There are two general approaches to mounting conveyor bearings into roller tubes and variations on both of those styles.
- Press Fit. The roller tube diameter is slightly smaller than the body of the bearing and the bearing is pressed mechanically or hydraulically into the tube using a special adapter. Click for a detailed discussion of Press Fit Conveyor Bearing mounts and variations.
- Press & Swage Fit (also known as Crimp Fit). The roller tube diameter is slightly smaller than the body of the bearing and the bearing is pressed mechanically or hydraulically into the tube using a special adapter. Perimeter edge of the roller tube is mechanically or hydraulically “crimped” tight to the body of the bearing using special tooling designed for that purpose. Click for a detailed discussion of Swage Fit Conveyor Bearing mounts and variations.
The following are FRANTZ general mounting guidelines applicable to both Swage Fit and Press Fit mounts. Quality mounting is directly proportional to the life of the bearing and its performance
- Care should be taken to cut all tubes to the proper length to avoid thrust loading the bearing due to insufficient distance between side rails after installation.
- The tube should be reamed or mandrel sized to produce an optimum .003” to .005” interference fit 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 bend will shorten normal life.
- Lugs on axle should be proper distance apart so that when the spring is installed and in a relaxed position, there is a 1/8th inch clearance between the spring and inner bearing race.
- The actual bearing mounting 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 to provide uniform pressure. The adapter must conform to the exact shape of 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 end of the tube.
- Rotate the tube on the two outer most portions of the axle. Any detection of reciprocating movement of the inner race along the length of the axle is indicative of a bearing not mounted perpendicular to its rotation. The maximum allowable deviation from perpendicularity between the face of the bearing and the inner race is 1° 30” for normal life.
- Additional life can be obtained through periodic inspection and lubrication.