[DESCRIPTION]

[TITLE OF THE INVENTION]

VIBRATION ABSORBING DAMPER FOR A WASHING MACHINE
[RELATED APPLICATIONS]

This application claims priority to Korean Patent Application No. 10-2014-0046452, filed on April 18, 2014 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference.

[BACKGROUND OF THE INVENTION]

1. Field of the Invention

The present invention relates to a vibration absorbing damper for a washing machine, and more specifically, to a vibration absorbing damper for a full automatic washing machine which includes a slider having radial split pieces to provide a damping force in both compression and tensile directions when compressive and tensile loads are applied to the damper, and a lubricant retaining groove formed in the slider to enhance durability of related parts by lubrication of lubricant retained in the groove.

2. Description of the Related Art

As well-known in the art, a full automatic washing machine includes a rectangular housing forming a body of the washing machine, a cylindrical water tank installed in the housing, and a rotating washing tub rotatably mounted in the water tank by a motor. The water tank having the rotating washing tub is supported in the housing in a four-point

supporting manner through vibration absorbing dampers so as to support the rotating washing tub containing laundry to be rotated in a forward or reverse direction. The vibration absorbing damper is mounted between the housing and the water tank to absorb and reduce vibration and shock generated from the rotating washing tub during operation of the washing machine.

Specifically, the vibration absorbing damper, which is installed between an upper plate of the housing and a lower portion of the water tank, absorbs and reduces the vibration and shock generated from the rotating washing tub during washing and dehydration of laundry, as well as plays a role as a suspension mechanism by providing a supporting force to hold and support the water tank in which the rotating washing tub is rotatably mounted by itself.

Various vibration absorbing dampers for a washing machine are proposed in the related art. Among them, a vibration absorbing damper for a washing machine disclosed in Korean Utility Model Registration No. 20-0221988 includes a support bar which is vertically installed in a housing and has a slider mounted thereon, a support bracket configured to fix an upper end of the support bar to an upper plate of the housing, a damper spring mounted on a lower portion of the support bar, and a damper mounting unit which is fixed to the lower end portion of a water tank and houses the damper spring therein, thereby reducing vibration and shock generated from a rotating washing tub of the water tank by a reciprocating motion of the damper spring and frictional force formed between the slider and the support bar.

For example, FIG. 4 illustrates a conventional vibration absorbing damper for a fully automatic washing machine, which includes: a support rod 101 whose opposite ends are connected to the upper plate of a housing (not shown) and the lower end portion of a water tank (not shown), respectively; a support bracket 102 which is coupled to the upper plate of the housing; a slider 103 which is slidably mounted on an outer periphery of the support rod 101; and a spring 105 which is elastically installed between an upper spring seat 103a formed at the lower portion of the slider 103 and a lower spring seat 104 fixed to a lower end portion of the support rod 101.

In the conventional vibration absorbing damper for a washing machine having the above-described configuration, since the lower side of the upper spring seat 103a of the slider 103 is formed in a single body and is configured to directly contact the upper portion of the spring 105, a damping force is generated in the support rod 101 to absorb and reduce the shock or vibration only during a compression operation when the spring 105 is reciprocated, while the damping force is not generated in the support 101 during a tensile operation. In this state, when shock or vibration is applied to the support rod 101, the damping force is lowered and thereby shock or vibration absorbing and reducing effects may be deteriorated.

In order to solve the above-described problem, another conventional vibration absorbing damper for a washing machine is described in Korean Patent Application No. 10-2013-0117177 filed by the present applicant, which includes, as illustrated in FIGS. 5 and 6, a support rod 201 with a

spring 205 mounted thereon, and a slider 203 which is mounted on an outer periphery of the support rod 101. When the vibration absorbing damper is installed in a housing (not shown) of the washing machine, the upper end of the slider 203 contacts a damper mounting unit (not shown) which is fixed to a lower end portion of a water tank (not shown) and houses the spring 205 therein. If the spring 205 is reciprocatingly compressed or expanded, a frictional force is formed between the slider 203 and the support rod 201 in both compression and tensile directions, thereby increasing a damping force and smoothly absorbing vibration or shock. Herein, since a gap "t" is formed between a peripheral flange 208a which is an upper end of a cover cap 208 and a lower flange of the slider 203, noise is continuously generated by the shock applied during the damping operation. Further, since the slider 203 and the support rod 201 are in frictional contact with each other, the durability of the slider 203 is lowered by the increased friction and the life span thereof is decreased.

[SUMMARY OF THE INVENTION]

In consideration of the above-described circumstances, it is an object of the present invention to provide a vibration absorbing damper for a washing machine which has reduced frictional resistance between a slider and a support rod during a reciprocating operation of a spring to improve durability of related parts, and generates a damping force in both compression and tensile direction operations to reduce shock noise while effectively absorbing vibration and shock.

In order to accomplish the above object, there is provided a vibration

absorbing damper for a washing machine which includes a bar-shaped support rod which is installed between an upper plate of a housing and a lower end portion of a water tank having a rotating washing tub, a bracket which is fixed to an upper plate of the housing to hold an upper end of the support rod inserted therein, a slider which is mounted on an outer periphery of the support rod below the bracket, a cover cap in which the slider is inserted, and a spring which is elastically installed between an upper spring seat formed on the cover cap and a lower spring seat fixed to a lower end portion of the support rod, wherein the slider is formed in a cone shape and has radial split pieces which are dividedly formed on a lower end portion thereof at a predetermined angle with reference to a through hole in which the support rod is inserted, and the radial split pieces of the slider are inserted and mounted in the cover cap, the vibration absorbing damper including: a donut-shaped packing which is mounted on an outer periphery of the slider between a peripheral flange thereof and the upper spring seat of the cover cap; and a lubricant retaining groove which is formed on an inner surface of the radial split pieces of the slider in a longitudinal direction thereof, and is filled with lubricant to reduce a contact frictional force with the support rod which is inserted in the through hole.

According to the vibration absorbing damper for a washing machine of the present invention, it is possible to reduce shock noise and function to absorb and disperse vibration and shock by a damping force generated in both compression and tensile direction operations, and improve the durability of related parts by decreasing the contact frictional force between the slider and the support rod during reciprocating operation of the spring.

[BRIEF DESCRIPTION OF THE DRAWINGS]

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an exploded front view of a vibration absorbing damper for a washing machine according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view illustrating major parts of FIG. 1 in an assembled state;

FIG. 3 is a cross-sectional view illustrating a slider according to the embodiment of the present invention;

FIG. 4 is an exploded front view of a vibration absorbing damper for a washing machine in the related art; and

FIGS. 5 and 6 are views of another vibration absorbing damper for a washing machine in the related art, wherein FIG. 6 is a cross-sectional view illustrating major parts of FIG. 5 in an assembled state.

[DETAILED DESCRIPTION OF THE INVENTION]

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 are an exploded front view and a partial enlarged cross-sectional view of a vibration absorbing damper for a washing machine according to an embodiment of the present invention, respectively.

As described above, the full automatic washing machine includes a rectangular housing forming a body of the washing machine, a cylindrical water tank installed in the housing, and a rotating washing tub rotatably mounted in the water tank by a motor. The water tank having the rotating washing tub is supported in the housing by four-point supporting manner through vibration absorbing dampers so as to support the rotating washing tub containing laundry to be rotated in forward or reverse direction.

The vibration absorbing damper for a washing machine according to the embodiment of the present invention includes a bar-shaped support rod 1 which is installed between an upper plate of a housing (not shown) and a lower end portion of a water tank (not shown) having a rotating washing tub (not shown), a bracket 2 which is fixed to an upper plate of the housing to hold an upper end of the support rod 1 inserted therein, a slider 3 which is mounted on an outer periphery of the support rod 1 below the bracket 2, a cover cap 4 in which the slider 3 is inserted, and a spring 6 which is elastically installed between an upper spring seat 4a formed on the cover cap 4 and a lower spring seat 5 fixed to a lower end portion of the support rod 1.

Herein, the slider 3 is formed in a cone shape and has radial split pieces 3a which are dividedly formed on a lower end portion thereof at a predetermined angle with reference to a through hole 7 in which the support rod 1 is inserted. The radial split pieces 3a of the slider 3 are inserted and mounted in the cover cap 4.

In addition, the vibration absorbing damper for a washing machine includes a donut-shaped packing 8 which is mounted on an outer periphery of the slider 3 between a peripheral flange 3b of the slider 3 and the upper spring seat 4a of the cover cap 4, and a lubricant retaining groove 9 which is formed on an inner surface of the radial split pieces 3a of the slider 3 in a longitudinal direction thereof.

When the vibration absorbing damper is installed in the housing of the washing machine, the upper end of the peripheral flange 3b contacts a damper mounting unit (not shown) which is fixed to a lower end portion of the water tank and houses the spring 6 therein. The lubricant retaining groove 9 is filled with lubricant to reduce a contact frictional force with the support rod 1 which is inserted in the through hole 7.

Herein, the donut-shaped packing 8 has a thickness "t" corresponding to a thickness "t" which may be formed between the peripheral flange 3b of the slider 3 and the upper spring seat 4a of the cover cap 4 during contacting with each other.

In addition, the lubricant retaining groove 9 is formed in a plurality of concave spaces which are equiangularly arranged on the inner surface of the radial split pieces 3a of the slider 3 and have a predetermined width in the longitudinal direction thereof. The lubricant retained in the lubricant retaining groove 9 may use a lubricant such as a high density-abrasion resistance type grease.

Meanwhile, the spring 6 is elastically installed around the outer periphery of the support rod 1 to absorb the vibration or shock applied thereto. For this, the upper end of the spring 6 is seated on the upper

spring seat 4a of the cover cap 4 which contacts the peripheral flange 3b of the slider 3 through the packing 8, and the lower end thereof is seated on the lower spring seat 5 which is mounted on the lower end portion of the support rod 1. As described above, the lower end portion of the support rod 1 is fixed to the water tank having the rotating washing tub.

In the vibration absorbing damper for a washing machine according to the embodiment of the present invention, when vibration or shock is generated during the operation of the washing machine, and if an external force is applied to the support rod 1 from the upper side of the slider 3, the radial split pieces 3a of the slider 3 are contracted about the lower end thereof by the applied external force. Therefore, the contracted radial split pieces 3a contact the outer periphery of the support rod 1 to generate frictional force therebetween while the spring 6 is compressed, and thereby effectively absorbing the vibration or external force applied to the support rod 1.

On the other hand, when an external force is applied to the support rod 1 from the lower side of the slider 3 during the operation of the washing machine, the radial split pieces 3a of the slider 3 are contracted by contacting between the outer periphery of the slider 3 and the inner periphery of the cover cap 4 pressed by the spring 6 returning to its original position. Therefore, the contracted radial split pieces 3a contact the outer periphery of the support rod 1 to induce frictional force therebetween while the spring 6 is returned to its original position, and thereby effectively absorbing and reducing the vibration or shock applied to the support rod 1.

In this case, since the packing 8 is installed between the radial split pieces 3a of the slider 3 and the upper spring seat 4a of the cover cap 4, noise or shock generated in a gap between the slider 3 and the cover cap 4 is smoothly absorbed by the packing 8, when the spring 6 is compressed or expanded in both compression and tensile directions, and thereby more effectively reducing the shock noise.

In addition, since the lubricant retaining groove 9 is formed on the inner surface of the radial split pieces 3a of the slider 3 and the lubricant is retained in the lubricant retaining groove 9, it is possible to reduce the contact frictional force between the outer periphery of the support rod 1 and the inner periphery of the slider 3 and enhance the durability of the related parts.

While the present invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the related art that various modifications and variations may be made therein without departing from the scope of the present invention as defined by the appended claims.

WHAT IS CLAIMED IS:

1. A vibration absorbing damper for a washing machine which
includes a bar-shaped support rod which is installed between an upper plate of a housing and a lower end portion of a water tank having a rotating washing tub, a bracket which is fixed to an upper plate of the housing to hold an upper end of the support rod inserted therein, a slider which is mounted on an outer periphery of the support rod below the bracket, a cover cap in which the slider is inserted, and a spring which is elastically installed between an upper spring seat formed on the cover cap and a lower spring seat fixed to a lower end portion of the support rod, wherein the slider is formed in a cone shape and has radial split pieces which are dividedly formed on a lower end portion of the slider at a predetermined angle with reference to a through hole in which the support rod is inserted, and the radial split pieces of the slider are inserted and mounted in the cover cap, the vibration absorbing damper comprising:

a donut-shaped packing which is mounted on an outer periphery of the slider between a peripheral flange of the slider and the upper spring seat of the cover cap; and

a lubricant retaining groove which is formed on an inner surface of the radial split pieces of the slider in a longitudinal direction of the slider and is filled with lubricant to reduce a contact frictional force with the support rod which is inserted in the through hole.

The vibration absorbing damper according to claim 1, wherein the packing has a thickness "t" corresponding to a thickness "t" which is to be formed between the peripheral flange of the slider and the upper spring seat of the cover cap during contacting with each other.

The vibration absorbing damper according to claim 1, wherein the lubricant retaining groove is formed in a plurality of concave spaces which are equiangularly arranged on the inner surface of the radial split pieces of the slider and have a predetermined width in the longitudinal direction of the slider.