How Drive Tracks and Wheels Work

A pool robot gets around on motor power, grip and a bit of water pressure. The tracks and wheels are where that power meets the pool surface.

The parts in the chain

• Drive motor. One maker's parts overview has a single electric motor running the wheels or tracks and the pump that creates suction¹. Details are in drive motor basics.
• Drive wheels or pulleys. They take the turning motion and pass it to the track. On one maker's design, a belt-and-pulley system converts motor rotation into track movement².
• Tracks. These are the rubber or synthetic belts that look like small tractor tracks. One source describes a drive motor "connected to tractor-like rubber or synthetic tracks"³.
• Idler wheels. One maker also calls this the tension wheel. Moving it sets how slack the track is⁴.

What the wheels and tracks do

• Carry the weight. One maker says they "support the weight of the unit"⁴.
• Give grip. The same source says they "provide grip on the pool floor, walls and waterline"⁴.
• Move the brushes. On at least one design the brushes turn as the tracks move across the surface².

Other things that help it climb

Wheels and tracks aren't working alone. Wikipedia names three natural principles behind movement³:

• Traction and movement from the drive motor and tracks.
• Buoyancy from air held inside the machine.
• Force from water pushed out of the top, which presses the unit against the floor and walls.

So a robot can lose grip because of a worn track, a clogged filter or weak water flow. Don't assume the track is the culprit until you've checked the rest.

Tracks versus wheels

• Tracks wrap around wheels and carry the tread.
• Independent wheels each turn on their own axle, and each should rotate freely⁴.
• Which one your robot has depends on the model. The parts diagram in your manual will show it.

Track tension

• A track that's a little loose isn't always worn out. One maker says "A loose track does not always need to be replaced"⁴.
• On many models the tension can be set by moving the idler wheel slightly away from the drive wheel⁴.
• The way to do it differs by model. Use your manual, and don't guess at a screw.
• Follow the maker's rule on grease. The same source says lubrication should only be used when the maker specifies it⁴.

Why this matters for wear

Because the tread is the part that rubs on the pool, it's usually the first thing to show age. A checklist of what to look for is on the track wear page.