Machine tool

Abstract

The application discloses a machine tool, which comprises a rotary table, a hydrostatic spindle, a rotary connecting device, a grinding cooling system and a spindle hydraulic system, the hydrostatic spindle is fixed on the rotary table, and the hydrostatic spindle is provided with a liquid inlet cavity and an oil return cavity; the rotary connecting device comprises a first pipe body and a second pipe body, the first pipe body is fixed on the rotary table, at least two first flow channels which are isolated from each other are arranged in the first pipe body, at least one first flow channel is communicated with the liquid inlet cavity, and at least one first flow channel is communicated with the oil return cavity. The second pipe body is connected to the first pipe body and can rotate relative to the first pipe body around an axis of the second pipe body, at least two second flow channels which are isolated from each other are arranged in the second pipe body, and the at least two second flow channels are communicated with the at least two first flow channels in a one-to-one correspondence; the grinding cooling system is connected with at least one second flow channel; and the spindle hydraulic system is connected with at least one second flow channel. The application solves the problem that the transmission pipelines of lubricating oil and cooling liquid are prone to winding.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machining devices, in particular to a machine tool. BACKGROUND

[0002] Hydrostatic spindle is a spindle structure working by hydrostatic principle, which relies on external hydraulic oil supply system to inject lubricating oil into hydrostatic bearing and generate pressure oil film. Therefore, the front and rear ends of hydrostatic spindle support the shaft core in a non-contact manner. Hydrostatic spindle has the advantages of adjustable oil film stiffness, small friction resistance and high stability, and is widely used in the field of ultra-precision machine tool machining.

[0003] At present, the oil return and cooling liquid transmission pipelines of most hydrostatic spindles are directly connected outside the hydrostatic spindles. In this way, the structures of the oil return and cooling liquid transmission pipelines are relatively discrete. When the flow of lubricating oil and cooling liquid is large or the hydrostatic spindle is installed on a rotary table to rotate around the B shaft, the transmission pipelines of lubricating oil and cooling liquid are easy to entangle, which causes poor oil return and liquid inlet, even blockage, and further affects the oil film support stiffness of the spindle and the cooling liquid outlet flow. SUMMARY

[0004] The main purpose of the present application is to provide a machine tool to solve the problem that when the flow of lubricating oil and cooling liquid is large or the hydrostatic spindle is installed on a rotary table to rotate around the rotary table, the transmission pipelines of lubricating oil and cooling liquid are easy to entangle.

[0005] According to one aspect of the present application, a machine tool is provided, comprising:

[0006] a rotary table;

[0007] a hydrostatic spindle fixed on the rotary table, the hydrostatic spindle being provided with a liquid inlet cavity and an oil return cavity;

[0008] a rotary connection device, the rotary connection device comprising a first pipe body and a second pipe body, the first pipe body being fixed on the rotary table, the first pipe body being provided with at least two first flow channels isolated from each other, at least one of the first flow channels being in communication with the liquid inlet cavity and at least one of the first flow channels being in communication with the oil return cavity; the second pipe body being connected to the first pipe body and being rotatable around its own axis relative to the first pipe body, the second pipe body being provided with at least two second flow channels isolated from each other, the at least two second flow channels being in one-to-one correspondence with the at least two first flow channels;

[0009] a grinding cooling system connected with at least one of the second flow channels, the grinding cooling system being used to provide cooling liquid to the liquid inlet cavity;

[0010] a main shaft hydraulic system connected with the second flow channel, the main shaft hydraulic system being used to recycle lubricating oil from the oil return cavity.

[0011] Further, one of the first pipe body and the second pipe body is provided with a plug-in groove, and the other of the first pipe body and the second pipe body is provided with a plug-in part matched with the plug-in groove.

[0012] Further, the plug-in groove is arranged at one end of the second pipe body close to the first pipe body, the plug-in part is a part of the first pipe body plugged into the plug-in groove, and at least two communication cavities are formed between the plug-in part and the plug-in groove and are isolated from each other, at least two first flow channels correspond to the at least two communication cavities one by one in communication, and at least two second flow channels correspond to the at least two communication cavities one by one in communication.

[0013] Further, the second flow channel comprises a first transmission channel, and the communication cavity comprises:

[0014] a first cavity formed between one end of the plug-in part close to the plug-in groove and the plug-in groove, wherein the length of the first transmission channel extends away from the first cavity and is in communication with the first cavity, and the first transmission channel is in communication with at least one first flow channel through the first cavity.

[0015] Further, the first flow channel comprises:

[0016] an oil return channel arranged in the first pipe body along the axial direction of the first pipe body and in communication with the first cavity through the plug-in part and the first cavity, wherein the part of the first pipe body located outside the plug-in groove is provided with an oil return inlet in communication with the oil return channel.

[0017] Further, the second flow channel further comprises a second transmission channel, the second transmission channel extends to the plug-in groove and the plug-in part between one end close to the first pipe body and is in communication with the plug-in groove, and the communication cavity further comprises:

[0018] a second cavity, which is an annular groove arranged on the outer wall surface of the plug-in part, and the second transmission channel is in communication with at least one first flow channel through the second cavity.

[0019] Further, the first flow channel further comprises:

[0020] The liquid inlet channel is arranged in the first pipe body along the axial direction and communicates with the first cavity through the plug-in part and the second cavity, wherein one end of the liquid inlet channel close to the first cavity is isolated from the first cavity by a plug, and the liquid inlet channel communicates with the second transmission channel through the second cavity.

[0021] Further, the inner wall of the liquid inlet channel is provided with a first liquid inlet and a second liquid inlet, the first liquid inlet is arranged at the groove bottom of the annular groove, and the second liquid inlet is arranged at the part of the first pipe body outside the plug-in groove, and the second liquid inlet is used for communicating with the liquid inlet cavity.

[0022] Further, the inner wall of the plug-in groove is provided with a relief groove, the groove bottom of the relief groove is provided with a communication hole communicating with the second transmission channel, and the relief groove is arranged opposite to the annular groove and recessed away from the annular groove; and / or, the relief groove is arranged on the inner wall of the plug-in groove along the circumferential direction of the annular groove.

[0023] Further, the rotating connection device further comprises:

[0024] A first sealing assembly is arranged on the plug-in part and located between the first cavity and the second cavity, and is used for sealing the plug-in gap between the plug-in part and the plug-in groove and sealing the first cavity and the second cavity.

[0025] And / or, a second sealing assembly is arranged on the plug-in part and located on the side of the second cavity away from the first sealing assembly, and is used for sealing the plug-in gap between the plug-in part and the plug-in groove.

[0026] In this application, a rotary connection device is provided on the machine tool's rotary table. This device connects the hydrostatic spindle to the grinding cooling system and the spindle hydraulic system. A first tube of the rotary connection device is fixed to the rotary table, and a second tube is connected to the first tube and can rotate relative to the first tube around its own axis. The second tube can be fixed to an external structure and connected to both the grinding cooling system and the spindle hydraulic system via a second flow channel within it. When the rotary table rotates, the hydrostatic spindle and the first tube remain relatively stationary, while the second tube rotates relative to the first tube. The return oil generated by the hydrostatic spindle enters the first tube from the return oil chamber and is then transmitted back to the spindle hydraulic system through one of the second flow channels of the second tube. The grinding cooling system inputs coolant into the first tube along the other second flow channel of the second tube, and the coolant is then transported to the inlet chamber of the hydrostatic spindle via the first flow channel within the first tube. During this process, the rotary connection device forms a dynamic rotary sealing structure to achieve bidirectional transmission of lubricating oil and coolant. The transmission pipelines of lubricating oil and coolant will not entangle with each other, ensuring the smooth flow of lubricating oil and coolant and preventing blockage. This ensures the oil film support rigidity of the hydrostatic spindle and the inlet flow rate of the coolant, effectively improving the return oil efficiency and the inlet efficiency of the hydrostatic spindle. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0028] Figure 1 A schematic diagram of the assembly structure of a machine tool rotary table, a hydrostatic spindle, and a rotary connection device provided in an embodiment of the present invention;

[0029] Figure 2 for Figure 1 Schematic diagram of the rotating connection device;

[0030] Figure 3 This is a schematic diagram of the structure of the first tube.

[0031] Figure 4 for Figure 2 The right view;

[0032] Figure 5 for Figure 4 AA section view;

[0033] Figure 6 for Figure 5 A cross-sectional view of the second tube in the middle.

[0034] The above figures include the following reference numerals:

[0035] 10, rotary table; 20, hydrostatic spindle; 30, rotary connecting device; 31, first pipe body; 311, plug-in part; 312, oil return channel; 121, oil return inlet; 313, liquid inlet channel; 314, blocking piece; 315, first liquid inlet; 316, second liquid inlet; 32, second pipe body; 321, plug-in groove; 322, first transmission channel; 323, second transmission channel; 324, avoiding groove; 325, oil return outlet; 326, cooling liquid inlet; 33, first chamber; 34, second chamber; 341, annular groove; 35, sealing ring; 36, joint base; 40, connecting pipeline; 50, tool changing spindle; 60, grinding head box. DETAILED DESCRIPTION

[0036] It should be noted that the embodiments and features in the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0037] It should be noted that the terms used herein are only intended to describe specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that, when the terms "comprise" and / or "include" are used in the specification, there is a presence of a feature, step, operation, device, component and / or a combination thereof.

[0038] Unless specifically stated otherwise, the relative arrangements of the components and steps illustrated in these embodiments and the numerical expressions and values set forth in these embodiments do not limit the scope of the present application. It should be understood that the various parts of the drawings are not necessarily drawn to scale. Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the present application. In all examples shown and discussed in this specification, any specific value should be interpreted as merely an example, and not as a limitation. Therefore, other examples of the exemplary embodiments can have different values. It should be noted that similar reference numerals and letters in the following drawings represent similar items, and therefore, once an item is defined in one drawing, it need not be discussed further in subsequent drawings.

[0039] When the flow of lubricating oil and cooling liquid is large or the hydrostatic spindle 20 is installed on the rotary table 10 and rotates around the rotary table 10, in view of the fact that the connecting pipelines for transmitting lubricating oil and cooling liquid are prone to entangle with each other, the first embodiment of the present application provides a machine tool, such as Figure 1As shown, the machine tool comprises a rotary table 10, a hydrostatic spindle 20, a rotary connecting device 30, a grinding cooling system and a spindle hydraulic system. The hydrostatic spindle 20 is fixed on the rotary table 10, and the hydrostatic spindle 20 is provided with a liquid inlet cavity and an oil return cavity. Figure 2 As shown, the rotary connecting device 30 comprises a first pipe body 31 and a second pipe body 32. The first pipe body 31 is fixed on the rotary table 10, and the first pipe body 31 is provided with at least two first flow channels which are isolated from each other. At least one first flow channel is in communication with the liquid inlet cavity, and at least one first flow channel is in communication with the oil return cavity. Specifically, the first flow channels of the first pipe body 31 are communicated to the hydrostatic spindle 20 through a communication pipeline 40. The second pipe body 32 is connected to the first pipe body 31 and can rotate relative to the first pipe body 31 about its own axis. The second pipe body 32 is provided with at least two second flow channels which are isolated from each other. The at least two second flow channels are in one-to-one correspondence with the at least two first flow channels. The grinding cooling system is connected to at least one second flow channel. The grinding cooling system is used to provide cooling liquid to the liquid inlet cavity, so that the tool on the hydrostatic spindle 20 can cool the workpiece through the cooling liquid. The spindle hydraulic system is connected to at least one second flow channel. The spindle hydraulic system is used to recover lubricating oil from the oil return cavity. When the hydrostatic spindle 20 works, the spindle hydraulic system injects lubricating oil into the hydrostatic bearing of the hydrostatic spindle 20 and generates a pressure oil film. The hydrostatic spindle 20 generates oil return. Whether the rotary table 10 rotates or not, the oil return generated by the hydrostatic spindle 20 flows into the rotary connecting device 30 through the oil return cavity, and is sent back to the spindle hydraulic system by the rotary connecting device 30.

[0040] As can be seen, a rotary connection device 30 is provided on the rotary table 10 of the machine tool provided in this embodiment of the invention. The rotary connection device 30 is used to connect the hydrostatic spindle 20 with the grinding cooling system and the spindle hydraulic system. The first tube 31 of the rotary connection device 30 is fixed on the rotary table 10, and the second tube 32 is connected to the first tube 31 and can rotate relative to the first tube 31 around its own axis. The second tube 32 can be fixed to an external structure and connected to the grinding cooling system and the spindle hydraulic system through a second flow channel inside it. The external structure can be a wiring box, and the wiring box is provided with transmission pipes that communicate with the second flow channels inside the second tube 32. Through these transmission pipes, at least one second flow channel is connected to the grinding cooling system and at least one second flow channel is connected to the spindle hydraulic system. Since the second tube 32 rotates relative to the first tube 31, the transmission pipes will not become entangled. When the rotary table 10 rotates, the hydrostatic spindle 20 remains stationary relative to the first tube 31, while the second tube 32 rotates relative to the first tube 31. The return oil generated by the hydrostatic spindle 20 enters the first tube 31 from the return oil chamber and is then transmitted back to the spindle hydraulic system through one of the second flow channels of the second tube 32. The grinding cooling system inputs coolant into the first tube 31 along another second flow channel of the second tube 32, and then delivers it to the inlet chamber of the hydrostatic spindle 20 through the first flow channel within the first tube 31. During this process, the rotary connecting device 30 forms a dynamic rotary sealing structure, enabling bidirectional transmission of lubricating oil and coolant. The transmission lines of lubricating oil and coolant do not entangle with each other, ensuring smooth flow of lubricating oil and coolant without blockage. This guarantees the oil film support stiffness of the hydrostatic spindle 20 and the inlet flow rate of the coolant, effectively improving the return oil efficiency of the spindle and the inlet efficiency of the coolant.

[0041] When the turntable 10 rotates, the turntable 10 presses... Figure 1 The direction indicated by the middle arrow X drives the hydrostatic spindle 20 and the first tube 31 of the rotary connecting device 30 to rotate. Since the first tube 31 is relatively stationary with respect to the hydrostatic spindle 20, the second tube 32 can rotate relative to the first tube 31. Therefore, the transmission pipelines between the second tube 32 and the grinding cooling system and the spindle hydraulic system, as well as the connecting pipeline 40 between the first tube 31 and the hydrostatic spindle 20, will not become entangled.

[0042] like Figures 3 to 6As shown, the first pipe body 31 and the second pipe body 32 are provided with a plug-in groove 321 on one of them, and a plug-in part 311 on the other of them, which is matched with the plug-in groove 321. The first pipe body 31 and the second pipe body 32 are integrally connected by the plug-in groove 321 and the plug-in part 311, to realize the bidirectional transmission of the lubricating oil and the cooling liquid for the hydrostatic spindle 20, which can not only avoid the winding of the transmission pipeline of the lubricating oil and the transmission pipeline of the cooling liquid, but also effectively improve the oil return efficiency of the spindle and the liquid inlet efficiency of the cooling liquid.

[0043] Specifically, the plug-in groove 321 is arranged at one end of the second pipe body 32 close to the first pipe body 31, the plug-in part 311 is the part of the first pipe body 31 inserted into the plug-in groove 321, and at least two communication chambers are formed between the plug-in part 311 and the plug-in groove 321, which are isolated from each other. At least two first flow channels and at least two second flow channels correspond to the at least two communication chambers one by one. The oil return generated by the hydrostatic spindle 20 enters at least one communication chamber from at least one first flow channel of the first pipe body 31, and then enters at least one second flow channel in the second pipe body 32 through the communication chamber, and is transmitted to the spindle hydraulic system by the at least one second flow channel. When it is needed to grind and cool the workpiece by the cutter on the hydrostatic spindle 20, the grinding and cooling system sends the cooling liquid along at least one second flow channel in the second pipe body 32 to another at least one communication chamber, and the cooling liquid enters another at least one first flow channel in the first pipe body 31 from the communication chamber, so as to be transmitted to the hydrostatic spindle 20 along the first flow channel, and the cutter on the hydrostatic spindle 20 can grind and cool the workpiece by the cooling liquid. When the flow of the lubricating oil and the cooling liquid is large, or the hydrostatic spindle 20 rotates with the rotary table 10, since the lubricating oil and / or the cooling liquid are transmitted through different flow channels and communication chambers in the rotary connection device 30 respectively, the transmission pipelines for the lubricating oil and the cooling liquid will not be wound, and the oil return efficiency of the hydrostatic spindle 20 and the liquid inlet efficiency of the cooling liquid can be effectively improved.

[0044] As Figure 5As shown, the second flow channel includes a first transmission channel 322, and the communication chamber includes a first chamber 33, which is a chamber formed between the one end of the insertion part 311 close to the insertion groove 321 and the insertion groove 321. The length of the first transmission channel 322 extends in a direction away from the first chamber 33 and communicates with the first chamber 33, and the first transmission channel 322 communicates with at least one first flow channel through the first chamber 33. Specifically, a communication pipeline 40 is arranged between the liquid static pressure spindle 20 and the first pipe body 31, one end of the communication pipeline 40 communicates with the oil return chamber in the liquid static pressure spindle 20, and the other end communicates with at least one first flow channel of the first pipe body 31. When the liquid static pressure spindle 20 works, the spindle hydraulic system injects lubricating oil into the static pressure bearing of the liquid static pressure spindle 20 and generates a pressure oil film, at the same time, the liquid static pressure spindle 20 generates oil return, no matter whether the rotary table 10 rotates or not, the oil return generated by the liquid static pressure spindle 20 flows into at least one first flow channel in the first pipe body 31 through the oil return chamber along the communication pipeline 40, the oil return enters the first chamber 33 through the first flow channel, and then flows back to the spindle hydraulic system through the first transmission channel 322 from the first chamber 33.

[0045] In the embodiment of the application, the first flow channel in the first pipe body 31 includes an oil return channel 312, which is arranged in the first pipe body 31 along the axial direction of the first pipe body 31 and communicates with the first chamber 33 through the insertion part 311. The part of the first pipe body 31 outside the insertion groove 321 is provided with an oil return inlet 121 communicating with the oil return channel 312, the oil return inlet 121 communicates with the communication pipeline 40, and the oil return generated by the liquid static pressure spindle 20 is transmitted to the oil return channel 312 in sequence along the communication pipeline 40 and the oil return inlet 121, so as to enter the first chamber 33 through the oil return channel 312 and flow back to the spindle hydraulic system along the first transmission channel 322. No matter whether the rotary table 10 rotates or not, since the liquid static pressure spindle 20 and the first pipe body 31 are always relatively static, when the communication pipeline 40 transmits the oil return in the liquid static pressure spindle 20 to the oil return channel 312 of the first pipe body 31, the communication pipeline 40 will not be wound to affect the transmission of the oil return. Since the second pipe body 32 can rotate relative to the first pipe body 31, when the oil return is transmitted back to the spindle hydraulic system through the first chamber 33 and the first transmission channel 322 in the second pipe body 32, the transmission pipeline between the second pipe body 32 and the spindle hydraulic system will not be wound with each other, which ensures the smoothness of the lubricating oil conduction, the pipelines through which the lubricating oil flows will not be blocked, and the oil film support stiffness of the liquid static pressure spindle 20 is guaranteed, and the oil return efficiency of the liquid static pressure spindle 20 is improved.

[0046] The second flow channel in the second pipe body 32 further comprises a second transmission channel 323 extending to the joint groove 321 and communicating with the joint groove 321 at one end of the second pipe body 32 close to the first pipe body 31, and the second transmission channel 323 is arranged in a radial direction of the second pipe body 32 and spaced from the first transmission channel 322, thereby ensuring the isolation between the first transmission channel 322 and the second transmission channel 323. The communication chamber formed between the joint groove 321 and the joint portion 311 of the first pipe body 31 further comprises a second chamber 34, which is an annular groove 341 arranged on the outer wall surface of the joint portion 311, and the second transmission channel 323 communicates with at least one first flow channel through the second chamber 34. The second transmission channel 323 communicates with the grinding cooling system, the grinding cooling system inputs the cooling liquid into the second transmission channel 323 of the second pipe body 32, the cooling liquid flows into at least one first flow channel in the first pipe body 31 along the annular groove 341 (i.e. the second chamber 34) along the second transmission channel 323, and then the cooling liquid is delivered to the hydrostatic spindle 20 through the first flow channel and the communication pipeline 40 communicating with the first flow channel, and the tool on the hydrostatic spindle 20 can perform grinding cooling on the workpiece through the delivered cooling liquid.

[0047] Specifically, as shown in Figure 5 The first flow channel in the first pipe body 31 further comprises a liquid inlet channel 313 arranged in the first pipe body 31 in an axial direction of the first pipe body 31 and communicating with the first chamber 33 through the joint portion 311. The liquid inlet channel 313 is spaced from the first chamber 33 at one end thereof through a plug 314, and the liquid inlet channel 313 communicates with the second transmission channel 323 through the second chamber 34. The plug 314 is a pipe plug, also known as a screw plug, a throat plug, a blind plug, a blind cap, etc. In this embodiment, the pipe plug is used to isolate the liquid inlet channel 313 from the first chamber 33, thereby ensuring that the liquid inlet channel 313 only communicates with the annular groove 341 (i.e. the second chamber 34) on the first pipe body 31, and reducing the machining difficulty of the first pipe body 31. The cooling liquid flows into the liquid inlet channel 313 along the annular groove 341 along the second transmission channel 323, and then the cooling liquid is delivered to the hydrostatic spindle 20 through the liquid inlet channel 313 and the communication pipeline 40 communicating with the liquid inlet channel 313, thereby ensuring the smoothness of the conduction of the cooling liquid, preventing the transmission pipeline, the communication pipeline 40, etc. from being wound and blocked, ensuring the liquid flow of the cooling liquid into the hydrostatic spindle 20, and improving the liquid efficiency of the cooling liquid.

[0048] The inner wall of the liquid inlet channel 313 in the first pipe body 31 is provided with a first liquid inlet 315 and a second liquid inlet 316. As Figure 3As shown, the first liquid inlet 315 is arranged at the groove bottom of the annular groove 341 to make the liquid inlet channel 313 communicate with the annular groove 341 for the transmission of the cooling liquid. The second liquid inlet 316 is arranged at the part of the first pipe body 31 outside the plug-in groove 321, and the second liquid inlet 316 is used to communicate with the liquid inlet cavity. Specifically, the second liquid inlet 316 communicates with the liquid inlet cavity of the hydrostatic spindle 20 through the communication pipeline 40. The grinding cooling system flows the cooling liquid along the second transmission channel 323 of the second pipe body 32 along the annular groove 341 into the liquid inlet channel 313, and then enters the second liquid inlet 316 in the liquid inlet channel 313 to enter the communication pipeline 40, and the cooling liquid is delivered to the hydrostatic spindle 20 through the communication pipeline 40. In the process of transmitting the cooling liquid through the second pipe body 32 and the first pipe body 31, whether the rotary table 10 drives the hydrostatic spindle 20 and the rotary connection device 30 to rotate or not, since the hydrostatic spindle 20 is always relatively stationary with the first pipe body 31 of the rotary connection device 30, and the second pipe body 32 can rotate relative to the first pipe body 31, there will be no winding between the cooling liquid transmission pipeline arranged between the second pipe body 32 and the grinding cooling system, or between the communication pipeline 40 arranged between the first pipe body 31 and the hydrostatic spindle 20, ensuring the smoothness of the cooling liquid.

[0049] As shown in the figure, Figure 6 As shown, the inner wall of the plug-in groove 321 is further provided with an avoidance groove 324, the groove bottom of the avoidance groove 324 is provided with a communication hole communicating with the second transmission channel 323, and the avoidance groove 324 is arranged opposite to the annular groove 341 and recessed away from the annular groove 341, thereby increasing the cross-sectional area of the second cavity 34, and the second cavity 34 formed between the avoidance groove 324 and the annular groove 341 can accommodate more cooling liquid, thereby increasing the liquid inlet flow of the cooling liquid. In a preferred embodiment of the present application, the avoidance groove 324 is arranged on the inner wall of the plug-in groove 321 along the circumference of the annular groove 341, that is, the second cavity 34 formed between the avoidance groove 324 and the annular groove 341 forms a larger annular liquid inlet cavity, and more cooling liquid can flow in the second cavity 34, thereby further increasing the liquid inlet flow of the cooling liquid. It can be seen that, in the embodiment of the present application, the cooling liquid flows into the first pipe body 31 through the second cavity 34, and then is delivered to the hydrostatic spindle 20 by the first pipe body 31, which not only ensures the smoothness of the cooling liquid, but also increases the liquid inlet flow of the cooling liquid, thereby improving the grinding cooling efficiency of the hydrostatic spindle 20 on the workpiece.

[0050] To prevent the whole rotating connection device 30 from leaking liquid or oil or the different communicating chambers from leaking to each other during the rotation of the second pipe body 32 relative to the first pipe body 31, the rotating connection device 30 provided by the embodiment of the application further comprises a first sealing assembly and a second sealing assembly. The first sealing assembly is arranged on the insertion part 311 and located between the first chamber 33 and the second chamber 34. The first sealing assembly is used to seal the insertion gap between the insertion part 311 and the insertion groove 321 and seal the first chamber 33 and the second chamber 34 from each other, so that the first chamber 33 and the second chamber 34 will not leak to each other, and the oil return and the cooling liquid can be isolated during the transmission process. The second sealing assembly is arranged on the insertion part 311 and located on the side of the second chamber 34 away from the first sealing assembly. The second sealing assembly is used to seal the insertion gap between the insertion part 311 and the insertion groove 321, so as to avoid the leakage of the cold zone liquid in the second chamber 34 to the outside of the first pipe body 31 along the insertion gap.

[0051] Specifically, the first sealing assembly comprises at least two sealing rings 35, and the at least two sealing rings 35 are respectively embedded in at least two sealing grooves arranged on the first pipe body 31 and tightly fit with the groove walls of the insertion groove 321 of the second pipe body 32. The second sealing assembly can also comprise at least two sealing rings 35, and the at least two sealing rings 35 are respectively embedded in at least two sealing grooves arranged on the first pipe body 31 and tightly fit with the groove walls of the insertion groove 321 of the second pipe body 32. Thus, the rotation sealing property during the rotation of the second pipe body 32 relative to the first pipe body 31 is ensured, and the generation of liquid leakage and oil leakage is prevented.

[0052] The second embodiment of the application is based on the above-mentioned embodiment and in combination with the drawings Figures 1 to 6 An application embodiment of a machine tool is provided. In the application embodiment, the hydrostatic spindle 20 is connected with a grinding cooling system and a spindle hydraulic system through the rotating connection device 30. The grinding cooling system is used to provide cooling liquid to the hydrostatic spindle 20, and the spindle hydraulic system is used to collect the lubricating oil generated from the hydrostatic spindle 20. That is to say, the application embodiment designs a rotating connection device 30 with a rotating dynamic sealing structure to collect the oil return and liquid inlet device of the hydrostatic spindle 20, so as to realize the centralization and modularization of the spindle oil return and liquid inlet system and ensure the smoothness of the liquid inlet and oil return pipeline.

[0053] As Figure 1As shown, the machine tool in the application embodiment includes a rotary table 10, a tool changing spindle 50, a communication pipeline 40, a rotary connection device 30, a grinding head box 60, a hydrostatic spindle 20, and a grinding wheel arranged at the end of the hydrostatic spindle 20. The hydrostatic spindle 20 is installed in the grinding head box 60, and the grinding head box 60 and the tool changing spindle 50 are both bolted and installed on the rotary table 10. The rotary connection device 30 is provided with a joint base 36 arranged at the end of the first pipe body 31 away from the second pipe body 32, and the joint base 36 of the rotary connection device 30 is also bolted and installed on the rotary table 10. When the rotary table 10 rotates, the tool changing spindle 50 and the hydrostatic spindle 20 are relatively stationary with the joint base 36 and the first pipe body 31 on the joint base 36, and the second pipe body 32 fixedly connected with the external structure rotates relative to the first pipe body 31. The machine tool bed base is provided with a grinding wheel tool magazine, and the tool changing spindle 50 is turned to the tool magazine, so that different grinding wheels can be selected for tool replacement according to different working conditions.

[0054] The oil return generated by the tool changing spindle 50 and the hydrostatic spindle 20 is communicated with the rotary connection device 30 through the communication pipeline 40. The first pipe body 31 and the second pipe body 32 of the rotary connection device 30 cooperate to form a first chamber 33 and a second chamber 34 for transmitting the oil return and the cooling liquid, respectively. The first chamber 33 and the second chamber 34 are sealed and isolated by a sealing ring 35 to prevent liquid leakage between the first chamber 33 and the second chamber 34. The second pipe body 32 is fixed to the external structure, and when the rotary table 10 rotates, the second pipe body 32 rotates relative to the first pipe body 31, so that the rotary connection device 30 as a whole forms a dynamic sealing structure, realizing bidirectional transmission of the oil return and the cooling liquid, and improving the oil return efficiency of the oil return and the liquid inlet efficiency of the cooling liquid.

[0055] Please refer to Figure 5 The working process of the hydrostatic spindle 20 of the machine tool for transmitting the oil return and the cooling liquid through the rotary connection device 30 is as follows:

[0056] When the hydrostatic spindle 20 works, the spindle hydraulic system injects lubricating oil into the hydrostatic bearing of the hydrostatic spindle 20 and generates a pressure oil film. At the same time, the tool changing spindle 50 or the hydrostatic spindle 20 generates oil return. Regardless of whether the rotary table 10 rotates, the oil return generated by the tool changing spindle 50 or the hydrostatic spindle 20 flows into the oil return inlet 121 on the first pipe body 31 through the communication pipeline 40, then enters the oil return channel 312 from the oil return inlet 121, and then sequentially passes through the first chamber 33, the first transmission channel 322, and reaches the oil return outlet 325, and then flows back to the spindle hydraulic system, efficiently and without blockage, completing the transmission of the oil return, and ensuring the oil film support stiffness of the hydrostatic spindle 20.

[0057] The second pipe body 32 is provided with a cooling liquid inlet 326 communicated with the second transmission channel 323 of the second pipe body 32. The grinding cooling system delivers the cooling liquid to the cooling liquid inlet 326 of the second pipe body 32, and the cooling liquid enters the second cavity 34 through the second transmission channel 323, then enters the communication pipeline 40 through the second liquid inlet 316 on the first pipe body 31 along the liquid inlet channel 313 from the second cavity 34, and finally enters the hydrostatic spindle 20 through the communication pipeline 40, so that the grinding wheel provided on the hydrostatic spindle 20 can use the flowing cooling zone liquid to grind and cool the workpiece.

[0058] It can be seen that, by means of the rotating connection device 30, the application embodiment realizes the centralization and modularization of the oil return and liquid inlet pipeline of the hydrostatic spindle 20, avoids the winding of the liquid inlet and oil return pipeline when the rotary table 10 rotates, or the pipeline blockage caused by the large flow of the oil return and cooling liquid, and effectively improves the oil return efficiency of the hydrostatic spindle 20 and the liquid inlet efficiency of the cooling liquid.

[0059] For the convenience of description, spatial relative terms such as "above", "upper", "top surface", "upper" and the like can be used herein to describe the spatial positional relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "above" other devices or structures will be positioned "below" or "below" other devices or structures. Thus, the example term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated by 90 degrees or in other orientations), and the spatial relative description used herein is interpreted accordingly.

[0060] In addition, it should be noted that the use of "first", "second" and the like to define parts is only for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the present application.

[0061] The above is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A machine tool, characterized in that, include: Turntable (10); A hydrostatic spindle (20) is fixed on the turntable (10). The hydrostatic spindle (20) is provided with an inlet chamber and an oil return chamber. A rotary connecting device (30) includes a first tube (31) and a second tube (32). The first tube (31) is fixed on the turntable (10). The first tube (31) has at least two mutually isolated first flow channels. At least one of the first flow channels is connected to the liquid inlet chamber and at least one of the first flow channels is connected to the oil return chamber. The second tube (32) is connected to the first tube (31) and can rotate relative to the first tube (31) around its own axis. The second tube (32) has at least two mutually isolated second flow channels. The at least two second flow channels are connected to the at least two first flow channels in a one-to-one correspondence. A grinding cooling system, the grinding cooling system being connected to at least one of the second flow channels, the grinding cooling system being used to supply coolant to the inlet chamber; A spindle hydraulic system, the spindle hydraulic system being connected to at least one of the second flow channels, the spindle hydraulic system being used to recover lubricating oil from the return oil chamber.

2. The machine tool according to claim 1, characterized in that, One of the first tube (31) and the second tube (32) is provided with a insertion groove (321), and the other of the first tube (31) and the second tube (32) is provided with an insertion part (311) that is adapted to the insertion groove (321).

3. The machine tool according to claim 2, characterized in that, The insertion groove (321) is disposed at one end of the second tube (32) near the first tube (31). The insertion part (311) is the part of the first tube (31) inserted into the insertion groove (321). At least two interconnected chambers are formed between the insertion part (311) and the insertion groove (321) and are mutually isolated. At least two first flow channels are connected to at least two interconnected chambers in a one-to-one correspondence. At least two second flow channels are connected to at least two interconnected chambers in a one-to-one correspondence.

4. The machine tool according to claim 3, characterized in that, The second flow channel includes a first transmission channel (322), and the communicating chamber includes: The first chamber (33) is a chamber formed between the end of the plug portion (311) near the plug groove (321) and the plug groove (321). The length of the first transmission channel (322) extends away from the first chamber (33) and communicates with the first chamber (33). The first transmission channel (322) communicates with at least one first flow channel through the first chamber (33).

5. The machine tool according to claim 4, characterized in that, The first flow channel includes: The oil return channel (312) is arranged along the axial direction of the first pipe body (31) inside the first pipe body (31) and passes through the insertion part (311) to communicate with the first chamber (33). The portion of the first pipe body (31) outside the insertion groove (321) is provided with an oil return inlet (121) that communicates with the oil return channel (312).

6. The machine tool according to claim 4, characterized in that, The second flow channel further includes a second transmission channel (323), one end of which extends near the first tube body (31) between the insertion groove (321) and the insertion portion (311) and communicates with the insertion groove (321). The communicating chamber further includes: The second chamber (34) is an annular groove (341) provided on the outer wall surface of the plug part (311). The second transmission channel (323) is connected to at least one of the first flow channels through the second chamber (34).

7. The machine tool according to claim 6, characterized in that, The first flow channel also includes: The liquid inlet channel (313) is arranged axially along the first tube body (31) inside the first tube body (31) and passes through the plug part (311) to communicate with the first chamber (33). The end of the liquid inlet channel (313) near the first chamber (33) is isolated from the first chamber (33) by a plug (314), and the liquid inlet channel (313) is connected to the second transmission channel (323) through the second chamber (34).

8. The machine tool according to claim 7, characterized in that, The inner wall of the liquid inlet channel (313) is provided with a first liquid inlet (315) and a second liquid inlet (316). The first liquid inlet (315) is located at the bottom of the annular groove (341), and the second liquid inlet (316) is located in the part of the first tube body (31) outside the insertion groove (321). The second liquid inlet (316) is used to communicate with the liquid inlet chamber.

9. The machine tool according to claim 6, characterized in that, An avoidance groove (324) is provided on the inner wall of the insertion groove (321). The bottom of the avoidance groove (324) is provided with a communication hole that communicates with the second transmission channel (323). The avoidance groove (324) is disposed opposite to the annular groove (341) and is recessed in a direction away from the annular groove (341). And / or, the avoidance groove (324) is disposed around the inner wall of the insertion groove (321) along the circumference of the annular groove (341).

10. The machine tool according to any one of claims 6 to 9, characterized in that, The rotary connecting device (30) further includes: A first sealing assembly is disposed on the insertion part (311) and located between the first chamber (33) and the second chamber (34). The first sealing assembly is used to seal the insertion gap between the insertion part (311) and the insertion groove (321) and to seal and isolate the first chamber (33) and the second chamber (34). And / or, a second sealing assembly disposed on the insertion portion (311) and located on the side of the second chamber (34) away from the first sealing assembly, the second sealing assembly being used to seal the insertion gap between the insertion portion (311) and the insertion groove (321).

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