1,107,494. Rotary fluid-pumps and motors. TRW Inc. June 28, 1966, No. 29044/66. Heading F1F. In a rotary fluid-pump or motor of the n and n + 1 lobe type, a pair of internally-meshing gears 81, 83 couple a rotary valve-member 54, which is attached to a driving or power-output shaft 52, to an externally-lobed, or toothed, rotor 42 and also serve to control the planetary motion of the rotor relative to an internally-lobed, or toothed, stator 40 that meshes therewith, the valve-member being provided to control the flow of fluid between a plurality of working chambers (A to G), Fig. 2 (not shown), which are situated between the stator and the rotor, and annular fluid inlet and outlet passages 29, 30 by way of a corresponding plurality of passages, or so-called ports, (44 to 50), Fig. 3 (not shown), that are formed in a housing member 22 and fixed annular plates 37, 38. The valvemember includes an axially-orientated bore 59, which is constantly in communication with the inlet passage 29, a plurality of radially-orientated passages (62 to 69), and a plurality of axiallyorientated slots (72 to 79) that are continuously in register with the outlet passage 30 and disposed alternately with respect to the passages (62 to 69), the passages (62 to 69) and the slots (72 to 79) being situated such that when the pump or motor is operating they are periodically and sequentially brought into register with the adjacent ends of the passages (44 to 50). The shaft 52 and the valvemember are connected to each other by a pin 57, the valve-member being constituted by co-axial tubular-bodies 55, 56 that are joined together by screw-threads 58. The gear 83 is coupled to the valve-member by a tongue or tangs 82 on the gear engaging with slots in the end of said member. A stub shaft 84 on the gear 83 is fixed to the rotor 42 so as to be rotatable therewith. In a second embodiment, Figs. 5 to 8 (not shown) a driving or power-output shaft (138) is connected to the pumping rotor (144) by internally-meshing gears (140, 146), and the rotor is coupled to a rotary valve-member (149) by an axially-orientated pin (168), the valve-member being provided with an axially-orientated bore (150) that is permanently in communication with a fluid-inlet passage (151) and a semi-annular channel (148) in the outer surface of the valve-member, which channel is in a transverse plane passing through a further semiannular channel (156) in the said surface and the ends of a plurality of passages (158 to 164) communicating with the working chambers (A to G). The channel (156) is continuously in communication with a fluid-outlet passage (157). In operation, the channel (148) connects the chambers on one side of the rotor to the inlet passage (151) while the other channel (156) connects the chambers on the other side of the rotor to the outlet passage (156). The pump or motor may be modified so that the rotor is fixed and the stator is rotatable in a planetary manner.