Motorized spindle cooling water jacket with turbulent flow structure

Abstract

The invention is suitable for the technical field of electric spindles of numerical control machine tools, and provides an electric spindle cooling water jacket with a turbulent flow structure, a spiral flow channel is formed in the cooling water jacket, and the spiral flow channel is composed of a water inlet flow channel and a water outlet flow channel which are continuously and alternately arranged; a first turbulent flow structure and a second turbulent flow structure are arranged in the water inlet flow channel and the water outlet flow channel respectively, the first turbulent flow structure and the second turbulent flow structure are each composed of a turbulent flow column and a turbulent flow rib, and the turbulent flow columns are located in the middle of the rear portions of the turbulent flow ribs on the two sides. Under the condition that the flow and the temperature of cooling liquid are not changed, the heat exchange efficiency is improved by optimizing the turbulent flow structure, and energy consumption is prevented from being increased. Through the design of the spiral flow channel and the turbulent flow structure, heat exchange of a high-temperature area is enhanced, the highest temperature of the cooling water jacket and the temperature of a corresponding area are effectively reduced, and compared with a double-spiral cooling water jacket, the comprehensive heat exchange index of the cooling water jacket is improved. And meanwhile, the overall structure of the cooling water jacket is slightly changed, so that the manufacturing cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of electric spindles for numerically controlled machine tools, and in particular relates to an electric spindle cooling water jacket with a turbulent structure. Background Art

[0002] In modern manufacturing, machine tools are the core equipment for precision machining, and their performance and efficiency are directly related to the quality and market competitiveness of industrial products. Among them, high-speed and high-precision electric spindle units are the core functional components of high-end CNC machine tools. Compared with traditional mechanical spindles, electric spindles have the characteristics of "zero transmission", that is, the intermediate transmission device is omitted, the integration of the machine tool spindle and the drive motor is realized, and the spindle unit is directly driven by the motor. In addition, the electric spindle has the advantages of compact structure, light weight, fast dynamic response and high rotation accuracy. However, during the operation of the electric spindle, the heat source inside the spindle will cause temperature rise, which will cause thermal deformation of the spindle, which will not only reduce the machining accuracy, but also shorten the service life of the electric spindle. According to research, among the various errors that affect the machining accuracy of CNC machine tools, thermal errors account for 40%-70%. Therefore, the thermal performance of the spindle system is crucial to the service life and machining accuracy of CNC machine tools, and it is of great significance to improve the cooling effect of the electric spindle cooling unit.

[0003] At present, the electric spindle mainly dissipates heat by injecting low-temperature coolant into the cooling water jacket. The coolant removes the heat generated inside the electric spindle by convection heat transfer. Although the heat transfer efficiency can be changed by adjusting the coolant-related parameters (such as coolant flow and temperature) and the cooling water jacket structure (such as cooling water jacket type and structural parameters), there are still the following shortcomings:

[0004] (1) Coolant-related parameters: Most of the heat generated by the internal heat source of the electric spindle is transferred to the outside through the convection heat transfer of the coolant. Increasing the coolant flow rate and reducing the coolant inlet temperature can increase the coolant convection heat transfer coefficient, strengthen heat transfer, and thus improve the heat transfer efficiency of the cooling water jacket. However, increasing the coolant flow rate and reducing the temperature have limited effects on the improvement of heat transfer efficiency and will lead to an increase in the energy consumption of the cooling unit.

[0005] (2) Cooling water jacket structure: Cooling water jackets with different structures have different cooling effects. Adjusting the size parameters and cross-sectional shape of the flow channel also has different effects on the cooling effect. However, when adjusting the above factors, there is often a lack of targeted consideration of cooling in high-temperature areas. In addition, some improvement plans require major changes to the cooling water jacket structure, which will increase the manufacturing cost of the cooling water jacket.

[0006] In view of the above problems, the present invention proposes an electric spindle cooling water jacket with a turbulent structure. Summary of the invention

[0007] The purpose of the present invention is to provide an electric spindle cooling water jacket with a turbulent structure, aiming to solve the problems raised in the above background technology.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A motorized spindle cooling water jacket with a spoiler structure, wherein the cooling water jacket is fixed on the motorized spindle, the outer shell of the motorized spindle and the cooling water jacket are closely matched together, a water inlet and a water outlet are provided on the cooling water jacket, a spiral flow channel is provided on the cooling water jacket, the spiral flow channel is composed of a water inlet flow channel and a water outlet flow channel that are continuously and alternately arranged, a spoiler structure 1 and a spoiler structure 2 are respectively arranged in the water inlet flow channel and the water outlet flow channel, the spoiler structure 1 and the spoiler structure 2 are both composed of a spoiler column and a spoiler rib, and the spoiler column is located in the rear middle of the spoiler ribs on both sides;

[0010] In the spoiler structure 1, the spoiler column is a water inlet flow channel spoiler column, and the spoiler ribs on both sides are water inlet flow channel spoiler rib 1 and water inlet flow channel spoiler rib 2. The angle formed by the water inlet flow channel spoiler column and the water inlet flow channel spoiler rib 1 and water inlet flow channel spoiler rib 2 on both sides is directly opposite to the flow direction of the coolant;

[0011] In the second spoiler structure, the spoiler column is a water outlet channel spoiler column, and the spoiler ribs on both sides are water outlet channel spoiler rib 1 and water outlet channel spoiler rib 2. The angle formed by the water outlet channel spoiler column and the water outlet channel spoiler rib 1 and the water inlet channel spoiler rib 2 on both sides is directly opposite to the flow direction of the coolant.

[0012] Furthermore, the structure of the spoiler column is a column with a straight-sided ellipse as its cross section.

[0013] Furthermore, the angle φ of the spoiler column is 10°.

[0014] Furthermore, the type of the spoiler ribs is discontinuous oblique ribs.

[0015] Furthermore, the width b of the spoiler rib is 2 mm.

[0016] Furthermore, an upper width w1 between the spoiler ribs on both sides is 8 mm, and a lower width w2 between the spoiler ribs on both sides is 10 mm.

[0017] Furthermore, the spoiler columns and spoiler ribs are evenly distributed in the water inlet channel and the water outlet channel.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention achieves an improvement in heat exchange efficiency by optimizing the spoiler structure without changing the coolant flow rate and temperature, thereby avoiding an increase in energy consumption. Specifically, the present invention, through the ingenious design of the spiral flow channel and the spoiler structure, strengthens the heat exchange treatment especially for the high-temperature area, which not only effectively reduces the maximum temperature of the cooling water jacket and the temperature of the corresponding area, but also improves the comprehensive heat exchange index of the present invention compared with the double-helix cooling water jacket. At the same time, the present invention has relatively small changes to the overall structure of the cooling water jacket, reducing the manufacturing cost. The present invention is of great significance for improving the performance and service life of the electric spindle, especially in the field of high-end CNC machine tools such as swing angle milling heads. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of a separate cooling water jacket flow channel.

[0021] Figure 2 Schematic diagram of the three-dimensional structure of the spoiler structure flow channel.

[0022] Figure 3 Dimensional drawing of the spoiler structure.

[0023] Figure 4 The sensitivity analysis results of the spoiler structure size.

[0024] Figure 5 This is the result of improving the spoiler structure size.

[0025] Figure 6 It is the coolant flow state in the vertical plane of the flow channel.

[0026] Figure 7 It is the flow state of coolant in the horizontal plane of the flow channel.

[0027] Figure 8 It is the coolant flow state in the flow channel cross section.

[0028] Fig. 9 It is the distribution cloud diagram of heat transfer coefficient in the flow channel.

[0029] Fig.10 It is a schematic diagram of the three-dimensional structure of the cooling water jacket.

[0030] Fig.11 This is the front view of the cooling water jacket.

[0031] Fig.12 It is a schematic diagram of the three-dimensional structure of the electric spindle.

[0032] Fig.13 Schematic diagram of the three-dimensional structure of the electric spindle after the outer shell is removed and the cooling water jacket is installed.

[0033] In the figure: cooling water jacket flow channel 1, spoiler structure flow channel 2, cooling water jacket 3, water inlet flow channel spoiler column 4, water inlet flow channel spoiler rib 1 5, water inlet flow channel spoiler rib 2 6, water outlet flow channel spoiler column 7, water outlet flow channel spoiler rib 1 8, water outlet flow channel spoiler rib 2 9, water inlet 10, water outlet 11, electric spindle 12, housing 13. DETAILED DESCRIPTION

[0034] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0035] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0036] The embodiment of the present invention provides a spindle cooling water jacket with a turbulent structure. In order to improve the heat exchange efficiency of the cooling water jacket 3 to the high temperature area and improve the thermal characteristics of the spindle 12 at a low cost, a single cooling water jacket flow channel 1 is used as the design object ( Figure 1 ), a flow disturbance structure, namely, a flow disturbance structure flow channel 2 ( Figure 2 ), the spoiler structure in the spoiler structure flow channel 2 includes spoiler ribs and spoiler columns. The spoiler ribs are intermittent oblique ribs, and the oblique ribs are opposite to the flow direction of the coolant. The spoiler column is a column with a straight-edged ellipse as the cross-section. The spoiler column is located in the middle of the rear of the spoiler ribs on both sides. The spoiler ribs and spoiler columns are evenly distributed in the flow channel. The size diagram of the spoiler structure is shown in FIG. Figure 3 As shown in Figure 1, it includes the spoiler rib width b, the spoiler rib upper width w1, the spoiler rib lower width w2 and the spoiler column angle φ. The sensitivity analysis of the spoiler structure size is carried out, and the sensitivity of each size to the flow channel pressure drop, temperature and fluid Nusselt number is shown in Figure 1. Figure 4 As shown in the figure, except for the spoiler rib width b, the other dimensions have a great influence on the flow channel parameters. When the spoiler rib width w1 and the spoiler rib width w2 increase, the flow channel pressure drop and the fluid Nusselt number decrease, and the flow channel temperature increases; when the spoiler column angle φ increases, the flow channel pressure drop and the fluid Nusselt number increase, and the flow channel temperature decreases. According to the above analysis results, the spoiler structure dimensions are improved, and the improvement results are shown in Figure 5 As shown, the width b of the spoiler rib is 2 mm, the upper width w1 between the spoiler ribs on both sides is 8 mm, the lower width w2 between the spoiler ribs on both sides is 10 mm, and the angle φ of the spoiler column is 10°.

[0037] Figure 6The flow state of the coolant in the vertical plane of the flow channel is shown. Under the influence of the spoiler column, the coolant above the spoiler column has a higher flow rate. When the coolant on both sides of the spoiler column flows to the rear of the spoiler column, it will flow toward the middle vertical plane and produce an impact when it meets, thereby generating two flows with opposite directions in the vertical plane. The fluid flowing downward further forms a more obvious vortex in the vertical plane when it flows to the bottom of the flow channel.

[0038] Figure 7 The flow state of the coolant in the horizontal plane of the flow channel is shown. Under the influence of the spoiler ribs, the coolant flow velocity in the middle area of ​​the flow channel is relatively high, and a more obvious vortex is formed behind the spoiler ribs. Under the influence of the spoiler column, the coolant flow velocity on both sides of the spoiler column is relatively high, and affected by the vortex in the vertical plane and the fluid on both sides of the spoiler column in the horizontal plane, two vortices with opposite rotation directions are formed in the horizontal plane behind the spoiler column.

[0039] Figure 8 The flow state of the coolant in the cross section of the flow channel is displayed. Under the influence of the vortices on both sides of the flow channel, the flow velocity on both sides of the cross section is lower, the coolant flow velocity in the middle area is larger, and the coolant at the bottom of the middle area is affected by the vortex behind the spoiler, and vortices with opposite rotation directions are also generated in the cross section. The vortex area is roughly a triangular area.

[0040] Fig. 9 The heat transfer coefficient distribution cloud diagram in the flow channel is shown. The coolant in the middle area of ​​the flow channel has a higher flow velocity under the influence of the turbulent structure, and the destruction of the boundary layer caused by the fluid disturbance and the enhancement of fluid mixing improve the heat transfer capacity of the flow channel. The heat transfer coefficient in the middle part is relatively large, and the heat transfer coefficient of the part in contact with the bottom surface of the flow channel is the largest. The area behind the turbulent rib has a lower flow velocity due to the influence of vortex, and the heat transfer coefficient is lower than that of other areas, but overall the heat transfer capacity of the flow channel is improved.

[0041] like Figure 10-13 As shown, as a preferred embodiment of the present invention, the cooling water jacket 3 is fixed on the electric spindle 12, and the outer shell 13 of the electric spindle 12 is tightly matched with the cooling water jacket 3. The cooling water jacket 3 is provided with a water inlet 10 and a water outlet 11, and the cooling water jacket 3 is provided with a spiral flow channel; the spiral flow channel is composed of a continuously alternately arranged water inlet flow channel and a water outlet flow channel, and the water inlet flow channel and the water outlet flow channel are respectively provided with a first spoiler structure and a second spoiler structure, and these spoiler structures are composed of spoiler columns and spoiler ribs, and the angles formed are all directly opposite to the flow direction of the coolant.

[0042] Specifically, a spoiler structure 1 composed of a water inlet channel spoiler column 4, a water inlet channel spoiler rib 1 5 and a water inlet channel spoiler rib 2 6 is arranged in the water inlet channel, and the angle formed between the water inlet channel spoiler column 4 and the water inlet channel spoiler rib 1 5 and the water inlet channel spoiler rib 2 6 on both sides is directly opposite to the flow direction of the coolant; a spoiler structure 2 composed of a water outlet channel spoiler column 7, a water outlet channel spoiler rib 1 8 and a water outlet channel spoiler rib 2 9 is arranged in the water outlet channel, and the angle formed between the water outlet channel spoiler column 7 and the water outlet channel spoiler rib 1 8 and the water outlet channel spoiler rib 2 9 on both sides is directly opposite to the flow direction of the coolant.

[0043] In the embodiment of the present invention, the working principle is as follows: the coolant flows into the cooling water jacket 3 from the water inlet 10, and after being disturbed by the spiral flow channel and the flow disturbance structure, flows out from the water outlet 11. This flow path ensures that the coolant can fully contact the inner wall of the cooling water jacket 3 and take away the heat generated inside the electric spindle 12.

[0044] The arrangement of the turbulent structure not only increases the heat exchange area of ​​the cooling water jacket 3 and enhances the heat exchange efficiency, but also enhances the mixing of the coolant and the destruction of the coolant boundary layer by disturbing the flow state of the coolant, thereby further enhancing the convective heat exchange in the corresponding area.

[0045] The above are only preferred embodiments of the present invention. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These should also be regarded as the protection scope of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A cooling water jacket for an electric spindle with a turbulent structure, wherein the cooling water jacket is fixed on the electric spindle, the outer shell of the electric spindle and the cooling water jacket are tightly matched together, and a water inlet and a water outlet are provided on the cooling water jacket, characterized in that: The cooling water jacket is provided with a spiral flow channel, the spiral flow channel is composed of an inlet flow channel and an outlet flow channel that are continuously and alternately arranged, a first spoiler structure and a second spoiler structure are respectively arranged in the inlet flow channel and the outlet flow channel, the first spoiler structure and the second spoiler structure are both composed of a spoiler column and a spoiler rib, and the spoiler column is located in the middle of the rear of the spoiler ribs on both sides; In the spoiler structure 1, the spoiler column is a water inlet flow channel spoiler column, and the spoiler ribs on both sides are water inlet flow channel spoiler rib 1 and water inlet flow channel spoiler rib 2. The angle formed by the water inlet flow channel spoiler column and the water inlet flow channel spoiler rib 1 and water inlet flow channel spoiler rib 2 on both sides is directly opposite to the flow direction of the coolant; In the second spoiler structure, the spoiler column is a water outlet channel spoiler column, and the spoiler ribs on both sides are water outlet channel spoiler rib 1 and water outlet channel spoiler rib 2. The angle formed by the water outlet channel spoiler column and the water outlet channel spoiler rib 1 and the water inlet channel spoiler rib 2 on both sides is directly opposite to the flow direction of the coolant.

2. The electric spindle cooling water jacket with a turbulent structure according to claim 1, characterized in that: The structure of the spoiler column is a column with a straight-sided ellipse as the cross section.

3. The electric spindle cooling water jacket with a turbulent structure according to claim 1, characterized in that: The angle φ of the spoiler column is 10°.

4. The electric spindle cooling water jacket with a turbulent structure according to claim 1, characterized in that: The type of the spoiler rib is discontinuous oblique rib.

5. The electric spindle cooling water jacket with a turbulent structure according to claim 1, characterized in that: The width b of the spoiler rib is 2 mm.

6. The electric spindle cooling water jacket with a turbulent structure according to claim 1, characterized in that: The upper width w1 between the spoiler ribs on both sides is 8 mm, and the lower width w2 between the spoiler ribs on both sides is 10 mm.

7. The electric spindle cooling water jacket with a turbulent structure according to claim 1, characterized in that: The spoiler columns and spoiler ribs are evenly distributed in the water inlet flow channel and the water outlet flow channel.

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