Abstract: A disclosed mud motor includes a rotor head, a motor block, a hollow rotor, an inlet shaft, and an outlet shaft. In the operation of one embodiment, a pressurized drilling mud enters the rotor head through the inlet shaft. Some or all of the drilling mud is directed through an included inlet passage onto pistons which are included in the motor block and disposed concentrically around the outlet shaft. A downward action of the pistons resulting from the drilling mud causes an included power plate to rotate. Rotation of the power plate causes the hollow rotor and the rotor head to also rotate. The hollow rotor may be attached to a drilling implement. Rotation of the power plate also causes some or all of the drilling mud directed onto the pistons to be discharged into the outlet shaft through an included discharge passage. During the operation of one embodiment of the mud motor, the pistons do not rotate around the outlet shaft, but instead remain substantially in their original concentric alignment.