A garden hose reel is a common variation of a wheel and axle. It's a simple machine that consists of a drum, axle, lever, inlet hose, brass hose connector and base. Garden hose reels are a convenient way to wind up long hoses for tangle-free storage.
The inlet hose connects the reel to the main water supply and the brass hose connector allows the gardener to screw a garden hose onto the reel. The hose wraps around the drum, the lever spins the drum, and the drum rotates on the axle. The lever provides a mechanical advantage based on the principle that Work = Force x Length of the Lever Arm. The longer the lever, the less force the user must apply to crank the wheel and wind the hose.
The base of the reel can be a wall mount, free-standing legs or a wheeled cart. Other parts included in a garden hose reel can be bushings and axle retainers that help keep the spinning motion smooth and the wheel in place; bolts and nuts; and other components unique to the model. Some reels come with water-powered automatic rewind features, smart tracks for even winding and hideaway covers that conceal the stored garden hose.