An engine thrust simulation device capable of achieving stable swing

Abstract

The present invention discloses an engine thrust simulation device capable of realizing stable swing, comprising: a gimbal seat, an adapter seat, bolts, nuts, an ear seat and an actuator; wherein the gimbal seat is fixed on a test platform; the adapter seat is connected to the gimbal seat through the bolts and the nuts, and the rotating shaft of the adapter seat is kept coaxial with the rotating shaft of the gimbal seat; the ear seat is connected to the actuator cylinder through threads, and the inner hole of the ear seat is docked with the rotating shaft of the adapter seat; one end of the actuator cylinder is fixed to the ground, and the other end of the actuator cylinder is threadedly connected to the ear seat. The present invention can measure the swing life and friction torque of the gimbal seat under vacuum thrust, and verify the rationality of the gimbal seat bearing matching clearance.

Description

Technical Field

[0001] The invention belongs to the technical field of rocket engines, and in particular relates to an engine thrust simulation device capable of realizing stable swinging. Background Art

[0002] As an important swing and force transmission link of the rocket engine, the swing life of the gimbal under thrust is an important criterion for its reuse. Currently, it can only be accumulated through a large number of ground swing thermal tests. However, due to the limitations of the engine swing time and number of swings, a single gimbal needs long-term matching and tracking statistics. At the same time, there is a risk of swing failure during the thermal test. It is even more difficult to obtain the swing life margin of the gimbal under vacuum thrust, which is not conducive to the early improvement design of the gimbal.

[0003] The friction torque of the gimbal under thrust load can be obtained by using the friction torque calculation formula of the sliding bearing or by linear fitting through the friction torque measurement value under low load to infer the friction torque under rated load. In addition, the friction torque of the gimbal under ground thrust can be measured through the ground swing heat test of the engine, and then the friction torque under vacuum thrust can be estimated.

[0004] When applying load to the gimbal using conventional methods and pushing the gimbal to swing, the load will shift and generate a deflection torque, resulting in unstable force driving the gimbal to rotate. At the same time, the friction torque of the loading link also increases significantly with the increase of load, seriously affecting the measurement accuracy. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to provide an engine thrust simulation device that can achieve stable swinging, to measure the swinging life and friction torque of the gimbal under vacuum thrust, and to verify the rationality of the gimbal bearing fit clearance.

[0006] The object of the present invention is achieved through the following technical solutions: an engine thrust simulation device capable of achieving stable swinging, comprising: a gimbal, an adapter, bolts, nuts, an ear seat and an actuator; wherein the gimbal is fixed on a test platform; the adapter is connected to the gimbal through the bolts and the nuts, and the rotating shaft of the adapter is coaxial with the rotating shaft of the gimbal; the ear seat is threadedly connected to the actuator, and the inner hole of the ear seat is docked with the rotating shaft of the adapter; one end of the actuator is fixed to the ground, and the other end of the actuator is threadedly connected to the ear seat.

[0007] In the above-mentioned engine thrust simulation device that can achieve stable swing, the adapter includes a force arm, a adapter body and a rotating shaft; wherein the force arm is connected to the adapter body, and the axis of the force arm coincides with the axis of symmetry of the adapter body; the rotating shaft is connected to the adapter body, and the axis of the rotating shaft is perpendicular to the axis of the adapter body.

[0008] In the above-mentioned engine thrust simulation device capable of realizing stable swinging, the force arm is provided with a loading hole A, and the loading hole A is connected to an external actuator cylinder through a spherical bearing.

[0009] In the above-mentioned engine thrust simulation device capable of realizing stable swing, the gimbal comprises a first ear seat assembly, a second ear seat assembly and a cross axis; wherein the first ear seat assembly comprises two first ear seats and a first base plate; wherein the two first ear seats are respectively connected to the two ends of the first base plate, and the two first ear seats are parallel; the second ear seat assembly comprises two second ear seats and a second base plate; wherein the two second ear seats are respectively connected to the two ends of the second base plate, and the two second ear seats are parallel; the cross axis comprises two second rotating shafts, two third rotating shafts, two first shaft hubs, two second shaft hubs and a connector; wherein the two second rotating shafts are connected to the connector through corresponding first shaft hubs; the two third rotating shafts are connected to the connector through corresponding second shaft hubs; the two second rotating shafts are symmetrically distributed about one axis of the connector; the two third rotating shafts are symmetrically distributed about another axis of the connector; the two first ear seats are respectively connected to the corresponding second rotating shafts, and the two second ear seats are respectively connected to the corresponding third rotating shafts; the first base plate and the second base plate are respectively located on both sides of the connector.

[0010] In the above-mentioned engine thrust simulation device that can achieve stable swing, the outer surfaces of the ear seat, the rotating shaft, the second rotating shaft and the third rotating shaft are all provided with a lubricating coating, wherein the lubricating coating includes epoxy resin, MoS2 powder, additives and diluent; wherein the mass ratio of epoxy resin, MoS2 powder, additives and diluent is 2.5:3:1:3.5.

[0011] In the above-mentioned engine thrust simulation device capable of realizing stable swing, the relationship between the rotational friction torque M3 of the joint bearing and the rotational friction torque M1 is obtained by the following formula according to the rotational friction torque M1 of the second shaft and the third shaft, the rotational friction torque M2 of the shaft, the rotational friction torque M3 of the joint bearing, and the action torque M4 of the external actuator: ; where the formula is:

[0012] ;

[0013] ;

[0014] Among them, the diameters of the second and third rotating shafts are both D1, the diameter of the rotating shaft is D2, the diameter of the joint bearing of the loading hole A is D3, the friction coefficients of the second and third rotating shafts are both μ1, the friction coefficients of the rotating shafts are both μ2, the friction coefficients of the joint bearings are both μ3, the load applied by the adapter to the gimbal is F, the force of the external actuator is F4, and the distance between the rotating shaft and the axis MM' of the loading hole A is H 22 .

[0015] In the above-mentioned engine thrust simulation device capable of achieving stable swaying, the additives are phthalic anhydride and antimony trioxide.

[0016] In the above-mentioned engine thrust simulation device capable of realizing stable swaying, the diluent is analytically pure cyclohexanol and analytically pure acetone.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention can measure the swing life and friction torque of the gimbal under vacuum thrust through the simulated loading device, and verify the rationality of the gimbal bearing fit clearance;

[0019] (2) The ear seat, the rotating shaft, the second rotating shaft and the third rotating shaft of the present invention are all provided with a lubricating coating, thereby extending the service life;

[0020] (3) The present invention increases the wear resistance and humidity environment adaptability of the lubricating coating through the composition of the lubricating coating;

[0021] (4) The present invention achieves high measurement accuracy of the rotational friction torque of the gimbal by using the relationship between the rotational friction torque M3 and the rotational friction torque M1 of the spherical bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0023] Figure 1 It is a structural schematic diagram of an engine thrust simulation device capable of achieving stable swaying provided by an embodiment of the present invention;

[0024] Figure 2 is a schematic diagram of the structure of the adapter provided by an embodiment of the present invention;

[0025] Figure 3 It is a schematic diagram of the structure of a gimbal provided in an embodiment of the present invention;

[0026] Figure 4 is a schematic structural diagram of a first ear seat assembly provided in an embodiment of the present invention;

[0027] Figure 5 is a schematic structural diagram of a second ear seat assembly provided by an embodiment of the present invention;

[0028] Figure 6 is a schematic structural diagram of a cross axis provided by an embodiment of the present invention;

[0029] Figure 7 is a top view of a cross axis provided by an embodiment of the present invention;

[0030] Figure 8 yes Figure 1 The enlarged view of point I in the middle;

[0031] Fig. 9 yes Figure 1 Enlarged view of point D in the middle. DETAILED DESCRIPTION

[0032] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] Figure 1 Schematic diagram of the structure of an engine thrust simulation device capable of achieving stable swing provided by an embodiment of the present invention. Figure 1 As shown, the engine thrust simulation device capable of realizing stable swinging comprises: a gimbal 1, an adapter 2, a bolt 3, a nut 4, an ear seat 5 and an actuator 6; wherein,

[0034] The gimbal 1 is fixed on the test platform; the adapter 2 is connected to the gimbal 1 by the bolt 3 and the nut 4, and the rotating shaft of the adapter 2 is kept coaxial with the rotating shaft of the gimbal 1; the ear seat 5 is connected to the actuator 6 by threads, and the inner hole of the ear seat 5 is docked with the rotating shaft of the adapter 2; one end of the actuator 6 is fixed to the ground, and the other end of the actuator 6 is threadedly connected to the ear seat 5.

[0035] like Figure 2As shown, the adapter 2 includes a force arm 21, a adapter body 22 and a rotating shaft 23; wherein the force arm 21 is connected to the adapter body 22, and the axis of the force arm 21 coincides with the axis of symmetry of the adapter body 22; the rotating shaft 23 is connected to the adapter body 22, and the axis of the rotating shaft 23 is perpendicular to the axis of the adapter body 22.

[0036] like Figure 2 As shown, the force arm 21 is provided with a loading hole A, and the loading hole A is connected to the external actuator through a joint bearing.

[0037] like Figure 3 As shown, the gimbal 1 includes a first ear seat assembly, a second ear seat assembly and a cross shaft 13; wherein,

[0038] like Figure 4 As shown, the first ear seat assembly includes two first ear seats 11 and a first bottom plate 12; wherein the two first ear seats 11 are respectively connected to two ends of the first bottom plate 12, and the two first ear seats 11 are parallel;

[0039] like Figure 5 As shown, the second ear seat assembly includes two second ear seats 14 and a second bottom plate 15; wherein the two second ear seats 14 are respectively connected to two ends of the second bottom plate 15, and the two second ear seats 14 are parallel;

[0040] like Figure 6 As shown, the cross shaft 13 includes two second rotating shafts 131, two third rotating shafts 134, two first shaft hubs 132, two second shaft hubs 135 and a connecting body 133; wherein the two second rotating shafts 131 are connected to the connecting body 133 through the corresponding first shaft hubs 132; the two third rotating shafts 134 are connected to the connecting body 133 through the corresponding second shaft hubs 135; the two second rotating shafts 131 are symmetrically distributed about one axis of the connecting body 133; the two third rotating shafts 134 are symmetrically distributed about the other axis of the connecting body 133;

[0041] like Figure 3 As shown, the two first ear seats 11 are respectively connected to the corresponding second rotating shafts 131 , and the two second ear seats 14 are respectively connected to the corresponding third rotating shafts 134 ; the first bottom plate 12 and the second bottom plate 15 are respectively located on both sides of the connecting body 133 .

[0042] The outer surfaces of the ear seat 5, the rotating shaft 23, the second rotating shaft 131 and the third rotating shaft 134 are all provided with a lubricating coating, wherein:

[0043] The lubricating coating includes epoxy resin, MoS2 powder, additives and diluent; wherein the mass ratio of epoxy resin, MoS2 powder, additives and diluent is 2.5:3:1:3.5.

[0044] MoS2 solid lubricating film uses epoxy resin as adhesive, MoS2 powder as lubricant, adds appropriate amount of additives (phthalic anhydride, antimony trioxide), and then mixes with diluent (analytical pure cyclohexanol, analytical pure acetone) to form a sprayable liquid. The mass ratio of each component is about 2.5:3:1:3.5. Sprayed on the surface of the part, it is cured at high temperature of 200℃ to form a solid lubricating film, and a lubricating coating with a micron thickness is formed on the friction part. The epoxy resin used in the solid lubricating film is 6101 epoxy resin that meets the HG2-741-72 standard, and the percentage content of the MoS2 powder particles with a diameter of ≤1.5μm is greater than 80%. By adding some other materials, the wear resistance of the coating and the adaptability to humidity environments can be increased.

[0045] Among them, the humidity is ≤60% and the temperature is 10℃~35℃, which can effectively ensure that the MoS2 solid lubrication film has a low friction coefficient and avoid being too different from the actual working environment to prevent excessive load torque from being required to overcome the rotational friction torque.

[0046] The diameters of the second rotating shaft 131 and the third rotating shaft 134 are both D1 (eg Figure 7 As shown in FIG. 2 ), the diameter of the rotating shaft 23 of the adapter is D2 (as shown in FIG. Figure 2 As shown in FIG. 1 ), the diameters of the first shaft hub 132 and the second shaft hub 135 are both D f (like Figure 7 As shown), the end surface clearance Δ between the gimbal hub and the connected ear seat 11 (like Figure 8 As shown), the radial clearance Δ between the gimbal shaft and the connected ear seat 12 (like Fig. 9 As shown), the gap Δ between the outer end face of the adapter and the end face of the connected ear seat 21 , radial clearance Δ between the adapter shaft and the connected ear seat 22 , the distance between the upper end surface of the adapter and its own rotation axis is H 21 , the distance H between the axis of the rotating shaft and the axis MM' of the loading hole A 22 ,

[0047] The gimbal shaft and the adapter shaft remain coaxial when installed. The sliding friction pairs of both use MoS2 solid lubrication film, and the friction coefficient should be no more than 0.1. In this way, the friction torque load can be approximately considered as twice that of the gimbal shaft, which is convenient for calculation and analysis of the test.

[0048] D f <H 21 , requiring Δ 11 ≈Δ 21 =0.5mm, the adapter should be strengthened along H 21 Otherwise, it is easy to cause the side of the adapter and the side of the ear seat to be squeezed and rubbed, causing structural damage and generating additional friction torque.

[0049] L 11 <L 21 , requiring Δ 12 ≈Δ 22 =0.5, the adapter should be strengthened along L 21 Otherwise, the shaft end of the adapter and the inner hole of the ear seat may get stuck, causing structural damage and destroying the lubricating coating.

[0050]

[0051]

[0052] From the above formula, we can get:

[0053] ;

[0054] In the formula: M1 is the rotational friction torque of a pair of rotating shafts of the gimbal; M2 is the rotational friction torque of a pair of rotating shafts of the adapter; M3 is the rotational friction torque of the rotating shaft of the loading hole A; M4 is the action torque of the external actuator; F is the load applied to the gimbal through the adapter; F4 is the action force of the external actuator; μ1 is the friction coefficient of the coating of the gimbal shaft; μ2 is the friction coefficient of the coating of the adapter shaft; μ3 is the friction coefficient of the coating of the loading hole shaft.

[0055] The loading hole A is a joint bearing, and a lubrication form with a friction coefficient equivalent to that of the MoS2 solid lubricant film should be selected. It can be seen from the above formula that the actuator applies a rotational torque through the loading hole. The deviation caused by the friction torque M3 of the joint bearing at this location is less than the rotational friction torque M1 of the gimbal, M3≤0.037M1, that is, no more than 3.7%, indicating that this test device has a high measurement accuracy for the rotational friction torque of the gimbal.

[0056] First, insert the two first ear seats 11 into the two second rotating shafts 131 at symmetrical positions, and then connect the first bottom plate 12 with the two first ear seats by screws; then insert the other two second ear seats 14 into the two third rotating shafts 134 perpendicular to the second rotating shafts 131, and then connect the second bottom plate 15 with the two second ear seats 14 by screws; the first bottom plate 12 and the second bottom plate 15 are respectively placed on both sides of the cross shaft 13. At this time, the product connected with the two bottom plates can swing around the rotating shaft 131 in an orthogonal direction.

[0057] The 1 / 2 thrust load is set symmetrically at two points on the swing axis of the gimbal, and the thrust load shaft is kept coaxial with the shaft of the gimbal. This ensures that during the swing of the gimbal, the shaft of the force always passes through the swing axis, and no additional torque is generated. The load action point remains unchanged, so the gimbal can swing stably at a certain frequency under the action of external force. At the same time, the material, fit size, fit clearance, and lubrication scheme of the load shaft and the gimbal mating pair are consistent, which can reduce the measurement deviation of the friction torque.

[0058] The material of the adapter seat 2 and the structural dimensions of the rotating shaft should be consistent with the journal of the gimbal seat 1, the inner diameter of the ear seat 5 should be consistent with the aperture of the gimbal seat 1, and the surface coating state of the inner hole and inner end face of the ear seat 5 and the shaft hole of the gimbal seat 1 should be consistent.

[0059] When installing the simulated loading device, first fix the gimbal 1 on the test platform, then dock the adapter 2 with the gimbal 1. At this time, the rotating shaft of the adapter remains coaxial with the rotating shaft of the gimbal, and then connect the ear seat 5 with the actuator 6 through threads, and dock the inner hole of the ear seat 5 with the rotating shaft of the adapter 2 in place. Finally, fix the actuator to the test platform 6 or the ground. When fixing, adjust and ensure that the rotating shaft of the actuator and the adapter is perpendicular, and maintain a certain gap between the inner end face of the ear seat 5 and the outer end face of the adapter 2 to prevent the ear seat 5 and the outer end face of the adapter 2 from getting stuck during the loading process.

[0060] When the simulated loading device is working, the actuator 6 applies a downward force to simulate the thrust of the engine, and then applies a tensile and compressive load with an initial direction perpendicular to the paper surface to the loading hole A of the adapter 2, driving the gimbal to swing along the inside and outside directions of the paper surface.

[0061] The axial distance between the loading hole A of the adapter and the rotating shaft of the gimbal is increased, generally more than 10 times the radius of the rotating shaft. While increasing the turning force arm, the required turning force can be significantly reduced. The loading hole A is connected to the external actuator through a spherical bearing, which will initially apply a turning force perpendicular to the paper surface. Properly reducing the turning force can reduce the friction torque of the spherical bearing. When it is necessary to measure the friction torque of the gimbal under the working load, first use the dynamic torque to subtract the friction torque of the spherical bearing. Considering that the load torque includes the rotating pair of the gimbal 1 and the rotating pair of the ear seat 5, when the rotating pair structures, fitting clearances and lubrication forms of the two places are consistent, the above torque difference can be divided by 2 to obtain the load torque of the gimbal.

[0062] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. An engine thrust simulation device capable of achieving stable swing, characterized in that include: A gimbal (1), an adapter (2), a bolt (3), a nut (4), an ear seat (5) and an actuator (6); wherein: The gimbal (1) is fixed on the test platform; The adapter seat (2) is connected to the gimbal seat (1) via the bolt (3) and the nut (4), and the rotating shaft of the adapter seat (2) is coaxial with the rotating shaft of the gimbal seat (1); The ear seat (5) is connected to the actuator cylinder (6) via threads, and the inner hole of the ear seat (5) is docked with the rotating shaft of the adapter seat (2); One end of the actuating cylinder (6) is fixed to the ground, and the other end of the actuating cylinder (6) is threadedly connected to the ear seat (5); The adapter seat (2) comprises a force arm (21), a adapter body (22) and a rotating shaft (23); wherein the force arm (21) is connected to the adapter body (22), and the axis of the force arm (21) coincides with the axis of symmetry of the adapter body (22); and the rotating shaft (23) is connected to the adapter body (22), and the axis of the rotating shaft (23) is perpendicular to the axis of the adapter body (22); The force arm (21) is provided with a loading hole A, and the loading hole A is connected to an external actuator cylinder via a joint bearing; The gimbal (1) comprises a first ear seat assembly, a second ear seat assembly and a cross shaft (13); wherein: The first ear seat assembly comprises two first ear seats (11) and a first bottom plate (12); wherein the two first ear seats (11) are respectively connected to two ends of the first bottom plate (12), and the two first ear seats (11) are parallel; The second ear seat assembly comprises two second ear seats (14) and a second bottom plate (15); wherein the two second ear seats (14) are respectively connected to two ends of the second bottom plate (15), and the two second ear seats (14) are parallel; The cross shaft (13) comprises two second rotating shafts (131), two third rotating shafts (134), two first shaft hubs (132), two second shaft hubs (135) and a connecting body (133); wherein: The two second rotating shafts (131) are connected to the connecting body (133) via corresponding first shaft hubs (132); The two third rotating shafts (134) are connected to the connecting body (133) via corresponding second shaft hubs (135); The two second rotating shafts (131) are symmetrically distributed about an axis of the connecting body (133); The two third rotating shafts (134) are symmetrically distributed about another axis of the connecting body (133); The two first ear seats (11) are respectively connected to the corresponding second rotating shafts (131), and the two second ear seats (14) are respectively connected to the corresponding third rotating shafts (134); the first bottom plate (12) and the second bottom plate (15) are respectively located on two sides of the connecting body (133); According to the rotational friction torque M1 of the second rotating shaft (131) and the third rotating shaft (134), the rotational friction torque M2 of the rotating shaft (23), the rotational friction torque M3 of the spherical bearing, and the action torque M4 of the external actuator, the relationship between the rotational friction torque M3 of the spherical bearing and the rotational friction torque M1 is obtained by the following formula: ; where the formula is: ； ； The diameters of the second rotating shaft (131) and the third rotating shaft (134) are both D1, the diameter of the rotating shaft (23) is D2, the diameter of the joint bearing of the loading hole A is D3, the friction coefficients of the second rotating shaft (131) and the third rotating shaft (134) are both μ1, the friction coefficients of the rotating shaft (23) are both μ2, the friction coefficients of the joint bearings are both μ3, the load applied by the adapter to the gimbal is F, the force of the external actuator is F4, and the distance between the rotating shaft (23) and the axis MM' of the loading hole A is H 22 ; The outer surfaces of the ear seat (5), the rotating shaft (23), the second rotating shaft (131) and the third rotating shaft (134) are all provided with a lubricating coating, wherein: The lubricating coating includes epoxy resin, MoS2 powder, additives and diluent; wherein the mass ratio of epoxy resin, MoS2 powder, additives and diluent is 2.5:3:1:3.

5.

2. The engine thrust simulation device capable of achieving stable swing according to claim 1, characterized in that: The additives are phthalic anhydride and antimony trioxide.

3. The engine thrust simulation device capable of achieving stable swing according to claim 1, characterized in that: The diluents are analytically pure cyclohexanol and analytically pure acetone.

Images