US 12,227,396 B2
Work machine
Masahide Zushi, Kagawa (JP); Kazu Nagahama, Kagawa (JP); Toshihiko Fukuoka, Kagawa (JP); and Manato Shirai, Kagawa (JP)
Assigned to TADANO LTD., Kagawa (JP)
Appl. No. 17/600,287
Filed by TADANO LTD., Kagawa (JP)
PCT Filed Apr. 3, 2020, PCT No. PCT/JP2020/015267
§ 371(c)(1), (2) Date Sep. 30, 2021,
PCT Pub. No. WO2020/204153, PCT Pub. Date Oct. 8, 2020.
Claims priority of application No. 2019-072143 (JP), filed on Apr. 4, 2019.
Prior Publication US 2022/0169484 A1, Jun. 2, 2022
Int. Cl. B66C 23/70 (2006.01)
CPC B66C 23/706 (2013.01) [B66C 23/708 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A work machine, comprising:
a telescopic boom including a first boom element and a second boom element that are telescopically overlapped with each other;
a telescopic cylinder that includes a fixing-side member and a movable-side member and extends and retracts the telescopic boom;
a housing fixed to the telescopic cylinder;
an electric drive source that is supported by the housing and drives using power supplied from a power source;
a first connecting mechanism that is housed in the housing and operates based on the power of the electric drive source and switches between a connected state and a disconnected state of the first boom element and the telescopic cylinder;
a second connecting mechanism that is housed in the housing and operates based on the power of the electric drive source and switches between the connected state and the disconnected state of the first boom element and the second boom element;
an electric circuit capable of switching between a drive state in which a supply of power from the power source to the electric drive source is allowed to drive the electric drive source, and a braking state in which the supply of power from the power source to the electric drive source stops to generate a braking force to be applied to the electric drive source; and
a control unit that controls the switching between the drive state and the braking state, wherein
the electric drive source is one electric motor,
the work machine further comprises a switch gear that selectively transmits the power of the one electric motor to any one of the first connecting mechanism and the second connecting mechanism,
the drive state includes a first drive state in which the one electric motor rotates in a first direction and a second drive state in which the one electric motor rotates in a second direction,
in the first drive state, the first connecting mechanism operates based on an output of the one electric motor transmitted via the switch gear,
in the second drive state, the second connecting mechanism operates based on an output of the one electric motor transmitted via the switch gear,
in the first drive state, the switch gear is connected to the first connecting mechanism and is not connected to the second connecting mechanism, and
in the second drive state, the switch gear is connected to the second connecting mechanism and is not connected to the first connecting mechanism.