Patent ID: 8235691
Filing Date: 2012-08-07
Classification: F04C,Y10T

Abstract:
1. An external gear pump, comprising: a primary shaft as a drive shaft having a generally cylindrical body and including a drive member; a secondary shaft as an idler shaft adjacent the primary shaft; a drive gear and an idler gear, the drive gear slip fitted on and rotatably linked about the primary shaft and being one of a first gear and a second gear, the idler gear being the other one of the first gear and the second gear and being slip fitted on the secondary shaft, the second gear having a larger outer diameter and outer circumference than the first gear, the first and the second gear both having like-sized interior cylindrical walls defining channels having a circumference slightly larger than a circumference of the primary shaft and both having a linking member associated with the drive member to link the drive gear with the primary shaft, the first and second gears being interchangeable as the drive gear on the primary shaft to deliver different flow displacement for one rotation of the primary shaft; and a pump housing receiving the primary shaft and enclosing the first gear, the second gear, and the secondary shaft within the pump housing, the pump housing including a first endplate, a second endplate, and a gear case there between, the gear case having a first bored wall defining a first bore sized to accommodate the first gear, and a second bored wall defining a second bore larger than the first bore and sized to accommodate the second gear, the gear case attached to the first and second endplates with the first bored wall fitting about the first gear and the second bored wall fitting about the second gear regardless of which of the first gear and the second gear is the drive gear rotatably linked about the primary shaft.