Work machine including hydrostatic ground drive which automatically provides increased propulsion torque when the mechanical transmission is in a high gear

摘要

A work machine having a mechanical transmission in combination with a hydrostatic ground drive including a primary drive and a secondary drive engageable for providing additional propulsion torque in a power assist mode, the hydrostatic drive automatically providing an increased torque capability when the transmission is engaged in a high speed range, thereby allowing the work machine to accelerate from a complete stop to a high speed range with the transmission in a high speed range without the need to stop to shift the mechanical transmission to accommodate an increased propulsion torque requirement.