General-purpose spindles and CNC machining centers using them

Abstract

This invention relates to the field of electric spindle technology, and more particularly to a general-purpose spindle and a CNC machining center using the same, comprising: a sleeve and a stator disposed within the sleeve, a rotor disposed within the stator, a mandrel with a hollow cavity disposed through the rotor, and a tie rod that mates with the hollow cavity of the mandrel; wherein a cylinder assembly is provided at one axial end of the mandrel, the cylinder assembly comprising a cylinder barrel connected to the sleeve, a cylinder cover connected to the end of the cylinder barrel away from the sleeve, and a piston disposed within the cylinder barrel; one end of the tie rod extends into the cylinder barrel, and an upper air-blowing transition seat is provided at the end of the tie rod extending into the cylinder barrel, suitable for abutting against the piston, and a lower air-blowing transition seat is sleeved on the part of the tie rod away from the cylinder barrel; an air passage suitable for gas flow is formed between the upper air-blowing transition seat, the outer wall of the tie rod and the inner wall of the mandrel, and between the lower air-blowing transition seat; and an air inlet assembly for air to enter the cylinder barrel and an oil inlet assembly for oil to enter the cylinder barrel are provided on the cylinder cover.

Description

Technical Field

[0001] This invention relates to the field of electric spindle technology, and more particularly to a general-purpose spindle and a CNC machining center using the same. Background Technology

[0002] The continuous maturation of advanced manufacturing technologies has placed higher demands on CNC machining technology and higher performance indicators on machine tool structures. Mechanical products are becoming increasingly precise and complex, and ordinary machine tools or highly specialized automated machine tools can no longer meet these requirements. Machining centers, a new type of machine tool, have emerged to meet these demands. Machining centers have advantages such as strong adaptability, high machining accuracy, stable machining quality, and high production efficiency, and therefore their applications are becoming increasingly widespread. The spindle is one of the core components of a machining center. The spindle is a component that is relatively independent from the machine tool's transmission system and overall structure, and it can autonomously realize the functions of the machine tool spindle and spindle motor.

[0003] The spindle, as one of the core components of a machining center, is widely used in existing three-axis and five-axis machining centers. However, current machining centers lack versatility in spindle design; a spindle suitable for a three-axis machining center is generally not suitable for a five-axis machining center. Therefore, different machining centers require different spindles. For example, the high-load, high-rigidity permanent magnet synchronous electric spindle disclosed in CN110539006A uses a hydraulic cylinder with an oil port that is only suitable for three-axis machining centers, as the spindle can only be used in a vertical position. However, some five-axis machining centers require a vertical spindle, while others require a horizontal one. Therefore, a spindle that can only be used vertically cannot meet the needs of all five-axis machining centers.

[0004] Furthermore, a central air passage within the pull rod allows the tool holder to be blown outwards by the airflow during tool release, thus aiding in tool unloading. In this structure, the outer wall of the rotor has an annular "T"-shaped air passage. When the tool is released, the pull rod pushes the front connecting rod forward, aligning the central air passage with the hole in the rotor wall. The central air passage then enters the air passage on the rotor's outer wall and exits from the rotor's end face, simultaneously blowing air onto the tool holder flange and center, thus better cleaning the tool holder end face. In this case, if cooling is required during tool holder machining, coolant must be introduced into the central air passage to allow it to flow into the tool holder. To address this, a switching valve is needed to switch between coolant and gas supplied to the central air passage. Furthermore, if a tight seal cannot be maintained between the central air passage and the hole in the rotor wall during fluid flow, unexpected overflow may occur.

[0005] Therefore, in view of the problems existing in the use of the spindle in the existing technology, it is necessary to further optimize the structure of the spindle. Summary of the Invention

[0006] The first objective of this invention is to provide a universal spindle to solve the technical problem of optimizing its overall performance.

[0007] The second objective of this invention is to provide a CNC machining center to solve the technical problem of optimizing its overall performance.

[0008] The universal spindle of this invention is implemented as follows: A general-purpose spindle includes: a sleeve and a stator disposed within the sleeve, a rotor disposed within the stator, a mandrel with a hollow cavity disposed through the rotor, and a tie rod that mates with the hollow cavity of the mandrel; wherein A cylinder assembly is provided on one side end of the mandrel. The cylinder assembly includes a cylinder barrel connected to the sleeve, a cylinder cover connected to the end of the cylinder barrel away from the sleeve, and a piston disposed inside the cylinder barrel. The pull rod is adapted to slide along the axial direction of the mandrel; one end of the pull rod extends into the cylinder, and an upper air-blowing transition seat is provided at the end of the pull rod extending into the cylinder, suitable for abutting against the piston; a lower air-blowing transition seat is fitted on the part of the pull rod away from the cylinder; an air passage suitable for gas flow is formed between the upper air-blowing transition seat, the outer wall of the pull rod and the inner wall of the mandrel, and between the lower air-blowing transition seat; and The cylinder head is provided with an air inlet assembly for air to enter the cylinder and an oil inlet assembly for oil to enter the cylinder; the piston is provided with a central through hole connecting the air inlet assembly and the air passage; the air inlet assembly includes a first air inlet and a first oil inlet on the end face of the cylinder head along the rotor axis, and the oil inlet assembly includes a second air inlet and a second oil inlet on the side wall of the cylinder head perpendicular to the rotor axis.

[0009] In an optional embodiment of the present invention, an exhaust passage connected to an air passage is provided in the part of the mandrel away from the oil cylinder.

[0010] In an optional embodiment of the invention, the tie rod has a hollow liquid channel extending through it along the rotor axial direction; and The upper air-blowing transition seat is provided with a connecting pipe for connecting to the hollow liquid channel and for liquid passage; The cylinder head is also equipped with a connector that extends into the cylinder barrel for connection to a connecting pipe.

[0011] In an optional embodiment of the invention, a spring support is provided between the outer wall of the pull rod and the inner wall of the spindle; and The outer wall of the pull rod and the inner wall of the spindle are also provided with multiple support rings arranged at intervals along the rotor axis. Each support ring is provided with a through hole that runs along the rotor axis and is suitable for airflow.

[0012] In an optional embodiment of the invention, the piston includes a cylindrical portion adapted to abut against an upward-blowing transition seat, and an annular portion connected to one end of the cylindrical portion facing the cylinder head; wherein The annular portion is folded outwards towards the columnar portion to form the shape; An elastic support is provided between the cylinder barrel and the side of the annular portion facing away from the cylinder head.

[0013] In an optional embodiment of the present invention, an indicator is further provided on the side of the annular portion facing away from the cylinder head; The cylinder is provided with a proximity switch on its side wall for sensing the indicator.

[0014] In an optional embodiment of the invention, the upward air-blowing transition seat has a frustoconical structure; and The area of ​​the end of the upper air-blowing transition seat connected to the pull rod is smaller than the area of ​​the end face of the upper air-blowing transition seat that abuts against the piston. The cylinder is also equipped with a detection switch on its side wall for detecting the distance to the outer side wall of the upper air-blowing transition seat.

[0015] In an optional embodiment of the present invention, the rotor includes an outer casing and a rotor core disposed within the outer casing; wherein Both axial ends of the outer casing are annular closed ends that are fixed to the spindle, and at least one oil inlet is provided at one of the annular closed ends of the axial ends.

[0016] In an optional embodiment of the present invention, a lower bearing assembly is also connected between the end of the mandrel away from the oil cylinder and the sleeve; The lower bearing assembly includes a lower bearing housing and a lower bearing body that cooperate with each other; wherein A ring-shaped cooling water jacket is fitted into the lower bearing housing, and the cooling water jacket and the lower bearing housing enclose an annular cavity for accommodating cooling water.

[0017] The CNC machining center of this invention is implemented as follows: A CNC machining center includes: the general-purpose spindle.

[0018] By adopting the above technical solution, the present invention has the following beneficial effects: The universal spindle of the present invention and the CNC machining center using it are both arranged on two different end faces of the cylinder head for the air inlet group and oil inlet group. In this way, the entire spindle can be arranged vertically or horizontally during use, so it is applicable not only to three-axis machining centers but also to five-axis machining centers, thereby improving the versatility of the spindle for three-axis and five-axis machining centers.

[0019] Furthermore, by forming air passages suitable for gas flow between the outer wall of the upper air-blowing transition seat and the outer wall of the pull rod and the inner wall of the mandrel, as well as between the lower air-blowing transition seat, a separate air passage suitable for ventilation is constructed inside the main shaft. This allows it to be distinguished from the liquid passage, thus meeting the needs of both ventilation and liquid flow without interference, making it flexible and reliable in use. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the universal spindle of the present invention; Figure 2 This is a partial structural diagram of the universal spindle of the present invention. Figure 1 ; Figure 3 This is a partial structural diagram of the universal spindle of the present invention. Figure 2 ; Figure 4 This is a partial structural diagram of the universal spindle of the present invention. Figure 3 ; Figure 5 This is a partial structural diagram of the universal spindle of the present invention. Figure 4 ; Figure 6 This is a partial structural diagram of the universal spindle of the present invention. Figure 5 ; Figure 7 This is a partial structural diagram of the universal spindle of the present invention. Figure 6 ; Figure 8 This is a schematic diagram of the rotor structure of the universal spindle of the present invention; Figure 9 This is a structural schematic diagram of the air inlet assembly and oil inlet assembly of the cylinder head of the universal spindle of the present invention; Figure 10 This is a schematic diagram of the structure of the tie rod of the universal spindle of the present invention; Figure 11 This is a schematic diagram of the piston structure of the universal spindle of the present invention; Figure 12 This is a schematic diagram of the cylinder head of the universal spindle of the present invention.

[0021] In the diagram: Sleeve 1, Stator 2, Rotor 3, Outer shell 31, Annular closed end 32, Oil inlet 33, Spindle 4, Tool holder tapered hole 41, Exhaust passage 42, Tie rod 5, Hollow liquid passage 51, Vent 52, Cylinder 6, Proximity switch 61, Detection switch 62, Airflow passage 63, Air storage chamber 64, Cylinder head 7, First air inlet 71, Second air inlet 72, First oil inlet 73, Second oil inlet 74, Columnar extension 76, Annular base 75, Gas... Flow channel 77, drain chamber 78, piston 8, columnar part 81, annular part 82, indicator 83, central through hole 85, code disk mounting seat 91, encoder code disk 92, upper air blowing transition seat 10, elastic support 110, lower bearing seat 121, lower bearing body 122, cooling water jacket 123, annular cavity 124, lower air blowing transition seat 130, spring support 140, support ring 141, connecting pipe 150, connector 151, upper bearing assembly 160. Detailed Implementation

[0022] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0023] Example 1: Please see Figures 1 to 12 As shown, this embodiment provides a general-purpose spindle, including: a sleeve 1 and a stator 2 disposed in the sleeve 1, a rotor 3 disposed in the stator 2, a mandrel 4 with a hollow cavity disposed through the rotor 3, and a tie rod 5 that cooperates with the hollow cavity of the mandrel 4; wherein the axial length of the mandrel 4 is greater than that of the rotor 3, so that the two axial ends of the mandrel 4 extend out of the outside of the rotor 3 respectively, and a reliable connection is formed between the mandrel 4 and the rotor 3, so that the rotor 3 can drive the mandrel 4 to rotate.

[0024] Based on the above, in order to allow the mandrel 4 to rotate relative to the sleeve 1, an upper bearing assembly 160 and a lower bearing assembly are respectively provided between the two ends of the mandrel 4 and the sleeve 1. Furthermore, a hydraulic cylinder assembly is provided at one axial end of the mandrel 4. This hydraulic cylinder assembly includes a cylinder 6 connected to the sleeve 1, a cylinder head 7 connected to the end of the cylinder 6 away from the sleeve 1, and a piston 8 disposed within the cylinder 6. The upper bearing assembly 160 is located at the end of the mandrel 4 facing the hydraulic cylinder assembly, while the lower bearing assembly is located at the end of the mandrel 4 away from the hydraulic cylinder.

[0025] Based on the above structure, it is necessary to add that the upper bearing assembly 160 in this embodiment is connected to the spindle 4 through the code disk mounting seat 91. The code disk mounting seat 91 is provided with an encoder code disk 92. This design is different from the traditional rear end nut design. The modified code disk mounting seat 91 and the spindle 4 can achieve precise positioning of the inner and outer holes, so that the encoder code disk 92 has higher installation accuracy.

[0026] Regarding the general-purpose spindle of this embodiment, it should also be noted that a cutter head assembly is installed at the end of the spindle 4 away from the oil cylinder. This cutter head assembly can be any mature method from the prior art, and its specific structure and implementation principle are not absolutely limited in this embodiment. For the cooperation between the spindle 4 and the cutter head assembly, a tapered hole 41 for the cutter shank is formed at the end of the spindle 4 away from the oil cylinder to achieve the purpose of air blowing through the tapered hole.

[0027] Next, it should be noted that the piston 8 includes a cylindrical portion 81 adapted to abut against the upper air-blowing transition seat 10, and an annular portion 82 connected to one end of the cylindrical portion 81 facing the cylinder head 7; wherein the annular portion 82 is folded outward from the cylindrical portion 81; and an elastic support member 110 is provided between the cylinder 6 and the side end of the annular portion 82 facing away from the cylinder head 7.

[0028] Based on the above structure, it should be noted that, optionally, an indicator 83 is also provided on the side of the annular portion 82 facing away from the cylinder head 7; a proximity switch 61 for sensing the indicator 83 is provided on the side wall of the cylinder barrel 6. Based on this structure, when the piston 8 returns to its highest position, the proximity switch 61 will not sense the indicator 83, thus outputting different signals to detect whether the piston 8 has returned to its original position. At this time, the upper air-blowing transition seat 10 disengages from the columnar portion 81 of the piston 8, allowing the spindle 4 to rotate, thereby protecting the hydraulic cylinder.

[0029] In one optional embodiment, the lower bearing assembly includes a lower bearing housing 121 and a lower bearing body 122 that cooperate with each other; wherein an annular cooling water jacket 123 is fitted into the lower bearing housing 121, and an annular cavity 124 for accommodating cooling water is formed between the cooling water jacket 123 and the lower bearing housing 121. Specifically, a sealing ring is provided between the cooling water jacket 123 and the lower bearing housing 121 to ensure that the cooling water in the cooling cavity does not overflow unexpectedly. For the annular cavity 124, an inlet channel and an outlet channel that cooperate with the cooling water jacket 123 are provided inside the lower bearing housing 121, and the lower bearing housing 121 has a cooling water inlet that communicates with the inlet channel and a cooling water outlet that communicates with the outlet channel. Here, the lower bearing housing 121 is designed to work with the cooling water jacket 123. The cooling water jacket 123 has a nearly complete water channel along its radial direction. Cooling water enters the water channel of the cooling water jacket 123 from the water inlet channel inside the lower bearing housing 121, circulates once, and flows out from the water outlet channel provided by the cooling water jacket 123, thus achieving the purpose of cooling the lower bearing housing 121 and the lower bearing body 122. In addition, due to the high-speed rotation of the spindle 4, the lower bearing body 122 may experience thermal expansion, causing the gap between the lower bearing body 122 and the inner hole of the lower bearing housing 121 to be filled. The cooling water passing through the annular cavity 124 formed by the cooling water jacket 123 and the lower bearing housing 121 to accommodate the cooling water maintains the small gap between the outer circle of the lower bearing body 122 and the inner hole of the lower bearing housing 121. The annular pressure of the cooling water in the annular cavity 124 also forms a self-aligning center, thereby increasing the service life of the lower bearing assembly and the accuracy of the spindle.

[0030] Furthermore, in this embodiment, the pull rod 5 is adapted to slide along the axial direction of the spindle 4; one end of the pull rod 5 extends into the cylinder 6, and an upper air-blowing transition seat 10 adapted to abut against the piston 8 is provided at the end of the pull rod 5 that extends into the cylinder 6; a lower air-blowing transition seat 130 is fitted on the part of the pull rod 5 away from the cylinder 6; an air passage suitable for gas flow is formed between the upper air-blowing transition seat 10, the outer wall of the pull rod 5 and the inner wall of the spindle 4, and the lower air-blowing transition seat 130. In order to meet the usage requirements of the air passage, an exhaust channel 42 connected to the air passage is provided in the part of the spindle 4 away from the oil cylinder.

[0031] When the general-purpose spindle of this embodiment releases the tool, the cylindrical part 81 of the piston 8 abuts against the upper air-blowing transition seat 10, thereby achieving a sealed fit between the piston 8 and the upper air-blowing transition seat 10. This allows the air blown into the cylinder head 7 of the hydraulic cylinder to pass smoothly through the circuit of the upper air-blowing transition seat 10 and the pull rod 5 into the hollow cavity of the spindle 4. The hollow cavity of the spindle 4 extends from the upper part of the spindle to the lower part of the spindle, allowing air to circulate to the lower part of the spindle 4, thereby entering the internal circuit of the lower air-blowing transition seat 130, and then entering the exhaust channel 42 of the spindle 4 through the circuit, thus reaching the tool holder taper hole 41, achieving the purpose of blowing air into the tool holder taper hole 41.

[0032] Based on the above, in one optional embodiment, the upper air-blowing transition seat 10 has a frustoconical structure; and the area of ​​the end of the upper air-blowing transition seat 10 connected to the pull rod 5 is smaller than the area of ​​the end face of the upper air-blowing transition seat 10 that abuts against the piston 8; a detection switch 62 for detecting the distance to the outer wall of the upper air-blowing transition seat 10 is also provided on the side wall of the cylinder 6. The pull rod 5 moves axially to achieve the switching of the tool release and pull state. When the spindle is in different tool release and pull states, the pull rod 5 is at different height positions, and the upper air-blowing transition seat 10 connected to it is also at different height positions in the spindle. Since its outer surface is a conical surface, the distance that the detection switch 62 can detect to the outer wall of the upper air-blowing transition seat 10 is different due to the movement of the pull rod 5, thereby outputting different signals. Based on the different output signals of the detection switch 62, it is determined whether the spindle is in the tool release, tool pull, or tool-free state, which helps to achieve accurate machining and operation.

[0033] A spring support 40 is provided between the outer wall of the pull rod 5 and the inner wall of the spindle 4; and multiple support rings are also provided between the outer wall of the pull rod 5 and the inner wall of the spindle 4, which are spaced apart along the axial direction of the rotor 3; each support ring is provided with a through hole that is suitable for airflow to pass through along the axial direction of the rotor 3.

[0034] The cylinder head 7 is provided with an air inlet assembly for air to be supplied into the cylinder 6 and an oil inlet assembly for oil to be supplied into the cylinder 6. The air inlet assembly includes a first air inlet 71 and a first oil inlet 73 located on the end face of the cylinder head 7 along the axial direction of the rotor 3. The oil inlet assembly includes a second air inlet 72 and a second oil inlet 74 located on the side wall of the cylinder head 7 perpendicular to the axial direction of the rotor 3.

[0035] It should be explained in detail here that the cylinder head 7 includes a columnar extension 76 for inserting into the columnar portion 81 of the piston 8 and an outwardly turned annular base portion 75 connected to one end of the columnar extension 76. The annular base portion 75 is adapted to cooperate with the annular portion 82 of the piston 8 and the inner wall of the cylinder 6 to form a cavity for receiving oil through the first oil inlet 73 or the second oil inlet 74. That is to say, the oil entering the cylinder 6 will not enter the columnar portion 81 of the piston 8. A sealing ring is provided between the outer wall of the columnar extension 76 and the inner wall of the columnar portion 81 to prevent oil from leaking into the upper air-blowing transition seat 10. The connector 151 is also sealed to the columnar extension 76 by a sealing ring to prevent liquid from leaking into the upper air-blowing transition seat 10.

[0036] The first air inlet 71, the first oil inlet 73, the second air inlet 72, and the second oil inlet 74 are all located on the annular base portion 75. A gas flow channel 77, which communicates with the first air inlet 71 and the second air inlet 72, is provided between the columnar extension portion 76 and the annular base portion 75. To accommodate the gas flow channel 77, the end of the columnar portion 81 of the piston 8 facing the upward blowing transition seat 10 has a central through hole 85 suitable for the connecting pipe 150 to pass through. The gas flowing in the gas flow channel 77 also enters the upward blowing transition seat 10 through this central through hole 85.

[0037] Therefore, in this embodiment, by designing the conformal fit between the columnar extension 76 of the cylinder head 7 and the columnar part 81 of the piston 8, the cylinder head 7 can meet the requirements for liquid and air passage without affecting the normal use of the oil cylinder. Furthermore, three different working cavities for liquid passage, oil passage, and air passage are formed in the cylinder barrel 6, which do not interfere with each other and are mutually sealed.

[0038] For the hydraulic cylinder in this embodiment, oil only needs to be introduced and discharged on the side of the piston 8 facing away from the rotor 3. When oil is introduced into the side of the piston 8 facing away from the rotor 3 through the first oil inlet 73 or the second oil inlet 74, the piston 8 moves towards the rotor 3. The elastic support member 110, such as multiple springs spaced apart along the circumferential direction, is compressed and deformed, so that the columnar part 81 of the piston 8 can abut against the upper air-blowing transition seat 10 and form a pushing force on the pull rod 5, thereby realizing the axial movement of the pull rod 5 in the spindle 4. The spring support member 140 is compressed and deformed. When the pull rod 5 needs to be reset, under the restoring action of the elastic support member 110, the oil on the piston 8 side will be discharged through the first oil inlet 73 or the second oil inlet 74, and the piston 8 will also release the pushing force on the pull rod 5, so that the pull rod 5 is reset under the restoring action of the spring support member 140. By adopting the above-described structure, the space inside the cylinder 6 facing the piston 8 towards the rotor 3 can form a space to accommodate the air-blowing transition seat 10, thereby facilitating the smooth use of the air passage and preventing interference with the oil in the cylinder.

[0039] Based on the above-mentioned hydraulic cylinder, it should also be noted that, in order to prevent the elastic support 110 from becoming less reliable due to fatigue during long-term use of the general-purpose spindle in this embodiment, thus failing to guarantee the stability of the piston 8's movement, the following design was also made in this embodiment: An airflow channel 63 for venting air into the cylinder 6 is provided on the side wall of the cylinder 6 corresponding to the annular portion 82 of the piston 8 facing away from the annular base portion 75. This airflow channel 63 connects the cylinder 6 and the air storage cavity 64 formed by the annular portion 82 of the piston 8 facing away from the annular base portion 75 (this air storage cavity 64 is also the cavity for accommodating the elastic support member 110). When the piston 8 moves towards the cylinder head 7, gas is introduced into the air storage cavity 64 through the airflow channel 63 to cooperate with the elastic support member 110, thereby improving the smoothness of the piston 8 moving towards the cylinder head 7. When the piston 8 needs to move towards the pull rod 5, the gas in the air storage cavity 64 is discharged to the outside of the cylinder 6 through the airflow channel 63, thereby reducing the gas resistance when the piston 8 moves towards the pull rod 5.

[0040] Furthermore, it should be noted that the pull rod 5 has a hollow liquid channel 51 that runs through the pull rod 5 along the axial direction of the rotor 3; and the upper air-blowing transition seat 10 has a connecting pipe 150 for connecting the hollow liquid channel 51 and for liquid flow; the cylinder head 7 is also equipped with a connector 151 that extends into the cylinder 6 for connecting to the connecting pipe 150. The connector 151 here is used for external pipeline so that liquid enters the connecting pipe 150 and the hollow liquid channel 51 of the pull rod 5 through the connector 151, and finally flows to the cutter head assembly.

[0041] Based on the above, it is necessary to explain that the end of the pull rod 5 connected to the upper air transition seat 10 is also provided with an axially extending vent 52 suitable for gas passage. This vent 52 is not connected to the hollow liquid channel 51. If the hollow liquid channel 51 is opened at the axis of the pull rod 5, then the vent 52 can be understood as being opened at a non-axial position of the pull rod 5.

[0042] Referring to the accompanying drawings, in one optional embodiment, a drain chamber 78 for discharging liquid is pre-installed in the cylinder head 7. The connector 151 passes through the drain chamber 78 and connects to the connecting pipe 150. The drain chamber 78 forms a sealed cavity through the fit between the cap and the cylinder head 7. A first drain port communicating with the drain chamber 78 is provided on the end face of the cylinder head 7 along the axial direction of the rotor 3, and a second drain port communicating with the drain chamber 78 is provided on the side wall of the cylinder head 7 perpendicular to the axial direction of the rotor 3. The design of the drain chamber 78, the first drain port, and the second drain port is primarily to discharge any liquid that may flow into the cylinder head 7 when the connector 151 is fitted with the cylinder head 7.

[0043] Regarding the rotor 3 used in this embodiment, referring to the accompanying drawings, an optional implementation is provided. The rotor 3 includes a housing 31 and a rotor core 3 disposed within the housing 31. Both axial ends of the housing 31 are annular closed ends 32 fixedly connected to the spindle 4, and at least one oil inlet 33 is provided at one of the annular closed ends 32. In this structure, oil pressure is introduced into the oil inlet 33, causing the inner cavity of the rotor 3 to expand, thus allowing it to fit snugly into the spindle 4. When the rotor 3 is installed in the designated position within the spindle 4, the oil supply is stopped, the inner cavity of the rotor 3 shrinks, and it is interference-fitted onto the outer circle of the spindle 4 through its own deformation. Furthermore, both the inner circle of the rotor 3 and the outer circle of the spindle 4 are tapered, thus achieving good axial self-centering.

[0044] In summary, for the general-purpose spindle of this embodiment, the air inlet group and oil inlet group provided on the cylinder head 7 are both located on two different end faces of the cylinder head 7, with corresponding first drain port and second drain port. Thus, the entire spindle can be arranged vertically or horizontally during use, making it suitable not only for three-axis machining centers but also for five-axis machining centers, thereby improving the versatility of the spindle for both three-axis and five-axis machining centers.

[0045] Furthermore, by forming air passages suitable for gas flow between the outer wall of the upper air transition seat 10 and the outer wall of the pull rod 5 and the inner wall of the spindle 4, and between the lower air transition seat 130, a separate air passage suitable for ventilation is constructed inside the main shaft, which can be distinguished from the liquid passage, thus meeting the needs of both ventilation and liquid passage without interference, making it flexible and reliable to use.

[0046] Example 2: Based on the general-purpose spindle of Embodiment 1, this embodiment provides a CNC machining center, including: the general-purpose spindle of Embodiment 1. The CNC machining center of this embodiment can be, for example, but not limited to, a three-axis machining center and / or a five-axis machining center. This embodiment does not absolutely limit the specific CNC machining center used in this embodiment.

[0047] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0048] In the description of this invention, it should be understood that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing the invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0049] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0050] In this invention, unless otherwise expressly specified and limited, "above or below" a first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

Claims

1. A universal spindle, characterized in that, include: A sleeve and a stator disposed within the sleeve, a rotor disposed within the stator, a hollow mandrel disposed through the rotor, and a tie rod that mates with the hollow cavity of the mandrel; wherein A cylinder assembly is provided on one side end of the mandrel. The cylinder assembly includes a cylinder barrel connected to the sleeve, a cylinder cover connected to the end of the cylinder barrel away from the sleeve, and a piston disposed inside the cylinder barrel. The pull rod is adapted to slide along the axial direction of the mandrel; one end of the pull rod extends into the cylinder, and an upper air-blowing transition seat is provided at the end of the pull rod extending into the cylinder, suitable for abutting against the piston; a lower air-blowing transition seat is fitted on the part of the pull rod away from the cylinder; an air passage suitable for gas flow is formed between the upper air-blowing transition seat, the outer wall of the pull rod and the inner wall of the mandrel, and between the lower air-blowing transition seat; and The cylinder head is provided with an air inlet assembly for air to enter the cylinder and an oil inlet assembly for oil to enter the cylinder; the piston is provided with a central through hole connecting the air inlet assembly and the air passage; the air inlet assembly includes a first air inlet and a first oil inlet on the end face of the cylinder head along the rotor axis, and the oil inlet assembly includes a second air inlet and a second oil inlet on the side wall of the cylinder head perpendicular to the rotor axis.

2. The universal spindle according to claim 1, characterized in that, The spindle is provided with an exhaust channel connected to the air passage in the part away from the oil cylinder.

3. The universal spindle according to claim 1 or 2, characterized in that, The tie rod has a hollow liquid channel that runs through it along the rotor axis; and The upper air-blowing transition seat is provided with a connecting pipe for connecting to the hollow liquid channel and for liquid passage; The cylinder head is also equipped with a connector that extends into the cylinder barrel for connection to a connecting pipe.

4. The universal spindle according to claim 1, characterized in that, A spring support is provided between the outer wall of the pull rod and the inner wall of the spindle; and The outer wall of the pull rod and the inner wall of the spindle are also provided with multiple support rings arranged at intervals along the rotor axis. Each support ring is provided with a through hole that runs along the rotor axis and is suitable for airflow.

5. The universal spindle according to claim 1, characterized in that, The piston includes a cylindrical portion adapted to abut against an upper air-blowing transition seat, and an annular portion connected to one end of the cylindrical portion facing the cylinder head; wherein The annular portion is folded outwards towards the columnar portion to form the shape; An elastic support is provided between the cylinder barrel and the side of the annular portion facing away from the cylinder head.

6. The universal spindle according to claim 5, characterized in that, An indicator is also provided on the side of the annular portion facing away from the cylinder head; The cylinder is provided with a proximity switch on its side wall for sensing the indicator.

7. The universal spindle according to claim 5, characterized in that, The upper air-blowing transition seat has a frustoconical structure; and The area of ​​the end of the upper air-blowing transition seat connected to the pull rod is smaller than the area of ​​the end face of the upper air-blowing transition seat that abuts against the piston. The cylinder is also equipped with a detection switch on its side wall for detecting the distance to the outer side wall of the upper air-blowing transition seat.

8. The universal spindle according to claim 1, characterized in that, The rotor includes an outer casing and a rotor core disposed within the outer casing; wherein Both axial ends of the outer casing are annular closed ends that are fixed to the spindle, and at least one oil inlet is provided at one of the annular closed ends of the axial ends.

9. The universal spindle according to claim 1, characterized in that, A lower bearing assembly is also connected between the end of the mandrel away from the oil cylinder and the sleeve. The lower bearing assembly includes a lower bearing housing and a lower bearing body that cooperate with each other; wherein A ring-shaped cooling water jacket is fitted into the lower bearing housing, and the cooling water jacket and the lower bearing housing enclose an annular cavity for accommodating cooling water.

10. A CNC machining center, characterized in that, include: The general-purpose spindle as described in any one of claims 1 to 9.

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