JPS6288817A - Thrust slide bearing device - Google Patents

Abstract

PURPOSE:To improve load capacity of a bearing and durability and to reduce the cost by providing a plurality of inclined outside grooves on the outside portion of a sliding surface either in a rotary runner at the shaft end or in a static bearing portion and a plurality of rectilinear inside grooves radially on the inside portion thereof. CONSTITUTION:A thrust bearing device 6 is formed by a discoidal rotary runner 7 mounted on a rotary shaft 2 and a discoidal static bearing portion 8 opposite to the runner, and grooves for sucking and discharging a lubricant are formed on the opposite surface on the rotary runner 7 side. A lot of spiral shallow outside grooves 9 are disposed in the same direction on the outside portion, and a circular groove 11 and a rectilinear inside groove 12 shallower than the circular groove are disposed on the inside. These grooves are formed in such a manner that when the depth of the outside groove 9 is H1, and the depth of the inside groove is H2, H1<H2. Accordingly, lubricating oil is retained on the sliding surface by pumping action of these grooves and centrifugal force both during normal rotation and during reverse rotation, so that the load capacity of a bearing and durability can be improved, and the cost can be reduced.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a thrust slide bearing device that supports a rotating shaft of a rotating machine, etc., and particularly relates to a thrust sliding bearing device that supports a rotating shaft in a stationary bearing portion via a fluid lubricant. This invention relates to a lubricated thrust slide bearing device.

[Background of the invention]

Conventional fluid-lubricated thrust sliding bearing devices have a mechanism that allows sliding bearing action to be performed by hydraulic lubrication even when the rotating shaft rotates in either the forward or reverse direction, as shown in Japanese Patent Publication No. 44-22322, for example. There is something I did. Figure 4 shows the bearing sliding surface of such a thrust sliding bearing device. A spiral outer groove 21 and an inner groove 22 are formed, and when the rotating shaft rotates in the direction of arrow C, lubricant is forced into the outer groove 21 from the outside, and when rotating in the direction of arrow C, lubricant is pushed into the outer groove 21.
By forcing lubricant into the inner groove 22 through the duct 23, hydraulic lubrication of the sliding surface of the bearing is achieved, thereby enabling sliding bearing action in both forward and reverse rotational directions. However, according to this bearing device, during forward and reverse rotation, the groove on one side into which the lubricant is pushed is in a positive pressure state, but the groove in the other side, where the lubricant is not pushed, is in a negative pressure state. Furthermore, cavitation was likely to occur on the bearing sliding surface on the negative pressure side. In particular, the oil used as a lubricant for this type of bearing device has a relatively high air solubility property, so a large amount of fine air bubbles are easily dissolved into the oil. Cavitation occurs repeatedly in the groove where negative pressure is generated in the bearing, and as a result, the performance of the lubricant deteriorates and the load capacity of the bearing decreases.Furthermore, the mechanical impact pressure of cavitation causes damage to the bearing. There was a risk that the sliding surface of the bearing would be eroded or corroded, resulting in wear and damage. Furthermore, the conventional thrust helical bearing device described above requires a relatively large bearing area because the bearing sliding surface is divided into two surfaces, resulting in a large outer diameter of the bearing and a large number of man-hours for machining the bearing. Since such two spiral groove groups are formed, there is a problem in that material costs and manufacturing costs increase.

[Purpose of the invention]

The purpose of the present invention is to solve the problems of the conventional ones in the market, to enable sliding bearings for forward and reverse rotation, to prevent the occurrence of cavitation on the sliding surface of the bearing or in the oil film, and to reduce the load capacity of the bearing. It is an object of the present invention to provide a thrust sliding bearing device that can improve performance and reduce product cost.

[Summary of the invention]

In order to achieve the above object, the present invention includes a rotating runner provided at the end of a rotating shaft, and a stationary bearing part that supports the load of the rotating shaft in the axial direction in cooperation with the rotating runner. Lubricant from an external lubricant supply source is sucked into the outer side of the bearing sliding surface on either one side of the stationary bearing part and the rotating runner from the outside to the inner side of the bearing sliding surface when the rotating runner rotates in the forward direction. A plurality of slanted outer grooves are provided, and an annular lubricant supply groove for supplying lubricant from the inside is provided on the inner side of the sliding surface of the bearing. A plurality of linear inner grooves are arranged radially so that the lubricant flows outward due to the centrifugal force of the rotating runner.

According to the present invention having such a configuration, when the rotary shaft rotates in the forward direction, the rotational force of the rotary runner causes lubrication from an external source to be applied to the outer groove provided on the bearing sliding surface of the rotary runner or the stationary bearing. The lubricant is sucked in and flows inward due to the pumping action (inflow). On the other hand, lubricant flows into the inner end of the bearing sliding surface from the annular lubricant supply groove due to the centrifugal force of the rotating runner (outflow). flow). Also,
When the rotary shaft rotates in reverse, the lubricant flows into the inner groove of the bearing sliding surface due to the centrifugal force of the rotary runner, as in the case of forward rotation. In this case, no pumping action occurs in the outer groove of the bearing sliding surface, so the lubricant does not flow from the outside to the inside, and the pressure in this area is lower than that on the inside, but the inside (inner groove), which is under high pressure, A large amount of lubricant flows outward from the (
(outflow), the entire sliding surface of the bearing can be filled with lubricant to maintain a positive pressure state. Therefore, during either forward or reverse rotation, the entire area of the bearing sliding surface is filled with lubricant and a positive pressure state is maintained, making it possible to prevent cavitation from occurring on the bearing sliding surface.

[Embodiments of the invention]

An embodiment of the present invention will be explained based on FIG. 4 without FIG.

FIG. 1 shows a partial sectional view of a rotating device to which a thrust slide bearing device according to an embodiment of the present invention is applied. In the figure, 1 is a rotor of the rotating device, 2 is a rotating shaft of the rotor 1, and 3 4 is a bearing housing, and 4 is a shaft hole. A journal bearing 5 that supports the radial load of the rotating shaft 2 is fitted into the shaft hole 4.

Reference numeral 6 denotes a thrust sliding bearing device which is a main part of this embodiment. The stationary bearing section 8 is configured to include a disk-shaped stationary bearing section 8 provided so as to support the rotary shaft 2, and this stationary bearing section 8 supports the load of the rotating shaft 2 applied to the rotating runner 7 via a lubricating film. As shown in FIG. 2, the surface of the rotary runner 7 facing the stationary bearing portion 8 (bearing sliding surface) has a large number of shallow spiral outer grooves 9 facing in the same direction on its outer side. When the runner 7 rotates in the forward direction (direction of arrow A), the lubricant 15 around the outer periphery of the runner 7 is transferred to the rotating runner 7.
It is configured to suck into the outer groove 9 by the pumping action of.

On the other hand, inside the one-rotation runner 7, an annular groove 11 is formed outside the insertion hole 10 of the rotary shaft 2 and is concentric with the insertion hole 10. A large number of side grooves 12 are arranged so as to extend radially outward, and in this annular groove 11, a lubricant passage 14 provided in the bearing housing 3 and a shaft hole 4 are provided.
The lubricant 15 is supplied via the lubricant 15.

Reference numeral 13 denotes a lubricating tank in which the outer periphery of the thrust bearing assembly fi6 is filled with lubricant 15. A circulation pipe (not shown) communicating with the lubricant flow path 14 is attached to the lubricating tank 13. The lubricant 15 in the lubricant tank 13 is supplied to the annular groove 11 provided in the rotary runner 7 through the shaft hole 4 and the lubricant flow path 14 .

Next, the operation of this embodiment will be explained.

When the rotating shaft 2 rotates in the forward direction (arrow A direction),
Since the rotary runner 7 also rotates in the same direction, the lubricant 15 in the lubricant tank 13 is sucked into the outer groove 9 of the bearing sliding surface by the rotational force of the rotary runner 7 and flows inward, creating an inflow state. 12, the lubricant filled in the annular lubricant supply groove 11 due to the centrifugal force of the rotary runner 7 flows into the inner groove 1.
2 and flows out radially outward, resulting in an outflow state. The solid line ○ in FIG. 4 indicates the fluid pressure distribution characteristics of the bearing sliding surface during forward rotation when the depths of the outer groove 9 and the inner groove 12 of this embodiment are at the same level. As shown.

When the rotating shaft 2 rotates forward, the lubricant is sucked into the outer groove 9, and the outer groove 9
The fluid pressure of the lubricant increases as it moves toward the inside of the 1. The pressure is highest at the inner end of the outer groove 9 and becomes lower as it moves further inside the bearing sliding surface, but the lubricant is flowing into the inner groove 12 in an outflow state, so a positive pressure state is maintained. , the entire sliding surface of the bearing is filled with lubricant and there is no place where negative pressure is generated. In addition, when the rotating shaft 2 and the rotating runner 7 rotate in the reverse direction in the direction of arrow B, the centrifugal force of the rotating runner 7 causes the inner groove 12 provided inside the rotating runner 7 to be Lubricant flows from the inside to the outside of the sliding surface. On the other hand, due to the reverse rotation of the rotary runner 7, the outer groove 9 also enters an outflow state, whereby the outer groove 9 is unable to suck in external lubricant and becomes in a low pressure state. However, in this case, since a large amount of lubricant is supplied outward from the inner groove 12 of the bearing sliding surface under high pressure, this supply amount and the outflow of lubricant released to the outside from the outer groove 9 By balancing the amounts, the sliding surface of the bearing can be filled with lubricant. That's it.

The flow rate of lubricant supplied from the inner groove 12 to the bearing sliding surface during reverse rotation and the flow rate of lubricant flowing out from the outer groove 9 are determined by the rotation speed of the rotating machine and the depths of the inner groove 12 and outer groove 9. 1
It can be determined based on conditions such as the number of grooves, so if these conditions are set appropriately, the flow rate of lubricant from the inner groove 12 and the amount of lubricant flowing out from the outer groove 9 can be harmonized, and the amount of lubricant flowing out from the bearing sliding surface can be adjusted. The solid line P in Figure 4 shows the fluid pressure distribution characteristics of the sliding surface of the bearing during reverse rotation.As shown by the solid line P, the inner groove The lubricant is sucked in from the lubricant 12, and its pressure increases as it moves toward the outside of the inner groove 12 due to the pumping effect, reaching a maximum pressure at the outer end of the inner groove 12, and moving to a lower pressure outside of this. In this case, the lubricant is not sucked into the outer groove 9 from the outside, so the pressure is low, but as described above, in this example, even during dynamic rotation, the inner groove 9
Is the lubricant being supplied to the outside and filling the entire bearing sliding surface without running out of lubricant?1 The external pressure of the bearing sliding surface is also low but positive.

There is no negative pressure anywhere on the bearing sliding surface.

Therefore, according to this embodiment, no negative pressure is generated on the bearing sliding surface in either case of forward or reverse rotation of the shaft 2 of one rotation, and as a result, cavitation can be prevented from occurring, so that the bearing sliding surface can be prevented from occurring. This prevents erosion and damage to the dynamic surface, and allows the rotating shaft to be supported on the bearing surface with optimal hydraulic lubrication.

Figure 6 shows the fluid pressure distribution characteristics of the bearing sliding surface of the conventional thrust sliding bearing device described above, with the inner diameter and outer diameter of the bearing sliding surface being the same as the bearing sliding surface of this embodiment. The solid line Q in the figure shows the fluid pressure distribution characteristic in the direction of the arrow C of the rotation axis, and the dotted line R shows the fluid pressure distribution characteristic when rotating in the direction of the arrow. As is clear from comparing the fluid pressure distribution characteristics between the conventional example shown in FIG. 6 and the present example shown in FIG. becomes wider. In other words, due to the above fluid pressure distribution characteristics.

In this example, the total fluid pressure of the lubricant present on the shaft sliding surface is greater than in the conventional example, and the bearing load capacity can be increased.

Further, according to the two embodiments, the outer groove and the inner groove are efficiently arranged within the same plane of the bearing sliding surface.

The outer diameter of the bearing can be made smaller, and since the inner groove is formed in a straight radial shape, it can be used as a spiral groove! ] Compared to this, it can be processed in a large capacity and formed in a short time, so material costs and manufacturing costs can be reduced.

In the above embodiment, the depth Hl of the outer groove 9 and the depth Hl of the inner groove 12 provided in the rotary runner 7 are formed at the same level, but the present invention is not limited to this. Depth between the depth Hl of the side gutter 12.

As shown in Figure 3, Hl is deeper than Hl<(Ht<Hl
), and by doing so, the lubricant can more easily enter the inner groove 12 from the lubricant supply groove 11 side, so that the lubrication effect on the bearing sliding surface can be further improved. The dashed line ○' in Figure 4 represents the relationship between Hz and Hl.
< H2 shows the fluid pressure distribution characteristics during forward rotation, and the dashed line P' shows the fluid pressure distribution characteristics during reverse rotation. As is clear from a comparison with the first embodiment, the fluid pressure on the bearing sliding surface can be further increased and the total fluid pressure can be improved compared to the first embodiment, so the bearing load capacity can be further improved. can be done.

In each of the above embodiments, the outer groove and the inner groove for letting out the lubricant were provided on the rotary runner side, but instead of this, an outer groove with a similar structure was provided on the bearing sliding surface side of the static IE bearing section. Even if side grooves and inner grooves are provided, the same effects as in each of the above embodiments can be achieved.

〔Effect of the invention〕

As described above-42, according to the present invention, it is possible to perform sliding bearings in both forward and reverse directions, while also preventing the bearing sliding surface and oil 1.
Since it is possible to prevent cavitation from occurring during operation, the bearing load capacity and durability can be greatly improved, and the entire bearing device can be made smaller, reducing product and manufacturing costs. can be achieved.

[Brief explanation of drawings]

FIG. 1 is a partially omitted sectional view of a rotating device to which one embodiment of the present invention is applied, FIG. 2 is a plan view of a bearing component used in the above embodiment, and FIG. 3 is a diagram showing another embodiment of the present invention. A vertical cross-sectional view of the bearing component used, FIG. 4 is a fluid pressure distribution characteristic diagram showing the fluid pressure distribution state on the bearing sliding surface of each of the above embodiments, and FIG. 5 is a plane showing the component of a conventional thrust bearing device. 6 are fluid pressure distribution characteristic diagrams showing the fluid pressure distribution state on the bearing sliding surface of the above-described conventional thrust bearing device. 2... Rotating shaft, 7... Rotating runner, 8... Stationary bearing portion, 9... Outer groove, 11... Lubricant supply groove, 12
...inner groove. 13... External lubricant supply source (lubricating tank), 15... Lubrication (1 other person) Moga I Figure γ /2 13 /6 Potato 2 Prisoner I Potato 3 Ward Kaya 4 Eye - 4 F1 flight 1 External use only °1 Hosouke Kaihoran 4ft, only 5 eyes

Claims (1)

[Scope of Claims] 1. A rotary runner provided at the end of a rotary shaft, and a stationary bearing section that cooperates with the rotary runner to support the load of the rotary shaft in the axial direction, and the stationary bearing section and the rotary runner, the lubricant from an external lubricant supply source is formed on the outer side of the bearing sliding surface on one side of the bearing sliding surface so as to suck lubricant from an external lubricant supply source from the outside to the inside of the bearing sliding surface when the rotary runner rotates in the forward direction. A plurality of inclined outer grooves are provided, and an annular lubricant supply groove is provided on the inner side of the bearing sliding surface to supply lubricant from inside the bearing sliding surface, and the lubricant supply groove is provided with a ring-shaped lubricant supply groove. A thrust sliding bearing device, characterized in that a plurality of linear inner grooves are arranged radially so that lubricant flows outward due to the centrifugal force of the rotating runner. 2. In claim 1, the depth ratio between the depth H_1 of the outer groove and the depth H_2 of the inner groove is H_
A thrust sliding bearing device where 1<H_2.