CPC E02F 9/2296 (2013.01) [E02F 9/225 (2013.01); E02F 9/2235 (2013.01); E02F 9/2253 (2013.01); F16H 61/421 (2013.01); F16H 61/47 (2013.01)] | 21 Claims |
1. A power machine having a frame, a power source supported by the frame, and a power conversion system including a hydraulic drive system operably coupled to the power source and configured to power at least one tractive element, the hydraulic drive system comprising:
a hydraulic circuit that includes a hydraulic pump in hydraulic communication with a hydraulic motor, the hydraulic motor being configured to operate with infinitely variable displacement to drive the power machine; and
a control device that is configured to:
determine a control value based on one or more of: a commanded travel speed for the power machine or a pressure in the hydraulic circuit; and
selectively operate the hydraulic motor within a first displacement range or a second displacement range that is different from the first displacement range, the first displacement range having a first minimum displacement and a first maximum displacement and the second displacement range having a second minimum displacement and a second maximum displacement, the first maximum displacement being the same as the second maximum displacement and the first minimum displacement being smaller than the second minimum displacement;
wherein operating the hydraulic motor within the first and second displacement ranges includes:
changing a run-time displacement of the hydraulic motor based upon the determined control value, including preventing a maximum run-time displacement from exceeding the first or second maximum displacement, respectively, and preventing a minimum run-time displacement from being below the first or second minimum displacement, respectively.
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