the number of internal lobes 48 is one greater than the number of external lobes 42 pump ring 34 is shown in fig2 with its lobes 42 of outer peripheral surface 40 engaged with various points along inner peripheral wall surface 46 of stator ring 36 to define a series of pressure chambers therebetween upon rotation of pump ring 34 about rotary axis u201c a u201d stator ring 36 is caused to rotate in pump chamber 30 about axis u201c b u201d at a reduced speed relative to the rotary speed of pump ring 34 such relative and eccentric rotation causes a progressive reduction in the volume of the pressure chambers thereby generating a pumping action such that fluid is drawn from the sump through an inlet tube 52 as best seen from fig1 inlet tube 52 communicates with an inlet port 54 formed in pump housing 26 which in turn supplies fluid to an inlet chamber 56 that communicates with pump chamber 30 the pumping action caused by rotation between pump ring 34 and stator ring 36 within pump chamber 30 causes the fluid to ultimately be discharged into an annular outlet chamber 58 formed in pump housing 26 at the higher outlet pressure fluid discharged from outlet chamber 58 is delivered to a central lubrication passage 60 formed in shaft 22 via a plurality of radial supply bores 62 central passage 60 communicates with various rotary elements located downstream of.