Abstract: A cutter assembly for a tunnel boring machine includes first and second housing mounts each having a plate portion, an abutment flange, and a plurality of spaced seats. A cutter ring assembly is mountable in the housings and includes two or more bridging supports that include a shaft mounting portion and two end portions that abut respective housing mount flanges. The cutter ring axis of rotation is between and parallel to the housing mounts. Separate wedge members are attachable to the housing mounts, and are configured to clamp the end portions of the bridging supports against the associated flanges. In some embodiments removable seat members are provided between the housing mount seats and the wedge members. The housing mounts and removable seats are configured to permit the cutter ring assembly to be inserted inline to the housing mounts.

Abstract: A cutter assembly for a tunnel boring machine includes first and second housing mounts each having a plate portion, an abutment flange, and a plurality of spaced seats. A cutter ring assembly is mountable in the housings and includes two or more bridging supports that include a shaft mounting portion and two end portions that abut respective housing mount flanges. The cutter ring axis of rotation is between and parallel to the housing mounts. Separate wedge members are attachable to the housing mounts, and are configured to clamp the end portions of the bridging supports against the associated flanges. In some embodiments removable seat members are provided between the housing mount seats and the wedge members. The housing mounts and removable seats are configured to permit the cutter ring assembly to be inserted inline to the housing mounts.

Abstract: A pressure-compensated cutter assembly for a tunnel boring machine includes a shaft a cutter ring assembly rotatably mounted on the shaft, and first and second end retainers non-rotatably attached to the shaft. Rotary seal groups, immersed in lubricant, provide a moving seal between the rotating cutter ring assembly and the end retainers. A movable piston member is exposed to ambient pressures, and contacts the lubricant, such that increasing ambient pressure will increase the lubricant pressure, thereby keeping the pressure differential across the seal small. In one embodiment, the piston is a floating retainer portion. In another embodiment, the piston is an annular piston, and in another embodiment, the piston is a plurality of smaller pistons disposed in the first retainer.

Abstract: A pressure-compensated cutter assembly for a tunnel boring machine includes a shaft a cutter ring assembly rotatably mounted on the shaft, and first and second end retainers non-rotatably attached to the shaft. Rotary seal groups, immersed in lubricant, provide a moving seal between the rotating cutter ring assembly and the end retainers. A movable piston member is exposed to ambient pressures, and contacts the lubricant, such that increasing ambient pressure will increase the lubricant pressure, thereby keeping the pressure differential across the seal small. In one embodiment, the piston is a floating retainer portion. In another embodiment, the piston is an annular piston, and in another embodiment, the piston is a plurality of smaller pistons disposed in the first retainer.