Normal contact analysis for spherical pump based on fractal theory

Spherical pump has a ball-in-socket contact pattern between piston and cylinder. Therefore, traditional Hertz contact theory is not applicable and fractal theory is employed to investigate the conformal contact between piston and cylinder in this paper. The asperities contact on roughness surface is regarded as Hertz contact and friction effects are considered. Besides, the contact coefficient is proposed, which is affected by the structural...