Carrier Rollers
Upper frame rollers that support and guide the track on its return run. Fixed and adjustable mounting configurations available.
Configurations
Fixed and adjustable mounting.
Fixed Mount
Standard replacement configuration
Standard configuration for machines where the track frame geometry is fixed and alignment is set at assembly. Lower complexity, direct bolt-on replacement for most bulldozer and excavator platforms.
Adjustable Mount
Alignment-adjustable configuration
Mounting bracket allows lateral adjustment of the roller position relative to the track frame. Used where track alignment requires periodic correction or where frame wear has altered the original geometry.
Engineering Details
Load Profile
Carrier rollers sustain continuous unidirectional tension from the upper track run — unlike bottom rollers which experience cyclical radial loading. Bearing geometry is optimized for this sustained load profile.
Seal System
Upper-mounted components are exposed to falling debris, dust, and water ingress from above. KSS carrier roller seals are specified for top-exposure environments with particle sizes typical of coal and mineral mining sites.
Shell Hardness
Outer shell case-hardened to resist wear from continuous track link contact. Hardness profile balanced between surface wear resistance and core toughness to prevent brittle fracture under shock loading.
Bearing Pre-Fill
Pre-filled lubrication reservoir maintains bearing lubrication through the full service interval without field re-lubrication. Controlled-flow geometry limits lubricant consumption under sustained load.
Field Context
Fewer carrier rollers means each one matters more.
Most bulldozer and excavator undercarriage systems run only one or two carrier rollers per side. Unlike bottom rollers where failure of a single unit can be partially absorbed by its neighbours, a failed carrier roller immediately affects the alignment geometry of the entire upper track run.
When a carrier roller seizes or loses its shell profile, the track begins to run in an irregular path on the upper frame. This creates lateral loading on the track links, accelerates bushing and pin wear, and increases the risk of track derailment — particularly on uneven terrain or during counter-rotation.
Because carrier rollers are high-position components, they are also exposed to contamination from above: dust falls into the bearing area rather than being washed away. KSS carrier roller seal systems account for this exposure — the sealing geometry is designed for top-loaded contamination, not just lateral ingress.
Find the right carrier roller configuration.
Fixed vs. adjustable mount, and compatibility with your track frame — contact our authorized service provider.