BOTTOM COLLAR VIBRATION DAMPENER Russian patent published in 1994 - IPC

FIELD: vibration dampening in drilling oil and gas wells. SUBSTANCE: dampener has body 1 accommodating stepped shaft forming hollow together with its smaller step 6 and body. Hollow 7 accommodates flexible member in form of rows of rubber balls 8 located between disks 9 and 10 coinciding in axis of dampener and has clearance. Balls of each row separated from one another and from disks 9 and 10 with separating disks 24. Made above hollow containing flexible member are holes with total area larger or equal to area of said clearance. EFFECT: higher efficiency. 2 cl, 3 dwg