Washing machines come in a variety of sizes and styles, arguably one for every type of consumer. Although the public is very adamant about important characteristics such as size, shape and Energy Star compliancy, the inner-workings of the washers often go overlooked.
Just as computer shoppers are savvy about which operating system drives their CPU, major appliance shoppers will soon take note of whether their washers are powered by a belt and pulley system, are clutch-driven or feature a direct-drive operation.
The conventional belt and pulley system is what we typically find in the United States. In it's simplest form, a motor powers the network of belts and pulleys that internally operate the gears and spin the drum or work the agitator.
A clutch-driven system has fewer parts than the conventional belt and pulley operation, sharing some of the characteristics of the simpler direct-drive design. Using a clutch to engage the drum or agitator, the unit's wash and spin cycles are at least partially driven by the washer's motor. However, because a clutch is engaged for part of the cycle, power transfer from the motor to the laundry is still diminished when compared with a 100 percent direct-drive configuration.
Direct-drive washers are much simpler in their construction. These washers feature a tub that is directly connected to the operating motor, greatly reducing the number of parts that may wear down, as well as increasing energy performance and reliability.
LG was the first manufacturer to debut a horizontal-axis direct-drive washer in the United States. The LG Wash & Dry Combo with SenseClean made its U.S. debut in 1998 and is currently available at independent retailers nationwide.
Direct-drive differs from non-direct-drive systems in other ways as well. The traditional belt and pulley system uses the same amount of energy to spin the tub and work the agitator regardless of the weight of the load inserted. In a direct-drive unit, such as the LG Wash & Dry Combo, motor speed is variably controlled by an inverter, so the weight of the load is sensed and power output is adjusted accordingly.
The unique nature of direct drive also allows for a reduction in tangling of fabric. In traditional washers, the mechanical force placed upon the laundry is focused on the clothes nearest the agitator. Modern direct-drive systems help alleviate much of the damage by eliminating the need for the agitator, as debris is removed by the back and forth rotation of the drum — thus removing the most damaging part of traditional washing machines.
Structurally, the belt and pulley system naturally makes traditional clothes washers asymmetrical, therefore unbalanced and more prone to noise and vibration from motor operation. When a washer uses a direct-drive format, the motor and shaft that powers the drum is connected directly beneath (or in the case of our horizontal load unit, directly behind) the basin, making the washer structurally symmetric and helping to reduce unnecessary noise during the spin cycle.
Like most technologies, direct drive as it pertains to clothes washers will take a little bit of time to catch on. As more consumers realize the benefits of direct drive in terms of energy saving, reduction in clothes damage and noise, a greater number of manufacturers will be incorporating a direct-drive system into their high-end washers as well.
Editor's Note:This column was written in response to an article in which Fisher & Paykel contested LG's claim to be first-to-market with a direct-drive washer (see TWICE, Nov. 12, 2001, p. 42). While LG acknowledges that Fisher & Paykel's SmartDrive washers predate its own, product manager Young Noh makes the distinction between his competitor's clutch-drive system and LG's direct-drive design.