Sealing device for insertion between two relatively rotating members and associated transmission assembly for vehicles

A transmission assembly for vehicles comprising:

• a rolling bearing or a wheel hub unit comprising:
• a rotatable radially inner ring coupled integrally with a constant velocity joint;
• and
• a stationary radially outer ring coupled with a vehicle suspension upright;
• and
• a sealing device disposed on the constant velocity joint between the inner and outer rings,
• the sealing device comprising:
• a substantially rigid first annular screen integrally coupled with a first elastomeric annular element;
• and
• a substantially rigid second annular screen arranged coaxially with the first screen and facing the first elastomeric annular element,
• wherein:
• the first screen comprises a first radially outer portion comprising a first L-shaped portion;
• the second screen comprises a second radially outer portion comprising a second L-shaped portion facing towards, and axially and radially spaced from, the first L-shaped portion;
• the first L-shaped portion comprises a first annular sealing lip and a second annular sealing lip, the first and second annular sealing lips cooperating without contact with the second L-shaped portion to form with the second L-shaped portion a radial sequence of labyrinth seals arranged hydraulically in series with each other between the first screen and the second screen;
• the first annular sealing lip is located entirely radially inward of a radially outer end of the second L-shaped portion;
• the first screen comprises a third annular sealing lip, arranged radially inward of said first and second annular sealing lips and cooperating in sliding contact, with a predetermined axial interference, with the second screen;
• the second screen is coupled integrally with the rotatable inner ring and the first screen is coupled integrally with the stationary outer ring;
• a first flange portion of said first L-shaped portion and a first flange portion of said second L-shaped portion are arranged axially adjacent to the outer ring and occupy part of an axial space between said rolling bearing or wheel hub unit and said constant velocity joint,
• a rotational speed signaling element or encoder, made of an elastomer or plastic, is mounted on a flange portion of the second L-shaped portion,
• the second screen forms a predefined axial gap with a radially inner side wall of a seat of the suspension upright for the rolling bearing or hub bearing unit;
• said predefined axial gap forms a labyrinth seal between the suspension upright and the second screen and is arranged radially upstream of said sequence of labyrinth seals;
• a centrifuging annular chamber is defined by said seat of the suspension upright and said constant velocity joint and the second screen and
• a radial annular gap is defined between the suspension upright and the constant velocity joint and configured for externally discharging contaminants from the centrifuging annular chamber.