Patent ID: 7361000

Claim:
A pump unit for supplying oil to first and second hydraulic motors respectively connected to left and right drive wheels, comprising: a first hydraulic pump which includes a first pump shaft having a first end operatively connected to a power source and a second end opposite to the first end, the first hydraulic pump being fluidly connected to the first hydraulic motor through a first closed circuit; a second hydraulic pump which includes a second pump shaft having a first end operatively connected to the first pump shaft and a second end opposite to the first end, the second hydraulic pump being fluidly connected to the second hydraulic motor through a second closed circuit; a housing for accommodating the first and second hydraulic pumps; and a charge pump which is driven by the second end of the second pump shaft and which supplies pressure oil to both the first and second closed circuits, wherein the housing includes a partition wall that divides an inner space of the housing into a first pump accommodating chamber and a second pump accommodating chamber, and a first opening that has the first pump accommodating chamber opened in a direction along an axis line of the first pump shaft and that has a size for allowing the first hydraulic pump to be passed therethrough, and a second opening that has the second pump accommodating chamber opened in a direction along an axis line of the second pump shaft and that has a size for allowing the second hydraulic pump to be passed therethrough, and the first and second openings are respectively closed by a first center section forming parts of the first closed circuit and a second center section forming parts of the second closed circuit.