A squeeze film damper with a semi-arc-shaped annular boost boss

Abstract

The present invention discloses a squeeze film damper with a semicircular annular boost boss, comprising a semicircular annular boss, and the semicircular annular boss is added to the axial ends of the damper outer ring and / or the damper inner ring respectively. In order to ensure that the working range of the damper does not exceed 0.4 times of the oil film gap, the radial height of the semicircular annular boss is the radius r, the radial height r of the semicircular annular boss does not exceed 0.5 times of the oil film gap, and is not less than 0.4 times of the oil film gap, the center of the semicircular annular boss is located at point O1 outside the axial plane of the damper inner ring or outer ring, with the axial section end point as the center O, and the radius R of the semicircular annular boss is the distance from O1 to the radial highest point of the semicircular annular boss, wherein the squeeze film damper of this structure can effectively play the role of oil film sealing, ensure the integrity of the oil film, increase the oil film pressure, inhibit the end air inhalation, improve the oil film damping, more efficiently absorb the energy generated by the rotor vibration, and improve the stability of the system.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation engine vibration reduction, and in particular relates to a squeeze film damper with a semi-bow annular supercharging boss. Background Art

[0002] Squeeze film dampers are commonly used in rotating machinery as a vibration reduction device. They reduce the vibration generated by the rotor by providing viscous damping. As rotating machinery develops towards high speed and high efficiency, higher requirements are also placed on the vibration reduction performance of squeeze film dampers.

[0003] For the damper, when the eccentricity (dynamic eccentricity / oil film gap) of the damper is not greater than 0.4, the oil film damping and stiffness are approximately considered to change linearly. When the eccentricity increases, nonlinear changes will occur.

[0004] The squeeze film damper can be divided into an open squeeze film damper without oil sealing and a closed squeeze film damper with oil sealing ring according to whether or not there is an end oil sealing device.

[0005] The lubricating oil in the open squeeze film damper fills the gap formed by the outer ring of the elastic support and the inner ring of the base. The external force generated by the vibration of the rotor squeezes the oil film, and the oil film generates an oil film reaction force to provide damping and absorb vibration energy. The shortcomings of the open damper are:

[0006] 1. Since there is no oil sealing device at both ends, the lubricating oil flows out directly along the two ends of the shaft, resulting in insufficient oil film extrusion at the ends, reducing the effective extrusion area of ​​the oil film and failing to generate sufficient oil film damping;

[0007] 2. The axial end is in direct contact with the outside air. When the oil film pressure is lower than the ambient pressure, air inhalation will occur. This phenomenon commonly occurs in open dampers, which will also cause the damping of the damper oil film to decrease and fail to produce a good vibration reduction effect.

[0008] The closed squeeze film damper has an oil sealing ring structure added to the end, which is generally an O-shaped oil sealing ring or a piston ring. The oil sealing ring can play a certain role in sealing the oil, with the purpose of maintaining the integrity of the oil film. However, the shortcomings of the closed damper are:

[0009] 1. The oil seal ring may have problems such as friction, assembly, manufacturing and replacement of the oil seal ring, which increases the uncertainty of the damping performance of the damper and affects the vibration reduction reliability of the damper.

[0010] 2. The oil seal ring can increase the damping effect of the damper, but there are problems such as the oil seal ring and the inner and outer rings of the damper rubbing for a long time, which leads to the oil being squeezed out at the end of the damper gap and the oil film temperature being too high. This will reduce the damping of the oil film and fail to produce a good vibration reduction effect.

[0011] Therefore, designing a damper with a semi-bowed annular boss can well compensate for the structural shortcomings of open and closed dampers. Adding a semi-bowed annular boss can improve the oil film damping and oil film pressure, enhance the end oil film extrusion effect, and suppress air intake. At the same time, the added semi-bowed annular boss also controls the working range of the damper to be no more than 0.4 times the oil film gap. Such a working range is to ensure that the oil film damping provided by the damper changes linearly and suppress the nonlinear change of the oil film stiffness. Summary of the invention

[0012] In view of the shortcomings of the existing squeeze film damper, the present invention proposes a squeeze film damper with a semi-arc annular boost boss, which can effectively play the role of oil film sealing, ensure the integrity of the oil film, increase the oil film pressure, inhibit the end air intake, improve the oil film damping, more efficiently absorb the energy generated by the rotor vibration, improve the stability of the system, and at the same time has a simple structure, strong reliability, and certain adaptability. The technical solution adopted by the present invention is as follows:

[0013] A squeeze film damper with a semi-arc annular boost boss comprises a damper base, a squirrel cage elastic support, an oil supply groove, and an oil supply hole. The inner ring of the damper base serves as the outer ring of the damper. The squirrel cage elastic support comprises a support section, a squirrel cage bar, and an extension section. The support section is fixedly connected to the damper base. The outer ring of the extension section serves as the inner ring of the damper. The outer ring of the damper forms a clearance fit with the inner ring of the damper, and the clearance is filled with lubricating oil to form an oil film. The outer ring of the damper is provided with an annular groove as the oil supply groove, and a through hole is provided to penetrate the oil supply groove as the oil supply hole. The bearing is concentrically assembled with the squirrel cage elastic support, and the rotor is sleeved in the bearing.

[0014] It also includes a semi-arc-shaped annular boss, and the semi-arc-shaped annular boss is added to the axial ends of the damper outer ring and / or the damper inner ring respectively.

[0015] In order to ensure that the working range of the damper does not exceed 0.4 times the oil film clearance, the radial height of the semi-arc annular boss is the radius r , the radial height of the semi-arcuate annular boss r Not more than 0.5 times the oil film gap, not less than 0.4 times the oil film gap, the center of the semi-arcuate annular boss is located at a point outside the axial plane of the inner ring or outer ring of the damper O 1 , with the end point of the axial section as the center O , the radius of the semi-arc annular boss R for O 1 The distance to the highest point of the semi-arcuate annular boss, where R = r .

[0016] The geometric shape of the semi-arc-shaped annular boss can increase the degree of radial extrusion of the boss on the oil film, and the top angle of the semi-arc-shaped annular boss is small, so that there is a large gap between the outer wall of the semi-arc-shaped annular boss and the inner wall of the damper, and no obvious friction will occur with the corresponding inner and outer walls of the damper when the damper is in working condition. Therefore, it also has a certain degree of adaptability to the working condition of the damper.

[0017] The beneficial effects of the present invention are as follows: a squeeze film damper with a semi-arc-shaped annular boost boss is provided by the present invention, and the semi-arc-shaped annular boss is formed by reasonable size setting, which has the following advantages:

[0018] (1) The present invention has a simple structure. A semi-arc-shaped annular boss is added at both axial ends of the damper inner ring and / or the damper outer ring, respectively, to form an integral oil sealing structure at both axial ends of the oil film, which hardly increases the difficulty of process manufacturing and processing cost.

[0019] (2) Compared with the traditional open damper, the end oil film pressure is increased, the axial outflow of lubricating oil is hindered, and the end air intake is suppressed, thus ensuring the integrity of the oil film.

[0020] (3) Compared with the traditional closed damper, the addition of a semi-bow fixed sealing structure at the end avoids excessive oil temperature and replacement of the oil seal ring, thus reducing the cost of use. At the same time, the extrusion force of the oil film at the end is changed, so that the oil film is subjected to annular extrusion, the pressure distribution at the end of the oil film changes, the pressure increases, and the damping of the oil film increases.

[0021] (4) By changing the extrusion direction of the oil film at the end, the oil film is squeezed more fully, the tangential force of the oil film is increased, the distribution range of the oil film damping is expanded, and the vibration reduction performance is improved.

[0022] (5) In order to assemble the semi-arc-shaped annular boss and the damper and prevent the semi-arc-shaped annular boss from rubbing against the damper, the radial height of the semi-arc-shaped annular boss is r It is set to no more than 0.5 times the oil film gap and no less than 0.4 times the oil film gap, and the damper working range is controlled to be no more than 0.4 times the oil film gap to ensure that the damper oil film damping changes linearly, while suppressing the nonlinear change of the damper oil film stiffness and improving the system stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a schematic structural diagram of a squeeze film damper of the present invention;

[0024] FIG2 is a schematic diagram of the structure of the semi-arcuate annular boss of the present invention, in which: (a) annular bosses are added to the inner and outer rings of the damper; (b) annular bosses are added to the inner ring of the damper; (c) annular bosses are added to the outer ring of the damper;

[0025] FIG3 is a partial enlarged view of the semi-arcuate annular boss of the present invention;

[0026] FIG4 is a schematic diagram of oil film extrusion of the present invention;

[0027] FIG. 5 is a schematic diagram of the geometric structure of the semi-arc-shaped annular boss of the present invention.

[0028] Explanation of symbols: 1-damper base; 2-damper outer ring; 3-squirrel cage elastic support; 32-support section; 34-squirrel cage bar; 36-extension section; 4-damper inner ring; 5-oil film; 6-oil supply groove; 7-oil supply hole; 8-rotor; 9-semi-arc annular boss. DETAILED DESCRIPTION

[0029] In order to enable a clearer understanding of the present invention, the present invention is further described in detail with reference to the accompanying drawings.

[0030] Refer to the following Figure 1-5 A squeeze film damper with a semi-arcuate annular boost boss provided according to an embodiment of the present invention is described.

[0031] like Figure 1 As shown, a squeeze film damper with a semi-arcuate annular boost boss comprises a damper base 1, the inner ring of the damper base 1 serves as a damper outer ring 2, a squirrel cage elastic support 3 comprises a support section 32, a squirrel cage bar 34, and an extension section 36, the support section 32 is fixedly connected to the damper base 1, the outer ring of the extension section 36 serves as a damper inner ring 4, the damper outer ring 2 and the damper inner ring 4 form a clearance fit, and the clearance is filled with lubricating oil to form an oil film 5; the damper outer ring 2 is provided with an annular groove as an oil supply groove 6, and a through hole is provided to penetrate the oil supply groove 6 as an oil supply hole 7, the bearing is concentrically assembled with the squirrel cage elastic support 3, and the rotor 8 is sleeved in the bearing.

[0032] like Figures 2 to 5 As shown, semi-arcuate annular bosses 9 are respectively added to the axial ends of the damper outer ring 2 and / or the damper inner ring 4 .

[0033] In order to ensure that the working range of the damper does not exceed 0.4 times the oil film clearance, the radial height of the semi-arcuate annular boss 9 is the radius r , the radial height of the semi-arcuate annular boss 9 r Not more than 0.5 times the oil film gap, not less than 0.4 times the oil film gap, the center of the semi-arcuate annular boss 9 is located at a point outside the axial plane of the inner ring or outer ring of the damper O 1 , with the end point of the axial section as the center O , the radius of the semi-arcuate annular boss 9 R for O 1 The distance to the radial highest point of the semi-arcuate annular boss 9, wherein R= r .

[0034] Working principle of the present invention: The squeeze film damper is based on the squeeze film principle. Specifically, when the rotor approaches the critical speed, the squeeze film damper of the present invention will generate a large external force and amplitude, which will be transmitted to the squeeze film damper through the bearing, and the radial oil film force distribution will be generated by the oil film between the outer ring of the squeeze damper and the inner ring of the damper. At the same time, the oil film will be squeezed by the semi-bow annular boss to generate an annular oil film force distribution, and the energy generated by the rotor vibration will be absorbed by the oil film force, so that the rotor can pass the critical speed as soon as possible, and the stability of the rotor system will be improved.

Claims

1. A squeeze film damper with a semi-arcuate annular boost boss, characterized in that: The invention comprises a damper base (1), a squirrel cage elastic support (3), an oil supply groove (6), and an oil supply hole (7); the inner ring of the damper base (1) serves as a damper outer ring (2); the squirrel cage elastic support (3) comprises a support section (32), a squirrel cage bar (34), and an extension section (36); the support section (32) is fixedly connected to the damper base (1); the outer ring of the extension section (36) serves as a damper inner ring (4); the damper outer ring (2) and the damper inner ring (4 ) form a clearance fit, the clearance is filled with lubricating oil to form an oil film (5); the damper outer ring (2) is provided with an annular groove as an oil supply groove (6), and a through hole is provided to penetrate the oil supply groove (6) as an oil supply hole (7); the bearing and the squirrel cage elastic support (3) are concentrically assembled, and the rotor (8) is sleeved in the bearing, characterized in that it also includes a semi-arc-shaped annular boss (9), and the semi-arc-shaped annular boss (9) is respectively added to the axial end of the damper outer ring (2) and / or the damper inner ring (4); The radial height of the semi-arc-shaped annular boss (9) r Not more than 0.5 times the oil film gap, not less than 0.4 times the oil film gap; The semi-arcuate annular boss (9) is located at a point outside the axial plane of the damper inner ring (4) or outer ring. O 1 , with the end point of the axial section as the center O , the radius of the semi-arcuate annular boss (9) R for O 1 The distance to the radial highest point of the semi-arcuate annular boss (9) R ,in R = r，r is the radial height of the semi-arcuate annular boss, O 1 O = r ; The center of the fan ring of the semi-arcuate annular boss (9) is O 1 , semi-arcuate shape O 1 The shape obtained by removing the isosceles right triangle with R as the hypotenuse and r as the right angle side from the sector with the center of the circle.

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