A cooling structure, an electric spindle, and a machine tool

Abstract

This invention provides a cooling structure, an electric spindle, and a machine tool, belonging to the field of electric spindle technology. The cooling structure includes: a bushing having a first end face, a second end face, and an inner circumferential surface; a rear bearing housing and a front bearing housing, which are assembled on the first and second end face sides of the bushing. The rear bearing housing has an outer circumferential surface that mates with the inner circumferential surface of the bushing after assembly, and the front bearing housing has an outer circumferential surface that mates with the inner circumferential surface of the bushing after assembly. A cooling channel for the rear bearing housing is formed by the mating of the inner circumferential surface of the bushing and the outer circumferential surface of the rear bearing housing, and a cooling channel for the front bearing housing is formed by the mating of the inner circumferential surface of the bushing and the outer circumferential surface of the front bearing housing. The bushing also has a first coolant channel and a second coolant channel extending axially inside it. The first coolant channel connects the rear bearing housing cooling channel and the front bearing housing cooling channel, and the second coolant channel connects the front bearing housing cooling channel.

Description

Technical Field

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

[0002] Currently, electric spindles are a type of spindle that integrates the spindle motor and the machine tool spindle in the field of intelligent equipment CNC machine tools. In addition to the spindle itself, electric spindles also integrate lubrication, cooling, encoders, tool changing, etc. Compared with traditional mechanical spindles, electric spindles have advantages such as compact structure, low vibration and noise, stable machining performance, and high machining accuracy.

[0003] Because electric spindles integrate the motor into the spindle unit and operate at high speeds, they generate a significant amount of heat during operation. If this heat is not controlled, critical components such as bearings, spacers, and the motor inside the spindle may expand, deform, or even seize and burn out. This deteriorates the spindle's thermal and dynamic characteristics, affecting its normal operation. Therefore, measures must be taken to control the spindle temperature and keep it constant within a certain range. Summary of the Invention

[0004] To overcome the problem that excessive heat generated during operation of electric spindles in related technologies can easily lead to expansion, deformation, or even jamming and burnout of key components such as bearings, spacers, and motors inside the electric spindle, this invention proposes a cooling structure, electric spindle, and machine tool that can effectively dissipate heat from the electric spindle during operation.

[0005] The first aspect of this invention provides a cooling structure for cooling the spindle core of an electric spindle, the cooling structure comprising:

[0006] A bushing having a first end face and a second end face in its axial direction and an inner circumferential surface between the first end face and the second end face.

[0007] The rear bearing housing and the front bearing housing are used to assemble on the first end face side and the second end face side of the bushing. The rear bearing housing has an outer circumferential surface that mates with the inner circumferential surface of the bushing after assembly. The front bearing housing has an outer circumferential surface that mates with the inner circumferential surface of the bushing after assembly. A cooling channel for the rear bearing housing is formed by the mating of the inner circumferential surface of the bushing and the outer circumferential surface of the front bearing housing. A cooling channel for the front bearing housing is formed by the mating of the inner circumferential surface of the bushing and the outer circumferential surface of the front bearing housing.

[0008] The bushing is also provided with a first coolant channel and a second coolant channel extending in its axial direction. The inlet end of the first coolant channel and the outlet end of the second coolant channel are located on the same side. The first coolant channel connects the rear bearing housing cooling channel and the front bearing housing cooling channel, and the second coolant channel connects the front bearing housing cooling channel.

[0009] In the above technical solution, a rear bearing housing cooling groove is provided on the outer circumferential surface of the rear bearing housing, and the rear bearing housing cooling groove and the inner circumferential surface of the bushing form a rear bearing housing cooling flow channel.

[0010] A cooling groove for the front bearing housing is provided on the outer circumferential surface of the front bearing housing, and the cooling groove for the front bearing housing and the inner circumferential surface of the bushing form a cooling channel for the front bearing housing.

[0011] The bushing is also provided with a first liquid inlet groove, a first liquid outlet groove, a second liquid inlet groove, and a second liquid outlet groove;

[0012] The inlet end of the first liquid inlet tank is connected to the first coolant flow channel, and the outlet end is connected to the rear bearing housing cooling flow channel. The inlet end of the first liquid outlet tank is connected to the rear bearing housing cooling flow channel, and the outlet end is connected to the first coolant flow channel.

[0013] The inlet end of the second liquid inlet tank is connected to the first coolant flow channel, and the outlet end is connected to the front bearing housing cooling flow channel. The inlet end of the second liquid outlet tank is connected to the front bearing housing cooling flow channel, and the outlet end is connected to the second coolant flow channel.

[0014] In the above technical solution, the rear bearing housing cooling groove includes a first rear bearing housing cooling groove, a second rear bearing housing cooling groove, and a third rear bearing housing cooling groove arranged adjacent to each other along the axial direction of the outer peripheral surface of the rear bearing housing. The second rear bearing housing cooling groove is used to connect the first rear bearing housing cooling groove and the third rear bearing housing cooling groove, and the groove depth of the second rear bearing housing cooling groove is less than the groove depth of the first rear bearing housing cooling groove and the groove depth of the third rear bearing housing cooling groove. The first rear bearing housing cooling groove is arranged near the inlet end of the first coolant flow channel relative to the third rear bearing housing cooling groove. The first inlet groove connects the first rear bearing housing cooling groove and the first coolant flow channel, and the first outlet groove connects the third rear bearing housing cooling groove and the first coolant flow channel.

[0015] The front bearing housing cooling groove includes a first front bearing housing cooling groove, a second front bearing housing cooling groove, and a third front bearing housing cooling groove arranged adjacent to each other along the axial direction of the outer peripheral surface of the front bearing housing. The second front bearing housing cooling groove is used to connect the first front bearing housing cooling groove and the third front bearing housing cooling groove, and the groove depth of the second front bearing housing cooling groove is less than the groove depth of the first front bearing housing cooling groove and the groove depth of the third front bearing housing cooling groove. The first front bearing housing cooling groove is located away from the outlet end of the second coolant flow channel relative to the third front bearing housing cooling groove. The second inlet groove connects the first front bearing housing cooling groove and the first coolant flow channel, and the second outlet groove connects the third front bearing housing cooling groove and the second coolant flow channel.

[0016] In the above technical solution, the first liquid inlet groove and the second liquid outlet groove are arc-shaped grooves opened along the circumferential direction of the bushing, and the first liquid outlet groove and the second liquid inlet groove are annular grooves opened along the circumferential direction of the bushing.

[0017] The first and third rear bearing housing cooling grooves are annular grooves opened along the circumferential direction of the rear bearing housing, and the second rear bearing housing cooling groove is an arc-shaped groove opened along the circumferential direction of the rear bearing housing.

[0018] The first and third front bearing housing cooling grooves are annular grooves opened along the circumferential direction of the front bearing housing, while the second front bearing housing cooling groove is an arc-shaped groove opened along the circumferential direction of the front bearing housing.

[0019] In the above technical solution, the bushing is also provided with multiple cooling circulation channels extending along its axial direction, and the multiple cooling circulation channels are evenly distributed in the circumferential direction of the bushing.

[0020] The cooling circulation channel has a first end near the rear bearing housing and a second end near the front bearing housing in the axial direction of the bushing. The cooling circulation channel is connected to the first liquid outlet tank near the first end and to the second liquid inlet tank near the second end.

[0021] In the above technical solution, the minimum distance between the location of the first coolant flow channel and the cooling circulation flow channel and the shaft sleeve axis is D1;

[0022] The minimum distance between the location of the second coolant flow channel and the axis of the bushing is D2;

[0023] Where D2 > D1;

[0024] The length of the first coolant flow channel and the cooling circulation flow channel in the axial direction of the bushing is L1;

[0025] The length of the second coolant flow channel in the axial direction of the bushing is L2;

[0026] Where L2 > L1.

[0027] In the above technical solution, the cooling structure also includes:

[0028] Piping tray, which is connected to the rear bearing housing, is equipped with an inlet pipe connector and an outlet pipe connector;

[0029] The rear bearing housing has an inlet connecting groove and an outlet connecting groove along its axial direction. The inlet pipe connector is connected to the inlet end of the first coolant flow channel through the inlet connecting groove, and the outlet pipe connector is connected to the outlet end of the second coolant flow channel through the outlet connecting groove.

[0030] In the above technical solution, the first coolant flow channel, the second coolant flow channel, and the cooling circulation flow channel all have openings on the first end face side of the bushing;

[0031] The opening of the first coolant flow channel serves as the inlet, and the opening of the coolant outlet channel serves as the outlet.

[0032] A sealing block is provided at the opening of the cooling circulation channel.

[0033] In the above technical solution, the inner circumferential surface of the bushing is constructed with a bushing mounting slot through which the motor shaft core passes, the inner circumferential surface of the rear bearing housing is constructed with a rear bearing housing mounting slot through which the motor shaft core passes, and the inner circumferential surface of the front bearing housing is constructed with a front bearing housing mounting slot through which the motor shaft core passes.

[0034] The bushing mounting slot is connected to the rear bearing housing mounting slot and the front bearing housing mounting slot at its two ends in the axial direction, respectively.

[0035] A second aspect of the present invention provides an electric spindle, comprising a motor shaft, a rear bearing, a front bearing, and the aforementioned cooling structure;

[0036] The motor shaft passes through the middle of the cooling structure. The rear bearing is installed in the mounting slot of the rear bearing housing and rotates with the motor shaft. The front bearing is installed in the mounting slot of the front bearing housing and rotates with the motor shaft.

[0037] In the above technical solution, the rear bearing is opposite to the rear bearing housing cooling channel in its radial direction;

[0038] The front bearing is opposite the front bearing housing cooling channel structure in its radial direction.

[0039] A third aspect of the present invention provides a machine tool including the electric spindle described above.

[0040] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0041] The cooling structure in this embodiment of the invention eliminates the traditional method of setting a waist-shaped groove on the end face of the bushing for cooling. Instead, it creates a first coolant flow channel and a second coolant flow channel along the axial direction inside the bushing. The inner circumferential surface of the bushing mates with the outer circumferential surfaces of the rear bearing housing and the front bearing housing to form the rear bearing housing cooling flow channel and the front bearing housing cooling flow channel, respectively. Combined with the first and second coolant flow channels formed inside the bushing, a complete electric spindle cooling circuit can be formed. Compared with the prior art, the elimination of the waist-shaped groove on the bushing frees up space on the end face of the bushing for the arrangement of advanced functions such as oil-air lubrication, ring spray, and sensors. This ensures the cooling effect on the electric spindle core and bearing parts without affecting the arrangement of advanced functions such as oil-air lubrication, ring spray, and sensors. Attached Figure Description

[0042] 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.

[0043] Figure 1 This is a cross-sectional view of the first flow channel of the coolant in Embodiment 1 of the cooling structure of the present invention;

[0044] Figure 2 This is a cross-sectional view of the second flow channel of the coolant in Embodiment 1 of the cooling structure of the present invention;

[0045] Figure 3 This is a three-dimensional structural schematic diagram of the rear bearing housing in Embodiment 1 of the cooling structure of the present invention;

[0046] Figure 4 This is a three-dimensional structural schematic diagram of the front bearing housing in Embodiment 1 of the cooling structure of the present invention;

[0047] Figure 5 This is a three-dimensional structural diagram of the bushing after concealment in Embodiment 1 of the cooling structure of the present invention;

[0048] Figure 6 This is a cross-sectional view of the first flow channel of the coolant in Embodiment 2 of the cooling structure of the present invention;

[0049] Figure 7 This is a cross-sectional view of the second flow channel of the coolant in Embodiment 2 of the cooling structure of the present invention.

[0050] Wherein: 1-shaft sleeve; 11-first coolant flow channel; 12-second coolant flow channel; 13-first inlet tank; 14-first outlet tank; 15-second inlet tank; 16-second outlet tank; 17-cooling circulation channel; 18-shaft sleeve mounting slot; 2-rear bearing housing; 21-rear bearing housing cooling tank; 211-first rear bearing housing cooling tank; 212-second rear bearing housing cooling tank; 213-third rear bearing housing cooling tank; 214-inlet... 215-Liquid outlet channel; 22-Rear bearing housing mounting slot; 3-Front bearing housing; 31-Front bearing housing cooling channel; 311-First front bearing housing cooling channel; 312-Second front bearing housing cooling channel; 313-Third front bearing housing cooling channel; 32-Front bearing housing mounting slot; 4-Rear bearing housing cooling channel; 5-Front bearing housing cooling channel; 6-Pipeline tray; 61-Inlet pipe connector; 62-Outlet pipe connector; 7-Sealing block. Detailed Implementation

[0051] 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.

[0052] Currently, existing electric spindles generate excessive heat during operation, which can easily cause expansion, deformation, or even seizure and burnout of critical components such as bearings, spacers, and motors. The cooling structure in this invention eliminates the traditional method of setting a waist-shaped groove on the end face of the bushing for cooling. Instead, it creates a first coolant flow channel and a second coolant flow channel along the axial direction inside the bushing. The inner circumferential surface of the bushing mates with the outer circumferential surfaces of the rear and front bearing seats to form the rear and front bearing seat cooling flow channels, respectively. Combined with the first and second coolant flow channels within the bushing, a complete electric spindle cooling circuit is formed. Compared to existing technologies, eliminating the waist-shaped groove on the bushing frees up space on the end face of the bushing for advanced functions such as oil-air lubrication, ring spraying, and sensors. This ensures effective cooling of the electric spindle core and bearings without compromising the implementation of these advanced functions.

[0053] The following is in conjunction with the appendix Figure 1-7 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.

[0054] Example 1

[0055] like Figures 1-5As shown, this embodiment proposes a cooling structure for cooling the spindle core of an electric spindle. The cooling structure includes:

[0056] Bushing 1 has a first end face and a second end face in its axial direction and an inner circumferential surface between the first end face and the second end face.

[0057] The rear bearing housing 2 and the front bearing housing 3 are used to assemble on the first end face side and the second end face side of the bushing 1. The rear bearing housing 2 has an outer circumferential surface that mates with the inner circumferential surface of the bushing after assembly. The front bearing housing 3 has an outer circumferential surface that mates with the inner circumferential surface of the bushing after assembly. The inner circumferential surface of the bushing and the outer circumferential surface of the rear bearing housing cooperate to form a rear bearing housing cooling channel 4. The inner circumferential surface of the bushing and the outer circumferential surface of the front bearing housing cooperate to form a front bearing housing cooling channel 5.

[0058] The bushing 1 is also provided with a first coolant channel 11 and a second coolant channel 12 extending in its axial direction. The inlet end of the first coolant channel 11 and the outlet end of the second coolant channel 12 are located on the same side. The first coolant channel 11 is connected to the rear bearing housing cooling channel 4 and the front bearing housing cooling channel 5, and the second coolant channel 12 is connected to the front bearing housing cooling channel 5.

[0059] In this embodiment of the invention, the flow direction of the coolant in the first coolant channel 11 is opposite to the flow direction of the coolant in the second coolant channel 12, and the coolant in the first coolant channel 11 can flow into the second coolant channel 12, and the coolant in the second coolant channel 12 can also flow into the first coolant channel 11. That is, the first coolant channel 11 and the second coolant channel 12 constitute part of a circulating cooling circuit.

[0060] Preferred, such as Figure 1 As shown, the coolant in the first coolant flow channel 11 flows from right to left, as... Figure 2 As shown, the coolant in the second coolant channel 12 flows from left to right.

[0061] The cooling structure in this embodiment of the invention eliminates the traditional method of setting a waist-shaped groove on the end face of the bushing 1 for cooling. Instead, it creates a first coolant flow channel 11 and a second coolant flow channel 12 along the axial direction inside the bushing 1. The inner circumferential surface of the bushing 1 mates with the outer circumferential surface of the rear bearing housing and the outer circumferential surface of the front bearing housing to form a rear bearing housing cooling flow channel 4 and a front bearing housing cooling flow channel 5, respectively. Combined with the first coolant flow channel 11 and the second coolant flow channel 12 formed inside the bushing 1, a complete electric spindle cooling circuit can be formed. Compared with the prior art, the elimination of the waist-shaped groove on the bushing 1 frees up space on the end face of the bushing for the arrangement of advanced functions such as oil-air lubrication, ring spray, and sensors. While ensuring the cooling effect on the electric spindle core and bearing parts, the arrangement of advanced functions such as oil-air lubrication, ring spray, and sensors is not affected.

[0062] Specifically, such as Figure 1 As shown, when the cooling medium enters the first coolant channel 11, a portion of the cooling medium enters the rear bearing housing cooling channel 4 to cool the rear bearing housing 2, while the other portion of the cooling medium flows along the axial direction of the bushing 1 through the first coolant channel 11 into the front bearing housing cooling channel 5 to cool the front bearing housing 3.

[0063] like Figure 2 As shown, since the front bearing housing cooling channel 5 is connected to the second coolant channel 12, the cooling medium flowing into the second coolant channel 12 can be discharged through the second coolant channel. Since the inlet end of the first coolant channel 11 and the outlet end of the second coolant channel 12 are located on the same side, the cooling medium can flow back and forth in the axial direction of the bushing 1, thereby forming a complete electric spindle cooling circuit to fully cool the electric spindle in the cooling structure.

[0064] In any of the above embodiments, such as Figure 3 and Figure 4 As shown, a rear bearing housing cooling groove 21 is provided on the outer circumferential surface of the rear bearing housing, and the rear bearing housing cooling groove 21 and the inner circumferential surface of the bushing form a rear bearing housing cooling channel 4.

[0065] A front bearing housing cooling groove 31 is provided on the outer circumferential surface of the front bearing housing, and the front bearing housing cooling groove 31 and the inner circumferential surface of the bushing form a front bearing housing cooling channel 5.

[0066] like Figure 1 , Figure 2 and Figure 5 As shown, the bushing 1 is also provided with a first liquid inlet groove 13, a first liquid outlet groove 14, a second liquid inlet groove 15 and a second liquid outlet groove 16;

[0067] The inlet end of the first liquid inlet tank 13 is connected to the first coolant flow channel 11, and the outlet end is connected to the rear bearing housing cooling flow channel 4. The inlet end of the first liquid outlet tank 14 is connected to the rear bearing housing cooling flow channel 4, and the outlet end is connected to the first coolant flow channel 11.

[0068] The inlet end of the second liquid inlet tank 15 is connected to the first coolant flow channel 11, and the outlet end is connected to the front bearing housing cooling flow channel 5. The inlet end of the second liquid outlet tank 16 is connected to the front bearing housing cooling flow channel 5, and the outlet end is connected to the second coolant flow channel 12.

[0069] In this embodiment of the invention, by setting a first liquid inlet tank 13 and a first liquid outlet tank 14 that are connected to the rear bearing housing cooling channel 4, the cooling medium flowing into the rear bearing housing cooling channel 4 through the first liquid inlet tank 14 can flow out through the first liquid outlet tank 15, thereby enabling the cooling medium in the rear bearing housing cooling channel 4 to flow continuously, thereby improving the cooling effect on the rear bearing housing 2.

[0070] In this embodiment of the invention, by setting a second liquid inlet trough 15 and a second liquid outlet trough 16 connected to the front bearing housing cooling channel 5, the cooling medium flowing into the front bearing housing cooling channel 5 through the second liquid inlet trough 15 can flow out through the second liquid outlet trough 16, thereby allowing the cooling medium in the front bearing housing cooling channel 5 to flow continuously, thereby improving the cooling effect on the front bearing housing 3.

[0071] Specifically, such as Figure 3 and Figure 4 As shown, the rear bearing housing cooling groove 21 includes a first rear bearing housing cooling groove 211, a second rear bearing housing cooling groove 212, and a third rear bearing housing cooling groove 213 adjacent to each other along the axial direction of the outer peripheral surface of the rear bearing housing. The second rear bearing housing cooling groove 212 is used to connect the first rear bearing housing cooling groove 211 and the third rear bearing housing cooling groove 213, and the groove depth of the second rear bearing housing cooling groove 212 is less than the groove depth of the first rear bearing housing cooling groove 211 and the groove depth of the third rear bearing housing cooling groove 213. The first rear bearing housing cooling groove 211 is located near the inlet end of the first coolant flow channel 11 relative to the third rear bearing housing cooling groove 213. The first inlet groove 13 connects the first rear bearing housing cooling groove 211 and the first coolant flow channel 11, and the first outlet groove 14 connects the third rear bearing housing cooling groove 213 and the first coolant flow channel 11.

[0072] The front bearing housing cooling groove 31 includes a first front bearing housing cooling groove 311, a second front bearing housing cooling groove 312, and a third front bearing housing cooling groove 313 arranged adjacent to each other along the axial direction of the outer peripheral surface of the front bearing housing. The second front bearing housing cooling groove 312 is used to connect the first front bearing housing cooling groove 311 and the third front bearing housing cooling groove 313, and the groove depth of the second front bearing housing cooling groove 312 is less than the groove depth of the first front bearing housing cooling groove 311 and the groove depth of the third front bearing housing cooling groove 313. The first front bearing housing cooling groove 311 is arranged away from the outlet end of the second coolant flow channel 12 relative to the third front bearing housing cooling groove 313. The second inlet groove 15 connects the first front bearing housing cooling groove 311 and the first coolant flow channel 11, and the second outlet groove 16 connects the third front bearing housing cooling groove 313 and the second coolant flow channel 12.

[0073] In this embodiment of the invention, the rear bearing housing cooling groove 21 is arranged as a first rear bearing housing cooling groove 211, a second rear bearing housing cooling groove 212, and a third rear bearing housing cooling groove 213 arranged adjacent to each other. The purpose is to increase the dwell time of the coolant in the rear bearing housing cooling channel and improve the cooling effect on the parts at the rear bearing housing 2.

[0074] In this embodiment of the invention, the front bearing housing cooling groove 31 is arranged adjacent to the first front bearing housing cooling groove 311, the second front bearing housing cooling groove 312, and the third front bearing housing cooling groove 313. The purpose is to increase the residence time of the coolant in the front bearing housing cooling channel 5 and improve the cooling effect on the parts at the front bearing housing 3.

[0075] In any of the above embodiments, such as Figure 1 , Figure 2 and Figure 5 As shown, the first liquid inlet groove 13 and the second liquid outlet groove 16 on the bushing 1 are arc-shaped grooves opened along the circumferential direction of the bushing 1, wherein the first liquid outlet groove 14 and the second liquid inlet groove 15 are annular grooves opened along the circumferential direction of the bushing 1.

[0076] like Figure 3 As shown, the first rear bearing housing cooling groove 211 and the third rear bearing housing cooling groove 213 on the rear bearing housing 2 are annular grooves opened along the circumferential direction of the rear bearing housing 2, and the second rear bearing housing cooling groove 212 is an arc-shaped groove opened along the circumferential direction of the rear bearing housing 2.

[0077] like Figure 4 As shown, the first front bearing housing cooling groove 311 and the third front bearing housing cooling groove 313 are annular grooves opened along the circumferential direction of the front bearing housing 3, and the second front bearing housing cooling groove 312 is an arc-shaped groove opened along the circumferential direction of the front bearing housing 3.

[0078] In this embodiment of the invention, by setting the second rear bearing housing cooling groove 212 and the second front bearing housing cooling groove 312 as arc-shaped grooves, on the one hand, the connection effect between the two adjacent groove segments can be guaranteed, and on the other hand, the residence time of the coolant in the rear bearing housing cooling channel 4 and the front bearing housing cooling channel 5 can be further improved, thereby further improving the cooling effect on the components at the rear bearing housing 2 and the front bearing housing 3.

[0079] In this embodiment of the invention, by designing the first liquid outlet groove 14 and the second liquid inlet groove 15 as annular grooves, the processing of annular grooves is simpler than that of waist-shaped grooves, and there is no need to use a large number of sealing rings for sealing as with waist-shaped grooves, which can reduce the processing cost of electric spindles.

[0080] In any of the above embodiments, such as Figure 1 , Figure 2 and Figure 5 As shown, the bushing 1 is also provided with a plurality of cooling circulation channels 17 extending along its axial direction, and the plurality of cooling circulation channels 17 are evenly distributed in the circumferential direction of the bushing 1.

[0081] The cooling circulation channel 17 has a first end near the rear bearing seat 2 and a second end near the front bearing seat 3 in the axial direction of the bushing 1. The cooling circulation channel 17 is connected to the first liquid outlet 14 near the first end and to the second liquid inlet 15 near the second end.

[0082] In this embodiment of the invention, by setting multiple cooling circulation channels 17, on the one hand, the first coolant channel 11 and the second coolant channel 12 can be connected together to form a complete cooling circulation loop in the cooling structure. On the other hand, the cooling effect of the bushing 1 on the electric spindle shaft can also be improved.

[0083] Furthermore, such as Figure 5 As shown, the minimum distance between the location of the first coolant flow channel 11 and the cooling circulation flow channel 17 and the axis of the bushing 1 is D1;

[0084] The minimum distance between the location of the second coolant flow channel 12 and the axis of the bushing 1 is D2;

[0085] Where D2 > D1, to ensure that the first liquid outlet 14 and the second liquid inlet 15 are not connected to the second coolant flow channel 12;

[0086] The length of the first coolant flow channel 11 and the cooling circulation flow channel 17 in the axial direction of the bushing 1 is L1;

[0087] The length of the second coolant flow channel 12 in the axial direction of the bushing 1 is L2;

[0088] Where L2 > L1, to ensure that the second coolant flow channel 12 can be connected to the second outlet tank 16.

[0089] It is worth noting that, in order to ensure the integrity of the cooling cycle, the first coolant flow channel 11 and the cooling circulation flow channel 17 only need to be connected to the second inlet tank 15, and there is no need to lengthen them further. However, the second coolant flow channel 12 needs to be connected to the second outlet tank 16. Therefore, L2 needs to be set to be greater than L1. On the other hand, in order to avoid processing errors in the actual processing process that cause the first coolant flow channel 11 or the cooling circulation flow channel 17 to be connected to the second outlet tank 16, L2 is set to be greater than L1.

[0090] In any of the above embodiments, the cooling structure further includes:

[0091] Pipeline plate 6 is connected to rear bearing seat 2. Pipeline plate 6 is provided with inlet pipe joint 61 and outlet pipe joint 62.

[0092] The rear bearing housing 2 is provided with an inlet connecting groove 214 and an outlet connecting groove 215 along its axial direction. The inlet pipe connector 61 is connected to the inlet end of the first coolant flow channel 11 through the inlet connecting groove 214, and the outlet pipe connector 62 is connected to the outlet end of the second coolant flow channel 12 through the outlet connecting groove 215.

[0093] The cooling medium enters the first coolant flow channel 11 through the inlet pipe joint 61 installed on the pipe plate 6, and completes the cooling cycle through the second coolant flow channel 12 and the outlet pipe joint 62 installed on the pipe plate 6.

[0094] In any of the above embodiments, such as Figure 1 and Figure 2 As shown, the first coolant flow channel 11, the second coolant flow channel 12, and the cooling circulation flow channel 17 all have openings on the first end face side of the bushing 1.

[0095] The opening of the first coolant flow channel 11 serves as the inlet, and the opening of the coolant outlet channel 12 serves as the outlet.

[0096] A sealing block 7 is provided at the opening of the cooling circulation channel 17.

[0097] By setting the sealing block 7, the cooling medium in the cooling circulation channel 17 is prevented from leaking from the opening.

[0098] In any of the above embodiments, such as Figure 1 and Figure 2 As shown, the inner circumferential surface of the bushing has a bushing mounting slot 18 through which the motor shaft core passes, the inner circumferential surface of the rear bearing housing has a rear bearing housing mounting slot 22 through which the motor shaft core passes, and the inner circumferential surface of the front bearing housing has a front bearing housing mounting slot 32 through which the motor shaft core passes.

[0099] The bushing mounting slot 18 is connected to the rear bearing housing mounting slot 22 and the front bearing housing mounting slot 32 at its two ends in the axial direction, respectively.

[0100] To better understand the cooling structure in the embodiments of the present invention, the following is in conjunction with... Figures 1-5 The cooling structure in the embodiments of the present invention will be described in detail below:

[0101] like Figures 1-5 As shown, the cooling structure mainly consists of the following components: front bearing housing 3, bushing 1, rear bearing housing 2, and pipe tray 6. Bushing 1 has a first coolant flow channel 11 and a second coolant flow channel 12. Bushing 1 and front bearing housing 3 form the front bearing housing cooling channel 5, and bushing 1 and rear bearing housing 2 form the rear bearing housing cooling channel 4. The first coolant flow channel 11, the rear bearing housing cooling channel 4, the front bearing housing cooling channel 5, and the second coolant flow channel 12 are connected in series to form a complete cooling structure for the electric spindle. The pipe tray 6 is equipped with an inlet pipe connector 61 and an outlet pipe connector 62. The coolant enters the cooling structure through the inlet pipe connector 61 and then completes the cooling cycle through the outlet pipe connector 62, thereby achieving efficient cooling of the electric spindle.

[0102] like Figure 1 As shown, the inlet pipe between the bushing 1 and the rear bearing housing 2 is sealed by a sealing ring, and the inlet pipe between the rear bearing housing 2 and the pipe plate 6 is also sealed by a sealing ring. The coolant enters the first coolant flow channel 11 through the inlet pipe joint 61 installed on the pipe plate 6.

[0103] like Figure 2 As shown, the outlet pipe between the bushing 1 and the rear bearing housing 2 is sealed by a sealing ring, and the outlet pipe between the rear bearing housing 2 and the pipe plate 6 is also sealed by a sealing ring. The coolant completes the cooling cycle through the second coolant flow channel 12 and the outlet pipe joint 62 installed on the pipe plate 4.

[0104] like Figure 1 , Figure 2 and Figure 5 As shown, the bushing 1 has a first coolant flow channel 11, a second coolant flow channel 12, several cooling circulation channels 17, a first inlet tank 13, a first outlet tank 14, a second inlet tank 15, and a second outlet tank 16. The first inlet tank 13 is connected to the first coolant flow channel 11, the first outlet tank 14 is connected to the first coolant flow channel 11 and the cooling circulation channels 17, the second inlet tank 15 is connected to the first coolant flow channel 11 and the cooling circulation channels 17, and the second outlet tank 16 is connected to the second coolant flow channel 12.

[0105] like Figure 4As shown, the front bearing housing 3 has a first front bearing housing cooling groove 311, a second front bearing housing cooling groove 312 and a third front bearing housing cooling groove 303, and the first front bearing housing cooling groove 311 and the third front bearing housing cooling groove 313 are connected through the second front bearing housing cooling groove 312.

[0106] like Figure 3 As shown, the rear bearing housing 2 has a first rear bearing housing cooling groove 211, a second rear bearing housing cooling groove 212 and a third rear bearing housing cooling groove 213, and the first rear bearing housing cooling groove 211 and the third rear bearing housing cooling groove 213 are connected through the second rear bearing housing cooling groove 212.

[0107] like Figure 1 , Figure 3 and Figure 5 As shown, a rear bearing housing cooling channel 4 is formed between the bushing 1 and the rear bearing housing 2, which can cool the bearing assembly installed on the rear bearing housing 2. The rear bearing housing cooling channel 4 is sealed by a sealing ring. The first liquid inlet groove 13 is connected to the first rear bearing housing cooling groove 311, and the first liquid outlet groove 14 is connected to the third rear bearing housing cooling groove 213. The coolant in the first coolant channel 11 enters the first rear bearing housing cooling groove 211 through the first liquid inlet groove 13, and then enters the third front bearing housing cooling groove 213 through the second rear bearing housing cooling groove 212, thus forming the rear bearing housing cooling channel 4.

[0108] like Figure 2 , Figure 4 and Figure 5 As shown, a front bearing housing cooling channel 5 is formed between the bushing 1 and the front bearing housing 3, which can cool the bearing assembly installed on the front bearing housing 3. The front bearing housing cooling channel 5 is sealed by a sealing ring. The second liquid inlet 15 and the third front bearing housing cooling tank 313 are connected. The first front bearing housing cooling tank 311 and the second liquid outlet 16 are connected. The coolant in the first coolant channel 11 and the cooling circulation channel 17 enters the third front bearing housing cooling tank 313 through the second liquid inlet 15, and then enters the first front bearing housing cooling tank 211 from the second front bearing housing cooling tank 311, thus forming the front bearing housing cooling channel 5.

[0109] The coolant enters the first coolant channel 11 through the inlet pipe joint 61 installed on the pipe plate 6, enters the rear bearing housing cooling channel 12 through the first inlet tank 13, and then enters the first coolant channel 11 and the cooling circulation channel 17 through the first outlet tank 14. Then the coolant enters the front bearing housing cooling channel 5 through the second inlet tank 15, and then enters the second coolant channel 12 through the second outlet tank 16. Finally, the cooling cycle is completed through the outlet pipe joint 62 installed on the pipe plate 6.

[0110] like Figure 1 and Figure 2 As shown, a circulation channel sealing block 7 is provided at the end of the cooling circulation channel 17. The form of the circulation channel sealing block 7 is not limited. It can be a pin-embedded seal, a threaded plug seal, a ball-shaped plug seal, or a sealing ring structure. As long as it can form a seal between the end face of the cooling circulation channel 17 and the rear bearing seat 2, it can ensure that the coolant does not leak from the position where the cooling circulation channel 17 and the rear bearing seat 2 are in contact.

[0111] like Figure 5 As shown, the first liquid outlet tank 14 and the second liquid inlet tank 15 are annular tanks, and the first liquid inlet tank 13 and the second liquid outlet tank 16 are arc-shaped tanks.

[0112] In this embodiment of the invention, by setting the first liquid inlet groove 13 and the second liquid outlet groove 16 as arc-shaped grooves, on the one hand, setting the first liquid inlet groove 13 and the second liquid outlet groove 16 as arc-shaped can avoid the impact of large-area slotting on the bushing 1 on the rigidity of the bushing 1. On the other hand, it can also avoid the situation where the first liquid inlet groove 13 and the second liquid outlet groove 16 are connected to the cooling circulation channel 17 when the opening area of ​​the first liquid inlet groove 13 and the second liquid outlet groove 16 is large. {If the first liquid inlet groove 13 and the second liquid outlet groove 16 are set as annular, the above situation will occur. In order to avoid the occurrence of the above situation, the first liquid inlet groove 13 and the second liquid outlet groove 16 are set as arc-shaped}.

[0113] like Figure 1 , Figure 2 and Figure 5 As shown, with the center of the end face of the bushing 1 as the center, the distance from the center of the first coolant flow channel 11 and the cooling circulation flow channel 17 is D1, and the distance from the center of the second coolant flow channel 12 is D2, and D2 > D1, so as to ensure that the first liquid outlet trough 14 and the second liquid inlet trough 15 will not be connected to the second coolant flow channel 17.

[0114] like Figure 1 , Figure 2 and Figure 5 As shown, the depth of the first coolant flow channel 11 and the cooling circulation flow channel 17 on the bushing 1 is L1, and the depth of the second coolant flow channel 12 is L2, and L2>L1, so as to ensure that the second coolant flow channel 12 can communicate with the second outlet tank 16.

[0115] like Figure 5 As shown, the first coolant flow channel 11 and the second coolant flow channel 12 can be arbitrarily distributed along the circumference. They can be adjacent, 180° opposite each other, or arbitrarily separated by several cooling circulation channels 17. Figure 5 This is just a schematic diagram of one possible distribution method.

[0116] The second aspect of this embodiment provides an electric spindle, which includes a motor shaft, a rear bearing, a front bearing, and the aforementioned cooling structure;

[0117] The motor shaft passes through the middle of the cooling structure. The rear bearing is installed in the mounting slot of the rear bearing housing and rotates with the motor shaft. The front bearing is installed in the mounting slot of the front bearing housing and rotates with the motor shaft.

[0118] In any of the above embodiments, the rear bearing is opposite to the rear bearing housing cooling channel 4 in its radial direction;

[0119] The front bearing is opposite the front bearing housing cooling channel 5 structure in its radial direction.

[0120] A third aspect of this invention also provides a machine tool including the electric spindle described above.

[0121] Example 2

[0122] The difference between this embodiment and Embodiment 1 is that:

[0123] like Figure 6 As shown, the first inlet groove 13 can be replaced by a hole that penetrates the first coolant flow channel 11 radially. The upper part of the hole is sealed with a pin, a threaded plug, or a spherical plug, so that the first coolant flow channel 11 is connected to the first rear bearing housing cooling groove 211.

[0124] like Figure 6 and Figure 7 As shown, the first liquid outlet 14 and the second liquid inlet 15 can be replaced by several holes that penetrate the cooling circulation channel 17 radially. The upper part of the holes is sealed with pins, threaded plugs, or spherical plugs, so that the cooling circulation channel 17 is connected to the third front bearing housing cooling channel 313 and the third rear bearing housing cooling channel 213.

[0125] like Figure 7 As shown, the second inlet groove 16 can be replaced by a hole that penetrates the first coolant flow channel 11 radially. The upper part of the hole is sealed with a pin, a threaded plug, or a spherical plug, so that the second coolant flow channel 12 is connected to the first front bearing housing cooling groove 211.

[0126] 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.

[0127] 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. A cooling structure for cooling the spindle core of an electric spindle, characterized in that, The cooling structure includes: A bushing (1) having a first end face and a second end face in its axial direction and an inner circumferential surface between the first end face and the second end face; A rear bearing housing (2) and a front bearing housing (3) are provided for mounting on the first end face side and the second end face side of the bushing (1). The rear bearing housing (2) has an outer circumferential surface that mates with the inner circumferential surface of the bushing after assembly. The front bearing housing (3) has an outer circumferential surface that mates with the inner circumferential surface of the bushing after assembly. A rear bearing housing cooling channel (4) is formed between the inner circumferential surface of the bushing and the outer circumferential surface of the rear bearing housing. A front bearing housing cooling channel (5) is formed between the inner circumferential surface of the bushing and the outer circumferential surface of the front bearing housing. The bushing (1) is further provided with a first coolant channel (11) and a second coolant channel (12) extending in its axial direction. The inlet end of the first coolant channel (11) and the outlet end of the second coolant channel (12) are located on the same side. The first coolant channel (11) connects the rear bearing housing cooling channel (4) and the front bearing housing cooling channel (5), and the second coolant channel (12) connects the front bearing housing cooling channel (5). A rear bearing housing cooling groove (21) is provided on the outer circumferential surface of the rear bearing housing, and the rear bearing housing cooling groove (21) and the inner circumferential surface of the bushing form a rear bearing housing cooling channel (4). A front bearing housing cooling groove (31) is provided on the outer circumferential surface of the front bearing housing, and the front bearing housing cooling groove (31) and the inner circumferential surface of the bushing form the front bearing housing cooling channel (5). The bushing (1) is also provided with a first liquid inlet groove (13), a first liquid outlet groove (14), a second liquid inlet groove (15), and a second liquid outlet groove (16); The inlet end of the first liquid inlet tank (13) is connected to the first coolant flow channel (11), and the outlet end is connected to the rear bearing seat cooling flow channel (4). The inlet end of the first liquid outlet tank (14) is connected to the rear bearing seat cooling flow channel (4), and the outlet end is connected to the first coolant flow channel (11). The inlet end of the second liquid inlet tank (15) is connected to the first coolant flow channel (11), and the outlet end is connected to the front bearing housing cooling flow channel (5). The inlet end of the second liquid outlet tank (16) is connected to the front bearing housing cooling flow channel (5), and the outlet end is connected to the second coolant flow channel (12).

2. The cooling structure according to claim 1, characterized in that, The rear bearing housing cooling groove (21) includes a first rear bearing housing cooling groove (211), a second rear bearing housing cooling groove (212), and a third rear bearing housing cooling groove (213) adjacent to each other along the axial direction of the outer peripheral surface of the rear bearing housing. The second rear bearing housing cooling groove (212) is used to connect the first rear bearing housing cooling groove (211) and the third rear bearing housing cooling groove (213), and the groove depth of the second rear bearing housing cooling groove (212) is less than the groove depth of the first rear bearing housing cooling groove (211) and the groove depth of the third rear bearing housing cooling groove (213). The first rear bearing housing cooling groove (211) is located near the inlet end of the first coolant flow channel (11) relative to the third rear bearing housing cooling groove (213). The first inlet groove (13) connects the first rear bearing housing cooling groove (211) and the first coolant flow channel (11), and the first outlet groove (14) connects the third rear bearing housing cooling groove (213) and the first coolant flow channel (11). The front bearing housing cooling groove (31) includes a first front bearing housing cooling groove (311), a second front bearing housing cooling groove (312), and a third front bearing housing cooling groove (313) arranged adjacent to each other along the axial direction of the outer peripheral surface of the front bearing housing. The second front bearing housing cooling groove (312) is used to connect the first front bearing housing cooling groove (311) and the third front bearing housing cooling groove (313), and the groove depth of the second front bearing housing cooling groove (312) is less than the groove depth of the first front bearing housing cooling groove (311) and the groove depth of the third front bearing housing cooling groove (313). The first front bearing housing cooling groove (311) is arranged away from the outlet end of the second coolant channel (12) relative to the third front bearing housing cooling groove (313). The second inlet groove (15) connects the first front bearing housing cooling groove (311) and the first coolant channel (11), and the second outlet groove (16) connects the third front bearing housing cooling groove (313) and the second coolant channel (12).

3. The cooling structure according to claim 2, characterized in that, The first liquid inlet groove (13) and the second liquid outlet groove (16) are arc-shaped grooves opened along the circumferential direction of the bushing (1), and the first liquid outlet groove (14) and the second liquid inlet groove (15) are annular grooves opened along the circumferential direction of the bushing (1). The first rear bearing housing cooling groove (211) and the third rear bearing housing cooling groove (213) are annular grooves opened along the circumferential direction of the rear bearing housing (2), and the second rear bearing housing cooling groove (212) is an arc-shaped groove opened along the circumferential direction of the rear bearing housing (2). The first front bearing housing cooling groove (311) and the third front bearing housing cooling groove (313) are annular grooves opened along the circumferential direction of the front bearing housing (3), and the second front bearing housing cooling groove (312) is an arc-shaped groove opened along the circumferential direction of the front bearing housing (3).

4. The cooling structure according to claim 3, characterized in that, The bushing (1) is also provided with a plurality of cooling circulation channels (17) extending along its axial direction, and the plurality of cooling circulation channels (17) are evenly distributed in the circumferential direction of the bushing (1). The cooling circulation channel (17) has a first end near the rear bearing seat (2) and a second end near the front bearing seat (3) in the axial direction of the bushing (1). The cooling circulation channel (17) is connected to the first liquid outlet groove (14) near the first end and to the second liquid inlet groove (15) near the second end.

5. The cooling structure according to claim 4, characterized in that, The minimum distance between the location of the first coolant flow channel (11) and the cooling circulation flow channel (17) and the axis of the bushing (1) is D1; The minimum distance between the location of the second coolant flow channel (12) and the axis of the bushing (1) is D2; Where D2 > D1; The length of the first coolant flow channel (11) and the cooling circulation flow channel (17) in the axial direction of the bushing (1) is L1; The length of the second coolant channel (12) in the axial direction of the bushing (1) is L2; Where L2 > L1.

6. The cooling structure according to any one of claims 1-5, characterized in that, The cooling structure also includes: Pipeline plate (6), the pipeline plate (6) is connected to the rear bearing seat (2), and the pipeline plate (6) is provided with inlet pipe joint (61) and outlet pipe joint (62). The rear bearing housing (2) is provided with an inlet connecting groove (214) and an outlet connecting groove (215) along its axial direction. The inlet pipe connector (61) is connected to the inlet end of the first coolant flow channel (11) through the inlet connecting groove (214), and the outlet pipe connector (62) is connected to the outlet end of the second coolant flow channel (12) through the outlet connecting groove (215).

7. The cooling structure according to claim 4, characterized in that, The first coolant flow channel (11), the second coolant flow channel (12), and the cooling circulation flow channel (17) all have openings formed on the first end face side of the bushing (1); The opening of the first coolant flow channel (11) serves as the inlet, and the opening of the second coolant flow channel (12) serves as the outlet. The opening of the cooling circulation channel (17) is provided with a sealing block (7).

8. The cooling structure according to claim 1, characterized in that, The inner circumferential surface of the bushing is provided with a bushing mounting slot (18) through which the motor shaft core passes, the inner circumferential surface of the rear bearing housing is provided with a rear bearing housing mounting slot (22) through which the motor shaft core passes, and the inner circumferential surface of the front bearing housing is provided with a front bearing housing mounting slot (32) through which the motor shaft core passes. The bushing mounting slot (18) is connected to the rear bearing housing mounting slot (22) and the front bearing housing mounting slot (32) at its two ends in the axial direction, respectively.

9. An electric spindle, characterized in that, Includes a motor shaft, a rear bearing, a front bearing, and a cooling structure as described in any one of claims 1-8; The motor shaft passes through the middle of the cooling structure, the rear bearing is installed in the mounting slot of the rear bearing seat and rotates with the motor shaft, and the front bearing is installed in the mounting slot of the front bearing seat and rotates with the motor shaft.

10. The electric spindle according to claim 9, characterized in that, The rear bearing is opposite the rear bearing housing cooling channel (4) in its radial direction; The front bearing is opposite the front bearing housing cooling channel (5) structure in its radial direction.

11. A machine tool, characterized in that, Includes the electric spindle as described in claim 9 or 10.

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