Gear pump or motor with low pressure bearing lubrication

An improved rotary gear apparatus, comprising:

• a housing having low pressure and high pressure chamber;
• a pair of shafts mounted for rotation in said housing on bearings supported by said housing;
• a pair of gears, one mounted on each of said shafts, said gears having teeth intermeshing at a zone between said low pressure chamber and said high pressure chamber, said teeth sequentially defining initially contracting and then expanding volumes therebetween as said gears intermesh in said zone;
• at least a pair of seal plates, at least one plate mounted on each side of said gears between said bearings and said gears with said shafts extending through bores in said seal plates;
• first channel means in each of said seal plates, said first channel means originating on the side of said seal plate facing said gears adjacent to said zone and opening into one of said bores, for receiving fluid only from a first adjacent one of said bearings on one side of said gears and for passing said fluid directly into an expanding one of said volumes;
• second channel means in each of said seal plates, said second channel means originating on the opposite side of said seal plate at said low pressure chamber, for passing fluid only to a second adjacent one of said bearings on the same side of said gears;
• and
• means for receiving fluid only from said second adjacent bearing and passing said fluid only into said first adjacent bearing.