阅读说明：本技术 一种电主轴和钻机 (Electric main shaft and drilling machine ) 是由 张翰乾 黄敏强 程振涛 汤丽君 汤秀清 于 2021-02-25 设计创作，主要内容包括：本发明公开了一种电主轴和钻机,包括：机体组件,包括铝合金机体和钢套,所述钢套套设于所述铝合金机体外部,并与所述铝合金机体形成一个整体,所述铝合金机体设有轴向孔；轴芯组件,设置于所述轴向孔,并通过上轴承组件和下轴承组件支承于所述铝合金机体；电机组件,用于驱动所述轴芯组件旋转；其中,所述上轴承组件包括上轴承座和上轴承,所述下轴承组件包括下轴承座和下轴承,所述上轴承座和/或下轴承座与所述铝合金机体一体制作。其降低了主轴自身重量,提高了钻孔效率的,又增强了主轴整体刚度,消除了装配误差,保证主轴垂直度。(The invention discloses an electric main shaft and a drilling machine, comprising: the engine body assembly comprises an aluminum alloy engine body and a steel sleeve, the steel sleeve is sleeved outside the aluminum alloy engine body and forms a whole with the aluminum alloy engine body, and the aluminum alloy engine body is provided with an axial hole; the shaft core assembly is arranged in the axial hole and is supported on the aluminum alloy machine body through an upper bearing assembly and a lower bearing assembly; the motor assembly is used for driving the shaft core assembly to rotate; the upper bearing assembly comprises an upper bearing seat and an upper bearing, the lower bearing assembly comprises a lower bearing seat and a lower bearing, and the upper bearing seat and/or the lower bearing seat and the aluminum alloy machine body are manufactured integrally. The self weight of the main shaft is reduced, the drilling efficiency is improved, the integral rigidity of the main shaft is enhanced, the assembly error is eliminated, and the verticality of the main shaft is ensured.)

1. An electric spindle, comprising:

the engine body assembly comprises an aluminum alloy engine body and a steel sleeve, the steel sleeve is sleeved outside the aluminum alloy engine body and forms a whole with the aluminum alloy engine body, and the aluminum alloy engine body is provided with an axial hole;

the shaft core assembly is arranged in the axial hole and is supported on the aluminum alloy machine body through an upper bearing assembly and a lower bearing assembly;

the motor assembly is used for driving the shaft core assembly to rotate;

the upper bearing assembly comprises an upper bearing seat and an upper bearing, the lower bearing assembly comprises a lower bearing seat and a lower bearing, and the upper bearing seat and/or the lower bearing seat and the aluminum alloy machine body are manufactured integrally.

2. The electric spindle according to claim 1, wherein the aluminum alloy housing is provided with an annular boss inside the axial hole, the annular boss forms the upper bearing seat, the lower bearing seat is detachably disposed on the housing assembly, the lower bearing seat is located below the upper bearing seat, a space is left between the upper bearing seat and the lower bearing seat, the motor assembly is disposed in the space, the motor assembly includes a stator and a rotor, the stator is fixedly connected to the aluminum alloy housing, and the rotor is fixedly connected to the shaft core assembly.

3. The motorized spindle of claim 2, wherein the upper bearing is an upper air bearing, the lower bearing is a lower air bearing, the spindle core assembly is provided with a flying disc, the body assembly is provided with a thrust air bearing assembly that cooperates with the flying disc, and the body assembly is provided with an air passage that communicates with the upper air bearing, the lower air bearing and the thrust air bearing assembly.

4. The electric spindle according to claim 3, wherein the annular boss is provided with a bearing installation cavity, and the upper air bearing is installed in the bearing installation cavity and locked by a bearing pressure plate.

5. The electric spindle according to claim 3, wherein the flying disc is disposed at a lower end of the spindle core assembly, a lower end of the steel sleeve protrudes out of the aluminum alloy machine body, a mounting groove is formed in the steel sleeve below the aluminum alloy machine body, and the thrust air bearing assembly is mounted in the mounting groove and is abutted against the aluminum alloy machine body above and the steel sleeve outside the aluminum alloy machine body.

6. The electric spindle according to claim 3, further comprising:

a cooling medium flow passage for cooling the upper bearing assembly and/or the lower bearing assembly and/or the thrust air bearing assembly and/or the motor assembly.

7. The electric spindle according to claim 1, wherein the spindle assembly comprises a spindle and a broach assembly disposed at a lower end of the spindle, and a unclamping cylinder is disposed at an upper end of the machine body assembly.

8. The electric spindle according to claim 2, wherein the stator has a first winding and a second winding, and further comprises a first contactor, a second contactor, and a frequency converter, the first winding is connected to the frequency converter, the second winding is externally connected to a first circuit and a second circuit, the first circuit short-circuits a power line of the second winding, the second circuit connects the second winding to the frequency converter, the first contactor is disposed in the first circuit, and the second contactor is disposed in the second circuit.

9. The electric spindle according to claim 8, further comprising:

a machine tool control end;

the first output circuit is used for transmitting an output signal of the machine tool control end to the first contactor;

the first feedback circuit is used for feeding back a state signal of the second contactor to the machine tool control end;

the second output circuit is used for transmitting an output signal of the machine tool control end to the second contactor;

the second feedback circuit is used for feeding back the state signal of the first contactor to the machine tool control end;

the control circuit is used for outputting a control signal to the frequency converter after the machine tool control end receives the state signal of the first feedback circuit or the second feedback circuit;

an auxiliary circuit for the first contactor and the second contactor to form an interlock.

10. A drilling machine comprising an electric spindle according to any one of claims 1 to 9.

Technical Field

The invention is used in the field of working spindles, and particularly relates to an electric spindle and a drilling machine.

Background

With the economic development and the technology, PCB drilling machines with higher processing efficiency are developed, the moving acceleration of a Z-axis system of the PCB drilling machines on the market exceeds 3G, the theoretical drilling number of the self Z-axis system structure of the drilling machine reaches 800 holes/min after the Z-axis system structure is optimized in a limit mode, but the problem that the weight of a main shaft cannot be reduced is faced (the larger the weight of the main shaft is, the larger the inertia is, the lower the limit processing efficiency of the PCB drilling machine is), and the processing efficiency of the PCB drilling machines is seriously reduced.

With the miniaturization of electronic components and the increasing complexity of functions of various electrical appliances, the integration level of the PCB is higher and higher, and the micro holes (phi 0.05-phi 0.2mm) on the PCB are more and more dense. The PCB is made of various materials (such as epoxy resin, copper foil and the like) with different thermal expansion coefficients, so that the difficulty of drilling is greatly increased. The quality of hole processing, particularly the roughness of the hole wall, is directly related to the quality of subsequent copper deposition and electroplating, and the reliability and the service life of electronic products. Particularly, in the case of continuous drilling, the high-speed friction between the drill and the hole wall raises the cutting temperature, and the resin of the circuit board is melted, and the circuit board is stained. In order to improve the drilling efficiency of dense holes and the drilling quality of micro holes, the problems can be solved only by adopting ultra-high-speed drilling.

In addition, during the process of drilling the small hole at the ultrahigh speed, the phenomenon of breaking the drill point often occurs, wherein one of the main reasons is that the verticality of the electric spindle is poor, and the drill point can not be guaranteed to drill the PCB in a vertical mode during the process of drilling the small hole at the high speed.

Disclosure of Invention

The invention aims to at least solve one of the technical problems in the prior art, and provides an electric main shaft and a drilling machine, which reduce the weight of the main shaft, improve the drilling efficiency, enhance the integral rigidity of the main shaft, eliminate assembly errors and ensure the verticality of the main shaft.

The technical scheme adopted by the invention for solving the technical problems is as follows:

in a first aspect, an electric spindle comprises:

the engine body assembly comprises an aluminum alloy engine body and a steel sleeve, the steel sleeve is sleeved outside the aluminum alloy engine body and forms a whole with the aluminum alloy engine body, and the aluminum alloy engine body is provided with an axial hole;

the shaft core assembly is arranged in the axial hole and is supported on the aluminum alloy machine body through an upper bearing assembly and a lower bearing assembly;

the motor assembly is used for driving the shaft core assembly to rotate;

the upper bearing assembly comprises an upper bearing seat and an upper bearing, the lower bearing assembly comprises a lower bearing seat and a lower bearing, and the upper bearing seat and/or the lower bearing seat and the aluminum alloy machine body are manufactured integrally.

With reference to the first aspect, in certain implementation manners of the first aspect, an annular boss is disposed inside the axial hole of the aluminum alloy machine body, the annular boss forms the upper bearing seat, the lower bearing seat is detachably disposed on the machine body assembly, the lower bearing seat is located below the upper bearing seat, a space is left between the upper bearing seat and the lower bearing seat, the motor assembly is disposed in the space, the motor assembly includes a stator and a rotor, the stator is fixedly connected to the aluminum alloy machine body, and the rotor is fixedly connected to the shaft core assembly.

With reference to the first aspect and the foregoing implementation manners, in some implementation manners of the first aspect, the upper bearing is an upper air bearing, the lower bearing is a lower air bearing, the shaft core assembly is provided with a flying disc, the machine body assembly is provided with a thrust air bearing assembly matched with the flying disc, and the machine body assembly is provided with an air passage communicated with the upper air bearing, the lower air bearing and the thrust air bearing assembly.

With reference to the first aspect and the foregoing implementation manners, in some implementation manners of the first aspect, the annular boss is provided with a bearing installation cavity, and the upper air bearing is installed in the bearing installation cavity and locked by the bearing pressing plate.

With reference to the first aspect and the foregoing implementation manners, in some implementation manners of the first aspect, the flying disc is disposed at the lower end of the shaft core assembly, the lower end of the steel sleeve protrudes out of the aluminum alloy machine body, an installation groove is formed in the steel sleeve below the aluminum alloy machine body, and the thrust air bearing assembly is installed in the installation groove and is respectively abutted to the aluminum alloy machine body above and the steel sleeve outside the aluminum alloy machine body.

With reference to the first aspect and the foregoing implementation manners, in some implementation manners of the first aspect, the method further includes:

a cooling medium flow passage for cooling the upper bearing assembly and/or the lower bearing assembly and/or the thrust air bearing assembly and/or the motor assembly.

With reference to the first aspect and the foregoing implementation manners, in some implementation manners of the first aspect, the shaft core assembly includes a shaft core and a broach assembly disposed at a lower end of the shaft core, and a unclamping cylinder is disposed at an upper end of the machine body assembly.

With reference to the first aspect and the foregoing implementation manners, in some implementation manners of the first aspect, the stator has a first winding and a second winding, and further includes a first contactor, a second contactor, and a frequency converter, where the first winding is connected to the frequency converter, the second winding is externally connected to a first circuit and a second circuit, the first circuit short-circuits a power line of the second winding, the second circuit connects the second winding to the frequency converter, the first contactor is disposed in the first circuit, and the second contactor is disposed in the second circuit.

With reference to the first aspect and the foregoing implementation manners, in some implementation manners of the first aspect, the method further includes:

a machine tool control end;

the first output circuit is used for transmitting an output signal of the machine tool control end to the first contactor;

the first feedback circuit is used for feeding back a state signal of the second contactor to the machine tool control end;

the second output circuit is used for transmitting an output signal of the machine tool control end to the second contactor;

the second feedback circuit is used for feeding back the state signal of the first contactor to the machine tool control end;

the control circuit is used for outputting a control signal to the frequency converter after the machine tool control end receives the state signal of the first feedback circuit or the second feedback circuit;

an auxiliary circuit for the first contactor and the second contactor to form an interlock.

In a second aspect, a drilling machine comprises the electric spindle of any one of the implementations of the first aspect.

One of the above technical solutions has at least one of the following advantages or beneficial effects:

the invention adopts the aluminum alloy machine body made of low-density materials and the high-rigidity steel sleeve to form the machine body assembly in a sleeved mode, thereby not only reducing the weight of the main shaft, but also ensuring the integral rigidity of the main shaft and improving the drilling efficiency.

Meanwhile, the upper bearing seat and/or the lower bearing seat and the aluminum alloy machine body are integrally manufactured and integrated with the machine body, so that the assembly error of the conventional bearing seat as an independent part is eliminated, the verticality of the main shaft is ensured, the verticality of a drill point in the high-speed drilling process is effectively ensured, and the phenomenon of breakage of the drill point is avoided.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic structural diagram of an electric spindle according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the body assembly of FIG. 1 in accordance with one embodiment;

FIG. 3 is a schematic view of the upper bearing assembly construction of one embodiment shown in FIG. 1;

FIG. 4 is a schematic view of a stator structure of one embodiment shown in FIG. 1;

FIG. 5 is a cross-sectional view of the bearing housing of the embodiment of FIG. 1;

FIG. 6 is a schematic cross-sectional view of an embodiment of the aluminum water jacket shown in FIG. 1;

FIG. 7 is a schematic diagram of the embodiment of FIG. 1 with the second winding shorted;

FIG. 8 is a schematic diagram of the second winding of the embodiment shown in FIG. 1 when connected to a frequency converter;

fig. 9 is a schematic circuit diagram of one embodiment shown in fig. 1.

Detailed Description

Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

In the present invention, if directions (up, down, left, right, front, and rear) are described, it is only for convenience of describing the technical solution of the present invention, and it is not intended or implied that the technical features referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, it is not to be construed as limiting the present invention.

In the invention, the meaning of "a plurality" is one or more, the meaning of "a plurality" is more than two, and the terms of "more than", "less than", "more than" and the like are understood to exclude the number; the terms "above", "below", "within" and the like are understood to include the instant numbers. In the description of the present invention, if there is description of "first" and "second" only for the purpose of distinguishing technical features, it is not to be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the precedence of the indicated technical features.

In the present invention, unless otherwise specifically limited, the terms "disposed," "mounted," "connected," and the like are to be understood in a broad sense, and for example, may be directly connected or indirectly connected through an intermediate; can be fixedly connected, can also be detachably connected and can also be integrally formed; may be mechanically coupled, may be electrically coupled or may be capable of communicating with each other; either as communication within the two elements or as an interactive relationship of the two elements. The specific meaning of the above-mentioned words in the present invention can be reasonably determined by those skilled in the art in combination with the detailed contents of the technical solutions.

Fig. 1 shows a reference direction coordinate system of an embodiment of the present invention, and the following describes an embodiment of the present invention with reference to the directions shown in fig. 1.

Referring to fig. 1, an embodiment of the present invention provides an electric spindle, which includes a machine body assembly 1, a shaft core assembly 2 and a motor assembly 3.

Because of the same volume, the lower the material density and the smaller the mass, most of the electric main shafts in the prior art are steel machine bodies, and the self weight of the main shaft is too large. Referring to fig. 1 and 2, a machine body assembly 1 according to an embodiment of the present invention includes an aluminum alloy machine body 11 and a steel jacket 12, a cylindrical surface is formed at an outer periphery of the aluminum alloy machine body 11, the steel jacket 12 is cylindrical, the steel jacket 12 is sleeved outside the aluminum alloy machine body 11 and forms a whole with the aluminum alloy machine body 11, and the aluminum alloy machine body 11 is provided with an axial hole for installing the machine body assembly 2. According to the embodiment of the invention, the aluminum alloy machine body 11 made of low-density materials and the high-rigidity steel sleeve 12 are sleeved to form the machine body assembly 1, so that the weight of the main shaft is reduced, the integral rigidity of the main shaft is ensured, and the drilling efficiency is improved.

The aluminum alloy body 11 and the steel sleeve 12 can be connected into a whole by adopting interference fit, threaded connection and other modes, and relative fixation is realized. For example, in the embodiment shown in fig. 2, the outer part of the aluminum alloy machine body 11 is protected by the steel jacket 12, the outer steel jacket 12 is fixed with the aluminum alloy machine body 11 through the upper and lower positioning pins 13 to form the machine body assembly 1, and the structural design achieves the purposes of reducing the weight of the main shaft and enhancing the overall rigidity of the main shaft. Meanwhile, the aluminum alloy body 11 and the steel sleeve 12 are fixed through the pin 13, so that the relative position accuracy of the aluminum alloy body 11 and the steel sleeve 12 is further guaranteed, and the aluminum alloy body 11 and the steel sleeve 12 are more convenient to assemble.

Referring to fig. 1, the spindle assembly 2 is disposed in the axial bore and supported to an aluminum alloy housing 11 by an upper bearing assembly 4 and a lower bearing assembly 5. Motor element 3 is located organism 1 middle part or afterbody, and motor element 3 is used for driving axle core subassembly 2 rotatory. The shaft core component 2 further drives cutters such as a drill bit and the like to rotate under the driving of the motor component 3, and machining is achieved.

In actual processing, a Z-axis system of the drilling machine clamps and clamps a main shaft to drill vertically downwards, and if the main shaft is poor in self verticality, a drill point is easy to incline and break. Referring to fig. 1, in the embodiment of the present invention, the upper bearing assembly 4 includes an upper bearing housing 41 and an upper bearing 42, the lower bearing assembly 5 includes a lower bearing housing 51 and a lower bearing 52, and the upper bearing housing 41 and/or the lower bearing housing 51 are integrally manufactured with the aluminum alloy housing 11. The upper bearing seat 41 and/or the lower bearing seat 51 are integrally manufactured with the aluminum alloy machine body 11 and integrated with the machine body, so that the assembly error of the conventional bearing seat as an independent part is eliminated, the verticality of a main shaft is ensured, the verticality of a drill point in the high-speed drilling process is effectively ensured, and the phenomenon of breakage of the drill point is avoided.

In some embodiments, referring to fig. 1, 2, the aluminum alloy body 11 is provided with an annular boss inside the axial hole, where the bore diameter of the axial hole is reduced, the annular boss forming the upper bearing seat 41. The lower bearing seat 51 is detachably disposed on the machine body assembly 1, and the lower bearing seat 51 is located below the upper bearing seat 41. That is, in this embodiment, the upper bearing seat 41 and the aluminum alloy housing 11 are integrally manufactured, the lower bearing seat 51 and the housing assembly 1 adopt a split structure, and the lower bearing seat 51 is detachably disposed on the housing assembly 1. In the embodiment, the upper bearing seat 41 and the aluminum alloy machine body 11 are integrally manufactured and integrated with the machine body, so that the assembly error of the conventional bearing seat as an independent part is eliminated, and the verticality of the main shaft is ensured.

Further, referring to fig. 1, a space is left between the upper bearing housing 41 and the lower bearing housing 51, the upper bearing housing 41 and the lower bearing housing 51 are spaced apart in the axial direction by a certain distance, the motor assembly 3 is disposed in the space, the motor assembly 3 includes a stator 31 and a rotor 32, the stator 31 is fixedly connected to the aluminum alloy housing 11, and the rotor 32 is fixedly connected to the shaft core assembly 2. The detachable lower bearing seat 51 facilitates the installation and adjustment of the shaft core assembly 2 and the motor assembly 3. Meanwhile, the motor assembly 3 adopts a middle-arranged structure, and the processing requirement of high-speed drilling can be met.

The upper bearing 42 and the lower bearing 52 may be rolling bearings or air bearings, for example, in the embodiment shown in fig. 1, the upper bearing 42 is an upper air bearing, and the lower bearing 52 is a lower air bearing. In order to bear the axial force of the shaft core assembly, the shaft core assembly 2 is provided with a flying disc 21, the machine body assembly 1 is provided with a thrust air bearing assembly 6 matched with the flying disc 21, and the machine body assembly 1 is provided with an air passage 14 communicated with an upper air bearing, a lower air bearing and the thrust air bearing assembly 6. Through external air supply, a pressure air film is formed among the shaft core assembly 2, the upper air bearing, the lower air bearing and the thrust air bearing assembly 6, the supporting shaft core assembly 2 is in a suspension state, and the stator 31 drives the shaft core assembly 2 to rotate at a high speed.

Further, referring to fig. 2 and 3, the annular boss is provided with a bearing installation cavity 43, the upper air bearing is installed in the bearing installation cavity 43, the air passage 14 of the body assembly 1 is directly connected to the bearing installation cavity 43, the upper end of the upper air bearing is abutted to the top edge of the bearing installation cavity 43, and the lower end of the upper air bearing is locked by a bearing pressing plate 44. The upper bearing seat 41 and the machine body assembly 1 are integrally manufactured, so that the assembly error of the conventional air-floating main shaft bearing seat as an independent part is eliminated, and the verticality of the main shaft is ensured.

The flying disc 21 can be disposed in the middle, upper end or lower end of the core assembly 2, for example, in the embodiment shown in fig. 1, the flying disc 21 is disposed at the lower end of the core assembly 2, and the air thrust bearing assembly 6 is correspondingly disposed at the lower end of the machine body assembly 1, such that the air thrust bearing assembly 6 and the flying disc 21 can be disposed closer to the output end of the core assembly 2, and the influence of the axial floating of the air thrust bearing assembly 6 on the rotation precision of the core assembly 2 is reduced.

Further, referring to fig. 1, the lower end of the steel sleeve 12 protrudes out of the aluminum alloy body 11, the axial dimension of the steel sleeve 12 is longer than that of the aluminum alloy body 11, the steel sleeve 12 and the aluminum alloy body 11 form a stepped structure, an installation groove 15 is formed below the aluminum alloy body 11 inside the steel sleeve 12, the thrust air bearing assembly 6 is installed in the installation groove 15 and is respectively abutted against the aluminum alloy body 11 above and the steel sleeve 12 outside, that is, the installation and positioning of the thrust air bearing assembly 6 on the body assembly 1 are realized through the stepped structure formed by the steel sleeve 12 and the aluminum alloy body 11, and the lower port of the body assembly 1 is closed.

Referring to fig. 1, the electric spindle further comprises a cooling medium flow channel and an aluminum water jacket 7, the aluminum water jacket 7 is arranged at the upper end of the machine body assembly 1, and the aluminum water jacket 7 is provided with a gas interface and a cooling liquid interface. The cooling medium flow channel is used for cooling the upper bearing assembly 4 and/or the lower bearing assembly 5 and/or the thrust air bearing assembly 6 and/or the motor assembly 3. In operation, the cooling liquid cools the lower bearing assembly 5, the thrust bearing assembly, the upper bearing assembly 4 and the motor assembly 3 through the aluminum water jacket 7, the machine body assembly 1 and the thrust bearing assembly.

In some embodiments, the mandrel assembly 2 includes a mandrel 22 and a broach assembly 23 disposed at the lower end of the mandrel 22, and the upper end of the machine body assembly 1 is provided with a unclamping cylinder 8. And the spindle assembly 2 is subjected to tool beating through the tool beating cylinder 8, so that the spindle can realize automatic tool changing.

It can be understood that the shaft core assembly 2 can also realize the connection of the cutter and the shaft core 22 by clamping and the like, and ensure the cutter changing function.

In the prior art, a common air-floatation high-speed PCB drilling machine electric main shaft often cannot simultaneously take large holes and small holes into consideration, the main shaft capable of drilling the large holes cannot process the small holes (the main shaft cannot drill the small holes at a rotating speed), and the main shaft capable of drilling the small holes cannot drill the large holes (the low-speed power is low), so that the main shaft further faces great challenges of selection of a motor, an external wiring mode of the motor and the like besides the fact that the main shaft capable of drilling the small holes cannot reach high standard requirements due to the performances of an. In some embodiments, referring to fig. 4-8, the stator 31 has a first winding 33 and a second winding 34, i.e. the electric spindle employs a double winding motor. The first winding 33 has one set of power supply wires U, V, W, and the second winding 34 has another set of power supply wires X, Y, Z, which pass through the body stator wire passing hole 45 (see fig. 5), the aluminum water jacket power supply wire passing hole 71 (see fig. 6), and finally are led out through the power supply connector. Referring to fig. 7, the low-speed winding of the main shaft is connected by X, Y, Z short circuit, U, V, W is self-formed into three phases (the main shaft has large torque and is suitable for drilling large holes at low rotating speed). Referring to fig. 8, the high speed winding connection of the spindle is that U, V, W wires are respectively connected with Z, X, Y wires to form three phase wires (high speed spindle suitable for drilling micro-holes).

In practical application, the winding can be switched by changing the wiring mode, but the switching of the winding by manually switching the wiring mode wastes labor hour, and because the current output to the main shaft by the frequency converter is large (the instantaneous current can exceed 10A), the winding is not switched correctly, so that safety accidents are easily caused, therefore, a set of wiring scheme of the double-winding main shaft is designed in the embodiment of the invention: the automatic switching between the high-speed winding and the low-speed winding of the high-speed and low-speed air floatation main shafts is realized, referring to fig. 9, the electric main shaft further comprises a first contactor 81, a second contactor 82 and a frequency converter 83, the first winding 33 is connected with the frequency converter 83, the second winding 34 is externally connected with a first circuit 84 and a second circuit 85, the first circuit 84 short-circuits a power line of the second winding 34, the second circuit 85 connects the second winding 34 with the frequency converter 83, the first contactor 81 is arranged on the first circuit 84, and the second contactor 82 is arranged on the second circuit 85 and is respectively used for controlling the disconnection or connection of the first circuit 84 and the second circuit 85.

Further, referring to fig. 9, the electric spindle further includes a machine tool control end 86, a first output circuit 87, a first feedback circuit 88, a second output circuit 89, a second feedback circuit 810, a control circuit 811, and an auxiliary circuit 812. The first output circuit 87 is used for transmitting an output signal of the machine tool control end 86 to the first contactor 81, and the first feedback circuit 88 is used for feeding back a state signal of the second contactor 82 to the machine tool control end 86; the second output circuit 89 is used for transmitting the output signal of the machine tool control end 86 to the second contactor 82; the second feedback circuit 810 is used for feeding back the state signal of the first contactor 81 to the machine tool control end 86; the control circuit 811 is used for outputting a control signal to the frequency converter 83 after the machine tool control terminal 86 receives the state signal of the first feedback circuit 88 or the second feedback circuit 810. The machine tool control end 86 outputs a signal to control the first contactor 81 and the second contactor 82 to act, so that high-speed and low-speed winding switching of the air floatation spindle is realized (when the first contactor 81 is closed and the second contactor 82 is not closed, a spindle low-speed winding connection method is adopted, when the second contactor 82 is closed and the first contactor 81 is not closed, a spindle high-speed winding connection method is adopted), after the winding switching, a feedback signal is fed back to the machine tool control end 86 (receiving a feedback signal and judging the winding switching condition), so that the frequency converter 83 is controlled to drive the spindle to operate, if the winding switching (the high-speed winding and the low-speed winding are switched mutually) is realized, the machine tool control end 86 needs to control the frequency converter 83 to stop the spindle in advance, after the first contactor 81 and the second contactor 82 are correctly switched, the frequency converter 83 is controlled to drive the spindle to operate, arc generation caused by contactor switching during electrification is avoided, the motor windings are switched quickly and accurately. The method realizes the drilling of the ultra-large hole and the micro-small hole through one air-floating electric main shaft.

Wherein the auxiliary circuit 812 is used for the first contactor 81 and the second contactor 82 to form an interlock. Namely, the first contactor 81 and the second contactor 82 cannot be closed at the same time after being electrified, so that the short circuit of the line is avoided.

Embodiments of the present invention also provide a drilling machine, including an electric spindle in any of the above embodiments.

In the description herein, references to the description of the term "example," "an embodiment," or "some embodiments," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The invention is not limited to the above embodiments, and those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the invention, and such equivalent modifications or substitutions are included in the scope of the claims of the present application.