Abstract: In an axial-piston engine of the type known as a "wabbler" engine, in which the motion of the pistons is transferred to a straight main shaft by means of a non-rotating element (referred to as the "wabbler") which nutates as the shaft rotates and transfers the motion to the pistons via arms at its periphery, a design of the wabbler in which the wabbler is made in two or more parts so as to enclose a swashplate on the shaft, with thrust bearings between the wabbler and the swashplate (which latter is fixed to the shaft). The parts of the wabbler are rigidly connected together, so as to maximise the bending strength of the assembly in resisting the thrust loads from the pistons, and to facilitate the transfer of the loads to the bearing surfaces so as to avoid excessive localized loading of the bearings.