Patent ID: 9551222
Date: 2017-01-24
CPC Classifications: F01C,F03C,F04C,F16D

Claim:
1. A hydraulic drive comprising: a stationary housing defining a shaft passage; a main drive shaft having a first end and a second end, the main drive shaft being rotatable within the stationary housing, the main drive shaft extending through the shaft passage of the stationary housing, the main drive shaft being coupled to an inner gear by a splined connection located adjacent the second end; a valve drive shaft having a torque transmitting connection with the main drive shaft by the inner gear located adjacent the second end of the main drive shaft; a hydraulic motor for rotating the valve drive shaft, the valve drive shaft transferring torque to the main drive shaft such that the main drive shaft rotates relative to the stationary housing, the hydraulic motor including a motor housing assembly that is mounted to the stationary housing; a driven hub mounted over the stationary housing, the driven hub including a plurality of openings for receiving fasteners used to mount the driven hub to a rotatable wheel; a sealing arrangement disposed between the stationary housing and the driven hub; a coupling/decoupling arrangement mounted over the first end of the main drive shaft, the coupling/decoupling arrangement allowing the hydraulic drive to be operated in an engaged mode where the main drive shaft is coupled to the driven hub in a direct drive arrangement and a disengaged mode where the main drive shaft is decoupled from the driven hub, wherein when the hydraulic drive is operated in the engaged mode, torque from the main drive shaft is transferred to the driven hub causing the driven hub to rotate relative to the stationary housing, and wherein when the hydraulic drive is operated in the disengaged mode, the driven hub can free wheel relative to the main drive shaft; a central fastener being aligned along an axis of rotation that extends through the shaft passage, an end of the central fastener engaging a plug secured within the coupling/decoupling arrangement, the central fastener being rotatable in a first direction to cause the central fastener to move axially outwardly such that the plug and the coupling/decoupling arrangement move from the engaged mode to the disengaged mode, and the central fastener being rotatable in the opposite, second direction to push the plug and the coupling/decoupling arrangement from the disengaged mode to the engaged mode; a bearing positioned between the driven hub and the stationary housing for allowing the driven hub to rotate relative to the stationary housing about the axis of rotation that extends through the shaft passage; a brake including a brake pack having first brake pads mounted to the stationary housing and second brake pads carried by the driven hub, the first and second brake pads being interleaved relative to one another; a piston engaged with and carried with the coupling/decoupling arrangement and the driven hub, the piston rotating when the coupling/decoupling arrangement and the driven hub are rotated about the axis of rotation by the main drive shaft; and a spring for actuating the brake by applying a braking force through the piston to the brake pack to compress the first and second brake pads together such that relative rotation between the driven hub and the stationary housing is resisted by friction between the first and second brake pads, and wherein the brake is released by applying a brake release hydraulic pressure to the piston to generate a brake release force that opposes the braking force.