Stud type track rollers are similar in their construction to single and double row yoke type track rollers, except that the raceway is formed by a heavy-section roller stud with a fixing thread and lubrication hole.

Due to the thick-walled outer ring with profiled outside surface and the rolling element set, they can support high radial loads as well as axial loads arising from slight misalignment and skewed running; they are suitable for applications such as cam gears, bed ways and conveying equipment.

The series PWKR(E) are supplied in an X-life design. Due to a modified material and the optimised raceway geometry of the outer rings, the basic rating life has been increased by up to 30%.

The static and dynamic load carrying capacity has also been increased. At the same time, the stress placed on the mating track has been reduced as a result of the optimised lateral surface profile and its improved surface quality.

Due to these measures, highly robust bearing arrangements with an extended operating life can be achieved.

Stud type track rollers with a crowned outside surface are predominantly used since they are often inclined in relation to the mating track and edge stresses must be avoided.

In series KR, the radius of curvature is R = 500 mm. The series KR..-PP, KRE..-PP, KRV..-PP, NUKR, NUKRE, PWKR..-2RS and PWKRE..-2RS have an outside surface with the optimised INA profile.

In stud type track rollers with this curvature profile (Figure to Figure ):

• the Hertzian pressure is lower
• edge loading under tilting is lower
• wear of the mating track is reduced
• the operating life of the mating track is extended.

Stud type track rollers are available in several designs as well as with or without an eccentric collar.

Stud type track rollers without an eccentric collar do not have a defined adjustment facility in relation to the mating track on the adjacent construction. Stud type track rollers with eccentric collar: see link.

KR, KR..-PP have a cage, while the design KRV..-PP has a full complement needle roller set. The series NUKR and PWKR..-2RS have a full complement cylindrical roller set.

Stud type track rollers without a cage have the largest possible number of rolling elements and therefore have particularly high load carrying capacity. Due to the kinematic conditions, however, the speeds achievable with these bearings are somewhat lower than those achievable with the cage-guided stud type track rollers.

In KR, KR..-PP and KRV..-PP, axial guidance is provided by the contact flange and contact washers.

The outer rings of series NUKR and PWKR..-2RS are guided by the rolling elements and ribs.

PWKR..-2RS-RR are protected against corrosion by the special coating Corrotect^®. For a description of the coating, see link.

Stud type track rollers are sealed on both sides. Series KR has gap seals, KR..-PP has a three-stage seal comprising plastic axial plain washers with formed seal lips on both sides of the bearing, NUKR has labyrinth seals and PWKR..-2RS has protected lip seals.

The three-stage PP seal is described on link.

The bearings are greased using a lithium complex soap grease to GA08 and can be lubricated via the roller stud. Relubrication can be carried out using Arcanol LOAD150.

Designs with an eccentric collar can be adjusted by means of a hexagonal socket on the flanged or threaded side of the roller stud. The outer ring outside surface can thus be adjusted against the mating track; as a result, less accurate manufacturing tolerances on the adjacent construction can be tolerated. Furthermore, this gives improved load distribution when using several stud type track rollers and also allows preloaded linear systems to be easily realised.

The highest point of the eccentric collar is indicated on the roller stud side, the eccentricity e is stated in the dimension tables. This is also the location of the radial relubrication holes which should lie in the unloaded zone of the rolling contact.

KRE..-PP has a cage, NUKRE and PWKRE..-2RS have a full complement cylindrical roller set.

Bearings without a cage have the largest possible number of rolling elements and therefore have particularly high load carrying capacity. Due to the kinematic conditions, however, the speeds achievable with these bearings are somewhat lower than those achievable with the cage-guided stud type track rollers.

In the series KRE..-PP, axial guidance is provided by the contact rib and contact washers. The outer rings of series NUKRE and PWKRE..-2RS are axially guided by the rolling elements and ribs.

The stud type track rollers are sealed on both sides. KRE..-PP has a three-stage seal comprising plastic axial plain washers with formed lips on both sides of the bearing, NUKRE has labyrinth seals and PWKRE..-2RS has protected lip seals.

For a description of the three-stage PP seal, see link.

The bearings are greased using a lithium complex soap grease to GA08 and can be lubricated via the roller stud. Relubrication can be carried out using Arcanol LOAD150.

The eccentric collar covers the radial lubrication hole in the shank. Relubrication must therefore be carried out via the end faces.

Stud type track rollers can be used at temperatures from –30 °C to +140 °C. In sealed bearings (suffix 2RS), the temperature range is restricted to between –30 °C and +120 °C.

Note the information on the operating temperature range in Technical Principles, Lubrication.

Stud type track rollers KR..-PP, KRV..-PP and KRE..-PP are suitable for operating temperatures from –30 °C to +100 °C, restricted by the grease and seal material.

Suffixes for available designs: see table.