DUAL CLUTCH TYPE POWER TRANSMISSION WITH ALTERNATIVE TORQUE TRANSMISSION PATH PROVIDING ALTERNATIVE RATIOS

摘要

A dual clutch type transmission has first and second sections which respectively include first and second clutches. The clutches may be operated to allow torque transfer from an input to an output by way of the first section or the second section. One or more additional gear ratios is provided by a torque transfer pathway connecting the first and second sections such that torque is delivered from the input to the output by way of one or more stages of the first section and one or more stages of the second section. The additional gear ratios may comprise extra low gear ratios. Some embodiments provide transmissions suitable for driving pumps for use in hydraulic fracturing of geological formations.