JP2010151292A - Tilting-pad bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tilting-pad bearing capable of balancing a moment around the fulcrums of pads applied to the pads by oil film pressure even when a load is large, thus preventing the vibration of the pads and effectively cooling lubricating oil generating heat. <P>SOLUTION: The tilting-pad bearing includes: a housing 12 having a fixation support face 12a arranged leaving an interval from a rotating support face 2 of a rotating shaft 1; and the plurality of oscillation pads 14 each positioned between the rotating support face and the fixation support face and having an oscillation pressure receiving face 14a opposing to the rotating support face and the oscillation fulcrum 14c supported by fixation support face so as to enable oscillation. The oscillation pad 14 includes: a plurality of oil fillers 15a provided on the oscillation pressure receiving face 14a while sandwiching the oscillation fulcrum 14c and dispersed in the rotating direction of the rotating shaft 1; and oiling through-holes 15b each communicated from the oil filler 15a to an oscillation support face 14b. The tilting-pad bearing further includes feed oil pipes 16 mounted to the housing 12 and supplying lubricating oil 3 to the oiling through-holes 15b without inhibiting the oscillation of the oscillation pads 14. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a tilting pad bearing that supports a rotating shaft with a plurality of pads.

  The tilting pad bearing is a journal bearing or a thrust bearing in which a bearing surface is composed of a plurality of swingable pads. Such tilting pad bearings have a wide stable region and are used in high-speed rotating machines such as turbo compressors and gear devices.

  For example, Patent Documents 1 and 2 have already been proposed for the tilting pad bearing described above.

  In Patent Document 1, one member can have two functions of holding the tilting pad and lubricating the bearing surface, and the member can be easily attached to the carrier ring without using a screw. An object of the present invention is to prevent the member from coming off without special post-processing.

  Therefore, in Patent Document 1, as shown in FIG. 4, an attachment hole 52 is provided in the carrier ring 51, a spring pin 53 is provided in the attachment hole 52, and a tip portion thereof protrudes between the tilting pads 54. Type in. Then, since the spring pin 53 has a split groove, the spring pin 53 is elastically deformed in the direction of diameter reduction and pressed against the inner surface of the mounting hole 52 by its restoring elastic force, and is prevented from coming off by a large frictional force due to the pressure contact. The spring pins 53 are positioned between the tilting pads 54 and stop the tilting pads 54 from moving in the circumferential direction. Also, the spring pins 53 receive the lubricating oil supplied to the oil grooves on the outer periphery of the carrier ring 51 in the hollow interior (oil It is supplied to the bearing surface B of the tilting pad 54 through the passage 55).

Patent Document 2 aims to provide a tilting pad type journal bearing that supports a high-speed, high-load rotating shaft and that does not cause lubrication shortage at the end of the oil supply groove and both sides of the bearing surface. To do.
Therefore, in Patent Document 2, as shown in FIG. 5, a plurality of bearing pads 65 arranged along the arc of the journal are arranged independently on the upstream side in the rotation direction of the rotation shaft 61 of the bearing pad 65 at intervals in the width direction. The outer diameter side of the oil supply pipe 64 of the oil supply pipe 64 of the bearing pad 65 and the bearing pad 65 in which the diameter of the hole is made and is formed in the radial direction, the outlet is opened in the bearing surface 63 and the new oil 67 is fed into the bearing surface 63. An oil pocket 66 is formed in the bearing pad 65 in the width direction, and feeds the new oil 67 supplied from the outside through the oil supply passage 64 to each of the oil supply pipes 64.

JP-A-11-182535, “tilting pad journal bearing” Japanese Patent No. 3637187, “Journal Bearing”

An example of a journal bearing among the tilting pad bearings is shown in FIG. In this figure, 81 is a rotating shaft, 82 is a pad, 83 is a pad fulcrum, and 84 is a housing. When the rotating shaft 81 rotates, the pad 82 swings (tilts) with the pad fulcrum 83 as a fulcrum, and a tapered taper gap is formed between the inner surface of the pad 82 and the rotating shaft 81, and is introduced into this gap. A dynamic pressure is generated in the lubricating oil, and the rotary shaft 81 is supported by this dynamic pressure.
However, tilting pad bearings sometimes suffer from problems such as seizure and vibration when the bearing temperature rises at high speeds and high loads.

In order to solve this problem, in Patent Document 1 described above, an oil supply pipe (oil passage 55) is disposed near the sliding surface (bearing surface B of the tilting pad 54) to directly lubricate the sliding surface. The temperature of the lubricating oil entering the sliding surface is lowered to lower the bearing temperature.
Moreover, in patent document 2, low temperature oil is directly supplied to a sliding surface from the oil supply groove provided in the pad (bearing pad 65), and the temperature of the oil which enters into a sliding surface is further reduced.

On the other hand, as shown in FIG. 7, the tilting pad bearing can generate an oil film pressure 85 on all the pads 82 by applying a preload. However, as shown in FIG. 8, when the load increases, the oil film pressure 85 may not be generated on the pad 82 on the anti-load side (upper side in the figure).
Even if the technique of Patent Document 2 is temporarily applied to such a tilting pad bearing in which the oil film pressure 85 does not occur, the moment around the pad fulcrum 83 due to the oil film pressure 85 is not balanced. Therefore, the pad 82 vibrates around the pad fulcrum 83, and the pad rear end indicated by A in FIG. 9 may come into contact with the outer peripheral surface of the rotating shaft 81 to cause seizure.

  The present invention has been developed to solve the above-described problems. That is, the object of the present invention is to balance the moment around the pad fulcrum acting on the pad due to the oil film pressure even when the load is large, thereby preventing vibration of the pad and effectively generating the generated lubricating oil. An object of the present invention is to provide a tilting pad bearing that can be cooled.

According to the present invention, a housing having a fixed support surface spaced from the rotation support surface of the rotating shaft;
A swing support point that is positioned between the rotation support surface and the fixed support surface and is supported by the swing support surface facing the rotation support surface, the swing support surface facing the fixed support surface, and the fixed support surface so as to be swingable. A plurality of swing pads, and
The swing pad has a plurality of oil supply ports provided on a swing pressure receiving surface across the swing support point, and an oil supply through hole communicating from the oil supply port to the swing support surface,
There is further provided a tilting pad bearing provided with an oil supply pipe which is attached to the housing and supplies lubricating oil to the oil supply through hole without obstructing the swing of the swing pad.

According to a first preferred embodiment of the present invention, the tilting pad bearing is a journal bearing,
The rotational support surface is a cylindrical outer surface;
The fixed support surface is a hollow cylindrical inner surface;
Two or more oil filler openings are provided on both sides in the rotational direction of the swing fulcrum.

According to a second preferred embodiment of the present invention, the tilting pad bearing is a thrust bearing,
The rotation support surface is a disc or a hollow disc,
The fixed support surface is a disc or a hollow disc,
Three or more oil filler ports are provided so as to surround the swing fulcrum.

According to the configuration of the present invention described above, the swing pad is provided on the swing pressure receiving surface with the swing fulcrum interposed therebetween and dispersed in the rotation direction of the rotation shaft, and the outer surface on the fixed member side from the fuel fill port And an oil supply through hole that is attached to the housing and supplies lubricating oil to the oil supply through hole without obstructing the swing of the swing pad. Lubricating oil can be supplied to the plurality of oil filler ports.
In addition, since multiple oil supply ports are provided across the swing fulcrum, the pressure distribution of the oil film pressure generated around the oil supply port due to the supply of lubricating oil is almost symmetrical across the swing fulcrum, and the load is large However, the moment around the oscillating fulcrum acting on the oscillating pad due to the oil film pressure can be balanced, thereby preventing the oscillation of the oscillating pad and effectively cooling the generated lubricating oil.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a first embodiment of a tilting pad bearing according to the present invention. In this example, the tilting pad bearing 10 of the present invention is a journal bearing that supports the outer peripheral surface 2 of the rotating shaft 1.

  In FIG. 1, the tilting pad bearing 10 of the present invention includes a housing 12, a plurality of swing pads 14, and an oil supply pipe 16.

  The housing 12 has a fixed support surface 12 a spaced from the rotation support surface 2 of the rotary shaft 1. In this example, the rotation support surface 2 is a cylindrical outer surface (outer peripheral surface 2), and the fixed support surface 12a is a hollow cylindrical inner surface.

  A plurality (five in this example) of swing pads 14 are positioned between the rotation support surface 2 and the fixed support surface 12a. Each swing pad 14 is swingably supported by the swing pressure receiving surface 14a facing the rotation support surface 2, the swing support surface 14b facing the fixed support surface 12a, and the fixed support surface 12a. And a fulcrum 14c.

The swing pressure receiving surface 14 a is formed substantially concentrically with the housing 12, and forms a substantially constant gap with the rotation support surface 2 when the rotary shaft 1 is located at the center of the housing 12. This configuration is not essential, and the gap with the rotation support surface 2 may be wedge-shaped in the rotation direction or the reverse rotation direction.
The swing support surface 14b is an arc surface smaller than the fixed support surface 12a, and can swing freely (tilt) about the swing support point 14c. In this example, the swing fulcrum 14b is a contact point at which the swing support surface 14b and the fixed support surface 12a simply contact each other. However, the present invention is not limited to this, and a pin, a ball, or the like may be provided at the contact position to facilitate swinging.

Further, in this figure, the swing pad 14 has a plurality of oil supply ports 15a and an oil supply through hole 15b. The plurality of oil supply ports 15a are provided on the rocking pressure receiving surface 14a with the rocking fulcrum 14c interposed therebetween. In this example, two oil supply ports 15a are provided on both sides in the rotational direction with the swing fulcrum 14c interposed therebetween. Note that the number of the fuel filler ports 15a may be three or more.
The oil supply through hole 15b communicates from the oil supply port 15a to the swing support surface 14b. In this example, the oil supply through holes 15b are two radial through holes that extend radially outward from the respective oil supply ports 15a. However, the present invention is not limited to this. For example, two or more oil supply ports 15 a may be communicated with each other through one radial through hole and the internal manifold of the swing pad 14.

The oil supply pipe 16 is a hollow pipe that is attached to the housing 12 and extends radially inside the oil supply through hole 15b, and lubricates the oil supply port 15a through the oil supply through hole 15b without obstructing the swing of the swing pad 14. Supply oil.
In this example, there is a gap that allows the swing pad 14 to swing between the oil supply through hole 15b and the oil supply pipe 16, and a small amount of lubricating oil flows backward from this gap. Therefore, an elastic sealing material may be provided between the oil supply through hole 15b and the oil supply pipe 16 in order to suppress this backflow.

An oil supply pipe (not shown) is connected to the outer end of the oil supply pipe 16 attached to the housing 12 so as to supply the lubricating oil 3 set to a predetermined pressure.
In this example, the lubricating oil 3 having the same pressure is supplied to the upstream side and the downstream side in the rotational direction of the swing pad 14, but the pressure may be changed between the upstream side and the downstream side.

  FIG. 2 is an operation explanatory view of the tilting pad bearing of FIG. This figure shows a state in which the downward load acting on the rotating shaft 1 is increased, and the oil film pressure is not generated only on the rotating shaft 1 on the two swing pads 14 on the opposite load side (upper side in the figure). In this state, an oil film pressure 5 indicated by a broken line in the drawing is generated on the three swing pads 14 on the load side (lower side in the figure).

According to the above-described configuration of the present invention, the lubricating oil 3 is supplied from the oil supply pipe 16 to the two or more oil supply ports 15a through the oil supply through holes 15b, so that the two or more oil supply ports 15a sandwich the swing fulcrum 15c. Therefore, the oil film pressure 6 can be generated around the oil supply port 15 a by supplying the lubricating oil 3. The pressure of the lubricating oil 3 to be supplied is preferably equal to the oil film pressure 5 generated only by the rotary shaft 1, but may be lower than the oil film pressure 5 as long as the oil film pressure 6 can be generated.
The swing pad 14 on the opposite load side (upper side in the figure) also swings around the swing fulcrum 14c, so that the pressure distribution of the oil film pressure 6 is almost symmetrical across the swing fulcrum 14c, and even when the load is large, The moments around the oscillating fulcrum acting on the oscillating pad 14 due to the oil film pressure 6 can be balanced, thereby preventing the oscillation of the oscillating pad 14 and effectively cooling the generated lubricating oil.

  FIG. 3 is a second embodiment of the tilting pad bearing according to the present invention. In this example, the tilting pad bearing 10 of the present invention is a thrust bearing that supports the thrust of the rotating shaft 1.

FIG. 3A is a view of the tilting pad bearing 10 (thrust bearing) of the present invention viewed from the axial direction of the rotary shaft 1, and FIG. 3B is a cross-sectional view along BB, FIG. FIG.
3A, 3B, and 3C, the tilting pad bearing 10 of the present invention includes a housing 12, a plurality of swing pads 14, and an oil supply pipe 16, as in the first embodiment.

  In this example, the rotation support surface 2 of the rotating shaft 1 is a donut-shaped hollow disk, but may be a disk. The fixed support surface 12a of the housing 12 is also a donut-shaped hollow disk in this example, but may be a disk.

A plurality (eight in this example) of swing pads 14 are positioned between the rotation support surface 2 of the rotating shaft 1 (in this case, a plane) and the fixed support surface 12a of the housing 12 (in this case, a plane).
Each swing pad 14 is swingably supported by the swing pressure receiving surface 14a facing the rotation support surface 2, the swing support surface 14b facing the fixed support surface 12a, and the fixed support surface 12a. And a fulcrum 14c.
The swing pressure receiving surface 14a and the swing support surface 14b are arcuate in this example, but may be flat. Further, the swing fulcrum 14c is a ball in this example, but may have another configuration (for example, a pin).

3A, 3B, and 3C, the swing pad 14 has a plurality of oil supply openings 15a and an oil supply through hole 15b. The plurality of oil supply ports 15 a are provided on the swing pressure receiving surface 14 a with the swing fulcrum 14 c interposed therebetween, and are dispersed in the rotation direction of the rotary shaft 1. In this example, three oil supply ports 15a are provided so as to surround the swing fulcrum 14c (ball). Note that the number of fuel fillers 15a may be four or more.
Other configurations are the same as those of the first embodiment.

According to the configuration of the present invention described above, the lubricating oil 3 is supplied from the oil supply pipe 16 to the three or more oil supply ports 15a through the oil supply through hole 15b, so that the three or more oil supply ports 15a sandwich the swing fulcrum 15c. Therefore, the oil film pressure 6 can be generated around the oil supply port 15 a by supplying the lubricating oil 3.
Further, since each oscillating pad 14 oscillates around the oscillating fulcrum 14c (ball), the pressure distribution of the oil film pressure 6 is almost symmetrical across the oscillating fulcrum 14c, and even when the load is large, the oil film pressure 6 Thus, the moment around the swing fulcrum acting on the swing pad 14 can be balanced, thereby preventing vibration of the swing pad 14 and effectively cooling the generated lubricating oil.

  In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.

1 is a first embodiment of a tilting pad bearing according to the present invention. FIG. 2 is an operation explanatory diagram of the tilting pad bearing of FIG. 1. FIG. 6 is a second embodiment of a tilting pad bearing according to the present invention. FIG. 10 is an explanatory diagram of a tilting pad bearing of Patent Document 1. 10 is an explanatory diagram of a tilting pad bearing of Patent Document 2. FIG. It is explanatory drawing of the conventional tilting pad bearing. It is operation | movement explanatory drawing of the conventional tilting pad bearing. It is another operation | movement explanatory drawing of the conventional tilting pad bearing. It is explanatory drawing of the problem of the conventional tilting pad bearing.

Explanation of symbols

1 rotation axis, 2 rotation support surface,
3 lubricating oil, 5 oil film pressure, 6 oil film pressure 10 tilting pad bearing,
12 housing, 12a fixed support surface,
14 rocking pad, 14a rocking pressure receiving surface,
14b swing support surface, 14c swing support point (ball),
15a Refueling port, 15b Refueling through hole, 16 Refueling pipe

Claims (3)

A housing having a fixed support surface spaced from the rotation support surface of the rotating shaft;
A swing support point located between the rotation support surface and the fixed support surface and supported by the swing support surface facing the rotation support surface, the swing support surface facing the fixed support surface, and the fixed support surface so as to be swingable. A plurality of swing pads, and
The swing pad has a plurality of oil supply ports provided on a swing pressure receiving surface across the swing support point, and an oil supply through hole communicating from the oil supply port to the swing support surface,
Further, the tilting pad bearing is provided with an oil supply pipe which is attached to the housing and supplies lubricating oil to the oil supply through hole without obstructing the swing of the swing pad. The tilting pad bearing is a journal bearing,
The rotational support surface is a cylindrical outer surface;
The fixed support surface is a hollow cylindrical inner surface;
2. The tilting pad bearing according to claim 1, wherein two or more oil supply ports are provided on both sides in the rotation direction of the swing fulcrum. The tilting pad bearing is a thrust bearing,
The rotation support surface is a disc or a hollow disc,
The fixed support surface is a disc or a hollow disc,
The tilting pad bearing according to claim 1, wherein three or more oil filler ports are provided so as to surround a swing fulcrum.

Images