A testing device for the release degree of the tightening torque at the root of a propeller and its testing method

Abstract

The present invention discloses a test device and a test method for the release degree of the tightening torque at the root of a propeller. The device includes a test bench, an adapter flange, a centrifugal load actuator, a first dial indicator, a second dial indicator and a centrifugal load loading system. The adapter flange is fixedly connected to the bottom of the propeller housing. The centrifugal load actuator is fixedly connected to the propeller blade simulation and is located outside the test bench. The first dial indicator is fixed on the test bench and corresponds to one end of the cuff of the propeller housing. The test head of the first dial indicator abuts against the end face of the cuff of the propeller housing to measure the displacement change in the axial direction of the propeller housing. The second dial indicator is fixed on the test bench and corresponds to the position of the propeller sleeve away from the propeller housing. The test head of the second dial indicator abuts against the end face of the propeller sleeve to measure the axial displacement change of the propeller sleeve. The centrifugal load loading system is connected to the centrifugal load actuator to control the loading of the centrifugal load actuator. The structure of the present invention is simple and can measure the release of the tightening torque at the root of the propeller.

Description

Technical Field

[0001] The present invention relates to the technical field of aerospace propellers, and particularly relates to a test device and a test method for the release degree of the tightening torque at the root of a propeller. Background Art

[0002] For a variable-pitch composite propeller, the blade is connected to the composite blade through a thread inside the blade sleeve, and the outside of the sleeve is connected to the blade housing through a bearing. During the assembly of the propeller, in order to eliminate the assembly clearance in the axial direction of the blade axis, the sleeve nut is used to pre-tighten the sleeve. The pre-tightening force of the sleeve nut directly acts on the bearing. When the propeller rotates, the centrifugal load of the blade is transmitted through the sleeve thread. The deformation of the sleeve due to the force will release the pre-tightening force of the sleeve nut, thereby reducing the variable-pitch resistance of the bearing. If the pre-tightening force is too large, the rotational resistance during the variable pitch of the propeller will increase. If the pre-tightening force is too small, the axial clearance during the assembly of the propeller cannot be eliminated.

[0003] Therefore, how to provide a test device for the release degree of the tightening torque at the root of a propeller, which can study the release degree of the pre-tightening force of the sleeve nut of this type of propeller under the action of the centrifugal load of the blade and judge whether the value of the pre-tightening force of the sleeve nut of this type of propeller is reasonable, is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a test device and a test method for the release degree of the tightening torque at the root of a propeller, which can measure whether the pre-tightening force at the root of the propeller is reasonable and facilitate the variable pitch during the operation of the propeller.

[0005] To achieve the above object, the present invention adopts the following technical solution: A test device for the release degree of the tightening torque at the root of a propeller, the test propeller includes a blade simulation member, a sleeve and a blade housing. The sleeve is fixedly connected to the root of the blade simulation member by a thread; the outer circumference of the sleeve is rotatably connected to the blade housing through a bearing and a pre-tightening force is applied by a sleeve nut to eliminate the assembly clearance in the axial direction of the blade simulation member. The contact surface between the sleeve nut and the sleeve is the tightening torque acting surface, which includes a test bench frame, a transition flange, a centrifugal load actuator, a first dial indicator, a second dial indicator and a centrifugal load loading system. The transition flange is fixedly connected to the bottom of the blade housing. The centrifugal load actuator is fixedly connected to the blade simulation member and is located outside the test bench frame. The first dial indicator is fixed on the test bench frame and corresponds to one end of the blade housing cuff. The test head of the first dial indicator abuts against the end face of the blade housing cuff to measure the displacement change in the axial direction of the blade housing. The second dial indicator is fixed on the test bench frame and corresponds to the position of the sleeve away from the blade housing. The test head of the second dial indicator abuts against the end face of the sleeve to measure the axial displacement change of the sleeve; the centrifugal load loading system is connected to the centrifugal load actuator to control the loading of the centrifugal load actuator.

[0006] The beneficial effects of the present invention are as follows: A test bench is provided. The propeller hub is connected to the test bench through an adapter flange. The blade simulation component is connected to the propeller hub through a bushing. The centrifugal load actuator is connected to the blade simulation component. The centrifugal load loading system is connected to the centrifugal load actuator to control the loading of the centrifugal load actuator, thereby realizing the adjustment of the centrifugal load of the blade simulation component. By simulating the working environment of the actual blade with the blade simulation component, the blade simulation component is rotationally connected to the propeller hub through a bushing, which is convenient for torque conversion. When the bushing is connected to the propeller hub, an axial pre-tightening force is applied through a bushing nut to eliminate the axial assembly clearance of the propeller. The axial displacement of the propeller hub is measured by a first dial indicator, and the axial displacement of the bushing is measured by a second dial indicator. During loading, observe the numerical changes of the second dial indicator and the first dial indicator. The same numerical change indicates that when under this centrifugal load, the axial displacement change amounts of the propeller hub and the bushing are consistent, and the pre-tightening force of the bushing nut is not released. Reduce the tightening torque value of the bushing nut and continue the test until the near tightening torque value of the bushing nut is determined.

[0007] Preferably, the contact position between the end face of the propeller hub cuff and the first dial indicator is the first measurement point, and a first measurement block is fixedly provided at the first measurement point. The contact position between one end of the bushing and the second dial indicator is the second measurement point, and a second measurement block is fixedly provided at the second measurement point.

[0008] Preferably, both the first measurement block and the second measurement block are rectangular blocks, which are fixedly bonded to the end face of the propeller hub cuff and the end face of the bushing respectively. The measurement surfaces of the first measurement block and the second measurement block are smooth and flat.

[0009] Preferably, the blade simulation component includes a blade root, a blade body simulation component and a clamping plate. The blade body simulation component is fixedly connected to one end of the blade root. The blade body simulation component has a predetermined axial distance. The clamping plates are grouped in pairs and are respectively fixedly connected to the top surface and the bottom surface of the blade body simulation component through long bolts. The centrifugal load actuator is fixedly connected to the blade simulation component.

[0010] Preferably, the axial length of the blade body simulation component is 30 - 50 dm.

[0011] The present invention also discloses a test method for the release degree of the tightening torque at the root of the propeller, which includes the following steps:

[0012] Step 1: Fix the adapter flange to the bottom of the propeller hub. The propeller hub is connected to the test bench through the adapter flange. Then assemble the blade simulation component to the propeller hub through the bushing. Fix the centrifugal load actuator to the blade simulation component. Initially tighten the bushing nut to make it have a certain tightening torque value.

[0013] Step 2: Connect and debug the centrifugal load loading system to the centrifugal load actuator.

[0014] Step 3: Fix and install a first dial indicator at one end of the propeller sleeve nut on the test bench, such that the test head of the first dial indicator abuts against the end face of the propeller housing cuff to measure the displacement change in the axial direction of the propeller housing; fix and install a second dial indicator at a position on the test bench corresponding to the end of the propeller sleeve away from the propeller housing, such that the test head of the second dial indicator abuts against the end face of the propeller sleeve to measure the axial displacement change of the propeller sleeve.

[0015] Step 4: Start the centrifugal load loading system to apply a certain centrifugal load to the blade simulation; observe the change in the reading of the first dial indicator and record it, and observe the change in the reading of the second dial indicator and record it.

[0016] Step 5: On the basis of Step 4, apply a certain centrifugal load, record the change in the reading of the first dial indicator and the change in the reading of the second dial indicator, plot the displacement-load change curve, and compare whether the change value of the reading of the first dial indicator after loading is consistent with the change value of the reading of the second dial indicator after loading. If they are consistent, the tightening torque of the propeller sleeve nut has not been released.

[0017] Step 6: Reduce the tightening torque value of the propeller sleeve nut and repeat Step 5 to obtain the critical tightening torque value of the propeller sleeve nut. Description of the Drawings

[0018] Figure 1 It is the overall schematic diagram of a test device for measuring the release degree of the tightening torque at the root of a propeller according to the present invention.

[0019] Figure 2 It is the partial schematic diagram of a test device for measuring the release degree of the tightening torque at the root of a propeller according to the present invention.

[0020] Figure 3 It is the enlarged schematic diagram at position A of a test device for measuring the release degree of the tightening torque at the root of a propeller according to the present invention.

[0021] 1 Blade simulation, 101 Propeller root, 102 Blade body simulation, 103 Clamping plate, 2 Propeller sleeve, 3 Propeller housing, 4 Bearing, 401 Bearing 1, 402 Bearing 2, 5 Propeller sleeve nut, 6 Test bench, 7 Adapter flange, 8 First measurement point, 9 Second measurement point, 10 Tightening torque action surface, 11 Centrifugal load actuator, 12 First dial indicator, 13 Second dial indicator, 14 First measurement block, 15 Second measurement block. Detailed Embodiments

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] Referring to the attached drawings of the present invention Figures 1 to 3 , according to an embodiment of the present invention, a test device for the release degree of the tightening torque at the root of a propeller, the test propeller includes a blade simulation part 1, a propeller sleeve 2 and a propeller housing 3. The propeller sleeve 2 is threadedly fixed to the root of the blade simulation part 1; the outer periphery of the propeller sleeve 2 is rotatably connected to the propeller housing 3 through a bearing 4 and a pre-tightening force is applied through a propeller sleeve nut 5 to eliminate the assembly clearance in the axial direction of the blade simulation part. The contact surface between the propeller sleeve nut 5 and the propeller sleeve is the tightening torque acting surface 10, which includes a test bench 6, a transition flange 7, a centrifugal load actuator 11, a first dial indicator 12, a second dial indicator 13 and a centrifugal load loading system. The transition flange 7 is fixedly connected to the bottom of the propeller housing 3. The centrifugal load actuator is fixedly connected to the blade simulation part 1 and is located outside the test bench 6. The first dial indicator is fixed on the test bench 6 and corresponds to one end of the cuff of the propeller housing. The test head of the first dial indicator abuts against the end face of the cuff of the propeller housing to measure the displacement change in the axial direction of the propeller housing. The second dial indicator is fixed on the test bench 6 and corresponds to the position of the propeller sleeve 2 away from the propeller housing 3. The test head of the second dial indicator abuts against the end face of the propeller sleeve to measure the axial displacement change of the propeller sleeve; the centrifugal load loading system is connected to the centrifugal load actuator to control the loading of the centrifugal load actuator.

[0024] In some specific embodiments, the contact position between the end face of the cuff of the propeller housing 3 and the first dial indicator is the first measurement point 8, and a first measurement block 14 is fixedly provided at the first measurement point 8. The contact position between one end of the propeller sleeve 2 and the second dial indicator is the second measurement point 9, and a second measurement block 15 is fixedly provided at the second measurement point 9. Since the end faces of the cuffs of the propeller housing and the propeller sleeve are relatively narrow and small, it is easy for the dial indicator head to slip out of the measurement end face. Therefore, measurement blocks are respectively pasted at the end face of the cuff of the propeller housing (the first measurement point) and the end face of the propeller sleeve (the second measurement point) to facilitate measuring the axial displacement of the measurement blocks. It plays a role in magnifying the measurement point.

[0025] In some other specific embodiments, both the first measurement block 14 and the second measurement block 15 are rectangular blocks, which are fixedly bonded to the end face of the cuff of the propeller housing and the end face of the propeller sleeve respectively. The measurement surfaces of the first measurement block and the second measurement block are smooth and flat. To ensure the measurement accuracy.

[0026] In some other embodiments, the blade simulation member 1 includes a blade root 101, a blade body simulation member 102 and a clamping plate 103. The blade body simulation member 102 is fixedly connected to one end of the blade root 101. The blade body simulation member 102 has a predetermined axial distance. The clamping plates 103 are grouped in pairs and are respectively fixedly connected to the top surface and the bottom surface of the blade body simulation member 102 through long bolts. The blade simulation member is fixedly connected to the centrifugal load actuator. The weight condition of the blade is simulated through the connection of the blade body simulation member and the clamping plates, replacing the blade test. Moreover, the blade body simulation member reduces the test space and is convenient for measurement.

[0027] Specifically, the axial length of the blade body simulation member 102 is 30 - 50 dm, which is convenient for measurement.

[0028] The present invention discloses a test method for the release degree of the tightening torque of a propeller root, which includes the following steps:

[0029] Step 1: First, fixedly connect the propeller hub to the bottom of the propeller housing through a transfer flange on the test bench, and then assemble the blade simulation member with the propeller housing through a propeller sleeve; fixedly connect the centrifugal load actuator to the blade simulation member, and initially tighten the propeller sleeve nut to make it have a certain tightening torque value;

[0030] Step 2: Connect and debug the centrifugal load loading system with the centrifugal load actuator;

[0031] Step 3: Fix and install a first dial indicator at one end of the propeller sleeve nut corresponding to the test bench, so that the test head of the first dial indicator abuts against the end face of the propeller housing cuff to test the displacement change amount in the axial direction of the propeller housing; fix and install a second dial indicator at a position corresponding to the end of the propeller sleeve away from the propeller housing on the test bench, so that the test head of the second dial indicator abuts against the end face of the propeller sleeve to measure the axial displacement change amount of the propeller sleeve;

[0032] Step 4: Start the centrifugal load loading system to make the blade simulation member have a certain centrifugal load; observe the reading change of the first dial indicator and record it, observe the reading change of the second dial indicator and record it;

[0033] Step 5: On the basis of Step 4, apply a certain centrifugal load, record the reading change of the first dial indicator, record the reading change of the second dial indicator, draw a displacement-load change curve, and compare whether the reading change value of the first dial indicator after loading is consistent with the reading change value of the second dial indicator after loading. If they are consistent, the tightening torque of the propeller sleeve nut is not released;

[0034] Step 6: Reduce the tightening torque value of the propeller sleeve nut, and repeat Step 5 to obtain the critical tightening torque value of the propeller sleeve nut.

[0035] In the present invention, the dial head is attached to the measuring block. An axial centrifugal load is applied to the blade simulation component. With the action of the centrifugal load, the blade housing and the blade sleeve will generate an axial displacement in the direction of the centrifugal load. The change in displacement is recorded by a micrometer, and a load-displacement curve is plotted. Through the curve graph, it can be determined whether the tightening torque of the blade sleeve nut is completely released under the specified centrifugal load of the blade.

[0036] The centrifugal load is Fc.

[0037] During specific testing, the propeller is assembled as required. A tightening torque is preset on the acting surface between the blade sleeve nut and the blade sleeve. The tightening torque causes the blade simulation component to move outward along the blade axis (in the direction of the centrifugal load), eliminating the axial assembly clearance, and making the bearing one in close contact with the blade housing, and the bearing two in close contact with the blade housing and the blade sleeve. The propeller is fixed on the test bench. A first measuring block is pasted at the first measuring point, and a second measuring block is bonded at the second measuring point. The test bench fixes the first micrometer and the second micrometer. The centrifugal load actuator is used to apply the centrifugal load to the propeller root simulation component in stages, and the displacements at the first measuring point and the second measuring point are recorded.

[0038] The centrifugal load of the blade simulation component is borne by the threads at the root of the blade sleeve. The threads at the root of the blade sleeve are distributed in the axial direction between the mating surface of the bearing one 401 and the blade sleeve nut. The centrifugal load causes the blade sleeve to generate an axial displacement in the direction of the centrifugal load. Therefore, the displacement of the blade sleeve (the second measuring point) is the sum of the displacement of the part of the blade sleeve of the bearing one and the displacement generated by the mating surface of the blade sleeve nut; the blade sleeve transmits the centrifugal load to the blade housing through the bearing one, and the blade housing generates an axial displacement in the direction of the centrifugal load. According to Figure 1 the structural relationship, the axial displacement generated by the part of the bearing of the blade sleeve is consistent with the axial displacement of the blade housing.

[0039] The bearing two 402 is used to bear the pre-tightening axial acting force between the other end of the blade sleeve nut and the blade housing, so that the blade sleeve nut can rotate normally.

[0040] That is to say, when the pre-tightening force is too large, the axial displacements of the blade sleeve acting on the blade housing through the bearing one 402 are the same, and the change in the displacement increment between the first measuring point and the second measuring point is the same. When the pre-tightening force is too small, the difference in the displacement change between the first measuring point and the second measuring point is the change in the relative displacement of the contact surface between the blade sleeve and the blade sleeve nut. Furthermore, the effect of the pre-tightening torque can be judged.

[0041] According to the test data, compare the displacement increments of each level of load at two measurement points. If the displacement increments are consistent under the specified centrifugal load, it indicates that the pre-tightening force of the hub nut is not released under this centrifugal load. Reduce the tightening torque value of the hub nut and continue to test using the test device and method of the present invention to determine the critical tightening torque value of the hub nut in such a propeller root structure. The critical tightening torque value can not only ensure that the axial assembly clearance can be eliminated during the assembly of the propeller, but also will not increase the resistance of the blade rotation due to an excessive value.

[0042] For the devices and usage methods disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For related parts, refer to the description in the method section.

[0043] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A test device for the release degree of the tightening torque at the root of a propeller. The propeller includes a blade simulation part (1), a propeller sleeve (2) and a propeller housing (3). The propeller sleeve (2) is fixedly connected to the root of the blade simulation part (1) by threads. The outer circumference of the propeller sleeve (2) is rotatably connected to the propeller housing (3) through a bearing (4), and a pre-tightening force is applied through a propeller sleeve nut (5) to eliminate the assembly clearance in the axial direction of the blade simulation part. The contact surface between the propeller sleeve nut (5) and the propeller sleeve is the tightening torque acting surface (10), and it is characterized in that, It includes a test bench (6), an adapter flange (7), a centrifugal load actuator (11), a first dial indicator (12), a second dial indicator (13) and a centrifugal load loading system. The adapter flange (7) is fixedly connected to the bottom of the propeller housing (3). The centrifugal load actuator is fixedly connected to the propeller blade simulation part (1) and is located outside the test bench (6). The first dial indicator is fixed on the test bench (6) and corresponds to one end of the cuff of the propeller housing (3). The test head of the first dial indicator abuts against the end face of the cuff of the propeller housing to measure the displacement change in the axial direction of the propeller housing. The second dial indicator is fixed on the test bench (6) and corresponds to the position of the propeller sleeve (2) far from the propeller housing (3). The test head of the second dial indicator abuts against the end face of the propeller sleeve (2) to measure the axial displacement change of the propeller sleeve (2); The centrifugal load loading system is connected to the centrifugal load actuator to control the loading of the centrifugal load.

2. The testing device for the release degree of the tightening torque at the root of a propeller according to claim 1, characterized in that, The contact position between the end face of the cuff of the propeller housing (3) and the first dial indicator is the first measurement point (8). A first measurement block (14) is fixedly provided at the first measurement point (8). The contact position between one end of the propeller sleeve (2) and the second dial indicator is the second measurement point (9). A second measurement block (15) is fixedly provided at the second measurement point (9).

3. The propeller root tightening torque release degree testing device according to claim 2, characterized in that, Both the first measurement block (14) and the second measurement block (15) are rectangular blocks, which are fixedly bonded to the end face of the cuff of the propeller housing and the end face of the propeller sleeve respectively. The measurement surfaces of the first measurement block and the second measurement block are smooth and flat.

4. A test device for the release degree of the tightening torque at the root of a propeller, characterized in that, The propeller blade simulation part (1) includes a blade root (101), a blade body simulation part (102) and a clamping plate (103). The blade body simulation part (102) is fixedly connected to one end of the blade root (101). The blade body simulation part (102) has a predetermined axial distance. The clamping plates (103) are grouped in pairs and are respectively fixedly connected to the top surface and the bottom surface of the blade body simulation part (102) by long bolts. The centrifugal load actuator is fixedly connected to the propeller blade simulation part.

5. A testing device for the release degree of the tightening torque at the root of a propeller, according to claim 4, characterized in that The axial length of the blade body simulation part (102) is 30 - 50 dm.

6. A test method for the degree of release of the tightening torque at the root of a propeller, which uses the test device described in any one of claims 1-5, characterized in that, It includes the following steps: Step 1: Fix the adapter flange to the bottom of the propeller housing. The propeller housing is connected to the test bench through the adapter flange. Then assemble the propeller blade simulation part with the propeller housing through the propeller sleeve; Fix the centrifugal load actuator to the propeller blade simulation part and initially tighten the propeller sleeve nut to make it have a certain tightening torque value; Step 2: Connect and debug the centrifugal load loading system with the centrifugal load actuator; Step 3: Fix and install a first dial indicator at one end of the test bench corresponding to the propeller sleeve nut, so that the test head of the first dial indicator abuts against the end face of the cuff of the propeller housing to measure the displacement change in the axial direction of the propeller housing; Fix and install a second dial indicator at the position of the test bench corresponding to the propeller sleeve far from the propeller housing, so that the test head of the second dial indicator abuts against the end face of the propeller sleeve to measure the axial displacement change of the propeller sleeve; Step 4: Start the centrifugal load loading system to apply a certain centrifugal load to the blade simulation component; observe the reading changes of the first dial indicator and record them, and observe the reading changes of the second dial indicator and record them; Step 5: Based on Step 4, apply a certain additional centrifugal load, record the reading changes of the first dial indicator and the second dial indicator, plot the displacement-load change curve, and compare whether the change values of the readings of the first dial indicator after loading are consistent with those of the second dial indicator after loading. If they are consistent, the tightening torque of the bushing nut has not been released; Step 6: Reduce the tightening torque value of the bushing nut and repeat Step 5 to obtain the critical tightening torque value of the bushing nut.

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