An oil disc brake, comprising: - a box-like frame, which defines internally a receptacle; - a shaft, which is supported so that it can rotate about its own axis by said box-like frame; - a supporting element, which is arranged around said shaft and is jointly connected to said shaft in rotation about its axis; - braking discs which are arranged coaxially to said shaft and are associated with said supporting element, said braking discs being jointly connected to said shaft in rotation about its own axis; - complementary braking discs (7a, 7b, 7c), which alternate with said braking discs along said shaft and are associated with said box-like frame, said complementary discs (7a, 7b, 7c) being movable with respect to said box-like frame and with respect to said shaft exclusively parallel to the axis of said shaft; - braking means, which act on command on said discs and on said complementary discs (7a, 7b, 7c) for their packing along a direction which is parallel to the axis of said shaft between two mutually opposite axial abutments (9, 10); and - means for collecting a lubricating liquid which is arranged in said receptacle and means for distributing said lubricating liquid in a centrifugal radial direction on said discs and said complementary discs (7a, 7b, 7c); the disc brake being characterized in that it comprises confinement means comprised of two complementary end discs (7a, 7c) which are arranged at the axial ends of the set of complementary discs (7a, 7b, 7c), which delimit, in said receptacle and in cooperation with said box-like frame, a compartment which contains said discs and said complementary discs (7a, 7b, 7c), said compartment being connected to the remaining part of said receptacle through passages for controlled seepage, the disc brake further comprising at least one passage for the return of said lubricating liquid, which connects said compartment to the remaining part of said receptacle, the mouth of said at least one return passage in said compartment being arranged above the free surface of the lubricating liquid in said receptacle. - a box-like frame, which defines internally a receptacle; - a shaft, which is supported so that it can rotate about its own axis by said box-like frame; - a supporting element, which is arranged around said shaft and is jointly connected to said shaft in rotation about its axis; - braking discs which are arranged coaxially to said shaft and are associated with said supporting element, said braking discs being jointly connected to said shaft in rotation about its own axis; - complementary braking discs (7a, 7b, 7c), which alternate with said braking discs along said shaft and are associated with said box-like frame, said complementary discs (7a, 7b, 7c) being movable with respect to said box-like frame and with respect to said shaft exclusively parallel to the axis of said shaft; - braking means, which act on command on said discs and on said complementary discs (7a, 7b, 7c) for their packing along a direction which is parallel to the axis of said shaft between two mutually opposite axial abutments (9, 10); and - means for collecting a lubricating liquid which is arranged in said receptacle and means for distributing said lubricating liquid in a centrifugal radial direction on said discs and said complementary discs (7a, 7b, 7c);