US Patent 7861503 Rotary cutting deck with hydraulic direct driven spindle

A rotary cutting deck with a hydraulic direct driven spindle includes a spindle housing attached to the rotary cutting deck and having a stepped internal bore, and a blade adapter inserted into the stepped internal bore and having a first, upper end connected to a hydraulic motor, and a second lower end with a contact surface against which a rotary cutting blade is clamped. A bolt threaded to the blade adapter provides the only clamping force between the rotary cutting blade and the contact surface, which is substantially flat and does not capture the blade. A notch or hole in the outer edge of the hydraulic direct driven spindle may be engaged to hold the hydraulic direct driven spindle stationary relative to the blade during installation or detachment of the blade.