Patent Description:
A washing machine is a machine for washing clothes using electric power, and generally includes a tub to store washing water and a drum rotatably installed inside the tub. The washing machine includes a drum type washing machine for washing laundry by raising and lowering the laundry while the rotating tub is rotating, and an electric washing machine to wash the laundry by using water flows generated by the pulsator when the rotating tub is rotated.

In the drum type washing machine, the rotating shaft of the drum is arranged in a substantially horizontal direction, so that the laundry is lifted up and dropped down in accordance with the rotation of the drum, thereby washing the laundry.

Meanwhile, the conventional drum type washing machine includes a lifter provided inside the drum for lifting the laundry upward. On the other hand, the conventional drum type washing machine is not provided with a pulsator to generating water flows inside the drum, unlike the electric washing machine.

<CIT> relates to a drum-type washing machine including a pulsator. <CIT> discloses a washing machine according to the preamble of claim <NUM>.

One aspect of the present disclosure discloses a washing machine having a pulsator but no lifter in a drum type washing machine.

Another aspect of the present disclosure discloses a washing machine capable of driving a drum and a pulsator separately in a drum type washing machine.

In accordance with the present invention, a washing machine is provided as set out in claim <NUM>.

Driving force of the first driving motor may be different from driving force of the second driving motor.

The second driving motor may be mounted on the rear surface of the tub
The first pulley may include a first base portion radially extending from the first shaft at the rear of the second driving motor, a first extending portion extending from the first base portion toward the drum, and a first coupling portion provided at an end portion of the first extending portion and connected to the first belt.

The first extending portion may be provided to be inclined to be closer to the drum near a radially outer side of the first pulley.

The washing machine may further include an idler connected to the first belt, wherein the first driving motor, the first pulley, and the idler may be connected to the first belt, forming the first rotational path.

The first pulley may include a first base portion extending at the rear of the second driving motor in the radial direction of the first pully, and a first coupling portion extending from the first base portion toward the drum to cover the second driving motor and to which the first belt is coupled.

The first driving motor may be configured to selectively rotate the pulsator in one of the same direction as the rotating direction of the drum and the opposite direction of the rotating direction of the drum.

The first shaft may be rotatably inserted into the second shaft.

The first pulley may be disposed to be spaced more from the drum than the second pulley is.

According to the present disclosure, a washing machine is provided with respective driving devices for driving a drum and a pulsator, thereby driving the drum and pulsator independently.

According to the present disclosure, the washing machine may drive the drum and the pulsator independently to improve washing performance and shorten the washing time.

According to the present disclosure, the washing machine may secure a washing space by not having a lifter that would be in the drum to lift the laundry.

Like reference numerals or symbols denoted in the drawings of the present disclosure represent members or components that perform substantially the same functions.

The terms herein used are for describing exemplary embodiments of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the scope of the present disclosure as defined by the appended claims. It will be understood that when the terms "includes," "comprises," "including," and/or "comprising," when used in this specification, specify the presence of stated features, figures, operations, components, or combination thereof, but do not preclude the presence or addition of one or more other features, figures, steps, components, members, or combinations thereof.

It will be understood that, although the terms first, second, etc., may be used herein to describe various components, these components should not be limited by these terms. These terms are only used to distinguish one component from another. For example, a first component could be termed a second component, and, similarly, a second component could be termed a first component, without departing from the scope of the present disclosure. As used herein, the term "and/or" includes any and all combinations of one or more of associated listed items.

The terms "forward" and "rear" and the like used in the following description are defined based on the drawings, and do not limit the shape and position of each component.

Hereinafter, a front loading type washing machine for throwing in laundry through the front of the washing machine will be described. However, the present disclosure is not limited to this type of washing machine, but is also applicable to a top loading type washing machine, in which laundry is loaded through the top of the washing machine.

Hereinafter, embodiments according to the present disclosure will be described with reference to the accompanying drawings in detail.

<FIG> is a side cross-sectional view illustrating a schematic configuration of a washing machine <NUM> according to an exemplary arrangement which does not form part of the invention.

Referring to <FIG>, the washing machine <NUM> may include a main body <NUM> forming an outer appearance and accommodating various components therein, a tub <NUM> provided inside the main body <NUM> to store water, a drum <NUM> that receives and rotates the laundry, a pulsator <NUM> provided inside the drum <NUM>, a first driving device <NUM> for driving the drum <NUM>, and a second driving device <NUM> for driving the pulsator <NUM>.

The main body <NUM> may have substantially a box shape. The main body <NUM> may have a front plate, a rear plate, a top plate, a bottom plate, and side plates. A laundry inlet 10a may be formed on the front plate to allow laundry to be thrown into the drum <NUM>.

The laundry inlet 10a of the main body <NUM> may be opened or closed by a door <NUM>. The door <NUM> may be pivotally coupled to the main body <NUM> by a hinge member. The door <NUM> may include a glass member and a door frame to support the glass member.

The glass member may be formed of a transparent tempered glass to allow the inside of the main body <NUM> to be seen from outside. The glass member may be provided to protrude toward the inside of the tub <NUM> to prevent the laundry from being biased toward the door <NUM> side.

The tub <NUM> may store water and may be formed in a substantially cylindrical shape. The tub <NUM> may be supported by a suspension <NUM>. The tub <NUM> may include a hollow cylindrical portion <NUM>, an opening <NUM> formed at one side of the cylindrical portion <NUM> to correspond to the laundry inlet 10a of the main body <NUM>, and a bottom portion <NUM> formed on another side of the cylindrical portion <NUM>.

Reinforcing ribs <NUM> (see <FIG>) of a lattice shape may be formed in the bottom portion <NUM> of the tub <NUM> at predetermined intervals in the radial direction and the circumferential direction. The reinforcing ribs <NUM> may prevent warping when the tub <NUM> is injected and may prevent the rear wall of the tub <NUM> from being twisted by the load delivered to the tub <NUM> during washing or dewatering.

The laundry inlet 10a of the front plate of the main body <NUM> and the opening <NUM> of the tub <NUM> may be connected by a diaphragm <NUM>. The diaphragm <NUM> may form a passage connecting the laundry inlet 10a of the front plate of the main body <NUM> and the opening <NUM> of the tub <NUM> and may direct the laundry thrown into the laundry inlet 10a to the inside of the drum <NUM> and may reduce transmission of vibration generated when the drum <NUM> is rotated to the main body <NUM>. In addition, the diaphragm <NUM> may seal between the tub <NUM> and the glass member of the door <NUM>.

The drum <NUM> may have a substantially cylindrical shape whose front portion is opened and may be rotatably provided inside the tub <NUM>. That is, the drum <NUM> may include an opening <NUM> formed in the front. The drum <NUM> may be arranged such that the central axis of the drum <NUM> is parallel to the central axis of the tub <NUM>.

The drum <NUM> is rotatable within the tub <NUM>. The drum <NUM> may perform washing by raising and lowering the laundry while rotating. A plurality of through holes <NUM> may be formed around the drum <NUM> to allow water stored in the tub <NUM> to flow therethrough. In addition, the drum <NUM> may include at least one protrusion <NUM> protruding toward the inside of the drum <NUM>. When the laundry is washed, the protrusions <NUM> may rub against the laundry to improve washing performance.

The drum <NUM> in this arrangement may be formed with a plurality of through holes <NUM> and/or protrusions <NUM> continuously formed along the circumferential surface of the drum <NUM> as no lifter is provided. That is, in the conventional washing machine, a lifter for lifting laundry is provided on a portion of the inner circumferential surface of the drum, and thus a plurality of through holes are not continuously formed along the circumferential surface of the drum. In other words, in the conventional washing machine, no through hole is formed at a portion where the lifter is provided. On the contrary, in the washing machine <NUM>, the plurality of through holes <NUM> and/or the protrusions <NUM> are continuously formed along the inner circumferential surface of the drum <NUM>, securing more washing space and allowing more water stored in the tub <NUM> to flow into the drum <NUM>, thereby improving washing performance.

The pulsator <NUM> may be disposed inside the rear of the drum <NUM> and may be provided rotatably with respect to the drum <NUM>. The pulsator <NUM> may be configured to be rotatable independently of the drum <NUM>. That is, the pulsator <NUM> may rotate in the same direction as the drum <NUM> or may rotate in a different direction from that of the drum <NUM>. A rotation axis of the pulsator <NUM> may be the same as the rotation axis of the drum <NUM>.

The pulsator <NUM> may generate water flow in the forward and backward directions inside the drum <NUM> during laundry. In the present disclosure, the pulsator <NUM> may improve the washing performance.

A water supply device <NUM> to supply water into the tub <NUM> may be provided at an upper portion of the tub <NUM>. The water supply device <NUM> may include a water supply pipe <NUM> through which to supply water from an external water supply source and a water supply valve <NUM> to open or close the water supply pipe <NUM>.

A detergent supply unit <NUM> to supply detergent to the tub <NUM> may be provided at a front upper portion of the main body <NUM>. The detergent supply device <NUM> may be connected to the tub <NUM> through a connection pipe <NUM>. The water supplied through the water supply pipe <NUM> may be supplied into the tub <NUM> together with the detergent via the detergent supply device <NUM>.

The washing machine <NUM> may include a drainage device <NUM> capable of draining water from the tub <NUM>. The drainage device <NUM> may include a drain pipe <NUM> connected to a lower portion of the tub <NUM> to guide the water to the outside of the main body <NUM>, and a drainage pump <NUM> to pump the water in the tub <NUM>.

<FIG> is a perspective view illustrating a tub and a driving device of the washing machine <NUM> shown in <FIG>. <FIG> is a side cross-sectional view illustrating the drum, the pulsator, and the driving device of the washing machine shown in <FIG>. <FIG> is a perspective view illustrating the pulsator and the first driving device of the washing machine shown in <FIG>. <FIG> is a perspective view illustrating the drum and the second driving device of the washing machine shown in <FIG>. <FIG> is a rear view of the tub and the driving device shown in <FIG>.

A driving device <NUM> including a first driving device <NUM> for providing power to the pulsator <NUM> and a second driving device <NUM> for providing power to the drum <NUM> is provided behind the tub <NUM>.

The first driving device <NUM> may include a first driving motor <NUM> that generates a rotational force to rotate the pulsator <NUM>, a first shaft <NUM> extending backward from the pulsator <NUM> and becoming the rotation axis of the pulsator <NUM>, a first pulley <NUM> connected to the first shaft <NUM>, and a first belt <NUM> connecting the first driving motor <NUM> and the first pulley <NUM>.

The first driving motor <NUM> may be fixed to the outside of the tub <NUM> and may provide power to the pulsator <NUM>. Specifically, the first driving motor <NUM> may be mounted on a portion of the lower end portion of the outer circumferential surface of the tub <NUM>.

The first driving motor <NUM> may include a first motor shaft 111a, which may further extend to the rear of the main body <NUM> than the second motor shaft 131a of the second driving motor <NUM> described later. With this configuration, the washing machine according to the present arrangement may be configured such that a first rotational path P1 formed by the first belt <NUM> connected to the first motor shaft 111a does not overlap a second rotational path P2 formed by the second belt <NUM> connected to the second motor shaft 131a. That is, the first belt <NUM> may be disposed not to interfere with the second belt <NUM>.

The first driving motor <NUM> may be a motor capable of both forward rotation and reverse rotation. Therefore, the first driving motor <NUM> may selectively rotate the pulsator <NUM> in one of the same direction as the rotational direction of the drum <NUM> and opposite direction to the rotational direction of the drum <NUM>. The first driving motor <NUM> may be a Brushless Direct Current motor (BLDC motor).

The first shaft <NUM> may be connected to the rear surface of the pulsator <NUM> and may extend from the pulsator <NUM> along the rotation axis of the pulsator <NUM>. That is, the first shaft <NUM> may extend to the rear of the pulsator <NUM>. The first shaft <NUM> may be a rotation axis of the pulsator <NUM>. The first shaft <NUM> may be formed separately from the pulsator <NUM> and coupled to the pulsator <NUM> without being limited thereto. For example, the first shaft <NUM> may be integrally formed with the pulsator <NUM>.

A first bearing <NUM> to rotatably support the first shaft <NUM> may be provided on the outer circumferential surface of the first shaft <NUM>. The first bearing <NUM> may be fixed to a second shaft <NUM>.

One end portion of the first shaft <NUM> may be connected to the pulsator <NUM> and the other end portion of the first shaft <NUM> may be connected to the first pulley <NUM> as will be described later. According to this configuration, the first shaft <NUM> may rotate the pulsator <NUM> by delivering the power that the first pulley <NUM> receives from the first driving motor <NUM> to the pulsator <NUM>.

The first shaft <NUM> may be rotatably inserted into the second shaft <NUM>. Accordingly, the first shaft <NUM> may rotate in the same direction as the second shaft <NUM>, or in the opposite direction to the second shaft <NUM>.

The first shaft <NUM> may be longer than the second shaft <NUM> and may be inserted into the second shaft <NUM> to protrude from either ends portion of the second shaft <NUM>. According to this configuration, the pulsator <NUM> connected to one end portion of the first shaft <NUM> may be disposed inside the drum <NUM> connected to one end portion of the second shaft <NUM> and the first pulley <NUM> connected to the other end portion of the first shaft <NUM> may be disposed at a farther distance from the drum <NUM> than the second pulley <NUM> connected to the other end portion of the second shaft <NUM> may be.

The first pulley <NUM> may be connected to the other end portion opposite of the one end portion of the first shaft <NUM> to which the pulsator <NUM> is connected. The first pulley <NUM> may include a first base portion 115a connected to the first shaft <NUM>, a first coupling portion 115b coupled to the first belt <NUM> as will be described later to guide the rotation of the first belt <NUM>, and a first extending portion 115c connecting the first base portion 115a and the first coupling portion 115b.

The first base portion 115a is fixed at the other end portion of the first shaft <NUM> so that the first shaft <NUM> rotates along with the first pulley <NUM> when the first pulley <NUM> rotates.

The first coupling portion 115b may be provided along the circumference of the first pulley <NUM> and may be connected to the first belt <NUM>. The first coupling portion 115b is connected to the first belt <NUM> so that the first pulley <NUM> may receive the driving force generated from the first driving motor <NUM>. The first pulley <NUM> may deliver the driving force received through the first coupling portion 115b to the first shaft <NUM> connected to the first base portion 115a.

At least one or more of the first extending portions 115c may extend along the radial direction of the first shaft <NUM> to connect the first base portion 115a and the first coupling portion 115b. However, unlike the arrangement shown in <FIG>, the first extending portion 115c may be provided such that one plate extends from the first base portion 115a to the first coupling portion 115b. The first extending portion 115c may deliver the driving force received from the first coupling portion 115b to the first base portion 115a.

In other words, the first pulley <NUM> may receive power from the first driving motor <NUM> and deliver it to the pulsator <NUM>. The first pulley <NUM> may be disposed at a farther distance from the drum <NUM> than the second pulley <NUM> may be, as will be described later.

The first belt <NUM> may deliver the power of the first driving motor <NUM> to the first pulley <NUM> by connecting the first driving motor <NUM> and the first pulley <NUM>. Specifically, the inner surface of the first belt <NUM> may be in contact with and engaged with the first motor shaft 111a of the first driving motor <NUM> and the first coupling portion 115b of the first pulley <NUM>. That is, rotation of the first belt <NUM> may be guided by the first motor shaft 111a of the first driving motor <NUM> and the first coupling portion 115b of the first pulley <NUM>.

The first belt <NUM> may be spaced apart from the second belt <NUM> by a predetermined distance d. Accordingly, the second belt <NUM> may not be interfered with by the first belt <NUM>.

The second driving device <NUM> may include a second driving motor <NUM> to generate a rotational force to rotate the drum <NUM>, a second shaft <NUM> extending backward from the drum <NUM> and serving as a rotation axis of the drum <NUM>, a second pulley <NUM> connected to the second shaft <NUM>, a second belt <NUM> connecting the second driving motor <NUM> and the second pulley <NUM>.

The second driving motor <NUM> may be fixed to the outside of the tub <NUM> and may provide power to the drum <NUM>. Specifically, the second driving motor <NUM> may be mounted on a portion of the lower end portion of the outer circumferential surface of the tub <NUM> other than the portion to which the first driving motor <NUM> is fixed.

The second driving motor <NUM> may include a second motor shaft 131a, and the second motor shaft 131a may extend to the rear of the main body <NUM> less than the first motor shaft 111a of the first driving motor <NUM> may do. According to this configuration, the washing machine according to the present arrangement may be configured such that the second rotational path P2 formed by the second belt <NUM> connected to the second motor shaft 131a does not overlap the first rotational path P1 formed by the first belt <NUM> connected to the second motor shaft 111a. That is, the second belt <NUM> may be disposed not to interfere with the first belt <NUM>. In other words, a first rotation plane PS1 formed by the first belt <NUM> may be provided not to overlap a second rotation plate PS2 formed by the second belt <NUM>. Specifically, the first rotation plane PS1 may be substantially parallel to the second rotation plane PS2.

The second driving motor <NUM> may be a motor capable of both forward rotation and reverse rotation like the first driving motor <NUM>. Accordingly, the second driving motor <NUM> may rotate the drum <NUM> in the first direction or in the second direction different from the first direction. The second driving motor <NUM> may be a BLDC motor like the first driving motor <NUM>.

In this arrangement, the second driving motor <NUM> may be the same driving motor as the first driving motor <NUM>. Specifically, the second driving motor <NUM> may be provided to have the same driving force as the driving force of the first driving motor <NUM>.

The second shaft <NUM> may be connected to the rear surface of the drum <NUM> and may extend from the drum <NUM> along the rotation axis of the drum <NUM>. That is, the second shaft <NUM> may extend backward from the drum <NUM>. The second shaft <NUM> may be a rotation axis of the drum <NUM>. The second shaft <NUM> may pass through the rear plate of the tub <NUM> to connect the drum <NUM> and the second pulley <NUM>. The second shaft <NUM> may be formed separately from the drum <NUM> and coupled to the drum <NUM> without being limited thereto. For example, it may be integrally formed with the drum <NUM>.

A second bearing <NUM> to rotatably support the second shaft <NUM> may be provided on the outer circumferential surface of the second shaft <NUM>. The second bearing <NUM> may be fixed to the tub <NUM>.

One end portion of the second shaft <NUM> may be connected to the drum <NUM> and the other end portion of the second shaft <NUM> may be connected to the second pulley <NUM>, which will be described later. According to this configuration, the second shaft <NUM> may rotate the drum <NUM> as the second pulley <NUM> delivers the power received from the second driving motor <NUM> to the drum <NUM>.

In addition, the second shaft <NUM> may have a hollow therein so that the first shaft <NUM> may be rotatably inserted to the second shaft <NUM>. Specifically, the hollow of the second shaft <NUM> may be formed to have a diameter larger than that of the first shaft <NUM> by a predetermined size so that the first shaft <NUM> may be inserted to the hollow to be rotated in the hollow. According to this configuration, the second shaft <NUM> may be rotated in the same direction as the first shaft <NUM>, or in the opposite direction of the first shaft <NUM>.

The second shaft <NUM> may be shorter than the first shaft <NUM> so that the first shaft <NUM> protrudes from either end portions of the second shaft <NUM>. According to this configuration, the rear plate of the drum <NUM> connected to one end portion of the second shaft <NUM> may be disposed rearward as compared with the pulsator <NUM> connected to one end portion of the first shaft <NUM>, and the second pulley <NUM> connected to the other end portion of the second shaft <NUM> may be disposed closer to the drum <NUM> than the first pulley <NUM> connected to the other end portion of the first shaft <NUM> may be.

The second pulley <NUM> may be connected to the other end portion opposite of the one end portion of the second shaft <NUM> to which the drum <NUM> is connected. The second pulley <NUM> may include a second base portion 135a connected to the second shaft <NUM>, a second coupling portion 135b coupled to the second belt <NUM> to guide the rotation of the second belt <NUM>, which will be described later, and a second extension portion 135c connecting the second base portion 135a and the second coupling portion 135b.

The second base portion 135a is fixed to the other end portion of the second shaft <NUM>, so that the second shaft <NUM> rotates along with the second pulley <NUM> when the second pulley <NUM> rotates.

The second coupling portion 135b may be provided along the circumference of the second pulley <NUM> and may be connected to the second belt <NUM>. As the second coupling portion 135b is connected to the second belt <NUM>, the second pulley <NUM> may receive the driving force generated by the second driving motor <NUM>. The second pulley <NUM> may deliver the driving force received through the second coupling portion 135b to the second shaft <NUM> connected to the second base portion 135a.

At least one second extension portion 135c may extend along the radial direction of the second shaft <NUM> to connect the second base portion 135a and the second coupling portion 135b. However, unlike what is shown in <FIG>, the second extension portion 135c may be provided such that one plate extends from the second base portion 135a to the second coupling portion 135b. The second extension portion 135c may deliver the driving force received from the second driving motor <NUM> to the second base portion 135a.

In other words, the second pulley <NUM> may receive power from the second driving motor <NUM> and deliver it to the drum <NUM>. The second pulley <NUM> may be disposed closer to the drum <NUM> than the first pulley <NUM> may be.

In this arrangement, the second pulley <NUM> may be the same pulley as the first pulley <NUM>. Specifically, the second pulley <NUM> may be provided to have the same size as that of the first pulley <NUM>. That is, the second pulley <NUM> may have the same diameter as the diameter of the first pulley <NUM>.

The second belt <NUM> may connect the second driving motor <NUM> and the second pulley <NUM> to deliver the power of the second driving motor <NUM> to the second pulley <NUM>. Specifically, the inner surface of the second belt <NUM> may be in contact with and engaged with the second motor shaft 131a of the second driving motor <NUM> and the second coupling portion 135b of the second pulley <NUM>. That is, rotation of the second belt <NUM> may be guided by the second motor shaft 131a of the second driving motor <NUM> and the second coupling portion 135b of the second pulley <NUM>.

The second belt <NUM> may be spaced apart from the first belt <NUM> by a predetermined distance d. Accordingly, the second belt <NUM> may not interfere with the first belt <NUM>.

In this arrangement, the second belt <NUM> may be the same belt as the first belt <NUM>. Specifically, the second belt <NUM> may be provided to have a length equal to the length of the first belt <NUM>.

In other words, the first driving motor <NUM>, the first pulley <NUM> and the first belt <NUM> of the first driving device <NUM> of the washing machine <NUM> according to the present arrangement may be identical to the second driving motor <NUM>, the second pulley <NUM>, and the second belt <NUM> of the second driving device <NUM>, respectively.

Hereinafter, operation of the washing machine <NUM> will be described.

The washing machine <NUM> may rotate the first driving motor <NUM> and the second driving motor <NUM> in opposite directions to rotate the drum <NUM> and the pulsator <NUM> in opposite directions during laundry. According to this operation, unlike the conventional washing machine that washes laundry by falling them only in the vertical direction, the washing machine <NUM> may wash the laundry by shifting the laundry not only in the vertical direction but also in the front-rear direction, and may also produce a water flow in a direction in which the laundry is twisted, thereby improving the washing performance and as a result, reducing the washing time.

On the other hand, the washing machine <NUM> may rotate the first driving motor <NUM> and the second driving motor <NUM> in the same direction in order to rotate the drum <NUM> and the pulsator <NUM> in the same direction during laundry. In this case, the washing machine <NUM> may perform the same operation as the conventional drum type washing machine.

The conventional washing machine is typically rotated at <NUM> rpm, and unable to do the laundry by falling if rotated at <NUM> RPM or more because the laundry is fixed to the inner circumferential surface of the drum by the centrifugal force. However, in the washing machine <NUM>, with the pulsator <NUM> provided inside the drum <NUM>, even if the drum <NUM> is rotated at high speed, the pulsator <NUM> drops the laundry, and thus the washing performance may be improved and the washing time may be reduced.

<FIG> is a perspective view illustrating a tub <NUM> and a driving device <NUM> of a washing machine according to an exemplary arrangement according to the invention.

A driving device <NUM> will be described with reference to <FIG>. However, the same components as those in the arrangement shown in <FIG> are denoted by the same reference numerals and description thereof may be omitted.

Referring to <FIG>, the driving device <NUM> may include a first driving device <NUM> and a second driving device <NUM>.

The first driving device <NUM> may include a first driving motor <NUM> to generate a rotational force for rotating the pulsator <NUM>, a first shaft <NUM> extending rearward from the pulsator <NUM> and becoming the rotation axis of the pulsator <NUM>, a first pulley <NUM> coupled to the first shaft <NUM>, and a first belt <NUM> connecting the first driving motor <NUM> and the first pulley <NUM>.

The first driving motor <NUM> of the first driving device <NUM> may be implemented with a motor having a less driving force than that of the first driving motor <NUM> of the first driving device <NUM> shown in <FIG>. Accordingly, the first driving motor <NUM> shown in <FIG> may have a smaller size than the first driving motor <NUM> shown in <FIG>.

Corresponding to the size of the first driving motor <NUM>, the first pulley <NUM> may be smaller in size than the first pulley <NUM> of the first driving device <NUM> shown in <FIG>. That is, the radius of the first pulley <NUM> shown in <FIG> may be smaller than the radius of the first pulley <NUM> shown in <FIG>.

In addition, corresponding to the size of the first driving motor <NUM> and the first pulley <NUM>, the first belt <NUM> may be smaller in size than the first belt <NUM> of the first driving device <NUM> shown in <FIG>. That is, the length and/or width of the first belt <NUM> shown in <FIG> may be smaller than the length and/or width of the first belt <NUM> shown in <FIG>.

The first shaft <NUM> may be connected to the rear surface of the pulsator <NUM> to be a rotation axis of the pulsator <NUM>. The first shaft <NUM> shown in <FIG> may be identical to the first shaft <NUM> shown in <FIG>.

The second driving device <NUM> may include a second driving motor <NUM> to generate a rotational force to rotate the drum <NUM>, a second shaft <NUM> extending rearward from the drum <NUM> and serving as a rotation axis of the drum <NUM>, a second pulley <NUM> coupled to the second shaft <NUM>, and a second belt <NUM> connecting the second driving motor <NUM> and the second pulley <NUM>. The second driving device <NUM> shown in <FIG> may be the same as the second driving device <NUM> shown in <FIG>.

As described above, with the reduced size of some components of the first driving device <NUM> of the driving device <NUM> in the washing machine according to this arrangement, more space may be secured inside the main body <NUM> and the material costs may be reduced. Although the first driving device <NUM> is illustrated as being reduced in size in <FIG>, it is possible to have a device with the same size or smaller size than the first driving device <NUM> shown in <FIG> for the first driving device <NUM> and a device with a smaller size than the second driving device <NUM> shown in <FIG> for the second device <NUM>.

In other words, the driving force of the first driving motor <NUM> may be different from the driving force of the second driving motor <NUM>, the size of the first pulley <NUM> may be different from the size of the second pulley <NUM>, and the length and/or width of the first belt <NUM> may be different from the length and/or width of the second belt <NUM>.

<FIG> is a side cross-sectional view illustrating the tub <NUM>, the drum <NUM>, the pulsator <NUM> and a driving device <NUM> of a washing machine according to an exemplary arrangement which does not form part of the invention.

Referring to <FIG>, the driving device <NUM> may include a first driving device <NUM> and a second driving device <NUM>. Hereinafter, the second driving device <NUM> will be described first rather than the first driving device <NUM> for convenience of explanation.

The second driving device <NUM> to rotate the drum <NUM> of the driving device <NUM> may be mounted on the rear surface of the tub <NUM>, and may include a second driving motor <NUM> and a second shaft <NUM>.

The second driving motor <NUM> may include an annular stator <NUM> and a rotor <NUM> that rotates relative to the stator <NUM>. According to this configuration, the second driving motor <NUM> may convert electric force into a mechanically rotational force by the stator <NUM> and the rotor <NUM>. In addition, the second driving motor <NUM> may be directly connected to the drum <NUM> via the second shaft <NUM> without a medium such as the second pulley <NUM>, unlike the second driving motor <NUM> shown in <FIG>.

The stator <NUM> may be fixed to the tub <NUM>, and the rotor <NUM> may be rotated by electromagnetic interaction with the stator <NUM>. The rotor <NUM> may be provided to cover the outside of the stator <NUM>.

The rotational force generated by the stator <NUM> and the rotor <NUM> may be delivered to the drum <NUM> through the second shaft <NUM>. The second shaft <NUM> may be connected to the rotor <NUM> and rotated along with the rotor <NUM>, and may penetrate the rear plate of the tub <NUM> to connect the drum <NUM> and the rotor <NUM>.

The second shaft <NUM> may have a hollow formed therein to allow the first shaft <NUM> to be rotatably inserted thereto. That is, the first shaft <NUM> may be provided to be rotatable with respect to the second driving motor <NUM> while passing through the second driving motor <NUM>. According to this configuration, the second shaft <NUM> may be rotated in the same direction as the first shaft <NUM> or in the opposite direction to the first shaft <NUM>.

The first driving device <NUM> may include a first driving motor <NUM> that generates a rotational force for rotating the pulsator <NUM>, a first shaft <NUM> extending rearward from the pulsator <NUM> and becoming the rotation axis of the pulsator <NUM>, a first pulley <NUM> coupled to the first shaft <NUM>, and a first belt <NUM> connecting the first driving motor <NUM> and the first pulley <NUM>. The first driving motor <NUM>, the first shaft <NUM> and the first belt <NUM> in the configuration of the first driving device <NUM> shown in <FIG> may be identical to the first driving motor <NUM>, the first shaft <NUM>, and first belt <NUM> of the first driving device <NUM> shown in <FIG>, respectively.

The first pulley <NUM> of the first driving device <NUM> shown in <FIG> may be provided to cover the second driving motor <NUM>. Specifically, the first pulley <NUM> may include a first base portion 315a extending radially from the first shaft <NUM> at the rear of the second driving motor <NUM>, a first extending portion 315b extending from the first base portion 315a to the drum <NUM>, and a first coupling portion 315c provided at an end of the first extending portion 315b and connected to the first belt <NUM>.

The first extending portion 315b may be inclined to be closer to the drum <NUM> near the outer side in the radial direction of the first pulley <NUM>. However, although not shown, the first extending portion 315b may be provided to extend toward the drum <NUM> by being bent by <NUM> degrees from the first base portion 315a.

According to this configuration, the first belt <NUM> may be connected to the first pulley <NUM> at a position adjacent to the drum <NUM>.

The washing machine shown in <FIG> may secure the internal space of the main body <NUM> by providing the second driving device <NUM> of the driving device <NUM> as a direct driving device and changing the shape of the first pulley <NUM> of the first driving device <NUM>. In addition, the washing machine shown in <FIG> may reduce the number of expensive BLDC motors applied to the driving device <NUM>, thereby reducing the material cost. In addition, although the second driving device <NUM> is shown as a direct driving device in <FIG>, the first driving device <NUM> may be a direct driving device.

<FIG> is a side cross-sectional view illustrating the tub <NUM>, the drum <NUM>, the pulsator <NUM> and a driving device <NUM> of a washing machine according to an exemplary arrangement that is not part of the present invention. <FIG> is a view schematically illustrating a rear surface of the tub <NUM>, drum <NUM>, and driving device <NUM> of the washing machine according to the embodiment shown in <FIG>.

The driving device <NUM> will be described with reference to <FIG> and <FIG>. However, the same components as those in the arrangement shown in <FIG> are denoted by the same reference numerals and description thereof may be omitted.

Referring to <FIG> and <FIG>, the driving device <NUM> includes a first driving device <NUM> and a second driving device <NUM>.

The first driving device <NUM> includes a first driving motor <NUM> that generates a rotational force for rotating the pulsator <NUM>, a first shaft <NUM> extending rearward from the pulsator <NUM> and becoming the rotation axis of the pulsator <NUM>, a first pulley <NUM> coupled to the first shaft <NUM>, a first belt <NUM> that delivers the driving force generated by the first driving motor <NUM> to the first pulley <NUM>, and an idler <NUM> connected to the first belt <NUM>.

The first driving motor <NUM> may be mounted on the lower end of the outer circumferential surface of the tub <NUM>, and may have a first motor shaft 411a. The first belt <NUM> may be connected to the first motor shaft 411a.

The pulsator <NUM> is fixed to one end portion of the first shaft <NUM> and the first pulley <NUM> is fixed to the other end portion.

The first pulley <NUM> may be disposed in the rear of the drum <NUM> and is connected to the first belt <NUM>.

The first belt <NUM> may be connected to the first motor shaft 411a, the first pulley <NUM> and the idler <NUM>, which will be described later, to form the first rotational path P1. The washing machine <NUM> according to the arrangement shown in <FIG> is provided such that the first rotational path P1 formed by the first belt <NUM> and the second rotational path P2 formed by the second belt <NUM> partly overlap each other when viewed from behind the drum <NUM>, but the washing machine according to the embodiment shown in <FIG> and <FIG> is provided such that the first rotational path P1 formed by the first belt <NUM> and the second rotational path P2 formed by the second belt <NUM> do not overlap when viewed from behind the drum <NUM>. Specifically, the washing machine shown in <FIG> and <FIG> may be configured such that the second rotational path P2 formed by the second belt <NUM> is provided inside the first rotational path P1 formed by the first belt <NUM> when viewed from behind the drum <NUM>.

In the case of the washing machine <NUM> according to the arrangement shown in <FIG>, the first belt <NUM> is spaced apart from the second belt <NUM> by a predetermined distance d along the front-rear direction of the drum <NUM>, but the first belt <NUM> or the second belt <NUM> is slipped with respect to the first pulley <NUM> or the second pulley <NUM> as it is driven for a long time, and moved in the forward and back ward directions of the drum <NUM>. In this case, the first belt <NUM> and the second belt <NUM> may interfere with each other in the overlapping portion when viewed from behind the drum <NUM>, which may reduce the reliability of the washing machine <NUM>.

To solve this problem, the washing machine according to the embodiment shown in <FIG> and <FIG> may be configured such that a second rotational path P2 formed by the second belt <NUM> is disposed inside the first rotational path P1 formed by the first belt <NUM> when viewed from behind the drum <NUM>. Accordingly, the washing machine shown in <FIG> and <FIG> may prevent the first belt <NUM> from interfering with the second belt <NUM>.

The idler <NUM> may be provided to be connected to the first belt <NUM>. Specifically, the idler <NUM> may be rotatably provided on an idler shaft 419a mounted on and fixed to the tub <NUM>. At this time, the idler shaft 419a may be arranged to form a substantially triangular shape together with the first motor shaft 411a and the first shaft <NUM> when viewed from behind the drum <NUM>. Accordingly, when viewed from behind the drum <NUM>, the first rotational path P1 may have a rounded triangular shape.

The second driving device <NUM> includes a second driving motor <NUM> to generate a rotational force to rotate the drum <NUM>, a second shaft <NUM> extending rearward from the drum <NUM> and serving as a rotation axis of the drum <NUM>, a second pulley <NUM> coupled to the second shaft <NUM>, and a second belt <NUM> connecting the second driving motor <NUM> and the second pulley <NUM>.

The second driving motor <NUM> may be mounted on the rear surface of the tub <NUM> and has a second motor shaft 431a. Alternatively, the second driving motor <NUM> may be mounted on the lower end of the outer circumferential surface of the tub <NUM> so that the second rotational path P2 is disposed inside the first rotational path P1. The second belt <NUM> may be connected to the second motor shaft 431a. The second driving motor <NUM> may be smaller in size than the first driving motor <NUM>.

The second shaft <NUM> is fixed to the drum <NUM> at one end portion of the second shaft <NUM> and is fixed to the second pulley <NUM> at the other end portion of the second shaft <NUM>. A hollow may be formed inside the second shaft <NUM>, and the first shaft <NUM> may be rotatably inserted into the hollow.

The second pulley <NUM> may be disposed behind the drum <NUM> and is connected to the second belt <NUM>. The second pulley <NUM> may be smaller in size than the first pulley <NUM>.

The second belt <NUM> may be connected to the second motor shaft 431a and the second pulley <NUM> to form a second rotational path P2. The second rotational path P2 may have an approximately elliptical shape when viewed from behind the drum <NUM>. As described above, the second rotational path P2 may be provided inside the first rotational path P1.

The second belt <NUM> may be provided with a shorter and/or narrower width than the first belt <NUM> is because the second driving motor <NUM> and the second pulley <NUM> are provided at a smaller size than the first driving motor <NUM> and the first pulley <NUM>.

Since the second driving motor <NUM> and the second pulley <NUM> are smaller than the first driving motor <NUM> and the first pulley <NUM>, the washing machine of the embodiment shown in <FIG> and <FIG> may secure an internal space.

<FIG> is a side cross-sectional view illustrating the tub <NUM>, the drum <NUM>, the pulsator <NUM> and a driving device <NUM> of a washing machine according to another embodiment of the claimed invention. <FIG> is a view schematically illustrating a rear surface of the tub <NUM>, the drum <NUM>, and the driving device <NUM> of the washing machine according to the embodiment shown in <FIG>.

The first driving device <NUM> includes a first driving motor <NUM> that generates a rotational force to rotate the pulsator <NUM>, a first shaft <NUM> extending rearward from the pulsator <NUM> and becoming the rotation axis of the pulsator <NUM>, a first pulley <NUM> coupled to the first shaft <NUM>, and a first belt <NUM> that delivers the driving force generated in the first driving motor <NUM> to the first pulley <NUM>.

The first driving motor <NUM> may be mounted on the lower end portion of the outer circumferential surface of the tub <NUM> and may have a first motor shaft 511a. The first belt <NUM> may be connected to the first motor shaft 511a.

The pulsator <NUM> is fixed to one end portion of the first shaft <NUM> and the first pulley <NUM> is fixed to the other end portion of the first shaft <NUM>.

The first pulley <NUM> may be disposed behind the drum <NUM> and is connected to the first belt <NUM>. The first pulley <NUM> may include a first base portion 515a extending in the radial direction of the first pulley <NUM> behind the second driving motor <NUM>, and a first coupling portion 515c extending from the first base portion 515a toward the drum <NUM> to cover the second driving motor <NUM> and to which the first belt <NUM> is coupled. The first coupling portion 515c may extend toward the drum <NUM> by being bent at approximately <NUM> degrees at the radially outer end of the first base portion 515a. The first coupling portion 515c may be inclined to be closer to the drum <NUM> near the radially outer side of the first shaft <NUM>. With this configuration, the first belt <NUM> coupled to the first coupling portion 515c may be rotated on the same rotation plane as the rotation plane formed by the second belt <NUM>. In addition, since the second driving motor <NUM> and the second pulley <NUM> are both disposed inside the first pulley <NUM>, the second belt <NUM> is rotated inside the first pulley <NUM>. Accordingly, the washing machine shown in <FIG> and <FIG> may prevent the first belt <NUM> and the second belt <NUM> from interfering with each other.

In addition, the first pulley <NUM> may include a first extending portion that connects the first base portion 515a and the first coupling portion 515c, like the first pulley <NUM> in the arrangement shown in <FIG>.

The first belt <NUM> is connected to the first motor shaft 511a and the first pulley <NUM> to form a first rotational path P1. At this time, as in the embodiment shown in <FIG> and <FIG>, the washing machine according to the embodiment shown in <FIG> and <FIG> is provided such that the first rotational path P1 formed by the first belt <NUM> and the rotational path P2 formed by the second belt <NUM> do not overlap. Specifically, the washing machine shown in <FIG> and <FIG> may be configured such that the second rotational path P2 formed by the second belt <NUM> is provided inside the first rotational path P1 formed by the first belt <NUM> when viewed from behind the drum <NUM>. Accordingly, the washing machine shown in <FIG> and <FIG> may prevent the first belt <NUM> from interfering with the second belt <NUM>. The first rotational path P1 may have an approximately elliptical shape when viewed from behind the drum <NUM>.

The second driving motor <NUM> may be mounted on the rear surface of the tub <NUM> and has a second motor shaft 531a. Alternatively, the second driving motor <NUM> may be mounted on the lower end portion of the outer circumferential surface of the tub <NUM> so that the second rotational path P2 is disposed inside the first rotational path P1. The second belt <NUM> may be connected to the second motor shaft 531a. The second driving motor <NUM> may be smaller than the first driving motor <NUM>.

The second shaft <NUM> is fixed to the drum <NUM> at one end portion of the second shaft <NUM> and to the second pulley <NUM> at the other end portion of the second shaft <NUM>. A hollow may be formed inside the second shaft <NUM>, and the first shaft <NUM> may be rotatably inserted into the hollow.

The second pulley <NUM> may be disposed behind the drum <NUM> and is connected to the second belt <NUM>. The second pulley <NUM> may be smaller in size than the first pulley <NUM> so as to be disposed inside the first pulley <NUM>.

The second belt <NUM> may be connected to the second motor shaft 531a and the second pulley <NUM> to form a second rotational path P2. The second rotational path P2 may have an approximately elliptical shape when viewed from behind the drum <NUM>. As described above, the second rotational path P2 may be provided inside the first rotational path P1.

The second belt <NUM> may be provided with a shorter and/or narrower width than the first belt <NUM> because the second driving motor <NUM> and the second pulley <NUM> are provided in a smaller size than the first driving motor <NUM> and the first pulley <NUM>.

Claim 1:
A washing machine, comprising:
a main body (<NUM>) having a laundry inlet (10a) on the front portion;
a tub (<NUM>) provided inside the main body (<NUM>) to store water;
a drum (<NUM>) rotatably installed inside the tub (<NUM>);
a pulsator (<NUM>) provided inside the drum (<NUM>) and configured to be rotatable with respect to the drum (<NUM>);
a first driving motor (<NUM>, <NUM>) to provide power to the pulsator (<NUM>);
a second driving motor (<NUM>, <NUM>) to provide power to the drum (<NUM>);
a first shaft (<NUM>, <NUM>) extending from the pulsator (<NUM>) along a rotation axis of the pulsator (<NUM>);
a first pulley (<NUM>, <NUM>) connected to the first shaft (<NUM>, <NUM>);
a first belt (<NUM>, <NUM>) connecting the first driving motor (<NUM>, <NUM>) and the first pulley (<NUM>, <NUM>);
a second shaft (<NUM>, <NUM>) extending from the drum (<NUM>) along a rotation axis of the drum (<NUM>);
a second pulley (<NUM>, <NUM>) connected to the second shaft (<NUM>, <NUM>); and
a second belt (<NUM>, <NUM>) connecting the second driving motor (<NUM>, <NUM>) and the second pulley (<NUM>, <NUM>),
wherein a second rotational path (P2) of the second belt (<NUM>, <NUM>) is located between a first rotational path (P1) of the first belt (<NUM>, <NUM>) and the tub (<NUM>), and
characterised in that the first pulley (<NUM>, <NUM>) is different in size from the second pulley (<NUM>, <NUM>).