Hydraulic motor for vehicle wheel

An apparatus comprising a hydraulic motor for a vehicle wheel, said hydraulic motor comprising a hydrodynamic element, a reaction element, a front bearing, a rear bearing, a support, an oil distributor, and a brake, wherein said hydrodynamic element comprises cells, pistons mounted so as each to slide in a respective cell, thereby defining a variable-volume chamber therein, and ducts that lead into said cells in order to communicate with said chambers, wherein said reaction element comprises an annular cam on which an active face of each piston acts, wherein said front and rear bearings at least indirectly enable said reaction element and said hydrodynamic element to rotate with respect to each other about an axis of rotation, wherein said support is rotationally linked to one of said elements, said vehicle wheel being rotationally linked to the other of said elements when in use, wherein said oil distributor rotates as one with said reaction element and brings said ducts selectively into communication with an oil supply line and a return line depending on an angular position thereof relative to said hydrodynamic element, and wherein said brake is mounted functionally between said two elements in order to selectively prevent rotational movement, said brake having at least one first braking surface rotationally coupled to said hydrodynamic element, and a second braking surface rotationally coupled to said reaction element, wherein each piston is mounted radially with respect to the axis of rotation, and wherein said hydrodynamic element is secured to a collar that surrounds said oil distributor and that bears, on a radially outer face thereof, means for rotationally coupling to said at least one first braking surface, said brake thus being disposed around said distributor.