WO2021210732A1

WO2021210732A1 - Robot cleaner

Info

Publication number: WO2021210732A1
Application number: PCT/KR2020/011441
Authority: WO
Inventors: Hwang Kim
Original assignee: Lg Electronics Inc.
Priority date: 2020-04-17
Filing date: 2020-08-27
Publication date: 2021-10-21
Also published as: KR20210128601A; US20230147162A1; TW202139911A; TWI786436B

Abstract

Provided is a robot cleaner including a main body including a suction portion disposed thereon, main wheels for moving the main body, and a side brush assembly disposed on the main body and rotating with a rotation shaft perpendicular to a rotation shaft of the main wheels, wherein the side brush assembly includes a housing for forming an exterior of the side brush assembly, a first force transmitter disposed in the housing and rotating by receiving a driving force, a belt connected to the first force transmitter, a second force transmitter connected to the first force transmitter by the belt to receive a rotational force of the first force transmitter, and a side brush coupled to the second force transmitter.

Description

ROBOT CLEANER

The present disclosure relates to a robot cleaner, and more particularly, to a robot cleaner that does not cause damage to an obstacle or a side brush even when the obstacle is caught on the side brush during travel.

Generally, a vacuum cleaner is an appliance that sucks air containing a foreign substance from outside by driving an air suction apparatus, which is disposed inside a cleaner main body to generate an air suction force, and separates and collects the foreign substance.

The vacuum cleaner performing the above function is classified into a manual vacuum cleaner that is directly manipulated by a user and a robot cleaner that performs cleaning by itself without the user manipulation. A robot cleaner sucks various foreign substances lying on a face to be cleaned while autonomously travelling on the face-to-be cleaned.

Korean Patent Application Publication No. 10-2006-0111788 discloses a technology in which a robot cleaner includes a side brush to clean various faces of a floor during cleaning. According to the prior art, when the side brush hits an obstacle, the obstacle may move closer to a suction portion and may be sucked into the cleaner. However, in the prior art, when the obstacle does not move when the side brush hits the obstacle, the side brush may be caught by the obstacle and may be damaged, or a strong rotation force may be transmitted to the obstacle and the obstacle may be damaged. In particular, when the obstacle corresponds to an electric wire, the electric wire may be cut and a phenomenon such as an electric leakage and the like may occur.

The present disclosure is to solve the problem as described above. The present disclosure is to provide a robot cleaner with improved stability during travel.

In addition, the present disclosure is to provide a robot cleaner in which a rotation of a side brush changes when an obstacle is caught on the side brush, thereby preventing damage of the obstacle or the side brush.

In order to achieve the above objectives, the present disclosure includes a main body including a suction portion disposed thereon, main wheels for moving the main body, and a side brush assembly disposed on the main body and rotating with a rotation shaft perpendicular to a rotation shaft of the main wheels, wherein the rotation of the side brush assembly may change based on whether an obstacle is hit.

In the present embodiment, two transmitters are connected to each other by a belt, so that operation of a side brush assembly may be maintained in a situation in which a change in a rotational force occurs between the two transmitters when the side brush assembly hits an obstacle. In addition, disclosed is a configuration of connecting the two transmitters with each other by the belt having a constant vertical dimension such that the rotational force may be transmitted between the two transmitters again when the side brush assembly returns to a situation of not hitting the obstacle.

The present disclosure provides a robot cleaner including a main body including a suction portion disposed thereon, main wheels for moving the main body, and a side brush assembly disposed on the main body and rotating with a rotation shaft perpendicular to a rotation shaft of the main wheels, wherein the side brush assembly includes a housing for forming an exterior of the side brush assembly, a first force transmitter disposed in the housing and rotating by receiving a driving force, a belt connected to the first force transmitter, a second force transmitter connected to the first force transmitter by the belt to receive a rotational force of the first force transmitter, and a side brush coupled to the second force transmitter.

The present disclosure discloses a structure in which, when slip occurs between the belt and one of the first force transmitter and the second force transmitter, a rotation angular speed of the first force transmitter and a rotation angular speed of the second force transmitter may become different from each other.

Further, the present disclosure discloses a technology capable of providing the rotational force to both the side brush and agitator using one motor assembly. Different rotational speeds may be transmitted to the side brush and the agitator depending on respective coupling schemes and gear ratios.

The second force transmitter includes a pulley to which the belt is coupled, and a rotation shaft to be coupled to a rotation center of the pulley. In this connection, the side brush is rotated at the same rotational angular speed with the rotation shaft.

Because the motor assembly and the first force transmitter are coupled to each other through a plurality of gear-coupling, a rotational speed is changed, but a rotational force is constantly transmitted from the motor assembly to the first force transmitter. However, because the rotational force is transmitted by the belt from the first force transmitter to the second force transmitter, even when a rotation is consistent in the first force transmitter, a rotation of the second force transmitter may change based on circumstances of the second force transmitter. In one example, when a factor that changes the rotation of the second force transmitter is removed after the rotation of the second force transmitter is changed, the rotational force of the first force transmitter is stably transmitted to the second force transmitter again by the belt.

According to the present disclosure, even when the side brush hits an obstacle that is not moved by the side brush, no damage occurs to the side brush or the obstacle, so that the robot cleaner may travel stably.

That is, according to the present disclosure, when a rotational force having a magnitude equal to or greater than a certain magnitude is applied to the side brush, the rotational force of the side brush may be changed such that the side brush no longer hits the obstacle.

FIG. 1 is a view illustrating a bottom face of a robot cleaner according to the present disclosure.

FIG. 2 is a view illustrating main components according to an embodiment.

FIG. 3 is a view illustrating an exploded perspective view in FIG. 2.

FIG. 4 is a view illustrating a cross-section of some of main components in FIG. 2.

FIG. 5 is a view illustrating an operation of a side brush assembly.

Hereinafter, a preferred embodiment of the present disclosure that may specifically realize the above objects will be described with reference to the accompanying drawings.

In this process, a size, a shape, or the like of a component shown in the drawings may be exaggerated for clarity and convenience of the description. In addition, terms specifically defined in consideration of a configuration and an operation of the present disclosure may vary depending on a user or an operator's intention or practice. Definitions of such terms should be made based on the contents throughout this specification.

FIG. 1 is a view illustrating a bottom face of a robot cleaner according to the present disclosure. Hereinafter, a description will be achieved with reference to FIG. 1.

The present disclosure includes a main body 10 for forming an exterior, main wheels 40 arranged on the main body 10 and rotating such that the main body 10 may be moved back and forth or may turn, and a front auxiliary wheel 20 for supporting one side of the main body 10 and assisting the turning of the main body 10 by the main wheels 40.

In this connection, the main wheels 40 are arranged on left and right sides of the main body 10 independently of each other. The main wheels 40 on the left and right sides may be driven independently of each other.

The main body 10 includes a suction portion 14 for sucking a foreign substance and the like. The suction portion 14 may include an agitator 60 disposed on the main body 10 and being brought into contact with a floor face on which cleaning is performed while rotating, a suction hole defined in the main body 10 and capable of sucking the external foreign substance by a suction force generated inside the main body 10, and the like.

In one example, a rear auxiliary wheel 30 may be disposed rearward of the main wheels 40 to support the other side of the main body 10.

The front auxiliary wheel 20 and the rear auxiliary wheel 30 are arranged to be freely rotatable in a horizontal direction with respect to the main body 10. In one example, the front auxiliary wheel 20 and the rear auxiliary wheel 30 are arranged to have a fixed height with respect to the main body 10.

In one example, although the main wheels 40 are not rotatable in the horizontal direction with respect to the main body 10, the main wheels 40 are composed of two wheels on both sides and the wheels on the both sides rotate at different rotational speeds or in different directions, so that the main body 10 may turn left or right.

Especially, unlike the front auxiliary wheel 20, the main wheels 40 have a height varying with respect to the main body 10. The main wheels 40 may be moved to a desired location or rotated in a desired direction by a rotational force of the wheel in a state in which a rotation shaft is disposed substantially parallel to the floor face or a face to be cleaned where the robot cleaner is moved.

A side brush assembly 100 is disposed on one side of the main body 10. In the side brush assembly 100, as a brush rotates, the brush moves an obstacle located away from a bottom of the main body 10 or an obstacle in contact with a wall to be sucked into the suction portion 14. The side brush assembly 100 may be driven together with the suction portion 14 when the robot cleaner is driven.

In the side brush assembly 100, as a driving force for rotating the brush, a suction force generated in the suction portion 14 or a driving force for rotating the main wheels 40 may be used. In one example, the side brush assembly 100 may include a separate motor to generate a separate rotational force.

FIG. 2 is a view illustrating main components according to an embodiment.

In FIG. 2, a motor assembly 200, a gear box 300, and a side brush assembly 100 are represented together.

The motor assembly 200 has a motor therein, so that a rotational force by the motor may be generated.

The motor assembly 200 is coupled to the gear box 300, so that the rotational force generated by the motor assembly 200 is transmitted to the gear box 300. The gear box 300 is coupled to the side brush assembly 100, so that the rotational force of the motor assembly 200 is transmitted to the side brush assembly 100 through the gear box 300.

The side brush assembly 100 includes a housing that forms an exterior of the side brush assembly 100, a first force transmitter 130 disposed on the housing and rotating by receiving a driving force, a belt 150 connected to the first force transmitter 130, a second force transmitter 170 connected to the first force transmitter 130 by the belt 150 to receive a rotational force of the first force transmitter, and a side brush 190 coupled to the second force transmitter 170.

That is, the rotational force transmitted to the side brush assembly 100 is transferred to the side brush 190 through the first force transmitter 130, the belt 150, and the second force transmitter 170.

FIG. 3 is a view illustrating an exploded perspective view in FIG. 2, and FIG. 4 is a view illustrating a cross-section of some of main components in FIG. 2.

Referring to FIGS. 3 and 4 below, the housing forming the exterior of the side brush assembly 100 includes an upper housing 112 disposed on an upper side and a lower housing 114 coupled to a lower side of the upper housing 112. A space may be defined inside by the upper housing 112 and the lower housing 114, and a plurality of components may be arranged in the space.

The first force transmitter 130 is rotatably coupled to the upper housing 112 and the lower housing 114. The first force transmitter 130 has a first coupling groove 134 defined therein to which the belt 150 is coupled. First coupling ribs 136 for preventing the belt 150 from being removed from the first coupling groove 134 are respectively arranged on a top face and a bottom face of the first coupling groove 134. The first coupling ribs 136 may be arranged to protrude from a portion where the first coupling groove 134 is recessed to respectively surround upper and lower ends of the belt 150. Therefore, even when the belt 150 momentarily slips, the belt 150 may be prevented from leaving the first coupling groove 134. The first coupling ribs 136 are entirely arranged along a circumference of the first coupling groove 134.

The second force transmitter 170 is rotatably coupled to the upper housing 112 and the lower housing 114. The second force transmitter 170 has a second coupling groove 174 defined therein to which the belt 150 is coupled. Second coupling ribs 176 are respectively arranged on a top face and a bottom face of the second coupling groove 174 to prevent the belt 150 from being removed from the second coupling groove 174. The second coupling rib 176 may be arranged to protrude from a portion where the second coupling groove 174 is recessed to respectively surround the upper and lower ends of the belt 150. Therefore, even when the belt 150 momentarily slips, the belt 150 may be prevented from leaving the second coupling groove 174. The first coupling ribs 136 are entirely arranged along a circumference of the second coupling groove 174.

The belt 150 may be an endless belt. In addition, the endless belt may have a constant vertical dimension. The endless belt may have an O-shaped section constantly.

Each of the first coupling groove 134 and the second coupling groove 174 may have a circular shape in which a central portion thereof is more recessed than an outer portion thereof so as to be coupled to the circular cross-section of the belt 150. In one example, the coupling groove may be defined such that recessed depths of the central portion and the outer portion thereof are the same.

Each of the first coupling groove 134 and the second coupling groove 174 has a shape in which a groove is not defined in the middle and has a shape of being recessed along the circumference that is kept constant. That is, the first coupling groove 134 and the second coupling groove 174 are defined to maintain a smooth shape without intermittently protruding portions. Therefore, even when the slip occurs on the belt 150 and locations at which the belt 150 is coupled to the first coupling groove 134 and the second coupling groove 174 are changed, a state in which the belt 150 is coupled to the first coupling groove 134 and the second coupling groove 174 may be maintained.

The second force transmitter 170 includes a pulley 172 to which the belt 150 is coupled, and a rotation shaft 180 coupled to a rotation center of the pulley 172. In this connection, the second coupling groove 174 and the second coupling rib 176 are respectively defined in and formed on the pulley 172.

The rotation shaft 180 is coupled to a central portion of the pulley 172, so that when the pulley 172 is rotated, the rotation shaft 180 is rotated together. The rotation shaft 180 is formed such that upper and lower sides thereof have a polygonal shape rather than a circular shape. Therefore, because a central through-hole of the pulley 172 is coupled to the upper side of the rotation shaft 180, the pulley 172 is rotated with the same rotational angular speed as the rotation shaft 180. The central through-hole of the pulley 172 is defined to have the same polygonal shape as the polygonal shape formed at the upper side of the rotation shaft 180, so that the pulley 172 may be coupled to the rotation shaft 180 so as not to be idle.

The side brush 190 is coupled to the lower side of the rotation shaft 180. A through-hole is also defined in a center of the side brush 190 and is coupled to a polygonal portion formed at the lower side of the rotation shaft 180. The through-hole defined in the side brush 190 is also defined in the same polygonal shape as the rotation shaft 180, so that the side brush 190 and the rotation shaft 180 may be rotated at the same rotational angular speed without idling.

The side brush 190 includes a plurality of brushes 194. The brushes 194 may be distributed to be spaced apart from each other and hit a floor portion where the robot cleaner is moving. The brush 194 is made of a material that may be deformed when a force is applied from the outside. Specifically, because the brush 194 is made of a rubber material, so that a deformation of the brush 194, such as bending, may occur when the brush 194 hits an obstacle made of a relatively strong material. In addition, when the brush 194 does not hit the obstacle by moving away from the obstacle, the brush 194 may be restored into an original shape, that is, a straight extended shape.

The side brush assembly 100 includes a reduction gear 116 for reducing a speed of the rotational force transmitted from the gear box 300. The rotational force transmitted to the reduction gear 116 is transmitted to the first force transmitter 130 through another gear 117. The rotational force transmitted from the gear box 300 is transmitted to the first force transmitter 130 through the plurality of gears. Therefore, when a gear of the gear box 300 is rotated, the first force transmitter 130 is always rotated. However, a rotation speed and the like may be changed by a gear ratio.

The motor assembly 200 includes a motor that is rotated by receiving current from the battery. As the motor is rotated, the motor assembly 200 may generate he rotational force.

The gear box 300 is disposed to engage a rotation shaft of the motor disposed in the motor assembly 200. The gear box 300 includes a first cover 304 that forms an exterior of the gear box 300 and a second cover 306 coupled to the first cover 304. When the first cover 304 and the second cover 306 are coupled to each other, a space is defined therebetween, and a plurality of

gears

310 and 320 are arranged to be engaged with each other in the corresponding space. The plurality of

gears

310 and 320 are rotated based on the rotational force supplied from the motor assembly 200. Specifically, the gear 310 disposed at one end of the gear box 300 may be coupled to and rotated together with the rotation shaft of the motor disposed in the motor assembly 200. In addition, a center of the gear 320 disposed at the other end of the gear box 300 is coupled to the reduction gear 116, so that, as the gear 320 is rotated, the reduction gear 116 may be rotated together. The gear 320 may transmit the rotational force to a rotation shaft of the agitator. Therefore, when the gear 320 is rotated, the rotational force may be simultaneously transmitted to the side brush assembly 100 and the agitator 60.

FIG. 5 is a view illustrating an operation of a side brush assembly.

As shown in FIG. 5, the rotational force generated in the motor assembly 200 may be transmitted to both the side brush assembly 100 and the agitator 60. Because the gear box 300 is disposed between the side brush assembly 100 and the agitator 60, the rotational force of the motor assembly 200 may be simultaneously transmitted to the side brush assembly 100 and the agitator 60.

In one example, the agitator 60 is disposed in a horizontal direction in FIG. 5, and the rotation shaft of the agitator 60 is parallel to the direction in which the agitator 60 is disposed. On the other hand, because the rotation shaft of the side brush assembly 100 is in a normal direction of FIG. 5, the rotation shaft for rotating the agitator 60 and the rotation shaft of the side brush assembly 100 are arranged perpendicular to each other. In one example, the rotation shaft of the agitator 60 and the rotation shaft of the motor assembly 200 may be arranged parallel to each other. All of the plurality of gears arranged in the gear box 300 may be rotated with rotation shafts in a direction parallel to the direction of the rotation shaft of the agitator 60.

In one example, the side brush assembly 100 may also be disposed on a left side of the agitator 60, so that the rotational force generated by one motor assembly 200 may be transmitted to the two side brush assemblies 100. Because the agitator 60 is elongated in the main body 10, the agitator 60 may perform a function of transmitting the rotational force to the side brush assembly positioned on the opposite side.

The rotational force generated by the motor assembly 200 is transmitted to the agitator 60 and the side brush assembly 100 through the gear box 300. In this connection, because the gear box 300 is coupled to the agitator 60 and the side brush assembly 100 in different forms, a rotation speed may be transmitted differently. In one example, in the side brush assembly 100, a rotation direction is vertically changed through the reduction gear 116 and the rotation speed may be reduced. The gear 117 coupled with the reduction gear 116 is gear-coupled to the first force transmitter 130. Therefore, when the reduction gear 116 is rotated, the first force transmitter 130 must be rotated together, and when the rotation of the reduction gear 116 is stopped, the rotation of the first force transmitter 130 must also be stopped.

In one example, when the first force transmitter 130 is rotated, as the second force transmitter 170 coupled to the belt 150 is also rotated, the side brush 190 is also rotated to hit the floor or a side face. In this connection, when a relatively large object such as an electric wire is caught on the brush 194, the brush 194 may be deformed. In addition, a situation in which the rotation of the side brush 190 is slowed or stopped may occur.

In this connection, the slip may occur between the belt 150 and the second force transmitter 170, so that the rotation of the first force transmitter 130 may be continued. For example, when the second force transmitter 170 should be constantly rotated while the first force transmitter 130 is rotated, the side brush 190 should be rotated constantly even when the side brush 190 hits any obstacle. When the side brush 190 is continuously rotated even while twisting occurs by the object such as the electric wire, damage may occur to the robot cleaner as well as the side brush 190. Therefore, in the present embodiment, because a situation in which, even though the rotational force is continuously transmitted from the first force transmitter 130, the second force transmitter 170 does not rotate constantly based on the rotational force of the first force transmitter 130 may occur, the side brush may be prevented from being damaged. In the present embodiment, disclosed is a structure in which a rotation angular speed of the first force transmitter and a rotation angular speed of the second force transmitter may be different when the slip occurs between the belt 150 and the first force transmitter 130 or the second force transmitter 170.

In one example, when the brush 194 is out of a moment of hitting the obstacle, the brush 194 may rotate by the rotational force transmitted from the first force transmitter 130 again by the rotational force by the belt 150.

The present disclosure is not limited to the above-described embodiments. As may be seen from the appended claims, the present disclosure is able to be modified by those of ordinary skill in the field to which the present disclosure belongs, and such modifications are within the scope of the present disclosure.

Claims

A robot cleaner comprising:

a main body including a suction portion disposed thereon;

main wheels for moving the main body; and

a side brush assembly disposed on the main body and rotating with a rotation shaft perpendicular to a rotation shaft of the main wheels;

wherein the side brush assembly includes:

a housing for forming an exterior of the side brush assembly;

a first force transmitter disposed in the housing and rotating by receiving a driving force;

a belt connected to the first force transmitter;

a second force transmitter connected to the first force transmitter by the belt to receive a rotational force of the first force transmitter; and

a side brush coupled to the second force transmitter.
The robot cleaner of claim 1, wherein the first force transmitter has a first coupling groove defined therein, wherein the belt is coupled to the first coupling groove.
The robot cleaner of claim 2, wherein first coupling ribs for preventing the belt from being removed from the first coupling groove are respectively arranged on a top face and a bottom face of the first coupling groove.
The robot cleaner of claim 2, wherein the second force transmitter has a second coupling groove defined therein, wherein the belt is coupled to the second coupling groove.
The robot cleaner of claim 4, wherein second coupling ribs for preventing the belt from being removed from the second coupling groove are respectively arranged on a top face and a bottom face of the second coupling groove.
The robot cleaner of claim 4, wherein the belt is an endless belt having an O-shaped section.
The robot cleaner of claim 6, wherein the endless belt has a constant vertical dimension.
The robot cleaner of claim 1, further comprising:

an agitator disposed in the main body; and

a motor assembly for generating a rotational force for rotating the agitator.
The robot cleaner of claim 8, wherein the agitator rotates about a rotation shaft perpendicular to the rotation shaft of the side brush assembly.
The robot cleaner of claim 8, further comprising:

a gear box for simultaneously transmitting the rotational force of the motor assembly to the side brush assembly and the agitator.
The robot cleaner of claim 10, wherein the side brush assembly includes a reduction gear connected to a gear of the gear box, wherein the reduction gear reduces a rotational speed and transmits the reduced rotational speed to the first force transmitter.
The robot cleaner of claim 11, wherein the reduction gear and the first force transmitter are gear-coupled to each other such that the rotational force is transmitted as it is.
The robot cleaner of claim 1, wherein the second force transmitter includes:

a pulley to be coupled with the belt; and

a rotation shaft coupled to a rotation center of the pulley,

wherein the side brush is rotated at the same rotational angular speed with the rotation shaft of the second force transmitter.
The robot cleaner of claim 1, wherein, when slip occurs between the belt and one of the first force transmitter and the second force transmitter, a rotation angular speed of the first force transmitter and a rotation angular speed of the second force transmitter become different from each other.
The robot cleaner of claim 1, wherein the side brush includes a plurality of brushes,

wherein the brush is made of a material deformable when a force is applied from the outside.