Motors are widely used to power many devices and machines. The rotational power developed by a motor can be harnessed and directed by a belt. The belt can run in a pulley mounted on the shaft. Alternatively, the belt can run directly on the power shaft, wherein tension in the belt holds the belt in place on the power shaft.
One use of a motor is in a vacuum cleaner. A motor in a vacuum cleaner can power a driven device such as a vacuum fan unit, a powered brushroll, drive wheels, etc. However, the use of the vacuum cleaner in a dirty environment often leads to belt slippage. A motor-driven belt can slip due to excessive load on the driven device, for example. A powered brushroll can encounter an obstacle, such as a heavy carpet, that can slow or stall the brushroll, resulting in motor stall or belt slippage. Alternatively, a powered brushroll can accumulate fiber strands and other foreign objects that can slow or stall the brushroll. Another common belt slippage cause is the presence of lubricant or other foreign liquids on the belt. Yet another cause can be dirt, etc., between the belt and the shaft.
The slowing or stalling of a driven device can additionally cause the belt to move on the power shaft. Typically, the belt will move toward a side of higher belt tension. Therefore, if the belt is improperly aligned or improperly installed, the belt can move away from the desired running location on the power shaft. In severe cases, the belt can move completely off of the shaft. Another consequence is that the moving belt can contact a housing or wall structure next to the belt. For example, in a vacuum cleaner a power shaft and belt can be located in close proximity to an access door. If the belt moves on the power shaft, the resulting wearing action can damage both the belt and the vacuum cleaner structure.
One prior art approach has been to form a ridge or flange on the shaft to prevent moving of the belt. For example, a flange can be formed on the end of the shaft. However, this prior art approach does not prevent improper installation/alignment. This prior art approach does not move the belt to a desired alignment if the belt is improperly installed or aligned.