A motor bearing temperature equalization device based on heat pipe temperature equalization technology

Abstract

This invention discloses a motor bearing temperature equalization device based on heat pipe equalization technology, comprising a stator and a rotor. The stator has a motor mounting base, which includes a circular tube section, a transition section, and a disc section. The circular tube section and the transition section each have at least one hollow bearing seat for mounting bearings. At least one mounting groove is provided on the outer side of the circular tube section and the transition section, and a heat pipe is embedded and fixed within the mounting groove. The heat pipe is filled with a working fluid and includes a capillary structure to achieve working fluid circulation. This invention connects the bearing seats on both sides of the motor via heat pipes, utilizing the phase change heat transfer principle and the extremely high thermal conductivity of the heat pipes for efficient long-distance heat transfer to achieve active temperature difference control, thereby reducing thermal stress and extending bearing life. Since bearing life is a bottleneck for the lifespan of motors and even products in some applications, overcoming this bottleneck can effectively improve the overall lifespan.

Description

Technical Field

[0001] This utility model relates to the field of motor design and thermal management technology, and in particular to a motor bearing temperature equalization device based on heat pipe temperature equalization technology. Background Technology

[0002] During motor operation, uneven load, different heat dissipation conditions, assembly errors, or poor lubrication often lead to significant temperature differences (ΔT>15℃) between the bearings on both sides of the motor. Long-term uneven temperature differences can cause thermal stress deformation, accelerated grease deterioration, and ultimately reduce bearing life or even cause failure.

[0003] To address the above issues, traditional solutions typically employ the following three measures: 1. Forced cooling: This involves adding fans or liquid cooling systems to lower the temperature on the high-temperature side. However, this increases energy consumption and complicates the structural design, and the operation of the cooling fans can cause vibration and increase noise. 2. Lubrication optimization: This involves adjusting the grease distribution or replacing it with a higher viscosity lubricant, but this method has limited effectiveness in regulating temperature differences. 3. Mechanical calibration: This involves readjusting the rotor's dynamic balance or bearing preload, but this method cannot respond to dynamic temperature changes in real time.

[0004] Existing methods struggle to achieve sustained and rapid temperature equilibrium in bearings with low energy consumption and without additional moving parts, and require significant modifications to the original motor structure. Furthermore, the addition of a cooling fan may introduce vibration and noise.

[0005] Heat pipes, as a new type of cooling element with advantages such as extremely high thermal conductivity, long-distance heat transfer, and good isothermal properties, are widely used in electronic equipment, aerospace, energy systems, and other fields. They transfer heat through the evaporation and condensation of liquid within a fully enclosed vacuum tube. Utilizing fluid principles such as capillary action, they achieve excellent cooling effects and operate independently based solely on physical principles, requiring no additional energy. Utility Model Content

[0006] To avoid the limitations of air cooling (limited cooling effect, high noise, short fan life) and liquid cooling (large size, inconvenient installation and maintenance, prone to leakage, low safety, and relatively high price), this invention designs a motor bearing temperature equalization device based on heat pipe temperature equalization technology. By connecting the bearing seats on both sides of the motor through heat pipes, and utilizing the phase change heat transfer principle and the extremely high thermal conductivity of the heat pipes for efficient long-distance heat transfer, active temperature difference regulation is achieved, thereby reducing thermal stress and extending bearing life. Since bearing life is a bottleneck for the lifespan of motors and even the entire product in some applications, overcoming this bottleneck can effectively improve the overall lifespan.

[0007] The present invention adopts the following technical solution:

[0008] A motor bearing temperature equalization device based on heat pipe temperature equalization technology includes a stator and a rotor. The stator has a motor connection seat, which includes a circular tube section, a transition section, and a disc section. The circular tube section and the transition section have at least one hollow bearing seat for mounting the bearing. At least one mounting groove is provided on the outer side of the circular tube section and the transition section. A heat pipe is embedded and fixed in the mounting groove. The heat pipe is filled with a working fluid and includes a capillary structure to achieve working fluid circulation.

[0009] Preferably, the connecting seat has a first bearing seat inside the circular tube section and a second bearing seat inside the transition section.

[0010] Preferably, the heat pipe is connected to the bearing housing through a thermally conductive interface layer.

[0011] Preferably, the thermal interface layer is a sintered metal pad or thermal grease with a thickness of ≤0.5mm.

[0012] Preferably, the heat pipe includes an evaporation section, an insulation section, and a condensation section, with the evaporation section being thermally connected to the first bearing housing and the condensation section being thermally connected to the second bearing housing.

[0013] Preferably, the heat pipe is a copper-water working fluid gravity-assisted heat pipe with an operating temperature range of 40~120℃.

[0014] Preferably, the depth of the mounting channel is 1~5mm, which matches the shape of the heat pipe.

[0015] Preferably, the heat pipe is axially fixed to the end face of the mounting channel, the evaporation section is radially in contact with the stator, and the condensation section is radially fixed by screws.

[0016] Preferably, the number of heat pipes is determined by the motor load and operating conditions. For motors operating under high load and high temperature, multiple heat pipes can be arranged in parallel around the circumference.

[0017] The working principle of this invention is as follows: The heat generated by the motor's operation rises rapidly due to poor heat dissipation in the first bearing housing area. This heat is transferred to the evaporation end of the heat pipe in contact with the bearing housing. The liquid in the capillary evaporates quickly, and the vapor flows to the condensation section under a small pressure difference, releasing heat. The condensation section transfers the heat to the second bearing housing and the outside of the motor through heat conduction. The motor's operation drives the fan to carry away the heat. The vapor, after releasing heat, condenses into liquid and flows back to the evaporation section through capillary force (if the fan is horizontally installed) or gravity (if the fan is vertically installed), completing the cycle. This continuously balances the bearing temperature within the first and second bearing housings, enhancing heat conduction between the bearings in the first and second bearing housings.

[0018] The beneficial effects of this utility model are: (1) Compared with the prior art, the motor bearing temperature equalization and enhanced heat dissipation device based on heat pipe temperature equalization technology proposed in this utility model has a good heat dissipation effect and excellent thermal response based on the heat pipe, which effectively improves the heat conduction effect without additional power consumption; (2) The temperature equalization device used in this utility model is a heat dissipation element embedded in a stationary component, which does not generate additional noise; (3) The heat pipe of the temperature equalization device used in this utility model can be matched with the working medium according to the motor operating temperature range (such as water-based working medium for 40~120℃ conditions and liquid metal for high temperature scenarios), which has good adaptability; (4) The heat pipe of the heat dissipation device of this utility model is embedded and does not occupy external space; (5) The motor implementing this utility model can effectively improve the operating power and bearing life. Attached Figure Description

[0019] Figure 1 This utility model relates to a cross-sectional view of an electric motor structure;

[0020] Figure 2 This utility model relates to a partial view of a motor connector with an embedded heat pipe.

[0021] Figure 3 This is a diagram showing the internal capillary structure and working fluid circulation path of a heat pipe;

[0022] Figure 4 This is a schematic diagram of the traditional heat dissipation method for external rotor motors;

[0023] Figure 5 This is a heat dissipation path diagram of the external rotor motor of this utility model;

[0024] In the diagram: 1-Stator, 2-Rotor, 11-Motor connector, 111-Circular tube section, 112-Transition section, 113-Disc section, 1111-Mounting channel, 1112-First bearing housing, 1113-Second bearing housing, 3-Heat pipe, 31-Evaporation section, 32-Condensation section, 4-Heat-conducting interface layer, 5-Screw. Detailed Implementation

[0025] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0026] Example: Figure 1 and Figure 2As shown, a motor bearing temperature equalization device based on heat pipe temperature equalization technology includes a stator 1 and a rotor 2. The stator has a motor connecting seat 3, which includes a circular tube section 111, a transition section 112, and a disc section 113. The circular tube section and the transition section have two hollow bearing seats inside for mounting bearings. The circular tube section of the connecting seat has a first bearing seat 1112 inside, and the transition section has a second bearing seat 1113 inside. A mounting groove 1111 is provided on the outside of the circular tube section and the transition section. A heat pipe 3 is embedded and fixed in the mounting groove. The heat pipe is filled with a working fluid and includes a capillary structure to achieve working fluid circulation.

[0027] The heat pipe is connected to the bearing housing via a thermally conductive interface 4. The thermally conductive interface layer is a sintered metal gasket or thermally conductive silicone grease with a thickness ≤0.5mm. The heat pipe includes an evaporation section 31, an adiabatic section, and a condensation section 32. The evaporation section is thermally connected to the first bearing housing, and the condensation section is thermally connected to the second bearing housing. The heat pipe is a copper-water gravity-assisted heat pipe with an operating temperature range of 40~120℃.

[0028] like Figure 1 and Figure 2 As shown, an I-shaped channel with a depth of 2mm, a width of 7mm, and a length of 96mm is machined on the outer side of the motor connector tube to the disk. A flat heat pipe is embedded in the channel, and the shape of the heat pipe matches the I-shaped channel (96mm in length, 7mm in width, and 2mm in thickness).

[0029] The heat pipe is bonded to the bearing housing metal substrate using vacuum brazing, achieving a contact thermal resistance of <0.01K / W. Both the condenser and evaporator end faces of the heat pipe contact the machined grooves in the motor housing, achieving axial positioning of the heat pipe. Five screws are added to the right end face of the mounting groove to achieve radial positioning of the heat pipe's condenser section. The heat pipe's working principle is as follows: Figure 3 As shown.

[0030] Figure 4 This is a schematic diagram of a traditional heat dissipation method for an external rotor motor. Figure 5 This is a schematic diagram of the heat dissipation method for an external rotor motor according to the present invention. While maintaining the traditional heat dissipation path of an external rotor motor, the present invention adds heat pipes to achieve temperature equalization and enhance heat dissipation, thereby improving the heat conduction path. Due to the extremely high thermal conductivity of the heat pipes, temperature equalization and enhanced heat dissipation of the motor bearing system are achieved. Specifically, the thermal conductivity of the cast aluminum parts ranges from 250 W / m*K to 1500 W / m*K, and the effective thermal conductivity of the heat pipes ranges from 5000 W / m*K to 200000 W / m*K.

[0031] In some embodiments, the heat pipe extends into the disk segment, thereby enhancing heat dissipation in both the heat conduction and convection paths.

[0032] Effect verification:

[0033] Test Results: Two identical fans were used for motor temperature rise testing. One fan used a traditional external rotor motor, and the other used a heat pipe motor added to the motor housing as described in this invention. Testing was conducted according to existing temperature rise standards. Multiple temperature monitoring points were set at the same locations on the first and second bearing housings of both prototypes. Comparing the test results, the temperatures of the first and second bearings in the traditional motor were 50℃ and 35℃ respectively, with a bearing temperature difference of 15℃. In this invention, the temperatures of the first and second bearings in the heat pipe motor were 50℃ and 40℃ respectively, with a bearing temperature difference of 10℃. The temperature uniformity efficiency was improved by 67%. After adding the heat pipe, the temperature of the upper and lower bearings in the motor became more uniform, and the heat dissipation conditions at the high-heat-generating area of ​​the first bearing were improved. The addition of the heat pipe effectively improved the motor's operating power and bearing life while achieving uniform temperature and heat dissipation.

[0034] The embodiments described above are merely preferred solutions of this utility model and are not intended to limit this utility model in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A motor bearing temperature equalization device based on heat pipe temperature equalization technology, comprising a stator (1) and a rotor (2), wherein the stator has a motor connection seat (11), characterized in that, The motor connector includes a circular tube section (111), a transition section (112), and a disc section (113). The circular tube section and the transition section have at least one hollow bearing seat for mounting bearings. At least one mounting channel (1111) is provided on the outside of the circular tube section (111) and the transition section (112). A heat pipe (3) is embedded and fixed in the mounting channel (1111). The heat pipe (3) is filled with working fluid and contains a capillary structure to realize working fluid circulation.

2. The motor bearing temperature equalization device based on heat pipe temperature equalization technology according to claim 1, characterized in that, The connecting tube section (111) has a first bearing seat (1112) inside, and the transition section (112) has a second bearing seat (1113) inside.

3. The motor bearing temperature equalization device based on heat pipe temperature equalization technology according to claim 1, characterized in that, The heat pipe (3) is connected to the bearing housing through a thermally conductive interface layer (4).

4. The motor bearing temperature equalization device based on heat pipe temperature equalization technology according to claim 3, characterized in that, The thermal interface layer (4) is a metal sintered pad or thermal grease with a thickness of ≤0.5mm.

5. A motor bearing temperature equalization device based on heat pipe temperature equalization technology according to claim 2, characterized in that, The heat pipe (3) includes an evaporation section (31), an insulation section and a condensation section (32). The evaporation section (31) is thermally connected to the first bearing housing (1112), and the condensation section (32) is thermally connected to the second bearing housing (1113).

6. The motor bearing temperature equalization device based on heat pipe temperature equalization technology according to claim 1, characterized in that, The heat pipe (3) is a copper-water working medium gravity-assisted heat pipe with a working temperature range of 40~120℃.

7. The motor bearing temperature equalization device based on heat pipe temperature equalization technology according to claim 1, characterized in that, The mounting channel (1111) has a depth of 1~5mm and matches the shape of the heat pipe (3).

8. The motor bearing temperature equalization device based on heat pipe temperature equalization technology according to claim 1, characterized in that, The heat pipe (3) is fixed axially to the end face of the mounting channel (1111), the evaporation section (31) is in radial contact with the stator, and the condensation section (32) is fixed radially by screws (5).

9. A motor bearing temperature equalization device based on heat pipe temperature equalization technology according to claim 1, characterized in that, The number of heat pipes (3) is determined by the motor load and operating conditions. For motors operating under high load and high temperature, multiple heat pipes (3) can be arranged in parallel around the circumference.

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