The Series 400 has been designed to meet the emerging need for a high and low speed, free wheeling Torque Limiter. The Series 400 differs from previous ball detent designs by using two sets of balls on concentric pitch circles.

In the normal drive condition, torque is transmitted through the drive balls ‘A’. The inner strut balls ‘B’ are designed to carry no load during this time.

Disengagement on overload
When the driven machine either jams or an overload occurs which is greater than the torque setting, the balls roll out of their seats and force apart the drive plate and the slide plate. The balls are retained by the cage plate and roll freely on the flat surface of the drive plate and slide plate.

Series 400 - Toque Limiter

Disengagement on overload

When an overload condition occurs, the drive balls roll out of their seats forcing the slide plate ‘C’ and drive plate ‘D’ apart.  The cage plate ‘E’, strut balls and drive balls all rotate until the cage plate hits a stop located in the slide plate.  At this point the spring pressure has been transferred from the drive balls to the strut balls. The strut balls prevent the drive balls from re-engaging  the drive plate.  The coupling or driven media attached to adapter ‘G’ is now completely free to rotate.  Although the Series 400 has been designed to run freely after disengagement, it is recommended that a shut-down switch is incorporated to avoid wear.

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