Harvester threshing rotor drive having variable speed belt drive and clutching means

In a combine harvester having a wheeled frame supporting an engine, an operator's station, a crop processor with a rotor for threshing crop material, a crop header and a conveyor means for moving crop material from the header to the threshing rotor, the combination comprising:

• a threshing rotor shaft, and
• a drive train connecting said engine in driving relation to said rotor shaft, including
• a first belt pulley on one end of said rotor shaft,
• a variable speed belt drive, including
• first and second variable pitch sheaves, each with a pair of sheave halves, one of which is axially shiftable relative to the other to change the effective diameter of said sheaves between predetermined large and small diameter conditions, the shiftable sheave half of one of said sheaves being spring biased axially toward its large diameter condition,
• an actuator operable to axially move the shiftable half of the other sheave between its small diameter condition and its large diameter condition, and
• a V-belt operatively engaging said variable pitch sheaves, said one sheave changing from a large diameter condition to a small diameter condition when said actuator changes said other sheave from its small diameter condition to its large diameter condition, the speed ratio of said variable speed belt drive being changeable only when it is running,
• a second belt pulley secured to one of sid sheaves to rotate concentrically therewith and said otherbsheave being driven by said engine,
• a drive belt operatively engaging said first and second belt pulleys,
• an idler clutch pulley engaging said drive belt and being shiftable between a first position, in which said drive belt is not tensioned, and a second position in which said belt is tensioned to provide driving torque to said rotor,
• motion transmitting means connected to said clutch pulley for moving the latter between its first and second positions including a manually operable control at said operator's station for selectively operating said motion transmitting means, and
• control means for said actuator including a manually operable control at said operator's station for actuating said actuator, whereby said rotor may be disconnected from said variable speed belt drive to permit the latter to be driven by said engine and its speed ratio changed to effect a higher output torque.