Date: February 28, 2002

EDT Bearing Selection Guides continued
Revised 2/02

11) Machine specific (customized) bearings must be spec’d from a BDC or with participation of someone intimately familiar with the machine. Customized bearings often have less room for error.

12) Modular plastic belt conveyors will always use NA Poly Rounds with a locking sleeve. These are covered by the EDT Guaranteed Solutions program to last for a minimum of one year.

13) When estimating the length of a conveyor for an application: figure each 90 degree bend in the conveyor as 3 times the length and each 180 degree curve as 6 times the length. Example a ten foot conveyor with one 90 degree bend has an equivalent length of 30 feet. With two 90 degree bends, the bearings on the 10' conveyor are handling the equivalent of 60 feet on a straight conveyor.10' with one 90 degree and one 180 degree bend is equivalent to a 90 foot straight conveyor when calculating bearing load. Normally you would see these kinds of designs on tabletop chain conveyors and are best left to ball bearings.

14) Abrasive contaminants (dust, flour, grains, sand and other solids) must be kept out of the working surface of the bearing. Grease is not recommended in dusty environments as it attracts and hold the contaminants in the bearing. Seals like Forsheda v rings are recommended to reduce solid contamination of the journal. If there is sufficient room, the EDT Glove® should be used. (The Glove® is available blind bored or thru bored.)

15) In high solid abrasive contaminated applications it is best to completely isolate and cover the bearing with the EDT Glove® . Since any covering that restricts airflow around a bearing will raise temperature, it is normally recommended to use a ball bearing inside of the EDT Glove®.

16) If there is not enough flushing liquid present in an application, a black residue may build up around the ID of a QB or QF bearing. This is normal, but may be unacceptable in a sanitary environment. The only remedy for this is to use an alternative material; call the factory for recommendations.