Heat dissipation device of electric spindle

Abstract

The invention provides a heat dissipation device of an electric spindle, and belongs to the technical field of heat dissipation of the electric spindle, the heat dissipation device is nested in a rotating motor of the electric spindle, the heat dissipation device comprises heat dissipation boxes and a cooling structure, the heat dissipation boxes are arranged at the two ends of the cooling structure, and the cooling structure is arranged in a shell of a stator assembly. The cooling structure is arranged to be a Z-shaped annular water jacket cooling structure, the water jacket cooling structure is connected with the heat dissipation box, during design, a simulated cooling path is designed firstly, and then the optimal cooling path and the optimal internal structure are selected according to the temperature rising characteristic. The stator casing Z-shaped annular water jacket cooling structure is adopted, the size of a water channel is optimized, heat is taken away at the maximum efficiency, the average temperature of the motor is kept below 60 DEG C, meanwhile, the cooling structure is arranged in the stator casing, and the size of the motorized spindle can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of electro-spindle heat dissipation, and particularly to a heat dissipation device for an electro-spindle. Background Art

[0002] The electro-spindle has a transmission structure mode in which the built-in motor and the machine tool spindle are "integrated into one". It can better adapt to high-speed and high-precision rotation, with small vibration, thus meeting the actual needs of precision machining and high-speed cutting of die numerical control machine tools. In actual part processing, the electro-spindle needs a tool pulling mechanism to clamp the tool for high-speed rotation, and the circular runout of the tool plays an important role in the machining accuracy of the machine tool spindle. In the industry, the circular runout of the tool reflects the quality of the overall spindle accuracy, which is ultimately reflected in the accuracy of the inspection bar. However, the high-precision runout of the overall spindle places extremely strict requirements on the spindle assembler and the tolerance grade of the part itself, and it is usually difficult to achieve the required geometric accuracy performance.

[0003] Domestic traditional conventional electro-spindles all have motors and externally driven spindles. Such products are large in size, low in efficiency, and low in speed. Abroad, induction motors are used as drives, with low power factor, low efficiency, large volume, and low power density. At the same time, air-floating bearings are used, with low impact resistance and can only be used in occasions with low torque requirements such as PCB boards. At the same time, the heat dissipation effect is not good, often resulting in high temperature, causing low efficiency. Therefore, it is necessary to design a heat dissipation device for an electro-spindle to achieve rapid heat dissipation of the electro-spindle. Summary of the Invention

[0004] The purpose of the present invention is to provide a heat dissipation device for an electro-spindle to solve the technical problems of low heat dissipation efficiency or large volume of the existing electro-spindle heat dissipation mechanism.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A heat dissipation device for an electro-spindle, the heat dissipation device is nested in the rotating motor of the electro-spindle. The heat dissipation device includes a heat dissipation box and a cooling structure. The heat dissipation box is arranged at both ends of the cooling structure. The cooling structure is arranged inside the housing of the stator assembly. The cooling structure is arranged as a Z-shaped annular water jacket cooling structure. The water jacket cooling structure is connected to the heat dissipation box. When designing, first design a simulated cooling path, and then select the optimal cooling path and internal structure according to the temperature rise characteristics.

[0007] Further, the heat dissipation box is arranged at both ends of the rotating shaft to achieve heat dissipation of the rotating shaft and control the temperature of the rotating motor and the rotating shaft below 60 degrees Celsius.

[0008] Further, the rotating motor includes a stator assembly, a rotor assembly, and a sheath. The stator assembly is arranged outside the rotor assembly. The sheath is arranged between the stator assembly and the rotor assembly. The rotating shaft is arranged inside the rotor assembly.

[0009] Further, an encoder is provided on the rotating shaft. The rotating shaft is a hollow rotating shaft, and a chuck assembly is provided at the front end of the rotating shaft.

[0010] Further, the sheath is a carbon fiber sheath, and both the front bearing and the rear bearing are magnetic levitation bearings.

[0011] Further, the electric spindle includes a housing, a front bearing mount, a front bearing, a motor assembly, a rotating shaft, a rear bearing, and a rear bearing mount. The front bearing mount and the rear bearing mount are respectively provided at both ends of the housing. The motor assembly is provided inside the housing. The front bearing is provided in the front bearing mount. The rear bearing is provided in the rear bearing mount. The rotating shaft passes through the inside of the motor assembly and is respectively provided on the front bearing and the rear bearing at both ends.

[0012] Further, an electric drive assembly is provided at the rear end of the heat dissipation device. The electric drive assembly includes a rear seat, a cylinder power member, a power ring, a mount, a push rod release mechanism, and a push rod. The power ring is provided on the cylinder power member. The push rod release mechanism is connected to the power ring and the push rod. One end of the push rod is provided on the power ring. The mount is provided at the rear end of the cylinder power member. The rear seat is provided on the heat dissipation assembly. The push rod release mechanism is provided on the rear seat. The push rod passes through the rear seat and is provided inside the rotating shaft.

[0013] Further, when designing the heat dissipation device, first, heat source analysis is carried out. The heat sources include Joule heat generated when current passes through the winding, friction between the internal grease or oil film and the rolling elements during bearing rotation, and energy loss of transmission components converted into heat. A mathematical model based on finite element analysis is established and analyzed in combination with structural mechanics and fluid mechanics. Then, parameter estimation is set, including the heat generated per unit time, physical quantities of material thermal conductivity, geometric dimensions of heat dissipation efficiency, and ambient air temperature and humidity. When dissipating heat, data of the external environment and the characteristics of the internal self - used materials and relevant data of rotation are collected through the control board, and then the speed of liquid cooling is controlled.

[0014] Due to the adoption of the above - mentioned technical solutions, the present invention has the following beneficial effects:

[0015] The present invention adopts a Z - shaped annular water jacket cooling structure for the stator housing, optimizes the size of the water channel, takes away heat with the maximum efficiency, keeps the average temperature of the motor below 60 degrees Celsius, and at the same time, by arranging the cooling structure inside the stator housing, the volume of the electric spindle can be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of the heat dissipation device of the electric spindle of the present invention;

[0017] Figure 2 is a schematic structural diagram of the electric spindle of the present invention;

[0018] Figure 3 is a schematic diagram of the air circuit structure of the electric spindle of the present invention;

[0019] Figure 4 is a comparison chart of the rotational speed and torque of the present invention and the rotational speed and torque data of the existing electric spindle;

[0020] Figure 5 is a simulated heat dissipation effect diagram of the heat dissipation device of the electric spindle of the present invention;

[0021] In the drawings, 1 - housing, 2 - front bearing mounting seat, 3 - front bearing, 4 - chuck assembly, 5 - rotating shaft, 6 - sheath, 7 - stator assembly, 8 - rotor assembly, 9 - heat dissipation box, 10 - encoder, 11 - rear bearing, 12 - rear bearing mounting seat, 13 - rear seat, 14 - cylinder power component, 15 - power ring, 16 - mounting seat, 17 - push rod release mechanism, 18 - push rod. Detailed implementation manners

[0022] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following presents preferred embodiments with reference to the accompanying drawings and further elaborates on the present invention in detail. However, it should be noted that many details listed in the specification are only for enabling the reader to have a thorough understanding of one or more aspects of the present invention, and these aspects of the present invention can be implemented even without these specific details.

[0023] As Figure 1 shown, a heat dissipation device of an electric spindle, the heat dissipation device is nested in the rotating motor of the electric spindle, the heat dissipation device includes a heat dissipation box 9 and a cooling structure, the heat dissipation box 9 is arranged at both ends of the cooling structure, the cooling structure is arranged inside the housing of the stator assembly 7, the cooling structure is arranged as a Z-shaped annular water jacket cooling structure, the water jacket cooling structure is connected to the heat dissipation box 9. During design, first design the simulated cooling path, and then select the optimal cooling path and internal structure according to the heating characteristics. The heat dissipation box 9 is arranged at both ends of the rotating shaft 5 to achieve heat dissipation of the rotating shaft 5 and control the temperature of the rotating motor and the rotating shaft 5 below 60 degrees Celsius.

[0024] In an embodiment of the present invention, as Figure 2 shown, the rotating motor includes a stator assembly 7, a rotor assembly 8 and a sheath 6, the stator assembly 7 is arranged outside the rotor assembly 8, the sheath 6 is arranged between the stator assembly 7 and the rotor assembly 8, and the rotating shaft 5 is arranged inside the rotor assembly 8. An encoder 10 is arranged on the rotating shaft 5, the rotating shaft 5 is a hollow rotating shaft, and a chuck assembly 4 is arranged at the front end of the rotating shaft 5. The sheath 6 is a carbon fiber sheath, and both the front bearing 3 and the rear bearing 11 are magnetic levitation bearings.

[0025] In an embodiment of the present invention, the motorized spindle includes a housing 1, a front bearing mounting seat 2, a front bearing 3, a motor assembly, a rotating shaft 5, a rear bearing 11, and a rear bearing mounting seat 12. The front bearing mounting seat 2 and the rear bearing mounting seat 12 are respectively arranged at both ends of the housing 1. The motor assembly is arranged inside the housing 1. The front bearing 3 is arranged inside the front bearing mounting seat 2. The rear bearing 11 is arranged inside the rear bearing mounting seat 12. The rotating shaft 5 passes through the inside of the motor assembly, and both ends are respectively arranged on the front bearing 3 and the rear bearing 11.

[0026] In an embodiment of the present invention, as Figure 3 shown, an electric drive assembly is arranged at the rear end of the heat dissipation device. The electric drive assembly includes a rear seat 13, a cylinder power member 14, a power ring 15, a mounting seat 16, a push rod release mechanism 17, and a push rod 18. The power ring 15 is arranged on the cylinder power member 14. The push rod release mechanism 17 is connected to the power ring 15 and the push rod 18. One end of the push rod 18 is arranged on the power ring 15. The mounting seat 16 is arranged at the rear end of the cylinder power member 14. The rear seat 13 is arranged on the heat dissipation assembly. The push rod release mechanism 17 is arranged on the rear seat 13. The push rod 18 passes through the rear seat 13 and is arranged inside the rotating shaft 5.

[0027] In the design of the heat dissipation device in an embodiment of the present invention, first, a heat source analysis is carried out. The heat sources include Joule heat generated when current passes through the winding, friction between the internal grease or oil film and the rolling elements during bearing rotation, and energy loss of transmission components converted into heat. A mathematical model based on finite element analysis is established and analyzed in combination with structural mechanics and fluid mechanics. Then, parameter estimation is set, including the heat generated per unit time, physical quantities of material thermal conductivity, geometric dimensions of heat dissipation efficiency, and ambient air temperature and humidity. When dissipating heat, data of the external environment and the characteristics of the internal self - used materials and relevant data of rotation are collected through a control board, and then the speed of liquid cooling is controlled.

[0028] When designing the motorized spindle, several physical field co - simulation designs are adopted, including electromagnetic design, heat dissipation design, and mechanical mechanics simulation design. At the same time, the methods of harmonic pole - cutting and harmonic injection are used to improve the torque density of the permanent magnet motor system. The coupling relationship between the motor and the controller is fully considered, so as to achieve high - speed precision dynamic control and improve the overall efficiency of the motor system. Through refined analysis of iron loss and optimization of dimensions, the efficiency of the motorized spindle is improved to create a high - efficiency and energy - saving motorized spindle brand.

[0029] As Figure 4 shown, Figure 4 The second figure is the result data of this application. Figure 4 The first figure is the data of the existing Xifeng brand motorized spindle. The torque of this application is much larger than that of the existing motorized spindle, and at the same time, the rotational speed is also higher, achieving a step - by - step breakthrough.

[0030] The rated voltage (Vdc) of this motorized spindle is 208, the continuous power (kW) is 2.0, the maximum dynamic runout (μm) is 7 (at 150,000 rpm), the continuous torque (Nm) is 0.1273, the continuous load (Nm) is 2,000, the rated speed (rpm) is 150,000, the maximum speed (rpm) is 160,000, the operating temperature range (°C) is -40 to +65, the locked-rotor torque (Nm) is 7.47, the maximum chuck torque (Nm) is 2.3, the maximum leakage current (mA) is 0.01, the reference mass (kg) is 2.5, and the reference dimensions (mm) are Φ50×200.

[0031] As Figure 5 shown, the heat dissipation mechanism of this application can reduce the overall average temperature to 60 degrees Celsius, achieving good temperature reduction and improving the accuracy of the motorized spindle.

[0032] Matters not covered by this invention are well-known technologies.

[0033] The above are only the preferred embodiments of this invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of this invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of this invention.

Claims

1. A heat dissipation device for an electric spindle, characterized in that: The heat dissipation device is nested inside the rotating motor of the electric spindle. The heat dissipation device includes a heat dissipation box (9) and a cooling structure. The heat dissipation box (9) is arranged at both ends of the cooling structure. The cooling structure is arranged inside the housing of the stator assembly (7). The cooling structure is arranged as a Z-shaped annular water jacket cooling structure. The water jacket cooling structure is connected to the heat dissipation box (9). During the design, the simulated cooling path is designed first, and then the optimal cooling path and internal structure are selected according to the temperature rise characteristics.

2. The heat dissipation device of an electric spindle according to claim 1, characterized in that: The heat dissipation box (9) is arranged at both ends of the rotating shaft (5) to dissipate heat from the rotating shaft (5) and control the temperatures of the rotating motor and the rotating shaft (5) below 60 degrees Celsius.

3. The heat dissipation device of an electric spindle according to claim 1, characterized in that: The rotating motor includes a stator assembly (7), a rotor assembly (8), and a sheath (6). The stator assembly (7) is arranged outside the rotor assembly (8). The sheath (6) is arranged between the stator assembly (7) and the rotor assembly (8). The rotating shaft (5) is arranged inside the rotor assembly (8).

4. The heat dissipation device for an electric spindle according to claim 3, characterized in that: An encoder (10) is arranged on the rotating shaft (5). The rotating shaft (5) is a hollow rotating shaft, and a chuck assembly (4) is arranged at the front end of the rotating shaft (5).

5. The heat dissipation device of an electric spindle according to claim 3, characterized in that: The sheath (6) is a carbon fiber sheath, and both the front bearing (3) and the rear bearing (11) are magnetic levitation bearings.

6. The heat dissipation device for an electric spindle according to claim 1, characterized in that: The electric spindle includes a housing (1), a front bearing mount (2), a front bearing (3), a motor assembly, a rotating shaft (5), a rear bearing (11), and a rear bearing mount (12). The front bearing mount (2) and the rear bearing mount (12) are respectively arranged at both ends of the housing (1). The motor assembly is arranged inside the housing (1). The front bearing (3) is arranged inside the front bearing mount (2). The rear bearing (11) is arranged inside the rear bearing mount (12). The rotating shaft (5) passes through the inside of the motor assembly and is respectively arranged on the front bearing (3) and the rear bearing (11) at both ends.

7. The heat dissipation device for an electric spindle according to claim 3, characterized in that: An electric drive assembly is arranged at the rear end of the heat dissipation device. The electric drive assembly includes a rear seat (13), a cylinder power component (14), a power ring (15), a mount (16), a push rod release mechanism (17), and a push rod (18). The power ring (15) is arranged on the cylinder power component (14). The push rod release mechanism (17) is connected to the power ring (15) and the push rod (18). One end of the push rod (18) is arranged on the power ring (15). The mount (16) is arranged at the rear end of the cylinder power component (14). The rear seat (13) is arranged on the heat dissipation assembly. The push rod release mechanism (17) is arranged on the rear seat (13). The push rod (18) passes through the rear seat (13) and is arranged inside the rotating shaft (5).

8. The heat dissipation device for an electric spindle according to claim 1, characterized in that: When designing a heat dissipation device, first conduct a heat source analysis. The heat sources include Joule heat generated when current passes through the winding, friction between the internal grease or oil film and the rolling elements during bearing rotation, and energy loss of transmission components converted into heat. Establish a mathematical model based on finite element analysis and perform analysis by combining structural mechanics and fluid mechanics. Then, set parameter estimations, including the heat generated per unit time, physical quantities of material thermal conductivity, geometric dimensions of heat dissipation efficiency, and ambient air temperature and humidity. When dissipating heat, collect data on the external environment, material characteristics of the internal components, and relevant data on rotation through a control board, and then control the speed of liquid cooling.

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