Wash this way

Sept. 21, 2000
Washing clothes is not thought of as one of life's great pleasures. But Sears, Roebuck & Co. and Whirlpool Corp. are out to change that notion.

Eliminating the agitator increases capacity to 3.4 ft3 , letting the washer handle 20-lb loads.

The washer plate replaces the agitator in the Kenmore Elite washer.

Let's face it — washing clothes is not thought of as one of life's great pleasures. But Sears, Roebuck and Co. and Whirlpool Corp. are out to change that notion. They have joined forces to bring new technology to washers that will revolutionize how you wash clothes.

Before the turn of the century, many people used washboards to scrub their clothes. The wringer washer followed which evolved from a wooden tub to a more sophisticated metal design. This required a lot of time spent in the laundry room running clothes through a wringer after washing and rinsing. The 1940s brought the first automatic washer. This platform has evolved to today's more sophisticated washers, but with limitations. Sears and Whirlpool have taken washing clothes to a whole new level with the Kenmore Elite washer with Calypso wash motion.

This washer features a new technology — a washer sans agitator. No agitator means a bigger basket that holds more clothes. It also gives a gentler wash that can be used for a wide variety of fabrics. But if there's no agitator, how do clothes get clean? Read on.

No, it's not a new dance. It is, however, the key technology behind the Elite washer consisting of a wash plate and wavelike motion, similar to a ship rocking on the ocean. The wash motion lifts and bounces clothes while showering them with a concentrated slurry of soap and water. A force filter under the basket traps dirt and particles, flushing them out so clothes never sit in dirty water.

The wash plate, moving around a central pivot point, replaces agitators found in conventional toploading machines. While front-loading machines have no agitator, clothes are washed by tumbling through water. Traditional top-loading machines with agitators twist and pull clothes. Conversely, with no agitator, the Calypso wash motion is gentler and less stressful on clothes.

The heart of the wash plate is a die-cast aluminum U-joint consisting of two axes with eight needle bearings that let the plate tilt. The U-joint and bearing system carry the maximum load.

Clothes are washed in three ways — through mechanical action, chemical action, and thermal action. By gently lifting and bouncing clothes, the Calypso wash motion moderates the mechanical action. Using the recommended amount of detergent and mixing it with water forms a concentrated slurry, changing the chemical action. Thermal action — the effect of water temperature — remains the same.

Dispensers for detergent, bleach, and fabric softener at the top of the cabinet are timed and released according to the CPU. Software algorithms manage the whole wash process and prevent potentially troublesome situations. For example, if too much of the wrong detergent is used, there will be over-sudsing. In the spin cycle, suds flow out and fill the cavity between the basket and wall of the tub. The suds break down into a thick, viscous solution similar to shaving cream. The viscous drag can load down the motor and stop the basket, terminating the cycle prematurely. The algorithms predict the situation and activate a suds-lock correction mode. Fresh water showers clothes at low, 60-rpm speeds to flush out the excess suds, spinning them out in approximately 5 to 7 min and allowing the washer to finish the cycle.

The drive and pump motors are acoustically isolated and sit beneath the wash tub in the cabinet. The adaptive variable-speed drive motor provides multiple functions: it nutates or wobbles the wash plate; levels the plate for spinning; and spins. The drive motor is driven with variable voltage, current, and frequency, letting the machine perform different functions while using 65% less energy than traditional washers. For example, the nutating speed varies from 150 rpm for delicate fabrics to 300 rpm for heavy-duty fabrics. Spin cycles ramp up to 800 rpm compared to 640 rpm on typical washers. A V-belt connects the motor to the driveshaft.

The washer has two CPUs. One is dedicated to the variable-speed motor, while the second controls all other machine functions such as the front panel controls and pressure switches. Control algorithms allow for improved suspension performance by monitoring the condition of the clothes load during spin. The machine knows the difference between an unusual condition, such as an imbalanced load, and normal operation. If a load is imbalanced, the machine senses the torque variations in the variable-speed drive motor, stops, and corrects the imbalance before completing the spin. The second CPU also controls a permanent split-capacitor motor that drives the bidirectional, regenerative pump. A serial bus is used to communicate between the two CPUs. Two pressure switches are in the washer, one for the automatic water-level control and a second switch for protection. If the first switch fails, the second switch signals the CPU, activating a pump-out algorithm. The first switch provides the right amount of water based on the size and type of clothing load. At all times approximately 1 gallon of working solution is available from the sump pump.

The basket is stainless steel and has a 3.4-ft 3 capacity, handling up to 20-lb loads. For means of comparison, super-capacity washers hold 15 to 17-lb loads, and normal capacity washers hold approximately 10 to 13 lb. With the additional room freed up by eliminating the agitator, items previously taken to the laundromat, such as a queen-size comforter or sleeping bag, can now be washed at home. The larger-capacity basket does not mean that the Elite washer is a water hog. In fact, because the tub never completely fills with water, the washer uses up to 46% less water than a conventional Kenmore washer. Sound-quality jury studies with consumers guided Whirlpool engineers to not only minimize sound but to focus on the quality of the sound, such as effectiveness and gentleness. Engineers then isolated motors, the pump, and basket spinning sounds, recording and remixing until the quality factors matched the consumers' preferences. Design variations presented to juries focused on the relationships between the three mechanisms, giving engineers the feedback necessary to finalize specifications.

Pads on the front and side panels of the cabinet also muffle sound, as does a fiberglass wrap around the basket. The motors sit on rubber dampers to isolate vibration and noise. The lid of the washer has a molded sound dome with an integral seal to deaden washing sound.

A water-filled balance ring at the top of the basket automatically compensates for out of balance conditions. A proprietary elastomer on the feet of the machine minimizes vibration and walking, regardless of the condition of the floor.

For stopping power, a heavy-duty cam-actuated drum-brake system stops the basket in less than 7 sec, letting the lid be opened quickly, even after 800-rpm speeds. When the drive-motor power stops at the completion of a spin, the brake cam rotates, driving the actuation of the brake shoes which use bearing rollers as cam followers. The shoes rotate around a pinned axis, creating the motion to force the liner pads on the shoes against the brake drum. The pad's normal force is maintained by a balance between the force of the cam and coil spring. The friction force between the two liner pads and brake drum bring the basket to a smooth stop.

Keeping customer satisfaction in mind, an autofluff feature makes sure that clothes will never have to be peeled away from the sides of the basket. After the spin cycle stops, the wash plate nutates for approximately 1 min, effectively peeling the clothes away and fluffing them into the center of the basket for easy removal.

The Kenmore Elite washer with Calypso wash motion has a large capacity basket and high operating speeds, requiring a new suspension system with better damping qualities than traditional pedestal-mounted suspensions. The basket attaches to a spin tube at the bottom by a drive block. The basket sits and spins inside the plastic tub which rests on four pads on the tub support. The tub support is a welded steel assembly on which most parts, such as the motors, pumps, driveshafts, and brake are attached. The suspension is also attached to the tub support. Vertical suspension components link to the tub support legs and to the top corners of the cabinet frame by ball-and-socket joints. Ball-and-socket joints connect two dampers on the bottom cabinet frame and tub support. The universal joint permits three distinct machine functions with only two directions of drive-motor rotation. Clockwise rotation causes the wash plate to nutate, or wobble, during wash and rinse cycles. Counterclockwise rotation at low speeds is through a slip clutch, a lost-motion mechanism that levels the wash plate. Accelerating to high speeds engages the clutch, which spins the basket and clothes to drive out water.

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