Crawler-type work machine

Patent metadata

Field	Value
Publication number	US-12522293-B2
Application number	US-202118253842-A
Country	US
Kind code	B2
Filing date	Dec 15, 2021
Priority date	Jan 21, 2021
Publication date	Jan 13, 2026
Grant date	Jan 13, 2026

Abstract

In a crawler type work machine, when switching from a pivot turning mode to a straight travel mode or a slow turning mode, a controller is configured to maintain a rotation speed of the turning motor until after a first timing at which the inside steering clutch begins partial engagement.

First claim

The invention claimed is:

1 . 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 rotate about the input shaft and switch between transmitting and blocking rotational power from the input shaft to the left and right output shafts using 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 to cause the crawler-type work machine to travel in a straight travel mode, a slow turning mode, or a pivot turning mode, in the straight travel mode, the controller being configured to cause the left and right steering clutches to engage, cause the left and right steering brakes to disengage, and stop the turning motor; in the slow turning mode, the controller being configured to cause the left and right steering clutches to engage, cause the left and right steering brakes to disengage, and drive the turning motor; in the pivot turning mode, the controller being configured to cause an inside steering clutch corresponding to a steering direction of the left and right steering clutches to disengage, and cause an inside steering brake corresponding to the steering direction of the left and right steering brakes to brake, and drive the turning motor; and when switching from the pivot turning mode to the straight travel mode or the slow turning mode, the controller being configured to maintain a rotation speed of the turning motor until after a first timing at which the inside steering clutch begins partial engagement.

2 . The crawler-type work machine according to claim 1 , wherein
when switching from the pivot turning mode to the straight travel mode or the slow turning mode, the controller is configured to stop the turning motor at or before a second timing at which the inside steering clutch is completely engaged.

3 . The crawler-type work machine according to claim 1 , wherein
the left and right planetary gear mechanisms each have
a ring gear coupled to the input shaft,
a sun gear rotatably attached to the input shaft and coupled to the respective steering clutch,
a planetary gear disposed between the ring gear and the sun gear, and
a carrier coupled to the planetary gear and the output shaft.

4 . The crawler-type work machine according to claim 3 , further comprising:
left and right clutch gears configured to separate from the sun gear of the respective planetary gear mechanisms using the left and right steering clutches, and to rotate in opposite directions; and an idler gear configured to transmit rotational power from the turning motor to the left and right clutch gears.

Assignees

• Komatsu Mfg Co Ltd

Inventors

• Yoshikawa Takeshi
• Takeshima Hiroaki
• Akiyama Naoya
• Nakata Kazushi
• Yatsuda Osamu
• Otaka Shinichi
• Nameki Yuji
• Nagasaka Ryoichi
• KOMURA Takaomi

Classifications

• E02F9/225 Primary

  Control of steering, e.g. for hydraulic motors driving the vehicle tracks (steering in general B62D) · CPC title

• B62D11/183 Primary

  Control systems therefor · CPC title

• B62D11/04

  by means of separate power sources · CPC title

• B62D11/003

  Electric or electronic control systems · CPC title

• E02F9/22

  Hydraulic or pneumatic drives {(for dipper or bucket arm position control E02F3/43, for blade position control for graders E02F3/844; for turntables E02F9/121; for fork-lift trucks B66F9/22)} · CPC title