The present invention relates to a turn system actuated by hydraulic cylinders, applied to the four wheels of sugar-cane harvesters, wherein the harvester (80) comprises a rear axle (23) and a front axle (24), with wheel assemblies (9) associated to the axles (23, 24), wherein the rear axle (23) and the front axle (24) have a turn system, the one of the rear axle (23) being actuated by means of a double-action rear hydraulic cylinder (1) and that of the front axle (24) being actuated by means of a double-action front hydraulic cylinder (11), the hydraulic cylinders (1, 11) receiving a flow of oil through at least one flow divider (61) connected to an ortibrol (65) actuated by means of a steering wheel (60) of the harvester (80), the flow of oil received by the flow divider (61) being proportional to a factor related to the turn of the steering wheel (60), the turn system enabling the turn of the wheel assemblies (9) in amplitude ranging from 0.5 to 40 degrees, to the right or to the left, with respect to the longitudinal axis of the harvester (80).

A rigid axle having an axle carrier, at each of the axial longitudinal end regions of which one wheel hub assembly is disposed, wherein: each wheel hub assembly has a rotatable wheel flange; the axle carrier is dropped in a drop region located between its longitudinal end regions; an electromechanical functional module having an electric energy converter machine is disposed in the drop region, which electric energy converter machine is connected to at least one wheel flange for transmitting a rotation, so that the energy converter machine can be used as at least one of the functional units stated hereinafter: i) as an electric drive unit for transmitting torque onto the at least one wheel flange, and ii) as an induction unit which can be operated as a generator for generating electric energy by transmitting torque from the at least one wheel flange to the energy converter machine; the axle carrier having a dropped tubular component which is continuous between its longitudinal end regions.

A rigid axle having an axle carrier, at each of the axial longitudinal end regions of which one wheel hub assembly is disposed, wherein: each wheel hub assembly has a rotatable wheel flange; the axle carrier is dropped in a drop region located between its longitudinal end regions; an electromechanical functional module having an electric energy converter machine is disposed in the drop region, which electric energy converter machine is connected to at least one wheel flange for transmitting a rotation, so that the energy converter machine can be used as at least one of the functional units stated hereinafter: i) as an electric drive unit for transmitting torque onto the at least one wheel flange, and ii) as an induction unit which can be operated as a generator for generating electric energy by transmitting torque from the at least one wheel flange to the energy converter machine; the axle carrier having a dropped tubular component which is continuous between its longitudinal end regions.