US20060032013A1

US20060032013A1 - Brush assembly of cleaner

Info

Publication number: US20060032013A1
Application number: US11/034,773
Authority: US
Inventors: Young-Gie Kim
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2004-08-13
Filing date: 2005-01-14
Publication date: 2006-02-16
Also published as: KR20060015082A; CN1732836A

Abstract

A brush assembly of a cleaner includes a driving motor mounted at a cleaner main body, for generating a rotary force; a brush rotatably disposed at a suction opening formed at the cleaner main body; and a driving force transfer device installed between the driving motor and the brush, rotating the brush by transferring a rotary force of the driving motor to the brush, and protecting the driving motor by preventing transfer of a load generated at the brush to the driving motor. Accordingly, the driving motor can be continuously rotated even if the brush cannot be rotated by being caught by a stuff or the like, thereby preventing motor damage.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a brush assembly of a cleaner, and particularly, to a brush assembly of a cleaner capable of preventing motor damage by keeping the motor rotating when a brush cannot be rotated by being caught by a stuff or the like.
2. Description of the Background Art
In general, a robot cleaner performs a cleaning operation while moving for itself without manipulation of a user, moves to a charging station if power of a battery is consumed during cleaning, and moves back to a cleaning zone to perform a cleaning operation when the battery charge is completed.
A brush assembly for sweeping up dirt or foreign substances from a floor is installed at a suction opening through which dirt is sucked, of the robot cleaner.
FIG. 1 is a side view showing a brush assembly of a robot cleaner in accordance with the conventional art.
The brush assembly in accordance with the conventional art includes a driving motor 102 for generating a rotary force; a brush 106 rotatably installed at a suction opening of the robot cleaner, for sweeping up dirt and foreign substances from a floor; and a driving force transfer device 120 for transferring a rotary force of the driving motor 102 to the brush 106.
Here, the driving force transfer device 120 includes a driving pulley 108 mounted at a rotary shaft 104 of the driving motor 102; a driven pulley 110 mounted at a rotary shaft 116 of the brush 106; and a belt 112 wound between the driving pulley 108 an the driven pulley 110 to transfer a driving force.
In another embodiment, the driving force transfer device includes a driving gear mounted at the rotary shaft of the driving motor; and a driven gear mounted at the rotary shaft of the brush, and transfers a driving force as the driving gear and the driven gear are engaged with each other.
However, because the brush driving force transfer device in accordance with the conventional art mechanically transfers a rotary force of the driving motor to the brush, a motor overload occurs as the brush cannot be rotated by being caught by a stuff or the like, causing motor damage.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a brush assembly of a cleaner capable of preventing motor damage by normally rotating a driving motor when a brush cannot be rotated by being caught by a stuff or the like.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a brush assembly of a cleaner comprising: a driving motor mounted at a cleaner main body, for generating a rotary force; a brush rotatably disposed at a suction opening formed at the cleaner main body; and a driving force transfer device installed between the driving motor and the brush, rotating the brush by transferring a rotary force of the driving motor to the brush, and protecting the driving motor by preventing transfer of a load generated at the brush to the driving motor.
The driving force transfer device comprises: a first magnet mounted at a rotary shaft of the driving motor; and a second magnet mounted at a rotary shaft of the brush and disposed to face the first magnet so that an attractive force can work between itself and the first magnet.
The attractive force working between the first magnet and the second magnet is set to be smaller than the rotary force of the driving motor.
The driving force transfer device comprises: a magnetic body mounted at a rotary shaft of the motor; and a magnet mounted at a rotary shaft of the brush and disposed to face the magnetic body.
The driving force transfer device comprises: a magnet mounted at a rotary shaft of the driving motor; and a magnetic body mounted at a rotary shaft of the brush and disposed to face the magnet.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a brush assembly of a robot cleaner provided with a suction opening at the center of a bottom of a cleaner main body, performing a cleaning operation while moving for itself, and automatically charging a battery, comprising: a driving motor mounted at the cleaner main body, for generating a rotary force; a brush rotatably disposed at the suction opening; and a driving force transfer device installed between the driving motor and the brush, rotating the brush by transferring the rotary force of the driving motor to the brush, and preventing transfer of a load generated at the brush to the motor.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a unit of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
In the drawings:
FIG. 1 is a side view showing a brush assembly of a cleaner in accordance with the conventional art;
FIG. 2 is a front view of a cleaner in accordance with one embodiment of the present invention;
FIG. 3 is a rear view of the cleaner in accordance with one embodiment of the present invention;
FIG. 4 is a sectional view of the cleaner in accordance with one embodiment of the present invention;
FIG. 5 is a perspective view of a brush assembly of the cleaner in accordance with one embodiment of the present invention;
FIG. 6 is a side view of the brush assembly of the cleaner in accordance with one embodiment of the present invention; and
FIGS. 7 and 8 are views showing operation of the brush assembly of the cleaner in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
A plurality of embodiments of a brush assembly of a cleaner in accordance with the present invention may exist, and the most embodiment will be described.
FIG. 2 is a side view of a robot cleaner in accordance with one embodiment of the present invention, FIG. 3 is a rear view of the robot cleaner in accordance with one embodiment of the present invention, and FIG. 4 is a sectional view of the robot cleaner in accordance with one embodiment of the present invention.
The robot cleaner in accordance with the present invention includes: a cleaner main body 10; a suction fan 12 mounted in the cleaner main body 10, for generating a suction force of the cleaner; a filter container 16 mounted in front of the suction fan 12 and having therein a filter 14 for collecting dirt or filth sucked by the suction fan 12; a suction opening 20 connected to the filter container 16 through a suction pipe 18 and formed at a lower side of the main body 10 to suck dirt or filth on a floor 30; and a brush assembly 22 rotatably mounted at one side of the suction opening 20, for sweeping up the dirt and filth from the floor 30.
An ultrasonic wave transmitter 24 for transmitting ultrasonic waves when the cleaner main body 10 moves, and an ultrasonic wave receiver 26 for receiving the ultrasonic waves transmitted from the ultrasonic wave transmitter 24 are mounted at the front of the cleaner main body 10 to detect a position of an obstacle.
A charging terminal 28 is mounted at a rear of the cleaner main body 10, and a battery 32 is charged as the charging terminal 28 is connected to a connection terminal 42 installed on a wall 40 of a room. In addition, a light emitting unit 34 for inducing the charging terminal 28 to the connection terminal 42 is installed at the rear of the cleaner main body 10, and a light receiving unit 44 for receiving an optical signal emitted from the light emitting unit 34 is installed on the wall 40 of the room, where the connection terminal 42 is installed.
A pair of driving wheels 38 driven by a motor 36, and auxiliary wheels 48 supporting the cleaner main body 10 and maintaining a horizontal state are mounted at a lower side of the cleaner main body 10.
FIG. 5 is a perspective view of a brush assembly in accordance with one embodiment of the present invention, and FIG. 6 is a side view of the brush assembly in accordance with one embodiment of the present invention.
The brush assembly 22 includes: a driving motor 50 mounted at the main body 10, for generating a rotary force; a brush 52 rotatably disposed at the suction opening 20; and a driving force transfer device 58 installed between a rotary shaft 54 of the driving motor 50 and a rotary shaft 56 of the brush 52 to transfer a rotary force of the driving motor 50 to the brush 52, and protecting the driving motor 50 by preventing a load generated at the brush 52, for example, as the brush 52 is caught by a stuff, from being transferred to the driving motor 50.
The driving force transfer device 58 includes a first magnet 60 mounted at a rotary shaft 54 of the driving motor 50 to be rotated therewith; and a second magnet 62 mounted at a rotary shaft 56 of the brush 52 and disposed to face the first magnet 60, so that an attractive force works between the first magnet 60 and the second magnet 62.
Here, each of the first magnet 60 and the second magnet 62 is formed as a disc shape, and the attractive force working between the first magnet 60 and the second magnet 62 is set to be smaller than a rotary force of the driving motor 50.
And, surfaces of the first magnet 60 and the second magnet 62, which face each other, have opposite polarities, so that an attractive force can work between the first magnet 60 and the second magnet 62. Namely, as one embodiment, if a facing surface of the first magnet 60 has a north (N) pole, a facing surface of the second magnet 62 has a south (S) pole.
In another embodiment, the driving force transfer device includes a magnetic body (not shown) mounted at the rotary shaft 54 of the driving motor 50; and a magnet (not shown) mounted at the rotary shaft 56 of the brush 52 and disposed to face the magnetic body. Therefore, a rotary force of the driving motor 50 is transferred to the brush 52 by an attractive force working between the magnetic body and the magnet. If a load is generated, for example, as the brush 52 is caught by a stuff, a magnetism of the magnet is overcome, and only the magnetic body is rotated, thereby preventing transfer of the load generated at the brush to the driving motor 50.
In still another embodiment of the driving force transfer device, a magnet (not shown) is mounted at the rotary shaft 54 of the driving motor 50, and a magnetic body (not sown) is mounted at the rotary shaft 56 of the brush 52, wherein the magnet and the magnetic body are disposed to face each other.
Operation of the cleaner in accordance with present invention will now be described.
FIGS. 7 and 8 are views showing the operation of the brush assembly of the cleaner in accordance with the present invention.
When a user presses an operation button, power of a battery 32 is transmitted to the suction fan 12, and the suction fan 12 is driven. Then, a suction force is generated by the driving of the suction fan 12, and thus dirt or filth on the floor 30 are sucked to the suction opening 20 and collected in the filter 14 through the suction pipe 18.
At this time, the brush is rotated 52, sweeping up the dirt and filth from the floor into the suction opening 20. Namely, a rotary force of the driving motor 50 is transferred to the brush 52 through the driving force transfer device 58, thereby rotating the brush 52.
The operation of the driving force transfer device 58 will now be described. First, as shown in FIG. 7, when the driving motor 50 is driven, the first magnet 60 mounted at the rotary shaft 54 of the driving motor 50 is rotated, and the second magnet 62 positioned to face the first magnet 60 is rotated by an attractive force working between itself and the first magnet 60, thereby rotating the second brush 52 connected to the second magnet 62.
As shown in FIG. 8, even if the brush 52 cannot be rotated as a stuff 70 or the like is undesirably put between the brush 52 and the suction opening 20 during a cleaning operation, the driving motor 50 is continuously and normally rotated because the rotary force of the driving motor 50 is greater than the attractive force working between the first magnet 60 and the second magnet 62. Accordingly, the driving motor damage due to an overload can be prevented.
In the brush assembly of the cleaner constructed and operated in such a manner, the first magnet and the second magnet are disposed between the driving motor and the brush in a facing manner, and a rotary force of the driving motor is transferred to the brush by an attractive force working between the first magnet and the second magnet, so that the driving motor is normally rotated even if rotation of the brush is stopped as the brush is caught by a stuff or the like. Accordingly, the driving motor can be prevented from being damaged by an overload.
In addition, because the brush is driven only by a force corresponding to an attractive force working between the first magnet and the second magnet, if friction severely occurs between the brush and the floor, the brush stops rotating, thereby preventing floor damage.
As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims.

Claims

1. A brush assembly of a cleaner comprising:

a driving motor mounted at a cleaner main body, for generating a rotary force;

a brush rotatably disposed at a suction opening formed at the cleaner main body; and

a driving force transfer device installed between the driving motor and the brush, rotating the brush by transferring a rotary force of the driving motor to the brush, and protecting the driving motor by preventing transfer of a load generated at the brush to the driving motor.

2. The brush assembly of claim 1, wherein the driving force transfer device comprises:

a first magnet mounted at a rotary shaft of the driving motor; and

a second magnet mounted at a rotary shaft of the brush and disposed to face the first magnet so that an attractive force can work between itself and the first magnet.

3. The brush assembly of claim 2, wherein the attractive force working between the first magnet and the second magnet is set to be smaller than the rotary force of the driving motor.

4. The brush assembly of claim 1, wherein the driving force transfer device comprises:

a magnetic body mounted at a rotary shaft of the motor; and

a magnet mounted at a rotary shaft of the brush and disposed to face the magnetic body.

5. The brush assembly of claim 4, wherein an attractive force working between the magnetic body and the magnet is set to be smaller than the rotary force of the driving motor.

6. The brush assembly of claim 1, wherein the driving force transfer device comprises:

a magnet mounted at a rotary shaft of the driving motor; and

a magnetic body mounted at a rotary shaft of the brush and disposed to face the magnet.

7. A brush assembly of a robot cleaner provided with a suction opening at the center of a bottom of a cleaner main body, performing a cleaning operation while moving for itself, and automatically charging a battery, comprising:

a driving motor mounted at the cleaner main body, for generating a rotary force;

a brush rotatably disposed at the suction opening; and

a driving force transfer device installed between the driving motor and the brush, rotating the brush by transferring the rotary force of the driving motor to the brush, and preventing transfer of a load generated at the brush to the motor.

8. The brush assembly of claim 7, wherein the driving force transfer device comprises:

a first magnet mounted at a rotary shaft of the driving motor; and

9. The brush assembly of claim 8, wherein the attractive force working between the first magnet and the second magnet is set to be smaller than the rotary force of the driving motor.

10. The brush assembly of claim 7, wherein the driving force transfer device comprises:

a magnetic body mounted at a rotary shaft of the motor; and

11. The brush assembly of claim 10, wherein the attractive force working between the magnetic body and the magnet is set to be smaller than the rotary force of the driving motor.

12. The brush assembly of claim 7, the driving force transfer device comprises:

a magnet mounted at a rotary shaft of the driving motor; and