High-efficiency heat exchange and heat dissipation spindle structure

Abstract

The application discloses a high-efficiency heat-exchange heat-dissipation spindle structure, which comprises a spindle body, wherein the spindle body at least comprises a shell, a plurality of heat-exchange pipes and a cooling water channel structure are arranged in the shell; the heat-exchange pipes are used for absorbing heat at positions of bearings corresponding to the shell, and a to-be-cooled part is formed in the middle of the shell; the cooling water channel structure is used for absorbing heat of the shell, and absorbs heat of working medium in the heat-exchange pipes by passing through the to-be-cooled part; the heat-exchange pipes and the cooling water channel structure simultaneously absorb heat and reduce temperature of the shell near the bearing positions; working medium in the heat-exchange pipes is vaporized and flows to the middle position to form the to-be-cooled part; cooling water of the cooling water channel structure passes through the middle position of the shell, absorbs heat of the to-be-cooled part, and makes working medium in the heat-exchange pipes condense and flow back to two ends to participate in heat dissipation work again, so that the bottleneck problem that heat in the interior of the shell is difficult to conduct to the exterior when the shell is externally water-cooled in the prior art is solved.

Description

Technical Field

[0001] This invention belongs to the technical field of spindle heat dissipation structure, specifically a high-efficiency heat exchange heat dissipation spindle structure. Background Technology

[0002] The high-speed spindle unit is the most critical component of a high-speed machining tool. During operation, heat is generated inside the spindle, and the higher the spindle speed, the greater the heat. The accumulation of heat can cause slight thermal expansion of metal parts, leading to spindle imbalance and increased errors in the machining of parts. Currently, water cooling is mainly used to dissipate heat from the spindle housing, but this method has low heat dissipation efficiency.

[0003] In addition, the heat inside the housing is difficult to dissipate and is mainly concentrated at the bearing. The bearing generates a lot of heat due to friction during high-speed rotation, which will cause a temperature difference between the inner and outer rings of the bearing, resulting in an increase in the gap between the balls. This will also lead to a decrease in the spindle balance and affect the machining accuracy. Summary of the Invention

[0004] The purpose of this invention is to provide a high-efficiency heat exchange and heat dissipation spindle structure to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A high-efficiency heat exchange and heat dissipation spindle structure includes a spindle body, the spindle body including at least a housing, and the housing is provided with a plurality of heat exchange pipes and a cooling water circuit structure.

[0007] The heat exchange tube is used to absorb heat at the bearing position corresponding to the housing and forms a cooling section in the middle of the housing;

[0008] The cooling water circuit structure is used to absorb heat from the shell and absorbs heat from the working fluid in the heat exchange tubes in the section to be cooled.

[0009] A further technical solution is that, along the length of the shell, a plurality of protruding ribs are integrally formed on the outer periphery of the shell, and the protruding ribs are arranged in a ring around the outer periphery of the shell;

[0010] Each rib is provided with several first grooves, the shell is provided with a second groove corresponding to the first groove, and a third groove extending in the same direction as the second groove. The first groove and the second groove are combined to form a limiting channel. The heat exchange tube is inserted into the limiting channel, and the heat exchange tube is in full contact with the inner wall of the limiting channel, that is, the inner wall of the third groove.

[0011] A further technical solution is to fix a dust cover on the rib.

[0012] A further technical solution is that a limiting channel is formed between the protruding rib at the foremost end and the shell as an entrance, and a sealing element is provided at the entrance.

[0013] In a further technical solution, the spindle body also includes a rotating shaft, which passes through the housing and is connected to the front bearing assembly and the rear bearing assembly respectively. The housing is provided with a pre-tightening assembly, which acts on the front bearing assembly and / or the rear bearing assembly to counteract the gap caused by heat generated during operation.

[0014] In a further technical solution, the rear bearing assembly includes at least two ball bearings stacked one after the other;

[0015] The preload structure includes a cylindrical fixing protrusion inside the housing. Several springs are provided at the end of the fixing protrusion along its circumferential direction. An outer preload ring is provided on the end face of the fixing protrusion. The outer preload ring is clearance-fitted with the inner wall of the housing, and the end face of the outer preload ring is provided with an abutting part. The abutting part abuts against the outer ring of one of the ball bearings.

[0016] The inner ring of the ball bearing is connected to the shaft, and the shaft is provided with an inner preload ring. The inner preload ring contacts the inner ring of the same ball bearing, and the inner ring of the other ball bearing contacts the rear end cover on the housing.

[0017] The beneficial effects of this invention are:

[0018] The heat generated by the spindle during operation is mainly diffused outward from the bearings. The heat exchange tubes cover the housing corresponding to the front and rear bearings. During operation, the heat exchange tubes and cooling water circuit structure simultaneously absorb heat and cool the housing near the bearings. The working fluid in the heat exchange tubes vaporizes and flows towards the center to form the cooling section. The cooling water in the cooling water circuit structure passes through the middle of the housing, absorbs the heat from the cooling section, and causes the working fluid in the heat exchange tubes to condense and liquefy and flow back to both ends to participate in heat dissipation again. The heat exchange tubes and cooling water circuit structure form a synergistic heat dissipation mechanism of "internal heat absorption and external heat dissipation", which solves the bottleneck problem that it is difficult to conduct internal heat to the outside when relying solely on external water cooling of the housing.

[0019] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0020] Figure 1 : External structure diagram of the spindle of the present invention.

[0021] Figure 2 : Disassembly diagram of the heat exchange tube in the spindle of this invention.

[0022] Figure 3 : Cross-sectional structural diagram of the main shaft of the present invention.

[0023] Figure 4 : A structural diagram of the first cooling water circuit of the present invention.

[0024] Figure 5 : The second cooling water circuit structure diagram of the present invention.

[0025] Figure 6 : Cross-sectional structural diagram of the heat exchange tube arrangement of the present invention.

[0026] Reference numerals: 1-Spindle body, 11-Housing, 111-Fixing protrusion, 112-Rear end cover, 12-Rib, 131-Third groove, 132-Limiting channel, 14-Dust cover, 151-Inlet, 152-Seal, 16-Shaft, 17-Front bearing assembly, 18-Rear bearing assembly, 181-Outer ring, 182-Inner ring, 19-Preload assembly, 191-Spring, 192-Outer preload ring, 193-Contact part, 194-Inner preload ring, 2-Heat exchange pipe, 3-Cooling water circuit structure. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0028] Please refer to Figure 1-6 ;

[0029] The spindle structure described in this invention aims to improve heat dissipation and enhance spindle stability. Specifically, it includes a spindle body 1, which includes at least a housing 11. It should be noted that, in addition to the housing 11, the spindle body 1 must also have necessary parts that can realize the basic functions of the spindle, such as bearings and a rotating shaft 16. This embodiment does not improve the structure of the remaining parts, and will not be described in detail here. For specific implementations, please refer to the existing technology.

[0030] Furthermore, referring to Figure 1 The housing 11 is equipped with several heat exchange tubes 2 and a cooling water circuit structure 3. The heat exchange tubes 2 are preferably heat pipes, which are filled with a phase change working fluid (such as ammonia, ethanol or deionized water) and maintain a certain vacuum. When the spindle rotates at high speed and the internal temperature of the housing 11 rises, the evaporation section of the heat exchange tube 2 absorbs heat and the internal working fluid rapidly vaporizes. The vaporized working fluid moves to the condensation section of the heat exchange tube 2 under the action of a small pressure difference, and condenses into a liquid after releasing latent heat in the condensation section. The liquid working fluid then flows back to the evaporation section through the capillary structure in the tube. This cycle is repeated to achieve efficient heat transfer. This heat exchange process utilizes the latent heat of phase change of the working fluid, and its heat transfer efficiency is much higher than that of ordinary metal heat conduction. The heat transfer coefficient can reach hundreds to thousands of times that of pure copper.

[0031] In addition, since the number of heat exchange tubes 2 is limited and cannot cover all the positions outside the spindle, the heat exchange tubes 2 are only responsible for heat dissipation of a part of it. However, the spindle generates a lot of heat when it is working. Therefore, a second-stage heat dissipation is designed, that is, a cooling water channel structure 3 is provided inside the housing 11, which covers the inside of the housing 11 in all directions.

[0032] The heat generated by the spindle during operation is mainly diffused outward from the bearings. The heat exchange tube 2 covers the housing 11 corresponding to the front and rear bearings. During operation, the heat exchange tube 2 and the cooling water circuit structure 3 simultaneously absorb heat and cool the housing 11 near the bearings. The working fluid in the heat exchange tube 2 vaporizes and flows to the middle to form a section to be cooled. The cooling water in the cooling water circuit structure 3 passes through the middle of the housing 11, absorbs the heat of the section to be cooled, and causes the working fluid in the heat exchange tube 2 to condense and liquefy and flow back to the heat absorption end to participate in heat dissipation again. The heat exchange tube 2 and the cooling water circuit structure 3 form a synergistic heat dissipation mechanism of "internal heat absorption and external heat dissipation", which solves the bottleneck problem that it is difficult for internal heat to be conducted to the outside when the housing 11 is cooled by external water alone.

[0033] It should be noted that the heat exchange tubes at the same location are a single, integral structure. The liquid working fluid is located at both ends to absorb the heat from the bearing. After vaporization, it moves towards the middle to enter the cooling section to release heat. After liquefaction again, it flows back to both ends.

[0034] Another option is to use two separate heat exchange tubes at the same location, with their ends spaced apart and independent of each other. In this case, one end of the two heat exchange tubes corresponds to the position of the front and rear bearings of the main shaft, and the other end extends towards the middle and is located in the cooling section. One end absorbs heat and vaporizes, then flows to the other end. After releasing heat, it flows back to the heat-absorbing end, and so on in a cycle.

[0035] For specific cooling water circuit details, please refer to... Figures 4-6 Specifically, water enters through the first inlet and flows out through the first outlet, then enters through the second inlet and flows out through the second inlet, passing through the entire shell.

[0036] The present invention further describes the installation method of the heat exchange tube 2, see reference. Figure 2 ;

[0037] Along the length of the shell 11, a plurality of raised ribs 12 are integrally formed on the outer periphery of the shell 11. The raised ribs 12 are arranged in a ring around the outer periphery of the shell 11. Each raised rib 12 is provided with a plurality of first grooves. The shell 11 is provided with a second groove corresponding to the first groove, and a third groove 131 extending in the same direction as the second groove. The first groove and the second groove combine to form a limiting channel 132. It should be noted that each raised rib 12 forms a limiting channel 132 with the shell 11. The axially adjacent limiting channels 132 are connected through the third groove 131. The heat exchange tube 2 passes through the limiting channel 132, and the heat exchange tube 2 is in full contact with the inner wall of the limiting channel 132, that is, the inner wall of the third groove 131. A heat exchange tube 2 is limited by multiple limiting channels 132 to avoid the edge warping, so that the heat exchange tube 2 can maintain contact with the shell 11. Multiple heat exchange tubes 2 are distributed in a ring array on the outer periphery of the shell 11.

[0038] In addition, the rib 12 not only serves to strengthen the structure, but more importantly, the heat from the shell 11 can also be transferred to the rib 12, increasing the contact area of ​​the heat exchange tube 2.

[0039] Preferably, thermal grease can be applied in advance to the limiting channel 132 and the third groove 131 to improve the thermal conductivity.

[0040] Furthermore, a dust cover 14 is fixed on the rib 12. The dust cover 14 can be a single arc-shaped cover plate covering the top of multiple ribs 12, or it can be a segmented cover plate covering a local area of ​​each rib 12. The dust cover 14 is fixed to the rib 12 by screws, clips or welding. The function of the dust cover 14 is to prevent impurities such as chips, dust, and oil mist in the external environment from entering the limiting channel 132 and the area of ​​the heat exchange tube 2, and to prevent impurities from depositing on the surface of the heat exchange tube 2 to form a heat insulation layer, thereby ensuring the long-term stable operation of the heat dissipation structure.

[0041] A seal 152 is provided at the entrance 151 of the limiting channel 132 formed between the foremost protruding rib 12 and the housing 11. The seal 152 is preferably a sealing screw to prevent dust, debris or coolant from entering.

[0042] The present invention also proposes a pre-tightening structure, referring to Figure 3 The rotating shaft 16 passes through the housing 11 and is connected to the front bearing assembly 17 and the rear bearing assembly 18 respectively. The housing 11 is provided with a pre-tightening assembly 19, which acts on the front bearing assembly 17 and / or the rear bearing assembly 18 to counteract the gap caused by heat generated during operation.

[0043] During high-speed operation of the spindle (speeds can reach tens of thousands to hundreds of thousands of revolutions per minute), high-speed friction occurs between the bearing rolling elements (balls or rollers) and the raceways of the inner and outer rings 181, generating a large amount of heat. Due to the uneven distribution of heat, the temperature of the inner ring 182 (which is in direct contact with the shaft 16) is usually higher than that of the outer ring 181 (which is in contact with the housing 11), resulting in: the thermal expansion of the inner ring 182 being greater than that of the outer ring 181; the balls themselves also undergo thermal expansion, leading to an increase in the radial and axial clearance of the bearing, a change in the movement trajectory of the balls within the raceway, and a shift in the rotation center of the shaft 16, thereby causing unbalanced vibration of the spindle, ultimately resulting in a decrease in the dimensional accuracy and surface quality of the machined parts; the preload structure can dynamically preload the bearing, maintaining the preload force of the bearing and eliminating clearance, thus improving stability. Of course, this preload structure can be set in one or both of the front bearing assembly 17 and the rear bearing assembly 18, depending on the specific circumstances.

[0044] The following explanation will take bearing assembly 18 as an example;

[0045] The rear bearing assembly 18 includes at least two ball bearings stacked one in front of the other;

[0046] The preload structure includes a cylindrical fixing protrusion 111 inside the housing 11. The cylindrical fixing protrusion 111 is integrally formed with the housing 11, and a step is formed between its end and the wall of the housing 11. Several springs 191 are provided along the circumferential direction at the end of the fixing protrusion 111. An outer preload ring 192 is provided on the end face of the fixing protrusion 111. The outer preload ring 192 is clearance-fitted with the inner wall of the housing 11, and the end face of the outer preload ring 192 is provided with an abutment portion 193. The abutment portion 193 abuts against the outer ring 181 of one of the ball bearings; that is, a ball bearing close to the outer preload ring 192.

[0047] The inner ring 182 of the ball bearing is connected to the shaft 16. The shaft 16 is provided with an inner preload ring 194. The inner preload ring 194 is in contact with the inner ring 182 of the same ball bearing, that is, a ball bearing close to the outer preload ring 192. The inner ring 182 of another ball bearing away from the outer preload ring 192 is in contact with the rear end cover 112 on the housing 11.

[0048] In the initial state, the end face of the fixed protrusion 111 and the end face of the outer preload ring 192 are in close contact.

[0049] Several springs 191 are always in a compressed state, applying a continuous axial thrust to the outer preload ring 192. This thrust is transmitted to the end face of the outer ring 181 of the ball bearing via the contact part 193 of the outer preload ring 192, so that the outer ring 181 is always subjected to an axial force in one direction. At the same time, the inner preload ring 194, which is in contact with the inner ring 182, applies a reverse axial constraint force to the inner ring 182 of the bearing. Meanwhile, the inner preload ring 194, the shaft 16, the bearing, and the rear end cover 112 are in a rigid combination state. At this time, the preload of the bearing is a positioning preload.

[0050] When the spindle is running at high speed, the temperature of the inner ring 182 of the bearing is higher than that of the outer ring. Therefore, the thermal extension of the inner preload ring 194 is longer than that of the housing 11 and the outer preload ring 192. This causes the inner ring 182 to deviate slightly from the outer ring 181, increasing the clearance between them. The compression of the spring 191 will be slightly released or further compressed accordingly, thereby adaptively adjusting the axial force applied to the outer ring 181 of the bearing. At this time, under the action of the spring 191, the outer preload ring 192 will slide to the right, pushing the outer ring 181 to fill the clearance, so that the bearing is always in a suitable preload state. It will not cause clearance due to insufficient preload, nor will it cause increased heat generation or bearing damage due to excessive preload. At this time, the preload method of the bearing will change from positioning preload to constant pressure preload.

[0051] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0052] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high-efficiency heat exchange and heat dissipation spindle structure, comprising a spindle body (1), characterized in that: The main spindle body (1) includes at least a housing (11), and the housing (11) is provided with a plurality of heat exchange pipes (2) and a cooling water channel (3) structure; The heat exchange tube (2) is used to absorb the heat at the bearing position of the housing (11) and form a cooling section in the middle of the housing (11); The cooling water circuit structure (3) is used to absorb the heat of the shell (11) and absorbs the heat of the working fluid in the heat exchange tube (2) through the part to be cooled.

2. The high-efficiency heat exchange and heat dissipation spindle structure according to claim 1, characterized in that: Along the length direction of the shell (11), a plurality of protruding ribs (12) are integrally formed on the outer periphery of the shell (11), and the protruding ribs (12) are arranged in a ring around the outer periphery of the shell (11); Each rib (12) is provided with several first grooves. The shell (11) is provided with a second groove corresponding to the first groove, and a third groove (131) extending in the same direction as the second groove. The first groove and the second groove are combined to form a limiting channel (132). The heat exchange tube (2) is inserted into the limiting channel (132), and the heat exchange tube (2) is in full contact with the inner wall of the limiting channel (132), i.e. the inner wall of the third groove (131).

3. The high-efficiency heat exchange and heat dissipation spindle structure according to claim 2, characterized in that: A dust cover (14) is fixedly provided on the rib (12).

4. The high-efficiency heat exchange and heat dissipation spindle structure according to claim 2, characterized in that: The protruding rib (12) at the front end forms a limiting channel (132) between itself and the shell (11), which serves as an entrance (151). A sealing element (152) is provided at the entrance (151).

5. The high-efficiency heat exchange and heat dissipation spindle structure according to claim 1, characterized in that: The main spindle body (1) also includes a rotating shaft (16), which is inserted into the housing (11) and connected to the front bearing assembly (17) and the rear bearing assembly (18) respectively. The housing (11) is provided with a preload assembly (19), which acts on the front bearing assembly (17) and / or the rear bearing assembly (18) to counteract the gap caused by heat generated during operation.

6. The high-efficiency heat exchange and heat dissipation spindle structure according to claim 5, characterized in that: The rear bearing assembly (18) includes at least two ball bearings stacked one after the other; The preload structure includes a cylindrical fixing protrusion (111) inside the housing (11). The end of the fixing protrusion (111) is provided with a plurality of springs (191) along its circumferential direction. An outer preload ring (192) is provided on the end face of the fixing protrusion (111). The outer preload ring (192) is clearance-fitted with the inner wall of the housing (11), and the end face of the outer preload ring (192) is provided with an abutting part (193). The abutting part (193) abuts against the outer ring (181) of one of the ball bearings. The inner ring (182) of the ball bearing is connected to the shaft (16), and the shaft (16) is provided with an inner preload ring (194). The inner preload ring (194) is in contact with the inner ring (182) of the same ball bearing, and the inner ring (182) of another ball bearing is in contact with the rear end cover (112) on the housing (11).

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