Sweat cooling structure and heat dissipation method for robot joint motor

Abstract

The invention discloses a sweating cooling structure for a robot joint motor and a heat dissipation method in the field of robot equipment. The sweating cooling structure comprises a motor, a speed reducer and a fan, a waterproof layer, a water absorption layer and a protective layer are sequentially arranged on the outer wall of the motor and the outer wall of the speed reducer from inside to outside, the water absorption layer is made of hydrogel, and dense holes are formed in the protective layer so that the hydrogel can make contact with air. When the temperature of the motor is not high, the fan is adopted for cooling, and when the temperature is high, the fan and water evaporation heat dissipation are adopted for cooling at the same time, so that heat is quickly absorbed, discharged and conducted, and temperature rise caused by excessive instantaneous power of the joint motor is prevented. The hydrogel serves as a sweating and cooling material, water can be automatically supplemented from air when the temperature is not high, an additional water supplementing device is not needed, and the hydrogel can be recycled; besides, on the basis of sweating cooling, a fan with small power can be selected for air cooling, and the problem that noise is too large due to a high-power fan is solved.

Description

Technical Field

[0001] The present invention relates to the field of robot equipment, and in particular to a sweat cooling structure and a heat dissipation method for a robot joint motor. Background Art

[0002] At present, with the advancement of science and technology, humanoid robots are becoming more and more popular. As the core power component of humanoid robots, joint motors directly determine the movement accuracy, flexibility and reliability of humanoid robots. Joint motors generate a lot of heat when working, and the heat dissipation space inside the robot joints is limited, which can easily lead to motor temperature rise, reduced motor performance, and even freezes. There are currently two main ways to dissipate heat for joint motors: air cooling and liquid cooling. For example, patent documents with application numbers CN201911248760.3, CN202220143489.8, and CN201921779819.7 disclose solutions for cooling joint motors by liquid. The main problem is that the sealing requirements of the structure are high, and additional water replenishment or water circulation systems are required. The structure is relatively complex and the cost is high. Patent documents with application numbers CN201821343700.0, CN202311775178.9 and CN202310271608.7 disclose solutions for cooling joint motors by air, that is, mainly cooling by blowing air from a fan. The cooling effect is limited in actual application, and the use of a high-power fan will cause high noise. Summary of the Invention

[0003] In order to overcome the above-mentioned deficiencies in the existing robot joint motor cooling method, the technical problem to be solved by the present invention is to provide a transpiring cooling structure and heat dissipation method for robot joint motors that combines air cooling and transpiring cooling technology.

[0004] The technical solution adopted by the present invention to solve its technical problem is: A sweating cooling structure for a robot joint motor includes a motor, a reducer connected to the motor's output shaft, and a fan located at the end of the motor away from the reducer. The outer walls of the motor and reducer are provided with a waterproof layer, a water-absorbing layer, and a protective layer from the inside to the outside. The water-absorbing layer is made of hydrogel, and the protective layer is provided with dense holes to allow the hydrogel to come into contact with the air.

[0005] Furthermore, the motor is arranged in the shell, and a front cover and a rear cover are respectively provided at the front and rear ends of the shell, the reducer is arranged in the front cover, and a drive board electrically connected to the motor is provided in the rear cover, and an encoder is provided on the drive board, the waterproof layer is wrapped on the outer walls of the shell and the front cover, and the fan is arranged on the outside of the bottom of the rear cover.

[0006] Furthermore, heat dissipation fins are provided between the outer side of the bottom of the rear cover and the fan.

[0007] Furthermore, a heat dissipation cover is provided at the rear end of the shell, and the heat dissipation fins and fan are located inside the heat dissipation cover. A heat dissipation bottom hole is provided at the bottom of the heat dissipation cover, and a heat dissipation side hole is provided on the side of the heat dissipation cover corresponding to the heat dissipation fins.

[0008] Furthermore, the waterproof layer is a polytetrafluoroethylene film, a polyimide film, a TPE film or a TPU film.

[0009] Furthermore, the protective layer is made of PC material.

[0010] Furthermore, a temperature sensor is provided on the driving board, and the temperature sensor is electrically connected to the fan.

[0011] A heat dissipation method for a robot joint motor includes the aforementioned sweating cooling structure for the robot joint motor and also includes the following control logic: If the temperature feedback from the temperature sensor is less than T 1, the fan cooling is not started; If the temperature feedback from the temperature sensor ≥ T 1. Start the fan to dissipate heat; If the temperature sensor feedback temperature ≥ T 2. Use fans and the evaporation of water in the hydrogel to dissipate heat; in, T 1 and T 2The range of change is 30-80℃, and T 1< T 2, T 2 is the temperature caused by the instantaneous peak power of the motor, which is also the water absorption and release transition temperature of the hydrogel.

[0012] Furthermore, the hydrogel is a hydrogel composed of a salt-resistant hydrogel and a hygroscopic salt solution, and the water absorption and release transition temperature of the hydrogel is adjusted by adjusting the proportion of the hygroscopic salt solution or the proportion of the hydrophilic groups, so that the transition temperature is T 2 are the same.

[0013] Furthermore, the hygroscopic salt solution is a lithium bromide solution, a lithium chloride solution or a calcium chloride solution, and the hygroscopic salt solution accounts for 35-45% of the total mass of the hydrogel.

[0014] The beneficial effects of the present invention are: the present invention combines air cooling and sweat cooling technology. When the temperature of the motor is not high, fan cooling is adopted. When the temperature is high, fan and water evaporation heat dissipation are adopted simultaneously for cooling, thereby quickly absorbing and dissipating heat, preventing the instantaneous excessive power of the joint motor from causing temperature rise and causing device damage; the present invention uses hydrogel as a sweat cooling material, which can automatically replenish water from the air when the temperature is not high, does not require an additional water replenishment device, and can be recycled, thereby simplifying the joint structure; in addition, on the basis of sweat cooling, a fan with lower power can be selected for air cooling to avoid the problem of excessive noise caused by a high-power fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present invention.

[0016] Marked in the figure are: 1- reducer, 2- motor, 3- drive board, 4- encoder, 5- front cover, 6- rear cover, 7- housing, 8- waterproof layer, 9- water absorption layer, 10- protective layer, 11- heat sink fins, 12- fan, 13- heat sink cover, 31- temperature sensor, 131- heat sink bottom hole, 132- heat sink side hole. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] It should be noted that if directional terms are used in this disclosure, such as "up," "down," "left," "right," "forward," and "backward," these are intended to facilitate the description of the relative positions of components and are not intended to specify the absolute positions of the components or the positional relationships between them. They are used only to explain the relative positions and movement of components in a specific posture. If the posture changes, the directional terms will change accordingly. If terms referring to quantity are used in this disclosure, such as "plurality," "multiple," and "several," these specifically refer to two or more.

[0019] like Figure 1As shown, the present invention provides a sweat cooling structure for a robot joint motor, comprising a motor 2, a reducer 1 connected to the output shaft of the motor 2, and a fan 12 located at the end of the motor 2 away from the reducer 1. The outer walls of the motor 2 and the reducer 1 are provided with a waterproof layer 8, a water-absorbing layer 9, and a protective layer 10 from the inside to the outside. The water-absorbing layer 9 is made of hydrogel, and the protective layer 10 is provided with dense holes to allow the hydrogel to contact the air. The waterproof layer 8 is mainly used to prevent moisture in the water-absorbing layer 9 from entering the motor 2 and the reducer 1. It can be made of a thin waterproof material such as polytetrafluoroethylene film, polyimide film, TPE film or TPU film to avoid using too thick materials that affect the heat transfer between the motor 2 and the water-absorbing layer 9. The protective layer 10 is mainly used to protect the internal water-absorbing layer 9 from external mechanical damage or dust pollution. It can be made of plastic materials such as PC. The dense holes on the side wall can be drilled or injection molded. In addition, the protective layer 10 must be fixedly connected to the motor 2 or other external structures to ensure that the internal hydrogel is uniform and does not deform.

[0020] The present invention combines air cooling and transpiration cooling technologies. When the motor 2 is not hot, fan 12 is used for cooling. When the temperature is high, fan 12 and the evaporation of water from the water-absorbing layer 9 are used simultaneously to dissipate heat. This rapidly absorbs and dissipates heat, preventing the joint motor from overheating due to transient power overload, which could cause temperature rise and damage. Hydrogel is used as the transpiration cooling material, which automatically replenishes water from the air when the temperature is low, eliminating the need for additional water replenishment devices and allowing for recycling, thus simplifying the joint structure. Furthermore, while transpiration cooling is in place, a lower-power fan can be used for air cooling, avoiding the excessive noise caused by a high-power fan.

[0021] The joint motor generally combines the motor 2 and the reducer 1 as well as the matching drive plate 3 and encoder 4, and the motor 2 usually adopts a frameless torque motor. Therefore, in order to improve the integrity of the joint motor and play a role in dust protection, the motor 2 is arranged in the shell 7, and the front and rear ends of the shell 7 are respectively provided with a front cover 5 and a rear cover 6, and the front cover 5 and the rear cover 6 can be installed on the shell 7 by threaded connection or snap connection. The shell 7, the front cover 5 and the rear cover 6 are all made of metal, which is convenient for conducting heat outward. The reducer 1 is arranged in the front cover 5, and the rear cover 6 is provided with a drive plate 3 electrically connected to the motor 2 and the fan 12, and the drive plate 3 is provided with an encoder 4. The drive plate 3 is a control circuit board, which is used to control the operation of the motor 2 and the fan 12, and the encoder 4 is used to control the rotation angle of the output shaft of the motor 2. The waterproof layer 8 is wrapped on the outer wall of the shell 7 and the front cover 5, and the protective layer 10 can be fixedly connected to the shell 7. The fan 12 is arranged on the outside of the bottom of the rear cover 6.

[0022] In order to improve the air cooling effect, a heat dissipation fin 11 is further provided between the bottom outer side of the rear cover 6 and the fan 12. The heat dissipation fin 11 can be made of copper sheets with good thermal conductivity and welded to the rear cover 6 to increase the heat dissipation area of ​​the rear cover 6, thereby improving the air cooling effect.

[0023] To protect the fan 12, a heat dissipation cover 13 is provided at the rear end of the housing 7. The heat dissipation fins 11 and fan 12 are both located within the heat dissipation cover 13. A heat dissipation bottom hole 131 is provided at the bottom of the heat dissipation cover 13, and heat dissipation side holes 132 are provided on the side of the heat dissipation cover 13 at positions corresponding to the heat dissipation fins 11. When the fan 12 is operating, external air enters the heat dissipation cover 13 through the heat dissipation side holes 132, passes through the heat dissipation fins 11, removes heat, and is then discharged through the heat dissipation bottom holes 131. The heat dissipation side holes 132 can be set smaller to avoid the inhalation of excessive dust and other impurities, while the heat dissipation bottom hole 131 can be set larger to allow for faster discharge of hot air, thereby improving the heat dissipation effect.

[0024] In addition, in order to facilitate the control of the operating timing of the fan 12, a temperature sensor 31 is provided on the driving board 3. The temperature sensor 31 is electrically connected to the fan 12 through the driving board 3. The driving board 3 controls the start and stop of the fan 12 according to the temperature feedback from the temperature sensor 31.

[0025] Furthermore, with respect to the above-mentioned sweating cooling structure for the robot joint motor, in order to achieve optimal control of the joint motor temperature, the present invention also provides a heat dissipation method for the robot joint motor, which mainly includes the following control logic: If the temperature feedback from the temperature sensor 31 is less than T 1, the fan 12 is not started for heat dissipation; If the temperature feedback from the temperature sensor 31 ≥ T 1. Start the fan 12 to dissipate heat; If the temperature sensor 31 feedback temperature ≥ T 2. Dissipate heat by using the fan 12 and the evaporation of water in the hydrogel; in, T 1 and T 2The range of change is 30-80℃, and T 1< T 2, T 2 is the temperature caused by the instantaneous peak power of motor 2, which is also the water absorption and release transition temperature of the hydrogel.

[0026] The hydrogel is composed of a salt-resistant gel and a hygroscopic salt solution, and the water absorption and release transition temperature of the hydrogel is adjusted by adjusting the proportion of the hygroscopic salt solution or the proportion of the hydrophilic groups, so that the transition temperature is equal to T 2Same or as close as possible T2. According to the actual working condition analysis of the robot joint motor, the joint motor does not work for a long time at peak power, so T 2 will not be very high, usually around 50°C, so the hygroscopic salt solution can be lithium bromide solution, lithium chloride solution or calcium chloride solution. The hygroscopic salt solution accounts for 35-45% of the total mass of the hydrogel to meet the sweating and heat dissipation needs of the joint motor under most working conditions.

Claims

1. A sweat cooling structure for a robot joint motor, comprising a motor (2), a reducer (1) connected to an output shaft of the motor (2), and a fan (12) located at an end of the motor (2) away from the reducer (1), characterized in that: The outer walls of the motor (2) and the reducer (1) are provided with a waterproof layer (8), a water-absorbing layer (9) and a protective layer (10) in sequence from the inside to the outside. The water-absorbing layer (9) is made of hydrogel, and the protective layer (10) is provided with dense holes to allow the hydrogel to contact the air.

2. The sweating cooling structure for a robot joint motor according to claim 1, characterized in that: The motor (2) is arranged in a housing (7), and a front cover (5) and a rear cover (6) are provided at the front and rear ends of the housing (7), respectively. The reducer (1) is arranged in the front cover (5), and a drive plate (3) electrically connected to the motor (2) and the fan (12) is provided in the rear cover (6). An encoder (4) is provided on the drive plate (3), and the waterproof layer (8) is wrapped around the outer walls of the housing (7) and the front cover (5). The fan (12) is arranged on the outer side of the bottom of the rear cover (6).

3. The sweating cooling structure for a robot joint motor according to claim 2, characterized in that: A heat dissipation fin (11) is further provided between the outer side of the bottom of the rear cover (6) and the fan (12).

4. The sweating cooling structure for a robot joint motor according to claim 3, characterized in that: A heat dissipation cover plate (13) is further provided at the rear end of the housing (7), the heat dissipation fins (11) and the fan (12) are both located within the heat dissipation cover plate (13), a heat dissipation bottom hole (131) is provided at the bottom of the heat dissipation cover plate (13), and heat dissipation side holes (132) are provided at positions on the side of the heat dissipation cover plate (13) corresponding to the heat dissipation fins (11).

5. The sweating cooling structure for a robot joint motor according to claim 1, characterized in that: The waterproof layer (8) is a polytetrafluoroethylene film, a polyimide film, a TPE film or a TPU film.

6. The sweating cooling structure for a robot joint motor according to claim 1, characterized in that: The protective layer (10) is made of PC material.

7. The sweating cooling structure for a robot joint motor according to claim 2, 3 or 4, characterized in that: A temperature sensor (31) is provided on the driving board (3), and the temperature sensor (31) is electrically connected to the fan (12) through the driving board (3).

8. A heat dissipation method for a robot joint motor, characterized in that: The sweating cooling structure for a robot joint motor according to claim 7 further includes the following control logic: If the temperature feedback from the temperature sensor (31) is less than T 1, the fan (12) is not started to dissipate heat; If the temperature feedback from the temperature sensor (31) ≥ T 1. Start the fan (12) to dissipate heat; If the feedback temperature from the temperature sensor (31) ≥ T 2. Using the fan (12) and the evaporation of water in the hydrogel to dissipate heat; in, T 1 and T 2The range of change is 30-80℃, and T 1< T 2, T 2 is the temperature caused by the instantaneous peak power of the motor (2), which is also the water absorption and release transition temperature of the hydrogel.

9. The heat dissipation method for a robot joint motor according to claim 8, wherein: The hydrogel is composed of a salt-resistant hydrogel and a hygroscopic salt solution. The water absorption and release transition temperature of the hydrogel is adjusted by adjusting the proportion of the hygroscopic salt solution or the proportion of the hydrophilic groups. T 2 are the same.

10. The heat dissipation method for a robot joint motor according to claim 9, wherein: The hygroscopic salt solution is lithium bromide solution, lithium chloride solution or calcium chloride solution, and the hygroscopic salt solution accounts for 35-45% of the total mass of the hydrogel.

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