A ring gear arrangement , comprising: a ring gear mount comprising: a ring gear having at least one internal gear for interaction with one or more gear wheels, the ring gear having a principal axis about which the one or more gear wheels rotate; a ring gear stator ; and, a plurality of couplings which locate the ring gear within the ring gear stator , each coupling having a resiliently deformable connection , characterised in that each coupling has a drive arm connected to the ring gear , the resiliently deformable connection is a torsion bar , the longitudinal axis of the torsion bar lies parallel to the principal axis, a first end of the drive arm connects to the ring gear and a second end of the drive arm connects to the torsion bar at a torqued end, and the opposing end of the torsion bar connects to a static structure , the drive arm includes a first drive member and a second drive member in series connection between the ring gear and the ring gear stator , the first end of the first drive member is pivotably connected to a radial flange of a mounting plate of the ring gear and extends to a pivot connection with the second drive member , the second drive member extends from the pivot connection towards a second end which is fixedly attached to the torsion bar , wherein the drive arm is movable between a first position in which the ring gear is in a rest position and a second position in which the ring gear has undergone some radial or rotational movement relative to the ring gear stator , wherein movement of the drive arm from the first position to the second position loads the resiliently deformable connection against the ring gear , wherein the resiliently deformable connection biases the drive arm to return to the first position when in the second position. a ring gear having at least one internal gear for interaction with one or more gear wheels, the ring gear having a principal axis about which the one or more gear wheels rotate; a ring gear stator ; and, a plurality of couplings which locate the ring gear within the ring gear stator , each coupling having a resiliently deformable connection , characterised in that each coupling has a drive arm connected to the ring gear , the resiliently deformable connection is a torsion bar , the longitudinal axis of the torsion bar lies parallel to the principal axis, a first end of the drive arm connects to the ring gear and a second end of the drive arm connects to the torsion bar at a torqued end, and the opposing end of the torsion bar connects to a static structure , the drive arm includes a first drive member and a second drive member in series connection between the ring gear and the ring gear stator , the first end of the first drive member is pivotably connected to a radial flange of a mounting plate of the ring gear and extends to a pivot connection with the second drive member , the second drive member extends from the pivot connection towards a second end which is fixedly attached to the torsion bar , wherein the drive arm is movable between a first position in which the ring gear is in a rest position and a second position in which the ring gear has undergone some radial or rotational movement relative to the ring gear stator , wherein movement of the drive arm from the first position to the second position loads the resiliently deformable connection against the ring gear , wherein the resiliently deformable connection biases the drive arm to return to the first position when in the second position. <EOS>