Patent ID: 7497082
Filing Date: 2009-03-03
Classification: B60K,F16H

Abstract:
1. A center section for use in connection with a hydraulic drive apparatus having a housing and a sump, the center section comprising: a first member having a first hydraulic porting system formed therein, the first member further comprising: a first running surface for a first cylinder block; a first bottom surface formed generally opposite the first running surface and having a plurality of first extensions protruding therefrom, each first extension having a passage open to the first hydraulic porting system; and a first mounting flange having a plurality of first openings formed therein for connection to the first hydraulic porting system; a second member separably connected to the first member and having a second hydraulic porting system formed therein, the second member further comprising: a second running surface for a second cylinder block; a second mounting flange having a plurality of second openings formed therein for connection to the second hydraulic porting system, wherein the second openings are shaped to receive the first extensions of the first member to connect the first and second hydraulic porting systems to form a closed hydraulic circuit; and a plurality of check valves mounted in the first openings in the first mounting flange to selectively connect the closed hydraulic circuit to the sump.