1.Structural features and operating
principle This type of holdback is located using a
bearing in which several shaped wedges are arranged in the raceway
formed by inner race and outer race in a certain pattern so that it
operates stably, the outer race is connected with two end covers,
while the end covers are connected with the antirotation arm into
an integral part through pins and the antirotation arm is limited
by the fixed antirotation seat. When the motor operates normally,
the holdback makes the wedges deflect by a certain angle through
mechanics principle using the special geometry of the wedges so as
to be in light contact with inner and outer race, thus reducing the
coefficient of friction and improving the service life of the
holdback. When the main motor needs to be shut down, the inner race
of holdback reverses under the action of gravity of elevated
material to drive the wedges to deflect and bring the inner race
and outer race of the holdback to be wedged into an integral part
so as to effectively prevent the motor from reversing. Therefore,
this type of holdback is the most ideal non-reversing protector for
conveying equipment such as large belt conveyor, bucket elevator
etc. 2. Service
environment The ambient temperature for holdback
operation is **0~*0℃, when the holdback is running, it will
generate certain heat, so the ambient environment should be well
ventilated, the temperature of the holdback running at allowable
highest speed can reach *0℃, in this case it is required to check
the effect on the motor equipment and take appropriate temperature
reduction measures, if necessary. When the ambient service
temperature exceeds *8℃ or when it operates in open air, effective
protective measures should be taken (for example, use ventilating
equipment or cooling equipment etc.). Around the holdback it is not
allowed to place corrosive chemicals for fear of damaging the
holdback seal 3.Model designation of the
holdback Example: NJD holdback with clockwise
rotational direction of inner race, the specification of **0 and
the installation hole diameter of **0mm; the model is
NJD***-S***0.
