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US 12,594,991 B2Granted
Crawler-type work machine
AssigneeKomatsu Ltd.
InventorsTakeshi Yoshikawa, Hiroaki Takeshima, Naoya Akiyama, Kazushi Nakata, Osamu Yatsuda, Shinichi Otaka, Yuji Nameki, Ryouichi Nagasaka, Takaomi Komura
Life of this patent
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Abstract
A controller provided in a bulldozer maintains the engagement of an inside steering clutch over a predetermined period beginning from a switching start point at which switching starts, when switching from a slow turn mode to a pivot turn mode, and when switching from the pivot turn mode to the slow turn mode, maintains the braking of an inside steering brake over a predetermined period beginning from a switching start point at which the switching starts.
Claims13
A crawler-type work machine comprising:
- left and right planetary gear mechanisms disposed between an input shaft and left and right output shafts;
- left and right steering clutches configured to be rotatable about the input shaft and switch between transmitting and blocking rotational power from the input shaft to the left and right output shafts by means of the left and right planetary gear mechanisms;
- left and right steering brakes configured to brake the left and right output shafts;
- a turning motor configured to cause the left and right steering clutches to rotate so that a rotation speed difference is produced between the left and right output shafts;
- a controller configured to control the left and right steering clutches, the left and right steering brakes, and the turning motor thereby causing the crawler-type work machine to turn in either a slow turn mode or a pivot turn mode,
- the left and right steering clutches and the left and right steering brakes being driven by supplying hydraulic fluid;
- in the slow turn mode, the controller causing the left and right steering clutches to engage, causing the left and right steering brakes to release, and driving the turning motor so that, among the left and right output shafts, a rotation speed of an inside output shaft corresponding to the turning direction becomes lower than a rotation speed of an outside output shaft opposite to the turning direction;
- in the pivot turn mode, the controller causing an inside steering clutch corresponding to the turning direction among the left and right steering clutches to release, and causing an inside steering brake corresponding to the turning direction among the left and right steering brakes to brake;
- and
- during at least one of switching from the slow turn mode to the pivot turn mode and switching from the pivot turn mode to the slow turn mode, the controller causing the inside steering clutch to engage or causing the inside steering brake to brake over a predetermined period after switching starts.
7 more elements
Dependencies are inferred from the claim text.