JOINT DRIVING DEVICE FOR JOINT-TYPE WORKING MACHINE

摘要

PURPOSE:To provide joints with effective assist force without enlarging the size and weight of an electric motor as a power means by providing a fluid- pressure actuator for assisting joint driving according to load torque. CONSTITUTION:At the non-assist time, the pressures of input-output ends of a fluid-pressure actuator become both high, thereby generating no difference. Accordingly, even if the fluid-pressure actuator 40 is connected to a driving shaft through connecting members 34, 60, no interference is generated to an electric motor 24 as a power means. At the time of needing assistance, the joint driving of the motor 24 can be immediately assisted through the constantly connected connecting means 34, 60 by switching an oil passage by a low pressure side oil passage switching means 58.