High efficiency fixed displacement vane pump

A pump assembly comprising:

• a drive shaft;
• a first gear connected to the drive shaft;
• a second gear intermeshed with the first gear;
• a pump input shaft connected to the second gear;
• and
• a pump comprising:
• a body concentric with a first axis, the body defining a pump chamber having a first open end and an inlet that receives the fluid;
• a first plate sealingly connected to the body disposed over the first open end, the first plate having an outlet that communicates with the pump chamber;
• a rotor rotatably supported about a second axis within the pump chamber and connected to the pump input shaft, wherein the second axis is offset from and parallel to the first axis, the rotor having a first open ended cylindrical portion in contact with a second open ended cylindrical portion to define a central chamber, and wherein the rotor includes a plurality of radially and axially extending slots disposed through the first cylindrical portion and the second cylindrical portion;
• a plurality of vanes radially slidably disposed within the plurality of slots, the plurality of vanes each having an inner end and an outer end;
• and
• a ring disposed around the pump input shaft within the central chamber radially inward of the plurality of vanes, wherein the ring is configured to limit the radial inward movement of the plurality of vanes, and
• wherein the drive shaft drives the first gear, the first gear drives the second gear, and the second gear drives the pump input shaft to drive the rotor.

A pump assembly comprising:

• a drive shaft;
• a first sprocket connected to the drive shaft;
• a second sprocket;
• a chain connected to the first sprocket and the second sprocket
• a pump input shaft connected to the second sprocket;
• and
• a pump comprising:
• a body concentric with a first axis, the body defining a pump chamber having a first open end and an inlet that receives the fluid;
• a first plate sealingly connected to the body disposed over the first open end, the first plate having an outlet that communicates with the pump chamber;
• a rotor rotatably supported about a second axis within the pump chamber and connected to the pump input shaft, wherein the second axis is offset from and parallel to the first axis, the rotor having a first open ended cylindrical portion in contact with a second open ended cylindrical portion to define a central chamber, wherein the rotor includes a plurality of radially and axially extending slots disposed through the first cylindrical portion and the second cylindrical portion and wherein the first cylindrical portion includes a first feature and the second cylindrical portion includes a second feature that interact to radially and axially align the first and second cylindrical portions relative to one another;
• a plurality of vanes radially slidably disposed within the plurality of slots, the plurality of vanes each having an inner end and an outer end;
• and
• a ring disposed within the central chamber radially inward of the plurality of vanes, wherein the ring is configured to limit the radial inward movement of the plurality of vanes, and
• wherein the drive shaft drives the first sprocket, the first sprocket drives the second sprocket via the chain, and the second sprocket drives the pump input shaft to drive the rotor.