Patent Description:
The present disclosure relates to the field of aero-engines, in particular to a vibration exciting system and an apparatus for testing an aero-engine rotor.

Blade vibration caused by an unsteady flow field is inevitable in a service environment of turbine rotor blades of an aero-engine. An overhigh vibration load causes a fatigue failure of the turbine blades, resulting in a serious damage to the engine. Vibration stress of the turbine rotor blades is difficult to control to an allowable range. Experimental studies and simulation predictions on vibration characteristics and vibration levels of turbine rotor blades have been conducted in both China and other countries, and an edge plate damper has been designed for the rotor blades to reduce the blade vibration stress and prevent a high-cycle fatigue failure of the blades. High-cycle fatigue refers to fatigue of a material under the action of cyclic stress lower than its yield strength after more than <NUM>,<NUM> to <NUM>,<NUM> cycles.

The blade frequency of the high-pressure turbine rotor blades is very high, and the blades are in tongue-and-groove connection with the rotor. Testing is performed in a high-speed rotating state to test the resonant frequency of the blades and the vibration reduction effect of the damper, which is closer to centrifugal load conditions during engine operation, and achieves non-linear connection of the blades. More reliable test data is obtained by frictional motion between the damper and the blades.

In the related art, a test system uses a rotor system as a research object, and uses atomized oil droplets as an excitation source to implement non-contact excitation of the rotor blades on a high-speed rotating test bed to obtain the blade vibration characteristics of the rotor system and the vibration reduction effect of the damper. <CIT> discloses a programmable jet blade excitation system. The system comprises a plurality of controllable fluid jets disposed about a blade row for exciting rotating blades with selectable frequencies of vibration. The sequential excitation of blades at a plurality of narrowly spaced frequencies and the simultaneous sensing of blade responses sufficiently resolves the resonant center frequencies and harmonics thereof in order to detect changes in characteristic blade resonances.

The inventors have found at least the following problems in the related art: in the related art, the test system is only used for rotor systems of aero-engines of specific types and specific sizes, so the test system has low universality and the test cost is high; and test systems need to be designed separately for aero-engines of different models.

The present disclosure provides a vibration exciting system and a apparatus for testing an aero-engine rotor, to improve the universality of the vibration exciting system.

Some embodiments of the present disclosure provide a vibration exciting system, including:.

In some embodiments, the guide rails are each provided with an arc-shaped slot, one of the two adjacent holders being connected to one end of the arc-shaped slot in a connecting position adjustable manner, and the other of the two adjacent holders being connected to the other end of the arc-shaped slot in a connecting position adjustable manner.

In some embodiments, the connection assembly includes:.

In some embodiments, a plurality of nozzle assemblies are mounted rotatably on each mounting seat.

In some embodiments, the mounting seat includes an oil supply cavity; and the nozzle assembly further includes:
a switching valve provided between the nozzle and the oil supply cavity of the mounting seat to control the on and off of an oil passage between the nozzle and the oil supply cavity.

In some embodiments, the vibration exciting system further includes:
an oil supply branch in fluid communication with the oil supply cavity.

In some embodiments, the switching valve is provided on the oil passage between each nozzle and the oil supply cavity.

In some embodiments, the holders are uniformly arranged circumferentially of the mounting ring.

Some embodiments of the present disclosure further provide an apparatus for testing an aero-engine rotor, including the vibration exciting system provided in any technical solution of the present disclosure.

In some embodiments, the apparatus for testing an aero-engine rotor further includes:.

In the vibration exciting system of the above technical solution, the radius size of a spraying area enclosed by the nozzle assemblies is adjusted by adjusting the positions of the holders on the fixing parts, to adapt to the test requirements of different aero-engines. The closer the holders are to the edge of the mounting ring, the greater the distance between the two adjacent holders is. The closer the mounting positions of the holders on the arc-shaped slot are to the edge of the arc-shaped slot, the larger the radius of a spraying area corresponding to the nozzle assemblies is. The closer the holders are to the circle center of the mounting ring, the smaller the distance between the two adjacent holders is. The closer the mounting positions of the holders on the arc-shaped slot are to the middle of the arc-shaped slot, the smaller the radius of the spraying area corresponding to the nozzle assemblies is.

Drawings described here are used to provide further understanding of the present disclosure and form a part of the present application. Illustrative embodiments of the present disclosure and description thereof are used for explaining the present disclosure, but do not improperly limit the present disclosure. In the drawings:.

The technical solutions provided in the present disclosure will be described in more detail below in conjunction with <FIG>.

Referring to <FIG> and <FIG>, some embodiments of the present disclosure provide a vibration exciting system, which includes a mounting ring <NUM>, a plurality of fixing parts <NUM>, a plurality of holders <NUM>, a plurality of guide rails <NUM>, and a plurality of nozzle assemblies <NUM>.

The mounting ring <NUM> is configured to be annular. The mounting ring <NUM> has a hole <NUM> in the middle. The fixing parts <NUM>, the holders <NUM>, the guide rails <NUM>, and the nozzle assemblies <NUM> are all located in the hole <NUM> in the middle of the mounting ring <NUM>. The diameter size of the mounting ring <NUM> is invariable. For aero-engines of different models, the diameter size of an area enclosed by the nozzle assemblies <NUM> is changed by adjusting the positions of the holders <NUM> on the fixing parts <NUM>, thereby adapting to the test requirements of the aero-engines of different models.

One ends of each fixing parts <NUM> are fixedly connected to the mounting ring <NUM>. The fixing parts <NUM> are, for example, rods. One ends of the fixing parts <NUM> are fixedly connected to the mounting ring <NUM>, such as detachable connection, undetachable connection (e.g., welding). The plurality of fixing parts <NUM> are mounted circumferentially of the mounting ring <NUM>, and each fixing part <NUM> is configured to mount one or more nozzle assemblies <NUM>. In the following embodiments, one nozzle assembly <NUM> is mounted on each fixing part <NUM>. The length direction of each fixing part <NUM> is along the radial direction of the mounting ring <NUM>.

The holders <NUM> are slidably mounted on the other ends of the fixing parts <NUM>, specifically by bolted connection, for example. The plurality of holders <NUM> are arranged circumferentially of the mounting ring <NUM>. The farther the holders <NUM> are from the circle center of the mounting ring <NUM>, the larger the radius of an area enclosed by the holders <NUM> is, and the larger the size of the corresponding aero-engine is. Conversely, the closer the holders <NUM> are to the circle center of the mounting ring <NUM>, the smaller the radius of the area enclosed by the holders <NUM> is, and the smaller the size of the corresponding aero-engine is. The radius size of the area enclosed by the holders <NUM> is adjusted by adjusting the positions of the holders <NUM> on the fixing parts <NUM>, thereby adapting to the test requirements of rotor systems <NUM> of aero-engines of different sizes, so as to adapt to the test requirements of vibration characteristics and damper vibration reduction effects of the engine rotor systems <NUM> of different models and sizes; and the adjustment process is convenient and fast.

Referring to <FIG>, in some embodiments, the holders <NUM> are uniformly arranged circumferentially of the mounting ring <NUM>. Each holder <NUM> is an arc segment. The plurality of holders <NUM> are uniformly spaced circumferentially of the mounting ring <NUM>. This achieves uniform oil spraying circumferentially of the mounting ring <NUM> as a test requires. In other embodiments, the nozzle assemblies <NUM> on some of the holders <NUM> dispense oil, and the nozzle assemblies <NUM> on the rest of the holders <NUM> do not dispense oil.

Referring to <FIG>, guide rail <NUM> connects two adjacent holders <NUM>, and connection positions of the guide rail <NUM> and the two adjacent holder <NUM> are adjustable. The guide rail <NUM> is connected to the holders <NUM> by bolts. By means of the guide rails <NUM>, a circle of holders <NUM> are fixedly connected together to improve the structural stability of the vibration exciting system, so that the nozzle assemblies <NUM> are securely mounted. The guide rails <NUM> are placed on the top surfaces of the holders <NUM> as shown in <FIG>, or on the bottom surfaces of the holders <NUM> as shown in <FIG> shows an example in which one of two adjacent guide rails <NUM> is placed on the top surfaces of the holders <NUM> and the other is placed on the bottom surfaces of the holders <NUM>. In this arrangement, the guide rails <NUM> occupy less space and the dimensions of the holders <NUM> are also designed to be as small as possible.

Referring to <FIG> and <FIG>, in some embodiments, the guide rail <NUM> is provided with an arc-shaped slot <NUM>, one of the two adjacent holders <NUM> being connected to one end of the arc-shaped slot <NUM> in a position adjustable manner, and the other of the two adjacent holders <NUM> being connected to the other end of the arc-shaped slot <NUM> also in a mounting position adjustable manner. The closer the holders <NUM> are to the edge of the mounting ring <NUM>, the greater the distance between the two adjacent holders <NUM> is. The closer the mounting positions of the holders <NUM> on the arc-shaped slot <NUM> are to the edge of the arc-shaped slot <NUM>. The closer the holders <NUM> are to the circle center of the mounting ring <NUM>, the smaller the distance between the two adjacent holders <NUM> is, and the closer the mounting positions of the holders <NUM> on the arc-shaped slot <NUM> are to the middle of the arc-shaped slot <NUM>.

Referring to <FIG>, the nozzle assemblies <NUM> are mounted on the holders <NUM>. The nozzle assemblies <NUM> are configured to spray lubricating oil. Each nozzle assembly <NUM> includes one or more nozzles <NUM>. The nozzles <NUM> included in the nozzle assembly <NUM> use a known atomization structure.

Referring to <FIG>, the nozzle assembly <NUM> includes a mounting seat <NUM> and nozzles <NUM>. The mounting seat <NUM> is mounted on the holder <NUM>. The nozzles <NUM> are rotatably mounted on the mounting seat <NUM>. The structure of the mounting seat <NUM> is, for example, stereoscopic or cuboidal. The mounting base <NUM> as the base for carrying the nozzles <NUM> is flexible in structural design.

Referring to <FIG>, in some embodiments, there are a plurality of mounting seats <NUM>, and the plurality of mounting seats <NUM> are arranged around an inner circle of the mounting ring <NUM>. The plurality of mounting seat <NUM> enclose a circle, and at least some areas of rotor blades to be sprayed are located within the circle enclosed by the mounting seats <NUM>. A plurality of nozzle assemblies <NUM> are mounted rotatably on each mounting seat <NUM>. Specifically, for example, a ball joint <NUM> is used to achieve rotatable connection so that each nozzle <NUM> is flexibly rotated at an angle to achieve an adjustable oil spraying angle of each nozzle <NUM>. Moreover, the oil spraying angle of each nozzle <NUM> is adjusted individually, and the oil spraying directions of the nozzles <NUM> located on the same mounting seat <NUM> is same or different. The oil spraying directions of the nozzles <NUM> point to the circle center of the mounting ring <NUM>, or do not point to the circle center of the mounting ring <NUM>, as long as the nozzles <NUM> spray oil to the rotor blades. Thus, for turbine rotor blades with flexural and torsional surfaces of blade bodies, vibration excitation is also achieved effectively for the blade bodies. Moreover, by adjusting the oil dispensing angles of the nozzles <NUM>, angles more favorable to the excitation of blade resonance are obtained, and the adjustment of the range of atomized oil excited to the blade bodies is also achieved.

Referring to <FIG> and <FIG>, in some embodiments, the mounting seat <NUM> includes an oil supply cavity <NUM>. The oil supply cavity <NUM> is located as shown in <FIG>. All nozzles <NUM> corresponding to one mounting seat <NUM> share an oil supply cavity <NUM>, or each nozzle <NUM> is provided with an oil supply cavity <NUM> respectively, or some of all nozzles <NUM> corresponding to one mounting seat <NUM> share an oil supply cavity <NUM>. The nozzle assembly <NUM> further includes a switching valve <NUM>. The switching valve <NUM> is provided between the nozzles <NUM> and the oil supply cavity <NUM> of the mounting seat <NUM> to control the on and off of oil passages between the nozzles <NUM> and the oil supply cavity <NUM>. The switching valve <NUM> is, for example, a solenoid valve, and the switching valve <NUM> has two valve positions: an on-valve position and an off-valve position. When the switching valve <NUM> is in the on-valve position, the oil passages between the nozzles <NUM> and the oil supply cavity <NUM> are turned on, such that oil flows from the oil supply cavity <NUM> to the nozzles <NUM> and then be sprayed out via the nozzles <NUM>. When the switching valve <NUM> is in the off-valve position, the oil passages between the nozzles <NUM> and the oil supply cavity <NUM> are turned off, such that oil don't flow from the oil supply cavity <NUM> to the nozzles <NUM>. The volume of the oil supply cavity <NUM> is greater than the sum of flow areas of the nozzles <NUM> communicated with the oil supply cavity <NUM>.

Referring to <FIG>, <FIG> and <FIG>, in some embodiments, the vibration exciting system further includes an oil supply branch <NUM>. The oil supply branch <NUM> is in fluid communication with the oil supply cavity <NUM>, and the oil supply branch <NUM> is configured to convey external oil to the oil supply cavity <NUM> to be sprayed by the nozzles <NUM> in fluid communication with the oil supply cavity <NUM>. Specifically, one end of the oil supply branch <NUM> is in fluid communication with an external oil circuit <NUM>, and the other end of the oil supply branch <NUM> is in fluid communication with the nozzles <NUM>. To facilitate the arrangement of the oil supply branch <NUM>, the holder <NUM> is provided with a mounting hole <NUM>, and a pipeline of the oil supply branch <NUM> passes through the mounting hole <NUM>.

The external oil circuit includes a plurality of oil pipes <NUM> and an oil supply and return system <NUM>. Oil is conveyed from the oil supply and return system <NUM> to the oil supply branch <NUM> through some oil pipes <NUM>, and the used oil is recovered and then conveyed back to the oil supply and return system <NUM> via other oil pipes <NUM>. The oil supply and return system <NUM> achieves recycling of the oil.

Referring to <FIG>, in some embodiments, the switching valve <NUM> is provided on the oil passage between each nozzle <NUM> and the oil supply cavity <NUM>. This achieves separate control of each nozzle <NUM>. During testing, among a circle of nozzles <NUM> of the vibration exciting system, some spray oil, while the others do not spray oil. These oil spraying nozzles <NUM> are adjacent to or spaced apart from each other, or some are adjacent and some are spaced apart. Of course, in some embodiments the circle of nozzles <NUM> all spray oil.

Since the number of the oil spraying nozzles <NUM> is related to a rotational speed of the rotor system <NUM> and a frequency of the rotor blades, further, according to the operating speed of the rotor system <NUM> and a frequency range of the blades, the nozzle assembly <NUM> enables a corresponding number of nozzles <NUM> to spray oil, and the oil supplying nozzles <NUM> are spaced apart by the same distance to ensure that each blade obtains the same amount of excited oil and pressure, such that the amount of oil spraying excitation can be adjusted on an apparatus to adapt to a vibration test of the same rotor system <NUM> at different rotational speeds. Under the condition of high-speed rotation, the excitation frequency for exciting the rotor blades of the engine needs to satisfy the following equation: <MAT>.

In the formula, F is the excitation frequency in Hz; N is the number of nozzles; and n is the rotational speed in r/m.

In the above technical solution, during testing, the number of the oil dispensing nozzles <NUM> is adjusted according to different rotational speeds of the engine, specifically in such a manner that, for example, all the nozzles <NUM> on some mounting seats <NUM> dispense oil, or all the nozzles <NUM> on all mounting seats <NUM> dispense oil, or only some of the nozzles <NUM> on each mounting seat <NUM> dispense oil, or for a circle of nozzles <NUM>, the nozzles <NUM> dispense oil in a spaced manner, i.e. one nozzle <NUM> that does not dispense oil is sandwiched between two oil dispensing nozzles <NUM>. For these oil dispensing nozzles <NUM>, the oil dispensing angle of each nozzle <NUM> is adjusted individually very conveniently. Moreover, for the same rotor blades to be tested, a test is repeated several times, and the number and positions of the oil dispensing nozzles <NUM> are also optimally adjusted according to test results to achieve the best test results. For rotor blades of different models, the number and positions of the nozzles <NUM> that need to dispense oil are also adjusted separately. It can be seen that the above technical solution achieves the test repeatability and the test accuracy, but also achieves flexible setting of test conditions.

Referring to <FIG>, some embodiments of the present disclosure further provide an apparatus for testing an aero-engine rotor, including the vibration exciting system provided in any technical solution of the present disclosure.

An aero-engine is a highly complex and sophisticated thermodynamic machine that provides power for the flight of an aircraft. The rotor is a rotating body supported by a bearing. Vibration refers to reciprocating motion, and the vibration is closely related to its own frequency, excitation frequency, and excitation magnitude. The apparatus for testing an aero-engine rotor is used to test the vibration and a damper vibration reduction effect of the rotor system <NUM> in a high-speed rotating state.

Referring to <FIG> and <FIG>, in some embodiments, the apparatus for testing an aero-engine rotor further includes a test cavity <NUM>, a rotor system <NUM>, and a driving component <NUM>. The vibration exciting system is installed within the test cavity <NUM>. The rotor system <NUM> is also mounted within the test cavity <NUM>, and the vibration exciting system is located on the circumferential outside of the rotor system <NUM>. The driving component <NUM> is drivingly connected to the rotor system <NUM> to drive the rotor system <NUM> to rotate. The driving component <NUM> is, for example, a motor. The motor is arranged outside the test cavity <NUM> and transmits power to the rotor system <NUM> through a transmission shaft.

The rotor system <NUM> of a high-pressure turbine includes rotor blades <NUM> and a disc <NUM>. The frequency of the rotor blades <NUM> is very high, and the rotor blades <NUM> are connected to the wheel disc <NUM> by means of a tongue-and-groove non-linear connection structure. The resonant frequency of the rotor blades <NUM> and the vibration reduction effect of a damper are tested in a real high-speed rotating state, which is closer to centrifugal load conditions during engine operation, achieves the non-linear connection structure of the rotor blades <NUM>, and frictional motion of the damper and rotor blades <NUM>, and obtains more reliable test data. The excitation mode at the high-speed rotating state, that is, implementing atomized oil excitation of the rotor blades <NUM> on a high-speed rotating test bed, is a practical and feasible way that excites an effective response from high-frequency blades.

In description of the present disclosure, it should be understood that orientation or position relations denoted by the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are orientation or position relations illustrated based on the drawings, are merely for the convenience of describing the present disclosure and simplifying description, instead of indicating or implying the denoted devices or elements must have specific orientations or be constructed and operated in specific orientations, and thus the terms cannot be construed as limiting the protection scope of the present disclosure.

Claim 1:
A vibration exciting system, comprising:
a mounting ring (<NUM>), configured to be annular;
a plurality of fixing parts (<NUM>), each having one end fixedly connected to the mounting ring (<NUM>); a length direction of each fixing part (<NUM>) is along a radial direction of the mounting ring (<NUM>);
a plurality of holders (<NUM>), each slidably mounted at the other end of each of the fixing parts (<NUM>), the plurality of holders (<NUM>) being arranged circumferentially of the mounting ring (<NUM>);
and characterised in that the vibration exciting system further comprises:
a plurality of guide rails (<NUM>), each connecting two adjacent holders (<NUM>), wherein connection positions of each of the guide rails (<NUM>) and the two adjacent holder (<NUM>) being adjustable; and
a plurality of nozzle assemblies (<NUM>), are mounted on the holders (<NUM>) respectively.