Abstract: The brake or coupling system (1) comprises a first piston (2) arranged in a first piston cylinder (3) thereby forming a first piston chamber (5) and a second piston (8) arranged in a second piston cylinder (9) thereby forming a second piston chamber (10). The first piston (2) is adapted to be displaced between a braking position and a rest position. The first piston (2) is spring biased in the direction of its rest position, and the second piston (8) is adapted to adjust a distance (X) provided between a friction element (6) and a rotatable element (7) in the rest position of the first piston (2) by means of adjustment of a volume of hydraulic fluid trapped in the second piston chamber (10). At least one spring element is arranged to act between the first and second pistons (2, 8).

Abstract: The present invention relates in particular, but not limited to, a wind turbine hydraulic brake calliper. The brake calliper comprising a cylinder bore, a piston having a piston head and a piston skirt. The piston being received in the cylinder bore in an orientation where the piston head faces towards the brake pad. The calliper comprising a fluid connection connected to or connectable to a source of hydraulic fluid for leading hydraulic fluid into the void of the cylinder bore below the piston head (1b), so as to move the piston. The piston is formed at least partly and preferably solely from a polymeric material or from polymeric materials.

Abstract: The present invention relates in particular, but not limited to, a wind turbine hydraulic brake calliper. The brake calliper comprising a cylinder bore, a piston having a piston head and a piston skirt. The piston being received in the cylinder bore in an orientation where the piston head faces towards the brake pad. The calliper comprising a fluid connection connected to or connectable to a source of hydraulic fluid for leading hydraulic fluid into the void of the cylinder bore below the piston head (1b), so as to move the piston. The piston is formed at least partly and preferably solely from a polymeric material or from polymeric materials.

Abstract: The brake or coupling system (1) comprises a first piston (2) arranged in a first piston cylinder (3) thereby forming a first piston chamber (5) and a second piston (8) arranged in a second piston cylinder (9) thereby forming a second piston chamber (10). The first piston (2) is adapted to be displaced between a braking position and a rest position. The first piston (2) is spring biased in the direction of its rest position, and the second piston (8) is adapted to adjust a distance (X) provided between a friction element (6) and a rotatable element (7) in the rest position of the first piston (2) by means of adjustment of a volume of hydraulic fluid trapped in the second piston chamber (10). At least one spring element is arranged to act between the first and second pistons (2, 8).