Patent ID: 6926604

Claim:
A crop harvesting machine, comprising: a driven crop supply device operable for feeding harvested crop; a driven crop processing device located for receiving crop fed by said crop supply device; an internal combustion engine having an output shaft; a hydrostatic transmission including a variable displacement pump hydraulically coupled to a motor; said motor being coupled for driving said supply device; said pump having an electrically responsive displacement control arrangement and being coupled for being driven by said output shaft; said output shaft being coupled for driving said crop processing device; an electrical control unit for establishing a desired relationship between the speed of said supply device and the speed of said processing device; said displacement control arrangement being coupled to said control unit for receiving a displacement control signal for effecting a change in pump displacement; a speed sensor arrangement located for sensing the speed of at least one of said internal combustion engine output shaft and processing device and being coupled for transmitting an electrical signal representative of the sensed speed to said control unit; said electrical control unit being preprogrammed with a desired speed relationship between the respective speeds of said crop processing device and said supply device; and said control unit being responsive to said electrical signal and to said desired speed relationship for generating a control output signal that brings about a change in the rotational speed of said supply device such that the difference between the actual rotational speed ratio of the supply device and crop processing device and the desired rotational speed ratio is at least reduced.