Patent ID: 6666022
Filing Date: 2003-12-23
Classification: B60K,B60L,B60W,B60Y,E02F,F02D,F15B,F16H,Y02T,Y10S

Abstract:
A drive apparatus of working machine comprising:an engine; a hydraulic pump connected to said engine and having a maximum input larger than an output of said engine; an electric motor concurrently serving as a generator which is connected to the output shaft of said engine and performs a generator action or an electric motor action; a battery for accumulating electric power generated by said electric motor concurrently serving as a generator; a first control device connected to said electric motor and said battery to switch the actions of said electric motor, the first control device charging said battery with electric power generated by rotation of said electric motor at the time of the generator action, and supplying electric power accumulated in said battery to said electric motor to rotate it at the time of the electric motor action; and a controller connected to said first control device, wherein when an input of said hydraulic pump is smaller than said output of the engine, said controller operates said engine between the set number of revolutions and the number of high idle revolutions of the engine and when the input of said hydraulic pump is larger than the output of said engine, said controller comprising means for reducing the input of said pump and operating said electric motor in the electric motor action using the electric power accumulated in said battery to supplement the output of said engine, so that said engine will be operated near the set number of revolutions.