Abstract: A The bearing-supported mechanical seal for a progressive including a cylindrical body (1), manufactured of steel or other materials (optional), with an internal centered sleeve (2), which fits perfectly the pump shaft/stem (3). It is equipped with two O-ring sets (4) for adjustment and sealing. The body (1) has housings for bearings (5), equipped with one or more roller bearings that will support all the stem reversions. The bearing-supported assembly seals are made by retainers (7A and 7B), installed on the roller bearing edges. The sealing assembly has two stationary seats (17) and one rotary seat (19), which has a closed lubrication system, composed by one reservoir (22), two communicating tubes (23), one pressure gauge (24) that operates under atmospheric pressure, and one pressure switch (25). The reservoir also has a drain (26) for replacing the lubricating oil and one relief valve (27), which could be opened or not.