A variable pitch pull rod relay control mechanism inside the shaft of a rotor test bench

Abstract

The present invention belongs to the technical field of helicopter rotor test, and particularly relates to a relay control mechanism for variable pitch pull rods inside the shaft of a rotor test bench. The control mechanism is characterized in that it comprises an upper variable pitch drive unit, a variable pitch pull rod assembly inside the shaft, and a lower variable pitch drive unit; the lower variable pitch drive unit and the upper variable pitch drive unit are symmetrically distributed along the center of the variable pitch pull rod assembly inside the shaft. The lower drive unit serves as a power source and transmits power to the upper variable pitch drive unit through the variable pitch pull rod assembly inside the shaft to drive the change of the torsion angle of the rotor hub, thereby realizing the change of the collective pitch and cyclic pitch of the upper rotor system.

Description

Technical Field

[0001] The present invention belongs to the technical field of helicopter rotor tests, and specifically relates to the pitch control of rotor blades on a rotor test bench. Background Art

[0002] The rotor test bench needs to conduct full-scale functional tests and aerodynamic performance tests on a new rotor system. When conducting the above tests, it is necessary to achieve the change and control of the blade angle. Considering the influence of the hub space and the control system on the rotor force measurement in the test bench design, the upper rotor control system adopts a lower-mounted type, and the transmission path is relatively long. The inner ring of the upper rotor swashplate is a moving ring, and the outer ring is a fixed ring. To achieve the change of the blade angle of the upper rotor, an actuator is required for driving. The power of the actuator needs to pass through the lower rotor reduction gearbox, the lower rotor balance, the upper rotor balance and other force measurement and transmission systems. To simulate the length of the test piece and at the same time meet the requirements of rotor load measurement and pitch change, the torsion of the upper rotor hub realizes the change of the collective pitch and cyclic pitch of the rotor system. The length of the upper rotor control pull rod is much longer than the length of the test piece. If only the test piece is used as the pitch pull rod of the upper rotor, the change and control of the blade angle of the upper rotor cannot be achieved; directly using the original pitch pull rod cannot achieve the change of the collective pitch and cyclic pitch of the upper rotor system within the limited space and size. Summary of the Invention

[0003] The purpose of the present invention: to propose an in-axis pitch pull rod relay control mechanism for a rotor test bench to solve the problem of realizing the change of the collective pitch and cyclic pitch of the upper rotor system within a limited space.

[0004] The technical solution of the present invention: an in-axis pitch pull rod relay control mechanism for a rotor test bench, the control mechanism includes an upper pitch drive unit, an in-axis pitch pull rod assembly, and a lower pitch drive unit; the lower pitch drive unit and the upper pitch drive unit are quasi-symmetrically distributed along the center of the in-axis pitch pull rod assembly. The lower drive unit is used as the power source and is transmitted to the upper pitch drive unit through the in-axis pitch pull rod assembly to drive the change of the torsion angle of the rotor hub, so as to realize the change of the collective pitch and cyclic pitch of the upper rotor system.

[0005] Further, the upper pitch drive unit includes an upper rocker arm, an upper blade pull rod, and an upper rotor hub. The upper rocker arm, the upper blade pull rod, and the upper rotor hub form a lever mechanism; one end of the upper rocker arm is connected to one end of the upper blade pull rod, and the other end is connected to the in-axis pitch pull rod assembly; the other end of the upper blade pull rod is connected to the upper rotor hub; the upper rocker arm can rotate around its own center point.

[0006] Further, spherical plain bearings are arranged at both connection positions of the upper rocker arm.

[0007] Further, the center of the upper rocker arm is fixed on the central part of the upper rotor hub through a support rod.

[0008] Furthermore, the lower variable pitch drive unit includes a lower rocker arm, a lower driving rod, and an actuator cylinder, and the lower rocker arm, the lower driving rod, and the actuator cylinder constitute a group of lever mechanisms; one end of the lower rocker arm is connected to one end of the lower driving rod, and the other end is connected to the variable pitch rod assembly in the shaft; the other end of the lower driving rod is connected to the actuator cylinder; the lower rocker arm can rotate around its own center point.

[0009] Furthermore, the in-axis variable pitch rod assembly includes a first upper rotor rod, a first hollow tube, a relay slider device, a second hollow tube, and a second upper rotor rod; wherein, the first hollow tube is docked with the second hollow tube, and the relay slider device is placed at the docking position of the two hollow tubes, one end of the first upper rotor rod is docked with one end of the second upper rotor rod, and the docking position is placed in the arc groove of the relay slider device, and slides in the arc groove to realize power transmission.

[0010] Furthermore, the relay slider device includes a relay slider, a pin shaft, and a pull rod fork ear; the pull rod fork ear is connected to the second upper rotor pull rod, and is connected to the joint bearing at the end of the first upper rotor pull rod through the pin shaft; the pin shaft slides in the arc groove of the relay slider, and the motion trajectory is consistent with the upper and lower pitch drive units.

[0011] Furthermore, the lever mechanism in the upper pitch-variable drive unit and the lever mechanism in the lower pitch-variable drive unit both include multiple groups, the number of which is consistent with the number of upper rotor blades and is in a one-to-one correspondence.

[0012] The beneficial effects of the present invention are as follows: the torque-changing pull rod relay control mechanism in the rotor test bench shaft proposed by the present invention realizes the use of the test piece pull rod in the test state, and also extends the distance between the lower upper rotor tilter and the upper rotor hub; it can realize the change of the collective pitch and cyclic pitch of the upper rotor system in a limited space and size. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the structure of the torque converter rod relay control mechanism within the shaft;

[0014] Figure 2 It is a schematic diagram of the structure of the relay slider device;

[0015] Figure 3 This is a schematic diagram of the power source structure of the relay control mechanism;

[0016] Among them, there are lower rocker arm 1, upper rotor rod-lower section 2, upper control-lower section hollow tube 3, relay slider device 4, upper control-upper section hollow tube 5, upper rotor rod-upper section 6, upper rocker arm 7, upper blade rod 8, upper rotor hub 9, lower drive rod 10, automatic tilt mechanism dynamic ring 11, automatic tilt mechanism fixed ring 12, actuator 13, relay slider 4.1, pin 4.2, and rod fork ear 4.3. Detailed implementation manners

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to 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. In the description of the present invention, it should be noted that terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, terms such as "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0018] See the attached Figure 1 , Figure 3 As shown, taking the design of the upper rotor control system of a certain type of helicopter rotor test as an example, a relay control mechanism for variable pitch pull rods inside the shaft of a rotor test bench is specifically designed. Figure 1The structure of the power source part is not shown in detail; in terms of the designed quantity, the in-axle pitch-changing pull rods correspond one-to-one with the number of blades of the rotor system; the designed control mechanism includes a lower rocker arm 1, an upper rotor pull rod - lower section 2, an upper control - lower section hollow tube 3, a relay slider device 4, an upper control - upper section hollow tube 5, an upper rotor pull rod - upper section 6, an upper rocker arm 7, an upper blade pull rod 8, an upper rotor hub 9, a lower drive pull rod 10, a swashplate moving ring 11, a swashplate stationary ring 12, and an actuator 13; among them, the lower rocker arm 1, the lower drive pull rod 10, the swashplate moving ring 11, the swashplate stationary ring 12, and the actuator 13 form the power source part and serve as the lower pitch-changing drive unit; the actuator 13 provides power to drive the swashplate stationary ring 12 to move vertically up and down along the axis, and drives the connected swashplate moving ring 11 to move up and down accordingly, and further drives the lower drive pull rod 10 to drive one end of the lower rocker arm 1 to move up and down, forcing the lower rocker arm 1 to rotate around its own center point, and the other end of the lower rocker arm 1 moves accordingly to drive the upper rotor pull rod - lower section 2 to move along the inner arc groove of the relay slider device 4; the upper rotor pull rod - upper section 6, the upper rocker arm 7, the upper blade pull rod 8, and the upper rotor hub 9 together form the blade drive part and serve as the upper pitch-changing drive unit; one end of the upper rotor pull rod - upper section 6 is connected to the upper rotor pull rod - lower section 2, and the connection point is set in the arc groove of the relay slider device 4. The upper rotor pull rod - upper section 6 and the upper rotor pull rod - lower section 2 move in tandem. The upper rotor pull rod - upper section 6 drives one end of the upper rocker arm 7 to move, the upper rocker arm 7 rotates around its own center point, the other end of the upper rocker arm 7 drives the upper blade pull rod 8 to move, and finally drives the upper rotor hub 9 to move; the upper pitch-changing drive unit and the lower pitch-changing drive unit move in tandem, and the total pitch and cyclic pitch changes of the upper rotor system are realized through the above transmission process.

[0019] See the appendix Figure 2 The relay slider device 4 consists of a relay slider 4.1, a pin shaft 4.2, and a pull rod fork ear 4.3, as Figure 2 shown. Four relay sliders 4.1 are combined into a whole cylinder, which has an interference fit with the inner hole of the upper control - upper section hollow tube 5 and is radially connected by bolts. The pull rod fork ear 4.3 is connected to the upper rotor pull rod - lower section 2 by threads and is connected to the lower end spherical bearing of the upper rotor pull rod - upper section 6 through the pin shaft 4.2. The pin shaft 4.2 slides in the arc groove of the relay slider 4.1.

[0020] The upper control - lower section hollow tube 3 is connected to the inner ring of the upper rotor swashplate, and the upper control - upper section hollow tube 5 is connected to the upper rotor rotating balance. The pitch-changing control transmission route of the upper rotor blade is: upper rotor actuator → upper rotor swashplate → lower rocker arm 1 → upper rotor pull rod - lower section 2 → relay slider device 4 → upper rotor pull rod - upper section 6 → upper rocker arm 7 → upper blade pull rod 8 → upper rotor blade.

[0021] Working principle: The upper rotor has a total of four blades, corresponding to four tie rods. The upper and lower sections of each tie rod form a parallelogram mechanism with the hinge points of the upper rocker arm and the lower rocker arm. The relay slider device connects the upper and lower sections of the tie rod, and the connection point slides in the arc groove, serving to extend the tie rod.

[0022] The key design points of the present invention are reflected in the following aspects:

[0023] Utilize the arc groove of the relay slider to extend the effective length of the upper rotor tie rod;

[0024] Utilize the parallelogram mechanism to achieve variable pitch control of the upper rotor blades;

[0025] The hollow tube is connected to the relay slider, the inner ring of the upper swashplate, and the rotating balance of the upper rotor, realizing the synchronous rotation of the tie rod, the hub, and the swashplate.

[0026] The present invention realizes a relay control mechanism for variable pitch tie rods inside the shaft of a rotor test bench. By means of the relay control mechanism, the length of the variable pitch tie rod of the upper rotor is extended, avoiding the phenomenon of tie rod instability caused by excessive length of the upper rotor tie rod. A relay slider is designed in the middle section of the tie rod, and technical indicators such as the length of the simulated test piece are set above the relay slider. Below the relay slider, a shorter control tie rod than the test piece and a lower-mounted upper rotor swashplate in the manner of the test piece are adopted, which not only meets the requirements of simulating the operating conditions of the test piece but also extends the distance between the lower-mounted upper rotor swashplate and the rotor, meeting the needs of rotor load measurement.

[0027] As described above, the above are only specific embodiments of the present invention. The present invention has been described in detail, and the unelaborated parts are conventional technologies. However, the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. The protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A variable pitch pull rod relay control mechanism inside the shaft of a rotor test bench, characterized in that, The control mechanism consists of an upper pitch-variable drive unit, an in-axis pitch-variable pull rod assembly, and a lower pitch-variable drive unit; the lower pitch-variable drive unit and the upper pitch-variable drive unit are quasi-symmetrically distributed along the center of the in-axis pitch-variable pull rod assembly. The lower pitch-variable drive unit serves as a power source, which is transmitted to the upper pitch-variable drive unit through the in-axis pitch-variable pull rod assembly to drive the rotor hub torsion angle to change, thereby achieving changes in the collective pitch and cyclic pitch of the upper rotor system; The in-axis variable pitch rod assembly includes a first upper rotor rod, a first hollow tube, a relay slider device, a second hollow tube, and a second upper rotor rod; wherein the first hollow tube is docked with the second hollow tube, and the relay slider device is placed at the docking position of the two hollow tubes, one end of the first upper rotor rod is docked with one end of the second upper rotor rod, and the docking position is placed in the arc groove of the relay slider device, and slides in the arc groove to realize power transmission.

2. The relay control mechanism for variable pitch pull rod inside the shaft of a rotor test stand according to claim 1, characterized in that, The upper pitch drive unit includes an upper rocker arm, an upper blade pull rod, and an upper rotor hub. The upper rocker arm, upper blade pull rod, and upper rotor hub constitute a group of lever mechanisms; one end of the upper rocker arm is connected to one end of the upper blade pull rod, and the other end is connected to the pitch rod assembly in the shaft; the other end of the upper blade pull rod is connected to the upper rotor hub; the upper rocker arm can rotate around its own center point.

3. The relay control mechanism for variable pitch pull rod inside the shaft of a rotor test stand according to claim 2, characterized in that, Joint bearings are arranged at the connection positions at both ends of the upper rocker arm.

4. The relay control mechanism for variable pitch pull rod inside the shaft of a rotor test stand according to claim 3, characterized in that, The center of the upper rocker arm is fixed to the center piece of the upper rotor hub through a support rod.

5. The relay control mechanism for variable pitch pull rod inside the shaft of a rotor test bench according to claim 1, characterized in that, The lower variable pitch drive unit includes a lower rocker arm, a lower driving rod, and an actuator cylinder, which constitute a group of lever mechanisms; one end of the lower rocker arm is connected to one end of the lower driving rod, and the other end is connected to the variable pitch rod assembly in the shaft; the other end of the lower driving rod is connected to the actuator cylinder; the lower rocker arm can rotate around its own center point.

6. The relay control mechanism for variable pitch tie rods inside the shaft of a rotor test bench according to claim 1, characterized in that, The relay slider device includes a relay slider, a pin shaft, and a pull rod fork ear; the pull rod fork ear is connected to the second upper rotor pull rod, and is connected to the joint bearing at the end of the first upper rotor pull rod through the pin shaft; the pin shaft slides in the arc groove of the relay slider, and the motion trajectory is consistent with the upper and lower pitch drive units.

7. A variable pitch pull rod relay control mechanism inside the shaft of a rotor test stand according to claim 1, characterized in that, The lever mechanism in the upper pitch-changing drive unit and the lever mechanism in the lower pitch-changing drive unit both include multiple groups, the number of which is consistent with the number of upper rotor blades and is in a one-to-one correspondence.

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