RU77430U1 - AUTOMATED UNIVERSAL STAND FOR TESTS OF PETAL GAS-DYNAMIC SUPPORTS - Google Patents

Abstract

The utility model relates to test equipment used to conduct studies of the characteristics of petal gas-dynamic supports.

The objective of the utility model is to create an automated universal bench for testing petal gas-dynamic supports, which will be used in the quality control line for manufacturing petal gas-dynamic supports.

This task is achieved by the fact that in an automated universal bench for testing petal gas-dynamic supports, containing a test setup, including a housing, with a rotor placed in the petal gas-dynamic supports, a pneumatic drive turbine is installed on one of its ends, and the second end of the rotor is made in the form of a smooth cylinder load device, in the chamber of which a pressure sensor and a capacitive linear displacement sensor are installed, while a tachometer is installed from the side of the pneumatic drive turbine in this case, the rotor is made with a centrally located fifth, the pneumatic actuator is combined with the braking device, and the petal gas-dynamic supports are attached to the housing by bushings, while the pressure sensor, capacitive linear displacement sensor and tachometer are electrically connected to the analog inputs of the information input-output board, and the outputs are electrically connected to the control inputs of the shut-off valve, pressure regulator of the braking device, pressure regulator of the pneumatic actuator and pressure regulator of the load device,

moreover, the input-output information board is electrically connected to a personal computer.

Description

The utility model relates to test equipment used to conduct studies of the characteristics of petal gas-dynamic supports (hereinafter referred to as LGO).

The prior art test bench for LGO (Zakharova N.E., Bragin AN "Experimental studies of the elastic compliance of the petal gas-dynamic thrust bearings", Moscow: Engineering Science No. 3, 1984, p.99-105), selected in as a prototype. This stand contains a test setup, including a housing with a rotor located in the gas-lined gas-dynamic supports, on one of the ends of which a pneumatic drive turbine is installed, and the second end of the rotor is made in the form of a smooth cylinder of a loading device, the pressure in the chamber of which is measured by a manometer, the rotor movement is measured by capacitive linear displacement sensor, and on the turbine side there is an induction sensor of the rotor speed measuring system.

The disadvantages of this stand should include:

- mismatch of the mass distribution of the installation rotor to the rotor of the turbomachine and, as a consequence, the discrepancy between the loading conditions of the LGO in the installation and the loading conditions in the real turbomachine;

- the lack of braking devices and the associated problems of controlling the angular speed of the rotor of the stand;

- collection of information during testing is not automated;

- manual control of the loading device;

- processing of measurement results is not automated.

The objective of the utility model is to create an automated universal bench for testing petal gas-dynamic supports, which will be used in the quality control line for manufacturing petal gas-dynamic supports.

This task is achieved by the fact that in an automated universal bench for testing petal gas-dynamic supports, containing a test setup, including a housing, with a rotor located in the petal gas-dynamic supports, a pneumatic drive turbine is installed on one of its ends, and the second end of the rotor is made in the form of a smooth cylinder load device, in the chamber of which a pressure sensor and a capacitive linear displacement sensor are installed, while a tachometer is installed from the side of the pneumatic drive turbine , according to the utility model, the rotor is made with a centrally located fifth, the pneumatic actuator is combined with the braking device, and the petal gas-dynamic supports are attached to the housing by bushings, while the pressure sensor, capacitive linear displacement sensor and tachometer are electrically connected to the analog inputs of the information input-output board, and its outputs are electrically connected to the control inputs of the shut-off valve, pressure regulator of the braking device, pressure regulator of the pneumatic actuator and pressure regulator of the load device properties, and the input / output information board is electrically connected to a personal computer.

The execution of the rotor in a bench with a centrally located heel is necessary in order to vary the mass and moment of inertia of the rotor of the bench due to a change in the thickness and outer diameter of the heel, since in the case of mass-dimensional simulation of the rotor, the conditions of loading and operation of the LGO in the bench are as close as possible to the conditions of loading and operation of the LGO in the turbomachine for which they are intended.

The braking device in the stand provides the ability to better control the angular speed of the rotor, as well as the ability to implement software braking of the rotor. Since the placement of the brake wheel in the rotor of the stand is difficult, the role of the brake wheel is played by a pneumatic drive turbine.

The bushings through which the LGO are attached to the bench body are necessary to ensure the versatility of the bench for a number of standard sizes of LGO turbomachines of small and medium power.

The use of a pressure sensor, a capacitive linear displacement sensor and a tachometer with an electrical signal output provides an increase in the speed of data collection when using petal supports in the quality control line.

The use of an information I / O board is necessary to collect information from a pressure sensor, a capacitive linear displacement sensor and a tachometer, as well as to implement control of a pneumatic actuator, a braking device, a loading device, and a shut-off valve.

A personal computer is necessary for collecting and processing information from the information input-output board, as well as for software control of devices connected to the analog outputs of the information input-output board.

The design of an automated universal bench for testing petal gas-dynamic supports is shown in the drawing, where the elements of the stand are shown schematically.

A smooth cylindrical shaft 1, one end of which is made with a flat end perpendicular to the axis of rotation, and a pneumatic drive turbine 2, a nut 3, and two symmetrically located pins 4 are fixed on the other end, by means of which the turbine 2 is fixed relative to the shaft 1 and together with the centrally located fifth 5 (hereinafter referred to as heel 5) form the rotor of the installation. Heel 5 is mounted with an interference fit on shaft 1

and allows you to bring the mass and moment of inertia of the rotor of the installation to the rotor of the turbomachine.

The rotor is fixed in two lobe gas-dynamic bearings 6 and thrust bearings 7, which are attached to the installation housing consisting of a stationary base 8 and flange 9 by means of adapter sleeves 10 and 11. The cylinder of the loading device 13 (hereinafter referred to as cylinder 13) is bolted to the flange 9 the surface of which has a non-contact labyrinth seal 14, and at the end there is a capacitive linear displacement sensor 15 and a pressure sensor 16. The fastening of the capacitive linear displacement sensor 15 allows it to be axially displaced by board relative to the cylinder 13 and fix the position. At the base of the cylinder 13, openings are provided for venting air.

The preload in the petal gas-dynamic thrust bearings 7 is provided by the selection of the width of the adjusting ring 17.

A guide device 18 of the pneumatic drive is attached to the base 8, which also serves as the basis for the fasteners 19 of the interchangeable accelerating nozzles 20 and the brake nozzles 21. The fastening of the nozzles allows you to adjust their position (both accelerating 20 and brake 21). On the other hand, a flange 9 is attached to the base 8 with bolts 22.

At the end of the nut 3, a mark is glued, which is recorded by the optical sensor of the digital stroboscopic tachometer 23, located at a small distance from the mark. The capacitive linear displacement sensor 15, the pressure sensor 16 and the tachometer 23 are electrically connected to the analog inputs of the information input-output board 24 by their outputs, and its analog outputs are connected to the control inputs of the pressure regulator 25, which supplies air to the chamber of the load device, and pressure regulators 26 and 27, supplying two accelerating nozzles 20 and two brake nozzles 21. Through one air line, one digital output of the information input-output board 24 is connected to the shut-off valve 28.

In addition to the receiver 29, the filter 30, and the compressor 31, a safety drain valve 32 is provided.

The information input / output board 24 is controlled by a personal computer 33 (hereinafter referred to as the PC)

The stand works as follows.

In the base 8 and flange 9 of the installation casing, the test subjects LGO 6 and 7 are fixed, the turbine 2 is fixed with a nut 3, the pneumatic drive guide apparatus 18 is put on and fixed, after which the base 8 and flange 9 are fastened. The PC 33 is turned on, in the permanent memory of which the stand control program is recorded, then the compressor 31 and the power supply circuit of the controller of the capacitive linear displacement sensor 15, pressure sensor 16, tachometer 23, as well as pressure adjusters 25, 26, 27 and shut-off valve 28 (in the drawing) are turned on power circuits not shown).

The program on PC 33 controls the voltage at the analog and digital outputs of the information input / output board 24, and also reads from it the voltage values at the analog inputs.

In test mode, the program on PC 33 first tests the response of the information input / output board 24, in case of a successful test (zero error codes), opens the shut-off valve 28 with a digital output, then smoothly opens the pressure adjuster 25 of the load device by 5-10% of the upper control limit pressure. The pressure sensor 16 and the capacitive linear displacement sensor 15 should provide pressure signals in the loading chamber and the linear movement of the rotor. The values of the signals are compared with one or more of the previous values at startup and, depending on the values of the response, the program writes to the protocol file about the operability of the specified pressure transmitter and sensors. If the signals from the pressure sensor 16 and the capacitive linear displacement sensor 15 are not simultaneously changed (taking into account some control time), then a conclusion is made about the inoperability of the pressure setter 25 of the load device,

lack of power in it, damage to the control line or analog output of the I / O board 24.

Then, a control signal is supplied to the pressure adjuster 26 at a level of 5-10% of the maximum pressure control limit at its output and the response of the tachometer 23 is read. If the shaft rotation angle calculated by the signal from the tachometer 23 (the time integral of the angular velocity) does not differ more than 10% of the value of the previous run, the program writes to the log file the new angle value and the record that pressure setter 26 is working correctly. Then the signal is supplied to the pressure adjuster 26 at a level of 15-20% of the maximum pressure control limit at its output, and to the pressure control unit 27 at a level of 5-10% of the maximum pressure control limit at its output and increases to a value at which the tachometer speed will become close to zero. During this test, the signal from the tachometer is logged 23. The obtained dependence of speed on time, or in a simple version, the integral on speed is compared with previous runs, and if the mutual deviation of this value or the values of the dependence does not exceed 5-10% from the previous ones, then this will be a sufficient basis for recording information on the correct operation of the pressure setter in the log file 27. In the case of a greater difference between two or more points of the indicated dependence, either a deviation is recorded (if it fits within 15%), or rrektnoy the pressure set point 27 (at a greater mismatch than 15%).

In the case of a correct test result of pressure setters, the program will display a message and offer test options. In the event of a malfunction or failure of any of the pressure switches or sensors, the program displays a log file to the user and waits for the fault to be fixed (either by turning off the information input / output board 24, or by supplying a control signal for testing the circuits of the failed pressure switch, or interrogating the corresponding device, connected to an analog input with a period of one second with

sound signal for the possibility of checking the operability of the analog inputs of the analog-to-digital converter).

In the mode of taking the static characteristic, the shut-off valve 28 is open, and only the pressure adjuster 25 is opened from the pressure adjusters 25. In this mode, the program linearly changes the pressure in the chamber of the load device with a signal to the pressure adjuster 25, and polls at each step of the pressure change the pressure sensor 16 and the capacitive sensor linear displacement 15. Based on the cross-sectional area of the shaft 1 in the loading chamber and the pressure measured by the pressure sensor 16, the program calculates the axial loading force, and the signal from the capacitive linear displacement sensor Nij 15 corresponds to the linear displacement of the rotor. Obtained as a result of measurements, the elastic static load characteristic of the petal gas-dynamic thrust bearing 7 is recorded by the program in a file and displayed on the graph. The program remembers the signal from the capacitive linear displacement sensor 15 at zero overpressure in the chamber of the load device separately - this initial position in the dynamics will be shifted due to axial force from the turbine side.

In the program rotor acceleration mode, an increase in the rotor speed to the ascent speed is achieved by fully opening the pressure adjuster 26. Such a sharp start is necessary from the requirements of the temperature conditions of the LHE, since the LHE operate as sliding bearings until the ascent speed due to friction-sliding of the shaft on the petals the temperature of the thin lobes may exceed the limit value for a wear-resistant coating. In this case, the coating will be damaged, the friction will increase sharply and the temperature of the petals can increase so much that friction welding of the shaft with the petals occurs and the LGO and rotor assemblies will be damaged. To prevent this from happening, acceleration of the rotor to the ascent speed should occur rather quickly, which means that the starting torque of the turbine should be as high as possible.

The angular speed of the rotor is constantly monitored by a tachometer 23 and is recorded by the program from the moment of opening the pressure setter 26. Compensation of the axial force from the drive (turbine) side is constantly controlled by a capacitive linear displacement sensor 15 and pressure setter 25 - a signal is generated on it so that the excess pressure compensates the axial force from the turbine side and the rotor was in a position close to that measured in statics. This control system continues to operate until the rotor reaches the rated speed, after which the control signal to the pressure adjuster 25 is fixed at a constant level. When the rotor reaches a value of 95-99% of the required angular velocity for testing, the program will reduce the control signal to the pressure setter 26 to a value at which the angular velocity of the rotor does not increase.

If the angular speed is exceeded, the control program includes the brake nozzles 21 by the pressure regulator 27 and reduces the angular velocity of the rotor to a value close to that required for testing, after which the pressure regulator 27 closes. The signal to the pressure adjuster 26 is reduced by a fixed small amount. If the angular velocity of the rotor changes again, then the pressure adjuster 27 will work the same. Such an iterative process will continue until the rotor reaches the speed required for testing within the established tolerance. After the rotor reaches the required steady-state speed value, the bench control program will switch to the test mode of the load characteristic (bearing capacity) of the gas-dynamic throttle plate in dynamics. In this mode, in the chamber of the load device, by increasing the control signal to the pressure adjuster 25, the program generates excess pressure relative to the level that is created to compensate for the axial force from the turbine in the program rotor acceleration mode. The pressure in the chamber according to the program increases with a certain step, moving

rotor axial direction are determined by the signal from the capacitive linear displacement sensor 15. The overpressure increases by the amount measured when removing the static characteristics of the support, in order to prevent touching the heel of the surfaces of the petals.

In the programmed braking mode, the pressure switch 27 is opened, which feeds the brake nozzles 21 until the signal from the tachometer 23 becomes close to zero, after which the pressure switch 27 and the shut-off valve 28 are closed.

In the durability test mode, the control program executes the algorithm of the program mode for accelerating the rotor to the angular ascent speed, and after reaching the ascent, the algorithm for the program rotor braking mode. Then the program counts the set idle time and repeats this cycle again. In this case, the program counts the number of cycles, writes a protocol file and compares the nature of the change in angular velocity with time - in the event that the wear-resistant coating is damaged and the friction moment increases sharply, the program can determine this by a sharp decrease in the steepness of such a dependence. In this case, the program will stop the tests, and the obtained number of starts - stops and the log file will be issued as a test result.

It is advisable to use an automated universal bench for testing petal gas-dynamic supports in the serial production of turbomachines in the quality control line and in the experimental laboratory for production, as well as in independent research laboratories working in the direction of development and testing of gas-dynamic gas support.

Claims (1)

An automated universal bench for testing petal gas-dynamic supports, comprising a test installation, including a housing, with a rotor placed in the petal gas-dynamic supports, at one of the ends of which a pneumatic drive turbine is installed, and the second end of the rotor is made in the form of a smooth cylinder of a loading device, in the chamber of which is installed a pressure sensor and a capacitive linear displacement sensor, while a tachometer is installed on the side of the pneumatic drive turbine, characterized in that the rotor is made with of a centrally located fifth, the pneumatic actuator is combined with a braking device, and the petal gas-dynamic supports are attached to the housing by bushings, while the pressure sensor, capacitive linear displacement sensor and tachometer are electrically connected to the analog inputs of the information input-output board, and its outputs are electrically connected to the control inputs shut-off valve, pressure adjuster for the braking device, pressure adjuster for the pneumatic actuator and pressure adjuster for the load device, moreover, the information input-output board electrically connected to a personal computer.