A mud motor bearing assembly, comprising: a stationary housing including an inner wall surface defining an interior bore; a rotatable drive shaft extending through the interior bore of the stationary housing, the rotatable drive shaft being tubular and having a uniform outer diameter terminating at an outlet section with an enlarged outer diameter, the rotatable drive shaft including an inner bore for passage of a drilling fluid; a bearing section configured to bear both a radial load and an axial load, the bearing section including: at least a pair of stationary bearing rings, each of the stationary bearing rings having an inner periphery and an outer periphery, the outer periphery of each of the stationary bearing rings operatively engaged to the inner wall surface of the stationary housing, the inner periphery of each of the stationary bearing rings including a wedge-shaped projection; at least a pair of rotating bearing rings, each of the rotating bearing rings having an inner periphery and an outer periphery, the inner periphery of each of the rotating bearing rings operatively engaged to the rotatable drive shaft, the outer periphery of each of the rotating bearing rings including a wedge-shaped projection; wherein the pair of stationary bearing rings and the pair of rotating bearing rings are in a stacked arrangement, and wherein the wedge-shaped projections of the pair of stationary bearing rings form a wedge-shaped recess accommodating the wedge-shaped projection of one of the pair of rotating bearing rings in sliding engagement. a stationary housing including an inner wall surface defining an interior bore; a rotatable drive shaft extending through the interior bore of the stationary housing, the rotatable drive shaft being tubular and having a uniform outer diameter terminating at an outlet section with an enlarged outer diameter, the rotatable drive shaft including an inner bore for passage of a drilling fluid; a bearing section configured to bear both a radial load and an axial load, the bearing section including: at least a pair of stationary bearing rings, each of the stationary bearing rings having an inner periphery and an outer periphery, the outer periphery of each of the stationary bearing rings operatively engaged to the inner wall surface of the stationary housing, the inner periphery of each of the stationary bearing rings including a wedge-shaped projection; at least a pair of rotating bearing rings, each of the rotating bearing rings having an inner periphery and an outer periphery, the inner periphery of each of the rotating bearing rings operatively engaged to the rotatable drive shaft, the outer periphery of each of the rotating bearing rings including a wedge-shaped projection; wherein the pair of stationary bearing rings and the pair of rotating bearing rings are in a stacked arrangement, and wherein the wedge-shaped projections of the pair of stationary bearing rings form a wedge-shaped recess accommodating the wedge-shaped projection of one of the pair of rotating bearing rings in sliding engagement. at least a pair of stationary bearing rings, each of the stationary bearing rings having an inner periphery and an outer periphery, the outer periphery of each of the stationary bearing rings operatively engaged to the inner wall surface of the stationary housing, the inner periphery of each of the stationary bearing rings including a wedge-shaped projection; at least a pair of rotating bearing rings, each of the rotating bearing rings having an inner periphery and an outer periphery, the inner periphery of each of the rotating bearing rings operatively engaged to the rotatable drive shaft, the outer periphery of each of the rotating bearing rings including a wedge-shaped projection; wherein the pair of stationary bearing rings and the pair of rotating bearing rings are in a stacked arrangement, and wherein the wedge-shaped projections of the pair of stationary bearing rings form a wedge-shaped recess accommodating the wedge-shaped projection of one of the pair of rotating bearing rings in sliding engagement.