CN110702409B

CN110702409B - Elastic joint bearing fatigue test device

Info

Publication number: CN110702409B
Application number: CN201910939192.5A
Authority: CN
Inventors: 陈高升; 赖亮庆; 冯林兆; 尹建伟; 苏正涛; 刘嘉
Original assignee: AECC Beijing Institute of Aeronautical Materials
Current assignee: AECC Beijing Institute of Aeronautical Materials
Priority date: 2019-09-29
Filing date: 2019-09-29
Publication date: 2021-10-15
Anticipated expiration: 2039-09-29
Also published as: CN110702409A

Abstract

The invention belongs to a fatigue test technology, and relates to an elastic joint bearing fatigue test device, which is used for a dynamic torsion fatigue test of an elastic joint bearing under the loading conditions of radial pre-tightening force and axial pre-tightening force. Two elastic knuckle bearings are symmetrically installed on a torsion shaft (4), constant axial pretightening force is applied through distance control of bolts at two ends of the torsion shaft (4), constant radial pretightening force is applied through a force sensor (8) connected with the torsion shaft (4), the torsion shaft (4) is connected with a connecting rod (5), the connecting rod (5) is connected with a lower pull rod (3) through a ball joint (9) with a handle, a transition connecting rod (10) is connected with the lower pull rod, and dynamic torsion load is applied to the knuckle bearings through displacement control of the lower pull rod (3). The invention has the advantages of simple structure, convenient manufacture, installation and maintenance, low cost and the like.

Description

Elastic joint bearing fatigue test device

Technical Field

The invention belongs to a fatigue test technology, and relates to a fatigue test device for an elastic joint bearing.

Background

The invention relates to an elastic joint bearing fatigue test device which is mainly used for a triaxial fatigue test of parts with symmetrical installation characteristics, wherein two axial directions are static loading, and one axial direction is dynamic loading.

The elastic joint bearing is a key elastic element of a helicopter tail rotor system, is symmetrically arranged on a tail rotor fork-shaped piece, realizes flapping motion of a tail blade through elastic deformation of a metal/rubber lamination, and simultaneously transmits lateral force generated by rotation motion of the tail blade to a tail rotor shaft. The elastic joint bearing simultaneously bears axial compression load, radial load and torsional load when in work, the service life of a part is a key technical assessment index, the part simultaneously considers multi-axial load to carry out fatigue test, and high requirements are provided for testing equipment and technology.

Disclosure of Invention

The purpose of the invention is: the fatigue test device for the elastic joint bearing is simple in structure, low in cost, convenient to install and maintain and long in service life.

In order to solve the technical problem, the technical scheme of the invention is as follows:

a joint bearing fatigue test device includes: the device comprises a fixed support 1, an upper pull rod 2, a lower pull rod 3, a torsion shaft 4, a connecting rod 5, a bearing 6, a radial bearing support 7, a force sensor 8, a ball joint with a handle 9, a transition connecting rod 10, a joint bearing 11, an axial locking nut 12 and a radial compression bolt 13;

the fixed support 1 is of a frame structure, and the upper pull rod 2 is fixedly connected with the fixed support 1;

the upper end of the force sensor 8 is in contact with the radial compression bolt 13, and the lower end of the force sensor is fixedly connected to the center of the support beam 71;

the radial bearing support 7 is positioned in the fixed support 1, has an inverted U-shaped cross section and is fixedly connected with a first vertical plate 72 and a second vertical plate 73 which are symmetrical left and right through a support cross beam 71;

bearings 6 are embedded in the symmetrical positions of the first vertical plate 72 and the second vertical plate 73 respectively, and torsion shafts 4 are supported by inner rings of the bearings 6; the torsion shaft 4 is connected with the connecting rod 5;

the handle parts of the two ball joints with handles 9 are connected, the lower pull rod 3 is connected with the ball joint with handles 9 at the lower part, and the ball joint with handles 9 at the upper part is connected with the connecting rod 5;

the upper pull rod 2 and the lower pull rod 3 are coaxial;

the knuckle bearings 11 are symmetrically arranged at two ends of the torsion shaft 4, the outer end heads of the knuckle bearings 11 are connected with the fixing support 1, and under torsion load, the outer end heads of the knuckle bearings 11 and the fixing support 1 are relatively fixed.

The joint bearing 11 consists of an inner end 1101, an outer end 1102, a metal spacer 1103 and a rubber layer 1104; the inner end 1101 and the metal spacers 1103, the outer end 1102 and the metal spacers 1103, and the adjacent metal spacers 1103 are vulcanization bonded together by the rubber layer 1104. Axial, radial and torsional loads are carried by the alternating metal spacers together with the rubber layers.

The force sensor 8 is specifically connected in the following manner:

one end of the radial compression bolt 13 is contacted with one end of a force sensor 8 through a threaded hole in the upper part of the fixed support 1; the center position above the bracket beam 71 is provided with a through hole, and the through hole is connected with the lower end of the force sensor 8 through a bolt.

The knuckle bearing 11 is fixed at both ends of the torsion shaft 4 by axial lock nuts 12.

Preferably, for the purpose of reducing weight, the external contour of the embedded bearing 6 of the first vertical plate 72 and the second vertical plate 73 is circular, and the part connected with the bracket beam 71 is rectangular.

Preferably, the connecting rod 5 is fork-shaped and is connected with the torsion shaft 4 through a bolt.

Preferably, the ball joints 9 with handles are connected through a transition connecting rod 10.

Preferably, the force sensor 8 is an S-shaped force sensor.

In another implementation, the bracket beam 71 and the first and

second risers

72, 73 can be integrally formed.

The invention has the beneficial effects that: the invention provides a simple fatigue testing device for an elastic joint bearing,

the dynamic torsional motion of the knuckle bearing is realized by the linear displacement control of the lower pull rod 3.

Axial pre-tightening force is applied through bolts at two ends of the torsion shaft 4; controlling the application of radial load through a force sensor; and dynamic torsional load is applied through displacement control of the lower pull rod 3, so that dynamic torsional fatigue loading of the joint bearing under the conditions of constant axial force and radial force load is realized.

The highest frequency of the dynamic torsion loading of the test device is not less than 40Hz, and the maximum torsion angle is not less than 5 degrees. The applicable temperature range of the test device is-45 ℃ to 100 ℃.

Compared with the traditional test equipment, the test equipment has the characteristics of simple structure, low test cost, convenience in maintenance, high test frequency, wide applicable temperature range and the like, greatly reduces the technical requirements and complexity of parts on the test equipment under a specific multi-axis loading condition, shortens the test period and can generate greater economic benefits.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings used in the embodiment of the present invention will be briefly explained. It is obvious that the drawings described below are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be obtained from these drawings without inventive effort.

FIG. 1 is a front view of a fatigue testing apparatus of the present invention;

FIG. 2 is a left side view of the fatigue testing apparatus of the present invention;

FIG. 3 is a right side view of the fatigue testing apparatus of the present invention;

FIG. 4 is a schematic cross-sectional view A-A of FIG. 1;

FIG. 5 is a schematic cross-sectional view B-B of FIG. 3;

FIG. 6 is a schematic cross-sectional view C-C of FIG. 3;

FIG. 7 is a schematic view of a radial load bearing support of the present invention;

FIG. 8 is a top view of the elastomeric spherical plain bearing of the present invention;

FIG. 9 is a schematic cross-sectional view D-D of FIG. 8;

FIG. 10 is an isometric schematic view of a resilient knuckle bearing;

FIG. 11 is a schematic illustration of the structural compression loads of an embodiment of the present invention;

FIG. 12 is a schematic illustration of radial and torsional loading for a structure according to an exemplary embodiment of the present invention;

the device comprises a fixing support 1, an upper pull rod 2, a lower pull rod 3, a torsion shaft 4, a connecting rod 5, a bearing 6, a radial bearing support 7, a force sensor 8, a ball joint with a handle 9, a transition connecting rod 10, a joint bearing 11, an axial locking nut 12, a radial compression bolt 13, a radial bearing support 7, a support cross beam 71, a first vertical plate 72 and a second vertical plate 73.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Features of various aspects of embodiments of the invention will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present invention by illustrating examples thereof. The present invention is not limited to any particular arrangement or method provided below, but rather covers all product structures, any modifications, alterations, etc. of the method covered without departing from the spirit of the invention.

In the drawings and the following description, well-known structures and techniques are not shown to avoid unnecessarily obscuring the present invention. As shown in fig. 1, 2 and 3, the external view of the fatigue testing device of the present invention is shown, and fig. 4, 5 and 6 are schematic views of the internal structure of the fatigue testing device of the present invention, including: the device comprises a fixed support 1, an upper pull rod 2, a lower pull rod 3, a torsion shaft 4, a connecting rod 5, a bearing 6, a radial bearing support 7, a force sensor 8, a ball joint with a handle 9, a transition connecting rod 10, a joint bearing 11, an axial locking nut 12 and a radial compression bolt 13; the structure of the radial bearing support 7 is shown in fig. 7, a support cross beam 71, a first vertical plate 72 and a second vertical plate 73 which are symmetrical left and right are connected into a whole body through bolts, and the fixed support 1 is formed by a mouth-shaped rigid frame and an inverted U-shaped beam into a whole body; the radial bearing support 7 can also be integrally formed by machining.

The fatigue test device of the elastic joint bearing needs to be fixed and loaded by a dynamic fatigue tester, a fixed support 1 keeps relatively static relative to the ground and a dynamic test rack in the operation process, one end of an upper pull rod 2 is fixedly connected with the fixed support 1, the other end of the upper pull rod is connected with a fixed end chuck of the dynamic tester, 2 joint bearings 11 are symmetrically arranged on a torsion shaft 4, the relative motion between the inner end head of each joint bearing and the torsion shaft in the torsion direction in the dynamic loading process is ensured through a positioning design, the outer end head of each joint bearing 11 is connected with the fixed support 1, the outer end head of each joint bearing keeps relatively static relative to the fixed support in the dynamic loading process, the outer end of the inner end head is pressed by bolts at the two ends of the torsion shaft to apply axial pretightening force to the joint bearing shaft, and the pretightening force can be controlled by the compression amount, in order to reduce friction and improve the fatigue life of the torsion shaft, rolling bearings 6 are arranged on two sides in the middle of the torsion shaft, the inner ring of each rolling bearing is connected with the torsion shaft, the outer ring of each rolling bearing is embedded into a radial bearing support 7, two ends of a force sensor 8 are respectively connected with a fixed support 1 and the radial bearing support 7, the force sensor and the fixed support are connected through bolts, the bolts are tightly pressed on the upper surface of the force sensor, the numerical value of force is controlled through compression, one end of a connecting rod 5 is fixedly connected with the torsion shaft 4, the other end of the connecting rod is connected with a ball joint 9 with a handle, the effective length L of the connecting rod 5 is comprehensively designed according to the dynamic torsion angle and the test frequency, under the same dynamic torsion angle and frequency, the longer the effective length L is, the longer the moving distance of an actuator of the testing machine in unit time is, the higher the performance requirement of the testing machine is, and the ball joints 9 with the handle are connected through transition connecting rods 10, the device is used for ensuring that the upper pull rod and the lower pull rod are always coaxial in the twisting motion process.

The implementation example is shown in attached

drawings

11 and 12, fig. 11 shows a fatigue form of symmetrically installing a pair of tail rotor elastic joint bearings, a single elastic joint bearing axially applies compression displacement of 0.3mm, applies static radial force of 1000N, has a dynamic torsion angle movement range of-10 degrees to 10 degrees and a test frequency of 30Hz, and can perform normal temperature, high temperature and low temperature fatigue tests according to the requirements of experimental technology, wherein the test temperature range is-40 ℃ to 80 ℃.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the present invention, and these modifications or substitutions should be covered within the scope of the present invention.

Claims

1. The utility model provides an elastic joint bearing fatigue test device which characterized in that: the elastic joint bearing fatigue test device comprises: the device comprises a fixed support (1), an upper pull rod (2), a lower pull rod (3), a torsion shaft (4), a connecting rod (5), a bearing (6), a radial bearing support (7), a force sensor (8), a ball joint with a handle (9), a transition connecting rod (10), a joint bearing (11), an axial locking nut (12) and a radial compression bolt (13);

the fixed support (1) is of a frame structure, and the upper pull rod (2) is fixedly connected with the fixed support (1);

the radial bearing support (7) is positioned in the fixed support (1), the cross section of the radial bearing support is of an inverted U-shaped structure, and the radial bearing support is formed by fixedly connecting a support cross beam (71) with a first vertical plate (72) and a second vertical plate (73) which are symmetrical left and right;

bearings (6) are embedded in the symmetrical positions of the first vertical plate (72) and the second vertical plate (73) respectively, and torsion shafts (4) are supported by inner rings of the bearings (6); the torsion shaft (4) is connected with the connecting rod (5);

the upper end of the force sensor (8) is in contact with the radial compression bolt (13), and the lower end of the force sensor is fixedly connected to the center of the support cross beam (71);

the handle parts of the two ball joints (9) with handles are connected, the lower pull rod (3) is connected with the ball joint (9) with handles at the lower part, and the ball joint (9) with handles at the upper part is connected with the connecting rod (5); the ball joints (9) with handles are connected through a transition connecting rod (10);

the upper pull rod (2) and the lower pull rod (3) are coaxial;

the knuckle bearings (11) are symmetrically arranged at two ends of the torsion shaft (4), and the knuckle bearings (11) are fixed at two ends of the torsion shaft (4) through axial locking nuts (12); the outer end of the joint bearing (11) is connected with the fixed support (1), and under the torsional load, the outer end of the joint bearing (11) and the fixed support (1) are relatively fixed;

the joint bearing (11) consists of an inner end head (1101), an outer end head (1102), a metal spacer (1103) and a rubber layer (1104); the inner end head (1101) and the metal spacers (1103), the outer end head (1102) and the metal spacers (1103) and the adjacent metal spacers (1103) are vulcanized and bonded together through rubber layers (1104); the highest frequency of dynamic torsion loading of the test device is not less than 40Hz, the maximum torsion angle is not less than 5 degrees, and the applicable temperature range is-45-100 ℃.

2. The elastic joint bearing fatigue test device according to claim 1, characterized in that: the force sensor (8) is specifically connected in the following manner:

one end of the radial pressing bolt (13) is contacted with one end of a threaded hole force sensor (8) on the upper part of the fixed support (1); the center position above the bracket cross beam (71) is provided with a through hole which is connected with the lower end of the force sensor (8) through a bolt.

3. The elastic joint bearing fatigue test device according to claim 1, characterized in that: the outer contours of the bearings (6) embedded in the first vertical plate (72) and the second vertical plate (73) are circular, and the parts connected with the support cross beam (71) are rectangular.

4. The elastic joint bearing fatigue test device according to claim 1, characterized in that: the connecting rod (5) is fork ear-shaped and is connected with the torsion shaft (4) through a bolt.

5. The elastic joint bearing fatigue test apparatus according to any one of claims 1 to 4, characterized in that: the force sensor (8) is an S-shaped force sensor.

6. The elastic joint bearing fatigue test apparatus according to any one of claims 1 to 4, characterized in that: the bracket beam (71) is integrally formed with a first vertical plate (72) and a second vertical plate (73).