Designs and variants

SKF cam followers have a thick-walled outer ring with its running surface crowned as standard. However, cam followers with a cylindrical (flat) running surface are also available (designation suffix X).

SKF cam followers are available in three basic designs:

All three designs have the same main dimensions. They are available in different stud designs:
  • a concentric seat (fig. 4)
  • an eccentric collar (fig. 5, E at the end of the basic designation) on the stud
The eccentric collar has a shrink-fit onto the stud, enabling less stringent positioning tolerances to be specified for associated components. For values of the adjustable eccentricity → product table.
KR design cam followers
  • are available based on:
    • a needle roller and cage assembly (fig. 6)
    • a full complement needle roller set (fig. 7, V in the basic designation)
    Cam followers based on a full complement of needle rollers accommodate higher loads than same-sized cam followers with a cage.
  • have the outer ring axially guided by the pressed-on flange ring and the stud head (integral flange), forming a gap-type seal
  • are also available with an axial sliding ring on both sides (designation suffixes PPA, fig. 8, fig. 9 and fig. 10; PPSKA, fig. 11; or PPXA):
    • made of PA66
    • forming narrow labyrinth seals with the outer ring in a radial direction, to protect against coarse contaminants
    • serving as contact seals in an axial direction to retain grease reliably in the bearing
    • improving lubrication conditions in the cam follower, keeping friction and frictional heat low, and extending grease life

KR design cam followers, sizes 16 and 19

  • without a designation suffix or with the designation suffix PPA (fig. 8)
    • have one slot in the head of the stud that enables the stud to be held in place by a screwdriver during mounting
    • have a relubrication hole for a press-in grease fitting or a plug if relubrication is not required in the centre of the slot (→ Accessories)
  • with the designation suffix PPSKA (fig. 11)
    • have a hexagonal recess in the head of the studt hat enables the stud to be held in place by a hexagonal key (Allen wrench) during mounting
    • have no relubrication features

KR design cam followers, designation suffix B, sizes ≥ 22

  • have a hexagonal recess at each end of the stud (fig. 6), enabling the cam follower to be held in place by a hexagonal key (Allen wrench) during mounting
  • have a relubrication hole for a press-in grease fitting in the centre of each hexagonal recess
  • can accommodate adapters from a centralized lubrication system for sizes ≥ 35 (→ Accessories)
NUKR .. A design cam followers
  • are based on double row full complement cylindrical roller bearings without an integral flange between the two roller sets (fig. 12)
  • have the outer ring axially guided by the stud head and pressed-on flange ring via the roller sets
  • have a sheet metal angle ring pressed into the outer ring shoulder on both sides, forming an effective labyrinth seal
  • have a hexagonal recess at each end of the stud, enabling the cam follower to be held in place by a hexagonal key (Allen wrench) during mounting
  • have a relubrication hole for a press-in grease fitting or an adapter from a centralized lubrication system in the centre of each hexagonal recess (→ Accessories)
  • accommodate relatively heavy axial loads that can occur due to skew or tilting
PWKR ...2RS design cam followers
  • are based on double row full complement cylindrical roller bearings (fig. 13)
  • have the outer ring axially guided by the stud head and pressed-on flange ring via the roller sets
  • are fitted on both sides with an NBR contact seal, being integral with a sheet metal angle ring that is pressed into the outer ring shoulder, to press against the flange ring and the stud head
  • have a hexagonal recess at each end of the stud, enabling the cam follower to be held in place by a hexagonal key (Allen wrench) during mounting
  • have a relubrication hole for a press-in grease fitting or an adapter from a centralized lubrication system in the centre of each hexagonal recess (→ Accessories)
  • accommodate relatively heavy axial loads that can occur due to skew or tilting
Cages

Cam followers, if not a full complement of rollers, are fitted with a sheet steel window-type cage that is roller centred (fig. 14).

For information about the suitability of cages, refer to Cages and Cage materials.

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