Variable-pitch rocker arm assembly fatigue test device and system

Abstract

The invention provides a variable-pitch rocker arm assembly fatigue test device which comprises a test piece installation assembly, a hydraulic loading assembly, a fixed frame assembly, an adjustable supporting assembly and a bottom fixing assembly, the test piece installation assembly and the fixed frame assembly are fixed to the bottom fixing assembly, one end of the hydraulic loading assembly is connected with the test piece installation assembly, and the other end of the hydraulic loading assembly is connected with the adjustable supporting assembly. The middle part of the fixed frame assembly is clamped on the adjustable supporting assembly; the fixed frame assembly plays a role in positioning and supporting the hydraulic loading assembly, and the hydraulic loading assembly provides loading force and a loading angle for the test piece mounting assembly, so that the test piece mounting assembly simulates the real loading state of a test piece on a machine; the loading structure and load characteristics can be simulated more truly, the result is more accurate and credible, and the total test error can be controlled within 3% when the device is used for testing.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fatigue test tooling design, and particularly relates to a variable-pitch rocker assembly fatigue test device and system. BACKGROUND

[0002] In a helicopter rotor system structure, as one of important parts of the helicopter rotor system, a variable-pitch rocker assembly is connected with a main hub arm assembly at one end and connected with a moving ring assembly through a variable-pitch link assembly at the other end, the rocker assembly transmits the control force to the variable-pitch mechanism to realize the control of the blades. The variable-pitch rocker is a key load-bearing moving part of the main hub of the helicopter, which needs to bear high-cycle fatigue load when the helicopter is flying, and the rigidity and durability thereof are directly related to the flight safety of the helicopter. In order to ensure the good performance and reliability of use, fatigue test should be carried out by simulating the load and structural characteristics to provide a basis for determining the service life.

[0003] The prior art and test conditions cannot truly simulate the load transmission relationship, and there is a large engineering simplification, and the total test error can reach about 10%. SUMMARY

[0004] The technical problem to be solved by the present application is that the prior art cannot truly simulate the load transmission relationship, there is a large engineering simplification, and the total test error can reach about 10%. The present application provides a variable-pitch rocker assembly fatigue test device, which can more truly simulate the installed structure and load characteristics, can more accurately determine the true fatigue performance and weak position of the variable-pitch rocker assembly, provide a basis for determining the service life, and the results are more accurate and reliable.

[0005] The technical scheme of the present application is:

[0006] A variable-pitch rocker assembly fatigue test device, comprising a test piece mounting assembly 10, a hydraulic loading assembly 20, a fixed frame assembly 30, an adjustable support assembly 40, and a bottom fixing assembly 50, the test piece mounting assembly 10, the fixed frame assembly 30, and the adjustable support assembly 40 are fixed on the bottom fixing assembly 50, one end of the hydraulic loading assembly 20 is connected with the test piece mounting assembly 10, the other end is connected with the fixed frame assembly 30, and the middle part is clamped on the adjustable support assembly 40; the fixed frame assembly 30 plays a positioning and supporting role for the hydraulic loading assembly 20, the hydraulic loading assembly 20 provides loading force and loading angle for the test piece mounting assembly 10, so that the test piece mounting assembly 10 simulates the real installed state of the test piece on the machine.

[0007] Optionally, the test piece mounting assembly 10 comprises a test piece 11, a test piece mounting support 12, a force loading fastening assembly 13, a test piece mounting fastening assembly 14, and an installation support fastening assembly 15,

[0008] The test piece mounting support 12 is connected and fastened with the bottom fixing assembly 50 through the mounting support fastening assembly 15, the test piece 11 is connected and fastened with the test piece mounting support 12 through the test piece mounting fastening assembly 14, and the test piece 11 is connected and fastened with the hydraulic loading assembly 20 through the force loading fastening assembly 13;

[0009] Optionally, the test piece 11 is composed of a rocker arm body 111 and a pair of shoulder bushings 112,

[0010] The test piece mounting support 12 is a forge piece, and has an I-shaped appearance, the upper connecting surface of the test piece mounting support 12 has the same appearance as the middle plate of the rocker arm body 111, and the lower connecting surface is a flange surface, the test piece mounting support 12 is divided into three sections, the middle section is a cylindrical shape, and the upper connecting surface is connected with the lower connecting surface through a through hole and an arc surface of a nut contact part of the test piece mounting fastening assembly 14 to process a lower limit plane, so that the interference between the nut and the arc surface is avoided.

[0011] The force loading fastening assembly 13 is composed of a bolt pair, the bolt light surface size is matched with the inner matching surface of the shoulder bushing 112 through a small interference fit, so that the test is not failed in advance due to the clearance generated in the test process; and the nut is a hexagonal slotted nut, so that the bolt pair is prevented from loosening in the test process.

[0012] Optionally, the hydraulic loading assembly 20 includes a force loading adapter 21, an adapter connector 22, a hydraulic actuator cylinder 23, an actuator cylinder rear support 24,

[0013] The force loading adapter 21 and the test piece 11 are connected through the force loading fastening assembly 13, the force loading adapter 21 and the hydraulic actuator cylinder 23 are connected through the adapter connector 22, the rear end of the hydraulic actuator cylinder 23 is installed on the actuator cylinder rear support 24 through a self-lubricating joint bearing, and the actuator cylinder rear support 24 is connected with the loading fixing assembly 30.

[0014] Optionally, the force loading adapter 21 is a joint bearing structure with a handle, a single lug is used to press the joint bearing inward, the tail of the handle is processed into an external thread, the end of the piston rod of the hydraulic actuator cylinder 23 is provided with a force sensor, so that the output force of the piston rod of the hydraulic cylinder is collected in real time, the external thread of the tail of the handle of the force loading adapter 21 is connected with the thread of the force sensor interface of the hydraulic actuator cylinder 23, the adapter connector 22 has an outer hexagonal shape, an inner thread blind hole is processed in the center of one end surface, and a cylindrical external thread is processed on the other end surface, and the actuator cylinder rear support 24 is a double-insert-ear large connector structure, which is installed on the loading fixing assembly 30, and the installation height of the actuator cylinder rear support 24 is set to ensure that the angle of the hydraulic actuator cylinder 23 applied to the test piece mounting assembly 10 meets the test outline requirements.

[0015] Optionally, the hydraulic actuator cylinder 23 and the actuator cylinder rear support 24 are connected and fastened through an actuator cylinder fastening assembly 25, and the actuator cylinder rear support 24 is connected with the loading fixing assembly 30 through a rear support fastening assembly 26.

[0016] Optionally, the fixed frame assembly 30 is a frame welded structure, which is welded by square steel pipes 32 and steel plates, including a bottom steel plate 31, a reinforcing rib plate 33 and two butt steel plates 34,

[0017] The bottom steel plate 31 is connected with the bottom fixed assembly 50, the square steel pipe 32 is perpendicular to the bottom steel plate 31 and is welded integrally, the reinforcing rib plate 33 is welded around the square steel pipe 32 to stabilize and reinforce the square steel pipe 32, and the two butt steel plates 34 and the rear support of the cylinder 24 are connected through the rear support fastening assembly 26.

[0018] Optionally, the adjustable support assembly 40 is composed of two mutually perpendicular bottom plates 41 and vertical plates 42, the bottom plate 41 is connected and fastened with the fixed assembly 50 at the bottom, the bottom plate 41 is provided with multiple waist-shaped through holes at the four corners of the periphery for adjusting the position of the adjustable support assembly 40 on the bottom fixed assembly 50 to realize fine adjustment of the loading angle, and the vertical plate 42 is provided with a beveled circular arc at the upper end which matches the curved surface of the outer shape of the hydraulic cylinder 23.

[0019] A variable-pitch rocker arm assembly fatigue test system is provided, which comprises the variable-pitch rocker arm assembly fatigue test device of any one of the first aspect, and a servo controller connected with the device, and the hydraulic loading assembly 20 provides loading force and loading angle for the test piece mounting assembly 10 under the control of the servo controller, so that the test piece mounting assembly 10 simulates the real installation state of the test piece on the machine.

[0020] The application has the following beneficial effects:

[0021] The variable-pitch rocker arm assembly fatigue test device provided by the application can simulate the installation structure and load characteristics, and can more truly simulate the installation structure and load characteristics and obtain more accurate and reliable results by using the test piece mounting support to simulate the installation state and using the hydraulic loading assembly to provide the required loading force and loading angle for the test piece. The total test error can be controlled within 3%. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is the isometric view of the application;

[0023] Figure 2 is the top view of the application;

[0024] Figure 3 is the front view of the application;

[0025] Figure 4 is the A-A sectional view of the application;

[0026] Figure 5 is the B-B sectional view of the application. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort should fall into the scope of the protection of the present application.

[0028] The features and illustrative embodiments of various aspects of the present application will be described below in detail. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one of ordinary skill in the art that the present application can be practiced without some of these specific details. The description of the embodiments is merely to provide a better understanding of the present application by showing examples of the present application. The present application is in no way limited to any specific details set forth below and covers any modifications, equivalents, and alternatives falling within the spirit of the present application. In the drawings and the following description, well-known structures and techniques are not shown in order to avoid unnecessary obscurity of the present application.

[0029] It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict, and each embodiment can be referred to and cited by each other.

[0030] The present application will be described in detail below with reference to the drawings and specific embodiments.

[0031] The present application provides a fatigue test device for a variable-pitch rocker arm assembly, referring to Figure 1 The present application comprises a test piece mounting assembly 10, a hydraulic loading assembly 20, a fixed frame assembly 30, an adjustable support assembly 40, and a bottom fixing assembly 50.

[0032] The test piece mounting assembly 10 is composed of a test piece 11, a test piece mounting support 12, a force loading fastening assembly 13, a test piece mounting fastening assembly 14, and a mounting support fastening assembly 15.

[0033] Specifically, referring to Figure 4 The test piece 11 is composed of a rocker arm body 111 and a pair of shoulder bushings 112.

[0034] Specifically, referring to Figure 3The test piece mounting support 12 is a forge piece, and has an I-shaped appearance. The upper connecting surface has the same shape as the plate block of the rocker arm body 111. The lower connecting surface is a flange surface. The middle part is a cylindrical surface, and is connected to the upper and lower connecting surfaces and chamfered. The upper connecting surface has four connecting through holes. The lower connecting surface has six connecting through holes.

[0035] Further, the lower limit plane is processed on the arc surface of the nut contact part of the upper connecting surface, so as to avoid the interference between the nut and the arc surface.

[0036] Specifically, referring to Figure 4 The force loading fastening assembly 13 is composed of a bolt pair, and is used for connecting and fastening the test piece mounting assembly 10 and the hydraulic loading assembly 20.

[0037] Further, the bolt pair of the force loading fastening assembly 13 has a small interference fit between the bolt surface size and the inner fitting surface of the shoulder bush 112.

[0038] Further, the bolt pair of the force loading fastening assembly 13 uses a hexagonal slotted nut, so as to prevent the bolt pair from loosening during the test.

[0039] Specifically, referring to Figure 5 The test piece mounting fastening assembly 14 is composed of a bolt pair, and is used for connecting and fastening the test piece 11 and the test piece mounting support 12.

[0040] Specifically, referring to Figure 3 The mounting support fastening assembly 15 is composed of a bolt, a spring washer and a flat washer, and is used for connecting and fastening the test piece mounting support 12 and the bottom fixing assembly 50.

[0041] The hydraulic loading assembly 20 is composed of a force loading adapter 21, an adapter 22, a hydraulic actuator 23, an actuator rear support 24, an actuator fastening assembly 25 and a rear support fastening assembly 26.

[0042] Specifically, referring to Figure 3 The force loading adapter 21 is a joint bearing structure with a handle. The joint bearing is pressed into the single lug. The handle tail is processed with external threads.

[0043] Further, the handle tail of the force loading adapter 21 is connected to the force sensor interface of the hydraulic actuator 23 through the external thread size.

[0044] Specifically, referring to Figure 3 The adapter 22 has an outer hexagonal shape. An inner threaded blind hole is processed in the center of the one end surface of the adapter. A cylindrical external thread is processed on the other end surface of the adapter, so as to connect the force loading adapter 21 and the hydraulic actuator 23.

[0045] Specifically, referring toFigure 1 The hydraulic actuating cylinder 23 is a finished product, and the rear end is installed on the actuating cylinder rear support 24 through a self-lubricating joint bearing.

[0046] Further, a force sensor is arranged at the piston rod end of the hydraulic actuating cylinder 23 to collect the output force of the hydraulic cylinder piston rod in real time.

[0047] Specifically, referring to Figure 1 The actuating cylinder rear support 24 is a double lug large connector structure, which is installed on the loading fixed assembly 30, and the installation height of the actuating cylinder rear support 24 is set to ensure that the angle at which the hydraulic actuating cylinder 23 is applied to the test piece installation assembly 10 meets the test outline requirements.

[0048] Specifically, referring to Figure 1 The actuating cylinder fastening assembly 25 is composed of a bolt pair, which is used to connect and fasten the hydraulic actuating cylinder 23 and the actuating cylinder rear support 24.

[0049] Specifically, referring to Figure 1 The rear support fastening assembly 26 is composed of a double-thread screw rod, a flat washer and a nut, which is used to connect and fasten the actuating cylinder rear support 24 and the fixed frame assembly 30.

[0050] The fixed frame assembly 30 is a frame welded structure, which is welded integrally by square steel pipes and steel plates. The bottom steel plate 31 is required to be smooth and flat, and the through holes are processed at the four corners of the periphery of the steel plate for connecting the fixed frame assembly 30 and the bottom fixed assembly 50 through a bolt pair. The square steel pipe 32 is perpendicular to the bottom steel plate 31 and is welded integrally. The square steel pipe is stabilized by welding the reinforcing rib plate 33 around the square steel pipe. Two steel plates 34 are selected, and through holes are processed at the four corners of the periphery of the steel plates and are attached to the square steel pipe 32 at an appropriate height, and then a bolt pair is used for connection and fastening.

[0051] The adjustable support assembly 40 is welded integrally by two mutually perpendicular steel plates, and four waist-shaped through holes are processed at the four corners of the periphery of the bottom plate 41 for connecting the adjustable support assembly 40 and the bottom fixed assembly 50 through a bolt, a flat washer and a spring washer. The inclined surface circular arc is processed on the upper end of the vertical plate 42 according to the required angle of the test and the arc surface of the hydraulic actuating cylinder 23, which is used to support the adjusted hydraulic actuating cylinder 23.

[0052] The bottom fixed assembly 50 is composed of a whole thick steel plate and a T-shaped groove through a bolt, a nut, a flat washer and a spring washer, and 6-8 half-waist-shaped grooves are processed at the two sides of the periphery of the thick steel plate. The thick steel plate is fastened and connected with the steel platform at the use site through a T-shaped groove bolt. Threaded holes are processed at the corresponding positions on the thick steel plate for connecting the components in the application through a bolt, a flat washer and a spring washer.

[0053] In one embodiment of the present application, the hydraulic cylinder 23 is loaded by the coordinated loading control system during testing, the installed structure and load characteristics are simulated, the real fatigue performance and weak position of the test piece are obtained through the cumulative cycle test, and the service life of the test piece is determined.

[0054] The above only expresses the embodiments of the present application, the description is more specific and detailed, but it cannot be understood as the limitation of the patent scope. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which belong to the protection scope of the present application. In addition, the parts of the present application not described in detail are all conventional technologies.

Claims

1. A fatigue testing device for variable pitch rocker arm components, characterized in that: The invention comprises a test piece installation assembly (10), a hydraulic loading assembly (20), a fixed frame assembly (30), an adjustable support assembly (40), and a bottom fixing assembly (50). The test piece installation assembly (10), the fixed frame assembly (30), and the adjustable support assembly (40) are fixed on the bottom fixing assembly (50). One end of the hydraulic loading assembly (20) is connected to the test piece installation assembly (10), and the other end is connected to the fixed frame assembly (30). The middle part is clamped on the adjustable support assembly (40); the fixed frame assembly (30) plays a positioning and supporting role for the hydraulic loading assembly (20), and the hydraulic loading assembly (20) provides a loading force and a loading angle to the test piece installation assembly (10), so that the test piece installation assembly (10) simulates the actual installation state of the test piece on the machine.

2. The device according to claim 1, wherein The test piece mounting assembly (10) includes a test piece (11), a test piece mounting support (12), a force loading fastening assembly (13), a test piece mounting fastening assembly (14) and a mounting support fastening assembly (15). The test piece mounting support (12) and the bottom fixing assembly (50) are connected and fastened via a mounting support fastening assembly (15), the test piece (11) and the test piece mounting support (12) are connected and fastened via a test piece mounting fastening assembly (14), and the test piece (11) and the hydraulic loading assembly (20) are connected and fastened via a force loading fastening assembly (13).

3. The device according to claim 2, wherein The test piece (11) consists of a rocker arm body (111) and a pair of shoulder bushings (112). The test piece mounting support (12) is a forging with an I-shaped outer shape. The outer shape of its upper connection surface is consistent with the outer shape of the middle plate of the rocker arm body (111). The lower connection surface is a flange surface. The test piece mounting support (12) is divided into three sections. The middle section is cylindrical and has rounded corners at the contact points with the upper section and the lower section respectively. The arc surface of the contact part of the nut of the test piece mounting fastening assembly (14) is processed with a lower limit plane to avoid interference between the nut and the arc surface. The force loading fastening assembly (13) is composed of a bolt pair. The smooth surface size of the bolt and the inner matching surface of the shoulder bushing (112) adopt a small interference fit to prevent the test from failing prematurely due to the generation of gaps during the test. The nut is a hexagonal slotted nut to prevent the bolt pair from loosening during the test.

4. The device according to claim 2, wherein The hydraulic loading assembly (20) includes a force loading adapter (21), an adapter (22), a hydraulic actuator (23), and an actuator rear support (24). The force loading adapter (21) and the test piece (11) are connected via a force loading fastening assembly (13), the force loading adapter (21) and the hydraulic actuator (23) are connected via an adapter joint (22), the rear end of the hydraulic actuator (23) is mounted on a rear actuator support (24) via a self-lubricating spherical bearing, and the rear actuator support (24) is connected to the loading fixing assembly (30).

5. The device according to claim 4, characterized in that The force loading adapter (21) is a spherical bearing structure with a handle, a spherical bearing is press-fitted into a single ear piece, an external thread is processed at the tail of the handle, a force sensor is provided at the end of the piston rod of the hydraulic cylinder (23), and the output force of the hydraulic cylinder piston rod is collected in real time. The external thread at the tail of the handle in the force loading adapter (21) is threadedly connected to the interface of the force sensor in the hydraulic cylinder (23); the adapter (22) is in an external hexagonal shape, an internal thread blind hole is processed at the center of one end face, and a cylindrical external thread is processed at the other end face; the rear support (24) of the cylinder is a double-plug-ear large joint structure, which is installed on the loading fixing assembly (30), and the setting of the installation height of the rear support (24) of the cylinder ensures that the angle applied by the hydraulic cylinder (23) to the test piece installation assembly (10) meets the requirements of the test outline.

6. The device according to claim 4, characterized in that The hydraulic actuator (23) and the actuator rear support (24) are connected and fastened via an actuator fastening assembly (25); the actuator rear support (24) and the loading and fixing assembly (30) are connected via a rear support fastening assembly (26).

7. The device according to claim 6, characterized in that The fixed frame assembly (30) is a frame welding structure, which is welded into one by a square steel tube (32) and a steel plate. The steel plate includes a bottom steel plate (31), a reinforcing rib plate (33) and two butt steel plates (34). The bottom steel plate (31) is connected to the bottom fixing assembly (50), the square steel tube (32) is perpendicular to the bottom steel plate (31) and welded together, and the reinforcing ribs (33) are welded around the square steel tube (32) to reinforce the stability of the square steel tube (32); the two butt joint steel plates (34) and the rear support (24) of the actuator cylinder are connected through the rear support fastening assembly (26), and the butt joint steel plates (34) and the square steel tube (32) are fastened together.

8. The device according to claim 7, wherein The adjustable support assembly (40) is composed of two mutually perpendicular bottom plates (41) and a vertical plate (42). The bottom of the bottom plate (41) is connected and fastened to the fixed assembly (50). A plurality of waist-shaped through holes are provided at the four corners of the bottom plate (41) for adjusting the position of the adjustable support assembly (40) on the bottom fixed assembly (50) to achieve fine adjustment of the loading angle. The upper end of the vertical plate (42) is provided with an inclined arc that matches the outer arc surface of the hydraulic actuator cylinder (23).

9. A variable pitch rocker arm assembly fatigue test system, characterized in that: The invention comprises a variable pitch rocker arm assembly fatigue test device as described in any one of claims 1 to 8, and a servo controller connected to the device, wherein the hydraulic loading component (20) provides a loading force and a loading angle to the test piece installation component (10) through hydraulic pressure under the control of the servo controller, so that the test piece installation component (10) simulates the actual installation state of the test piece on the machine.

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