A scroll type fluid machinery provided with a slide type radius of revolution variable mechanism prevents unilateral working of a rotating bearing 23 due to tilted rotation of a drive bushing 21 and a balance weight 27 fixed thereto. A bolt 41 for regulating tilted rotation is projected at an inner end of a rotary shaft 7, a shaft portion 41a therefor penetrates through a hole 42 bored in the balance weight 27, and a bearing surface 41c of a head 41b thereof is brought into slidable contact with the inner end surface of the balance weight 27. When the radius of revolution is varied at the time of revolution in a solar motion of a revolving scroll 14, an eccentric driving pin 25 slides in a slide groove 24 and the shaft portion 41a of the bolt 41 slides in hole 42 at the same time. In the interim, the bearing surface 41c of the head into slidable contact with the inner end surface of the balance weight 27, thereby to suppress tilted rotation of the balance weight 27.