Patent ID: 11971098
Assignee: KOMATSU LTD.
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F  B | IPC B  F

Claim 0:
1. A power transmission device disposed between a power source and a travel device, the power transmission device comprising:
a torque converter device including a torque converter and a lock-up clutch and configured to transmit power from the power source to the travel device;
a first hydraulic pump driven by the power source;
a second hydraulic pump driven by the power source;
a first oil channel for supplying hydraulic fluid from the first hydraulic pump to the torque converter;
a second oil channel for draining hydraulic fluid from the torque converter;
a third oil channel that communicates with the first oil channel and the second oil channel;
a fourth oil channel for supplying hydraulic fluid from the second hydraulic pump to a hydraulic apparatus;
a fifth oil channel that communicates with the fourth oil channel and an orifice;
a sixth oil channel that communicates with the fifth oil channel and an on/off valve; and
a seventh oil channel that communicates with the sixth oil channel and the pressure control valve,
a pressure control valve disposed in the second oil channel or the third oil channel; and
a controller configured to cause the pressure control valve to open and close,
the on/off valve being configured to be switched between an ON-state and an OFF-state by the controller, the ON-state being a closed state and the OFF-state being an open state,
the controller setting the pressure control valve to an open state when the lock-up clutch is in an engaged state, the controller setting the pressure control valve to the open state by setting the on/off valve to an ON-state.