Servomotor featuring a servovalve controlling a hydraulic drum motor

A servomotor comprising:

• a housing having an axis;
• a cover on one axial end of said housing;
• a substantially parallelopiped enclosing plate on the other axial end of said housing;
• cylinder head means in said housing and having a surface inclined to said axis;
• a motor shaft journalled in said cover and said enclosing plate;
• a drum rotating on said motor shaft and including two pistons slidable in said drum and biased against said surface of said cylinder head;
• a distribution port in said enclosing plate for each said piston;
• a servovalve having supply and use openings on a first surface thereof, said first surface being in fixed fluid tight contact with one surface of said enclosing plate;
• first axial bore means in said cover plate for each said piston, each said first bore means communicating with each said distribution port;
• second axial bore means in said cover plate for each said first axial bore means, each said second bore means having one end extending to said one surface of said enclosing plate for communicating with said use openings of said servovalve;
• third bore means extending perpendicular to said first and second bore means and communicating each said first bore means with a corresponding second bore means;
• two transverse bore means connecting each of said third bore means;
• two way safety valve means in said at least one transverse bore, wherein said enclosing plate further comprises two fourth bore means having one end extending to said one surface of said enclosing plate for communicating said servovalve supply openings with two outside connection channels joined respectively to a high pressure source and a non-zero low pressure source, said connection being effected by means of a connection block applied onto a second surface of said plate, the other end of said fourth bore means extending to said second surface of said plate.