Permanent magnet retarder, component description

W43.40-1100-06

Location

1 Permanent magnet retarder

The permanent magnet retarder (1) is integrated in the drivetrain between the transmission output shaft and the propeller shaft.

Task

The permanent magnet retarder (1) is a wear-free auxiliary brake. Powerful permanent magnets are used instead of solenoids. The permanent magnet retarder (1) generates a braking torque of max.

650 Nm.

W43.40-1081-76

Design

2 Transmission

3 Stator adapter

4 Actuator cylinder

5 Stator

6 Rotor adapter

7 Output flange

8 Rotor

Y159 PMR solenoid valve

W43.40-1025-81

Function

Retarder switched off (I)

When switched off, the pole pieces (9) and the permanent magnets (10) are offset with respect to each other. Each permanent magnet (10) bridges two pole pieces (9).

The magnetic flux of the magnetic field is inside the stator (5) and has no effect on the rotational direction of the rotor (8). The rotor (8) turns freely in the direction of rotation (arrow A).

Retarder switched on (II)

When the PMR solenoid valve (Y159) is energized, it releases the compressed air supply to the actuator cylinder (4). The actuator cylinder (4) then turns the yoke (11) with the permanent magnets (10) in the stator (5) of the permanent magnet retarder (1). In the switched-on state, a permanent magnet (10) is then positioned directly opposite each pole piece (9).

The loop of the magnetic flux passes through the rotor (8) and affects the rotational direction of the rotor (8). Strong eddy currents are produced which counteract (arrow B) the rotational direction (arrow A) of the rotor (8) and thus generate a braking torque of max. 650 Nm.