Electrohydraulic motor and hydraulic driving method

An electrohydraulic motor, comprising:

• hydraulic drive means for rotating an output shaft by a pressure of operation oil;
• electric drive means for rotating a drive shaft according to an inputted electric signal;
• drive switch means, connected to said hydraulic drive means, to a main oil passage for leading operation oil supplied from the exterior, and to a return oil passage for leading operation oil to the exterior, for switching connection between said hydraulic drive means and each of said main oil passage and said return oil passage;
• and
• connection switch means, connected to said main oil passage and said return oil passage, for changing connection between said main oil passage and said return oil passage,
• wherein said drive switch means responds to rotation of said drive shaft to thereby switch between a drive position, in which each of said main oil passage and said return oil passage is connected to said hydraulic drive means, and a neutral position in which connection between said hydraulic drive means and each of said main oil passage and said return oil passage is disconnected, and
• wherein said connection switch means is adapted to connect said main oil passage to said return oil passage in response to an operation of said drive switch means, and also adapted to break the connection between said main oil passage and said return oil passage.