction. The first air-floating bearing seat 300 is provided with a first axial step surface 304 on the outer side of the first boss 303. The stator mounting seat 200 has a first sleeve portion 203 extending in the axial direction. The first sleeve portion 203 is sleeved on the first boss 303. The end of the first sleeve portion 203 abuts against the first axial step surface 304. A first sealing ring is provided between the first air-floating bearing seat 300 and the stator mounting seat 200. The first air-floating bearing seat 300 and the stator mounting seat 200 are connected to each other by radial sleeve connection and axial abutment, so as to fully ensure the assembly accuracy between the first air-floating bearing seat 300 and the stator mounting seat 200. At the same time, the sealing between the first air-floating bearing seat 300 and the stator mounting seat 200 is ensured by means of the first sealing ring, so as to prevent the cooling liquid from leaking between the first air-floating bearing seat 300 and the stator mounting seat 200.

[0043] In some embodiments, see Figure 1 The second end of the first air-floating bearing seat 300 has a second boss 305 extending in the axial direction, and the first air-floating bearing seat 300 is provided with a second axial step surface 306 on the outer side of the second boss 305. The second air-floating bearing seat 400 has a second sleeve portion 402 extending in the axial direction, and the second sleeve portion 402 is sleeved on the second boss 305, and the end of the second sleeve portion 402 abuts against the second axial step surface 306. A second sealing ring is provided between the first air-floating bearing seat 300 and the second air-floating bearing seat 400. The second air-floating bearing seat 400 and the first air-floating bearing seat 300 are connected by radial sleeve connection and axial abutment, so as to fully ensure the assembly accuracy between the first air-floating bearing seat 300 and the second air-floating bearing seat 400. At the same time, the sealing between the first air-floating bearing seat 300 and the second air-floating bearing seat 400 is ensured by means of the second sealing ring, so as to prevent the coolant from leaking between the first air-floating bearing seat 300 and the second air-floating bearing seat 400.

[0044] In some embodiments, see Figure 3 , Figure 4 The first air bearing seat 300 and the second air bearing seat 400 are provided with honeycomb-shaped axial heat dissipation holes 307 and 403, which further increase the heat dissipation area, further reduce the influence of heat on the shaft core assembly during high-speed operation, and ensure the safety of high-speed operation of the main shaft.

[0045] In some embodiments, see Figure 1The first air bearing seat 300 is provided with a first flange 308 that matches the axial end face of the first end of the body jacket 100. The first flange 308 is located outside the body inner hole 103. The first flange 308 is assembled to the first end of the body jacket 100 through a first fastener 309. The first fastener 309 can be a screw, a bolt, etc. Similarly, the second air bearing seat 400 is provided with a second flange 404 that matches the axial end face of the second end of the body jacket 100. The second flange 404 is located outside the body inner hole 103. The second flange 404 is assembled to the second end of the body jacket 100 through a second fastener 405. The second fastener can be a screw, a bolt, etc. In this embodiment, by axially locking the first fastener 309 and the second fastener 405, the stator mounting seat 200, the first air bearing seat 300 and the second air bearing seat 400 can be clamped in an integrated manner in the body jacket 100.

[0046] The first thrust bearing assembly 302 and the second thrust bearing assembly 401 are used to cooperate with the flying disc of the shaft core, so that a layer of high-pressure air film is also formed between the flying disc position and the thrust bearing assembly.

[0047] In some embodiments, see Figure 1 , Figure 7 , Figure 8 The first thrust bearing assembly 302 and the second thrust bearing assembly 401 both include a first thrust bearing annular component 310, 406 and a second thrust bearing annular component 311, 407. The first thrust bearing annular component 310, 406 and the second thrust bearing annular component 311, 407 form a flush axial thrust surface. A throttling gap 312, 408 for ejecting thrust airflow is formed between the first thrust bearing annular component 310, 406 and the second thrust bearing annular component 311, 407 on the axial thrust surface. In this embodiment, the throttling gap for ejecting thrust airflow is formed by the matching gap between the first thrust bearing annular component and the second thrust bearing annular component. The structure is simpler, and there is no need to set an axial damping hole on the first thrust bearing assembly 302 and the second thrust bearing assembly 401. Moreover, the throttling gap can extend continuously in the circumferential direction, so that a better high-pressure air film can be obtained.

[0048] The throttling slots 312 and 408 may extend in a circular or wavy shape along the circumferential direction. In some embodiments, see Figure 7 , Figure 8The first thrust bearing annular component 310, 406 is provided with an outer circumferential surface, the second thrust bearing annular component 311, 407 is provided with an inner circumferential surface, the second thrust bearing annular component 311, 407 is sleeved on the first thrust bearing annular component 310, 406, and a throttling gap 312, 408 is formed between the outer circumferential surface of the first thrust bearing annular component 310, 406 and the inner circumferential surface of the second thrust bearing annular component 311, 407. The axis of the outer circumferential surface of the first thrust bearing annular component 310, 406 and the inner circumferential surface of the second thrust bearing annular component 311, 407 coincide with each other, so that it is easier to obtain a throttling gap with better uniformity, ensuring that the air-floating thrust bearing has uniform axial air film stiffness along the circumferential direction.

[0049] In some embodiments, see Figure 7-Figure 8 The first thrust bearing annular component 310, 406 is provided with radial flanges 312, 409 that abut against the second thrust bearing annular component 311, 407 from the rear side in the axial direction. The first thrust bearing annular component 310, 406 forms a groove-shaped space on the front side of the radial flanges 316, 409, and the second thrust bearing annular component 311, 407 can be installed in the groove-shaped space, achieving precise positioning and stable installation in the axial and radial directions.

[0050] Further, see Figure 7-Figure 8 The first thrust bearing assembly 302 and the second thrust bearing assembly 401 are correspondingly installed on the first air-floating bearing seat 300 and the second air-floating bearing seat 400 by screws. The radial flanges 316, 409 and the second thrust bearing annular components 311, 407 are provided with axial screw holes at corresponding positions. The axial screw holes of the radial flanges 316, 409 are through holes, and the axial screw holes of the second thrust bearing annular components 311, 407 are blind holes. The screws pass through the axial screw holes of the radial flanges 316, 409 and are connected to the axial screw holes of the second thrust bearing annular components 311, 407, and the first thrust bearing annular components 310, 406 and the second thrust bearing annular components 311, 407 are locked to the first air-floating bearing seat 300 and the second air-floating bearing seat 400. The first thrust bearing annular components 310, 406 and the second thrust bearing annular components 311, 407 are integrally processed to form flush axial thrust surfaces. In this embodiment, the first thrust bearing annular component 310, 406 and the second thrust bearing annular component 311, 407 are integrally processed after being assembled, which can effectively improve the radial and axial shape and position tolerances of the bearing and improve the accuracy and stability of the air bearing.

[0051] In some embodiments, see Figure 7 , Figure 8The outer circumferential surface of the first thrust bearing annular component 310, 406 is provided with a first annular groove 313, 410 and a plurality of air inlet holes 314, 411 communicating with the first annular groove 313, 410, the air inlet holes 314, 411 extend to the tail end surface of the first thrust bearing annular component 310, 406, the tail end surface of the first thrust bearing annular component 310, 406 is provided with a second annular groove 315, 412 communicating with the air inlet holes 314, 411, the second annular groove 315, 412, the air inlet holes 314, 411 and the first annular groove 313, 410 form an air inlet channel. The air inlet channel of this embodiment can fully ensure the uniformity of the airflow overflowing from the throttling gap.

[0052] Further, see Figure 7 , Figure 8 The first annular groove 313, 410 divides the outer circumferential surface of the first thrust bearing annular component 310, 406 into a first outer circumferential surface and a second outer circumferential surface in the axial direction. The first outer circumferential surface is closer to the axial thrust surface than the second outer circumferential surface. The inner circumferential surface of the second thrust bearing annular component 311, 407 is clearance-fitted with the first outer circumferential surface, and the inner circumferential surface of the second thrust bearing annular component 311, 407 is interference-fitted with the second outer circumferential surface. The first thrust bearing annular component 310, 406 and the second thrust bearing annular component 311, 407 are interference-fitted at the second outer circumferential surface, thereby further ensuring the uniformity of the throttling gap at the first outer circumferential surface between the first thrust bearing annular component 310, 406 and the second thrust bearing annular component 311, 407.

[0053] In some embodiments, see Figure 7 , Figure 8 The first radial air bearing 301 is interference-fitted into the first air bearing seat 300 and then integrally processed to form an axial hole for installing the shaft core 600. The second radial air bearing 401 is interference-fitted into the second air bearing seat 400 and then integrally processed to form an axial hole for installing the shaft core 600. This embodiment adopts a solution of assembling first and then processing, which can effectively improve the radial and axial perpendicularity of the bearing, and improve the spindle stiffness, precision, etc.

[0054] In some embodiments, see Figure 5The rear end of the stator mounting seat 200 is provided with a concave cavity 206 extending forward in the axial direction. The first driving cylinder includes a first cylinder head 905 arranged in the concave cavity 206. The first cylinder head 905 defines a first piston cavity 906 inside the concave cavity 206. The piston 907 of the first driving cylinder is arranged in the first piston cavity 906. The front end of the axial connecting rod 902 is connected to the piston 907 of the first driving cylinder. The rear end of the axial connecting rod 902 extends toward the second driving cylinder through the first cylinder head 905. The second driving cylinder includes a cylinder body 908 and a second cylinder head 909. The cylinder body 908 is connected to the rear end of the concave cavity 206. A second piston cavity 910 is provided in the cylinder body 908. The piston 911 of the second driving cylinder is arranged in the second piston cavity 910. The piston 911 of the second driving cylinder is provided with a push rod 912 extending toward the axial connecting rod 902 through the second cylinder head 909. In this embodiment, the first drive cylinder and the second drive cylinder are disposed in the concave cavity 206 of the stator mounting seat 200, which can effectively shorten the axial length of the entire electric spindle, make the structure more compact, and better ensure coordinated action.

[0055] In some embodiments, see Figure 6 A tool handle mounting hole is provided at the front end of the shaft core inner hole 603, and the tool handle mounting hole adopts a tapered hole. The claw assembly also includes a claw fixing ring 803, an elastic component 804, a gasket 805 and multiple claw components 806. The claw fixing ring 803 is installed in the shaft core inner hole 603, and the claw fixing ring 803 is provided with multiple claw mounting grooves along the circumferential direction. Multiple claw components 806 are inserted into the claw mounting grooves. The front end of the sliding core 801 is inserted into the claw fixing ring 803, and the gasket 805 is arranged on the rear side of the claw component 806. The elastic component 804 is sleeved on the sliding core 801 and resists the gasket 805 from the rear side. The elastic component 804 is used to pre-tighten the various parts of the claw assembly into a whole, which is convenient for assembly in the shaft core. The sliding core 801 is provided with an avoidance groove that cooperates with the claw.

[0056] When the front chamber of the first driving cylinder is connected to high pressure gas, the piston 907 moves backward with the pull rod 901, the pull rod 901 is connected to the sliding core 801 by a slot, and the sliding core 801 also moves backward together. When the sliding core 801 moves backward, the inner side of the pull claw is spread out by the corresponding avoidance groove on the sliding core 801, and the outer end of the pull claw is stuck in the corresponding inclined groove of the handle. At this time, the sliding core 801, the pull claw, and the handle 807 generate a locking force due to deformation, and the handle is in a locked state. When the rear chamber of the first driving cylinder is connected to high pressure gas, the piston moves forward with the pull rod 901, the pull rod 901 is connected to the sliding core 801 by a slot, and the sliding core 801 also moves forward together. When the sliding core 801 moves forward, the inner side of the pull claw slides into the avoidance groove along the corresponding position matched with the sliding core 801, and one end of the pull claw avoids the inclined groove of the handle, so that the handle can be loosened and the tool can be replaced.

[0057] It is understandable that the claw assembly may also adopt solutions such as a steel column claw, an integrated claw, etc.

[0058] In some embodiments, see Figure 1 The electric spindle is provided with a cover plate 700 at the end of the electric spindle body assembly, and a small gap 701 is left between the cover plate 700 and the front end of the shaft core 600. The gas in the system can flow to the outside through the gap, and it also plays a role of air sealing to prevent dust from entering the spindle during processing, thereby extending the service life of the spindle. At the same time, it can also blow away the residue on the workpiece surface and improve the surface processing effect.

[0059] In the description of this specification, the description with reference to the terms "example", "embodiment" or "some embodiments" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0060] Of course, the invention is not limited to the above-mentioned embodiments, and those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the invention, and these equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. An electric spindle, characterized in that: The invention comprises a body assembly, an axis core, a claw assembly and a tool loosening and broaching mechanism, wherein the axis core is rotatably mounted on the body assembly, the axis core is provided with an axis core inner hole, the claw assembly is arranged at the front end of the axis core inner hole, the claw assembly comprises a sliding core, a clamping joint is arranged at the rear end of the sliding core, and the tool loosening and broaching mechanism comprises a first driving cylinder, a second driving cylinder and a pulling rod, the first driving cylinder is arranged at the rear end of the body assembly, the second driving cylinder is arranged at the rear end of the first driving cylinder, an axial connecting rod for transmitting axial force is arranged between the piston of the first driving cylinder and the piston of the second driving cylinder, the rear end of the pulling rod is connected to the piston of the first driving cylinder, the front end of the pulling rod extends into the axis core inner hole, the front end of the pulling rod is provided with a clamping groove, the clamping joint is connected to the clamping groove, the clamping groove is provided with a clamping surface capable of pulling the clamping joint from the front side and a pushing surface capable of resisting the clamping joint from the rear side, an axial gap is formed between the pushing surface and the clamping surface for the clamping joint to move axially.

2. The electric spindle according to claim 1, characterized in that: The body assembly includes a body outer shell, a stator mounting seat, a first air-floating bearing seat and a second air-floating bearing seat. The body outer shell is provided with a body inner hole extending axially from a first end to a second end. The stator mounting seat is mounted on the body inner hole by the first end of the body outer shell. The second air-floating bearing seat is mounted on the body inner hole by the second end of the body outer shell. The first air-floating bearing seat is arranged in the body inner hole and is clamped between the stator mounting seat and the second air-floating bearing seat. The first air-floating bearing seat is provided with a first radial air-floating bearing. The second air-floating bearing seat is provided with a second radial air-floating bearing. An air-floating bearing seat is provided with a first thrust bearing assembly at one end close to the second air-floating bearing seat, and the second air-floating bearing seat is provided with a second thrust bearing assembly at one end close to the first air-floating bearing seat. The shaft core is supported on the body assembly through the first radial air-floating bearing and the second radial air-floating bearing. The shaft core is provided with a flying disc that cooperates with the first thrust bearing assembly and the second thrust bearing assembly. The stator mounting seat is provided with a motor cavity behind the first air-floating bearing seat, and the stator mounting seat is provided with a stator in the motor cavity. The shaft core extends into the motor cavity and is provided with a rotor that cooperates with the stator.

3. The electric spindle according to claim 2, characterized in that: The stator mounting seat, the first air-floating bearing seat and the second air-floating bearing seat form an outer circumferential surface extending continuously along the axial direction inside the inner hole of the body body, and the outer circumferential surface is in contact with the inner wall of the inner hole of the body body. The outer circumferential surfaces of the stator mounting seat, the first air-floating bearing seat and the second air-floating bearing seat are provided with a cooling liquid groove extending continuously as a whole.

4. The electric spindle according to claim 3, characterized in that: The cooling liquid groove comprises a spiral groove, and the spiral groove comprises an inlet cooling liquid groove and a return cooling liquid groove, the inlet cooling liquid groove extends from the first end of the body outer shell to the second end direction, and the return cooling liquid groove extends from the second end of the body outer shell to the first end direction, the stator mounting seat is provided with a cooling liquid inlet connected to the inlet cooling liquid groove, and the stator mounting seat is provided with a cooling liquid outlet connected to the return cooling liquid groove.

5. The electric spindle according to claim 2, characterized in that: The first end of the first air-floating bearing seat has a first boss extending axially, and the first air-floating bearing seat is provided with a first axial step surface on the outer side of the first boss. The stator mounting seat has a first sleeve portion extending axially, the first sleeve portion is sleeved on the first boss, and the end of the first sleeve portion abuts against the first axial step surface. A first sealing ring is provided between the first air-floating bearing seat and the stator mounting seat. The second end of the first air-floating bearing seat has a second boss extending axially, the first air-floating bearing seat is provided with a second axial step surface on the outer side of the second boss, the second air-floating bearing seat has a second sleeve portion extending axially, the second sleeve portion is sleeved on the second boss, and the end of the second sleeve portion abuts against the second axial step surface, and a second sealing ring is provided between the first air-floating bearing seat and the second air-floating bearing seat.

6. The electric spindle according to claim 2, characterized in that: The first air bearing seat and the second air bearing seat are provided with honeycomb-shaped axial heat dissipation holes.

7. The electric spindle according to claim 2, characterized in that: The first thrust bearing assembly and the second thrust bearing assembly each include a first thrust bearing annular component and a second thrust bearing annular component, wherein the first thrust bearing annular component and the second thrust bearing annular component form a flush axial thrust surface, and a throttling gap is formed between the first thrust bearing annular component and the second thrust bearing annular component on the axial thrust surface for ejecting thrust airflow.

8. The electric spindle according to claim 7, characterized in that: The first radial air bearing is interference-fitted in the first air bearing seat and then integrally processed to form an axial hole for mounting the shaft core. The second radial air bearing is interference-fitted in the second air bearing seat and then integrally processed to form an axial hole for mounting the shaft core. The first thrust bearing annular component and the second thrust bearing annular component are installed in the first air bearing seat and the second air bearing seat and then integrally processed to form a flush axial thrust surface.

9. The electric spindle according to claim 2, characterized in that: The rear end of the stator mounting seat is provided with a concave cavity extending forward in the axial direction, the first driving cylinder includes a first cylinder head arranged in the concave cavity, the first cylinder head defines a first piston cavity inside the concave cavity, the piston of the first driving cylinder is arranged in the first piston cavity, the front end of the axial connecting rod is connected to the piston of the first driving cylinder, the rear end of the axial connecting rod passes through the first cylinder head and extends toward the second driving cylinder, the second driving cylinder includes a cylinder body and a second cylinder head, the cylinder body is connected to the rear end of the concave cavity, the cylinder body is provided with a second piston cavity, the piston of the second driving cylinder is arranged in the second piston cavity, and the piston of the second driving cylinder is provided with a push rod extending toward the axial connecting rod through the second cylinder head.

10. The electric spindle according to claim 1, characterized in that: A tool handle mounting hole is provided at the front end of the inner hole of the shaft core, and the claw assembly also includes a claw fixing ring, an elastic component, a gasket and multiple claw components. The claw fixing ring is installed in the inner hole of the shaft core, and the claw fixing ring is provided with multiple claw mounting grooves along the circumferential direction. Multiple claw components are inserted into the claw mounting grooves, and the front end of the sliding core is inserted into the claw fixing ring, the gasket is arranged on the rear side of the claw component, the elastic component is sleeved on the sliding core and presses against the gasket from the rear side, and the sliding core is provided with an avoidance groove cooperating with the claw.

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