Hydraulically controlled torque coupling device

A torque coupling device comprising:

• a hydraulic manifold block rotatable about an axis of rotation, said hydraulic manifold block including a plurality of axially extending first cylinder bores defined therein;
• a first multi-lobed cam ring rotatable relative to and coaxially with said hydraulic manifold block;
• a plurality of first pistons each disposed within corresponding one of said plurality of first cylinder bores in said hydraulic manifold block for reciprocating therewithin upon relative rotational movement between said hydraulic manifold block and said first multi-lobed cam ring, said plurality of first pistons engaging with said first multi-lobed cam ring at distal ends thereof;
• said plurality of first pistons defining a corresponding plurality of first variable displacement pressure chambers within said corresponding one of said plurality of first cylinder bores;
• a first restrictor device in fluid communication with each of said plurality of first pressure chambers such that said first restrictor device controls a discharge pressure attainable within each of said plurality of first pressure chambers during discharge strokes of said plurality of first pistons;
• and
• a first fluid reservoir disposed within said hydraulic manifold block for storing a supply of a hydraulic fluid, said first fluid reservoir is in fluid communication with each of said plurality of first pressure chambers and said first restrictor device.