CN110081077B - A kind of high radial stability elastic bearing - Google Patents

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

A kind of high radial stability elastic bearing

technical field

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

Background technique

Helicopter is an important force in national economic construction, especially in earthquake relief and emergency rescue, which plays an irreplaceable role. The rotor is the key moving part of the helicopter, providing the lift and control force required for the helicopter to fly. The rotor technology directly affects the performance of the helicopter, which represents the advanced level of the helicopter and is also an important symbol of the helicopter's generation. In the fully articulated rotor configuration, there are a large number of various metal bearings in the propeller hub due to the existence of the swing hinge, the swing hinge and the variable pitch hinge, resulting in a complex structure of the propeller hub, a large number of parts, and high manufacturing costs. , the maintenance cost is expensive, the maintenance workload is large, and the safety is relatively poor. In order to simplify the propeller hub, in the early 1960s, the world began to develop elastic bearings for rotor systems to replace swing hinges, swing hinges and variable pitch hinges. In the spherical flexible rotor configuration, the three hinge functions of swing hinge, swing hinge and variable pitch hinge are realized by elastic bearing. At present, metal bearings are replaced in full articulated, universal articulated, new hingeless, and new hingeless. Ball-flex rotors with elastic bearings can reduce weight by 35% and reduce the number of parts by 60%, significantly improving helicopter performance. Elastic bearings have been widely used in many helicopters at home and abroad.

The laminated spherical rubber-metal elastic bearing is a composite structure in which multiple spherical rubber layers with the same spherical center and spherical metal spacers are alternately bonded to each other. As an important component of the helicopter rotor system, it is between the hub and the central piece. It acts as a flexible connection and is usually used under certain pressure and torsional and bending loads to reduce the torsional, flapping and swaying loads on the central part during the rotation of the blade. Dynamic characteristics have an important impact.

As the tonnage of the helicopter increases, the rotor swing load will increase, and the radial and axial loads on the elastic bearing will also increase. The existing spherical elastic bearing will lead to the eccentric instability of the metal-rubber stack when the radial load increases, which will cause uneven stress on the rubber layer inside the spherical elastic bearing, resulting in a rapid decline in the performance of the rubber layer and early fatigue failure. Therefore, it can be said that the existing spherical elastic bearing has poor ability to resist radial load, and its service life will be greatly reduced due to the increase of radial load.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a spherical elastic bearing structure with high radial stability, large bearing capacity and long service life.

The technical scheme of the present invention is: a high radial stability elastic bearing, the high radial stability elastic bearing comprises a small joint 1, several layers of first spherical center spherical rigid spacers 2, several layers of first spherical center spherical surface rubber layers 3. The intermediate rigid transition piece 4, several layers of the second spherical center spherical rigid spacer 5, several second spherical center spherical surface rubber layers 6 and large joints 7, wherein the upper and lower parts of each layer of the first spherical center spherical surface rigid spacer 2 are The first spherical surface rubber layer 3 of the spherical center is bonded to the surface of the sphere, and is superimposed to form the first spherical center integral structure. The first spherical center spherical surface rubber layer 3 of the lowermost layer is bonded and connected with the intermediate rigid transition piece 4; the upper and lower spherical surfaces of each second spherical center spherical surface rigid spacer 5 are bonded with a second spherical center spherical surface rubber layer 6. , and superimposed to form a second spherical center overall structure, the second spherical center spherical surface rubber layer 6 on the uppermost layer of the second spherical center spherical surface rubber layer 6 is bonded and connected with the intermediate rigid transition piece 4, and the second spherical center spherical surface rubber layer 6 on the bottommost layer is connected with The large joint 7 is glued and connected.

Preferably, several layers of the first sphere-centered spherical rigid spacer 2 are installed concentrically in the overall structure of the first sphere center; several layers of the second sphere-centered spherical rigid spacer 5 are concentric in the second sphere center overall structure. Install with heart.

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

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

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

Preferably, the number of layers of the first spherical-centered spherical rigid separator 2 is 6-25 layers.

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

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

Preferably, the number of layers of the second spherical-centered spherical rigid separator 4 is 3-20 layers.

Preferably, the thickness of the second spherical center spherical rigid spacer 4 is 0.5 mm˜1.2 mm.

The advantages of the present invention are: the advantage of the present invention is that the design of two groups of concentric spherical rigid spacers with different ball center positions improves the stability of the spherical elastic bearing against radial load, reduces the spherical elastic bearing near the small joint side The strain energy density of the rubber layer greatly increases the overall life of the spherical elastic bearing.

Description of drawings

FIG. 1 is a cross-sectional view of the existing elastic bearing comparison scheme.

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

FIG. 3 is a plan view of FIG. 2 .

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

Detailed ways

The present invention will be described in further detail below.

Referring to FIGS. 2 to 4 , FIG. 2 is a schematic structural diagram of an embodiment of a high radial stability elastic bearing of the present invention, FIG. 3 is a top view of FIG. 2 , and FIG. 4 is a cross-sectional view of FIG. 3 . In this embodiment, the highly radially stable elastic bearing includes small joints 1 , several layers of first spherical-centered spherical rigid spacers 2 , several layers of first spherical-centered spherical surface rubber layers 3 , intermediate rigid transition pieces 4 , and several layers of first spherical surface rigid spacers 2 . Two spherical-centered spherical rigid spacers 5, several layers of second spherical-centered spherical rubber layers 6 and large joints 7, wherein the first spherical-centered spherical rigid spacers 2 are bonded together through the first spherical-centered spherical surface rubber layer 3. One end of the first spherical rigid spacer 2 is connected with the small joint 1 and the other end is connected with the intermediate rigid transition piece 4; the second spherical rigid spacer 5 is connected by the second spherical rubber The layer 6 is bonded as a whole, and one end of the second sphere-centered spherical rigid spacer 5 is connected with the intermediate rigid transition piece 4 , and the other end is connected with the large joint 7 .

First, design different structural schemes, calculate the anisotropic stiffness of different structural schemes and the strain distribution curve of each spherical rubber layer under different stress states through finite element, and check whether the stiffness values of different design schemes meet the design index requirements. In the structural scheme of technical indicators, the strain distribution curve of the adhesive layer is comprehensively compared, and the basic structural form of the high radial stability elastic bearing is finally determined.

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

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

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

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

The working principle of the invention is as follows: the elastic bearing is installed between the central piece of the rotor hub of the helicopter and the swinging support arm of the blade. When the rotor is working, the elastic bearing bears the huge centrifugal force load generated by the rotation of the rotor blade, and the elastic bearing also needs to meet the requirements of the blade swinging up and down, front and rear swing, and left and right variable pitch three-degree-of-freedom motion, that is, the elastic bearing bears the "pressure". -torsion-shear-bending" complex alternating loads. When the radius of curvature of the spacer in the elastic bearing decreases, the radial stiffness of the elastic bearing will increase. Under the same radial vibration load conditions, as the radial stiffness of the elastic bearing increases, the deformation of the metal-rubber stack will decrease, the strain received by the rubber layer will decrease, and the outer edge of the rubber layer will be deformed. The strain energy density will also decrease. The use of the double-ball core spacer stack design improves the radial stiffness of the elastic bearing on the one hand, that is, the ability to resist radial loads and the radial stability of the elastic bearing, on the other hand, reduces the rubber layer. Strain energy density at the outer edge. For the same rubber material, the smaller the strain energy density it receives, the better the fatigue performance, that is, the longer the time to fatigue failure, and the longer the fatigue life for elastic bearings.

Example 1

A high radial stability elastic bearing, as shown in Figure 2 to Figure 4. The small joint 1, the intermediate transition rigid part 4 and the large joint 7 are made of aluminum alloy. The first spherical surface rubber layer 3 and the second spherical center spherical surface rubber layer 5 are made of NR1055 natural rubber compound.

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 sphere centers of the two spherical surfaces are 10mm apart.

The first sphere-centered spherical rigid spacer 2 has a total of 12 layers in one set, and the thickness of the first sphere-centered spherical rigid spacer 2 is all 0.8 mm.

The second sphere-centered spherical rigid spacer 5 has a total of 5 layers in one set, and the thickness of the second sphere-centered spherical rigid spacer 5 is also 0.8 mm.

In order to facilitate the comparison of the improvement of this technology in improving the radial resistance of the elastic bearing, a general elastic bearing comparison scheme is provided for comparison with this embodiment. The general elastic bearing includes a small joint, a set of concentric spherical rigid spacers, and several layers of spherical surfaces. Rubber layers and large joints. The spherical rubber layer is made of NR1055 natural rubber compound, a set of spherical rigid spacers with concentric spheres has a total of 18 layers, and the spherical rubber layer has a total of 19 layers. Table 1 shows the comparison results of various stiffnesses and fatigue life between the comparative scheme and the present embodiment. It can be seen from Table 1 that each stiffness is improved, and the fatigue life is also greatly improved.

Table 1 Comparison results of stiffness and fatigue life between the comparative scheme and this embodiment

Claims (10)

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.

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