A friction coefficient testing device and method under large load centrifugal force

Abstract

The present invention provides a friction coefficient testing device and method under large load centrifugal force, including: a test bench bottom plate, a fixed support, and a swing and centrifugal force loading mechanism; the fixed support includes a connecting bottom plate and a fixed plate, and the connecting bottom plate is fixed on the test bench bottom plate; the top of the main propeller central part arm dummy is installed on the top of one side of the fixed plate, and its top is limited in a limiting boss set on one side of the fixed plate; the swing loading mechanism is set along the swing force loading direction, clamps the elastic bearing dummy, and presses it against the outer end face of the main propeller central part arm dummy; the double fork ears of the centrifugal force loading mechanism pass through the rectangular through hole of the fixed plate, and presses the elastic bearing dummy on the outer end face of the main propeller central part arm dummy. The technical solution of the embodiment of the present invention solves the problem that the friction coefficient between the elastic bearing dummy and the mounting surface of the main propeller central part arm in the fatigue test of the existing main propeller central part cannot be measured at present.

Description

Technical Field

[0001] The present invention relates to, but is not limited to, the technical field of friction coefficient testing of helicopter central component fatigue tests, and in particular to a friction coefficient testing device and method under high load centrifugal force. Background Art

[0002] The main rotor center piece of the ball-flexible rotor helicopter is equipped with an elastic bearing on each arm through two positioning bolts, and the centrifugal force, swing force and flapping force transmitted by the main rotor blade are transmitted to the main rotor center piece through the elastic bearing. Among them, the centrifugal force acts on the mounting surface of the elastic bearing and the center piece arm as a large load centrifugal force, and the friction force generated by the centrifugal force on the above mounting surface is used to resist the swing force perpendicular to the centrifugal force, so that the positioning bolts do not bear the shear force caused by the swing force.

[0003] At present, when fatigue testing is performed on the main rotor centerpiece, an elastic bearing dummy and a positioning bolt dummy need to be installed on each arm of the main rotor centerpiece. After the fatigue test of the current main rotor centerpiece is completed, the positioning bolt dummy is basically not damaged (except for abnormal conditions); however, during the fatigue test of a certain type of main rotor centerpiece, the positioning bolt dummy frequently breaks, causing the elastic bearing dummy to shift along the swing force loading direction, which results in the fatigue test being forced to be interrupted. After excluding other possible causes of fatigue test failure, it is suspected that the friction coefficient between the elastic bearing dummy and the mounting surface of the main rotor centerpiece arm is insufficient, causing the positioning bolt dummy to bear unnecessary shear force. Therefore, it is necessary to further test and confirm the friction coefficient between the elastic bearing dummy and the mounting surface of the main rotor centerpiece arm in this type of fatigue test.

[0004] Through searching the data, no relevant test plan and test equipment for the friction coefficient under large load centrifugal force have been found so far. Summary of the invention

[0005] The purpose of the present invention is: the present invention provides a friction coefficient testing device and method under high load centrifugal force to solve the problem that the friction coefficient between the elastic bearing dummy and the main propeller center piece arm mounting surface cannot be measured in the existing main propeller center piece fatigue test.

[0006] The technical solution of the present invention is: the present invention provides a friction coefficient test device under large load centrifugal force, comprising: a test bench bottom plate 1, a fixed support 2, a fixing screw 3, a first fixing screw 9-1, and a shimmy loading mechanism and a centrifugal force loading mechanism;

[0007] The fixed support 2 is configured as an inverted T-shaped structure, including: a connecting base plate and a fixing plate arranged perpendicular to each other; the connecting base plate is fixedly mounted on the test bench base plate 1 by fixing screws 3, two rectangular through holes are symmetrically arranged in the middle of the fixing plate, and a first limiting boss is arranged on the top of one side of the fixing plate;

[0008] The top of the main propeller central part arm dummy B is fixedly installed on the top of one side of the fixing plate by the first fixing screw 9-1, and its top highest position is limited to the inner side of the first limiting boss; the swing loading mechanism is arranged along the swing force loading direction, and is used to clamp the elastic bearing dummy A, and press the elastic bearing dummy A against the outer end face of the main propeller central part arm dummy B; the double fork ears on both sides of the centrifugal force loading mechanism pass through the two rectangular through holes, and press the elastic bearing dummy A against the outer end face of the main propeller central part arm dummy B, and the centrifugal force loading mechanism is arranged along the centrifugal force loading direction.

[0009] Optionally, in the friction coefficient testing device under large load centrifugal force as described above, the oscillation loading mechanism includes: a joint baffle 4, a oscillation clamping joint 5, a clamping screw 5-1, a baffle fixing screw 6, and a second fixing screw 9-2;

[0010] The joint baffle 4 is fixedly mounted on the bottom of the fixing plate by a second fixing screw 9-2, and the second fixing screw 9-2 fixes the bottom of the main propeller central arm dummy B to one side end of the fixing plate;

[0011] The swing clamping joint 5 is configured as a U-shaped groove structure, with its bottom end face placed on the upper end face of the joint baffle 4, and the two side ends of the U-shaped groove structure are symmetrically arranged along the swing force loading direction, and threaded holes are symmetrically arranged at the lower ends of both sides of the U-shaped groove structure. The elastic bearing dummy A nested in the inner side of the U-shaped groove is clamped and positioned by the clamping screw 5-1, and one side of the elastic bearing dummy A is pressed against the outer side of the main propeller central part support arm dummy B.

[0012] Optionally, in the friction coefficient testing device under large load centrifugal force as described above, the oscillation loading mechanism further comprises: a oscillation loading handle 10, a oscillation loading bolt 11;

[0013] Symmetrical through holes are provided at both side ends of the U-shaped groove structure, which are used to connect to one end of the swing loading handle 10 through a swing loading bolt 11 passing through the through hole. The other end of the swing loading handle 10 is connected to a swing loading actuator, and a swing force is applied to the elastic bearing dummy A through the swing loading handle 10.

[0014] Optionally, in the friction coefficient testing device under high load centrifugal force as described above,

[0015] A positioning boss is arranged at the bottom of the inner side of the U-shaped groove of the U-shaped groove structure, which is used to be embedded in the inner groove of the elastic bearing dummy A.

[0016] Optionally, in the friction coefficient testing device under large load centrifugal force as described above, the centrifugal force loading mechanism includes: a right-angle baffle 7, a centrifugal force clamping joint 8, a second fixing screw 9-2, a shimmy loading bolt 11, a centrifugal force loading joint 12, and a centrifugal force loading bolt 13;

[0017] The centrifugal force clamping joint 8 is configured as a U-shaped double-fork ear structure, which is used to pass through the two rectangular through holes on the fixing plate and is symmetrically arranged along the centrifugal force loading direction;

[0018] The inner end face of the U-shaped portion of the U-shaped double-fork ear structure abuts against the end face of the opposite side of the elastic bearing dummy A, and a second limiting boss is provided on the top of the inner end face of the U-shaped portion to limit the highest position of the top of the elastic bearing dummy A. A threaded hole is provided on the bottom end face of the U-shaped portion, and one side plate of the right-angle baffle 7 is fixedly connected to the bottom end of the U-shaped portion by screws or bolts, and the elastic bearing dummy A is positioned and fixed along the swing force direction by the second limiting boss and the other side plate of the right-angle baffle 7;

[0019] Symmetrical through holes are provided at both side ends of the U-shaped double-fork ear structure for connecting the centrifugal force loading joint 12 via the centrifugal force loading bolts 13 penetrating the through holes.

[0020] Optionally, in the friction coefficient testing device under large load centrifugal force as described above, the centrifugal force loading mechanism further includes: a centrifugal force loading steel cable 14 and a loading pin 15;

[0021] The centrifugal force loading joint 12 has a single ear piece with a through hole at one end, which is connected to the U-shaped double-fork ear end of the centrifugal force clamping joint 8 through a centrifugal force loading bolt 13, and the other end is a double ear piece with a through hole, which is connected to one end of a centrifugal force loading cable 14 through a loading pin 15 passing through the through hole. The other end of the centrifugal force loading cable 14 applies centrifugal force to the elastic bearing dummy A by connecting a centrifugal force loading actuator.

[0022] Among them, the axis of the centrifugal force loading steel cable 14 coincides with the centrifugal force loading direction, so that the applied centrifugal force is accurately transmitted along the centrifugal force loading steel cable 14 to the contact surface between the elastic bearing dummy A and the main propeller central part arm dummy B, thereby generating friction on the contact surface.

[0023] The embodiment of the present invention further provides a friction coefficient testing method under high load centrifugal force, using the friction coefficient testing device under high load centrifugal force as described in any one of the above items to measure the friction coefficient of the contact surface between the elastic bearing dummy A and the main propeller central part arm dummy B; the friction coefficient testing method includes:

[0024] Step 1, continuously applying a centrifugal force of a specified load to the elastic bearing dummy A through a centrifugal force loading mechanism;

[0025] Step 2, in the process of continuously applying centrifugal force, a slowly increasing oscillating force is applied to the elastic bearing dummy A through the oscillating loading mechanism, so that friction is generated between the contact surface of the elastic bearing dummy A and the main propeller central component support arm dummy B; wherein the oscillating force loading direction is perpendicular to the centrifugal force loading direction;

[0026] Step 3: When the applied oscillating force increases to a critical mutation value, stop loading and record the maximum oscillating force value.

[0027] Optionally, the friction coefficient test method under high load centrifugal force as described above further includes:

[0028] Step 4: Calculate the friction coefficient according to the maximum swing force value and the centrifugal force value of the fixed load: centrifugal force value / maximum swing force value.

[0029] Optionally, the friction coefficient test method under high load centrifugal force as described above further includes:

[0030] Step 5, by changing the materials of the elastic bearing dummy A and the main propeller central arm dummy B, and the roughness of the mounting surface, the friction coefficient of different combination test pieces is tested.

[0031] Beneficial technical effects of the present invention:

[0032] The friction coefficient test device and method under large load centrifugal force provided by the present invention can not only realize the real simulation of the assembly boundary conditions and loading conditions during the fatigue test of the main propeller center piece, but also can truly simulate the materials, installation surface roughness, and conditions of bearing large centrifugal force and swing force of the main propeller center piece support arm and the elastic bearing dummy; it can also realize the friction coefficient test of the installation surface of the main propeller center piece support arm and the elastic bearing dummy. In addition, the friction coefficient test device provided by the embodiment of the present invention has a coordinated structure, stable loading, and high reliability of test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0034] Figure 1 A schematic diagram of the overall structure of a friction coefficient testing device under a large load centrifugal force provided by an embodiment of the present invention;

[0035] Figure 2 for Figure 1 A cross-sectional view of the AA surface of the friction coefficient testing device under a large load centrifugal force provided by the illustrated embodiment;

[0036] Figure 3 for Figure 1 The illustrated embodiment provides a cross-sectional view of the BB surface of a friction coefficient testing device under a large load centrifugal force. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0038] It has been explained in the above background technology that during the fatigue test of a certain type of main propeller center component known in the prior art, the positioning bolt dummy frequently broke, causing the elastic bearing dummy to shift along the swing force loading direction; and it is considered that the above phenomenon is caused by the insufficient friction coefficient between the elastic bearing dummy and the mounting surface of the main propeller center component arm, which causes the positioning bolt dummy to bear unnecessary shear force.

[0039] In order to solve the problem of how to confirm the friction coefficient between the main propeller central part support arm and the elastic bearing dummy mounting surface, an embodiment of the present invention provides a friction coefficient testing device and method under high-load centrifugal force; and it should be noted that, at present, there is no test device in China similar to the friction coefficient testing device under high-load centrifugal force proposed in the embodiment of the present invention, so the test method provided in the embodiment of the present invention cannot be performed; and no relevant foreign public documents have been retrieved.

[0040] The present invention provides the following specific embodiments which can be combined with each other. The same or similar concepts or processes may not be described in detail in some embodiments.

[0041] Figure 1 The present invention provides a schematic diagram of the overall structure of a friction coefficient testing device under a large load centrifugal force. Figure 1 Specifically, it is a top view of the friction coefficient testing device. Figure 2 for Figure 1 The cross-sectional view of the AA surface of the friction coefficient test device under large load centrifugal force provided by the illustrated embodiment, Figure 3 for Figure 1 The illustrated embodiment provides a cross-sectional view of the BB surface of a friction coefficient testing device under a large load centrifugal force.

[0042] Combination Figures 1 to 3As shown, the basic structure of the friction coefficient testing device under large load centrifugal force provided by an embodiment of the present invention may include: a test bench base plate 1, a fixed support 2, a fixing screw 3, a first fixing screw 9-1, and a swing loading mechanism and a centrifugal force loading mechanism;.

[0043] Reference Figures 1 to 3 In the structure of the friction coefficient testing device shown, the fixed support 2 is set as an inverted T-shaped structure, specifically including: a connecting base plate and a fixing plate arranged perpendicular to each other; the connecting base plate is fixedly installed on the test bench base plate 1 by fixing screws 3, and two rectangular through holes are symmetrically arranged in the middle of the fixing plate, and a first limiting boss is arranged on the top of one side of the fixing plate.

[0044] The top of the main propeller central arm dummy B in the embodiment of the present invention is fixedly mounted on the top of one side of the fixing plate by a first fixing screw 9-1, and the highest position of the top is limited to the inside of the first limiting boss.

[0045] The arrangement method and connection structure of the two loading mechanisms in the embodiment of the present invention are as follows: on the one hand, the swing loading mechanism is arranged along the swing force loading direction, and is used to clamp the elastic bearing dummy A and press the elastic bearing dummy A against the outer end surface of the main propeller central part arm dummy B; on the other hand, the double fork ears on both sides of the centrifugal force loading mechanism pass through two rectangular through holes, and press the elastic bearing dummy A against the outer end surface of the main propeller central part arm dummy B, and the centrifugal force loading mechanism is arranged along the centrifugal force loading direction.

[0046] In one implementation of the embodiment of the present invention, Figure 2 and Figure 3 As shown, the oscillation loading mechanism may include: a joint baffle 4, a oscillation clamping joint 5, a clamping screw 5-1, a baffle fixing screw 6, and a second fixing screw 9-2.

[0047] In this implementation, the joint baffle 4 is fixedly installed on the bottom of the fixing plate by the second fixing screw 9-2, and the second fixing screw 9-2 fixes the bottom of the main propeller central part arm dummy B to one side end of the fixing plate.

[0048] In this implementation, the swing clamping joint 5 is configured as a U-shaped groove structure, with its bottom end face placed on the upper end face of the joint baffle 4, and the two side ends of the U-shaped groove structure are symmetrically arranged along the swing force loading direction, and threaded holes are symmetrically arranged at the lower ends of both sides of the U-shaped groove structure. The elastic bearing dummy A nested in the inner side of the U-shaped groove is clamped and positioned by the clamping screw 5-1, and one side of the elastic bearing dummy A is pressed against the outer side of the main propeller central component support arm dummy B.

[0049] Furthermore, the shimmy loading mechanism in this implementation may also include: a shimmy loading handle 10 and a shimmy loading bolt 11 .

[0050] In this implementation, symmetrical through holes are provided at both side ends of the U-shaped groove structure, which can be connected to one end of the swing loading handle 10 through a swing loading bolt 11 passing through the through hole. The other end of the swing loading handle 10 is connected to the swing loading actuator, and the swing force is applied to the elastic bearing dummy A through the swing loading handle 10.

[0051] In addition, a positioning boss is provided at the bottom of the inner side of the U-shaped groove of the U-shaped groove structure, which can be embedded in the inner groove of the elastic bearing dummy A.

[0052] In one implementation of the embodiment of the present invention, Figures 1 to 3 As shown, the centrifugal force loading mechanism may include: a right-angle baffle 7, a centrifugal force clamping joint 8, a second fixing screw 9-2, a swing loading bolt 11, a centrifugal force loading joint 12, and a centrifugal force loading bolt 13.

[0053] In this implementation, the centrifugal force clamping joint 8 is configured as a U-shaped double-fork ear structure, which can pass through two rectangular through holes on the fixed plate and is symmetrically arranged along the centrifugal force loading direction.

[0054] In this implementation, the inner end face of the U-shaped portion of the U-shaped double-fork ear structure abuts against the end face on the opposite side of the elastic bearing dummy A, and a second limiting boss is provided on the top of the inner end face of the U-shaped portion to limit the highest position of the top of the elastic bearing dummy A. A threaded hole is provided on the bottom end face of the U-shaped portion, and one side plate of the right-angle baffle 7 is fixedly connected to the bottom end of the U-shaped portion by screws or bolts, and the elastic bearing dummy A is positioned and fixed along the swing force direction by the second limiting boss and the other side plate of the right-angle baffle 7;

[0055] In this implementation, symmetrical through holes are provided at both side ends of the U-shaped double-fork ear structure for connecting the centrifugal force loading joint 12 via the centrifugal force loading bolts 13 penetrating through the through holes.

[0056] Furthermore, the centrifugal force loading mechanism in this implementation may also include: a centrifugal force loading steel cable 14 and a loading pin 15 .

[0057] In this implementation, the centrifugal force loading joint 12 is configured with a single ear piece with a through hole at one end, which is connected to the U-shaped double-fork ear end of the centrifugal force clamping joint 8 through a centrifugal force loading bolt 13, and the other end is configured as a double ear piece with a through hole, which is connected to one end of the centrifugal force loading cable 14 through a loading pin 15 passing through the through hole. The other end of the centrifugal force loading cable 14 applies centrifugal force to the elastic bearing dummy A by connecting the centrifugal force loading actuator.

[0058] In a specific implementation, the axis of the centrifugal force loading cable 14 coincides with the centrifugal force loading direction, so that the applied centrifugal force is accurately transmitted along the centrifugal force loading cable 14 to the contact surface between the elastic bearing dummy A and the main propeller central part arm dummy B, thereby generating friction on the contact surface.

[0059] Based on the friction coefficient test device under large load centrifugal force provided by the above embodiments of the present invention, the embodiment of the present invention also provides a corresponding friction coefficient test method under large load centrifugal force, which is specifically a method performed by the friction coefficient test device under large load centrifugal force provided by any of the above items, and is specifically used to measure the friction coefficient of the contact surface between the elastic bearing dummy A and the main propeller central part arm dummy B. The friction coefficient test method provided by the embodiment of the present invention may include the following steps:

[0060] Step 1, continuously applying a centrifugal force of a specified load to the elastic bearing dummy A through a centrifugal force loading mechanism;

[0061] Step 2, in the process of continuously applying the centrifugal force, a slowly increasing oscillating force is applied to the elastic bearing dummy A through the oscillating loading mechanism, so that a friction force is generated between the contact surface of the elastic bearing dummy A and the main propeller central component support arm dummy B; wherein the oscillating force loading direction is perpendicular to the centrifugal force loading direction;

[0062] Step 3: When the applied oscillating force increases to a critical mutation value, stop loading and record the maximum oscillating force value.

[0063] Furthermore, the friction coefficient testing method provided in the embodiment of the present invention may also include the following steps:

[0064] Step 4: Calculate the friction coefficient according to the maximum swing force value and the centrifugal force value of the fixed load: centrifugal force value / maximum swing force value.

[0065] Furthermore, the friction coefficient testing method provided in the embodiment of the present invention may also include the following steps:

[0066] Step 5, by changing the materials of the elastic bearing dummy A and the main propeller central arm dummy B, and the roughness of the mounting surface, the friction coefficient of different combination test pieces is tested.

[0067] The friction coefficient test device and method under large load centrifugal force provided by the embodiment of the present invention can not only realize the real simulation of the assembly boundary conditions and loading conditions during the fatigue test of the main propeller center piece, but also can truly simulate the materials, installation surface roughness, and conditions of bearing large centrifugal force and swing force of the main propeller center piece support arm and the elastic bearing dummy; it can also realize the friction coefficient test of the installation surface of the main propeller center piece support arm and the elastic bearing dummy. In addition, the friction coefficient test device provided by the embodiment of the present invention has a coordinated structure, stable loading, and high reliability of test data.

[0068] The specific implementation of the friction coefficient testing device and method under high load centrifugal force provided by the embodiment of the present invention is described in detail below through a specific embodiment.

[0069] Combination Figures 1 to 3 As shown, the specific structure of the friction coefficient test device under large load centrifugal force provided by the specific embodiment, the friction coefficient test device under large load centrifugal force provided by the specific embodiment, is used for the friction coefficient test of the fatigue test of the main propeller central part. The structure of the friction coefficient test device may include: a test bench bottom plate 1, a fixed support 2, a fixing screw 3, a joint baffle 4, a swing clamping joint 5, a clamping screw 5-1, a baffle fixing screw 6, a right-angle baffle 7, a centrifugal force clamping joint 8, a first fixing screw 9-1, a second fixing screw 9-2, a swing loading handle 10, a swing loading bolt 11, a centrifugal force loading joint 12, a centrifugal force loading bolt 13, a centrifugal force loading steel cable 14, a loading pin 15 and an elastic bearing dummy A, a main propeller central part arm dummy B; wherein, testing the friction coefficient between the elastic bearing dummy A and the mounting surface of the central part arm B is the test function required to be realized by the device.

[0070] In this specific embodiment, the mounting surfaces of the tested elastic bearing dummy A and the main propeller center piece arm dummy B are arranged along the Y direction of the whole machine coordinate system and perpendicular to the X direction of the whole machine coordinate system. The main propeller center piece arm dummy B is installed on the fixed support 2 by means of the first fixing screw 9-1 and the second fixing screw 9-2. The elastic bearing dummy A is pressed against the mounting surface of the main propeller center piece arm dummy B by means of the joint baffle 4, the swing clamping joint 5 and the clamping screw 5-1, and a large load pressure is applied to the elastic bearing dummy A by means of the centrifugal force clamping joint 8.

[0071] In this specific embodiment, the joint baffle fixing screw, that is, the second fixing screw 9-2, is slightly longer than the test piece fixing screw, that is, the first fixing screw 19-1.

[0072] The first fixing screw 9 - 1 only connects the main propeller central part arm dummy B to the fixed support 2 , and the second fixing screw 9 - 2 connects the joint baffle 4 and the main propeller central part arm dummy B to the fixed support 2 .

[0073] The swing clamping joint 5 in this specific embodiment is a U-shaped groove structure, which is symmetrically arranged relative to the Y direction of the whole machine coordinate system (symmetrically placed on the upper end face of 4 along the swing force loading direction): the swing clamping joint 5 is placed on the joint baffle 4 with its bottom end face, and a boss is arranged on the inner side to be embedded in the inner groove of the elastic bearing dummy A; symmetrical threaded holes are arranged at the lower ends of both sides of the U-shaped groove, and the elastic bearing dummy A is tightened and positioned by screwing in the clamping screws 5-1; symmetrical through holes are arranged at the upper ends of both sides of the U-shape, and the swing loading bolts 11 are screwed in through the through holes to connect the swing loading handle 10, and the swing loading handle 10 is connected to the swing loading actuator, and the swing force is applied to the elastic bearing dummy A by connecting the swing loading handle 10.

[0074] The centrifugal force clamping joint 8 in this specific embodiment is a U-shaped double-fork ear structure, which is symmetrically arranged relative to the X-direction of the coordinate system of the entire machine. The inner end face of the U-shaped bottom presses the elastic bearing dummy A, and a boss is arranged at the upper end of the inner end face of the U-shaped bottom along the Y-direction to limit the highest position of the top of A. A threaded hole is arranged at the lower end along the Y-direction, and a right-angle baffle 7 is screwed in through the threaded hole. The boss and the right-angle baffle 7 position and fix the elastic bearing dummy A along the Y-direction; symmetrical through holes are arranged on both side ends of the U-shape, and centrifugal force loading bolts 13 are screwed in through the through holes to connect the centrifugal force loading joint 12.

[0075] One end of the centrifugal force loading joint 12 in this specific embodiment is a single-ear piece, which is provided with a through hole and connected to the centrifugal force clamping joint 8, and the other end is a double-ear piece, which is provided with a through hole and is connected to the centrifugal force loading cable 14 through a loading pin 15. The axis of the loading cable 14 coincides coaxially with the X-direction of the whole machine coordinate system, and a large load pressure is applied to the elastic bearing dummy A by connecting the loading actuator.

[0076] Although the embodiments disclosed in the present invention are as above, the contents are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined by the attached claims.

Claims

1. A friction coefficient testing device under high load centrifugal force, characterized in that: include: A test bench bottom plate (1), a fixed support (2), a fixing screw (3), a first fixing screw (9-1), and a shimmy loading mechanism and a centrifugal force loading mechanism; The fixed support (2) is configured as an inverted T-shaped structure, comprising: a connecting base plate and a fixing plate which are arranged perpendicular to each other; the connecting base plate is fixedly mounted on the test bench base plate (1) by fixing screws (3); two rectangular through holes are symmetrically arranged in the middle of the fixing plate, and a first limiting boss is arranged on the top of one side of the fixing plate; The top of the main propeller central part arm dummy (B) is fixedly mounted on the top of one side of the fixing plate by a first fixing screw (9-1), and the highest position of the top is limited to the inner side of the first limiting boss; the swing loading mechanism is arranged along the swing force loading direction, and is used to clamp the elastic bearing dummy (A), and press the elastic bearing dummy (A) against the outer end surface of the main propeller central part arm dummy (B); the double fork ears on both sides of the centrifugal force loading mechanism pass through the two rectangular through holes, and press the elastic bearing dummy (A) against the outer end surface of the main propeller central part arm dummy (B), and the centrifugal force loading mechanism is arranged along the centrifugal force loading direction; The swing loading mechanism comprises: a joint baffle (4), a swing clamping joint (5), a clamping screw (5-1), a baffle fixing screw (6), and a second fixing screw (9-2); The joint baffle (4) is fixedly mounted on the bottom of the fixing plate by means of a second fixing screw (9-2), and the second fixing screw (9-2) fixes the bottom of the main propeller central part support arm dummy (B) to one side end of the fixing plate; The swing clamping joint (5) is configured as a U-shaped groove structure, with its bottom end face placed on the upper end face of the joint baffle (4), and the two side ends of the U-shaped groove structure are symmetrically arranged along the swing force loading direction, and the two lower ends of the U-shaped groove structure are symmetrically arranged with threaded holes, and the elastic bearing dummy (A) embedded in the inner side of the U-shaped groove is clamped and positioned by a clamping screw (5-1), and one side of the elastic bearing dummy (A) is pressed against the outer side surface of the main propeller central component support arm dummy (B).

2. The friction coefficient testing device under high load centrifugal force according to claim 1, characterized in that: The shimmy loading mechanism further comprises: a shimmy loading handle (10) and a shimmy loading bolt (11); Symmetrical through holes are provided at both side ends of the U-shaped groove structure for connecting to one end of the swing loading handle (10) via a swing loading bolt (11) passing through the through hole; the other end of the swing loading handle (10) is connected to a swing loading actuator, and a swing force is applied to the elastic bearing dummy (A) via the swing loading handle (10).

3. The friction coefficient testing device under high load centrifugal force according to claim 1, characterized in that: The bottom of the inner side of the U-shaped groove of the U-shaped groove structure is provided with a positioning boss for embedding into the inner groove of the elastic bearing dummy (A).

4. The friction coefficient testing device under high load centrifugal force according to claim 2, characterized in that: The centrifugal force loading mechanism comprises: a right-angle baffle (7), a centrifugal force clamping joint (8), a second fixing screw (9-2), a shimmy loading bolt (11), a centrifugal force loading joint (12), and a centrifugal force loading bolt (13); Wherein, the centrifugal force clamping joint (8) is configured as a U-shaped double-fork ear structure, which is used to pass through the two rectangular through holes on the fixing plate and is symmetrically arranged along the centrifugal force loading direction; The inner end face of the U-shaped portion of the U-shaped double-fork ear structure abuts against the end face of the elastic bearing dummy (A) on the opposite side, and a second limiting boss is provided on the top of the inner end face of the U-shaped portion for limiting the highest position of the top end of the elastic bearing dummy (A). A threaded hole is provided on the bottom end face of the U-shaped portion, and one side plate of the right-angle baffle (7) is fixedly connected to the bottom end of the U-shaped portion by screws or bolts, and the elastic bearing dummy (A) is positioned and fixed along the swing force direction by the second limiting boss and the other side plate of the right-angle baffle (7); Symmetrical through holes are provided at both side ends of the U-shaped double-fork ear structure, and are used to connect the centrifugal force loading joint (12) via centrifugal force loading bolts (13) passing through the through holes.

5. The friction coefficient testing device under high load centrifugal force according to claim 4, characterized in that: The centrifugal force loading mechanism further comprises: a centrifugal force loading steel cable (14) and a loading pin (15); The centrifugal force loading joint (12) is provided with a single ear piece with a through hole at one end, connected to the U-shaped double-fork ear end of the centrifugal force clamping joint (8) via a centrifugal force loading bolt (13), and the other end is provided with a double ear piece with a through hole, connected to one end of a centrifugal force loading steel cable (14) via a loading pin (15) passing through the through hole, and the other end of the centrifugal force loading steel cable (14) applies centrifugal force to the elastic bearing dummy (A) by connecting the centrifugal force loading actuator; The axis of the centrifugal force loading steel cable (14) coincides with the centrifugal force loading direction, so that the applied centrifugal force is accurately transmitted along the centrifugal force loading steel cable (14) to the contact surface between the elastic bearing dummy (A) and the main propeller center piece support arm dummy (B), thereby generating friction on the contact surface.

6. A method for testing the coefficient of friction under high load centrifugal force, characterized in that: The friction coefficient of the contact surface between the elastic bearing dummy (A) and the main propeller central part support arm dummy (B) is measured using a friction coefficient test device under a large load centrifugal force as described in any one of claims 1 to 5; The friction coefficient test method includes: Step 1, continuously applying a centrifugal force of a specified load to the elastic bearing dummy (A) through a centrifugal force loading mechanism; Step 2, in the process of continuously applying the centrifugal force, applying a slowly increasing oscillating force to the elastic bearing dummy (A) through the oscillating loading mechanism, so that a friction force is generated between the contact surfaces of the elastic bearing dummy (A) and the main propeller central component support arm dummy (B); wherein the oscillating force loading direction is perpendicular to the centrifugal force loading direction; Step 3: When the applied oscillating force increases to a critical mutation value, stop loading and record the maximum oscillating force value.

7. The friction coefficient testing method under high load centrifugal force according to claim 6, characterized in that: Also includes: Step 4: Calculate the friction coefficient according to the maximum swing force value and the centrifugal force value of the fixed load: centrifugal force value / maximum swing force value.

8. The friction coefficient testing method under high load centrifugal force according to claim 7, characterized in that: Also includes: Step 5, by changing the materials of the elastic bearing dummy (A) and the main propeller center arm dummy (B), and the mounting surface roughness, the friction coefficient of different combination test pieces is tested.

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