JP2010175008A - Bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing capable of stably supporting a rotating shaft over a wide rotation speed region. <P>SOLUTION: The bearing 1 rotatably supporting the rotating shaft 50 includes: a supporting part 3 storing the rotating shaft 50 in an inside thereof; a plurality of bearing pads 4 arranged between the rotating shaft 50 and the supporting part 3; connecting parts 31 connecting the supporting part 3 and the bearing pad 4 and supporting the bearing pad 4 so as to be displaced around an axis extending in parallel to the rotating shaft 50; and pad slits 41 extended along one direction and the other direction in a circumferential direction of the rotating shaft 50 from the connecting parts 31 between the supporting part 3 and the bearing pad 4. A dimension Cr between the supporting part 3 and the bearing pad 4 which is a width dimension of the pad slit 41 is 0.0005 times or more and 0.002 times or less with respect to a radius R of the rotating shaft 50. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bearing, particularly a bearing suitable for use in a rotating machine that requires high stability.

Conventionally, inclined pad type bearings (tilting pad bearings) have been used when high stability is required as a bearing of a rotating body, such as a supercharger bearing.
However, in general, the inclined pad type bearing has a complicated structure as compared with other bearings and the like, and thus is difficult to manufacture and is an expensive bearing.

  On the other hand, an inclined pad type bearing in which a pad shape that can be inclined with one member is formed by performing slitting on one member to form a slit (see, for example, Patent Document 1). ).

  The inclined pad type bearing described in Patent Document 1 functions as a tilting pad bearing because the pad is inclined by the rotation of the rotating shaft.

JP-T 8-500415

  However, the inclined pad type bearing of Patent Document 1 has a problem that the squeeze oil film effect is low and the damping effect is difficult to obtain, and thus the rotating shaft cannot be stably supported.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a bearing that can stably support a rotating shaft over a wide number of rotations.

In order to achieve the above object, the present invention provides the following means.
A bearing according to the present invention is a bearing that rotatably supports a rotating shaft, and includes a support portion that houses the rotating shaft therein, and a plurality of bearing pads that are disposed between the rotating shaft and the support portion. A connecting portion that connects the supporting portion and the bearing pad, and supports the bearing pad so as to be displaceable about an axis extending in parallel with the rotating shaft, and the connecting portion between the supporting portion and the bearing pad. A pad slit portion extending along one direction and the other direction in the circumferential direction of the rotating shaft, and a dimension between the support portion and the bearing pad, which is a width dimension of the pad slit portion, is It is 0.0005 times or more and 0.002 times or less with respect to the radius of the rotating shaft.

  According to the present invention, since the width dimension of the pad slit portion is 0.0005 times or more and 0.002 times or less with respect to the radius of the rotating shaft, the damping effect by the lubricating oil filled in the pad slit portion is Compared to the invention described in Patent Document 1, it becomes larger. In other words, the squeeze oil film effect in the system composed of the bearing pad and its peripheral components is increased.

  In the above invention, it is desirable that a housing slit portion extending along the circumferential direction and extending along the rotation axis is provided inside the support portion.

  According to the present invention, the housing slit portion is formed inside the support portion, and the inside of the support portion is filled with lubricating oil or the like, so that the support portion can also have a damping effect.

  In the said invention, the bearing housing which accommodates the said support part inside, The press part which is arrange | positioned between the said support part and the said bearing housing, and presses the said support part toward the said rotating shaft is provided. It is desirable.

According to this invention, the clearance gap between a rotating shaft and a bearing pad can be adjusted by pressing a support part toward a rotating shaft with a press part. In other words, the gap value can be kept at an appropriate value.
For example, with respect to the diameter of the rotary shaft, a support portion and a bearing pad in which the gap between the rotary shaft and the bearing pad is larger than a predetermined value can be made, and the gap can be adjusted to a predetermined value by the pressing portion. .

  In the said invention, it is desirable to provide the control part which adjusts the magnitude | size of the pressing force by the said press part according to the rotation state of the said rotating shaft.

  According to the present invention, the gap between the rotating shaft and the bearing pad can be maintained at an appropriate value according to the rotation state of the rotating shaft, for example, the number of rotations.

  According to the bearing of the present invention, since the width dimension of the pad slit portion is 0.0005 times or more and 0.002 times or less with respect to the radius of the rotating shaft, a high damping effect due to the squeeze oil film effect can be obtained. The rotation shaft can be stably supported.

It is a sectional view explaining composition of a bearing concerning a 1st embodiment of the present invention. It is sectional drawing explaining the structure of the bearing which concerns on the 2nd Embodiment of this invention. It is sectional drawing explaining another embodiment in the inner ring | wheel part of FIG. It is sectional drawing explaining the structure of the bearing which concerns on the 3rd Embodiment of this invention.

[First Embodiment]
Hereinafter, a bearing according to a first embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a cross-sectional view illustrating the configuration of the bearing according to the present embodiment.
In the present embodiment, the bearing of the present invention is a bearing for a rotating machine that requires high stability, for example, a bearing 1 that is used in a supercharger or the like and rotatably supports a rotating shaft 50, and incorporates a squeeze film damper. The explanation will be applied to a tilting pad bearing.
As shown in FIG. 1, the bearing 1 is provided with an outer ring portion (bearing housing) 2, an inner ring portion (support portion) 3, and three bearing pads 4.

As shown in FIG. 1, the outer ring portion 2 is a cylindrical or annular member that houses the inner ring portion 3 therein. The outer ring portion 2 is provided with three pressing screw portions (pressing portions) 21 movably in the radial direction of the outer ring portion 2.
Specifically, three female screw holes 22 into which the pressing screw portions 21 extending along the radial direction of the outer ring portion 2 are screwed are formed in the outer ring portion 2 at equal intervals.

  In the present embodiment, the description is applied to an example in which three pressing screw portions 21 are provided in the outer ring portion 2, but the number of pressing screw portions 21 is changed according to the number of bearing pads 4. There is no particular limitation.

As shown in FIG. 1, the pressing screw portion 21 is disposed on the outer ring portion 2, and the end portion on the radially inner side is in contact with the outer peripheral surface of the inner ring portion 3.
Specifically, a male screw to be screwed into the female screw hole 22 is formed on the peripheral surface of the pressing screw portion 21 formed in a substantially cylindrical shape. Therefore, by rotating the pressing screw portion 21, the radial arrangement position of the pressing screw portion 21 with respect to the outer ring portion 2 can be changed. In other words, by rotating the pressing screw portion 21, the force for pressing the inner ring portion 3 toward the radially inner side can be adjusted.

As shown in FIG. 1, the inner ring portion 3 is a member that is disposed inside the outer ring portion 2 and is formed in a cylindrical shape or an annular shape, and is a member that is integrally formed with the bearing pad 4.
The inner ring portion 3 is provided with three connection portions 31 that connect to the bearing pad 4 and support the bearing pad 4 so as to be rotatable about an axis extending along the rotation shaft 50.

The connecting portion 31 is a columnar member extending radially inward from the inner peripheral surface of the inner ring portion 3, in other words, toward the bearing pad 4, and is a member formed integrally with the inner ring portion 3 and the bearing pad 4.
A circular recess is formed in a cross-sectional view at a portion where the connection portion 31 and the inner ring portion 3 are connected, so that the bearing pad 4 can be easily rotated.

  As shown in FIG. 1, the bearing pad 4 is disposed between the inner ring portion 3 and the rotation shaft 50 and supports the rotation shaft 50 so as to be rotatable. The bearing pad 4 is a member formed integrally with the inner ring portion 3. is there. The bearing pad 4 is a plate-like member that curves in a radially convex manner, in other words, a plate-like member that extends along the circumferential surface of the rotating shaft 50. Further, the bearing pad 4 is a member formed integrally with the inner ring portion 3 and the connection portion 31.

  In the present embodiment, description will be made by applying to an example in which three bearing pads 4 are arranged at equal intervals in the circumferential direction. However, the number of bearing pads 4 is not limited to three, and may be more than three. However, it may be small and is not particularly limited.

A pad slit portion 41 is provided between the bearing pad 4 and the inner ring portion 3.
The pad slit portion 41 is between the bearing pad 4 and the inner ring portion 3, and from the connection portion 31 to the circumferential direction of the rotating shaft 50, in other words, on the inner circumferential surface of the inner ring portion 3 or the outer circumferential surface of the bearing pad 4. It is a slit-like space extending in the direction along which the interior is filled with lubricating oil.

  The shape of the pad slit portion 41 is a shape that considers the operating range of the bearing pad 4, that is, when the bearing pad 4 rotates, the outer peripheral surface of the bearing pad 4 and the inner peripheral surface of the inner ring portion 3 do not interfere with each other. It is desirable to have a shape.

  The clearance which is the width of the pad slit portion 41, in other words, the radial dimension Cr is preferably formed in the range of 0.0005R to 0.002R, where R is the radius of the rotating shaft 50.

  For example, when the bearing 1 supports the rotating shaft 50 having a diameter in the range of about 20 mm to about 50 mm, the width of the pad slit portion 41 can be exemplified as about 1 mm or less.

  In addition, as a method for forming the pad slit portion 41, in other words, a method for integrally forming the inner ring portion 3, the connection portion 31, and the bearing pad 4, electric discharge machining can be exemplified.

Next, the support of the rotating shaft 50 in the bearing 1 having the above configuration will be described.
When the rotary shaft 50 is rotatably supported by the bearing 1, as shown in FIG. 1, between the rotary shaft 50 and the bearing pad 4, between the rotary shaft 50 and the inner ring portion 3, and in the pad slit portion 41. The inside is filled with lubricating oil.

Further, the space between the circumferential surface of the rotating shaft 50 and the inner circumferential surface of the bearing pad 4 is adjusted to a predetermined distance.
Specifically, the pressing screw portion 21 is rotated to move the pressing screw portion 21 radially inward with respect to the outer ring portion 2. Then, the inner ring portion 3 is pressed (preloaded) radially inward by the pressing screw portion 21, and the inner ring portion 3 is deformed, whereby the interval between the bearing pad 4 and the rotating shaft 50 is reduced, and a predetermined interval is obtained. Adjusted to.

  When the rotating shaft 50 is rotated in the above-described state, the lubricating oil accompanying the rotating shaft 50 flows between the rotating shaft 50 and the bearing pad 4, and pressure is applied between the rotating shaft 50 and the bearing pad 4. appear. The rotation shaft 50 is supported by this pressure, and a predetermined distance between the rotation shaft 50 and the bearing pad 4 is maintained. In other words, an oil film having a predetermined thickness is formed between the rotating shaft 50 and the bearing pad 4.

On the other hand, the bearing pad 4 extends along the rotating shaft 50 under the influence of external force such as the pressure of the lubricating oil flowing between the rotating shaft 50 and the bearing pad 4 and the displacement of the rotating shaft 50. Rotate around the axis.
Therefore, the bearing pad 4 can be passively rotated with respect to a change in the number of rotations of the rotating shaft 50 or a displacement, and an inclination angle with respect to the rotating shaft 50 can be changed.

  The followability of the inclination angle of the bearing pad 4 with respect to changes in the rotational speed of the rotating shaft 50, the mass of the bearing pad 4 itself, the elastic force of the inner ring portion 3, the viscosity of the lubricating oil filled in the pad slit portion 41, etc. Is a parameter.

That is, when the mass of the bearing pad 4 itself becomes light or the elastic force of the inner ring portion 3 becomes low, the followability of the inclination angle in the bearing pad 4 is improved.
On the other hand, the lubricating oil filled in the pad slit portion 41 provides a damping effect with respect to changes in the inclination angle of the bearing pad 4.

  According to the above configuration, the lubrication filled in the pad slit portion 41 is achieved by setting the width dimension Cr of the pad slit portion 41 to 0.0005 times or more and 0.002 times or less with respect to the radius R of the rotating shaft. The damping effect due to oil is greater than that of the invention described in Patent Document 1. In other words, the squeeze oil film effect is increased.

On the other hand, the gap between the rotating shaft 50 and the bearing pad 4 can be adjusted by pressing the inner ring portion 3 toward the rotating shaft 50 by the pressing screw portion 21. In other words, the gap value can be kept at an appropriate value.
For example, the inner ring portion 3 and the bearing pad 4 in which the gap between the rotary shaft 50 and the bearing pad 4 is larger than a predetermined value with respect to the diameter of the rotary shaft 50 are formed, and the gap is made predetermined by the pressing screw portion 21. Can be adjusted to the value.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
The basic configuration of the bearing of this embodiment is the same as that of the first embodiment, but the configuration of the inner ring portion is different from that of the first embodiment. Therefore, in the present embodiment, only the configuration of the inner ring portion will be described using FIG. 2 and FIG.
FIG. 2 is a cross-sectional view illustrating the configuration of the bearing according to the present embodiment.
In addition, about the component same as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 2, the bearing 101 is provided with an outer ring portion 2, an inner ring portion (support portion) 103, and three bearing pads 4.

As shown in FIG. 2, the inner ring portion 103 is a member that is disposed inside the outer ring portion 2 and is formed in a cylindrical shape or an annular shape, and is a member that is integrally formed with the bearing pad 4.
The inner ring portion 103 is provided with three connection portions 31 and an inner ring slit portion (housing slit portion) 132.

The inner ring slit portion 132 is a slit-like space extending inside the inner ring portion 103 and extending in the circumferential direction of the rotating shaft 50, in other words, along the inner circumferential surface of the inner ring portion 3 and the outer circumferential surface of the bearing pad 4. The space is filled with lubricating oil. Further, the inner ring slit portion 132 is disposed at substantially the same position as the bearing pad 4 in the circumferential direction of the rotating shaft 50.
The inner ring slit portion 132 communicates with the space between the rotation shaft 50 and the inner ring portion 103 or the space between the rotation shaft 50 and the outer ring portion 2 at the axial end of the rotation shaft 50.

FIG. 3 is a cross-sectional view for explaining another embodiment of the inner ring portion of FIG.
As shown in FIG. 3, the inner ring slit portion 132 may be provided with a communication portion 133 that extends radially inward at the end portion, and is not particularly limited.
The communication part 133 is a flow path extending radially inward from an end in the circumferential direction of the inner ring slit part 132, and a flow path that connects the space between the rotation shaft 50 and the inner ring part 103 and the inner ring slit part 132. It is.

Next, the support of the rotating shaft 50 in the bearing 101 having the above configuration will be described.
In addition, about the effect | action of the bearing pad 4, the pad slit part 41, the press screw part 21, etc., since it is the same as that of 1st Embodiment, the description is abbreviate | omitted.

Here, the operation of the inner ring slit portion 132 will be described.
Like the pad slit portion 41, the inner ring slit portion 132 is filled with lubricating oil, and thus has a damping effect.
Specifically, when a portion of the inner ring portion 103 between the bearing pad 4 and the inner ring slit portion 132 is displaced, a damping effect for the displacement of the portion is brought about.

  According to said structure, the inner ring | wheel slit part 132 is formed in the inner ring | wheel part 103, and the inner ring | wheel part 103 can also be given a damping effect by filling lubricating oil etc. in the inside.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
The basic configuration of the bearing of this embodiment is the same as that of the first embodiment, but the peripheral configuration of the pressing screw portion is different from that of the first embodiment. Therefore, in the present embodiment, only the peripheral configuration of the pressing screw portion will be described with reference to FIG. 4, and description of other components will be omitted.
FIG. 4 is a cross-sectional view illustrating the configuration of the bearing according to the present embodiment.
In addition, about the component same as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 4, the pressing portion 221 in the bearing 201 is disposed on the outer ring portion 2, and the radially inner end thereof is in contact with the outer peripheral surface of the inner ring portion 3.
Specifically, the pressing part 221 can change the radial position of the pressing part 221 with respect to the outer ring part 2. As a structure of the press part 221, a well-known structure can be used and it does not specifically limit.

As shown in FIG. 4, a control unit 222 that controls an arrangement position with respect to the outer ring unit 2 is connected to the pressing unit 221 in the bearing 201.
The control unit 222 controls the arrangement position of the pressing unit 221 in the radial direction according to the number of rotations of the rotation shaft 50 and a load related to the rotation shaft 50.

  According to said structure, according to the rotation state of the rotating shaft 50, for example, the rotation speed, the clearance gap between the rotating shaft 50 and the bearing pad 4 can be maintained at an appropriate value.

1,101,201 Bearing 2 Outer ring part (bearing housing)
3,103 Inner ring part (support part)
4 Bearing pad 21 Pressing screw part (pressing part)
31 Connection part 41 Pad slit part 50 Rotating shaft 132 Inner ring slit part (housing slit part)
221 Pressing unit 222 Control unit

Claims (4)

A bearing that rotatably supports a rotating shaft,
A support portion for accommodating the rotating shaft therein;
A plurality of bearing pads disposed between the rotating shaft and the support;
A connecting portion that connects the supporting portion and the bearing pad, and supports the bearing pad so as to be displaceable about an axis extending in parallel with the rotation shaft;
Between the support portion and the bearing pad, a pad slit portion extending from the connection portion along one direction and the other direction in the circumferential direction of the rotating shaft is provided,
The bearing between the support part and the bearing pad, which is the width dimension of the pad slit part, is 0.0005 times or more and 0.002 times or less with respect to the radius of the rotating shaft.   The bearing according to claim 1, wherein a housing slit portion that extends along the circumferential direction and extends along the rotation shaft is provided inside the support portion. A bearing housing that houses the support portion therein;
A pressing portion that is disposed between the support portion and the bearing housing and presses the support portion toward the rotation shaft;
The bearing according to claim 1, wherein the bearing is provided. The bearing according to claim 3, further comprising a control unit that adjusts a magnitude of a pressing force by the pressing unit according to a rotation state of the rotating shaft.

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