JPS62159810A - Bearing supporting structure - Google Patents

Abstract

PURPOSE:To prevent reduction of internal efficiency of a machine by supporting a bearing or a bearing case in a bearing housing by means of supporting arms and making the distance between a point of application of force and the fulcrum of a hyraulic reaction force on the opposite surfaces of both the supporting arms and the bearing housing longer than that of the bearing. CONSTITUTION:A plurality of supporting arms 31 are disposed between an inside supporting sleeve 27 and an outside supporting sleeve 28 and a bearing case 25 is supported by a bearing housing 26 through the supporting arms 31 and an arm pivot 32. The extended length of the arm of the supporting arm 31 is made longer at the supporting sleeves 27, 28 side than that at the bearing case 25 side in relation to the arm pivot 32. Helical springs 34a, 34b are disposed between the supporting arms 31 and the inside and outside supporting sleeves 27, 28. Therefore, a design for enhancing internal efficiency of a machine can be facilitated and the effect of a damper for enabling a rotary body to be rotated quietly and stably can be rendered excellent.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a structure for supporting a radial bearing in the form of a horizontal bearing or a rolling bearing, and particularly to a structure for supporting a radial bearing in the form of a sliding bearing or a rolling bearing, and in particular for a compressor, a supercharger, a steam turbine, a gas turbine, etc. It is suitable for application to bearings that support high-speed rotating bodies.

<Prior art> Bearings that support a rotating body are generally used to support the weight of the rotating body and at the same time to support the forced vibration force caused by unbalance of the rotating body, and to support self-excitation due to the fluid action of the bearing or seal part. It is required to suppress vibration due to vibration and to block external forced vibration force transmitted from the bearing housing. In order to damp these vibrations and rotate the rotating body quietly and stably, it is necessary to provide a rotating shaft system consisting of the rotating body, a bearing, a bearing housing, etc. with a sufficient damping effect. in this case,
It has been shown that providing a damping effect to a part that rotates with the rotating body does not have a weak vibration damping effect, but can actually cause vibrations to diverge. It can be said that it is optimal to have an effect.

An example of such a conventional bearing support structure is shown in FIG.

A plurality of arc-shaped bearing pads 2 are arranged around the rotating body l.
are arranged with a gap 3 in between, and a ring-shaped bearing case 5 is superimposed on each of these bearing knots 2 via a bigot 4. An oil passage 7 is provided on the inner peripheral surface of the bearing housing song 6 in which the bearing nozzle 2 and the bearing case 5 are housed.
An annular support sleeve 8 with a
It has been supported through. An oil supply pipe 10 connected to a pressure oil supply source (not shown) communicates with an oil passage 11 formed in the bearing housing song 6, and a gap 12 between the support sleeve 8 and the bearing case 5 and an oil passage formed in the bearing case 5. Pressure oil is supplied to the gaps 3 between the rotary body 1 and the bearing knob 2 through the respective gaps 13, and an oil film is formed in these gaps 3 and 12. Seal rings 14a, 14b and oil drain seals 15a, 15b are disposed on the opposing surfaces of the bearing case 5, bearing housing song 6, and rotating body 1, respectively, to achieve a 1% lubricating oil flow rate and seal. Drained oil is led out from an oil drain pipe 16 connected to the lower end of the bearing housing song 6.

Therefore, an oil film that functions as a bearing that does not rotate with the rotating body is formed in the gap 12 on the outside of the lubricating oil film that is formed in the gap 3 as a bearing, so that the radial vibration generated in the rotating body l and the bearing housing 6 to rotating body l
The external vibration transmitted to the space squeezes the oil film in this gap 12 (5
(queeze) effect is attenuated or cut off, and quiet and stable rotation of the rotating body 1 can be maintained.

In addition, the elastic pin 9 is elastically deformed by the radial load acting on the rotating body 1, and the bearing case 5 is approximately coaxial with the support sleeve 8 (does not have to be completely coaxial). The radial gap 12 between the outer circumferential surface of the support sleeve 8 and the inner circumferential surface of the support sleeve 8 is maintained to be substantially equal over the entire circumference. Note that there is also one in which the support sleeve 8 is omitted and an oil film is formed directly between the bearing case 5 and the bearing housing 6.

<Problems to be Solved by the Invention> In such a conventional bearing support structure, in order to enhance the squeezing effect described above, it is necessary to This is an application example for a flat bearing, but a rolling bearing may be used instead of the bearing pad 2, in which case the rollers will affect the radial stiffness of the bearing.
The flexibility Plj of the elastic pin 9 and the stiffness of the oil film in the gap 12 must be made softer than that of the elastic pin 9. However, if the oil film rigidity is softened, the amount of displacement in the radial direction of the rotating body 1 increases, and the gap at the seal part inside the rotating body must be made wider compared to the case where the radial gap 12 is not provided. The leakage loss of the working fluid increases, resulting in a decrease in internal efficiency.

The present invention has been made in view of the above-mentioned problems of the prior art, and it has been made to expand the range of design options and facilitate the design with regard to the core holding mechanism of the bearing case such as an elastic pin, and the gap between the bearing case and the support sleeve. An object of the present invention is to provide a bearing support structure that prevents a decrease in internal efficiency of a machine and enables quiet and stable rotation of a rotating body.

Means for Solving the Problems> The configuration of the present invention to achieve the above object is such that a bearing that rotatably supports a rotating body or an annular bearing case superimposed on the bearing can be slightly displaced in the radial direction. in a bearing support structure, which is arranged in a bearing housing song and forms an oil film between opposing surfaces of the bearing housing and the bearing or the bearing case to damp vibrations between the rotating body and the bearing housing, arranged in an arc shape. The bearing or the bearing case is supported on the bearing housing via one end of a plurality of support arms, and the opposing surface facing the bearing nozzle via an oil film is formed to be longer than the other distance of the support arm. It is characterized by what it did.

〉 The oil film formed between the opposing surfaces of the support arm and the bearing nozzle as described above reduces the radial vibration generated in the rotating body as well as the external vibration transmitted from the bearing nozzle to the rotating body. The motion is attenuated or blocked, and the rotating body maintains quiet and stable rotation. In this case, the point of application of the oil film reaction force generated between the opposing surfaces of the support arm and the bearing housing song is located at a position farther away from the fulcrum of the support arm than the point of application of the force transmitted from the bearing or the bearing case. ,
Due to the lever principle, the radial displacement of the bearing or bearing case is magnified at the opposing surface between the support arm and the bearing nozzle, and the gap at the opposing surface becomes larger, even if the spring stiffness for core retention is softened. The displacement of the rotating body in the radial direction is suppressed to J-minimum.

<Embodiment> FIG. 1 shows a cross section showing a bearing support structure according to an embodiment of the present invention.

A plurality of arc-shaped bearing pads 22 are arranged around the rotating body 21 with a gap 23 in between, and an annular bearing case 25 is superimposed on each bearing pad 22 via a bearing bot 24. has been done. The bearing housing 26 in which the bearing notad 22 and the bearing case 25 are housed includes an annular inner support sleeve 27 and an annular outer support sleeve 12, respectively.
8 are integrally fitted, and a plurality of support arms 31 are arranged in an arc shape between the inner support sleeve 27 and the outer support sleeve 28 with gaps 29 and 30 interposed therebetween. There is. The bearing case 25 is supported by the bearing housing 26 via a support arm 31 and an arm pivot 32 that supports the support arm 31. Also, the support three 127 and 28 sides are longer. Bearing case 2 due to radial displacement of the rotating body 21
According to this principle, the displacement of 5 is magnified between the opposing surfaces of the support arm 31 and the support sleeve 27, 28.

In this embodiment, the bearing case 25 and the support arm 31 are made separately, but it is also possible to make them integrally in advance, and the inner support sleeve 27 and the outer support sleeve 2
8 and the spacer 33 for positioning these inner and outer support sleeves 27 and 28, as well as the bearing nozzle 26, were made separately. stomach.

A plurality of helical springs 34a, 34b are interposed in the radial direction between the support arm 31, the inner support sleeve 27, and the outer support sleeve 28, and the support arm 31 is interlocked with the radial load acting on the rotating body 21 VC. ,
The inner support sleeve 27 and the outer support sleeve 28 are maintained in a state in which they are substantially aligned (they do not need to be completely aligned), that is, the intervals between the gaps 29 and 30 are maintained to be substantially equal over the entire circumference.

This helical spring 34a in this embodiment.

It is also possible to use a disc spring, a leaf spring, etc. for the substitute υ of 34b.

Note that the gaps 29 and 30 can be widened according to the lever principle described above to increase the amount of displacement of the support arm 31, so instead of the helical springs 34a and 34b, rubber or plastic, which is relatively soft and has a damping effect, can be used. It is also possible to use a non-metallic material having a core retention function as well as an additional damping function. In addition, the design selection range regarding the temperature characteristics of these nonmetallic materials is such that the position of the gap 29, 30 is far from the bearing joint 22 or the bearing case 25, which prevents heat transfer from the bearing bag or the rotating body 21. Since it does not receive the shadow directly, it can be spread over a wide area.

On the other hand, an oil supply pipe 35 connected to a pressure oil supply source (not shown) communicates with an oil passage 36 formed in the bearing housing song 26.
This oil passage 36 is divided into oil passages 37 and 38. Oil road 37
Pressure oil is supplied to the gap 23 between the rotating body 21 and the bearing nokko 22 through an oil passage 39 formed in the support arm 31 and an oil passage 40 formed in the bearing case 25.
From the oil passage 4 formed in the outer support sleeve 28 [and the gap 3o via the oil passage 42 formed in the support arm 31]
Pressure oil is supplied to the pipe 9, and these gaps 23, 29.

An oil film was formed at around 30 pm. Seal rings 43a, 43b and oil drain seals 44a, 4 are provided on the opposing surfaces of the bearing case 25, the bearing housing 26, and the rotating body 21, respectively.
4b, seal rings 43a, 43b, oil drain seals 44a, 44. The lubricating oil flow rate adjustment and sealing are performed by b. In addition, the bearing housing 26
O-rings 45a and 45b are disposed around the oil passages 37 and 39 that communicate with the support arm 31.
, 45b seal the lubricating oil so as not to restrict the displacement of the support arm 31 in the radial direction. The drain oil is led out from an oil drain pipe 46 connected to the lower end of the bearing housing 26.

Therefore, an oil film that functions as a damper that does not rotate with the rotating body is formed on the outside of the lubricating oil film that is formed in the gap 23 as a bearing, so that the radial vibration generated in the rotating body 21 and the bearing Housing 26
External vibrations transmitted to the rotating body 21 are attenuated or blocked by the squeezing effect of the oil film in the gaps 29 and 30, and quiet and stable rotation of the rotating body 21 can be maintained.

<Effects of the Invention> The bearing support structure of the present invention supports the bearing or the bearing case in a lever-like manner by the support arm, so that even if the displacement and gap of the support arm are increased at the oil film formation position having a damper function, the bearing Or the displacement of the bearing case is l.
・In addition to expanding the range of design options to improve the internal efficiency of the machine and simplifying the design,
It is possible to obtain an excellent damper effect that enables quiet and stable rotation of the rotating body.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a bearing support structure according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional bearing support structure. In the drawing, 21 is a rotating body, 22 is a bearing pad, 23, 29, 30 is a gap, 25 is a bearing case, 26 is a bearing housing, 27 is an inner support sleeve, 28 is an outer support sleeve, and 31 is a support arm. 32 is the arm pivot. 34a, 34b are helical springs, 36.37, 38, 39, 40, 41.42 are oil passages, 3
5 is an oil supply pipe, and 46 is an oil drain pipe.

Claims (1)

[Claims] A bearing that rotatably supports a rotating body or an annular bearing case overlaid on the bearing is disposed in the bearing housing so as to be able to be slightly displaced in the radial direction, and between the facing surfaces of the bearing housing and the bearing or the bearing case. In a bearing support structure that forms an oil film to damp vibrations between the rotating body and the bearing housing, the bearing or the bearing case is supported by the bearing housing via one end of a plurality of support arms arranged in an arc shape. An opposing surface that faces the bearing housing via an oil film is arranged annularly at the other end of the support arm, and the distance from the point of application of the hydraulic reaction force of the opposing surface to the fulcrum of the support arm is determined by the distance between the bearing or the bearing. The bearing support structure is formed to be longer than the distance from the point of application of the hydraulic reaction force of the case to the fulcrum of the support arm.