JP5169954B2 - Tilting pad bearing - Google Patents

Description

  The present invention relates to a tilting pad bearing.

A tilting pad bearing is used as a bearing that stably supports a high-speed rotating body. This tilting pad bearing supports a rotating shaft by a plurality of pads arranged in a tiltable manner around the rotating shaft. Further, this tilting pad bearing rotates by supplying lubricating oil to a substantially enclosed space formed by a pad housing that holds the pad from the back, a pair of seal plates provided at both ends of the pad, and a rotating shaft. An oil film is formed between the rotating shaft and the pad by directly supplying lubricating oil between the oil bath mold and the rotating shaft and the pad, which forms an oil film between the shaft and the pad to ensure lubricity. There is a direct lubrication type to ensure lubricity. The oil bath type has a simple structure and is generally widely used. On the other hand, the direct lubrication type has higher cooling performance than the oil bath type and has the advantage that seizure does not occur on the pad surface. However, in order to ensure a sufficient amount of oil supply to the pad surface, the lubrication method is complicated It will be a thing.
Patent Documents 1 and 2 below disclose examples of direct lubrication type tilting pad bearings.

Japanese Patent No. 3637187 JP 2004-197890 A

  By the way, in an oil bath type tilting pad bearing, it is common to construct an oil supply path in a pad housing that holds the pad from the back and to provide an oil supply hole between the pads. When the same pad housing as that of the oil bath type is directly used for a lubricating bearing type tilting pad bearing, the oil surface resistance increases because the oil supply hole is immersed in the lubricating oil, and it becomes difficult to supply the required amount to the pad surface. Therefore, a separate method for directly supplying oil to the pad surface was required.

  A method in which lubricating oil is directly supplied to the pad surface by a method in which an oil supply hole is provided in the pad surface shown in Patent Document 1 or a nozzle is provided in the pad housing oil supply hole shown in Patent Document 2 to supply oil near the pad surface. Is mentioned. However, in these cases, there is a problem in that each part is small and it is difficult to apply to a small machine having no space for installing an oil supply device, and the number of parts and processing man-hours increase.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to ensure a desired supply amount of lubricating oil to the pad surface with a simple configuration, thereby ensuring a desired lubricating performance.

  In order to achieve the above object, in the present invention, as a first solution, a plurality of bearing pads that are tiltably arranged around a rotating shaft, a pad housing that holds the bearing pads from the back, and the rotation A pair of side plates provided at both ends of the bearing pad in a state where the shaft is inserted through the through hole, and at least one of the side plates discharges the lubricating oil to a position corresponding to the back surface of the bearing pad. A means that an oil drain hole is provided is adopted.

  As the second solving means, a means is adopted in which, in the first solving means, the oil drainage hole is formed in an integrated state with the through hole.

  As the third solution means, the first or second solution means described above is provided with a plurality of oil supply passages for supplying lubricating oil to the bearing pads, and oil discharge holes are provided corresponding to the respective oil supply passages. To do.

  According to the present invention, since the oil drain hole for discharging the lubricating oil to the outside is provided at a position corresponding to the back surface of the bearing pad of the side plate, the oil reservoir for the lubricating oil is not formed in the pad housing oil supply hole. Therefore, according to the present invention, it is possible to secure the desired supply amount of the lubricating oil to the pad surface with a simple configuration, and thus it is possible to ensure the desired lubricating performance.

It is the front view which fractured | ruptured a part of tilting pad bearing which concerns on one Embodiment of this invention. 1 is a cross-sectional view of a main part of a tilting pad bearing according to an embodiment of the present invention and a turbo compressor (rotary machine) equipped with the tilting pad bearing. It is sectional drawing which shows the modification of the tilting pad bearing which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The tilting pad bearing 10 according to the present embodiment supports the rotating shaft 2 of the turbo compressor 1 (rotary machine). The rotary shaft 2 is provided with an air seal 3 and an oil seal 4 inserted in addition to the tilting pad bearing 10, and a speed increasing gear 5 is provided at one end of the rotary shaft 2 (the left end in FIG. 1). An impeller 6 is attached to the other end. In other words, the speed increasing gear 5, the tilting pad bearing 10, the oil seal 4, the air seal 3, and the impeller 6 are mounted on the rotary shaft 2 in this order from the rear end side.
In the following description, terms indicating directions such as a circumferential direction and a radial direction are based on the axial direction of the rotating shaft 2.

  As shown in FIG. 2, the tilting pad bearing 10 has five bearings that are disposed in the center of the two-part structure of the pad housing 11 so as to surround the rotation shaft 2 and to be inclined to each other. Pad 15, pad housing 11 that holds these bearing pads 15 from the back, and rotary shaft 2 at both ends (both ends in the axial direction of rotary shaft 2) in a state where rotary shaft 2 is inserted into each through hole 17, 17. It is comprised from a pair of side plate 16A, 16B provided.

  An annular oil supply groove 18 is provided inside the pad housing 11 so as to surround the bearing pad 15 from the outside. Lubricating oil is supplied to the oil supply groove 18 from the outside through a bearing lubricating oil inlet 19 provided in the pad housing 11, and a plurality of oil supply holes 20 arranged in the circumferential direction are provided around the bearing pad 15. Is supplied with lubricating oil. The oil supply holes 20 are provided so as to be positioned between adjacent bearing pads 15, and the lubricating oil passes through the back surface and the side surface of the bearing pad 15 to the pad surface of the bearing pad 15 (sliding surface with the rotating shaft 2). Supplied.

  As shown in FIG. 2, the side surface of the oil supply groove 18 is covered with one side plate 16 </ b> B, thereby forming a lubricating oil flow path. Further, as shown in FIG. 1, the pad housing 11 and the side plates 16A and 16B are divided into two parts with the rotating shaft 2 interposed therebetween, and are coupled by bolts 21 so as not to be separated from each other.

  The bearing pad 15 has a segment shape obtained by dividing the ring at a predetermined angle in the circumferential direction. As shown in FIG. 2, pivots 25 projecting outward are provided on both side surfaces of the bearing pad 15. Since this pivot 25 is supported by the seating portions 26 of the side plates 16A and 16B on the radial center side, the bearing pad 15 is tiltable (can be tilted).

  Further, as shown in FIG. 1, a hole 27 is formed on the outer peripheral side of the bearing pad 15. The bearing pad 15 is restricted from moving in the circumferential direction of the rotary shaft 2 by inserting the tip of the positioning fixing pin 28 inserted from the radially outer side through the pad housing 11 into the hole 27. .

  Further, in the tilting pad bearing 10, a plurality of radial notches 30 are provided as oil drain holes from the through holes 17 and 17 provided in the side plates 16A and 16B toward the radially outer side. The cutouts 30 are provided in the same number as the oil supply holes 20 on the side plates 16A and 16B, and are provided at positions facing the oil supply holes 20. The front end of the notch 30, that is, the outermost end portion in the radial direction, is located slightly ahead of the back surface of the bearing pad 15. That is, the notch 30 is formed so as to extend to the back surface of the bearing pad 15 in a state of being integrated with the through holes 17 and 17.

  In the tilting pad bearing 10 configured as described above, the lubricating oil supplied to the periphery of the bearing pad 15 through the bearing lubricating oil inlet 19, the oil supply groove 18, and the oil supply hole 20 is transferred to the bearing pad 15, the rotating shaft 2, and the like. To lubricate the bearing pad 15.

  Here, the excess lubricating oil supplied to the back surface of the bearing pad 15, that is, radially outward, passes through each notch 30 (oil drain hole) from the vicinity of the back surface of the bearing pad 15 as shown by the arrows in FIG. It is discharged out of the plates 16A and 16B. That is, according to the tilting pad bearing 10, since the lubricating oil is discharged from the vicinity of the back surface of the bearing pad 15 through the notch 30 (oil drain hole), the back surface of the bearing pad 15 can be formed with a very simple configuration. It is possible to suppress the occurrence of an oil pool in the lubricating oil.

  Further, if the lubricating oil is positively discharged, the mixing loss with respect to the periphery of the bearing pad is reduced. Therefore, since heat generation is suppressed and the temperature of the lubricating oil is lowered, an effect of reducing the supply amount of the lubricating oil can be obtained.

In addition, this invention is not limited to the said embodiment, For example, the following modifications can be considered.
(1) Instead of the notches 30 described above, oil drain holes 32 and 32 as shown in FIG. 3 may be provided in the side plates 16A and 16B. That is, the oil drain holes 32 and 32 are round holes independent of the through holes 17 and 17, and open to the oil holes 20 at the same number as the oil holes 20 and at positions facing the oil holes 20. It is provided as follows. The hole shape of the discharge hole 32 is not limited to a round hole, and may be other shapes, and it is not necessary that all the oil discharge holes 32 and 32 have the same shape.

(2) In the above-described embodiment and modification, the lubricant discharged from each of the notches 30 and 30 or the oil drain holes 32 and 32 is excessively moved to an unnecessary portion (for example, an adjacent speed increasing gear or an oil seal). In order to prevent the oil from flowing out, a guide member for guiding the discharged lubricating oil may be provided outside the side plates 16A and 16B.

(3) In the above-described embodiment and modification, the notches 30, 30 or the oil drain holes 32, 32 are provided in the same manner for both the side plates 16A, 16B, but the side plates 16A, 16B are provided. However, the notches 30 and 30 or the oil drain holes 32 and 32 may be provided in different arrangements (asymmetrically). Moreover, you may provide each notch 30 and 30 or each oil drain hole 32 and 32 only in one side of each side plate 16A, 16B.

  DESCRIPTION OF SYMBOLS 1 ... Turbo compressor, 2 ... Rotary shaft, 5 ... Speed increasing gear, 10 ... Tilting pad bearing, 11 ... Pad housing, 15 ... Bearing pad, 16A ... Side plate, 16B ... Side plate, 17, 17 ... Through-hole , 20 ... Oil supply passage, 30, 30 ... Notch, 32, 32 ... Oil drain hole

Claims (3)

A plurality of bearing pads arranged in a tiltable manner around the rotation axis;
A pad housing for holding the bearing pad from the back;
A pair of side plates provided at both ends of the bearing pad in a state where the rotating shaft is inserted through a through hole;
The tilting pad bearing is characterized in that at least one of the side plates is provided with an oil drain hole for discharging lubricating oil to the outside at a position corresponding to the back surface of the bearing pad.   The tilting pad bearing according to claim 1, wherein the oil drain hole is formed in a state of being integrated with the through hole. The tilting pad bearing according to claim 1 or 2, wherein a plurality of oil supply passages for supplying lubricating oil to the bearing pads are provided, and the oil discharge holes are provided corresponding to the respective oil supply passages.

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