Self-heat-dissipation rotary brake based on magnetorheological solid-liquid phase change

Abstract

The invention discloses a self-cooling rotary brake based on magnetorheological solid-liquid phase change, and belongs to the field of magnetorheological fluid braking. The working temperature of the magnetorheological fluid brake is crucial to the braking performance of the magnetorheological fluid brake. The brake is mainly composed of a wind generating set and a magnetorheological fluid brake with a self-function heat dissipation function, in service, a fan turbine (1) drives a rotating shaft (9), a rotor (10), a brake disc (6) and fan blades (15) to rotate under the action of wind power, the rotor and a stator (3) convert wind energy into electric energy, the brake disc immersed in magnetorheological fluid (14) restrains the rotating speed of the rotating shaft, and the fan blades (15) are driven to rotate. And meanwhile, the fan blades at the bottom continuously discharge air from the ventilation holes (11) to the bottom of the brake along the outer surface of the magnetorheological fluid disc shell (13). According to the structure, the working characteristics of the rotary brake are utilized, the draft fan blades are designed at the bottom of the rotating shaft, air flow of the disc containing cylinder containing the magnetorheological fluid is accelerated, and the magnetorheological fluid can be kept at the low temperature without an additional radiator.

Description

Technical Field

[0001] The invention relates to the field of magnetorheological braking, and in particular to the principle and design method of a self-heat dissipating rotary brake based on magnetorheological solid-liquid phase change. Background Art

[0002] A wind turbine is a device that can convert wind energy into electrical energy. Studies have shown that the shaft speed of a wind turbine is linearly related to the external wind speed. When the wind speed reaches 42m / s, the shaft speed of the turbine generator exceeds 20,000r / min, which may cause the key components of the wind turbine, such as bearings and rotors, to undergo huge wear in a short period of time, which is very likely to cause damage to the wind turbine and cause huge economic losses. Therefore, in practical applications, the speed of the wind turbine must be effectively controlled to ensure that it does not exceed the specified value. This protective measure helps to protect the stable operation of the wind turbine and extend its service life.

[0003] Magnetorheological fluid is a controllable solid-liquid phase change fluid composed of magnetic particles and base carrier fluid. Under normal conditions, it appears as a suspension with low viscosity Newtonian fluid properties. Under the action of a strong magnetic field, the suspended particles change from magnetic neutrality to strong magnetism due to magnetic induction, and interact with each other to form a chain or columnar structure, which instantly changes from liquid to viscoplastic, and the rheological properties change dramatically, showing high viscosity and low fluidity Bingham fluid properties.

[0004] Magnetorheological fluid brake is a mechanical device that uses electromagnetic coils to control the phase change characteristics of magnetorheological fluid to achieve control of braking torque. After research and analysis, a wind turbine with a self-heating rotary brake based on magnetorheological solid-liquid phase change can effectively suppress the shaft speed of the wind turbine, and accurately and efficiently control the shaft speed through the magnetorheological brake at low and high wind speeds. However, the solid-liquid phase change performance of magnetorheological fluid materials will decrease with increasing temperature. During the continuous service of the brake designed based on magnetorheological fluid, coil heating and mechanical friction heat will inevitably lead to a continuous increase in the temperature of the magnetorheological fluid. Due to the increase in the temperature of the magnetorheological fluid, the torque, control accuracy and other performance of the magnetorheological fluid brake will decrease. Under continuous high wind speeds, it is impossible to maintain effective control of the shaft speed of the wind turbine, so it is urgent to improve the structure to improve its heat dissipation capacity. Summary of the invention

[0005] In response to the above problems, the present invention discloses a self-heating rotary brake based on magnetorheological solid-liquid phase change, and the technical problems to be solved are: improving the heat dissipation capacity of the rotary magnetorheological fluid brake during service, enhancing the reliability and stability of the magnetorheological fluid brake during service, and maintaining the magnetorheological fluid brake's efficient braking of the rotating shaft under continuous high wind speeds of the wind turbine.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] The present invention discloses a self-heating rotary brake based on magnetorheological solid-liquid phase change, with an outer diameter of Φ26mm and a height of 34mm. The self-heating rotary magnetorheological fluid brake mainly consists of two parts: a rotary wind turbine generator and a self-heating magnetorheological fluid brake; the rotary wind turbine generator includes a fan turbine, a rotating shaft, a deep groove ball bearing, an upper end cover, a stator coil, a rotor magnet, and a shell. The fan turbine is fixedly connected to the rotating shaft, the inner ring of the deep groove ball bearing is tightly matched with the rotating shaft, and the outer ring of the deep groove ball shaft is nested in the upper end cover. The upper end cover and the top of the shell are assembled with threads, the rotor magnet is fixed on the rotating shaft, the stator coil is placed in the middle of the rotor magnet and fixed to the shell, and the stator coil and the rotor magnet are arranged in the space cavity surrounded by the shell and the upper end cover;

[0008] The self-functional heat dissipating magnetorheological fluid brake includes an electromagnetic coil, magnetorheological fluid, a brake disc, a tail cover, a deep groove ball bearing, a rotating shaft, a shell air inlet, an air vent, a disc containing cylinder, and an exhaust fan blade. The electromagnetic coil 5 is distributed in the upper and lower parts of the disc containing cylinder 13. The disc containing cylinder contains the magnetorheological fluid 14 and the brake disc 6, and is fixed to the shell 4 at the same time. The rotating shaft 9 is penetrated by the deep groove ball bearing, and the brake disc is fixedly connected to the rotating shaft. The shell air inlet 11 is a hole drilled between the shell and the electromagnetic coil, and the air vent 12 is a hole drilled at the fixing position of the disc containing cylinder and the shell. The exhaust fan blade 15 is fixedly connected to the bottom end of the rotating shaft and is located in the middle through groove of the tail cover.

[0009] The turbine drives the shaft to rotate under the action of wind, so that the rotor and stator connected to the shaft produce relative motion to generate electrical energy. The brake disc connected to the shaft is immersed in magnetorheological fluid. The electromagnetic coil applies current to control the phase change of magnetorheological fluid in the disc containing cylinder to slow down the shaft. The end of the shaft is connected to the exhaust fan blade to rotate. There is an air inlet on the shell, which continuously draws air from the air inlet of the shell and discharges it at the tail of the brake after passing through the disc containing cylinder.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1. The invention discloses a self-cooling rotary brake based on magnetorheological solid-liquid phase change, which is different from the liquid-cooled magnetorheological fluid brake that uses an external water pump to extract liquid cooling water. By adding an exhaust fan blade at the end of the rotating shaft, the magnetorheological fluid brake is self-cooled by air, without the need for an additional heat dissipation device.

[0012] 2. In a self-functional heat-dissipating rotary magnetorheological fluid brake disclosed by the present invention, the magnetic field coils are distributed on the upper and lower sides of the disc containing cylinder, which is beneficial to the liquid-to-solid phase change of the magnetorheological fluid, and utilizes the liquid-to-solid controllability of the magnetorheological fluid to generate braking torque, thereby achieving precise control of the shaft speed and rapid response.

[0013] 3. The present invention is small in size, light in weight, simple and compact in structure, easy to disassemble and maintain, low in processing difficulty, and suitable for miniaturization. At the same time, the structural materials are mainly copper and aluminum, which are rich in sources, huge in stock, and low in production cost. At the same time, the manufacturing process of the relevant structural main body used is mature, which is an economically feasible solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The figure is a schematic diagram of the overall structure of a self-heating rotary magnetorheological fluid brake.

[0015] Among them: 1-fan turbine, 2-upper end cover, 3-stator coil, 4-housing, 5-electromagnetic coil, 6-brake disc, 7-tail end cover, 8-deep groove ball bearing, 9-rotating shaft, 10-rotor magnet, 11-housing air inlet, 12-vent, 13-disc receiving tube, 14-magnetorheological fluid, 15-exhaust fan blade. DETAILED DESCRIPTION

[0016] In order to better illustrate the operation and design purpose of the present invention, the invention content is further described below with reference to the accompanying drawings and operating examples.

[0017] Embodiment 1:

[0018] This embodiment is a self-heating rotary brake based on magnetorheological solid-liquid phase change. Figure 1 As shown. The self-functional heat dissipation rotary magnetorheological fluid brake is mainly composed of two parts: a rotary wind turbine generator and a self-functional heat dissipation magnetorheological fluid brake. In the rotary wind turbine generator, the fan turbine 1 continues to rotate at a high speed under the action of wind, and the fan turbine is fixedly connected to the rotating shaft 9, while the rotor magnet 10 is fixedly connected to the rotating shaft. Therefore, relative motion is generated between the fan turbine and the stator coil 3. According to Faraday's law of electromagnetic induction, the stator coil generates an induced electromotive force, and the rotary wind turbine generator outputs electrical energy. In the face of high-speed working conditions, a self-functional heat dissipation magnetorheological fluid brake is required to control the speed.

[0019] In the self-functional heat dissipation magnetorheological fluid brake structure, the electromagnetic coil 5 generates a magnetic field by controlling the current. Due to the characteristics of the magnetorheological fluid 14 itself, when the magnetic field passes through the magnetorheological fluid gap in the disc containing cylinder 13, the magnetorheological fluid undergoes a corresponding liquid-solid phase change, and its damping torque on the brake disc 6 is increased, thereby reducing the rotation speed of the shaft. At the same time, the exhaust fan blades at the tail continue to inhale air from the air inlet 11 of the shell, and the air flows along the outer surface of the disc containing cylinder and is finally discharged at the tail of the brake, accelerating the air flow inside the magnetorheological fluid brake, taking away the heat generated by the friction of the magnetorheological fluid in the disc containing cylinder and the electromagnetic coil, reducing the working temperature of the magnetorheological fluid, and allowing the magnetorheological fluid brake to maintain a high performance during service. The advantage of this structure is that there is no need to use an additional water pump to extract water to cool and dissipate the water-cooled magnetorheological fluid brake like the traditional method, which is costly and complicated to operate. On the contrary, the structure realizes the natural air cooling and heat dissipation of the magnetorheological fluid brake by adding an exhaust fan blade at the end of the shaft, thereby avoiding the need for additional heat dissipation devices.

[0020] Finally, it should be noted that the specific description described above further illustrates the purpose, technical solutions and beneficial effects of the invention in detail, with the aim of helping to further understand the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A self-heating rotary brake based on magnetorheological solid-liquid phase change, characterized in that It consists of two parts: a rotary wind turbine generator and a self-functional heat dissipating magnetorheological fluid brake; the rotary wind turbine generator includes a fan turbine, a rotating shaft, a deep groove ball bearing, an upper end cover, a stator coil, a rotor magnet, and a shell, the fan turbine is fixedly connected to the rotating shaft, the inner ring of the deep groove ball bearing is tightly matched with the rotating shaft, and the outer ring of the deep groove ball shaft is nested in the upper end cover, the upper end cover and the top of the shell are assembled with threads, the rotor magnet is fixed on the rotating shaft, the stator coil is placed in the middle of the rotor magnet and fixed to the shell, and the stator coil and the rotor magnet are arranged in the space cavity surrounded by the object and the upper end cover; The brake includes an electromagnetic coil, a magnetorheological fluid, a brake disc, a tail cover, a shell air inlet, an air vent, a disc containing cylinder, and an exhaust fan blade, wherein the electromagnetic coil is distributed above and below the disc containing cylinder; the disc containing cylinder contains the magnetorheological fluid and the brake disc, and is fixed to the shell, and the deep groove ball bearing is used to allow the rotating shaft to pass through; the brake disc is fixedly connected to the rotating shaft, the shell air inlet is a hole drilled between the shell and the electromagnetic coil, the air vent is a hole drilled at the fixing position of the disc containing cylinder and the shell, and the exhaust fan blade is fixedly connected to the bottom end of the rotating shaft and is located in the middle through groove of the tail cover.

2. The self-heating rotary brake based on magnetorheological solid-liquid phase change according to claim 1 is characterized in that: The shell air inlet designed in the middle of the shell is a space flow channel with an air inlet left between the electromagnetic coil and the shell, and the hollow area of ​​the electromagnetic coil at the bottom serves as an air outlet.

3. The self-heating rotary brake based on magnetorheological solid-liquid phase change according to claim 1 is characterized in that: A cavity is reserved in the middle of the tail end cover for accommodating the exhaust fan blades at the tail end of the rotating shaft. The exhaust fan blades are located at the air outlet, and bottom air is extracted while the rotating shaft rotates, thereby accelerating the internal air flow.

4. The self-heating rotary brake based on magnetorheological solid-liquid phase change according to claim 1 is characterized in that: The fan turbine in the rotary wind turbine generator rotates continuously under the action of wind, the fan turbine is fixedly connected to the rotating shaft, and the rotor magnet is fixedly connected to the rotating shaft; relative motion is generated between the fan turbine and the stator coil, the stator coil generates induced electromotive force, and the rotary wind turbine generator outputs electrical energy; The turbine drives the shaft to rotate under the action of wind, so that the rotor and stator connected to the shaft produce relative motion to generate electrical energy. The brake disc connected to the shaft is immersed in magnetorheological fluid. The electromagnetic coil applies current to control the solid-liquid phase change of the magnetorheological fluid in the disc containing cylinder to slow down the shaft. The end of the shaft is connected to the exhaust fan blade to rotate. There is an air inlet on the shell, which continuously draws air from the air inlet of the shell and discharges it at the tail of the brake after passing along the disc containing cylinder.

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