CN103383311A - Three crank-rocker mechanism joint bearing high-speed testing machine - Google Patents

Abstract

The invention discloses a high-speed testing machine for joint bearings of a three-crank rocker mechanism. The three cranks of the crankshaft are equipped with sliding bearing bushes I, II, and III, and the three high-frequency swing shafts I, II, and III are each supported on two rolling bearings. Above, the three high-frequency oscillating shafts Ⅰ, Ⅱ, and Ⅲ are connected in the same way as other components. Among them, one end of the high-frequency oscillating shaft Ⅰ is firmly connected to the inner ring of the test spherical plain bearing Ⅰ, and the outer ring of the test spherical plain bearing Ⅰ is connected to the The loading hydraulic cylinder I is fixedly connected, and the other end of the high-frequency swing shaft I is fixedly connected with the rocker I. The crankshaft with three crank throws of the present invention is designed as a dynamic balance structure with small impact and low noise. The invention carries out fatigue tests on three joint bearings at the same time, and can also carry out comparison fatigue tests on products of different batches and different manufacturers, and has high working efficiency. The oscillating frequency of the invention can reach 70-80 Hz, which can meet the requirements of high-frequency oscillating aviation joint bearing fatigue test.

Description

Three-crank rocker mechanism joint bearing high-speed testing machine

technical field

The invention relates to a high-speed testing machine for joint bearings of a three-crank rocker mechanism.

Background technique

Spherical joint bearing is a kind of sliding bearing with special structure, which is mainly composed of an inner ring with an outer spherical surface and an outer ring with an inner spherical surface. Joint bearings are widely used in the connection of swing components of aviation vehicles because of their flexible rotation, maintenance-free, compact structure, easy assembly and disassembly, large load-carrying capacity, and long life.

During the flight of an aircraft, the failure of any component will cause catastrophic consequences. Therefore, it is a very serious and important work to determine the service life of the components of the aircraft. In order to accurately determine the service life of the components of the aircraft, the usual practice is to carry out fatigue tests on the components of the aircraft under simulated real working conditions, and then divide the fatigue life obtained through the test by a safety factor, which is the component of the aircraft. Component service life.

As one of the important components of aerospace vehicles, spherical plain bearings must also undergo fatigue tests under simulated real working conditions. The oscillating frequency of joint bearings on some aviation vehicles is very high (30-70 Hz), while the joint bearing fatigue testing machines currently used in my country mostly use crank slider mechanisms, because it is difficult for this mechanism to achieve dynamic balance of moving components, so its highest oscillating frequency Generally, it does not exceed 20Hz, which cannot meet the requirements of the fatigue test of high-frequency oscillating aviation joint bearings, which seriously restricts the development of domestic high-frequency oscillating aviation joint bearings.

Contents of the invention

In order to overcome the above-mentioned shortcomings of the existing joint bearing fatigue testing machine using a crank slider mechanism, the present invention provides a high-speed testing machine for joint bearings with a three-crank rocker mechanism. In this invention, the crankshaft with three crank throws is a dynamic balance structure, and the movement mode of the three crank swing rod mechanisms is approximately symmetrical, and the inertial loads generated during the movement of the three connecting rods are partially canceled out, so the impact is small and the noise is low.

The technical solution adopted by the present invention to solve the technical problem is: a high-speed testing machine for joint bearings of a three-crank rocker mechanism, including connecting rods I, II, III, rockers I, II, III, pin shafts I, II, III , Sliding bearings Ⅰ, Ⅱ, Ⅲ, rolling bearings Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ, Ⅵ, Ⅶ, Ⅷ, couplings and motors. One end of the crankshaft with three crankshafts supported on the rolling bearing III is connected to the motor through a coupling, and three sliding bearing bushes I, II, III are installed on the three crankshafts of the crankshaft, and the sliding bearing bushes and the crankshaft It constitutes a rotating dynamic connection; three high-frequency swing shafts I, II, and III are supported on two rolling bearings. One end of three high-frequency swing shafts I, II, III and three test joint bearings I, II, III, three test joint bearings I, II, III, and three loading hydraulic cylinders I, II, III, and three high The other ends of the high-frequency oscillating shafts Ⅰ, Ⅱ, and Ⅲ are connected in the same way to the three rockers Ⅰ, Ⅱ, and Ⅲ. Among them, one end of the high-frequency oscillating shaft Ⅰ is firmly connected with the inner ring of the test joint bearing Ⅰ. The outer ring of the joint bearing Ⅰ is fixedly connected with the loading hydraulic cylinder Ⅰ, and the other end of the high-frequency oscillating shaft Ⅰ is connected with the rocker Ⅰ; the structure and size of the three rockers I, II, and III are also the same, and the three connecting rods The structure and size of Ⅱ and Ⅲ are also the same. Among them, there is a cylindrical hole at both ends of the connecting rod Ⅰ, one cylindrical hole is fixedly connected to the outer circle of the sliding bearing bush Ⅱ on the crankshaft, and the other cylindrical hole passes through the pin shaft Ⅰ and The cylindrical hole of the rocking rod I constitutes a rotational connection.

The three crank throws of the crankshaft are arranged alternately, the first crank throw is upward, that is, the eccentric distance between the crank throw axis and the crankshaft axis is upward; the second crank throw is downward, that is, the eccentric distance between the crank throw axis and the crankshaft axis is upward. Down; the third crankshaft is up, that is, the eccentric distance between the crankshaft axis and the crankshaft axis is upward.

The axes of the three high-frequency oscillating shafts I, II and III are all located in the same plane as the axis of the crankshaft and parallel to each other.

Compared with the prior art, the present invention has the following advantages: 1. The crankshaft with three crank throws of the present invention can be designed into a dynamic balance structure, that is, in the high-speed rotation process of the crankshaft, the centrifugal inertial force and centrifugal moment of inertia produced by the crankshaft itself When the crankshaft itself is balanced, the supporting bearings of the crankshaft will not be subjected to the centrifugal inertial force and centrifugal inertial moment. 2. The movement mode of the three crank swing rod mechanisms is approximately symmetrical, that is, when the left and right connecting rods swing upward perpendicular to the paper, the middle connecting rod swings downward perpendicular to the paper; when the left and right connecting rods move upward along the paper, the middle The connecting rods move downward along the plane of the paper, so that the inertial loads generated during the movement of the three connecting rods are partially offset by each other, so the impact is small and the noise is low. 3. The fatigue test can be carried out on three joint bearings at the same time, which improves the work efficiency. 4. Since the working conditions of the spherical plain bearings undergoing fatigue tests at the same time are exactly the same, it is possible to carry out comparative fatigue tests on spherical plain bearings of different production batches and different manufacturers. The oscillating frequency of the invention can reach 70-80 Hz, which can meet the requirements of high-frequency oscillating aviation joint bearing fatigue test.

Description of drawings

Fig. 1 is a top view sectional schematic diagram of the working state of the three-crank rocker mechanism joint bearing high-speed testing machine;

Fig. 2 is a schematic sectional view of A-A of Fig. 1;

Fig. 3 is the B-B sectional schematic diagram of Fig. 1;

Fig. 4 is the C-C sectional schematic diagram of Fig. 2;

Figure 5 is a three-dimensional schematic view of a crankshaft component with three crank throws.

In the above drawings, 1. Rocker I, 2, 4. Rolling bearings III, IV, 3. High-frequency swing shaft I, 5. Loading hydraulic cylinder I, 6. Test joint bearing I, 7, 13. Rolling bearings I, Ⅱ, 8. Sliding bearing Ⅰ, 9. Sliding bearing Ⅱ, 10. Connecting rod Ⅰ, 11 Connecting rod Ⅱ, 12. Crankshaft, 14. Coupling, 15. Motor, 16. Connecting rod Ⅲ, 17. Sliding bearing Ⅲ , 18, 22. Rolling bearing Ⅴ, Ⅵ, 19. Test joint bearing Ⅱ, 20. Loading hydraulic cylinder Ⅱ, 21. High-frequency swing shaft Ⅱ, 23. Rocker Ⅱ, 24. Rocker Ⅲ, 25, 29. Rolling bearing Ⅶ , Ⅷ, 26. High-frequency swing shaft Ⅲ, 27. Loading hydraulic cylinder Ⅲ, 28. Test joint bearing Ⅲ, 30. Pin shaft Ⅰ, 31. Pin shaft Ⅱ, 32. Pin shaft Ⅲ,

Detailed ways

Example

A schematic diagram of the working state of a three-crank rocker mechanism joint bearing high-speed testing machine shown in Figures 1 to 4. One end of the crankshaft 12 with three crankshafts supported on two rolling bearings I and II (7, 13) is connected to the motor (or hydraulic motor) 15 through a coupling 14, and the three crankshafts of the crankshaft 12 are arranged in a staggered manner. That is, the first bell crank is upward (the eccentric distance between the crank axis and the crankshaft axis is upward), the second crank is downward (the eccentric distance between the crank axis and the crankshaft axis is downward), and the third crank is upward (the eccentric distance between the crank axis and the crankshaft axis is downward). The eccentric distance between the crankshaft axis and the crankshaft axis faces upward). Install sliding bearing bush I8 on the first crankshaft on the left side of crankshaft 12 with three crankshafts, and install sliding bearing bush II9 on the second crankshaft on the left side of crankshaft 8 with three crankshafts. The third crankshaft on the left side of the crankshaft 8 with three crankshafts is installed with the sliding bearing bush III17, and the sliding bearing bushes I, II, III (8, 9, 17) form a rotational dynamic connection with the corresponding crankshafts (both They can rotate relative to each other, but cannot move axially). The high-frequency swing shaft I3 is supported on two rolling bearings III, IV (2, 4); the high-frequency swing shaft II21 is supported on two rolling bearings V, VI (18, 22); the high-frequency swing shaft 26III is supported on two rolling bearings VII, VIII (25, 29). The axes of the three high-frequency swing shafts I, II, III (3, 21, 26) are all located in the same plane as the axis of the crankshaft 12 with three crank throws, and are parallel to each other. One end of the high-frequency oscillating shaft I3 is firmly connected to the inner ring of the test spherical plain bearing I6, and the outer ring of the test spherical plain bearing 6 is firmly connected to the loading hydraulic cylinder I5; one end of the high-frequency swing shaft II21 is firmly connected to the inner ring of the test spherical plain bearing II19 , the outer ring of the test joint bearing II19 is firmly connected to the loading hydraulic cylinder II20; one end of the high-frequency swing shaft III26 is firmly connected to the inner ring of the test joint bearing III28, and the outer ring of the test joint bearing III28 is firmly connected to the loading hydraulic cylinder III27. There is a cylindrical hole at both ends of the rocker Ⅰ1, one of which is fixedly connected with one end of the high-frequency swing shaft I3; there is a cylindrical hole at both ends of the rocker II23, and one of the cylindrical holes is connected with the end of the high-frequency swing shaft Ⅱ21. One end is fixedly connected; the two ends of the rocker III24 respectively have a cylindrical hole, and one of the cylindrical holes is fixedly connected with one end of the high-frequency swing shaft III26. There is a cylindrical hole at both ends of the connecting rod Ⅱ11, one cylindrical hole is fixedly connected to the outer circle of the sliding bearing bush Ⅲ17, and the other cylindrical hole forms a rotational and dynamic connection with the cylindrical hole of the rocker Ⅱ23 through the pin shaft Ⅱ31 (the two can be relatively Rotate, but can not move relative to the axial direction); there is a cylindrical hole at both ends of the connecting rod I10, one cylindrical hole is fixedly connected to the outer circle of the sliding bearing bush II9, and the other cylindrical hole passes through the pin shaft I30 and the cylindrical hole of the rocker I1 It constitutes a rotational connection (the two can be rotated relative to each other, but cannot move relative to each other); there is a cylindrical hole at both ends of the connecting rod III16, one cylindrical hole is fixedly connected to the outer circle of the sliding bearing bush I8, and the other cylindrical hole passes through The pin shaft III32 and the cylindrical hole of the rocking rod II22 form a rotational and dynamic connection (the two can rotate relative to each other, but cannot move relative to the axial direction).

The working process of the present invention is as follows: the crankshaft, a crank throw on the crankshaft, a connecting rod, a rocker, a pin shaft, a high-frequency oscillating shaft, and rolling bearings and sliding bushes cooperating with them form a crank pendulum Rod mechanism, wherein the crankshaft and a crank throw on the crankshaft constitute the crank of the crank pendulum mechanism. Crankshaft 12, three connecting rods I, II, III (10, 11, 16), three rockers I, II, III (1, 23, 24), three pin shafts I, II, III (30, 31, 32 ), three high-frequency swing shafts Ⅰ, Ⅱ, Ⅲ (3, 21, 26) and the rolling bearings and sliding bushes that cooperate with them constitute three crank-swing bar mechanisms. When the electric motor (or hydraulic motor) 15 drives the crankshaft 12 to rotate at high speed through the coupling 14, the three high-frequency swing shafts I, II, III (3, 21, 26) rotate around their own axes at high frequency through the three crank swing rod mechanisms. Reciprocating and swinging, the inner rings of the three test joint bearings I, II, III (6, 19, 28) fixedly connected to the ends of the three high-frequency swing shafts I, II, III (3, 21, 26) will also follow the Due to the high-frequency reciprocating swing, the outer rings of the three test joint bearings Ⅰ, Ⅱ, Ⅲ (6, 19, 28) fixedly connected with the three loading hydraulic cylinders Ⅰ, Ⅱ, Ⅲ (5, 20, 27) are subjected to The limit of the loading hydraulic cylinder is fixed, so that the high-frequency reciprocating swing of the inner ring of the test joint bearing relative to the outer ring is realized, and the three loading hydraulic cylinders Ⅰ, Ⅱ, Ⅲ (5, 20, 27) give three Tension or pressure is applied to the outer rings of test spherical plain bearings Ⅰ, Ⅱ, Ⅲ (6, 19, 28), and the magnitude of the applied tension or pressure is controlled by the hydraulic system.

Claims (3)

1. crank and rocker mechanism oscillating bearing high-speed tester (HST), comprise connecting rod I, II, III, rocking bar I, II, III, bearing pin I, II, III, Sliding bush I, II, III, rolling bearing I, II, III, IV, V, VI, VII, VIII, shaft coupling and motor, it is characterized in that: the end with the bent axle of three crank throws that is bearing on rolling bearing I, II is connected with motor by shaft coupling, three Sliding bush I, II, III are installed on three crank throws of bent axle, and Sliding bush I, II, III and crank shaft formation are dynamically connected; Three swing in high frequency axle I, II, III respectively are bearing on two rolling bearings, one end of three swing in high frequency axle I, II, the III connected mode with the other end of three test oscillating bearing I, II, III, three loading hydraulic cylinder I, II, III and three swing in high frequency axle I, II, III and three rocking bar I, II, III respectively is all identical, wherein, one end of swing in high frequency axle I connects firmly with the inner ring of test oscillating bearing I, the outer ring of test oscillating bearing I all connects firmly with the loading hydraulic cylinder I, and the other end and the rocking bar I of swing in high frequency axle I connect firmly; The structure of three rocking bar I, II, III, measure-alike, three connecting rod I, II, the structure of III, size are also identical, wherein, respectively there is a cylindrical hole at the two ends of connecting rod I, a cylindrical hole connects firmly on the Sliding bush II cylindrical on bent axle, and another cylindrical hole is dynamically connected by the cylindrical hole formation of bearing pin I and rocking bar I.

2. three crank and rocker mechanism oscillating bearing high-speed tester (HST)s according to claim 1 is characterized in that: three crank throw alternative arrangement of described bent axle, first crank throw upwards, namely the eccentric throw of crank throw axis and crankshaft center line is up; Second crank throw is downward, and namely the eccentric throw of crank throw axis and crankshaft center line down; The 3rd crank throw makes progress, and namely the eccentric throw of crank throw axis and crankshaft center line up.

3. three crank and rocker mechanism oscillating bearing high-speed tester (HST)s according to claim 1, it is characterized in that: the axis of described three swing in high frequency axle I, II, III all is positioned at same plane with crankshaft center line, and parallel to each other.

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