Depending on their design, series and size, Kaydon Reali-Slim thin section bearings are fitted with one of the cages/separators shown in table below.
| Cage/separator type | Material | Designation code | Availability Bearing | ||
|---|---|---|---|---|---|
 | One-piece snap-type cage | Glass fibre reinforced PA66 | L | Types C and X | Standard: series KAA, NAA, SAA, JHA |
| One-piece snap-type cage | Stamped brass or non-metallic composite | P | Types C and X | Standard: all other series |
 | One-piece circular pocket cage | Glass fibre reinforced PA66 | G | Type A | Standard: series KAA, NAA, SAA, JHA |
| One-piece circular pocket cage | Stamped brass or non-metallic composite | R | Type A | Standard: all other series |
 | One-piece snap-type cage | Machined phenolic laminate | D | Types C and X | On request |
| One-piece circular pocket cage | Machined phenolic laminate | H | Type A | On request |
 | Two-piece, riveted, circular pocket cage | Machined phenolic laminate | K | Types A, C and X | On request |
 | Snap-type segmental strip | PA12 | N | Types C and X: d > 4 in | On request |
 | Circular pocket segmental strip | PA12 | J | Type A: d > 4 in | On request |
 | One-piece snap-type | PEEK | X | Types C and X | On request |
| One-piece circular pocket cage | PEEK | Q | Type A | On request |
| One-piece snap-type cage | Stamped brass | V | Types C and X | On request |
 | One-piece snap-type cage | Stamped stainless steel | T | Types C and X | On request |
 | One-piece circular pocket cage | Stamped stainless steel | U | Type A | On request |
 | Snap-type separator | Wire strip or segmented 17-7 PH stainless steel | M1 | Types A, C and X | On request |
 | Snap-type separator, balls not in each pocket | Wire strip or segmented 17-7 PH stainless steel | W | Types C and X | On request |
 | Helical coil spring separator | 300 series stainless steel | S | Types C and X | On request |
 | Spacer slugs separator | PTFE tubing | Z | Types C and X | On request |
 | Toroid ball spacers | PTFE or Vespel2 SP-1 polyamide | Z | Type A | On request |
 | Spacer balls (< diameter than load carrying balls) | Steel (ABMA Standard 10) | Z1 | Type A | On request |
1: Requires filling slot(s) for radial contact and four-point contact ball bearings.
2: Vespel is a registered trademark of DuPont Polymers, Inc.
The principal function of a bearing cage/separator is to space the rolling elements uniformly and prevent contact between them. Very small differentials in rolling element motion result from differences in individual rolling element loads and the inherent elasticity of bearing and mounting components. Without a cage/separator, some rolling elements will eventually contact each other.
When request, the Kaydon bearings are also available with a full complement of balls. Full complement radial contact and four-point contact ball bearings require filling slot(s).
Due to the shape of the rolling elements and the opposite direction of motion of the contacting surfaces, a combination of relatively high contact stress and rapid motion is possible. Full complement bearings can experience abrasion of the rolling elements and raceways that affects bearing life and torque characteristics. This can limit the use of full complement bearings to low-speed applications where relatively large torque variations can be tolerated.
Orientation and positioning
It is suggested that in applications where the kaydon bearing axis will be within 45° of the vertical, the bearing be oriented with the cage pocket openings facing downwards, or that a shoulder of the shaft or housing be extended for added confidence of retention of the cage/separator.
Kaydon capped bearings (with seals or shields) have this orientation instruction etched on their outside diameter surface, shown by an arrow and the word "UP".
Snap-type cages
Snap-type cages are designed for use in bearing types C and X. this type of cage are installed after the conventional assembly of the rings and balls, and are retained in position as the prongs of the alternate "snap" pockets deform elastically to snap over the balls.
Snap-type cages centred on the balls at ambient temperature, become outer ring shoulder guided or inner ring shoulder guided when temperatures cause differential thermal expansion or contraction.
Close control of roundness and wall thickness helps provide effective piloting in either case, limiting deflection of the cage prongs and friction between the cage and ring shoulders for smooth operation.
Different materials are available for unusual operating conditions, including stainless steel and non-metallics such as phenolic laminate, PTFE and PEEK.
stainless steel cages are used in stainless steel bearings or high temperature applications for corrosion resistance.
phenolic laminate is used where light weight and/or lubricant absorption is desired.
the snap-type non-metallic cage is ideal for high-speed applications of bearings too small in cross section for the two-piece riveted cage (bearing with cross section to code C and smaller); it is also desirable in low-speed, minimum torque applications. Please refer to Kaydon designation system.
Circular pocket cages
One-piece cages
One-piece circular pocket cages are designed for use in bearing type A. This type of cages are positioned around the inner ring, with the balls placed in pockets before the outer ring is expanded thermally and dropped over the balls.
One-piece circular pocket cages have a method of assembly that permits the use of more balls than in the conventional design bearings, types C and X.
One-piece circular pocket cages have standard cages of brass, non-metallic composite and glass fibre reinforced PA66; also furnished in phenolic laminate, stainless steel and aluminum
Two-piece riveted cages
Two-piece riveted circular pocket cages are designed for use in non-standard thin section bearings of types C and X. And they are installed after the conventional assembly of the rings and bearing, and riveted together.
Two-piece riveted circular pocket cages are limited for use with bearings with a cross section to code D and larger (refer to Kaydon designation system), because of the space required for rivets.
As with snap-type cages, both of these styles are centred on the balls at ambient temperature becoming either outer ring shoulder guided or inner ring shoulder guided as the temperature changes.
Segmental separators
Segmental separators of either the snap-type or circular pocket design offer advantages for certain applications:
- When larger diameter bearings are subjected to high temperatures, expansion differentials between the separator and the rings may exceed the normal clearances provided.
- When oscillatory motion, variable loading and a vertical axis combine to cause differential rolling element travel with no load, torque may become unacceptably high or erratic.
A segmental separator may consist of a one-piece open ring or it may be composed of two or more segments:
- Where differential expansion creates a problem, sufficient clearance is provided between the ends of the open ring or between the several segments to allow for this expansion.
- Where torque is of concern, the selection of the number of segments is made based upon experience.
- In all other respects, segmental separators satisfy the above descriptions for snap-type cages or circular pocket cages.
Formed wire separators
When the need exists for maximum capacity and therefore the greatest possible number of rolling elements, formed wire separators:
- may be used to avoid the disadvantages of a full complement bearing;
- are most successfully used in bearing type A, where the greater number of balls can be installed without considering the use of filling slot(s);
- should be restricted when used in bearing types C and X to very low-speed applications.
Comparatively high wear rate coupled with relatively small cross section can cause the wear of the wire separator to be a limiting factor in the life of a bearing, especially if the loads are high. However, where weight or space are at a premium and the added load capability is an important consideration, this separator may be considered a good compromise.
A Kaydon bearing with a wire separator and maximum allowable ball complement has a static load rating of 180% of the standard static load rating.