This invention relates to a washing /drying machine which protects the user from high current formed as a result of the static electricity during the operation and minimizes the electromagnetic radiation.
The washing machines are grounded to prevent the damage for the user, see e.g.
In the prior art, it is grounded over the electric motor. The static electricity on the drum and the tub is transferred to the motor and to the body by means of a belt comprising a conductive material and grounding line respectively. The connection of the electric motor to the grounding line causes high level of noise. In order to avoid the noise on the phase and neutral lines due to the high level of noise on the grounding line, a filter comprising an inductance is used at the electricity connection inlet of the washing machine. Electromagnetic radiation can not be lowered to an acceptable level in accordance with the standards without the use of inductances, see e.g.
The object of this invention is to provide a washing /drying machine which protects the user from high current formed as a result of the static electricity during the operation and minimizes the electromagnetic radiation.
The washing/drying machine realized in order to attain above mentioned objects of the present invention has been illustrated in the attached drawings, wherein;
The washing/drying machine (1) which is the subject of this invention comprises a body (2), a tub (3) preferably from plastic material in which the washing cycle is performed, a drum (4) in the tub (3) rotating around its own axis to which the laundry is loaded, a motor (5) preferably with serial character and brushes which rotates the drum (4), a belt (6) which transfers the movement of the motor (5) to the drum (4) and is produced from non-conductive material to prevent the transfer the static electricity on the motor (5) to the body (2), one or more support (8) preferably from plastic material which is mounted on the feet of the motor (5) and used to prevent the transfer of the static electricity on the motor (5) to the body (2), a drum shaft (7) around which the drum (4) rotates, an RF filter (9) which reduces the electromagnetic radiation at the supply electricity inlet and a grounding connection (10) providing the discharge of the static electricity on the drum (4).
RF filter (9) is a capacitive filter consists of asymmetric capacitors placed between phase (P) and neutral (N) lines and symmetric capacitors placed between phase (P) or neutral (N) and grounding line (PE).
The grounding line (PE) from the supply is connected to the body (2). Motor (5) is in an isolated position by means of the belt (6) and the support (8). The static electricity on the motor (5) is not transferred to the body (2). Therefore the noise on the grounding line (PE) is reduced and a simple structured RF filter (9) is used to minimize the electromagnetic radiation.
As the tub (3) is made of plastic material, the static electricity on the drum (4) is discharged to the body by means of the grounding connection (10) with the drum shaft (7).
In another embodiment of the invention, the tub (3) is produced from metalic material. In this embodiment the static electricity on the drum (4) which is transferred to the tub (3) is transferred to the body (2) by means of the grounding connection with any point on the tub (3).
In the washing/drying machine which is the subject of this invention, static electricity on the motor (5) is not transferred to the body (2) by means of the non-conductive belt (6) and plastic supports (8) and the electromagnetic radiation is reduced by the use of only one capacitive RF filter (9). This enables reduced manufacturing costs.
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