Pressurized fluid engine equipped with means for selecting its speed of rotation

A pressurized fluid engine system comprising:

• a rotary cylinder block mounted for rotation about an axis of rotation;
• first and second groups of radial cylinders provided in said rotary cylinder block;
• a piston mounted for movement in each of said cylinders to define a work chamber of variable volume;
• a plurality of fluid passageways in said rotary cylinder block with each of said fluid passageways communicating on one end with the work chamber of one of said cylinders and having an open outer end in a transverse plane face of said cylinder block oriented perpendicularly to the axis of rotation of said cylinder block and with each open outer end being equidistantly spaced from each other and said axis of rotation;
• a source of pressurized work fluid;
• a sump;
• a first fluid control valve;
• a three-position fluid control valve;
• first and second main supply conduits extending between said first fluid control valve and said second fluid control valve;
• said three-position fluid control valve including selectively movable means movable to a first position for connecting said first main supply conduit to said source of pressurized work fluid and said second main supply conduit to said sump and to a second position for blocking the first and second main supply conduits and to a third position for connecting said first main supply conduit to said sump and said second main supply conduit to said source of pressurized work fluid;
• and wherein
• said first fluid control valve includes a valve housing, a piston valve mounted for axial positioning in a housing bore in said valve housing in a first position for directing pressurized work fluid to the fluid passageways in said rotary cylinder block to both groups of said cylinders to achieve low speed operation of said engine in a first direction when said three-position fluid control valve is in its first position or in a reverse direction when said three-position fluid control valve is in its third position and a second position for directing pressurized work fluid to only a selected one of said groups of cylinders to achieve high speed operation of said engine when said three-position fluid control valve is in its first position or in a reverse direction when said three-position fluid control valve is in its third position while simultaneously providing substantially unpressurized work fluid to the cylinders of the non-selected group of cylinders.