The mechanism such as a motor or a pump comprises a cam (10) and a
cylinder block (12) which has a plurality of cylinders (14A, 14B, 14)
connected to communication orifices (34A, 35A; 34B, 35B) disposed in a
communication face (18). The mechanism further comprises a fluid
distributor (20) having a distribution face (22) which is provided with
distribution orifices (31A-31F, 32A-32F) suitable for being connected to
the feed or to the discharge. The communication orifices and the
distribution orifices communicate with one another as the cylinder block
and the distributor rotate relative to each other. At least certain
cylinders (14A, 14B) are connected to at least two communication orifices
(34A, 35A; 34B; 35B) spaced apart angularly (.alpha.) so that they
communicate simultaneously with respective distribution orifices
connected to the feed or to the discharge.