a bearing device of a rotary cylinder for a magnetic head includes a fixed shaft and a sleeve rotatably supported about the fixed shaft through a radial bearing . a thrust receiver secured to one axial end of the sleeve has a convex spherical surface at the side confronting the fixed shaft , and a concave spherical surface is formed on an end surface of the fixed shaft confronting the convex spherical surface . a radius of curvature of the concave spherical surface is larger than a radius of curvature of the convex spherical surface of the thrust receiver .