Patent ID: 7398853
Filing Date: 2008-07-15
Classification: B60T,F16D,F16H,Y10T

Abstract:
1. A frame structure of a vehicle comprising a flywheel housing, an intermediate housing and a transmission case that are connected to each other along a longitudinal axis of the vehicle to constitute a vehicle frame with an inner space, and to accommodate a running-power transmission mechanism including a speed change unit for changing a speed of a rotational power from an engine via a forward/rearward movement switching unit and a PTO transmission mechanism including a PTO clutch for selectively performing power-transmission or power-shutoff of a rotational power from the engine via the forward/rearward movement switching unit, said flywheel housing having a first abutting surface and a second abutting surface respectively located closer to a first end and a second end of said flywheel housing along the longitudinal axis of the vehicle, said first abutting surface including a first opening that is sized to allow a flywheel to pass therethrough, said second abutting surface including a second opening that is sized to allow a forward/rearward movement switching unit to pass therethrough, said intermediate housing having a hollow body portion that extends along the longitudinal axis of the vehicle and a flange portion that is located at a first end of said hollow body portion, said flange portion having an abutting surface against which said second end of the flywheel housing abuts, a support surface that is located radially inwardly of said abutting surface so as to support said forward/rearward movement switching unit, and a first-end opening that is surrounded by said support surface and is closed by said forward/rearward movement switching unit, and said forward/rearward movement switching unit including a reverser unit for switching the power transmission direction from a drive shaft extending along the vehicle longitudinal axis to a driven shaft located parallel to the drive shaft, and a reverser housing for accommodating said reverser unit and supporting said drive shaft and said driven shaft, said frame structure being characterized in that: said speed change unit and said PTO clutch are accommodated in said transmission case; at least a portion of said forward/rearward movement switching unit is positioned within said flywheel housing by connecting said second abutting surface of said flywheel housing to said abutting surface of said intermediate housing in a state with said forward/rearward movement switching unit supported on said support surface of said intermediate housing; said hollow body portion of said intermediate housing accommodates transmission shafts including a propeller shaft that transmits the rotational power toward said speed change unit from said driven shaft and a main shaft that transmits the rotational power toward said PTO clutch from said drive shaft, in a state that no transmission units are supported on said transmission shafts within said intermediate housing; and said flange portion has an upper extension extending from a top wall of said hollow body portion towards an upper side of said hollow body portion, a lateral extension extending from a lateral wall of said hollow body portion towards a radially outer side and inner side of said hollow body portion and a lower extension extending from a bottom wall of said hollow body portion towards the upper side of said hollow body portion so as to define said abutting surface, said supporting surface and said first-end opening, thereby connecting said flywheel housing and said intermediate housing to each other in a state in which a center axis position of said hollow body portion is displaced vertically downward from a center axis position of said flywheel housing.