Compact EGR valve

A valve comprising:

• a valve housing defining a valve chamber with an inlet opening communicating with a cylindrical portion of the valve chamber and an outlet opening communicating with the cylindrical portion of the valve chamber;
• a valve member within the cylindrical portion of the valve chamber, the valve member having a cylindrical side wall and an annular leading edge, the valve member moveable between a closed position where the cylindrical side wall covers the inlet opening and an open position where the cylindrical side wall does not cover the inlet opening;
• a drive mechanism comprising:
• a screw coupled to the valve member for axial and rotational movement with the valve member, said screw having a first thread and defining an axial bore;
• a nut secured in a fixed position and having a second thread engaged with said first thread so that rotation of the screw moves the screw and the valve member axially relative to the nut while rotating the valve member within the cylindrical portion of the valve chamber;
• a motor having a shaft received within the screw, said shaft having a constant non-round configuration along its length, said motor shaft received in the bore defined by the screw,
• wherein rotation of the motor shaft rotates the screw relative to the nut to move the screw and valve member axially relative to the nut and motor, said screw sliding along the shaft as the valve member moves axially between the closed position and the open position, said valve member rotating with the motor shaft and screw during axial movement.