JPH10246232A - Bearing housing - Google Patents

Abstract

(57) [Abstract] [Problem] To completely prevent water or foreign matter from entering the bearing housing, extend the life of the bearing, and reduce the amount of oil and fat used.
To provide a bearing housing that can solve environmental problems caused by leakage of oil and fat. The lubricant conduit communicates with the inside of a bearing housing.
A bearing housing having a device connected to the conduit and absorbing pressure fluctuations inside the bearing housing; and a scalable lubricant storage container and / or an elastic lubricant storage container communicating with the inside of the bearing housing. Bearing box.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing mechanism for a rotating shaft bearing, and more particularly to a mechanism for sealing a bearing to prevent leakage of lubricating oil from the inside of a bearing box to the outside of the bearing box due to a temperature change in the bearing box and to the inside of the bearing box. An object of the present invention is to provide a bearing box capable of preventing both foreign matter such as dust, water and air from entering.

[0002]

2. Description of the Related Art Conventionally, as a bearing sealing mechanism, a sealing mechanism as shown in FIG. 6 or FIG. 7 has been employed.
6 and 7, 1 is a rotating body such as a roll, 2 is a rotating shaft such as a roll rotating shaft, 3 is a bearing base, 4 is a bearing,
5 is a bearing housing, 6 is a bearing retainer (rotor side), 7 is a bearing retainer (anti-rotator side), 8a, 8b and 8c are lubricant supply pipes, 9 is a lubricant discharge pipe, 10, 10a and 10b are seals ( : Dust seal), 11, 11a and 11b are seals (: oil seal), 12
Indicates a color.

[0003] That is, as shown in FIG. 6, when the rotating shaft 2 is provided through the bearing housing 5, the purpose is to prevent lubricant leakage on both sides of the bearing 4 and inside the bearing 4. Oil seals 11a and 11b are provided, and dust seals 10a and 10b are provided outside the oil seals 11a and 11b for preventing water from entering from outside the bearing housing 5 to the bearing portion due to foreign matter or rotating body cooling water.
b is provided.

When the rotating shaft 2 does not penetrate the bearing housing 5, as shown in FIG.
Generally, an oil seal 11 and a dust seal 10 are arranged on the side in that order. The lubricant is supplied from the lubricant supply pipes 8a, 8b, 8c at the center of the bearing 4 to the bearing through holes formed in the bearing 4, as shown in FIG. As shown, the lubricant is supplied from the lubricant oil supply pipes 8a and 8b on the non-rotating body side of the bearing 4 or the lubricant oil supply pipe on the rotating body side.

[0005] In many cases, the supplied lubricant is pushed out from the seal portion, and water and foreign substances are discharged from the system by the lubricant. In recent years, an oil-air lubricating oil supply system using a gas-liquid two-layer flow called oil air has been proposed. However, the above-mentioned conventional sealing mechanisms for rotary shaft bearings each have a problem to be solved from an industrial aspect, though they can achieve a sealing effect.

That is, in the case of the general method shown in FIG. 6 and FIG. 7, it is required to fill an elastic material or a porous material in a dense state in order to enhance the sealing performance. Regardless of the material and lubricity of the filler in a very dense state, frictional resistance to the rotating part exists and wear cannot be avoided. For this reason, the life of the sealing material etc. is short,
Abrasion greatly reduces the sealing action and often does not serve as a sealing material.

[0007] Therefore, the density of the filler and the degree of contact with the rotating part must be in an intermediate state, but as a result, there is a problem in sealing. Even if a two-stage seal is used, wear of the seal lip is inevitable over time, and leakage of lubricant from the bearing box, and intrusion of water and foreign matter into the bearing box is avoided. Absent.

Therefore, as shown in FIG. 6 or 7, the lubricant is supplied constantly or intermittently by automatic lubrication from the lubricant supply pipes 8a, 8b, 8c or 8a, 8b to remove water and foreign substances. It is necessary to push it out of the system, and the consumption of lubricant such as grease or oil and oil mist naturally increases. In addition, when the fluctuation range of the ambient temperature around the bearing is large, at high temperature, the metal parts, the lubricant inside the bearing box, and the air in the gap inside the bearing box thermally expand, and in a general oil seal, the inside of the bearing box is Air pressure (atmospheric pressure + 0.03MPa
If the pressure is higher than about), the sealing ability of the seal is exceeded, and the lubricant is discharged from the sealing device to the outside.

As a result, in the case of the prior art, the periphery of the bearing housing is contaminated with oils and fats, which causes environmental problems and increases the cost required for cleaning. Further, in the vicinity of such bearings, service water such as cooling water is often used, and fats and oils are mixed in the waste water, which increases the load of the waste water treatment. Contrary to the above, when the ambient temperature around the bearing decreases, the inside of the bearing box becomes negative pressure due to the shrinkage of the air inside the bearing box, and the air invades. Engulf.

As described above, when the ambient temperature around the bearing fluctuates greatly, it is inevitable that the lubricant is discharged from the sealing device or foreign matter or water enters the sealing device from the outside. On the other hand, in the oil-air lubricating oil supply system described above, since the inside of the bearing is pressurized with air, it is possible to prevent foreign substances and water from entering the bearing box. Also, intrusion of water and foreign matter is achieved.

However, in the oil-air lubricating oil supply system, consumption of fats and oils and consumption of air are unavoidable, which is not preferable from the viewpoint of energy saving in the compressed air supply source. This is even worse.

[0012]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, completely prevents water or foreign matter from entering the bearing housing, prolongs the life of the bearing, and reduces the amount of oil and fat used. It is an object of the present invention to provide a bearing box capable of reducing the number of problems and solving the environmental problems caused by leakage of oil and fat.

[0013]

A first aspect of the present invention is a bearing housing for accommodating a rotating shaft and a bearing for supporting the rotating shaft, a lubricant conduit communicating with the inside of the bearing housing, and a lubricant conduit connected to the conduit. A device for absorbing pressure fluctuations inside the bearing box. According to a second aspect of the present invention, there is provided a bearing box for storing a rotating shaft and a bearing for supporting the rotating shaft, comprising a scalable lubricant storage container and / or a telescopic lubricant storage container communicating with the inside of the bearing box. It is a bearing box characterized by the above.

In the second invention, the container is:
It is preferable that the lubricant in the bearing housing has a volume that is equal to or greater than the increased volume during thermal expansion. Further, in the second invention, when both a lubricant and a gas such as air coexist in the bearing box, the container is provided with a lubricant in the bearing box and a gas coexisting with the lubricant. It is preferable to have a volume equal to or larger than the increased volume at the time of thermal expansion.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The inventor of the present invention has conducted intensive studies to solve the above-mentioned problems of the prior art. The present invention has been found to be able to solve any of the above-mentioned various problems of the prior art by providing a flexible container and absorbing the pressure fluctuation inside the bearing housing.

The structure and operation of the present invention will be described with reference to the drawings. FIG. 1 shows an example of the bearing housing of the present invention. In FIG. 1, reference numerals 13a, 13b and 13c denote lubricant conduits,
a, 14b, and 14c are scalable lubricant storage containers, f indicates a moving direction of the lubricant, and other symbols indicate the same contents as in FIGS.

The bearing housing shown in FIG. 1 has a lubrication conduit penetrating inside and outside the bearing housing into bearing retainers 6, 7 on both sides of the bearing housing 5.
13a, 13b and 13c are provided, and a scalable or telescopic container (hereinafter referred to as a scalable or elastic lubricant container or simply a lubricating lubricant container) communicated with the inside of the bearing housing outside the bearing housing. ) 14a, 14b and 14c are attached, and when the temperature inside the bearing housing rises, as shown in FIG.
The internal volume of the lubricant storage containers 14a, 14b, 14c is increased, and the pressure inside the bearing housing is prevented from rising.

The lubricant containers 14a, 14 shown in FIG.
As b and 14c, containers made of bellows-shaped Teflon thin plates are used, and the internal volume of the containers changes freely according to the pressure fluctuation inside the bearing housing 5. Also,
Examples of the elastic lubricant storage container include a container using rubber or the like as a material described later. In the same bearing box, both the expandable and contractible lubricant storage container and the elastic lubricant storage container are used. May be used.

As a lubricant containing air in the bearing housing 5, grease or oil is generally used.
Thermal expansion due to temperature rise. For example, if the lubricant temperature is 50
When the temperature rises by ℃, it expands to 1.1 to 1.3 times the volume,
A pressure rise corresponding to this volume expansion occurs inside the bearing housing 5, and when the bearing housing is in a sealed state, the pressure rise is 0.05 to
Reaches 0.15MPa.

However, sealing devices such as the oil seals 11a and 11b have different sealing capabilities depending on the configuration and performance of the seals, but generally have a sealing capability only up to about (atmospheric pressure + 0.03 MPa). When the pressure exceeds the pressure, the lubricant and air leak to the outside of the bearing housing 5, and the pressure inside the bearing housing 5 becomes the same pressure as the above-mentioned upper sealable pressure, and the equilibrium state is maintained.

Particularly, in the case of a casting roll of a continuous casting facility or a work roll of a rolling facility in the iron and steel industry, the temperature rise of the lubricating portion at the time of changing the cooling conditions during operation or restarting after stopping the facility reaches a maximum of about 140 ° C. In this case, a large amount of lubricant is discharged from the inside of the bearing housing 5 to the outside. In addition, when the temperature is inevitable during operation, for example, when the equipment is stopped, the lubricant inside the bearing housing 5 shrinks as the temperature decreases.

At this stage, the internal pressure of the bearing housing 5 decreases,
At a high temperature, a negative pressure corresponding to the amount of the lubricant discharged due to volume expansion occurs, and the pressure inside the bearing housing 5 reaches, for example, (atmospheric pressure-0.03 MPa) to (atmospheric pressure-0.2 MPa). In addition,
The negative pressure changes depending on the configuration of the seal, the presence or absence of the lubricant discharge pipe, or the pressure loss of the lubricant discharge pipe.

In this state, the bearing housing 5 is
Foreign matter and moisture are simultaneously taken in together with air, and the lubricant inside the bearing housing 5 is contaminated. It is a well-known fact that a bearing lubricated with a contaminated lubricant has a significantly reduced life as compared to normal operating conditions, and it is necessary to avoid the entry of water and foreign matter from outside the system.

Based on the above-mentioned considerations, in the first invention, in order to eliminate the above-mentioned respiratory action of the bearing housing, the bearing housing has a conduit communicating with the inside of the bearing housing, and a bearing connected to the conduit and having a bearing connected thereto. A device for absorbing pressure fluctuations inside the box was provided. Further, in the second invention, as a device for absorbing a pressure fluctuation inside the bearing box, for example, as shown in FIG.
In addition, the expandable and contractible lubricant storage container and / or the expandable and contractible lubricant storage container 14a, 14b, 14 communicate with the inside of the bearing housing.
c is attached so that the maximum pressure inside the bearing housing when the pressure inside the bearing housing fluctuates is less than the sealing limit pressure of the seals 10a, 10b, 11a, 11b used.

As a result, according to the present invention, when the temperature inside the bearing housing is high, the lubricant for thermal expansion is stored in the expandable and contractible lubricant storage container and the expandable and contractible lubricant storage container.
It has become possible to suppress an increase in pressure inside the bearing housing and prevent leakage of lubricant from a seal portion or the like. Conversely, under the condition of generating a negative pressure when the temperature inside the bearing housing decreases, the lubricant inside the expandable and contractible lubricant storage container and / or the expandable and contractible lubricant storage container 14a, 14b, and 14c becomes the bearing. It is returned to the inside of the box 5, and the inside of the bearing box is suppressed from becoming negative pressure, and it is possible to prevent suction of water, foreign matter, and the like from outside the bearing box in the seal portion and the like.

That is, the expandable and contractible lubricant storage container (or expandable and contractible lubricant storage container) 14a according to the present invention,
The functions of 14b and 14c are as follows and both of them. According to this function, the lubricant inside the bearing housing 5 removes the gap between the seals 10a and 11a of the bearing housing 5 and the collar 12 and the seal 10 at high temperature.
b, 11b to prevent leakage from the gap between the rotating shaft 2 and
In addition, at low temperatures, it is possible to prevent foreign matter such as water and dust and air from entering the bearing box from the gap.

The pressure inside the bearing box can be reduced by providing the bearing box 5 with a container communicating with the inside of the bearing box and making the container expandable / contractible (or expandable / contractible) containers 14a, 14b and 14c. Always near atmospheric pressure and bearing seal 10a,
Since the pressure can be maintained below the sealable pressure of 10b, 11a, and 11b, it is possible to prevent the lubricant from leaking from the above-mentioned gap to the outside of the bearing housing at a high temperature, and to prevent water from flowing into the bearing housing from the gap at a low temperature. Foreign substances such as dust, and air can be prevented from entering.

When the container is formed entirely of fixed members and the internal volume of the container is constant, the pressure fluctuation inside the bearing housing cannot be prevented, and the above-mentioned functions and effects cannot be obtained. ： Lubricant storage container 14a that can be expanded (or contracted)
, 14b, and 14c serve as storage spaces for the air and the lubricant when the temperature of the lubricant containing air is increased and when the lubricant is expanded, and also have a function of holding the lubricant.

In the present invention, the lubricant container 14a,
Lubricant conduits (hereinafter referred to as conduits) 13a, 13b, and 13c communicating between the bearings 14b and 14c and the inside of the bearing housing 5 are also important, and the lubricant containers 14a, 14a, The effects of 14b and 14c decrease. For example, when grease is used as a lubricant, the grease is allowed to flow in a pipe with an inner diameter of φ8 mm and a length of 150 mm under atmospheric pressure conditions, and when extruded, it is (atmospheric pressure +0.01 MPa) or more, and depending on the properties of the grease. Requires a pressure of (atmospheric pressure + 0.03 MPa) or more.

That is, when the pressure loss of the lubricant flowing through the conduits 13a, 13b, 13c is high, the movement of the lubricant to the lubricant storage containers 14a, 14b, 14c is hindered, and the bearing housing 5
Pressure exceeds the sealing limit of the seals 10a, 10b, 11a, 11b, and the lubricant leaks from, for example, the gap between the oil seal 11a and the collar 12 and the gap between the oil seal 11b and the rotary shaft 2 shown in FIG. In addition, air, water and foreign substances are sucked into the bearing box from outside the bearing box.

Therefore, in the present invention, the viscosity of the lubricant, the flow velocity of the lubricant in the conduit, the flow resistance of the lubricant defined by the relationship between the inner diameter of the conduit and the length of the conduit are determined by the seal provided in the bearing housing. Is preferably designed to be less than the sealing limit. The conduits 13a, 13b and 13c used in the present invention are shown in FIG.
The length and inner diameter of the grease can be easily determined by knowing the required pumping pressure (flow resistance) of the grease calculated or experimentally as shown in FIG.

The structure and operation of the present invention have been described with reference to FIG. 1 showing an example of the bearing housing of the present invention. As is clear from the above description, the number of lubricant storage containers and the number of lubricant storage containers The specific configuration of the bearing box of the present invention, such as the material and form of the bearing box, is not limited to FIG. Next, application examples of the present invention will be described.

FIG. 3 shows a scalable lubricant accommodating container provided with a function for preventing lubricant from flowing out due to pressure fluctuations inside the bearing housing, water,
1 shows a lubricant container configured to have a function of preventing foreign matter and air inhalation and a function of sealing. That is, the lubricant container 14 shown in FIG. 3 has a configuration in which the lubricant container surrounds both the end of the rotating shaft 2 and both the bearing 4 and the sliding portion of the rotating shaft 2.

In the case of the bearing box shown in FIG. 4, a seal 20 is provided on the end side of the rotating shaft 2 with respect to the connection portion C between the lubricant housings 14a and 14b which can be expanded and contracted and the inside of the bearing box. The configuration was adopted. The bearing box shown in FIGS. 3 and 4 described above can greatly reduce the pressure loss of the lubricant conduit, and the inner volume of the lubricant container 14 or 14a, 14b is The bearing box has a lubricant leakage preventing effect and a water, foreign matter, and air sucking preventing effect similar to those of the bearing box shown in FIG.

The material of the lubricant container is not particularly limited, and can be selected by selecting the material and thickness of the material.
It is possible to manufacture an expandable and contractible and expandable container. When the ambient temperature around the bearing box exceeds 100 ° C., as in the case of a casting roll of a continuous casting facility in the steel industry, the material is preferably a material having reliability under high-temperature conditions. Use a lubricant container made of a Teflon thin plate shaped like a bellows like the bearing box shown in
Alternatively, it is preferable to use a lubricant storage container in which a thin metal plate is formed into a bellows shape.

On the other hand, as in the case of a work roll of a cold rolling facility in the steel industry, the ambient temperature around the bearing housing is from room temperature to normal temperature.
In the case of about 60 ° C., the lubricant container is made of rubber or resin as a material of the lubricant container, and is formed into a bellows-shaped lubricant container 14 shown in FIG. 5A, or FIGS. 5B and 5C. The lubricant storage container 15 formed in a bag shape shown in FIG. In FIG. 5B, reference numeral 15a denotes a position of the bag surface at a low temperature, 15b denotes a position of the bag surface at a high temperature, and 16 denotes a lubricant container supporting member.

When a material such as rubber is used, the operation and effects of the present invention can be obtained by making the lubricant container expandable and contractable by selecting the material and thickness.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. A bearing box (internal volume: 1 l) shown in FIG. 1 was provided as a bearing box for a rotating shaft of a casting roll of a continuous casting facility, and a bearing life test was performed. The casting speed was 1.8 m / min, and the rotation speed of the roll rotating shaft 2 was 1.7 rpm.

As the lubricant storage containers 14a, 14b, and 14c, containers (internal volume: 0.3 l) formed by forming a thin plate made of Teflon into a bellows shape are used, and the lubricant conduits 13a, 13b, and 13c each have an inner diameter. : Φ12 mm, length: 25 mm conduit was used. The following specifications were used as the bearing 4, the dust seals 10a and 10b, and the oil seals 11a and 11b.

Bearing (4): Model; self-aligning roller bearing, material: SUJ2 lubricant; urea grease (1 l) sealed Dust seal (10a, 10b): Model: 10a DWT 200 × 27.5 × 15, 10b DG 180 × 210 0 × 7, Material: Fluororubber Oil seal (11a, 11b): Model: 11a DRT 200 × 240 × 16, 11b DRT 180 × 210 × 15, Material: Fluororubber The temperature inside the bearing box during this test Fluctuated in the range from room temperature to 150 ° C.

As a result of the life test, the seals 10a, 10b, 11a, 11
The leakage of the lubricant from the gap between the shaft b and the rotating shaft 2 was prevented, and the intrusion of water and foreign matters almost disappeared. As a result, the conventional bearing accident was eliminated, and the bearing life could be extended to 1.5 times or more the conventional method shown in FIG. Furthermore, the amount of oil and fat used can be significantly reduced by preventing the leakage of the lubricant, and the load on the wastewater treatment can be reduced by reducing the oil and fat in the cooling water after use around the bearing.

As described above, in the embodiment, the bearing housing provided with the expandable and contractible lubricant storage container using Teflon has been described. However, as apparent from the operation of the present invention, in the present invention, rubber or the like is used. The object of the present invention can be achieved also when a stretchable lubricant storage container using the above is used.

[0043]

According to the present invention, it becomes possible to completely prevent water or foreign matter from entering the bearing box, which has occurred in the conventional bearing sealing mechanism due to the respiratory action of the bearing due to the change of the ambient temperature. Was able to eliminate the bearing accident caused by this. In addition, the bearing life can be greatly extended.

Further, the use of the bearing box of the present invention eliminates the need for oiling and lubrication, thereby greatly reducing the amount of oil and fat used. The load on the system can be reduced. Furthermore, the surrounding environment is improved by reducing the leakage of oils and fats,
In addition, it became possible to prevent fires and other disasters caused by leaked oils and fats.

Further, the bearing housing of the present invention is a simple device, and can be attached by partially modifying an existing bearing housing or bearing retainer, does not require significant modification, and is industrially valuable. large. In addition, the supply of air used in the oil-air lubricating oil supply system is not required, and there is an effect that the amount of utility such as electric power consumed by an air compressor for supplying air can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a bearing housing of the present invention.

FIG. 2 is an explanatory view showing the operation of a lubricant container.
(a) shows the normal state, and (b) shows the expansion state of the lubricant container when the internal pressure rises.

FIG. 3 is a side view showing an example of the bearing housing of the present invention.

FIG. 4 is a side view showing an example of the bearing housing of the present invention.

FIG. 5 is a side view showing an example of a lubricant container according to the present invention, wherein (a) shows a thin plate type, and (b) and (c) show a bag type.

FIG. 6 is a side view showing a conventional bearing housing.

FIG. 7 is a side view showing a conventional bearing housing.

FIG. 8 is a graph showing a relationship between a length and an inner diameter of a lubricant conduit and a required pressure for feeding a lubricant (flow resistance).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotating body 2 Rotating shaft 3 Bearing base 4 Bearing 5 Bearing box 6 Bearing holding (rotating body side) 7 Bearing holding (anti-rotating body side) 8a, 8b, 8c Lubricant oil supply pipe 9 Lubricant discharge pipe 10, 10a, 10b Seal ( : Dust seal) 11, 11a, 11b Seal (: oil seal) 12 Collar 13a, 13b, 13c Lubricant conduit 14, 14a, 14b, 14c Lubricant storage container 15, 15a, 15b Lubricant storage container 16 Lubricant storage container support Member 20 Seal C Connection between lubricant container and inside of bearing f Movement direction of lubricant

Claims (4)

[Claims] 1. A bearing housing for accommodating a rotating shaft and a bearing for supporting the rotating shaft, a lubricant conduit communicating with the interior of the bearing housing, and a device connected to the conduit for absorbing pressure fluctuations inside the bearing housing. And a bearing box comprising: 2. A bearing housing for accommodating a rotating shaft and a bearing for supporting the rotating shaft, comprising a scalable lubricant housing and / or an extendable lubricant housing communicating with the inside of the bearing housing. Features bearing box. 3. The bearing housing according to claim 2, wherein the container has a volume equal to or greater than a volume increased when the lubricant in the bearing housing expands thermally. 4. The bearing housing according to claim 2, wherein the container has a volume equal to or larger than an increased volume of the lubricant in the bearing housing and a gas coexisting with the lubricant during thermal expansion.