Motor Grader Circle Drives24M Motor Grader
The largest Motor Grader is the 24. It contains two circle drives. All of the smaller Cat Motor Graders have a single circle drive. The circle drive rotates the blade or moldboard.
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Motor Grader Circle Drive
Circle Drive Gear Box
Circle Drive Hydraulic Motor
The circle drive gear box is driven by a hydraulic motor. The hydraulic motor runs on hydraulic oil.
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Motor Grader Circle Drive
Circle Drive Pinion Gear
Circle Drive Gear
A bottom view of the circle drive box shows the pinion that turns the large drive gear. The only place for dirt to enter the circle drive is through the shaft seal behind the pinion gear.
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Drive Group – Circle from SIS
This exploded view shows the complexity of the design. In addition to the gears and bearings, there is a set of clutch disks and separator plates. This clutch pack is used to absorb the shock loading that comes through the blade.
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Friction Disks
Rolling Element Bearings - steel
The components that generate most of the wear metals are shown in this view. The driven worm gear could be made of Brass or Aluminum.
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Motor Grader Circle Drive
Driven Worm Gear – aluminum
steel
The worm drive gears are all steel. The bearings on the gear shaft are tapered roller bearings. The spine on the left is where the hydraulic motor attaches to the drive gear. The image on the right shows an aluminum worm driven gear.
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Motor Grader Circle Drive
Wear on a Brass Worm Gear
The brass driven worm gear in these images has an abnormal amount of wear. This wear should show up as visible debris on the sample bottle cap. It will also show up as elevated Cu in the oil sample.
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Motor Grader Circle Drive
This chart identifies the driven worm gear in the current motor grader models. At this time, there are two driven gears. The brass gear is an alloy of Cu, Zn, and Al. The aluminum gear is an alloy of Al and Cu.
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Motor Grader Circle Drive
Fe: worm drive gear, bearings, separator plates
Al: driven worm gear
Remember, this is gear compartment without oil filters.
The help items identify some possible sources of wear metals in these compartments. These interpretations are not easy. Some wear metals may come from multiple components within the circle drive box.
Material
Motor Grader Circle Drive