Start-Up Process of High-Speed Micro-Grooved Pumping Seal for New Energy Vehicles

With the growing global demand for clean energy, new energy vehicles are a key focus in the automotive industry. This paper investigates the micro-grooved pumping seal used in such vehicles, using a custom Python computational programme to study the start-up behaviour of a non-contact oil–gas two-phase micro-grooved seal. The research explores the balance of forces during start-up, employing fractal theory for surface contact force calculations and solving the two-phase laminar Reynolds equation by the finite difference method. The results show that high-speed micro-grooved seals perform well under typical conditions for new energy vehicles. When film thickness is below a critical value, fractal dimension and characteristic length influence the initial thickness. Above the critical value, film thickness increases non-linearly with rotational speed, whereas the leakage rate decreases linearly. Critical rotational speed decreases non-linearly with the oil–gas ratio, peaking at an oil–gas ratio of 0.06. Both critical speed and leakage rate increase linearly and non-linearly with pressure and temperature, respectively. The study highlights the boundary-line where leakage transitions to pumping, providing valuable guidance for optimising seal design in new energy vehicles.