Abstract: A rotatable mixing head assembly attachable to a boom of an excavating machine comprising a torque tube supporting a motor mounted within the torque tube, and a mounting assembly for attaching the rotatable mixing head assembly to the boom of an excavating machine. The device has a rotatable mixing head supported by a drive shaft and driven by the motor, which mixing head supports mixing arms and other implements. The rotating casing of the mixing head defines a cavity. Grease is forced through the cavity and out a seal engaging the casing, thus keeping contaminants from the bearings. A water spray may be provided for suppressing dust. A header is provided for delivering dry or liquid reagents to the mixing site.

Abstract: A mixing head assembly attachable to a boom of an excavating machine comprising a torque tube supporting a motor mounted within the torque tube, and a mounting assembly for attaching the mixing head assembly to the boom of an excavating machine. The device has a rotatable mixing head supported by a drive shaft and driven by the motor, which mixing head supports mixing arms and other implements. The rotating casing of the mixing head defines a first cavity enclosing a bearing housing, which bearing housing defines a second cavity. The bearing housing is stationary with respect to the torque tube. Grease is forced through the first cavity and out a seal engaging the casing, thus keeping contaminants from the bearings. Oil is forced through the second cavity and recirculated to lubricate the bearings and prevent contaminates from entering the bearings. A water spray may be provided for suppressing dust. A header is provided for delivering dry or liquid reagents to the mixing site.