the portion of the inner circumferential surface of the support element 46 that faces the radial dynamic pressure generating grooves 48 and constitutes a radial bearing 50 portion the dynamic pressure generated as such acts as a load bearing pressure the process of blanking the dynamic pressure acting face may be carried out by such means as compressing an oil impregnated metallic material impregnation hardening a synthetic polymer or plating forming the support element 46 from the porous oil impregnated metallic material as described above enables communication of the radial bearing 50 portion with the outer atmosphere via holes within the oil impregnated metallic material this therefore renders unnecessary a separate communicating channel or like configuration for communicating the radial bearing portion 50 with the outer air like the first embodiment of the present invention illustrated in fig4 when filling with the lubricating fluid 14 or when the motor is rotating bubbles generated within the lubricating fluid 14 sustained in the radial bearing portion 50 are discharged to the bearing exterior through the holes this prevents the lubricating fluid 14 from leaking out to the exterior of the bearing by due to temperature elevation in the motor thermal expansion of the bubbles thus the motor configuration is further simplified which serves in cost reduction further blanking the dynamic pressure acting face of the support element.