Patent ID: 7028472

Claim:
A pump unit for operation in association with first and second hydraulic motors that respectively drive first and second driving wheels comprising: a first hydraulic pump and a second hydraulic pump respectively connected to said first and second hydraulic motors, which are apart from said first and second hydraulic pumps, via a first pair of hydraulic lines and a second pair of hydraulic lines; a center section supporting said first hydraulic pump and said second hydraulic pump; a housing accommodating said first hydraulic pump and said second hydraulic pump, said first hydraulic pump, said second hydraulic pump, said first pair of hydraulic lines, said second pair of hydraulic lines, said center section and said housing being integrally connected together to constitute a single unit; and a reservoir tank, which is separated from said single unit by a clearance, for storing hydraulic fluid to be replenished to said first pair of hydraulic lines and said second pair of hydraulic lines; wherein said reservoir tank is fluidly communicated with an internal space of said housing via a first conduit extending through said clearance and forming a fluid communication passage, and is also fluidly communicated with an inlet port for charging to said first pair of hydraulic lines and said pair of hydraulic lines via a second conduit extending through said clearance and forming a hydraulic fluid replenishing passage.