CN110081077B

CN110081077B - High radial stable elastic bearing

Info

Publication number: CN110081077B
Application number: CN201910283844.4A
Authority: CN
Inventors: 赖亮庆; 陈高升; 苏正涛; 刘嘉
Original assignee: AECC Beijing Institute of Aeronautical Materials
Current assignee: AECC Beijing Institute of Aeronautical Materials
Priority date: 2019-04-09
Filing date: 2019-04-09
Publication date: 2020-09-22
Anticipated expiration: 2039-04-09
Also published as: CN110081077A

Abstract

The invention belongs to the design technology of an elastic bearing structure, and relates to a high-radial-stability elastic bearing. The high radial stable elastic bearing basically comprises a small joint, a plurality of first spherical center spherical rigid spacers, a plurality of first spherical center spherical rubber layers, a middle rigid transition piece, a plurality of second spherical center spherical rigid spacers, a plurality of second spherical center spherical rubber layers and a large joint. The spherical elastic bearing has the advantages that the stability of the spherical elastic bearing for resisting radial load is improved and the strain energy density of the spherical elastic bearing close to the small joint side rubber layer is reduced through the design of two groups of concentric spherical rigid spacers with different spherical centers, so that the overall service life of the spherical elastic bearing is greatly prolonged.

Description

High radial stable elastic bearing

Technical Field

The invention belongs to the design technology of an elastic bearing structure, and relates to a structure of a high-radial-stability elastic bearing.

Background

The helicopter is an important force for national economic construction, and plays an irreplaceable role in earthquake relief and emergency rescue. The rotor wing is a key moving part of the helicopter and provides lift force and operating force required by the helicopter in flying. The rotor wing technology directly influences the performance of the helicopter, represents the advanced degree of the helicopter and is an important mark for the generation of the helicopter. In a fully articulated rotor configuration, due to the presence of flapping hinges, shimmy hinges and pitch hinges, a large number of various metal bearings are present in the hub, resulting in a hub with a complex structure, a large number of parts, high manufacturing cost, expensive maintenance, large maintenance workload and poor safety. To simplify the hub, elastic bearings for rotor systems were developed around the world in the early 60's of the 20 th century to replace flapping, shimmy and pitch hinges. In the configuration of the spherical flexible rotor wing, the functions of swinging hinge, shimmy hinge and pitch-variable hinge are integrated by the elastic bearing. At present, metal bearings are replaced in a full-hinged type, a universal hinged type, a novel hingeless type and a novel hingeless type. The ball flexible rotor wing adopting the elastic bearing can reduce weight by 35 percent and reduce the number of parts by 60 percent, thereby obviously improving the performance of the helicopter. Elastic bearings have been widely used on numerous helicopters at home and abroad.

The laminated spherical rubber-metal elastic bearing is a composite structure formed by alternately bonding a plurality of spherical rubber layers with the same spherical center and a spherical metal spacer, is used as an important component of a helicopter rotor system, plays a flexible connection role between a hub and a central part, is usually used under certain pressure, torsion and bending loads, reduces torsion, flapping and shimmy loads generated to the central part in the rotating process of a blade, and has important influence on the dynamic characteristics of the rotor system by the various rigidity performance indexes of the elastic bearing.

Along with the increase of the tonnage of the helicopter, the shimmy load of the rotor wing can be increased, and the radial load and the axial load of the elastic bearing can be increased. The existing spherical elastic bearing can cause eccentric instability of a metal-rubber lamination under the condition of increasing radial load, so that the stress of an inner rubber layer of the spherical elastic bearing is uneven, the performance of the rubber layer is rapidly reduced, and the early fatigue failure is caused. Therefore, it can be said that the existing spherical elastic bearing has poor capability of resisting radial load, and the service life of the spherical elastic bearing is greatly reduced due to the increase of the radial load.

Disclosure of Invention

The purpose of the invention is: overcomes the defects of the prior art, and provides a spherical elastic bearing structure with high radial stability, large bearing capacity and long service life.

The technical scheme of the invention is as follows: a high radial stable elastic bearing comprises a small joint 1, a plurality of first spherical center spherical surface rigid spacers 2, a plurality of first spherical center spherical surface rubber layers 3, a middle rigid transition piece 4, a plurality of second spherical center spherical surface rigid spacers 5, a plurality of second spherical center spherical surface rubber layers 6 and a large joint 7, wherein the upper spherical surface and the lower spherical surface of each first spherical center spherical surface rigid spacer 2 are respectively bonded with the first spherical center spherical surface rubber layer 3 and are overlapped to form a first spherical center integral structure, the first spherical center spherical surface rubber layer 3 at the uppermost layer of the first spherical center integral structure is bonded with the small joint 1, and the first spherical center spherical surface rubber layer 3 at the lowermost layer is bonded with the middle rigid transition piece 4; the upper and lower spherical surfaces of each layer of second spherical center spherical rigid spacer 5 are respectively bonded with a second spherical center spherical rubber layer 6 and are overlapped to form a second spherical center integral structure, the second spherical center spherical rubber layer 6 on the uppermost layer of the second spherical center integral structure is bonded with the middle rigid transition piece 4, and the second spherical center spherical rubber layer 6 on the lowermost layer is bonded with the large joint 7.

Preferably, a plurality of layers of first spherical center spherical surface rigid spacers 2 are concentrically arranged in the first spherical center integral structure; several layers of second spherical rigid spacers 5 are concentrically mounted in the second spherical integral structure.

Preferably, the distance between the center of sphere O1 of the first center of sphere unitary structure and the center of sphere 02 of the second center of sphere unitary structure is 5mm to 50 mm.

Preferably, the bonding surface of the intermediate rigid transition piece 4 and the first spherical center spherical rubber layer 3 is a concave spherical surface concentric with the first spherical center integral structure, the spherical radius of the concave spherical surface is Ra, the bonding surface of the intermediate rigid transition piece 4 and the second spherical center spherical rubber layer 6 is a convex spherical surface concentric with the second spherical center integral structure, the spherical radius of the convex spherical surface is Rb, and Ra is greater than or equal to Rb.

Preferably, the spherical radius and the spherical area of each layer of the first spherical-center-spherical-rigid spacer 2 become larger layer by layer in the direction from the small joint 1 to the intermediate rigid transition piece 4.

Preferably, the number of the first spherical-center spherical rigid spacer 2 is 6 to 25.

Preferably, the thickness of the first spherical-center spherical rigid spacer 2 is 0.5mm to 1.2 mm.

Preferably, the spherical radius and the spherical area 7 of each layer of the second spherical-center spherical-surface rigid spacers 5 become larger layer by layer in the direction from the intermediate rigid transition piece 4 to the large joint.

Preferably, the number of the second spherical-center spherical rigid spacer 4 layers is 3 to 20.

Preferably, the thickness of the second centroidal spherical rigid spacer 4 is 0.5mm to 1.2 mm.

The invention has the advantages that: the spherical elastic bearing has the advantages that the stability of the spherical elastic bearing for resisting radial load is improved and the strain energy density of the spherical elastic bearing close to the small joint side rubber layer is reduced through the design of two groups of concentric spherical rigid spacers with different spherical centers, so that the overall service life of the spherical elastic bearing is greatly prolonged.

Drawings

Figure 1 is a cross-sectional view of a prior art elastomeric bearing comparison scheme.

Figure 2 is an isometric view of an embodiment of an elastomeric bearing structure of the present invention.

Fig. 3 is a top view of fig. 2.

FIG. 4 is a cross-sectional view A-A of FIG. 3, wherein 1-small joint, 2-first spherical center spherical rigid spacer, 3-first spherical center spherical rubber layer, 4-intermediate rigid transition piece, 5-second spherical center spherical rigid spacer, 6-second spherical center spherical rubber layer, 7-large joint.

Detailed Description

The present invention is described in further detail below.

Referring to fig. 2 to 4, fig. 2 is a schematic structural view of an embodiment of the high radial stability elastic bearing of the present invention, fig. 3 is a plan view of fig. 2, and fig. 4 is a sectional view a-a of fig. 3. In this embodiment, the high radial stable elastic bearing comprises a small joint 1, a plurality of layers of first spherical center spherical surface rigid spacers 2, a plurality of layers of first spherical center spherical surface rubber layers 3, a middle rigid transition piece 4, a plurality of layers of second spherical center spherical surface rigid spacers 5, a plurality of layers of second spherical center spherical surface rubber layers 6 and a large joint 7, wherein the first spherical center spherical surface rigid spacers 2 are bonded into a whole through the first spherical center spherical surface rubber layers 3, one end of the first spherical center spherical surface rigid spacer 2 bonded into a whole is connected with the small joint 1, and the other end is connected with the middle rigid transition piece 4; the second spherical center spherical surface rigid spacers 5 are bonded into a whole through the second spherical center spherical surface rubber layer 6, one end of the second spherical center spherical surface rigid spacers 5 which are bonded into a whole is connected with the middle rigid transition piece 4, and the other end of the second spherical center spherical surface rigid spacers is connected with the large joint 7.

Firstly, different structural schemes are designed, each direction rigidity of the different structural schemes and strain distribution curves of the spherical rubber layers in different stress states are calculated through finite elements, whether the rigidity values of the different design schemes meet the requirements of design indexes or not is checked, the strain distribution curves of the rubber layers are comprehensively compared in the structural schemes meeting the technical indexes of rigidity, and finally the basic structural form of the high-radial-stability elastic bearing is determined.

The high radial stable elastic bearing is characterized in that: the surface of the intermediate rigid transition piece 4 adjacent to the first spherical-center spherical-surface rigid spacer 2 is a concave spherical surface concentric with the first spherical-center spherical-surface rigid spacer 2, the spherical radius of the concave spherical surface is Ra, the surface of the intermediate rigid transition piece 4 adjacent to the second spherical-center spherical-surface rigid spacer 5 is a convex spherical surface concentric with the second spherical-center spherical-surface rigid spacer 5, the spherical radius of the convex spherical surface is Rb, and Ra is greater than or equal to Rb.

The high radial stable elastic bearing is characterized in that: the distance between the spherical center O1 of the first spherical-center spherical-surface rigid spacer 2 and the spherical center O2 of the second spherical-center spherical-surface rigid spacer 5 is 5mm to 50 mm.

The high radial stable elastic bearing is characterized in that: each layer of the first spherical center and spherical surface rigid spacers 2 is concentric, the spherical radius and the spherical area of each layer of the first spherical center and spherical surface rigid spacers 2 are gradually increased from the small joint 1 to the middle rigid transition piece 4, the number of the layers of the first spherical center and spherical surface rigid spacers 2 is 6-25, and the thickness is 0.5-1.2 mm.

The high radial stable elastic bearing is characterized in that: each layer of second spherical center spherical surface rigid spacer 5 is concentric, the spherical radius and the spherical area of the second spherical center spherical surface rigid spacer 5 are gradually increased from the middle rigid transition piece 4 to the large joint 7, the number of layers of the second spherical center spherical surface rigid spacer 4 is 3-20, and the thickness is 0.5-1.2 mm.

The working principle of the invention is as follows: the elastomeric bearing is mounted between the helicopter rotor hub centerpiece and the blade flapping arms. When the rotor moves, the elastic bearing bears huge centrifugal force load generated by rotation of the rotor blades, and the elastic bearing also needs to meet the requirements of three-degree-of-freedom motion of up-and-down flapping, front-and-back shimmy and left-and-right variable pitch of the blades, namely the elastic bearing bears complex alternating load of 'pressure-torsion-shear-bending'. When the radius of curvature of the diaphragm in the elastomeric bearing is reduced, the radial stiffness of the elastomeric bearing will increase. Under the same radial shimmy load condition of the elastic bearing, along with the increase of the radial rigidity of the elastic bearing, the deformation of the metal-rubber lamination is reduced, the strain received by the rubber layer is reduced, and the strain energy density at the outer edge of the rubber layer is also reduced. By adopting the double-spherical-core spacer lamination design, on one hand, the radial rigidity of the elastic bearing is improved, namely, the capability of resisting radial load is improved, the radial stability of the elastic bearing is also improved, and on the other hand, the strain energy density of the outer edge of the rubber layer is reduced. For the same rubber material, the lower the strain energy density it is subjected to, the better the fatigue performance, i.e. the longer the time to fatigue failure, and for elastomeric bearings the longer the fatigue life.

Example one

A high radial stability elastic bearing is shown in figures 2 to 4. The small joint 1, the intermediate transition rigid piece 4 and the large joint 7 are made of aluminum alloy materials. The first spherical center spherical rubber layer 3 and the second spherical center spherical rubber layer 5 adopt NR1055 natural rubber sizing material.

The spherical radius of the concave surface of the intermediate transition rigid part 4 is 68.3mm, the spherical radius of the convex surface is 62.5mm, and the spherical centers of the two spherical surfaces are separated by 10 mm.

The first spherical center and spherical surface rigid spacer 2 comprises 12 layers in total, and the thickness of the first spherical center and spherical surface rigid spacer 2 is 0.8 mm.

The second spherical center spherical surface rigid spacer 5 comprises 5 layers in total, and the thickness of the second spherical center spherical surface rigid spacer 5 is 0.8 mm.

In order to facilitate comparison of improvement of the technology on the radial resistance of the elastic bearing, a comparison scheme of a common elastic bearing is provided to be compared with the embodiment, and the common elastic bearing comprises a small joint, a set of spherical rigid spacers which are concentric, a plurality of spherical rubber layers and a large joint. The spherical rubber layer is made of NR1055 natural rubber, and a set of spherical rigid spacers concentric with the sphere has 18 layers, and the spherical rubber layer has 19 layers. Table 1 shows the results of comparison between the stiffness and the fatigue life of the comparative example and the present example, and it can be seen from table 1 that the stiffness is improved and the fatigue life is also greatly improved.

Table 1 comparison of various stiffness and fatigue life of the comparative scheme and the present embodiment

Claims

1. The utility model provides a high radial stable elastic bearing which characterized in that: the high-radial-stability elastic bearing comprises a small joint (1), a plurality of first spherical center and spherical surface rigid spacers (2), a plurality of first spherical center and spherical surface rubber layers (3), a middle rigid transition piece (4), a plurality of second spherical center and spherical surface rigid spacers (5), a plurality of second spherical center and spherical surface rubber layers (6) and a large joint (7), wherein the upper spherical surface and the lower spherical surface of each first spherical center and spherical surface rigid spacer (2) are respectively bonded with the first spherical center and spherical surface rubber layers (3) and are overlapped to form a first spherical center integral structure, the first spherical center and spherical surface rubber layer (3) on the uppermost layer of the first spherical center integral structure is bonded with the small joint (1), and the first spherical center and spherical surface rubber layer (3) on the lowermost layer is bonded with the middle rigid transition piece (4); the upper spherical surface and the lower spherical surface of each layer of second spherical center spherical rigid spacer (5) are respectively bonded with a second spherical center spherical rubber layer (6) and are overlapped to form a second spherical center integral structure, the second spherical center spherical rubber layer (6) on the uppermost layer of the second spherical center integral structure is bonded with the middle rigid transition piece (4), and the second spherical center spherical rubber layer (6) on the lowermost layer is bonded with the large joint (7).

2. The high radially stable elastomeric bearing of claim 1, wherein: a plurality of layers of first spherical center spherical surface rigid spacers (2) are concentrically arranged in the first spherical center integral structure; and a plurality of layers of second spherical center spherical surface rigid spacers (5) are concentrically arranged in the second spherical center integral structure.

3. The high radially stable elastomeric bearing of claim 1, wherein: the distance between the sphere center O1 of the first sphere center integrated structure and the sphere center 02 of the second sphere center integrated structure is 5 mm-50 mm.

4. The high radially stable elastomeric bearing of claim 2, wherein: the bonding surface of the middle rigid transition piece (4) and the first spherical center spherical rubber layer (3) is a concave spherical surface which is concentric with the first spherical center integral structure, the spherical radius of the concave spherical surface is Ra, the bonding surface of the middle rigid transition piece (4) and the second spherical center spherical rubber layer (6) is a convex spherical surface which is concentric with the second spherical center integral structure, the spherical radius of the convex spherical surface is Rb, and Ra is larger than or equal to Rb.

5. The high radially stable elastomeric bearing of claim 1, wherein: in the direction from the small joint (1) to the intermediate rigid transition piece (4), the spherical radius and the spherical area of each layer of the first spherical center and spherical surface rigid spacer (2) become larger layer by layer.

6. The high radially stable elastomeric bearing of claim 1, wherein: the number of layers of the first spherical center and spherical surface rigid spacers (2) is 6-25.

7. The high radially stable elastomeric bearing of claim 6, wherein: the thickness of the first spherical center and spherical surface rigid spacer (2) is 0.5 mm-1.2 mm.

8. The high radially stable elastomeric bearing of claim 1, wherein: in the direction from the middle rigid transition piece (4) to the large joint, the spherical radius and the spherical area (7) of each layer of second spherical center spherical rigid spacers (5) become larger layer by layer.

9. The high radially stable elastomeric bearing of claim 1, wherein: the number of layers of the second spherical center spherical surface rigid spacer (4) is 3-20.

10. The high radially stable elastomeric bearing of claim 9, wherein: the thickness of the second spherical center spherical surface rigid spacer (4) is 0.5 mm-1.2 mm.