Patent ID: 9228586
Filing Date: 2016-01-05
CPC Classification: F04C

Claim Text:
1. A pump comprising: a casing defining an interior volume; a first gear disposed within the interior volume, the first gear having a first gear body and a plurality of first gear teeth; a second gear disposed within the interior volume, the second gear having a second gear body and a plurality of second gear teeth projecting radially outwardly from the second gear body, the second gear is disposed such that a second face of at least one tooth of the plurality of second gear teeth aligns with a first face of at least one tooth of the plurality of first gear teeth; a first variable-speed motor that rotates the first gear about a first axial centerline of the first gear in a first direction to transfer hydraulic fluid from an inlet of the pump to an outlet of the pump along a first flow path; and a second variable-speed motor that rotates the second gear, independently of the first motor, about a second axial centerline of the second gear in a second direction to contact the second face with the first face and to transfer the hydraulic fluid from the inlet of the pump to the outlet of the pump along a second flow path, the contact sealing a fluid path from the outlet of the pump to the inlet of the pump such that a slip coefficient is at least one of 5% or less for a pump pressure in a range of 3000 psi to 5000 psi, 3% or less for a pump pressure in a range of 2000 psi to 3000 psi, 2% or less for a pump pressure in a range of 1000 psi to 2000 psi and 1% or less for a pump pressure in a range up to 1000 psi.