Electric spindle heat pipe cooling system based on high speed machine tool

As a highly efficient heat transfer element, heat pipes have characteristics different from other heat transfer components. Here, the technology of heat pipe is proposed for the cooling of high-speed machine tool electric spindle, mainly because the following characteristics of the heat pipe provide feasibility for the electric spindle cooling control:

(1) Efficient thermal conductivity. The inside of the heat pipe mainly relies on the working liquid vapor and liquid phase to change heat transfer, and the thermal resistance is small, so it has high thermal conductivity. Compared to metals such as silver, copper, and aluminum, heat pipes per unit weight can transfer several orders of magnitude more heat. Therefore, some people call the heat pipe a hot "superconductor".

(2) The thermal responsiveness is fast. Since the inside of the heat pipe is vacuum, the pressure is small, so the temperature difference of the start of the heat pipe is small. As long as the temperature of the evaporation section is slightly higher than the temperature of the condensation section, the heat pipe responds quickly, adjusting the temperature difference between the temperature of the evaporation section and the temperature of the condensation section.

(3) Diversity of structural shapes. The basic structure of the pulsating heat pipe can be changed according to the conditions of the heat source and the cold source, and the positions of heating and cooling can be arbitrarily selected, so that the adaptability is greatly enhanced, and the field of application thereof is also expanded.

(4) The temperature distribution inside the tube is very uniform. The surface temperature of the heat pipe is controlled by the temperature of the steam in the vacuum, and the heat resistance of each part inside the heat pipe is small, and the temperature does not change much. When the heating amount changes, the temperature of the evaporation section and the condensation section of the heat pipe also changes uniformly. This isothermality has little to do with the shape and size of the heat pipe. For a one-meter long heat pipe, the temperature difference between the evaporation section and the condensation section may be less than 1 °C.

(5) The thermal density can vary as needed. It is possible to input heat with a smaller evaporation section, heat with a larger condensation section, or input heat with a larger evaporation section, and output heat with a smaller condensation section.