A radial cylinder hydraulic motor comprises: oscillating hydraulic cylinders (1) driven to oscillate by means of an eccentric crankpin (2) formed on the motor shaft (3), the oscillating cylinder liners (4) being provided with trunnions (5) for oscillation about a parallel axis (C) to the axis (A) of rotation of the motor shaft which are coupled oscillably to the motor crankcase (6); reciprocating pistons (7) within said liners which are provided with a runner (8) for sliding over the outer surface (9) of said eccentric crankpin; and a rotary disk distributor (10, 23) coupled to the motor shaft for synchronized rotation therewith, adapted to place the conduits (12, 13) of the hydraulic circuit in fluid communication with the conduits (14) of the respective cylinders during the delivery and discharge strokes via ports of slanted or through-going configuration; and advantageously includes the rotating disk of the distributor formed with a connection/supply means (38, 40) to the passageway between one face (27) and the inner wall of the distributor cover (41) incorporating a seal (28), with pressurized fluid in the area outside the seal. In another embodiment, it has the trunnions (5) formed with trough-like channels (30) in their outer surface (31), at the area of rubbing contact with the trunnion journals, into a branched layout (30) having a roughly trapezoidal projected shape, the channels in the branched layout being supplied pressurized fluid through one or more supply channels (32) from within the cylinder.