Electric spindle and machine tool

Abstract

The application provides an electric spindle and a machine tool, and belongs to the technical field of electric spindles. The electric spindle comprises a shaft core, the shaft core has a first end and a second end arranged oppositely in the axial direction of the shaft core, the second end of the shaft core is provided with a shaft core matching surface, the second end of the shaft core is used for connecting a tool shank, and the shaft core matching surface of the second end of the shaft core is used for matching a tool shank matching surface of the tool shank. The electric spindle has a clamped tool state when the shaft core matching surface and the tool shank matching surface are attached and a loosened tool state when the shaft core matching surface and the tool shank matching surface are separated. At least one shaft core cooling flow channel outlet is arranged on the shaft core cooling flow channel, and the outlet end of the at least one shaft core cooling flow channel outlet is open to the shaft core matching surface. In the application, the shaft core cooling flow channel is arranged on the shaft core matching surface of the electric spindle shaft core, which can realize the cooling of the spindle shaft core and the sealing of the front end of the electric spindle in the clamped tool state, and can realize the cleaning of the front end of the electric spindle in the loosened tool state.

Description

Technical Field

[0001] This invention relates to the field of electric spindle technology, and more particularly to an electric spindle and machine tool. Background Technology

[0002] In the field of high-speed and high-precision mold processing, some parts have high requirements for processing accuracy. However, during the high-speed rotation of the spindle, the heat generated by the bearing and motor parts is transferred to the spindle core, causing thermal deformation of the core and affecting the actual processing accuracy.

[0003] The processing environment for molds made of some special materials is extremely harsh. For example, when the spindle of a graphite machine processes a graphite mold, it generates a lot of dust. This dust can easily enter the spindle from the front end or adhere to the tapered hole surface of the tool holder, affecting the spindle's service life and processing performance. Summary of the Invention

[0004] To overcome the problems existing in related technologies, embodiments of the present invention propose an electric spindle and machine tool.

[0005] A first aspect of the present invention provides an electric spindle, comprising:

[0006] The shaft has a first end and a second end that are arranged opposite to each other in its axial direction. The second end of the shaft is provided with a shaft mating surface. The second end of the shaft is used to connect to the tool holder. The shaft mating surface of the second end of the shaft is used to mate with the tool holder mating surface of the tool holder.

[0007] The electric spindle has a clamping state when the spindle core mating surface and the tool holder mating surface are in contact, and a releasing state when the spindle core mating surface and the tool holder mating surface are separated.

[0008] The shaft core is provided with a shaft core cooling channel, and the shaft core cooling channel has at least one shaft core cooling channel outlet. The outlet end of the at least one shaft core cooling channel outlet opens at the shaft core mating surface.

[0009] In the above technical solution, the shaft core mating surface includes a first shaft core mating surface and a second shaft core mating surface, and the tool holder mating surface includes a first tool holder mating surface that mates with the first shaft core mating surface and a second tool holder mating surface that mates with the second shaft core mating surface.

[0010] The first shaft core mating surface is set perpendicular to the axis of the shaft core, and the first shaft core mating surface includes an inner end of the first shaft core mating surface close to the axis and an outer end of the first shaft core mating surface away from the axis.

[0011] The second shaft core mating surface is inclined to the axis of the shaft core, and the second shaft core mating surface includes an inner end of the second shaft core mating surface close to the axis and an outer end of the second shaft core mating surface away from the axis;

[0012] The outer end of the second shaft core mating surface is connected to the inner end of the first shaft core mating surface, and the outer end of the second shaft core mating surface is positioned closer to the center of the shaft core than the inner end of the second shaft core mating surface.

[0013] In the above technical solution, at least one shaft core cooling channel outlet includes a first shaft core cooling channel outlet that opens into a first shaft core mating surface and / or a second shaft core cooling channel outlet that opens into a second shaft core mating surface;

[0014] The outlet direction of the first shaft core cooling channel is perpendicular to the mating surface of the first tool holder, and the outlet direction of the second shaft core cooling channel forms an angle α with a range of 20° to 70° with the mating surface of the second tool holder.

[0015] In the above technical solution, the outlet position of the cooling channel outlet of the second shaft core is close to the inner end of the mating surface of the second shaft core.

[0016] In the above technical solution, the shaft core mating surface is inclined to the axis of the shaft core. The shaft core mating surface includes an inner end of the shaft core mating surface close to the axis of the shaft core and an outer end of the shaft core mating surface away from the axis of the shaft core. The outer end of the shaft core mating surface is located closer to the middle of the shaft core than the inner end of the shaft core mating surface.

[0017] At least one of the spindle cooling channel outlets includes a first spindle cooling channel outlet that opens into the spindle mating surface, wherein the outlet direction of the first spindle cooling channel outlet forms an angle α with the tool holder mating surface in the range of 20° to 70°.

[0018] In the above technical solution, at least one shaft core cooling channel outlet includes a third shaft core cooling channel outlet that opens onto the outer peripheral wall of the shaft core;

[0019] The electric spindle also includes a front flange sleeved on the outer peripheral wall of the spindle core and a gland for fixing the front flange. An air seal ring is provided between the front flange and the gland and the spindle core, and the air seal ring is clearance-fitted with the front flange and the gland.

[0020] The air sealing ring has air holes and air storage grooves, and the outlet of the cooling channel of the third shaft core is connected to the air holes.

[0021] In the above technical solution, at least a portion of the cooling channel of the shaft core is an axial groove formed on the outer peripheral wall of the shaft core;

[0022] The electric spindle also includes a motor rotor, which is sleeved on the outer peripheral wall of the spindle core and seals the axial groove.

[0023] In the above technical solution, the shaft core cooling channel includes a first shaft core cooling channel section, an axial groove, a second shaft core cooling channel section, and a third shaft core cooling channel section connected in sequence.

[0024] The first shaft core cooling channel section is inclined or perpendicular to the shaft core axis, the axial groove and the third shaft core cooling channel section are parallel to the shaft core axis, and the second shaft core cooling channel section is perpendicular to the shaft core axis.

[0025] In the above technical solution, the electric spindle also includes:

[0026] A pull rod assembly is located inside the shaft core and connected to the tool holder. The pull rod assembly has a first motion state that causes the tool holder mating surface to fit with the shaft core mating surface and a second motion state that causes the tool holder mating surface to separate from the shaft core mating surface.

[0027] The tie rod assembly is also equipped with a tie rod cooling channel, wherein the outlet of the tie rod cooling channel is designed such that when the tie rod assembly switches between the first motion state and the second motion state, the outlet of the tie rod cooling channel is always connected to the inlet of the shaft core cooling channel.

[0028] In the above technical solution, the tie rod assembly includes:

[0029] Pull rod body;

[0030] A front spacer and a middle spacer are fitted onto the outside of the tie rod body, with the front spacer positioned relative to the middle spacer at the second end of the shaft core, wherein the position of the front spacer relative to the shaft core is fixed.

[0031] The elastic element includes a first elastic element and a second elastic element. The first elastic element is disposed on the pull rod body and located between the front spacer and the middle spacer. The pull rod body is provided with a limiting surface. The second elastic element is disposed between the middle spacer and the limiting surface.

[0032] The tie rod cooling channel includes a first tie rod cooling channel section disposed on the tie rod body and a second tie rod cooling channel section disposed on the intermediate spacer and connected to the first tie rod cooling channel section, wherein the outlet of the second tie rod cooling channel section is connected to the inlet of the shaft core cooling channel.

[0033] In the above technical solution, the second tie rod cooling channel section includes a second tie rod cooling channel inlet section, a second tie rod cooling channel middle section, and a second tie rod cooling channel outlet section connected in sequence.

[0034] The air inlet section of the second tie rod cooling channel is connected to the air outlet section of the first tie rod cooling channel, and the air outlet section of the second tie rod cooling channel is connected to the shaft core cooling channel; wherein

[0035] The width of the air inlet of the second tie rod cooling channel in the direction of the shaft axis is greater than the width of the air outlet of the first tie rod cooling channel in the direction of the shaft axis.

[0036] The width of the air outlet of the second tie rod cooling channel outlet section in the direction of the shaft axis is greater than the width of the air inlet of the shaft cooling channel in the direction of the shaft axis.

[0037] In the above technical solution, the stiffness of the intermediate spacer is greater than the stiffness of the elastic element.

[0038] In the above technical solution, the shaft core cooling channel is provided in multiple sets, and the multiple sets of shaft core cooling channels are evenly distributed in the circumferential direction of the shaft core.

[0039] The tie rod cooling channels are provided in multiple sets, and these multiple sets of tie rod cooling channels are evenly distributed in the circumferential direction of the tie rod assembly; among them

[0040] Each set of shaft core cooling channels is connected to a set of tie rod cooling channels.

[0041] In the above technical solution, the pull rod body is also provided with a main channel, which is used to connect with multiple sets of pull rod cooling channels and to distribute the cooling medium in the main channel to multiple pull rod cooling channels.

[0042] In the above technical solution, the pull rod assembly also includes a pull claw structure, a pull rod connector, and a rotary joint;

[0043] The tie rod body has a tie rod head end and a tie rod tail end that are arranged opposite to each other in its axial direction;

[0044] The first end of the pull rod is connected to the tool holder via a pull claw structure, and the second end of the pull rod is connected to the rotary joint via a pull rod extension.

[0045] In the above technical solution, the electric spindle also includes a stator assembly, a front bearing, and a rear bearing;

[0046] The stator assembly is sleeved on the outside of the shaft core. One end of the stator is rotatably engaged with the second end of the shaft core through a front bearing, and the other end is rotatably engaged with the first end of the shaft core through a rear bearing.

[0047] A second aspect of the present invention provides a machine tool comprising the electric spindle described above.

[0048] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0049] I. In this embodiment of the invention, a spindle cooling channel is provided on the spindle core mating surface (which mates with the tool holder mating surface) of the electric spindle core. On the one hand, the spindle core is cooled and the front end of the electric spindle is sealed when the electric spindle is clamped. On the other hand, the front end of the electric spindle can be cleaned when the tool is released. Attached Figure Description

[0050] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0051] Figure 1 This is a schematic diagram of the main structure of an embodiment of the electric spindle of the present invention;

[0052] Figure 2 This is a schematic cross-sectional view of the first embodiment of the electric spindle of the present invention, in which the electric spindle is in a clamping state;

[0053] Figure 3 This is a schematic cross-sectional view of a second embodiment of the electric spindle of the present invention, in which the electric spindle is in a tool-released state;

[0054] Figure 4 This is a schematic diagram of a third cross-sectional structure of an embodiment of the electric spindle of the present invention. A stator assembly is fitted around the outside of the electric spindle in the figure.

[0055] Figure 5 for Figure 3 An enlarged structural diagram at point A in the embodiment;

[0056] Figure 6 for Figure 3 A magnified structural diagram at point B in the embodiment;

[0057] Figure 7 for Figure 3 An enlarged structural diagram at point C in the embodiment;

[0058] Figure 8 for Figure 2 An enlarged structural diagram of the second end of the shaft core in the embodiment;

[0059] Figure 9 This is a cross-sectional view of the gas sealing ring in an embodiment of the electric spindle of the present invention;

[0060] Figure 10 This is a cross-sectional view of the intermediate spacer in an embodiment of the electric spindle of the present invention.

[0061] Wherein: 1-shaft core; 11-shaft core mating surface; 111-first shaft core mating surface; 1111-first shaft core cooling channel outlet; 1121-second shaft core cooling channel outlet; 1131-third shaft core cooling channel outlet; 112-second shaft core mating surface; 12-first end; 13-second end; 14-shaft core cooling channel; 141-first shaft core cooling channel section; 142-axial groove; 143-second shaft core cooling channel section; 144-third shaft core cooling channel section; 2-tool holder; 21-tool holder mating surface; 3-front flange; 4-gland; 5-gas seal ring; 51-vent; 52-Air storage tank; 6-Motor rotor; 7-Tie rod assembly; 71-Tie rod cooling channel; 711-First tie rod cooling channel section; 712-Second tie rod cooling channel section; 7121-Inlet end of second tie rod cooling channel; 7122-Middle section of second tie rod cooling channel; 7123-Outlet section of second tie rod cooling channel; 72-Tie rod body; 73-Front spacer; 74-Middle spacer; 75-First elastic element; 76-Second elastic element; 77-Main channel; 78-Pulley structure; 79-Tie rod connector; 80-Rotary joint; 8-Stator assembly; 9-Front bearing; 10-Rear bearing; Detailed Implementation

[0062] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0063] Currently available electric spindles generate a large amount of dust when processing molds made of special materials, such as graphite molds. This dust easily enters the spindle from the front end (the second end) or adheres to the tapered hole surface of the tool holder, affecting the spindle's lifespan and machining performance. In this invention, a cooling channel is provided on the spindle core mating surface (which mates with the tool holder mating surface). This achieves cooling of the spindle core and sealing of the front end of the electric spindle when the tool is clamped, and also allows for cleaning of the front end of the electric spindle when the tool is released.

[0064] The following is in conjunction with the appendix Figure 1-10 The technical solution of this embodiment is described in detail. Unless otherwise specified, the following implementation methods and embodiments can be combined with each other.

[0065] Example 1

[0066] like Figure 1As shown, this embodiment proposes an electric spindle, comprising:

[0067] The shaft core 1 has a first end 12 and a second end 13 disposed opposite to each other in its axial direction. The second end 13 of the shaft core 1 is provided with a shaft core mating surface 11. The second end 13 of the shaft core 1 is used to connect to the tool holder 2. The shaft core mating surface 11 of the shaft core 1 is used to mate with the tool holder mating surface 21 of the tool holder 2.

[0068] The electric spindle has a clamping state when the spindle core mating surface 11 and the tool holder mating surface 21 are in contact, and a tool release state when the spindle core mating surface 11 and the tool holder mating surface 21 are separated.

[0069] The shaft core 1 is provided with a shaft core cooling channel 14, and the shaft core cooling channel 14 is provided with at least one shaft core cooling channel outlet, wherein the outlet end of at least one shaft core cooling channel outlet opens at the shaft core mating surface 11.

[0070] In this embodiment of the invention, a spindle cooling channel 14 is provided on the spindle core 11 mating surface 11 (which mates with the tool holder mating surface 21 of the tool holder 2). On the one hand, the spindle core 1 is cooled and the front end (i.e., the second end 13) of the spindle is sealed when the spindle is clamped. On the other hand, the front end (i.e., the second end 13) of the spindle is cleaned when the tool is released.

[0071] It is worth noting that the first end and the second end mentioned in the embodiments of the present invention should not be narrowly interpreted as two end faces that are set opposite each other. Instead, they refer to a relative relationship between the two sides of the shaft core 1 in the axial direction.

[0072] Specifically, such as Figure 5 As shown, the shaft core mating surface 11 includes a first shaft core mating surface 111 and a second shaft core mating surface 112, and the tool holder mating surface 21 includes a first tool holder mating surface 211 that mates with the first shaft core mating surface 111 and a second tool holder mating surface 212 that mates with the second shaft core mating surface 112.

[0073] like Figure 5 As shown, the first shaft core mating surface 111 is arranged perpendicular to the axis of the shaft core 1, wherein the first shaft core mating surface 111 includes an inner end of the first shaft core mating surface close to the axis of the shaft core 1 and an outer end of the first shaft core mating surface away from the axis of the shaft core 1.

[0074] The second shaft core mating surface 112 is inclined to the axis of the shaft core 1. The second shaft core mating surface includes an inner end of the second shaft core mating surface close to the axis of the shaft core 1 and an outer end of the second shaft core mating surface away from the axis of the shaft core 1.

[0075] The outer end of the second shaft core mating surface is connected to the inner end of the first shaft core mating surface, and the outer end of the second shaft core mating surface is located closer to the middle of the shaft core 1 relative to the inner end of the second shaft core mating surface. That is, the second shaft core mating surface 112 is an inclined surface facing the middle of the shaft core.

[0076] More specifically, such as Figure 5 As shown, at least one shaft cooling channel outlet includes a first shaft cooling channel outlet 1111 opening onto the first shaft mating surface 111 and / or a second shaft cooling channel outlet 1121 opening onto the second shaft mating surface 112; preferably, at least one shaft cooling channel outlet includes a first shaft cooling channel outlet 1111 opening onto the first shaft mating surface 111 and a second shaft cooling channel outlet 1121 opening onto the second shaft mating surface 112.

[0077] The outlet direction of the first shaft core cooling channel outlet 1111 is perpendicular to the first tool holder mating surface 211, and the outlet direction of the second shaft core cooling channel outlet 1121 forms an angle α with a range of 20° to 70° with the second tool holder mating surface.

[0078] When the electric spindle is in the tool release state, the first tool holder mating surface 211 of the tool holder 2 and the first shaft core mating surface 111 of the shaft core 1 are separated, forming a gap between them. The second tool holder mating surface 212 of the tool holder 2 and the second shaft core mating surface 112 of the shaft core 1 are also separated, forming a gap between them. At this time, by setting the first shaft core cooling channel outlet 1111 and the second shaft core mating surface 1112 on the first shaft core mating surface 111 and the second shaft core mating surface 1112 respectively, the compressed gas discharged through the first shaft core cooling channel outlet 1111 and the second shaft core cooling channel outlet 1112 can clean the impurities in the gap position.

[0079] When the electric spindle is in the clamped state, the first tool holder mating surface 211 of the tool holder 2 and the first shaft core mating surface 111 of the shaft core 1 are in contact, and the gap between them is eliminated. The second tool holder mating surface 121 of the tool holder 2 and the second shaft core mating surface 112 of the shaft core 1 are also in contact, and the gap between them is also eliminated. At this time, the motor rotor position and the front bearing position on the shaft core 1 can be cooled through the shaft core cooling channel 14 provided on the shaft core 1, reducing the thermal deformation of the shaft core caused by the heat generated by the motor and bearing during the actual operation of the electric spindle.

[0080] In summary, in this embodiment of the invention, by providing a cooling channel 14 on the spindle core 1 and injecting compressed gas into the cooling channel 14, the cooling effect and / or airtightness and / or cleaning effect of the electric spindle can be achieved, and the utilization rate of compressed gas is improved.

[0081] In any of the above embodiments, such as Figure 5As shown, at least one shaft core cooling channel outlet includes a first shaft core cooling channel outlet 1111 that opens into the first shaft core mating surface 111 and a second shaft core cooling channel outlet 1121 that opens into the second shaft core mating surface 112.

[0082] The outlet direction of the first shaft core cooling channel outlet 1111 is perpendicular to the first tool holder mating surface 211, and the outlet direction of the second shaft core cooling channel outlet 1121 forms an angle α with a range of 20° to 70° with the second tool holder mating surface 212.

[0083] In this embodiment of the invention, by setting the outlet direction of the cooling channel outlet 1121 of the second shaft core to form a certain angle with the mating surface 212 of the second tool holder, the cleaning effect on the impurities accumulated between the tool holder 2 and the shaft core 1 can be improved, and impurities can be avoided from accumulating between the tool holder 2 and the shaft core.

[0084] In any of the above embodiments, such as Figure 5 As shown, in order to further improve the cleaning effect between the shaft core 1 and the tool holder 2, the outlet position of the second shaft core cooling channel outlet 1121 is set to be close to the inner end of the second shaft core mating surface 112.

[0085] In any of the above embodiments, such as Figure 5 As shown, at least one shaft core cooling channel outlet includes a third shaft core cooling channel outlet 1131 that opens onto the outer peripheral wall of the shaft core 1;

[0086] like Figure 4 and Figure 8 As shown, the electric spindle also includes a front flange 3 sleeved on the outer peripheral wall of the spindle core 1 and a pressure cover 4 for fixing the front flange 3. An air sealing ring 5 is provided between the front flange 3 and the pressure cover 4 and the spindle core 1, and the air sealing ring 5 is clearance-fitted with the front flange 3 and the pressure cover 4.

[0087] like Figure 9 As shown, the air sealing ring 5 is provided with an air hole 51 and an air storage groove 52, and the outlet 1131 of the third shaft core cooling channel is connected to the air hole 51.

[0088] In this embodiment of the invention, a third shaft cooling channel outlet 1131, which communicates with the shaft cooling channel 14, is provided on the outer peripheral wall of the shaft core 1. When the spindle is in a clamped state, since the tool holder mating surface 21 of the tool holder 2 is in contact with the shaft core mating surface 11 of the shaft core 1, the gas can only flow out from the radial hole on the outer peripheral wall of the shaft core 1 (i.e., the third shaft cooling channel outlet 1131) to the gas storage groove 52 of the gas sealing ring 5. The gas sealing ring is provided with a gas storage groove and air holes 51 evenly distributed around the central axis. The gas is discharged through the gap between the air holes 51, the gas sealing ring 5 and the pressure cap 4 and the front flange 3, thereby achieving the gas sealing effect at the front end of the spindle (i.e., at the second end 13 of the shaft core 1).

[0089] In any of the above embodiments, such as Figure 2 and Figure 7 As shown, at least a portion of the shaft core cooling channel 14 is an axial groove 142 formed on the outer peripheral wall of the shaft core 1;

[0090] The electric spindle also includes a motor rotor 6, which is sleeved on the outer peripheral wall of the spindle core 1 and seals the axial groove 142.

[0091] In this embodiment of the invention, the axial length of the motor rotor is greater than the length of the axial groove 142, thereby ensuring that gas does not leak when passing through the axial groove 142 on the shaft core 1.

[0092] Specifically, such as Figure 2 , Figures 5-7 As shown, the shaft core cooling channel 14 includes a first shaft core cooling channel section 141, an axial groove 142, a second shaft core cooling channel section 143, and a third shaft core cooling channel section 144 connected in sequence.

[0093] The first core cooling channel 141 is inclined or perpendicular to the axis of the core 1, the axial groove 142 and the third core cooling channel 144 are parallel to the axis of the core, and the second core cooling channel 143 is perpendicular to the axis of the core 1.

[0094] It is worth noting that the reason why the first shaft core cooling channel section 141, the axial groove 142, the second shaft core cooling channel section 143, and the third shaft core cooling channel section 144 are arranged as described above in this embodiment of the invention is from the perspective of part processing. Specifically, the axial groove 142 and the third shaft core cooling channel section 144 are arranged parallel to the axis of the shaft core 1, and the second shaft core cooling channel section 142 is arranged perpendicular to the axis of the shaft core 1 because it is easier to process. The first shaft core cooling channel section 141 is set in an inclined state or perpendicular to the central axis of the shaft core 1, mainly because it is affected by the length of the motor rotor 6, the relative position of the intermediate spacer 74, and the length of the axial groove 142.

[0095] In any of the above embodiments, such as Figure 3 As shown, the electric spindle also includes:

[0096] The pull rod assembly 7 is located inside the shaft core 1 and connected to the tool holder 2. The pull rod assembly 7 has a first motion state that drives the tool holder mating surface 21 to fit with the shaft core mating surface 11 and a second motion state that drives the tool holder mating surface 21 to separate from the shaft core mating surface 11.

[0097] like Figure 7 As shown, the tie rod assembly 7 is also provided with a tie rod cooling channel 71, wherein the outlet of the tie rod cooling channel 71 is designed such that when the tie rod assembly 7 switches between the first motion state and the second motion state, the outlet of the tie rod cooling channel 71 is always connected to the inlet of the shaft core cooling channel 14.

[0098] In this embodiment of the invention, by setting the pull rod cooling channel 71 on the pull rod assembly 7 to always be connected to the spindle cooling channel 14 on the spindle core 1, the compressed gas in the pull rod cooling channel 71 can be discharged to the front end of the spindle core 1 through the spindle cooling channel 14, regardless of whether the electric spindle is in the clamped state or the unclamped state, thereby achieving a cooling effect and / or an airtight effect and / or a cleaning effect on the front end of the spindle core 1.

[0099] Specifically, such as Figure 7 As shown, the pull rod assembly includes:

[0100] Pull rod body 72;

[0101] A front spacer 73 and a middle spacer 74 are fitted onto the outside of the pull rod body 72, with the front spacer 73 positioned relative to the middle spacer 74 closer to the second end 13 of the shaft core 1, wherein the position of the front spacer 73 relative to the shaft core 1 is fixed.

[0102] The elastic element includes a first elastic element 75 and a second elastic element 76. The first elastic element 75 is disposed on the pull rod body 72 and located between the front partition 73 and the middle partition 74. The pull rod body 72 is provided with a limiting surface. The second elastic element 76 is disposed between the middle partition 74 and the limiting surface.

[0103] The tie rod cooling channel 71 includes a first tie rod cooling channel section 711 disposed on the tie rod body 72 and a second tie rod cooling channel section 712 disposed on the intermediate spacer 74 and connected to the first tie rod cooling channel section 711, wherein the outlet of the second tie rod cooling channel section 712 is connected to the inlet of the shaft core cooling channel 14.

[0104] The pull rod body 72 can move along the axial direction. During the movement of the pull rod, the elastic elements {first elastic element 75 and second elastic element 76} are compressed, and the intermediate spacer 74 moves in the axial direction. The fixed plate is fixed at the tail end of the shaft core 1 {that is, away from the second end 13 of the shaft core}, which plays a limiting role for the pull rod body 72. The axial movement of the pull rod body 72 can drive the tool holder 2 to move axially, thereby realizing the tool clamping and tool release operation of the electric spindle.

[0105] More specifically, such as Figure 7 and Figure 10 As shown, the second tie rod cooling channel section 712 includes a second tie rod cooling channel air inlet section 7121, a second tie rod cooling channel middle section 7122, and a second tie rod cooling channel air outlet section 7123 connected in sequence.

[0106] The second tie rod cooling channel inlet section 7121 is connected to the first tie rod cooling channel section 711, and the second tie rod cooling channel outlet section 7123 is connected to the shaft core cooling channel 14; wherein

[0107] The width of the air inlet of the second tie rod cooling channel inlet section 7121 in the direction of the shaft core 1 is greater than the width of the air outlet of the first tie rod cooling channel section 711 in the direction of the shaft core 1.

[0108] The width of the air outlet of the second tie rod cooling channel air outlet section 7123 in the direction of the axis of the shaft core 1 is greater than the width of the air inlet of the shaft core cooling channel 14 in the direction of the axis of the shaft core 1.

[0109] In this embodiment of the invention, by setting the width of the air inlet section 7121 of the second tie rod cooling channel and the air outlet section 1723 of the second tie rod cooling channel to be relatively large, it can be ensured that the tie rod cooling channel 71 on the tie rod assembly 7 is always connected with the shaft core cooling channel 14 on the shaft core 1 when the tie rod body 72 moves axially.

[0110] It is worth noting that, in order to further improve the connectivity between the cooling channel 71 of the tie rod and the cooling channel 14 of the shaft core, the stiffness of the intermediate spacer 74 in this embodiment of the invention is set to be greater than that of the elastic element. This ensures that when the tie rod body 72 moves axially, the intermediate spacer 74 will not undergo significant elastic deformation, thus not affecting the flow rate of compressed gas flowing in and out of the intermediate spacer 74, thereby ensuring the cooling effect and / or airtightness and / or cleaning effect of the electric spindle.

[0111] In any of the above embodiments, in order to improve the overall cooling effect and / or airtightness and / or cleaning effect of the electric spindle, the spindle core cooling channel 14 in the embodiments of the present invention is provided with multiple sets, and the multiple sets of spindle core cooling channels 14 are evenly distributed in the circumferential direction of the spindle core 1.

[0112] Multiple sets of cooling channels 71 are provided for the tie rod assembly 7, and these multiple sets of cooling channels 71 are evenly distributed in the circumferential direction of the tie rod assembly 7; among them

[0113] Each set of shaft core cooling channels 14 is connected to a set of tie rod cooling channels 71.

[0114] In this embodiment of the invention, by setting multiple sets of shaft core cooling channels 14 evenly distributed around the shaft core 1 and multiple sets of tie rod cooling channels 71 evenly distributed around the tie rod assembly 7, cooling and / or air sealing and / or cleaning can be achieved at multiple positions around the front end of the electric spindle shaft core 1, thereby improving the cooling effect and / or air sealing effect and / or cleaning effect of the electric spindle.

[0115] In any of the above embodiments, such as Figure 7 As shown, the pull rod body 72 is also provided with a main channel 77. The inlet of the main channel 77 is connected to a compressed air source, and the outlet is used to connect with the inlet of multiple sets of pull rod cooling channels 71 and to distribute the cooling medium {i.e., compressed gas} in the main channel 77 to multiple pull rod cooling channels 71.

[0116] Specifically, such as Figure 7 As shown, the outlet end of the main flow channel 77 is connected to the first pull rod cooling flow channel section 711 on the pull rod body 72. Multiple pull rod cooling flow channel sections 711 are evenly distributed in the circumferential direction of the pull rod body 72. The outlet end of the main flow channel 77 is opened in the middle of the pull rod body 72, so that the compressed gas in the pull rod body 72 can be evenly distributed to multiple first pull rod cooling flow channel sections 711. This avoids the cooling effect and / or air sealing effect and / or cleaning effect at a certain position at the front end of the shaft core 1 due to insufficient compressed gas in a certain group of first pull rod cooling flow channel sections 711.

[0117] In any of the above embodiments, such as Figure 4 As shown, the pull rod assembly also includes a pull claw structure 78, a pull rod connector 79, and a rotary joint 70;

[0118] The tie rod body 72 has a tie rod head end and a tie rod tail end that are arranged opposite to each other in its axial direction;

[0119] The first end of the pull rod is connected to the tool holder 2 via the pull claw structure 78, and the second end of the pull rod is connected to the rotary joint 80 via the pull rod connector 79.

[0120] In any of the above embodiments, such as Figure 4 As shown, the electric spindle also includes a stator assembly 8, a front bearing 9, and a rear bearing 10;

[0121] The stator assembly 8 is sleeved on the outside of the shaft core 1. One end of the stator assembly 8 is rotatably engaged with the second end 13 of the shaft core 1 through the front bearing 9, and the other end is rotatably engaged with the first end 12 of the shaft core 1 through the rear bearing 10.

[0122] The following is combined Figures 1-10 The electric spindle in the embodiments of the present invention will be described in detail as follows:

[0123] like Figures 1-10 As shown, the aforementioned gland 4, front flange 3, motor stator assembly 8, and rotary joint 80 are fixed to the main body of the spindle and are stationary parts; the shaft core 1, locking nut, air seal ring 5, pull claw structure 78, motor rotor 6, pull rod body 72, front spacer 73, first elastic element 75, second elastic element 76, middle spacer 74, fixed plate, and pull rod connector 79 are rotating parts. The locking nut is threadedly connected to the shaft core 1, and its relative position to the shaft core 1 is fixed. The gas sealing ring 5 is fixed on the locking nut. The pull claw structure 78 is located inside the shaft core 1. When the electric spindle performs the tool release action, the axial movement of the pull rod realizes the clamping and releasing of the tool holder 2 by the shaft core 1. In the clamped state, the tool 2 is fixed to the shaft core 1 by the pull claw structure 78. In the released state, the tool holder 2 is separated from the shaft core 1. The front spacer 73, the pull rod body 72, the first elastic element 75, the second elastic element 76, and the middle spacer 74 are sleeved inside the shaft core 1. The front spacer 73 is fixed in position relative to the shaft core 1. The pull rod body 72 can move along the axial direction. During the movement, the first elastic element 75 and the second elastic element 76 are compressed, and the middle spacer 74 moves in the axial direction. The fixed plate is fixed at the tail end of the shaft core 1 and plays a limiting role for the pull rod body 72. One end of the pull rod connecting rod 79 is fixedly connected to the tail end of the pull rod body 72, and the other end is connected to the rotary joint 80.

[0124] The flow process of compressed gas along each component of the electric spindle is as follows:

[0125] In the clamped state, gas enters from the gas inlet of the rotary joint 80, passes through the inner hole of the pull rod connecting rod 79, and reaches the pull rod body 72. It then passes through the axially opened main channel 77 on the pull rod body 72 and the air holes in the radially opened first pull rod cooling channel section 711 to reach the intermediate spacer 74. The circumferentially evenly distributed oblique holes on the shaft core 1 (i.e., the first shaft core cooling channel section 141) communicate with the air grooves in the intermediate spacer 74 (i.e., the second pull rod cooling channel section 712). Gas then passes through the axial grooves 142 on the shaft core 1 and the second shaft core cooling channel section 712. In section 143 and the third shaft core cooling flow channel section 144, compressed gas reaches the air storage groove 52 on the air sealing ring 5. When the compressed gas flows through the flow channel on the shaft core 1, it can cool the shaft core 1 and reduce the thermal deformation of the shaft core. There is a gap between the air sealing ring 5 and the front flange 3 and the gland 4. The compressed gas comes out from the air hole 51 of the air sealing ring 5 and is discharged to the outside of the electric spindle through the gap, thereby achieving the air sealing effect at the front end of the spindle and preventing impurities from entering the spindle from the front end during the machining process.

[0126] When the tool is released, a gap is created between the end face and the tapered surface of the tool holder 2 and the core 1 (i.e., the core mating surface 11 of the core 1 and the tool holder mating surface 21 of the tool holder 2 are in contact). After the compressed gas flows through the axial hole of the core 1 (i.e., through the third core cooling channel section 144), part of the compressed gas flows out from the oblique hole (i.e., the outlet 1121 of the second core cooling channel) and the axial hole (i.e., the outlet 1111 of the first core cooling channel) of the core 1, and the other part flows out from the radial hole (i.e., the outlet 1131 of the third core cooling channel) of the core 1, thereby achieving the cleaning effect on the end face and tapered surface of the tool holder 2 and the core 1.

[0127] On the other hand, this invention also provides a machine tool comprising an electric spindle with the above-described structure.

[0128] Example 2

[0129] The difference between this embodiment and embodiment 1 is that: in this embodiment, the shaft core mating surface 11 is inclined to the axis of the shaft core 1, and the shaft core mating surface 11 includes an inner end of the shaft core mating surface close to the axis of the shaft core 1 and an outer end of the shaft core mating surface away from the axis of the shaft core, and the outer end of the shaft core mating surface is located closer to the middle of the shaft core than the inner end of the shaft core mating surface.

[0130] At least one of the spindle cooling channel outlets includes a first spindle cooling channel outlet that opens into the spindle mating surface, and the outlet direction of the first spindle cooling channel outlet forms an angle α with the tool holder mating surface 21 in the range of 20° to 70°.

[0131] That is, the shaft core mating surface 11 in this embodiment has only one inclined surface, instead of the two surfaces mentioned in embodiment 1 {i.e., the first shaft core mating surface and the second shaft core mating surface}.

[0132] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0133] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. An electric spindle, characterized by, include: A shaft core (1) has a first end (12) and a second end (13) disposed opposite to each other in its axial direction. The second end (13) of the shaft core (1) is provided with a shaft core mating surface (11). The second end (13) of the shaft core (1) is used to connect to the tool holder (2). The shaft core mating surface (11) is used to mate with the tool holder mating surface (21) of the tool holder (2). The electric spindle has a clamping state when the spindle core mating surface (11) and the tool holder mating surface (21) are in contact, and a loosening state when the spindle core mating surface (11) and the tool holder mating surface (21) are separated; The shaft core (1) is provided with a shaft core cooling channel (14), the shaft core cooling channel (14) is provided with at least one shaft core cooling channel outlet, and the outlet end of at least one shaft core cooling channel outlet opens into the shaft core mating surface (11); The shaft core mating surface (11) includes a first shaft core mating surface (111) and a second shaft core mating surface (112), and the tool holder mating surface (21) includes a first tool holder mating surface (211) that mates with the first shaft core mating surface (111) and a second tool holder mating surface (212) that mates with the second shaft core mating surface (112). The at least one of the shaft cooling channel outlets includes a first shaft cooling channel outlet (1111) opening onto the first shaft mating surface (111) and a second shaft cooling channel outlet (1121) opening onto the second shaft mating surface (112); The at least one of the shaft cooling channel outlets includes a third shaft cooling channel outlet (1131) that opens on the outer peripheral wall of the shaft (1). The electric spindle also includes a front flange (3) sleeved on the outer peripheral wall of the spindle core (1) and a pressure cap (4) for fixing the front flange (3). An air sealing ring (5) is provided between the front flange (3) and the pressure cap (4) and the spindle core (1). The air sealing ring (5) is clearance-fitted with the front flange (3) and the pressure cap (4). The air sealing ring (5) is provided with an air hole (51) and an air storage groove (52), and the outlet (1131) of the third shaft core cooling channel is connected to the air hole (51).

2. The electric spindle according to claim 1, characterized in that, The first shaft core mating surface (111) is arranged perpendicular to the axis of the shaft core (1), and the first shaft core mating surface (111) includes an inner end of the first shaft core mating surface close to the axis and an outer end of the first shaft core mating surface away from the axis; The second shaft core mating surface (112) is inclined to the axis of the shaft core (1), and the second shaft core mating surface includes an inner end of the second shaft core mating surface close to the axis and an outer end of the second shaft core mating surface away from the axis; The outer end of the second shaft core mating surface is connected to the inner end of the first shaft core mating surface, and the outer end of the second shaft core mating surface is located near the middle of the shaft core (1) relative to the inner end of the second shaft core mating surface.

3. The electric spindle according to claim 2, characterized in that, The outlet direction of the first shaft core cooling channel outlet (1111) is perpendicular to the first tool holder mating surface (211), and the outlet direction of the second shaft core cooling channel outlet (1121) forms an angle α with a range of 20° to 70° between it and the second tool holder mating surface (212).

4. The electric spindle according to claim 3, characterized in that, The outlet position of the second shaft cooling channel outlet (1121) is close to the inner end of the second shaft mating surface (112).

5. The electric spindle according to claim 1, characterized in that, The shaft core mating surface (11) is inclined to the axis of the shaft core (1). The shaft core mating surface (11) includes an inner end of the shaft core mating surface close to the axis of the shaft core (1) and an outer end of the shaft core mating surface away from the axis of the shaft core. The outer end of the shaft core mating surface is located closer to the middle of the shaft core than the inner end of the shaft core mating surface. At least one of the shaft cooling channel outlets includes a first shaft cooling channel outlet that opens into the shaft mating surface, wherein the outlet direction of the first shaft cooling channel outlet forms an angle α with the tool holder mating surface (21) in the range of 20° to 70°.

6. The electric spindle according to any of claims 1-5, characterized in that, At least a portion of the shaft core cooling channel (14) is an axial groove (142) formed on the outer peripheral wall of the shaft core (1). The electric spindle also includes a motor rotor (6), which is sleeved on the outer peripheral wall of the shaft core (1) and seals the axial groove (142).

7. The electric spindle according to claim 6, characterized in that, The core cooling channel (14) includes a first core cooling channel section (141), the axial groove (142), a second core cooling channel section (143), and a third core cooling channel section (144) connected in sequence. The first core cooling channel section (141) is inclined or perpendicular to the axis of the core (1), the axial groove (142) and the third core cooling channel section (144) are parallel to the axis of the core, and the second core cooling channel section (143) is perpendicular to the axis of the core (1).

8. The electric spindle according to claim 1, characterized in that, The electric spindle also includes: A pull rod assembly (7) is disposed inside the shaft core (1) and connected to the tool holder (2). The pull rod assembly (7) has a first motion state that drives the tool holder mating surface (21) to fit with the shaft core mating surface (11) and a second motion state that drives the tool holder mating surface (21) to separate from the shaft core mating surface (11). The pull rod assembly (7) is also provided with a pull rod cooling channel (71), wherein the outlet of the pull rod cooling channel (71) is designed such that when the pull rod assembly (7) switches between the first motion state and the second motion state, the outlet of the pull rod cooling channel (71) is always connected to the inlet of the shaft core cooling channel (14).

9. The electric spindle according to claim 8, characterized in that, The tie rod assembly includes: Pull rod body (72); A front spacer (73) and a middle spacer (74) are sleeved on the outside of the pull rod body (72), and the front spacer (73) is positioned relative to the middle spacer (74) close to the second end (13) of the shaft core (1), wherein the position of the front spacer (73) relative to the shaft core (1) is fixed; The elastic element includes a first elastic element (75) and a second elastic element (76). The first elastic element (75) is disposed on the pull rod body (72) and located between the front partition (73) and the middle partition (74). The pull rod body (72) is provided with a limiting surface. The second elastic element (76) is disposed between the middle partition (74) and the limiting surface. The pull rod cooling channel (71) includes a first pull rod cooling channel section (711) disposed on the pull rod body (72) and a second pull rod cooling channel section (712) disposed on the intermediate spacer (74) and connected to the first pull rod cooling channel section (711), wherein the outlet of the second pull rod cooling channel section (712) is connected to the inlet of the shaft core cooling channel (14).

10. The electric spindle according to claim 9, characterized in that, The second tie rod cooling channel section (712) includes a second tie rod cooling channel inlet section (7121), a second tie rod cooling channel middle section (7122), and a second tie rod cooling channel outlet section (7123) connected in sequence. The second tie rod cooling channel inlet section (7121) is connected to the first tie rod cooling channel section (711), and the second tie rod cooling channel outlet section (7123) is connected to the shaft core cooling channel (14); wherein The width of the air inlet of the second tie rod cooling channel inlet section (7121) in the direction of the axis of the shaft core (1) is greater than the width of the air outlet of the first tie rod cooling channel section (711) in the direction of the axis of the shaft core (1); The width of the air outlet of the second tie rod cooling channel air outlet section (7123) in the direction of the axis of the shaft core (1) is greater than the width of the air inlet of the shaft core cooling channel (14) in the direction of the axis of the shaft core (1).

11. The electric spindle according to claim 9, characterized in that, The stiffness of the intermediate spacer (74) is greater than the stiffness of the elastic element.

12. The electric spindle according to any one of claims 8-11, characterized in that, The core cooling channel (14) is provided in multiple sets, and the multiple sets of core cooling channels (14) are evenly distributed in the circumferential direction of the core (1); The tie rod cooling channels (71) are provided in multiple sets, and the multiple sets of tie rod cooling channels (71) are evenly distributed in the circumferential direction of the tie rod assembly (7); wherein Each set of the shaft core cooling channels (14) is connected to a set of the tie rod cooling channels (71).

13. The electric spindle according to claim 9, characterized in that, The pull rod body (72) is also provided with a main channel (77), which is used to connect with multiple sets of pull rod cooling channels (71) and distribute the cooling medium in the main channel (77) to multiple pull rod cooling channels (71).

14. The electric spindle according to claim 9, characterized in that, The pull rod assembly also includes a pull claw structure (78), a pull rod connector (79), and a rotary joint (80). The tie rod body (72) has a tie rod head end and a tie rod tail end that are arranged opposite to each other in its axial direction; The first end of the pull rod is connected to the handle (2) via the pull claw structure (78), and the last end of the pull rod is connected to the rotary joint (80) via the pull rod connector (79).

15. The electric spindle according to claim 1, characterized in that, The electric spindle also includes a stator assembly (8), a front bearing (9), and a rear bearing (10). The stator assembly (8) is sleeved on the outside of the shaft core (1), with one end of it rotatingly engaged with the second end (13) of the shaft core (1) through the front bearing (9), and the other end rotatingly engaged with the first end (12) of the shaft core (1) through the rear bearing (10).

16. A machine tool, characterized in that, The electric spindle includes any one of claims 1-15.

Images