JP2003232340A - Thrust bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thrust bearing capable of supporting a thrust load without partial striking between a thrust bearing and a thrust collar even when an axis of a rotating shaft is deviated from an axis of the thrust bearing. <P>SOLUTION: Thrust bearing 2 supports the thrust load applied on the rotating shaft via the thrust collar 3 set to the rotating shaft 1. An inside perimeter pad 21 and an outside perimeter pad 22 are radially arranged in the thrust bearing 2, and each of the pads 21 and 22 are divided into a plurality of ones in the circumferential direction. A taper 23 is formed at the land where a gap between the thrust collars widens at the outside perimeter in the outside perimeter pad 22. In the thrust bearing 2, at the side where a partial striking occurs when the axis of the rotating shaft 1 is deviated, a land 22D where the taper 23 widening at the outside side is formed approaches so as to be parallel to the thrust collar 3, so that the ratio that the outside perimeter pad 22 at the partial striking side supports the thrust load increases to prevent temperature increasing and seizure due to the partial striking. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust bearing, and more particularly to a thrust bearing suitable for application to a rotary shaft of a large turbocharger or turbomachine.

[0002]

2. Description of the Related Art A large axial thrust is generated on a rotary shaft for a large turbomachine. For this reason, the bearing supporting portion is often deformed or tilted. Also, the bearing and housing differ in structure and material between bearings, which causes a difference in thermal expansion between the bearings, which causes a slight inclination of the shaft center of the rotating shaft, resulting in uneven bearing between the thrust bearing and the thrust collar. Produce a hit.

If one-sided contact occurs between the thrust bearing and the thrust collar, the oil film thickness of the pad becomes thin, and there is a risk that the thrust load cannot be supported and a rapid temperature rise or seizure occurs.

[0004]

SUMMARY OF THE INVENTION According to the present invention, even if the axis of the rotary shaft deviates from the axis of the thrust bearing, it is possible to support the thrust load without causing one-sided contact between the thrust bearing and the thrust collar. It is an object of the present invention to provide such a thrust bearing.

[0005]

In order to solve the above-mentioned problems, the present invention provides a thrust bearing for supporting a thrust load acting on a rotary shaft via a thrust collar attached to the rotary shaft. , A plurality of pads divided in the circumferential direction are arranged in a plurality of rows in the radial direction, and the pad arranged on the outer circumferential side in the radial direction has a land portion between the thrust collar and Provided is a thrust bearing having a taper in which a clearance is widened on the outer peripheral side.

In the thrust bearing of the present invention, among the pads which are divided into a plurality of pieces in the circumferential direction and are arranged in a plurality of rows in the radial direction, the pad arranged on the outer peripheral side in the radial direction has a clearance with the thrust collar. Is formed on the land part on the outer peripheral side, so if the axis of the rotating shaft shifts, the land part with the tapered part that widens on the outer peripheral side on the side where one-sided contact occurs is the thrust collar. The outer peripheral pad on the one-side contact side increases the ratio of supporting the thrust load by approaching in parallel with.

In this way, it is possible to increase the rate at which the pad on the outer periphery on the side where one-side contact occurs when the axis of the rotary shaft is displaced supports the thrust load, and prevent temperature rise and seizure due to one-side contact. In the thrust bearing of the present invention, the taper formed on the pad on the outer peripheral side may be formed in a step shape to facilitate processing.

Further, in the thrust bearing according to the present invention, the land portions in the pad rows, which are divided into a plurality of pieces in the circumferential direction and are arranged in a plurality of rows in the radial direction, are arranged with their phases shifted so as not to overlap each other in the circumferential direction. When configured,
Side leakage of the lubricating oil is significantly reduced and the load bearing capacity is greatly improved as compared with the case where the phases are the same, which is preferable.

Further, in the thrust bearing according to the present invention, one or both of the pads in at least one row of the pad rows on the inner peripheral side and the holding members thereof are provided with cavities opening toward the pads on the outer peripheral side. , When the elastic deformation of the pad becomes large and the axis of the rotary shaft is displaced, the pad in the one-side contact direction easily elastically deforms, making it easier to secure an oil film thickness between the pad and the thrust collar. In this case, the ability of the pad to bear the thrust load can be exhibited, which is preferable.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A thrust bearing according to the present invention will be specifically described below based on the illustrated embodiments.

(First Embodiment) First, the thrust bearing according to the first embodiment shown in FIGS. 1 to 4 will be described.
1 to 4, reference numeral 1 is a rotary shaft, and a thrust collar 3 is attached to the rotary shaft 1. A thrust load acting on the rotary shaft 1 is a thrust bearing 2 through the thrust collar 3.
Supported by. The thrust bearing 2 is held by the housing 4. As shown in FIGS. 2 and 3, the thrust bearing 2 includes a plurality of rows in the radial direction (in the present embodiment, the inner peripheral pad 21).
And two rows of outer peripheral pads 22).

As shown in FIG. 3, a taper 23 having a downward slope proportional to the radius is attached to the contact surface of the outer peripheral pad 22 located on the peripheral edge of the pads with the thrust collar 3. In other words, the outer peripheral pad 22 is formed with a taper 23 in which the clearance with the thrust collar 3 becomes wider toward the outer peripheral side. On the other hand, the inner pad 2
1 has a taper portion 21C and a land portion 21D.

As described above, the thrust bearing 2 is composed of two rows of pad groups, that is, the inner peripheral pad 21 and the outer peripheral pad 22, and each outer peripheral pad 22 has a filler port 22A as shown in FIGS. , Lubrication groove 22B, taper portion 22
C, land portion 22D. As shown in FIG. 3, the land portion 22D of the outer peripheral pad 22 has a taper 23 having a downward slope from the inner peripheral side toward the outer peripheral side. Figure 2
In the case of, the oil supply groove 22B has an inner peripheral pad 21 and an outer peripheral pad 2
Although it is configured to serve as oil supply to the 2 as well, the outer peripheral pad 22
The oil supply groove may be a completely different system.

The number of pads 21 and 22 in each row and 1
The size of the sheet and the angle of the taper 23 are selected according to operating conditions. As an example, the starting point of the taper 23 in the land portion of the outer peripheral pad 22 is at a position of ⅔ from the inner peripheral side of the pad 22, and when the diameter of the pad is 250 mm, the clearance at the outermost periphery is about 20 μm to 30 μm. Is appropriate. Further, in this embodiment, the number of pads is 2.
Although the column type has been described, the 3 column type and the 4 column type can be similarly applied as required.

In the thrust bearing according to the first embodiment having the above-mentioned structure, when the shaft center of the rotary shaft 1 is rotating on a horizontal plane, the outer peripheral pad 22 is located between the thrust collar 3 and the inner peripheral pad 21. In comparison, the lubricating oil is likely to escape to the outside due to the wide gap and the taper 23 formed so as to widen the gap on the outer peripheral side. Therefore, the outer peripheral pad 22 hardly contributes to support the thrust load as compared with the inner peripheral pad 21.

However, when the shaft center of the rotary shaft 1 shifts vertically from the horizontal plane, that is, when the shaft is off-centered, the thrust collar 3 and the thrust bearing 2 are no longer parallel to each other, resulting in partial contact. If the outer peripheral pad 22 is not provided, the oil film in the one-side contact direction decreases and the pressure rises to support the thrust load unless the oil film collapses.

When the outer peripheral pad 22 is formed with the taper 23 as in the thrust bearing according to the present embodiment, the outer peripheral pad 22 and the thrust collar 3 approach in parallel in the one-sided contact direction, so that the outer peripheral pad 22 supports the thrust load. The percentage to do increases. As a result, it is possible to support the thrust load while reducing the decrease in the oil film thickness on the one-side contact side. Therefore, since a sufficient oil film thickness can be maintained, it is possible to reduce the risk of rapid temperature rise and seizure.

(Second Embodiment) Next, a thrust bearing according to a second embodiment shown in FIGS. 5 and 6 will be described.
In addition, in the second embodiment, only the characteristic portions as compared with the first embodiment will be described, and the portions having the same structure as the thrust bearing according to the first embodiment are denoted by the same reference numerals as those in the first embodiment. However, duplicated description thereof will be omitted.

As shown in FIGS. 5 and 6, the land portion 22D of the outer peripheral pad 22 of the thrust bearing 2 according to the second embodiment.
Are arranged so as to be thinner stepwise in the radial direction than the land portion 21D of the inner peripheral pad 21. That is, as shown in FIG. 6, in the case of two rows of the outer circumference and the inner circumference, the inner circumference pad 21
The land portion 2 of the outer peripheral pad 22 with respect to the land portion 21D of
The 2D is stepwise lowered by one step, and the gap a with the thrust collar 3 is widened on the outer peripheral side. The other structure is the same as the structure of the thrust bearing according to the first embodiment, and the description thereof will be omitted.

In the thrust bearing of the second embodiment having the above structure, when the rotary shaft 1 is angularly offset, the land portion 22D of the outer peripheral pad 22 in the one-side contact direction is formed.
Since the thrust collar 3 approaches and the thrust load can be supported at this portion, the load capacity against the thrust load is increased and the reduction of the oil film thickness of the inner peripheral pad 21 can be suppressed. In a bearing having pads with three or more steps in the radial direction, the pads may be sequentially formed in a stepwise shape as they move to the outer peripheral side so that the clearance with the thrust collar is widened. In the thrust bearing according to the second embodiment, since the taper formed on the pad has a stepped shape, there is an advantage that the machining is very easy as compared with the case of the first embodiment.

(Third Embodiment) Next, a thrust bearing according to a third embodiment shown in FIGS. 7 to 9 will be described.
In addition, in the third embodiment, only the characteristic portions will be described as compared with the first embodiment, and the portions having the same structure as the thrust bearing according to the first embodiment will be denoted by the same reference numerals as those in the first embodiment. However, duplicated description thereof will be omitted.

As shown in FIGS. 7 to 9, the pads of the thrust bearing according to the third embodiment are arranged in two rows in the radial direction, and the inner peripheral pad 21 and the outer peripheral pad 2 in the adjacent rows are arranged.
The two lands 21D and 22D are arranged with their phases shifted so that they do not overlap in the circumferential direction. That is, as shown in FIG. 7, the land portions 21D and 21 of the inner peripheral pad 21 are
The pads are formed so as to be displaced in the circumferential direction so that the land portion 22D of the outer peripheral pad 22 is located between D.

In a case where a plurality of rows of pads are arranged, when the land portion 21D of the inner peripheral pad 21 and the land portion 22D of the outer peripheral pad 22 are arranged with their phases shifted in the circumferential direction, one pad is laid in the radial direction. It is possible to remarkably reduce the side leakage of the lubricating oil as compared with the case where the phases of the two are the same, that is, the case where the phases of both are the same. As a result, the load carrying capacity can be improved, the temperature of the lubricating oil can be prevented from rising, and the cooling effect can be maintained.

The pad lands of the plurality of pads are formed stepwise in the radial direction as described in the third embodiment so that the distances from the thrust collars gradually increase. Further, in FIG. 7, the inner peripheral pad 21 and the outer peripheral pad 22 have the same number of pads, but the number of pads may be changed so that the land portions of the pads do not overlap each other. In this case, there is an advantage that the pads can be easily arranged.

(Fourth Embodiment) Next, a thrust bearing according to a fourth embodiment shown in FIGS. 10 and 11 will be described. In addition, in the fourth embodiment, only the characteristic portions as compared with the first embodiment will be described, and the portions having the same structure as the thrust bearing according to the first embodiment are denoted by the same reference numerals as those in the first embodiment. However, duplicated description thereof will be omitted.

As shown in FIG. 10, in the thrust bearing according to the fourth embodiment, the pads are arranged in a plurality of rows (two rows in the figure) in the radial direction. A cavity 6 is formed in the holding member 5 of the inner peripheral pad 21. The shape of the cavity 6 may be a U-shaped cutout as shown in FIG. 11 or a wedge shape as shown by a dotted line. In any case, it is effective to form the cavity 6 so as to have an opening in the direction of the outer peripheral pad 22.

Also, the cavity 6 does not have to be a full circumference cavity. Depending on the strength of the holding material 5, the cavities 6 may be formed at intervals, or ribs may be reinforced in the cavities 6. Then, the taper 23 is formed in the pad row adjacent to the pad row having the cavity 6 (it may be stepwise). As shown in FIG. 11, a part of the inner peripheral pad 21 or a part of the holding material 5 is a cavity 6, and the outer peripheral pad 22 has an inner peripheral part such that a gap between the outer peripheral pad 22 and the thrust collar 3 expands in the radial direction. A taper 23 is formed in a state of being lowered by one step from the side pad surface and having a downward slope from the inner peripheral side to the outer peripheral side.

In the thrust bearing according to the fourth embodiment configured as described above, by providing the cavity 6 in a part of the pad or the holding material 5 for the pad, elastic deformation when the pad receives pressure is increased. When the axial center of the rotating shaft 1 is angularly offset, the pad in the one-sided contact direction is efficiently elastically deformed (for example, in the direction of the arrow in FIG. 11) to support the thrust load. The thickness can be secured, and since the adjacent pads exhibit the load capacity, it is possible to prevent the oil film thickness of the pads from becoming too thin.

The present invention has been specifically described above with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made within the scope of the present invention as set forth in the claims of the present application. Needless to say, changes and modifications may be added. For example, in the illustrated embodiment, the system of two rows of the inner peripheral pad and the outer peripheral pad is shown in the radial direction, but three or more rows may be used, and the number of pads divided in the circumferential direction is also shown. Other than the above, an appropriate number may be used.

[0030]

As described above, the present invention is a thrust bearing that supports a thrust load acting on a rotary shaft via a thrust collar attached to the rotary shaft, and the thrust bearing has a circumferential direction. Pads divided into a plurality are arranged in a plurality of rows in the radial direction, and in the pad arranged on the outer peripheral side in the radial direction, a gap between the land and the thrust collar is on the outer peripheral side. Provided is a thrust bearing having a structure in which a taper that widens is formed.

In the thrust bearing of the present invention, among the pads which are divided into a plurality of pieces in the circumferential direction and are arranged in a plurality of rows in the radial direction, the pads arranged on the outer peripheral side in the radial direction have a thrust collar. A taper is formed in the land portion so that the clearance becomes wider on the outer peripheral side. Therefore, when the axis of the rotating shaft is deviated, on the side where the one-side contact occurs, the land portion where the taper portion that widens on the outer peripheral side is formed approaches the parallel to the thrust collar, and the one-side contact side outer peripheral pad is formed. Increases the proportion that supports the thrust load, and can prevent temperature rise and seizure due to one-sided contact.

In the thrust bearing of the present invention, if the taper formed on the pad on the outer peripheral side is formed in a stepped shape, it is easy to process. Further, in the thrust bearing according to the present invention, the land portions in the pad rows, which are divided into a plurality of pieces in the circumferential direction and are arranged in a plurality of rows in the radial direction, are arranged with their phases shifted so as not to overlap each other in the circumferential direction. In this case, the side leakage of the lubricating oil is greatly reduced and the load bearing capacity is greatly improved as compared with the case where the phases of both are the same.

Further, in the thrust bearing according to the present invention, one or both of the pads in at least one row of the pad rows on the inner peripheral side and the holding members thereof are provided with cavities opening toward the pads on the outer peripheral side. In the case of a pad, when the elastic deformation of the pad becomes large and the axis of the rotary shaft is displaced, the pad in the one-way contact direction easily elastically deforms, making it easier to secure an oil film thickness between the pad and the thrust collar. It is possible to exert the thrust load bearing capacity of the pad on the contact side.

[Brief description of drawings]

FIG. 1 is an overall side view showing a configuration of a thrust bearing according to a first embodiment of the present invention.

FIG. 2 is a front view taken along line II-II in FIG.

FIG. 3 is a front view taken along the line III-III in FIG.

FIG. 4 is a front view taken along the line IV-IV in FIG.

FIG. 5 is an overall side view showing the configuration of a thrust bearing according to a second embodiment of the present invention.

6 is a front view taken along line VI-VI in FIG.

FIG. 7 is an overall side view showing the configuration of a thrust bearing according to a third embodiment of the present invention.

8 is a front view taken along the line VIII-VIII in FIG.

9 is a front view taken along the line IX-IX in FIG.

10 is a front view of a thrust bearing according to a fourth embodiment of the present invention, which corresponds to FIG.

11 is a front view taken along line XI-XI of FIG.

[Explanation of symbols]

1 rotation axis 2 Thrust bearing 3 thrust color 4 housing 5 holding member 6 cavities 21 inner pad 21C taper part 21D land section 22 Outside Inner Pad 22A Filling port 22B lubrication groove 22C taper part 22D land section 23 taper

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3G005 EA16 FA30 FA31 GB39 GB59                       GB71                 3J011 AA01 AA20 BA15 BA17 BA18                       CA01 CA04 JA02 KA03 MA02                       MA21

Claims (4)

[Claims] 1. A thrust bearing for supporting a thrust load acting on a rotary shaft via a thrust collar attached to the rotary shaft, wherein the thrust bearing has a plurality of pads divided in a circumferential direction in a radial direction. In the pad arranged in a plurality of rows on the outer peripheral side in the radial direction, a taper is formed on the land portion so that the gap between the pad and the thrust collar is widened on the outer peripheral side. Characteristic thrust bearing. 2. The thrust shaft according to claim 1, wherein the taper is formed stepwise. 3. The thrust according to claim 1, wherein the land portions of the pad rows that are adjacent to each other in the radial direction are arranged with a phase shift so as not to overlap each other in the circumferential direction. bearing. 4. The pad in at least one row of the pad row on the inner peripheral side and one or both of the holding members thereof have a cavity open toward the pad on the outer peripheral side. Thrust bearing described.