cover 18 into a tighter sealing contact with the gear housing 16 and front cover 14 the external axial area of the pump on which the pressurized fluid acts is equal to the cavity cross sectional area less the cross sectional area enclosed by the o ring seal 64 the internal axial area on which the high pressure fluid acts is at most equal to the axial area of the gear teeth between the roots and tips of the gears thus the internal axial area is substantially less than the external axial area with the result that the pump components are clamped together by the force of the pumped fluid acting on the external axial area of the rear cover 18 such force of course increases as the pump output pressure increases this clamping force makes it possible to eliminate any clamping bolts or clamping fasteners for the pump the pump 10 is driven by a suitable drive motor 80 which is mounted to the valve block 74 the drive motor 80 has a motor drive shaft 82 with an axial blind bore 84 having a hexagonal cross section which mates with the hexagonal drive connection 44 at the end of shaft 20 of the pump 10 motor 80 may be any suitable type of motor such as electric pneumatic or other rotational drive force fig6 illustrates in schematic form one of many possible applications for the hydraulic pump of the present invention in this application hydraulic fluid is supplied from an oil reservoir 86 to the valve block 74 via a line 88 where it is drawn into the inlet of pump 10 and pumped under pressure to a hydraulic cylinder 90 via a line 92 fluid may be exhausted to the oil reservoir.