An external circulation cooling device for a machine tool spindle

Abstract

The utility model discloses a kind of external circulation cooling devices for lathe spindle, it is related to external circulation cooling technical field.The device includes spindle, shaft sleeve, shaft sleeve box and detachable sealing assembly, shaft sleeve is covered in the outside of spindle, its outer wall is equipped with mutually isolated upper cooling flow channel and lower cooling flow channel, shaft sleeve box is covered in the outside of shaft sleeve, its two end side wall and intermediate position are respectively equipped with first cooling interface and second cooling interface, cooling flow channel is located in the closed passage formed between the outer wall of shaft sleeve and the inner wall of shaft sleeve box, cooling flow channel can be designed as the groove annular structure or groove helical structure with communicating passage, realize efficient bidirectional circulation cooling by optimizing cooling interface layout.Sealing assembly is by sealing ring and screw connection etc., ensure the reliable sealing and convenient assembly between shaft sleeve and shaft sleeve box, the structure effectively improves the heat dissipation efficiency and sealing property of spindle system, and it is convenient to maintain.

Description

Technical Field

[0001] This utility model relates to the field of external circulation cooling technology for spindles, specifically an external circulation cooling device for machine tool spindles. Background Technology

[0002] As the core component of a high-speed precision transmission system, the thermal stability of the machine tool spindle is directly related to the machining accuracy, dynamic performance and service life of the whole machine. Under high-speed and heavy-load operating conditions, the spindle and bushing will generate a lot of heat due to friction. If the heat cannot be dissipated in time and effectively, it will cause thermal deformation of the spindle, which will lead to machining errors or even spindle failure, affecting the performance of the equipment.

[0003] Currently, most machine tool spindles use external circulation cooling, which dissipates heat through cooling channels arranged around the outer ring of the bushing. Traditional designs typically have the following significant problems: Uneven cooling effect: The area of ​​the machine tool spindle near the coolant inlet has good heat dissipation effect, while the area near the coolant outlet has poor heat dissipation effect, resulting in uneven heat dissipation of the spindle and affecting the accuracy of the equipment.

[0004] Replacing the seals is cumbersome: the seals are mostly installed at the interface between the bushing and the cooling pipes and channels. When replacing them, the spindle and bushing must be removed as a whole. Since the spindle and bushing are heavy, it takes several hours each time, which reduces the utilization rate of the equipment and increases the operating costs of the enterprise.

[0005] Therefore, existing external circulation cooling structures for machine tool spindles have significant limitations in terms of cooling effect and ease of disassembly, making it difficult to meet the stringent thermal stability requirements of modern high-precision, high-speed machine tools. There is an urgent need for a cooling structure that can achieve efficient, uniform, and convenient cooling to improve the practicality of external circulation cooling devices for spindles. Summary of the Invention

[0006] The purpose of this invention is to provide an external circulation cooling device for machine tool spindles, which aims to solve the problems of uneven spindle cooling effect and time-consuming and laborious replacement of seals in the prior art.

[0007] To achieve the above objectives, this utility model provides the following device: an external circulation cooling device for a machine tool spindle, comprising a spindle, a bushing, a bushing housing, and a sealing assembly, wherein... The bushing covers the outside of the spindle, and its outer wall is provided with upper and lower cooling channels that are isolated from each other. The independent channels can improve the heat dissipation effect. The bushing housing covers the outside of the bushing. The two end side walls of the bushing housing are provided with first cooling interfaces, and the middle part is provided with at least two second cooling interfaces. The first cooling interfaces and the second cooling interfaces are respectively connected to the upper cooling channel and the lower cooling channel. The upper cooling channel and the lower cooling channel are located between the outer wall of the bushing and the inner wall of the bushing housing to provide a flow path for the coolant. The sealing assembly connects the bushing to the bushing housing via a detachable sealing assembly, ensuring the sealing performance between the bushing and the bushing housing while facilitating subsequent disassembly and maintenance of the device.

[0008] The upper and lower cooling channels are several groove-shaped annular structures, with cooling channels opened between adjacent annular structures. The first cooling interface is the water outlet of the upper cooling channel and the water inlet of the lower cooling channel, and the second cooling interface is the water inlet of the upper cooling channel and the water outlet of the lower cooling channel. This allows the coolant to flow from bottom to top in both the upper and lower cooling channels. The groove-shaped annular structure ensures that the coolant is in full contact with all parts of the bushing, improving the uniformity of heat dissipation.

[0009] Both the upper and lower cooling channels are spiral-shaped structures. The first cooling interface is the water inlet, and the second cooling interface is the water outlet. This allows the coolant to flow in from both water inlets, pass through the spiral cooling channels, and then exit from the middle water outlet. The spiral cooling channels ensure that the coolant flows along a predetermined path, improving the overall heat dissipation effect.

[0010] A groove is provided in the middle of the bushing, and a first sealing ring is installed in the groove, so that the coolant in the upper cooling channel and the coolant between the lower cooling channel can circulate independently, thereby improving the heat dissipation effect.

[0011] The sealing assembly includes seals located at both ends of the bushing, a second sealing ring between the seals and the bushing housing, and a third sealing ring between the seals and the bushing. The seals are threadedly connected to the bushing. The second and third sealing rings are annular structures, which ensure full coverage of the sealing surface and prevent local leakage.

[0012] The second sealing ring has a circular cross-section. The outer circumference of the seal is provided with a semi-circular groove that matches the second sealing ring. The second sealing ring is partially placed inside the semi-circular groove. The circular cross-section structure can tightly fit the gap between the seal and the bushing housing when under pressure, improving the sealing reliability. The semi-circular groove provides positioning and limiting for the second sealing ring, preventing the sealing ring from falling off or shifting during device operation.

[0013] The third sealing ring has two flat surfaces on both sides, which fit tightly against one side of the bushing and the other side of the seal. The flat surfaces can increase the sealing contact area, improve the sealing effect, and prevent coolant from leaking from the thread gap between the seal and the bushing.

[0014] The bushing has protrusions at both ends, and external threads on the protrusions. One end of the seal has a connecting groove that matches the protrusions, and the inner wall of the connecting groove has an internal thread that matches the external thread. The matching of the protrusions and the connecting groove can achieve precise positioning and assembly of the bushing and the seal, avoiding eccentricity during assembly. Compared with other connection methods, the threaded connection method has adjustability and tightness. The third sealing ring can be further compressed by tightening the seal, which can improve the sealing effect and facilitate disassembly and maintenance.

[0015] The bushing housing has first connecting holes at both ends, and the seal has a second connecting hole on the side away from the bushing that matches the first connecting hole. The first and second connecting holes provide an installation and fixing interface for the bushing housing and the seal, preventing the seal from loosening during equipment operation and increasing the reliability and stability of the connection.

[0016] Compared with the prior art, the beneficial effects of this utility model are: Improve the uniformity of spindle heat dissipation: The symmetrical cooling channel structure can simultaneously take into account the heat dissipation effect at both ends and the middle of the spindle. This structure can balance the coolant flow and heat exchange time in different areas of the spindle, avoiding the problem of excessive cooling in the inlet area and insufficient cooling in the outlet area when using traditional unidirectional cooling. This makes the temperature of each part of the spindle tend to be uniform, effectively ensuring the machining accuracy of the machine tool.

[0017] Simplified seal replacement process: The sealing assembly adopts a detachable design. Through the threaded connection between the seal and the bushing and the screw connection between the bushing housing and the seal, it is possible to replace the seal without removing the entire spindle and bushing. Simply remove the screw between the bushing housing and the seal, rotate the seal to separate it from the bushing, and then remove the seal separately. This facilitates the replacement of the second and third seals and significantly shortens the replacement time. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the external circulation cooling device for machine tool spindles according to the present invention. Figure 2 This is a schematic diagram of the structure of a main shaft, bushing, and seal according to the present invention; Figure 3 This is a structural schematic diagram of a bushing housing according to the present invention; Figure 4 This is a schematic diagram of a main shaft and bushing structure according to the present invention; Figure 5 This is a schematic diagram of a sealing component structure according to the present invention; Figure 6 This is a schematic diagram of the structure of a second sealing ring and a third sealing ring according to the present invention; Figure 7This is a schematic diagram of a bushing structure according to another embodiment of the present invention.

[0019] Labels in the diagram: 1. Spindle; 2. Bushing; 21. Upper cooling channel; 22. Lower cooling channel; 23. First sealing ring; 24. External thread; 25. Cooling channel; 3. Bushing housing; 31. First cooling interface; 32. Second cooling interface; 33. First connecting hole; 4. Seal; 41. Second sealing ring; 42. Third sealing ring; 43. Second connecting hole; 44. Internal thread; 45. Semi-circular groove. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Example 1: As Figure 1 As shown, this embodiment provides an external circulation cooling device for machine tool spindles, which mainly consists of a spindle 1, a bushing 2, a bushing housing 3, and a sealing assembly.

[0022] like Figure 2 As shown, the outer ring of the bushing 2 is evenly provided with several cooling channels. The cooling channels are groove-shaped annular structures. Cooling channels 25 are opened between adjacent cooling channels. The coolant flows in the cooling channels and flows into the adjacent cooling channels through the cooling channels 25, ensuring that the coolant is in full contact with all parts of the bushing 2. The bushing 2 is equipped with a high-speed rotating spindle 1. The spindle 1 generates heat when it is working, and the heat is cooled by the coolant in the cooling channels.

[0023] like Figure 4 As shown, the bushing 2 is coaxially installed inside the bushing housing 3. The bushing 2 has protrusions at both ends, and external threads 24 are provided on the protrusions. The bushing 2 also has seals 4 at both ends. The seals 4 are used to connect the bushing 2 and the bushing housing 3. The side of the seal 4 near the bushing 2 has a connecting groove that matches the protrusion. The connecting groove has an internal thread 44 that matches the external thread 24. The connecting groove of the seal 4 is fitted onto the protrusion of the bushing 2. By rotating the seal 4, the external thread 24 on the protrusion of the bushing 2 is fixedly connected to the internal thread 44 on the seal 4, ensuring the stability of the connection between the two.

[0024] A first sealing ring 23 is provided in the middle of the bushing 2. The first sealing ring 23 divides the cooling channel into an upper cooling channel 21 and a lower cooling channel 22, so that the upper cooling channel 21 and the lower cooling channel 22 circulate independently, thereby improving the heat dissipation effect. A third sealing ring 42 is installed between the bushing 2 and the seal 4. The two sides of the third sealing ring 42 are flat. One side of the flat side is attached to one end of the bushing 2, and the other side is attached to one end of the seal 4. By rotating the seal 4, the third sealing ring 42 is squeezed and fixed. The third sealing ring 42 is used to perform the first sealing function between the bushing housing 3 and the seal 4, preventing the coolant from leaking through the gap between the bushing housing 3 and the seal 4, as well as the gap between the bushing 2 and the seal 4.

[0025] like Figure 5-6 As shown, the outer periphery of the seal 4 is provided with a semi-circular groove 45, and an annular second sealing ring 41 is fitted on the semi-circular groove 45. The cross-section of the second sealing ring 41 is a circular structure that matches the semi-circular groove 45. The semi-circular groove 45 plays a limiting role for the second sealing ring 41. A part of the second sealing ring 41 is inserted into the semi-circular groove 45, which performs a second sealing function on the bushing housing 3 and the seal 4, further preventing coolant from leaking through the gap between the bushing housing 3 and the seal 4.

[0026] like Figure 3 As shown, the bushing housing 3 has first connecting holes 33 circumferentially opened at both ends, and the sealing member 4 has a second connecting hole 43 corresponding to the first connecting hole 33 on the side connected to the bushing housing 3. The first connecting hole 33 and the second connecting hole 43 are threaded holes, and the sealing member 4 is fixedly connected to the bushing housing 3 by screws.

[0027] The bushing housing 3 has a first cooling port 31 at each end and two second cooling ports 32 in the middle. The first cooling ports 31 are the water outlet of the upper cooling channel 21 and the water inlet of the lower cooling channel 22, respectively. The second cooling ports 32 are the water inlet of the upper cooling channel 21 and the water outlet of the lower cooling channel 22, respectively. This allows the coolant to flow from bottom to top in both the upper cooling channel 21 and the lower cooling channel 22. After filling the bottom cooling channel, the coolant will spread upwards through the cooling channel 25 layer by layer, making full contact with all parts of the bushing 2. This ensures that the coolant passes evenly through the bushing 2 and dissipates heat from the spindle 1.

[0028] During assembly, the first sealing ring 23 is installed on the groove in the middle of the bushing 2, the third sealing ring 42 is fitted onto the protrusion on one side of the bushing 2, and the second sealing ring 41 is fitted into the semi-circular groove 45 of the sealing element 4, laying the foundation for its sealing function.

[0029] Align the connecting groove of the seal 4 with the protrusion at one end of the bushing 2 and insert it. Tighten the seal 4 by rotating it until it is completely fixed. At this time, the third sealing ring 42 is squeezed into place to prevent coolant from seeping out from the gap between the seal 4 and the bushing housing 3 and the gap between the seal 4 and the bushing 2.

[0030] Next, insert the installed bushing 2 and seal 4 from one side of the bushing housing 3, align the first connecting hole 33 on the bushing housing 3 with the second connecting hole 43 on the seal 4, and tighten the screws to fix it. At this time, the second sealing ring 41 is installed in place. The second sealing ring 41 can prevent coolant from seeping out from the gap between the seal 4 and the bushing housing 3. Then install the seal 4 on the other side in the same way so that both sides of the bushing 2 can be sealed and fixed, ensuring the overall sealing and structural integrity.

[0031] After installation, connect the water inlet ports on both sides and the water outlet port in the middle of the bushing housing 3 to the corresponding positions of the cooling device. The first cooling port 31 is the water outlet port of the upper cooling channel 21 and the water inlet port of the lower cooling channel 22, respectively. The second cooling port 32 is the water inlet port of the upper cooling channel 21 and the water outlet port of the lower cooling channel 22, respectively.

[0032] During the cooling cycle, the coolant flows from bottom to top in both the upper cooling channel 21 and the lower cooling channel 22. After filling the bottom cooling channel, the coolant spreads upward through the cooling channel 25 layer by layer, and finally flows out from the top of the upper cooling channel 21 and the lower cooling channel 22. The upward flow of the coolant ensures sufficient contact between the coolant and each part of the bushing 2, realizing heat exchange.

[0033] By dividing the bushing 2 into two parts, the heat dissipation of the spindle 1 can be accelerated, and the uneven heat dissipation effect of different parts of the spindle 1 caused by the temperature rise of the coolant when it passes through the cooling channel can be reduced.

[0034] Example 2: As Figure 7 As shown, this embodiment changes the structure of the cooling channel and the connection method of the first cooling interface 31 and the second cooling interface 32 based on embodiment 1, so that both the upper cooling channel 21 and the lower cooling channel 22 are groove-shaped spiral structures. The first cooling interface 31 is a water inlet interface and the second cooling interface 32 is a water outlet interface. The spiral cooling channel ensures that the coolant flows along a predetermined route with less resistance and faster flow rate, thereby improving the overall heat dissipation effect.

[0035] During coolant circulation, the coolant flows in from the first cooling ports 31 at both ends of the bushing housing 3 and enters the closed spiral channel formed by the cooling flow channel on the outer wall of the bushing 2 and the inner wall of the bushing housing 3. The coolant at both ends flows towards the middle and finally converges and flows out at the second cooling port 32 in the middle of the bushing housing 3, realizing heat exchange and forming a highly efficient closed-loop cooling cycle. This fully absorbs the heat generated by the bearing inside the bushing 2, preventing thermal deformation of the main shaft 1 and thus affecting the overall operation of the device. Simultaneous heat dissipation from both sides can improve the uniformity of heat dissipation.

[0036] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An external circulation cooling device for machine tool spindles, characterized in that... It includes a spindle, bushing, bushing housing, and sealing assembly, among which, The bushing covers the outside of the spindle, and its outer wall is provided with upper and lower cooling channels that are isolated from each other. The bushing housing covers the outside of the bushing. The two end side walls of the bushing housing are provided with first cooling interfaces, and the middle part is provided with at least two second cooling interfaces. The first cooling interfaces and the second cooling interfaces are respectively connected to the upper cooling channel and the lower cooling channel. The upper cooling channel and the lower cooling channel are located between the outer wall of the bushing and the inner wall of the bushing housing. The sealing assembly connects the bushing to the bushing housing in a sealed manner via a detachable sealing assembly.

2. The external circulation cooling device for a machine tool spindle according to claim 1, characterized in that: Both the upper and lower cooling channels are several groove-shaped annular structures, with cooling channels opened between adjacent annular structures. The first cooling interface is the water outlet of the upper cooling channel and the water inlet of the lower cooling channel, and the second cooling interface is the water inlet of the upper cooling channel and the water outlet of the lower cooling channel.

3. The external circulation cooling device for machine tool spindles according to claim 1, characterized in that: Both the upper and lower cooling channels are groove-shaped spiral structures. The first cooling interface is a water inlet interface, and the second cooling interface is a water outlet interface.

4. The external circulation cooling device for a machine tool spindle according to claim 1, characterized in that: The bushing has a groove in the middle, and a first sealing ring is installed in the groove.

5. The external circulation cooling device for a machine tool spindle according to claim 1, characterized in that: The sealing assembly includes sealing elements disposed at both ends of the bushing, a second sealing ring between the sealing elements and the bushing housing, and a third sealing ring between the sealing elements and the bushing. The sealing elements and the bushing are threadedly connected, and the second and third sealing rings are annular structures.

6. The external circulation cooling device for a machine tool spindle according to claim 5, characterized in that: The second sealing ring has a circular cross-section, and the outer periphery of the sealing element is provided with a semi-circular groove that matches the second sealing ring. The second sealing ring is partially placed inside the semi-circular groove.

7. The external circulation cooling device for a machine tool spindle according to claim 5, characterized in that: The third sealing ring has two flat surfaces on both sides, which are in close contact with one side of the bushing and the other side of the seal, respectively.

8. An external circulation cooling device for a machine tool spindle according to claim 5, characterized in that: The bushing has protrusions at both ends, and external threads are provided on the protrusions. One end of the seal has a connecting groove that matches the protrusions, and the inner wall of the connecting groove has an internal thread that matches the external thread.

9. An external circulation cooling device for a machine tool spindle according to claim 5, characterized in that: The bushing housing has first connecting holes at both ends, and the sealing element has a second connecting hole on the side away from the bushing that matches the first connecting holes.

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