Abstract: Systems and methods for drilling a borehole are provided. One system includes a continuously variable transmission. An input shaft of the continuously variable transmission is coupled to a power supply. An output shaft of the continuously variable transmission is coupled to one or more system components such that the continuously variable transmission controls rotation of the one or more system components. One method for drilling a borehole includes supplying power to an input shaft of a continuously variable transmission. The method also includes controlling rotation of one or more system components using the continuously variable transmission during drilling of the borehole. The one or more system components are coupled to an output shaft of the continuously variable transmission. Also provided is a borehole that is drilled by this method.

Abstract: Systems and methods for directionally drilling a borehole are provided. One system includes a biasing subsystem that is configured to control a tendency of a bottom hole assembly during drilling of the borehole. The system also includes a continuously variable transmission. An output shaft of the continuously variable transmission is coupled to the biasing subsystem such that the continuously variable transmission is configured to control relative rotation of one or more components of the biasing subsystem during the drilling. One method includes controlling a tendency of a bottom hole assembly during drilling of the borehole using a biasing subsystem. The method also includes controlling relative rotation of one or more components of the biasing subsystem using a continuously variable transmission during the drilling. The one or more components are coupled to an output shaft of the continuously variable transmission.