The device and principle of operation of the washing machine machine, how it works

Currently, various mechanical devices such as washing machines help us to take good care of our clothes. Today they are found in almost all homes and most of us cannot imagine life without these devices.

Modern washing machines surprise with innovations thanks to which they save energy by washing clothes efficiently. Their history has come a long way from a primitive device to an automatic washing machine.

General information

For the first time a machine for washing clothes was described in 1752 under the name "Yorkshire Maiden". It consisted of a wooden tank that could be closed with a lid and filled with laundry and hot soapy water. In the center of the lid was a wooden block with a handle at the top for turning, and at the bottom was located wooden disc with recessed wooden pins that moved the laundry in soapy water by turning back and forth. The size of this machine and the manual mode made it suitable for small households.

Modern washing machine

A modern machine usually requires a connection to a power source, fresh water and waste water. Some devices do not heat water with electricity and instead use natural gas or (additionally or exclusively) are connected to a central hot water supply.

The washing cycle in such machines is divided into different time phases. Automatic machines that are common today provide sequencing automatically, with the electronics usually controlled by a microcontroller.

During the wash cycle, the machine releases detergent and fills the drum with water, moving the garment around an imaginary axis so that each item is thoroughly cleaned. This soapy liquid is then drained and clean water is added for the rinse cycle, which is then removed with the remaining soap. The drum then spins rapidly, removing about 80 percent of the excess water in the garment.

Features available in modern household washing units:

• timer for delaying the start of the wash cycle;
• predefined programs for different types of laundry;
• rotation speed settings;
• variable temperatures, including cold wash.

In Europe, most washing machines are drum machines in which the drum rotates around a horizontal axis. This type of machine distinguishes between a front loader and a top loader. For front loaders, the loading door is located at the front of the washing machine, and the top loaders load the drum wash from above. There is a bathtub around the washing drum, which can be made of stainless steel or plastic.

On most machines, the washing drum is driven by a motor using a V-belt. Meanwhile, other manufacturers have also developed so-called direct drive machines, in which the motor is located on the wash drum.

In the upper part of the unit there are control elements and a drawer for detergents and care products.

Household machines usually have only one cold water connection. When starting a wash program, water flows out of the water supply through the appropriate detergent hose. Through the holes of the washing drum, the washing solution enters the drum.

For the washing process, the wash solution is heated by a heating rod to the set temperature. The higher the set temperature, the more energy is required to heat the water. After rinsing or rinsing, the drain pump delivers rinsing solution or rinsing water, which is passed through the drain hose to the drainage system.

Machines with a circulating system have two pumps: a drain pump and a circulating pump. The drain pump flushes the water out of the tank, while the circulation pump ensures that during washing, the rinsing solution returns to the drum through the connecting hose.

Today washing devices are divided into semi-automatic and automatic. Semi-automatic machines are equipped with washing programs. It is possible to control such a unit only by defining the necessary parameters manually using the temperature switches, washing programs, and spin speed. These machines are simpler but less functional.

The principle of operation of the machine is automatic

The vending machine may seem like a more complicated device.. But such a machine does not need help - it will do everything by itself:

• will determine the weight of the loaded laundry;
• will pump as much water as needed;
• load how many detergents you need;
• will determine the washing time.

In addition, she will analyze the tissue and how dirty it is. Based on the received data, the machine will start washing. During operation, the color display will show data on water temperature, drum rotation speed during spinning, etc. There are many sensor sensors in the machine - they report on the quality of water, temperature and other parameters.

Over time, manufacturers of automatic machines have gone to great lengths to keep costs down. For example, more expensive gearboxes are no longer required as the motor speed can be electronically controlled.

The device and operation of washing machines

The body of the machines consists of sheet steel, which can be:

• enameled;
• galvanized;
• painted;
• made of stainless steel.

In some models, the body consists of a self-supporting frame that is firmly connected to the rear wall. The front panel, side panels and cover can be removed with minimal effort. This frame design allows easy and quick repairs in the event of service.

Top and front loaders have a device cover, which is usually made of scratch, abrasion and high temperature resistant material. For loading / unloading, they are opened using the open button (unlock button).

Front loaders are loaded and unloaded through the filling hole. It can be up to 40 cm in diameter. The door opening angle can be up to 180 °. The door glass is heat-resistant and double-glazed in some appliances for thermal insulation and noise reduction.

Some manufacturers offer drum lighting to provide better visibility when loading and unloading. To keep energy consumption as low as possible, the light is automatically turned off.

Special insulating materials are used to reduce noise on the components and on the case.

Washing drum

The washing drum is made of stainless steel and is installed with the possibility of rotation in a special bath. One-sided drum rotation is provided for front loaders, one-sided or two-sided drum rotation for top loaders.

The washing drum has a capacity of 40 to 55 liters, and some appliances have a capacity of 56 to 72 liters. The drum has holes for faster water penetration.

To facilitate loading and unloading, some models are equipped with a 10 ° or 15 ° inclined rear drum. The inside of the drum is equipped with stainless steel or plastic ribs. They are part of the washing mechanics, lifting the laundry out of the water and throwing it back, or rinsing the water from a certain height.

For a good wash result and optimal care behind garments for different textiles, there are devices with asymmetric drivers, that is, one side is rounded, which results in a lower drop height, and one side is flat.

To ensure that the laundry is completely dampened, some automatic washing machines operate according to the water wheel principle. With shovels, holes or pads on the outside of the drum, water is introduced and transported upward as the drum moves.

Rapid water penetration also achieved by an additional circulation pump.

Dosing compartments

Depending on the manufacturer, the machines are equipped with a different number of spacious compartments (from 2 to 4) to add detergents and care products:

• pre-wash compartment, soaking agent;
• compartment for softener, stain remover or bleach;
• compartment for the main wash;
• compartment for a freshener.

Washing and care products are rinsed automatically. Automatic cleaning of the dosing chamber after the end of the program prevents contamination.

Dosing chamber for automatic dosing

A suitable dosing chamber is used to fill the inner containers with liquid detergent or softener. The liquid agent and fabric softener can thus be dosed automatically.

Automatic dispensers

Separate containers of powder or liquid detergentthat are connected to the washing machine and placed nearby also allow the storage and automatic dispensing of detergent.

Water supply

For water inlet, a hose is connected to the drinking water line. Water supply is carried out through solenoid valves that open and close by program control at a specified time. The pressure in the water supply network supports the opening and closing processes.

The valve is equipped with a water flow regulator, which ensures a constant supply of water at different pressures in the line. If the water pressure is higher than 10 bar, a pressure reducing valve must be installed in the supply line. At water pressure below 1 bar special manufacturer's precautions must be observed.

There are filters upstream of the flow regulator to prevent dirt particles from entering the valve from the water line.

Washing devices are equipped with 1-3 solenoid valves. With three solenoid valves, there is a separate valve for each flush chamber.

To achieve a faster penetration of water into the laundry and, therefore, for better rinsing with minimal water consumption, the machines are equipped with additional water rinsing methods. On some devices, the door glass is beveled, which ensures quick and complete wetting of the laundry.

In the case of devices with fast moistening technology, the laundry is quickly wetted with the help of an additional injection nozzle and a quick exchange of water during washing is ensured.

In the case of a direct wash system, water is fed directly into the laundry through a nozzle during the water supply and flows from the top. Thus, the detergent is automatically rinsed out.

Water supply control

The duration of the water supply can be dependent on the level or the set time.

At a control level dependent level, the water levels are determined by level controllers, also called level controllers. There are mechanical and analog level controllers.

Mechanical level controls, called pressure monitors, are sealed pressure cells with a membrane that are connected to the bathtub through a hose. When the desired water level is reached, the air pressure in the pressure box increases. Thanks to the arched diaphragm, the solenoid valve is closed via the contact system and the water supply is interrupted. With a mechanical level regulator, different water levels are set.

Analog level controllers, called pressure transmitters, are electronic level controllers. They have the property of a semiconductor. They react to rising water levels and increased air pressure with a change in electrical resistance and, therefore, a change in electrical voltage.

Water level regulators are also used as dry protection, as the heating is only switched on when reaching a certain level, as well as for protection against flooding and as foam detectors during washing. At the beginning of the wash program, a sufficient amount of water is supplied until the water level corresponding to the wash program is reached and the level regulator responds. The engine then turns the drum.

Automatic loading

The amount of water supplied depends not only on the selected wash program, but also on the absorbency of the laundry.

The amount of water entering is recorded at the beginning of the wash program and is used to calculate the amount of rinsing water. This process is called automatic quantity.

Heat

Heating occurs mainly with the help of tubular heaters in the bath, less often - with the help of a water heater outside the bath.

Heating power max. 2.3 kw. For some devices, the specific surface area is reduced by increasing the heating area.

Electronic controllers are used to control temperature. Their task is to establish, limit and maintain a constant lye temperature. The temperature can either be continuously adjusted up to 95 ° C or programs can be permanently assigned.

Thermistors are used for electronic temperature control. These semiconductors work on the principle of electrical conductivity, which changes when heated. When voltage is applied to the thermistor and the circuit is closed, current flows through it and acts like a resistor. The electrical resistance of thermistors decreases with increasing heating

Electronic temperature controllers are highly accurate and, in combination with microprocessor control, provide a high level of safety.

Drive unit

The drive (motor) moves the washing drum at different speeds in an alternating direction of rotation (reverse). The drum speed depends on the program. Rotating speed ranges from 400 to 1800 U / min.

Different motors are used for the drive:

Universal motors (commutators, commutator motors) for AC or DC operation. Equipped with electronic control components, these motors offer a wide range of applications.

Individual speeds, speed combinations are different. For example, for optimal distribution of the laundry by slightly accelerating the drum during rotation, for foaming, etc. Universal motors are used on machines with different rotational speeds. Their maximum speed is in the upper range.

High quality machines are equipped with a breaker. Here the universal motor is supplied electronically with rectified, smoothed voltage pulses.

Three-phase asynchronous motors with frequency inverter control (FI control): these motors are not require the use of carbon brushes, therefore they are wear-resistant and operate very quietly, even at high speeds.

Direct drive is another new development in this area. The drive motor is permanently connected to the drum drive shaft, so the drive belts are no longer needed. This means that the space behind the drum can be used better and the depth of the drum can be up to 30% deeper. Due to the central position, the vibration of the actuator is reduced. The noise reduction due to the elimination of the drive belt is about 10%.