Abstract

A motor drive assembly for selective rail or track operation of an excavators or other mobile platform via a source of hydraulic pressure. The motor drive assembly may include one or more drive arm assemblies mounted at ends of the mobile platform underbody, with the drive arm assembly including a motor, a gearbox, and hydraulic features for operation, including a counterbalance valve assembly, as well as improved gearbox and coupler elements operable therewith. The counterbalance valve assembly may include a cross-port relief valve and may have a first hydraulic operating circuit and a second hydraulic operating circuit. The first hydraulic operating circuit may communicate hydraulic pressure to the gearbox to enable movement of the mobile platform, and the second hydraulic operating circuit may prevent undesired communication of hydraulic pressure to the gearbox.

IPC Classes  ?

• B60K 17/10 - Arrangement or mounting of transmissions in vehicles characterised by arrangement, location or kind of gearing of fluid gearing
• B61D 15/00 - Other railway vehicles, e.g. scaffold carsAdaptations of vehicles for use on railways
• B62D 55/04 - Endless-track vehicles with tracks and alternative ground wheels, e.g. changeable from endless-track vehicle into wheeled vehicle and vice versa
• E02F 9/02 - Travelling gear
• B61K 5/02 - Devices secured to the vehiclesTurntables integral with the vehicles
• F16H 47/04 - Combinations of mechanical gearing with fluid clutches or fluid gearing the fluid gearing being of the volumetric type the mechanical gearing being of the type with members having orbital motion
• B61C 9/00 - Locomotives or motor railcars characterised by the type of transmission system usedTransmission systems specially adapted for locomotives or motor railcars