DISK TYPE ELASTOMERIC BEARINGS

Disclosed is a disk type elastic bearing. The disk type elastic bearing of the present invention comprises an upper plate which is fixed to the upper part of a bridge and has a slanted flow hole on the center; a lower plate which is fixed on a pier of the bridge and has a flow hole corresponding to the flow hole of the upper plate; an elastic disk which has an installation hole on the center and is installed between the upper and lower plates; and a negative reaction combining unit which is installed by passing through the flow holes and the installation hole and combines the upper and lower plates with the elastic disk therebetween. The negative reaction combining unit is composed of a shear key member which has screw threads on both areas except a center part positioned at the installation hole and is installed by passing through each flow hole and the installation hole such that the center part is positioned at the installation hole; and negative reaction nuts each of which has a circular arc-shaped curved part on one side of the end part corresponding to the slanted inner side of each flow hole and is fastened with each screw thread of the shear key member in each flow hole such that the negative reaction nuts are in point-contact with or in line-contact with the inner side of each flow hole. According to the present invention, negative reaction resistance can be generated when the upper and lower plates vertically move and rotate, and the upper and lower plates smoothly perform vertical movement and rotation in an allowable range since the circular arc-shaped curved parts are formed in the negative reaction nuts to make the negative reaction nuts be in point-contact with or in a line-contact with the inner side of each flow hole, thereby maintaining the negative reaction resistance.