Abstract: A seal for a rolling cutter drill bit is provided. The seal has a ring shaped seal body having an inside diameter and an outside diameter, and a mud lobe and a grease lobe extending from the inside diameter of the seal body. The seal body has an asymmetrical, longitudinal cross-section such that, when positioned in a seal groove of the drill bit and compressed therein under downhole pressure, the mud lobe is maintained in contact with a seal land of the seal groove. The seal body may be provided with a garter spring and/or a textured pattern.

Abstract: A seal for a rolling cutter drill bit is provided. The seal has a ring shaped seal body having an inside diameter and an outside diameter, and a mud lobe and a grease lobe extending from the inside diameter of the seal body. The seal body has an asymmetrical, longitudinal cross-section such that, when positioned in a seal groove of the drill bit and compressed therein under downhole pressure, the mud lobe is maintained in contact with a seal land of the seal groove. The seal body may be provided with a garter spring and/or a textured pattern.

Abstract: The present invention is a self adjusting, volume balanced, single energizer rigid face seal for rolling cutter drill bits with floating journal bearings. Volume balancing is accomplished by utilizing a floating static seal between the rigid face seal ring and the bearing shaft. This floating static seal ring is moved axially within a annular groove by the volume pulses caused by the axial play of the cutter when in operation. At one end of the annular groove the geometry of the rigid seal ring and bearing shaft are set such that the seal assembly achieves volume balance when the bearing is running on its OD. If the bearing is running on its OD, the floating static seal will move from where ever it is in the annular groove by the volume pulses until it reaches the balance volume position.

Abstract: The invention provides a mechanical face seal for rotary rock bits with a novel coil spring energization system that prevents yielding of the coil springs in extreme torque conditions. Within at least one of the coil springs is a cylindrical pin designed to co-act with the spring such that the combination becomes very stiff in the radial direction as the spring extends beyond a certain amount. This prevents the high torque from yielding the springs. When the spring returns to its normal extension, the pin does not interfere with the axial compression of the spring. This combination allows the coil spring energizers of a rotary rock bit mechanical face seal to survive the occasional extreme torque event.