Technical Information - Frantz® Manufacturing

Frantz® Wheel and Bearing Division
-Technical Information-

Technical Information

Frantz® Conveyor Bearings and Wheels

On this site are shown various bearings and skate wheels adapted for conveyor use.

All bearings and wheels are standard, but not all are shelf items. Certain variations from standard can be furnished if quantities are sufficient. Estimates on special bearings may be obtained on request.

All bearings are designed for use in roller type conveyor installations, where use does not exceed load ratings.

Swage fit bearings are not designed to be used where subjected to any continuous end thrust or continuous operation without lubrication. Bearings used in continuous operations should be ordered greased or should be lubricated after installation and periodically thereafter.

None of our bearings are sealed against continuous exposure to dust, sand, flour, etc. A few bearings, as noted, are partly sealed, but these types are not designed as permanently sealed bearings. These should be ordered greased if to be used in continuous operations as they cannot be lubricated properly after assembly.

Most standard non-sealed bearings will be furnished zinc plated, without grease, except when ordered as greased.

Mounting Specifications

Care should be taken to cut all tubes to the proper length to avoid thrust loading the bearing through insufficient distance between side rails when installed.
The tube should be reamed or mandrel sized to supply a .003" to .005" interference fit, which is optimum, with .008" as an absolute maximum.
The tube should have adequate chamfers to allow the bearing proper seating.
Tube ends should be absolutely parallel to each other and perpendicular to the axis of rotation.
The tubes should be clean and free of grit and chips in the bore to prevent bearing contamination.
Axles should be clean and straight, any camber or bends will only shorten normal life.
Lugs on axle should be proper distance apart so when the spring is installed and in relaxed position, there is 1/8 inch clearance between the spring and inner bearing race.
The actual bearing mount should be done in as clean an environment as possible.
In pressing the bearing into the tube, an adapter must be used to prevent cocking and provide uniform pressure. The adapter must conform to the exact shape f the outboard side of the bearing and sufficient diameter to cover the entire bearing with ample clearance for the inner race and axle extension. At no time should the axle or inner race be subjected to any force.
The bearing flange should come to bear solidly and squarely on the tube end.
Rotate the tube, supported by the two outer most portions of the axle. If you can detect any reciprocating movement of the inner race along the length of the axle, this is indicative of a bearing that is not mounted perpendicular to its rotation. The maximum allowable deviation from perpendicularity between the face of the bearing and inner race is 1° 30" for normal life.
Additional life can be obtained through periodic inspection and lubrication.

There is a fundamental equation in mounting bearings. Quality mounting is directly proportional to successful bearing life.

Packaging

Bearings can be shipped in steel drums or one of two sizes of corrugated paper boxes. The box sizes are 12" x 12" x 6" high or 12" x 12" x 12" high depending upon contents. The average weight per carton will vary from 60# to 150#. We can also furnish a bulk cardboard container which is approximately 28" x 35" x 20" high and contains about 1200# to 1400#.

Load Ratings

A formula has been developed by the Conveyor Equipment Manufacturers Association (CEMA) which enables one to estimate the load carrying ability of underground commercial bearings. If the diameter and number of balls used in a bearing are known, this formula may be used to estimate the "Basic Conveyor Bearing Load Rating," which is defined as that constant, radial bearing load which a group of apparently identical bearings can endure for 1,000,000 revolutions with 90% of the bearings surviving.

(Refer to Section 3 of CEMA Standard No. 401-1994)

Actual "Service Life" is dependent upon conditions surrounding the use of a bearing, such as temperature, dust, moisture, lubrication, shock, side loads, excessive speeds, installation procedures, etc. The CEMA Standard 401-1994 attempted to insert a "Service Factor" to allow for these factors in the calculation of load ratings. The determination of service conditions is however best done by the user of the bearings considering each application individually. It is for this reason that Frantz® Manufacturing does not attempt to apply a Service Factor to our load ratings.

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