Rotary machine of the deformable rhombus type comprising an improved transmission mechanism

A rotary machine with a deformable rhomb comprising

• a) a rotor (3) which is a deformable rhomb (4) in contact, with or without clearance, with the internal surface of a housing (1) forming a stator (2) and/or with the external surface of a central crown, the said deformable rhomb (4) comprising four pistons (6) connected one following the other by a pivotal hinge (7) with an axis parallel to the longitudinal axis of the housing (1) and thus forming a closed chain;
• and also
• b) a transmission mechanism (14) of the movement between the pistons (6) and a rotation shaft (15) coaxial to the central axis of the machine,
• the said machine being characterized in that the said transmission mechanism (14) comprises:
• a first rolling body (16) mounted fixedly on at least one piston (6), preferably on each piston (6), the axis (17) of the said first rolling body (16) passing in the centre of the piston (6) and connected to
• a second rolling body (19), the centre of which passes through the central axis of the machine and is integral with the said rotation shaft (15),
• the first rolling body (16) being connected to the second rolling body (19) directly or by an intermediate transmission member (18)
• and that the demultiplication ratio between the first (16) and the second rolling body (19) is equal to 2 and is positive.