Abstract: A centrifugal incompressible fluid pump comprising a casing with a pump inlet and a pump outlet, the casing housing an impeller powered to rotate by a drive system and having a fluid passage between an impeller fluid inlet and a fluid outlet located radially of the fluid inlet; and a recoveiy by-pass turbine system comprising a recovery by-pass turbine mounted to rotate with the impeller, wherein the recoveiy turbine system diverts a portion of fluid that has exited the impeller fluid outlet back into the impeller fluid intake, wherein the remaining portion of fluid exits the pump through the pump outlet.

Abstract: A single wheel unit adapted to be mounted on a vehicle body (11) comprising: a wheel frame supporting a suspension mechanism (15) and a wheel assembly mounted on the suspension mechanism (15), and steering means mounted between the wheel frame and vehicle body (11) for pivoting the wheel frame relative to the vehicle body (11) so as to steer a vehicle, wherein the steering means includes two steering components (30) pivotally attached (32, 33) one at each of the leading and trailing portions of the wheel frame and capable of being actuated to independently displace the leading and trailing portions laterally of the vehicle body (11).