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A dual tandem pump apparatus having a pair of coaxially arranged pump shafts and a separate input shaft that is not coaxial with the pump shafts. The trunnion arms for the two pumps may be mounted in different locations to increase application flexibility. Charge pumps may be mounted on end caps sec

A dual tandem pump apparatus having a pair of coaxially arranged pump shafts and a separate input shaft that is not coaxial with the pump shafts. The trunnion arms for the two pumps may be mounted in different locations to increase application flexibility. Charge pumps may be mounted on end caps secured to the housing or may be driven directly by the input shaft. A coupler or bevel gear arrangement is used inside the pump housing to drive the pump shafts from the input shaft.

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What is claimed is: 1. A pump apparatus comprising: a pump housing having a first pump chamber formed therein and having a first opening extending in a first direction, a second pump chamber formed therein and having a second opening extending in a second direction, and a gear chamber formed therei

What is claimed is: 1. A pump apparatus comprising: a pump housing having a first pump chamber formed therein and having a first opening extending in a first direction, a second pump chamber formed therein and having a second opening extending in a second direction, and a gear chamber formed therein and having a third opening extending in a third direction perpendicular to the first and second directions; a plurality of gears located in the gear chamber, wherein the third opening is larger than one of the gears; a first pump and a first swash plate engaged thereto disposed in the first pump chamber, and a first trunnion arm engaged to the first swash plate and extending out of the pump housing; a second pump and a second swash plate engaged thereto disposed in the second pump chamber, and a second trunnion arm engaged to the second swash plate and extending out of the pump housing; a first pump shaft drivingly engaged to the first pump and a second pump shaft drivingly engaged to the second pump; and an input shaft disposed in the pump housing and drivingly engaged to both the first and second pump shafts, where at least one end of the input shaft extends out of the pump housing and the longitudinal axis of the input shaft is perpendicular to the longitudinal axes of the first and second pump shafts, wherein the first and second trunnion arms are mounted parallel to one another and perpendicular to the longitudinal axis of the input shaft. 2. A pump apparatus as set forth in claim 1, wherein the longitudinal axes of the first and second pump shafts are collinear. 3. A pump apparatus as set forth in claim 1, wherein the first and second trunnion arms both extend out of the same side of the pump housing. 4. A pump apparatus as set forth in claim 1, wherein the first trunnion arm extends out of a first side of the pump housing and the second trunnion arm extends out of a second side opposite to the first side of the pump housing. 5. A pump apparatus as set forth in claim 1, wherein both ends of the input shaft extend out of the pump housing. 6. A pump apparatus as set forth in claim 1, further comprising a first end cap mounted to the pump housing adjacent to the first pump chamber and having a first set of system ports formed therein, and a second end cap mounted to the pump housing adjacent the second pump chamber and having a second set of system ports formed therein, where the first and second sets of system ports extend into their respective end cap in a direction parallel to the longitudinal axis of the input shaft. 7. A pump apparatus comprising: a pump housing having first and second pump chambers formed therein; a first end cap mounted to the pump housing adjacent to the first pump chamber and a second end cap mounted to the pump housing adjacent the second pump chamber, both end caps comprising a first surface mounted to the pump housing, a second surface formed generally parallel to the first surface, and a plurality of sides connecting the first and second surfaces; a first pump rotatably disposed on the first end cap and a second pump rotatably disposed on the second end cap; a first pump shaft drivingly engaged to the first pump and a second pump shaft drivingly engaged to the second pump; an input shaft disposed in the pump housing and drivingly engaged to both the first and second pump shaft, where at least one end of the input shaft extends out of the pump housing and the longitudinal axis of the input shaft is perpendicular to the longitudinal axes of the first and second pump shafts; a first charge pump mounted on the second surface of the first end cap; and a first set of system ports formed in the first end cap, where the first set of system ports extend into one of the sides of the first end cap in a direction parallel to the longitudinal axis of the input shaft. 8. A pump apparatus as set forth in claim 7, further comprising a second set of system ports formed in the second end cap, where the second set of system ports extend into one of the sides of the second end cap in a direction parallel to the longitudinal axis of the input shaft. 9. A pump apparatus as set forth in claim 7, further comprising a mounting flange formed on the pump housing adjacent to the first set of system ports. 10. A pump apparatus as set forth in claim 8, wherein the longitudinal axes of the first and second pump shafts are collinear. 11. A pump apparatus as set forth in claim 8, wherein both ends of the input shaft extend out of the pump housing. 12. A pump apparatus comprising: a pump housing having a first pump chamber formed therein and having a first opening extending in a first direction, a second pump chamber formed therein and having a second opening extending in a second direction, and a gear chamber formed therein and having a third opening extending in a third direction perpendicular to the first and second directions; a plurality of gears located in the gear chamber, wherein the third opening is larger than one of the gears; a first end cap mounted to the pump housing adjacent to the first pump chamber and a second end cap mounted to the pump housing adjacent to the second pump chamber; a first pump rotatably disposed on the first end cap and a second pump rotatably disposed on the second end cap; a first pump shaft drivingly engaged to the first pump and a second pump shaft drivingly engaged to the second pump; an input shaft disposed in the pump housing and drivingly engaged to both the first and second pump shafts, where at least one end of the input shaft extends out of the pump housing and the longitudinal axis of the input shaft is perpendicular to the longitudinal axes of the first and second pump shafts; and a first set of system ports formed in the first end cap, where the first set of system ports extend into the first end cap in a direction perpendicular to the longitudinal axis of the input shaft. 13. A pump apparatus as set forth in claim 12, further comprising a second set of system ports formed in the second end cap, where the second set of system ports extend into the second end cap in a direction perpendicular to the longitudinal axis of the input shaft. 14. A pump apparatus as set forth in claim 13, wherein the longitudinal axes of the first and second pump shafts are collinear. 15. A pump apparatus as set forth in claim 13, wherein both ends of the input shaft extend out of the pump housing. 16. A pump apparatus as set forth in claim 12, wherein the pump housing further comprises a first wall located between the first pump chamber and the gear chamber, and a second wall located between the second chamber pump and the chamber.