US 11,866,912 B2
Drive motor displacement control
Charles Young, Bismarck, ND (US); Marty Carpenter, Bismarck, ND (US); Scott Becker, Bismarck, ND (US); Douglas Kallas, Mandan, ND (US); Matthew Kaldor, Bismarck, ND (US); Eric Zabel, Bismarck, ND (US); and Boston Zachmann, Mandan, ND (US)
Assigned to Doosan Bobcat North America, Inc., West Fargo, ND (US)
Filed by Doosan Bobcat North America, Inc., West Fargo, ND (US)
Filed on Sep. 21, 2020, as Appl. No. 17/026,387.
Claims priority of provisional application 62/902,731, filed on Sep. 19, 2019.
Prior Publication US 2021/0087792 A1, Mar. 25, 2021
Int. Cl. E02F 9/22 (2006.01); F16H 61/47 (2010.01); F16H 61/421 (2010.01)
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
OG exemplary drawing
 
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.