Mechanical seal

A mechanical seal comprising:

• a pair of seal rings that rotate relative to each other;
• and
• a retainer that holds one of the seal rings, wherein
• the retainer includes an annular base portion, an annular holding portion that is externally fitted to an outer periphery of the seal ring, and an annular connection portion that connects the annular base portion and the annular holding portion in an axial direction, wherein
• an annular space partially surrounded by the annular base portion, the annular connection portion, and the annular holding portion is formed between the outer periphery of the seal ring and an inner periphery of the retainer, wherein
• the retainer is provided with a plurality of beams which are disposed in the annular space to connect the annular base portion and the annular holding portion, wherein the beams are formed to divide the annular space into a radially inner space and a radially outer space, and wherein the radially inner space is defined by a surface of the annular base portion, an inner surface of the beam, a first surface of the annular holding portion, the radially outer space is defined by a surface of the annular connection portion, a second surface of the holding portion and an outer surface of the beam.