JPH07119743A - Squeeze film damper - Google Patents

Abstract

PURPOSE:To provide the squeeze film damper which is simple in structure, and has no fear of oil leakage. CONSTITUTION:A clearance 1 which will be a squeeze acting surface, is formed between a damper movable section 2 and a damper support section 3, and oil is supplied to the clearance 1 from an oil basin 5. Each groove in a ring shape 6 is provided for side sections at the outer circumferential sides of the damper support section 3, and also for side sections at the inner circumferential sides of the damper movable section 2. Each elastic film 4 is interposed between the damper support section 3 and the damper movable section at both the sides of them, the both the end sections of each elastic film 4 are inserted in the insides of the grooves 6, and fixed and sealed therein thereafter. As mentioned above, the clearance 1 between the damper support section 3 and the damper movable section, which will be a squeeze acting surface, is sealed by each elastic film 4 so that no oil leaks outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a squeeze film damper applied to a bearing or the like of a rotary machine for the purpose of damping vibration.

[0002]

A squeeze film damper is a squeeze effect of oil, that is, a non-compressible material having a viscosity between two surfaces when moving at a relative speed in a direction to increase or decrease a gap between the two surfaces. It is a vibration attenuator that utilizes the effect that oil produces a damping force according to the speed. This damping is intensified when the gap between the surfaces is narrowed, so that there is a feature that a large damping can be obtained even with a relatively small size. Squeeze film dampers are installed outside the bearings of gas turbines and compressors, and serve as a vibration control function. The conventional squeeze film damper requires lubrication system because it is lubricated and lubricated at the same time as the bearing, and the lubrication oil cannot completely seal the application range because the lubrication oil pollutes the environment. .

Therefore, a squeeze film damper having a closed structure in which oil is shielded from the outside by a diaphragm has been proposed. FIG. 5 shows an example of a conventional squeeze film damper having such a sealed structure. This will be described below. In FIG. 5, 24 is an inner ring of a ball bearing, 23 is a ball of a ball bearing, and 22 is an outer ring thereof. This bearing outer ring 2
An annular inner damper movable member 16 is fixed to the outer periphery of the inner damper movable member 16, and an elastic diaphragm 15 is sandwiched between the inner damper movable member 16 and the outer damper movable member 14 divided into two screws.
It is fixed at 9. The outer damper movable member 14 is surrounded by a damper support member 13 with the gaps 12 and 12 being surrounded by the damper support member 13. A part of the gap 12 forms an oil sump 21.
A thrust receiver 18 is screwed into one end of the damper support member 13 with a seal ring 20 interposed.

Pressing members 17, 17 are screwed into the other end of the damper support member 13 and the end of the thrust receiver 18 so as to sandwich both side edges of the diaphragm 15, and the diaphragm 15 has a gap 12. 12 and the oil sump 21 are shielded from the outside. Hydraulic oil is filled in the gaps 12, 12 and the oil sump 21. The oil stored in the oil sump 21 is supplied to the gaps 12, 12 between the damper support member 13 and the outer damper movable member 14. Inner ring of ball bearing 2
The vibration force generated by the rotating body (not shown) supported inside 4 is the inner ring 24, the ball 23, the outer ring 22, and the inner damper movable part 1
6, outer damper movable portion 14, gap 12, damper support portion 13
However, the vibration is damped by the squeeze effect of the oil in the gaps 12 and 12 during the transmission.

The ball bearing portion shown in the figure is lubricated only with a solid lubricant, and no oil is used. As described above, in the conventional squeeze film damper having a closed structure, the oil sump 21 and the gaps 12 and 12 are completely shielded from the outside by the diaphragm 15, so that the working oil does not leak to the outside. Also, since the ball bearing does not use lubricating oil, it does not pollute the environment. However, such a conventional device has a drawback that the structure is complicated and it is difficult to manufacture.

[0006]

As described above, in the squeeze film damper, unless the lubricating oil is surely prevented from flowing out, the lubricating oil will leak out and cause trouble. It is an object of the present invention to provide a squeeze film damper that has a simple structure and that does not pollute the environment due to oil leakage. Another object of the present invention is to provide a squeeze film damper capable of exerting a sufficient vibration damping function while eliminating the risk of oil leakage with a simple structure.

[0007]

According to the present invention, oil is interposed in a gap between a vibrating surface and a surface supporting the vibrating surface, and the oil generates a damping force according to the increasing / decreasing speed of the gap. In order to solve the above-mentioned problems in the squeeze film damper used, an elastic film covers a gap between the two surfaces, and ends of the elastic film are respectively formed into grooves provided in a member forming the two surfaces. Adopt a structure that is fixed by inserting.

To insert and fix the end of the elastic film into the groove of the member, an adhesive can be used, or a low melting point metal such as solder, silver braze or brass braze can be used. . That is, the adhesive is filled between the groove and the end of the elastic film inserted therein to utilize the fixing force of the adhesive, or the temperature is improved by filling the wax between the groove and the end of the elastic film. The end of the elastic film is firmly fixed to the groove by utilizing the fixing force when the liquefied wax which is raised and solidifies.

[0009]

Since the squeeze film damper is used to damp vibrations, it is sufficient that the gap between the squeeze surfaces is about 10 times the generated vibration. That is, since the movable range is very narrow, about 10 times the vibration, in the squeeze film damper of the present invention, the oil is sealed by using the elastic film that freely deforms without disturbing the vibration. That is, in the squeeze film damper according to the present invention, a groove formed by covering a gap portion between two surfaces consisting of a vibrating surface and a surface supporting the vibrating surface with end portions respectively provided on the members forming the two surfaces. Since the elastic film is fixed inside, the oil in the gap is reliably sealed so as not to leak to the outside.

Moreover, the relative displacement between the two surfaces is not disturbed at all because the film is an elastic film, and the desired function as a squeeze film damper can be exhibited. Further, the elastic film is easy to manufacture because its ends are fixed in the grooves provided in the members forming the two surfaces by adhesion or brazing.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A squeeze film damper according to an embodiment of the present invention will be specifically described below with reference to FIGS. In FIG. 1, reference numeral 1 is a gap formed between the damper support portion 3 and the damper movable portion 2, and the oil stored in the oil reservoir 5 is supplied to the gap 1. An annular groove 6 is formed on the inner peripheral side of the damper movable part 2 and the outer peripheral side of the damper support part 3 as shown in the figure. On the other hand, an elastic film 4 is arranged on the side portions of the damper movable portion 2 and the damper support portion 3 so as to cover the gap 1. A bellows-like fold is formed on the elastic film 4 as shown in the figure. Both ends of the elastic film 4 are inserted into the grooves 6 provided in the damper movable portion 2 and the damper support portion 3.

FIG. 2 shows a state in which the end portion of the elastic film 4 thus inserted in the groove 6 is fixed with the adhesive 7.
The liquid adhesive 7 is filled between the groove 6 and the elastic film 4 inserted therein. Then, after adhering one end to the groove, the elastic film 4 is inverted and filled with lubricating oil, and then the other end is similarly adhered into the groove 6.

FIG. 3 shows a state in which the end portion of the elastic film 4 is fixed to the groove 6 by using a metal alloy brazing material. That is, the groove 6
The end of the elastic film 4 is inserted into the end of the elastic film 4 at the same time as the end of the elastic film 4 as shown in FIG. Keep airtight between the groove and the groove 6. The exothermic agent includes gunpowder and alumina. To prevent deterioration of the lubricating oil, cool it immediately after the wax melts after filling the lubricating oil. The wax may be melted by induction heating instead of the exothermic agent.

In this way, both ends of the elastic film 4 are fixed in the damper movable portion 2 and the groove 6 of the damper support portion 3 to form a complete seal portion. Since the elastic film 4 is formed with pleats as shown in the figure, the damper movable portion 2 and the damper support portion 3 can be freely displaced relative to each other with the gap 1 as a boundary. Like the squeeze film damper shown in FIG. 5, the damper movable portion 2 shown in FIG. 1 is used to support the bearings of a rotating machine and the like to suppress the vibration.

The present invention has been specifically described above based on the illustrated embodiments, but the present invention is not limited to these embodiments, and the shape and structure thereof are within the scope of the present invention shown in the claims. It goes without saying that various changes may be added to the. For example, although the squeeze film damper applied to the bearing of the rotary machine has been described in the above embodiments, the squeeze film damper according to the present invention is not limited to the bearing, and may be applied to a mounting portion of a structure or the like.

[0016]

As described above in detail, according to the present invention, oil is interposed in the gap between the vibrating surface and the surface that supports the vibrating surface, and the oil has a damping force according to the increasing / decreasing speed of the gap. In a squeeze film damper that utilizes the generation of a squeeze film, the squeeze film damper has an elastic film in which a gap portion between the two surfaces is covered, and end portions of the squeeze film damper are fixed in a groove provided on a member side forming the two surfaces. The two surfaces are covered with an elastic film so that the oil existing between them does not leak outside. Moreover, since the elastic film covers the two surfaces, the relative displacement between the two surfaces is free, and the intended function of the squeeze film damper is not hindered. Further, in the squeeze film damper according to the present invention, the elastic film is simply fixed in the groove provided on the side of the member forming the two surfaces, so that the structure is simple and the manufacturing is easy.

[Brief description of drawings]

FIG. 1 is a sectional view of a sealed squeeze film damper bearing according to an embodiment of the present invention.

FIG. 2 is a sectional view of a mounting portion in the embodiment shown in FIG.

FIG. 3 is a sectional view similar to FIG. 2, but showing another configuration of the mounting portion.

FIG. 4 is a cross-sectional view showing a brazing filler and a heating agent used in the mounting portion shown in FIG.

FIG. 5 is a sectional view showing a conventional squeeze film damper.

[Explanation of symbols]

 1 Clearance of squeeze surface 2 Damper movable part 3 Damper support part 4 Elastic film (cover) 5 Oil sump 6 Groove 7 Adhesive 8 Wax 9 Exothermic agent

Front page continuation (72) Inventor Isahiko Masada 5-717-1, Fukahori-cho, Nagasaki-shi Nagasaki Research Institute, Mitsubishi Heavy Industries, Ltd.

Claims (1)

[Claims] 1. A squeeze film damper, wherein oil is interposed in a gap between a vibrating surface and a surface supporting the vibrating surface, and the oil generates a damping force according to an increasing / decreasing speed of the gap. A squeeze film damper having an elastic film which covers a gap between two surfaces and is fixed by inserting an end portion into a groove provided in a member forming each of the two surfaces.