Single-shaft centrifuge experimental device with floating support reaction force and shaft center trajectory measurement function

Abstract

The present application relates to centrifugal test equipment, rotating machinery state detection and dynamic balance experimental device technical field, specifically speaking, a single-shaft centrifuge experimental device with floating support reaction force and shaft locus measurement function is provided with a detection mechanism, the detection mechanism is arranged above the fixed support assembly, four S type tension and compression force sensors are arranged in pairs along the first direction and the second direction perpendicular to each other, one end of each S type tension and compression force sensor is connected with the floating bearing seat through the fish eye bearing, the other end is connected with the mounting plate through the adjusting block and is pre-tightened by the adjusting nut; the measuring axes of the two eddy current displacement sensors are perpendicular to each other and face the radial measurement surface of the main shaft, so that the support reaction force of the floating bearing seat and the two-direction horizontal displacement of the main shaft can be measured synchronously.

Description

Technical Field

[0001] This invention relates to the technical field of centrifuge testing equipment, rotating machinery condition detection and dynamic balancing experimental devices. Specifically, it is a single-axis centrifuge experimental device that integrates fixed load-bearing support, floating support reaction force measurement, spindle centerline trajectory measurement and adjustable unbalanced loading at the rotating end into the same platform, and has the functions of floating support reaction force and spindle centerline trajectory measurement. Background Technology

[0002] Rotary arm centrifuges use a vertical spindle to rotate the arm and its end load, creating a controllable centrifugal load environment. Due to factors such as load eccentricity in the experimental chamber, counterweight errors, manufacturing errors in the rotating arm, misalignment of the assembly shafts, bearing support deviations, and uneven mass distribution of the rotating liquid, the rotating arm-spindle system is prone to dynamic imbalance excitation at the same frequency as the rotational speed. This excitation is transmitted along the rotating arm, spindle, and bearing housing to the frame, causing fluctuations in support reaction force, an expansion of the spindle's centerline trajectory, increased bearing load, and enhanced overall machine vibration.

[0003] Most existing laboratory centrifuges use upper and lower rigid bearing seats for support. Rigid support is beneficial for obtaining higher structural rigidity, but after the bearing seats are constrained by the frame, it is difficult to directly measure the two-directional reaction forces formed by unbalanced loads at the support. When only accelerometers are placed on the surface of the frame or bearing seats, the detection results are also affected by the frame mode, sensor position and external vibration.

[0004] Using two non-contact displacement sensors to measure the lateral displacement of the spindle can obtain the spindle center trajectory. However, the spindle center trajectory is affected by the spindle bending stiffness, support stiffness, damping, and bearing self-aligning characteristics, and cannot reflect the actual reaction force transmitted at the support alone. To study the transmission law of unbalanced forces, the correspondence between reaction force and trajectory, and the effect of different balancing strategies, it is still necessary to obtain the support reaction force, spindle displacement, key phase, and transmission torque simultaneously on the same experimental platform.

[0005] In addition, the conventional method of manually adding or removing counterweights to adjust the imbalance of the centrifuge is discrete and has limited repeatability; although setting adjustable liquid mass units on both sides of the rotating arm can continuously change the mass distribution, there are still problems with oil supply and return and signal transmission between the fixed end hydraulic source and the rotating end actuator.

[0006] In summary, existing single-axis rotary arm centrifuge experimental devices cannot simultaneously take into account axial load, direct measurement of lateral support reaction force, synchronous measurement of spindle center trajectory, acquisition of key phase reference, and adjustable unbalanced state construction. This makes it difficult to verify the mechanical transmission path of unbalanced load, lacks cross-verification between reaction force and trajectory, and makes it difficult to repeat experiments on detection and control algorithms under different unbalance levels. Summary of the Invention

[0007] This invention addresses the shortcomings and deficiencies of existing technologies by proposing a single-axis centrifuge experimental device that enables a fixed support to bear the main axial load and radial guidance, while allowing another support to perform bidirectional force measurement within a controlled micro-displacement range. Simultaneously, it measures the spindle centerline trajectory and key phase, and reserves hydraulic mass adjustment capability at the rotating end. This provides a structurally unified and repeatable experimental object with floating support reaction force and spindle centerline trajectory measurement functions for unbalance detection, calibration, hydraulic adjustment, and control method verification.

[0008] This invention achieves its purpose through the following measures: A single-axis centrifuge experimental device with floating support reaction force and axis trajectory measurement functions is provided, comprising a frame, a motor (2), a transmission assembly, a main shaft (7), a rotating arm, an experimental chamber (15), a counterweight chamber (16), a fixed support assembly, and a detection mechanism (17). The motor (2) is connected to the main shaft (7) through the transmission assembly. The rotating arm is disposed at the upper end of the main shaft (7). The experimental chamber (15) and the counterweight chamber (16) are respectively disposed at both ends of the rotating arm. The detection mechanism (17) is characterized in that: the detection mechanism (17) is disposed above the fixed support assembly, and the detection mechanism (17) includes a mounting plate (18), a floating bearing seat (8), and a device disposed within the floating bearing seat (8) and sleeved on the main shaft (7). 7) The outer self-aligning ball bearing (22), four S-type tension and compression sensors (9) and two eddy current displacement sensors (10); the four S-type tension and compression sensors (9) are arranged in pairs along a first direction and a second direction that are perpendicular to each other. One end of each S-type tension and compression sensor (9) is connected to the floating bearing seat (8) through a fisheye bearing (21), and the other end is connected to the mounting plate (18) through an adjusting block (19) and pre-tightened by an adjusting nut (20); the measuring axes of the two eddy current displacement sensors (10) are perpendicular to each other and face the radial measuring surface of the main shaft (7) so that the support reaction force of the floating bearing seat (8) and the lateral displacement of the main shaft (7) in two directions can be measured synchronously.

[0009] The transmission assembly of the present invention includes a first diaphragm coupling (3), a torque sensor (4), and a second diaphragm coupling (5) arranged sequentially along the power transmission direction. The first diaphragm coupling (3) is connected to the output end of the motor (2), and the second diaphragm coupling (5) is connected to the main shaft (7).

[0010] The fixed support assembly described in this invention includes a fixed bearing housing, a self-aligning ball bearing (22) sleeved on the outside of the main shaft (7), and a one-way thrust ball bearing (25) with a spherical race located below the self-aligning ball bearing (22). The self-aligning ball bearing (22) is used for radial guidance and angular deviation compensation of the main shaft, and the one-way thrust ball bearing (25) with a spherical race is used to bear the axial load generated by the main shaft, the rotating arm, the experimental chamber (15), the counterweight chamber (16), and the hydraulic cylinder (14).

[0011] In this invention, an upper and lower plate coaxial positioning connector (23) is provided between the upper mounting plate where the detection mechanism (17) is located and the lower mounting plate where the fixed support assembly is located. The upper and lower plate coaxial positioning connector (23) is arranged around the main shaft (7) and is used to maintain the coaxial installation reference of the floating support and the fixed support. A mechanical limiting structure is provided between the mounting plate (18) and the floating bearing seat (8) to limit the maximum lateral displacement of the floating bearing seat (8). The limiting gap of the mechanical limiting structure is greater than the floating displacement under normal measurement conditions and less than the displacement corresponding to the contact between the eddy current displacement sensor (10) and the main shaft (7).

[0012] In this invention, four S-shaped tension and compression sensors (9) are respectively arranged in the positive first direction, negative first direction, positive second direction and negative second direction of the floating bearing seat (8). The rotation center of the fisheye bearing (21) intersects with the force axis of the corresponding S-shaped tension and compression sensor (9) to reduce the additional bending moment caused by the installation deviation. The two eddy current displacement sensors (10) are set at a preset installation angle relative to the first direction and the second direction, and a probe bracket that can adjust the gap between the probe and the measuring surface of the main shaft (7) is provided between the two eddy current displacement sensors (10) and the mounting plate (18).

[0013] The main shaft (7) of the present invention is provided with a photoelectric sensor (11) around its periphery. The main shaft (7) or a component that rotates synchronously with the main shaft (7) is provided with a photoelectric sensor groove plate (24). The photoelectric sensor (11) and the photoelectric sensor groove plate (24) cooperate to generate at least one key phase pulse per revolution.

[0014] The present invention has hydraulic cylinders (14) located on both sides of the main shaft (7) on the rotating arm. Each hydraulic cylinder (14) includes a hydraulic oil chamber, a gas back pressure chamber and a piston separating the two chambers. The volume difference of the hydraulic oil chambers of the two hydraulic cylinders (14) is used to form an adjustable liquid mass difference. The experimental chamber (15), the counterweight chamber (16) and the hydraulic cylinders (14) are all fixed on the rotating arm by an anti-loosening connection structure. The frame is provided with a protective structure covering the rotating area of ​​the rotating arm. An electro-hydraulic slip ring (12) is coaxially arranged on the outside of the main shaft (7). The electro-hydraulic slip ring (12) includes a hydraulic oil supply channel, a hydraulic oil return channel and an electrical signal channel. The hydraulic oil supply channel and the hydraulic oil return channel connect the hydraulic source at the fixed end and the hydraulic cylinder (14) at the rotating end. The electrical signal channel is used to transmit pressure, displacement or status signals.

[0015] The present invention also includes a synchronous acquisition mechanism, which is electrically connected to four S-shaped tension and compression sensors (9), two eddy current displacement sensors (10), a photoelectric sensor (11) and a torque sensor (4).

[0016] Compared with the prior art, the present invention separates the functions of fixed support and floating detection support, so that the fixed support bears the main axial load and radial guidance, and the floating support bears the bidirectional reaction force detection, thereby reducing the mutual interference between load bearing and force measurement functions from the structure.

[0017] This invention uses four S-shaped tension and compression sensors (9) arranged in pairs along two orthogonal directions, and forms a preloadable, low-addition-moment force measurement connection through adjusting blocks (19), adjusting nuts (20), and fisheye bearings (21). This allows for the acquisition of dynamic reaction force changes in different directions and facilitates the use of opposing channels to differentially reduce the effects of common preload and temperature drift. By combining two eddy current displacement sensors (10) with a photoelectric sensor (11), the lateral displacement of the main shaft, the shaft center trajectory, and the phase relative to the key phase can be acquired synchronously, thereby enabling cross-checking with the floating support reaction force. The self-aligning ball bearing (22) can compensate for certain assembly angle errors, the unidirectional thrust ball bearing (25) with spherical seat ring concentrates the axial load, and the coaxial positioning connector (23) of the upper and lower plates is conducive to maintaining the coaxiality of the two-stage support; the hydraulic cylinder (14) and electro-hydraulic slip ring (12) can continuously change the mass distribution of the liquid on both sides during rotation, so that the experimental device can repeatedly construct unbalanced states of different amplitudes, which is suitable for dynamic unbalance detection, sensor calibration, balance adjustment and control algorithm verification; in addition, by setting mechanical limit structure, anti-loosening connection and rotating arm protection structure, the collision risk caused by extreme imbalance, sensor loosening or abnormal probe gap can be reduced.

[0018] Compared with the prior art, this invention enables the fixed support to bear the main axial load and radial guidance, while the other support completes bidirectional force measurement within a controlled micro-displacement range. Simultaneously, it measures the spindle centerline trajectory and key phase, and reserves the hydraulic mass adjustment capability of the rotating end. Thus, it provides a structurally unified and repeatable experimental object with floating support reaction force and spindle centerline trajectory measurement function for unbalance detection, calibration, hydraulic adjustment and control method verification. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the single-axis centrifuge experimental device of the present invention.

[0020] Figure 2 This is a schematic diagram of the overall front view of the single-axis centrifuge experimental device of the present invention.

[0021] Figure 3 This is a partial three-dimensional structural diagram of the floating detection component of the present invention.

[0022] Figure 4 This is a top view of the floating detection component of the present invention.

[0023] Figure 5 This is an axial sectional view of the fixed support assembly, floating bearing housing, and main shaft of the present invention.

[0024] Figure 6 This is a partial structural schematic diagram of the photoelectric sensor and the photoelectric sensor groove plate of the present invention.

[0025] Figure 7 This is a partial structural diagram of the drive transmission assembly of the present invention.

[0026] Figure 8 This is a schematic diagram showing the arrangement of the S-type tension / compression sensor and the eddy current displacement sensor relative to the main shaft of the present invention.

[0027] Figure 9 This is a partial schematic diagram of the S-type tension / compression sensor, fisheye bearing, and preload adjustment structure of the present invention.

[0028] Reference numerals: Rotary arm (1), Motor (2), First diaphragm coupling (3), Torque sensor (4), Second diaphragm coupling (5), Drive transmission assembly (6), Main shaft (7), Floating bearing seat (8), S-type tension and compression sensor (9), Eddy current displacement sensor (10), Photoelectric sensor (11), Electro-hydraulic slip ring (12), Hydraulic cylinder (14), Experimental chamber (15), Counterweight chamber (16), Detection mechanism (17), Mounting plate (18), S-type tension and compression sensor adjusting block (19), Adjusting nut (20), Fish eye bearing (21), Self-aligning ball bearing (22), Upper and lower plate coaxial positioning connector (23), Photoelectric sensor groove plate (24), 53210U unidirectional thrust ball bearing with spherical seat ring (25). Detailed Implementation

[0029] Existing single-axis rotary centrifuge experimental devices cannot simultaneously take into account axial load, direct measurement of lateral support reaction force, synchronous measurement of spindle center trajectory, acquisition of key phase reference, and adjustable unbalanced state construction. This makes it difficult to verify the mechanical transmission path of unbalanced load, lacks cross-checking between reaction force and trajectory, and makes it difficult to repeat experiments on detection and control algorithms under different unbalance levels.

[0030] To solve the above-mentioned technical problems, the present invention provides a single-axis centrifuge experimental device, including a frame, a drive transmission assembly (6), a main shaft (7), a rotating arm (1), an experimental chamber, a counterweight chamber, a fixed support assembly, and a floating detection assembly. The drive transmission assembly (6) is located at the lower part of the frame. The main shaft (7) passes through the fixed support assembly and the floating detection assembly in the vertical direction. The rotating arm is fixed at the upper end of the main shaft. The experimental chamber and the counterweight chamber are located at both ends of the rotating arm, respectively. The fixed support assembly bears the main axial load and radial guidance. The floating detection assembly simultaneously realizes bidirectional support reaction force measurement and main shaft lateral displacement measurement within a controlled micro-displacement range.

[0031] The drive transmission assembly preferably includes a motor (2), a first diaphragm coupling (3), a torque sensor (4), and a second diaphragm coupling (5). The two diaphragm couplings are used to compensate for minor axial, radial, and angular assembly deviations, and the torque sensor (4) is used to monitor the transmission load during start-up, speed equalization, and hydraulic regulation processes.

[0032] The fixed support assembly is located at the lower part of the spindle and includes a fixed bearing housing, a self-aligning ball bearing (22), and a one-way thrust ball bearing (25) with a spherical race. The self-aligning ball bearing (22) provides radial guidance for the spindle (7) and allows for small-angle self-alignment, while the one-way thrust ball bearing (25) with a spherical race bears the axial load generated by the spindle, the rotating arm, and the upper components.

[0033] The floating detection assembly constitutes the detection mechanism (17), including a mounting plate (18), a floating bearing housing (8), a self-aligning ball bearing (22) disposed in the floating bearing housing (8), four S-type tension and compression sensors (9), two eddy current displacement sensors (10), an adjusting block (19), an adjusting nut (20), and a fisheye bearing (21). The floating bearing housing (8) is not directly and rigidly fixed to the mounting plate (18), but is pre-tightened by four S-type tension and compression sensors (9) in two mutually perpendicular directions. One end of each S-type tension and compression sensor (9) is connected to the floating bearing housing (8) through the fisheye bearing (21), and the other end is connected to the mounting plate (18) through the adjusting block (19) and the adjusting nut (20). The fisheye bearing (21) allows the connection end to swing at a small angle to reduce the bending moment introduced by assembly deviation; the adjusting block (19) and the adjusting nut (20) are used to adjust the initial preload of the four force measuring branches.

[0034] Two eddy current displacement sensors (10) are set around the floating bearing housing (8), with the measuring axes perpendicular to each other and facing the smooth cylindrical measuring surface of the main shaft (7). Depending on the actual installation space, the two measuring axes can coincide with the force measuring direction or be rotated by a preset angle relative to the force measuring direction; the displacement in two directions in the structural coordinate system can be obtained through subsequent coordinate transformation.

[0035] A photoelectric sensor (11) is disposed on the periphery of the spindle (7) and cooperates with the photoelectric sensor groove plate (24) to generate a key phase pulse. The key phase pulse is used to determine the reference angle of the spindle per revolution, so that the reaction force, shaft center trajectory and torque signals can be compared under a unified angular coordinate system.

[0036] A coaxial positioning connector (23) is provided between the upper and lower mounting plates to ensure that the floating support and the fixed support are installed around the same main shaft axis. A mechanical limiting structure is also provided around the floating bearing seat (8) to limit lateral displacement under extreme imbalance conditions and protect the eddy current displacement sensor (10).

[0037] Hydraulic cylinders (14) symmetrical to the main shaft (7) can be installed on the rotating arm. Each hydraulic cylinder (14) consists of a hydraulic oil chamber, a gas back pressure chamber, and a piston. By changing the effective oil volume of the hydraulic oil chambers on both sides, a continuously adjustable liquid mass difference can be formed on both sides of the rotating arm; the gas back pressure chamber is used to provide flexible back pressure and buffering effect.

[0038] The electro-hydraulic slip ring (12) is coaxially arranged with the spindle (7) and is used to establish a hydraulic supply, return and electrical signal channel between the fixed end hydraulic source and the rotating end hydraulic cylinder (14). Example

[0039] This example relates to a centrifuge experimental apparatus, disclosing a single-axis centrifuge experimental apparatus with floating support reaction force and shaft center trajectory measurement functions. The apparatus includes a motor, transmission assembly, main shaft, floating bearing housing, four S-shaped tension / compression sensors, two eddy current displacement sensors, a photoelectric sensor, an electro-hydraulic slip ring, a hydraulic cylinder, an experimental chamber, and a counterweight chamber. The floating bearing housing forms an orthogonal preload constraint with the mounting plate via the four S-shaped tension / compression sensors, and the two eddy current displacement sensors measure the lateral displacement of the main shaft. The fixed support assembly utilizes self-aligning ball bearings and thrust ball bearings to achieve radial guidance and axial load bearing. This apparatus can simultaneously obtain the floating support reaction force and shaft center trajectory, and can be used for controlled unbalanced loading, detection calibration, and dynamic balancing tests.

[0040] This example Figure 1 and Figure 2 As shown, the frame consists of a base plate, columns, an intermediate bearing plate, an upper mounting plate, and connecting components. The motor (2) is fixed to the lower part of the frame, and the output shaft of the motor (2) is connected to the main shaft (7) via a first diaphragm coupling (3), a torque sensor (4), and a second diaphragm coupling (5). The main shaft (7) is arranged vertically, and a rotating arm is fixedly connected to its upper end. The two ends of the rotating arm are connected to the experimental chamber (15) and the counterweight chamber (16), respectively. A hydraulic cylinder (14) is also installed on the rotating arm.

[0041] The motor (2) can be a motor with a reducer to provide low-speed, high-torque output. The first diaphragm coupling (3) and the second diaphragm coupling (5) are respectively set on both sides of the torque sensor (4), which not only transmit torque but also compensate for the slight misalignment between the motor output shaft, the torque sensor (4) and the main shaft (7). The torque sensor (4) is mounted in the middle of the frame by a bracket, and its housing prevents it from rotating with the shaft.

[0042] like Figure 5 As shown, the main shaft (7) passes through the upper floating support and the lower fixed support in sequence. The upper self-aligning ball bearing (22) is installed in the floating bearing housing (8), and the lower self-aligning ball bearing (22) and the one-way thrust ball bearing (25) with spherical raceway together form the fixed support. The one-way thrust ball bearing (25) with spherical raceway is preferably of type 53210U, and the self-aligning ball bearing (22) is preferably of type 2210; the above models are only one embodiment.

[0043] The lower self-aligning ball bearing (22) provides radial guidance to the main shaft (7). Its outer ring is positioned by a fixed bearing housing, and its inner ring mates with the main shaft (7) through a shoulder, spacer, and locking element. The seat ring of the spherical thrust ball bearing (25) is supported on a fixed bearing surface. The bearing ring rotates with the main shaft (7) or the bearing sleeve connected to the main shaft to bear the axial gravity and operating load of the upper rotating assembly.

[0044] The outer ring of the self-aligning ball bearing (22) in the upper floating bearing housing (8) is axially limited by the seat bore step and the pressure cap, while the inner ring rotates with the spindle (7). Here, "floating" refers to the controlled slight lateral displacement of the floating bearing housing (8) as a whole relative to the mounting plate (18), rather than the outer ring of the self-aligning ball bearing (22) moving freely within the seat bore.

[0045] like Figure 3 , Figure 4 and Figure 9 As shown, four S-shaped tension / compression sensors (9) are arranged around a floating bearing seat (8). The inner end of each S-shaped tension / compression sensor (9) is connected to the floating bearing seat (8) via a fisheye bearing (21), and the outer end is connected to an adjusting block (19), which is fixed on a mounting plate (18). Rotating the adjusting nut (20) can change the length of the corresponding force measuring branch, thereby setting the preload.

[0046] The four force measuring branches are preferably set along the X and Y orthogonal directions of the structure. During assembly, the main shaft (7) is first placed in the reference position without external load, and then the four adjusting nuts (20) are adjusted in sequence to ensure that the S-shaped tension and compression sensors (9) in opposite directions are all kept in positive preload and the preload values ​​are close. Then, each channel is calibrated by static load in a known direction.

[0047] When the spindle (7) applies a lateral load to the floating bearing housing (8) due to the imbalance of the rotating arm, the floating bearing housing (8) produces a small displacement, causing the output of the two S-shaped tension and compression sensors (9) in the corresponding directions to change, one increasing and the other decreasing. The reaction force component of the floating support can be reconstructed by differentially analyzing the opposing sensors.

[0048] like Figure 8 As shown, the measuring axes of the two eddy current displacement sensors (10) are perpendicular to each other, preferably arranged at approximately 45 degrees relative to the X and Y directions, to avoid the four S-shaped tension and compression sensors (9) and their connecting structures. A working gap is left between the probe and the measuring surface of the main shaft (7), and radial and axial positioning is achieved through an adjustable bracket.

[0049] like Figure 6 As shown, the photoelectric sensor (11) is mounted on a fixed component, and the photoelectric sensor groove plate (24) rotates synchronously with the main shaft (7). The photoelectric sensor groove plate (24) is provided with notches, light-transmitting slots, or reflective marks, so that the photoelectric sensor (11) generates a pulse at a predetermined angular position per revolution. This pulse can serve as a first-harmonic phase reference for the reaction force and displacement signals.

[0050] like Figure 5As shown, a coaxial positioning connector (23) is provided between the upper and lower mounting plates. This connector can be a coaxial sleeve, a positioning sleeve, or an intermediate support with a flange, with its center hole coaxial with the main shaft (7), used to determine the positions of the upper and lower supports during the assembly stage. The connector does not restrict the small measurement displacement of the floating bearing seat (8) in the plane of the mounting plate (18).

[0051] Hydraulic cylinders (14) are mounted on both sides of the main shaft (7) along the length of the swing arm. The outer cavity of each hydraulic cylinder (14) is a hydraulic oil cavity, and the inner cavity is a gas back pressure cavity. By controlling the oil volume or piston position of the left and right hydraulic oil cavities, a liquid mass difference in a known direction can be formed. The gas back pressure cavity can be filled with nitrogen to provide a flexible restoring force to the piston and reduce the oil supply and return shock.

[0052] The electro-hydraulic slip ring (12) can be a coaxial combination of a hydraulic rotary joint and an electric slip ring. The oil supply, oil return and electrical signals at the fixed end are transmitted to the hydraulic cylinder (14) and related sensors at the rotating end via the electro-hydraulic slip ring (12), which avoids the entanglement of pipelines and wires when the boom rotates continuously.

[0053] Before the experiment, check the anti-loosening structure of the experimental chamber (15), counterweight chamber (16), and hydraulic cylinder (14), adjust the pre-tightening of the S-type tension and compression sensor (9), set the probe gap of the eddy current displacement sensor (10), and record the key phase of the photoelectric sensor (11). After confirming no interference during low-speed operation, gradually increase the rotation speed and collect the support reaction force, shaft trajectory, key phase, and torque signals.

[0054] In this embodiment, an S-type tension and compression sensor and an eddy current displacement sensor are used, but they can be replaced by other force sensors that can measure axial force in a pre-tightened state and other non-contact displacement sensors that can measure the lateral displacement of the spindle, respectively; the fisheye bearing (21) can also be replaced by a spherical bearing, ball joint or flexible hinge.

[0055] Compared with the prior art, this invention enables the fixed support to bear the main axial load and radial guidance, while the other support completes bidirectional force measurement within a controlled micro-displacement range. Simultaneously, it measures the spindle centerline trajectory and key phase, and reserves the hydraulic mass adjustment capability of the rotating end. Thus, it provides a structurally unified and repeatable experimental object with floating support reaction force and spindle centerline trajectory measurement function for unbalance detection, calibration, hydraulic adjustment and control method verification.

Claims

1. A single-axis centrifuge experimental device with floating support reaction force and shaft center trajectory measurement function, comprising a frame, a motor (2), a transmission assembly, a main shaft (7), a rotating arm, an experimental chamber (15), a counterweight chamber (16), a fixed support assembly, and a detection mechanism (17), wherein the motor (2) is connected to the main shaft (7) through the transmission assembly, the rotating arm is disposed at the upper end of the main shaft (7), and the experimental chamber (15) and the counterweight chamber (16) are respectively disposed at both ends of the rotating arm, characterized in that: The detection mechanism (17) is located above the fixed support assembly. The detection mechanism (17) includes a mounting plate (18), a floating bearing seat (8), a self-aligning ball bearing (22) located inside the floating bearing seat (8) and sleeved on the outside of the main shaft (7), four S-type tension and compression sensors (9), and two eddy current displacement sensors (10). The four S-type tension and compression sensors (9) are arranged in pairs along a first direction and a second direction that are perpendicular to each other. One end of each S-type tension and compression sensor (9) is connected to the floating bearing seat (8) through a fisheye bearing (21), and the other end is connected to the mounting plate (18) through an adjusting block (19) and is pre-tightened by an adjusting nut (20). The measuring axes of the two eddy current displacement sensors (10) are perpendicular to each other and face the radial measuring surface of the main shaft (7) so that the support reaction force of the floating bearing seat (8) and the lateral displacement of the main shaft (7) in two directions can be measured synchronously.

2. The single-axis centrifuge experimental device with floating support reaction force and shaft center trajectory measurement function according to claim 1, characterized in that: The transmission assembly includes a first diaphragm coupling (3), a torque sensor (4), and a second diaphragm coupling (5) arranged sequentially along the power transmission direction. The first diaphragm coupling (3) is connected to the output end of the motor (2), and the second diaphragm coupling (5) is connected to the main shaft (7).

3. The single-axis centrifuge experimental device with floating support reaction force and shaft center trajectory measurement function according to claim 1, characterized in that: The fixed support assembly includes a fixed bearing housing, a self-aligning ball bearing (22) sleeved on the outside of the main shaft (7), and a one-way thrust ball bearing (25) with a spherical race located below the self-aligning ball bearing (22). The self-aligning ball bearing (22) is used for radial guidance and angular deviation compensation of the main shaft, and the one-way thrust ball bearing (25) with a spherical race is used to bear the axial load generated by the main shaft, the rotating arm, the experimental chamber (15), the counterweight chamber (16), and the hydraulic cylinder (14).

4. The single-axis centrifuge experimental device with floating support reaction force and shaft center trajectory measurement function according to claim 3, characterized in that: A coaxial positioning connector (23) is provided between the upper mounting plate where the detection mechanism (17) is located and the lower mounting plate where the fixed support assembly is located. The coaxial positioning connector (23) is arranged around the main shaft (7) and is used to maintain the coaxial installation reference of the floating support and the fixed support.

5. The single-axis centrifuge experimental device with floating support reaction force and shaft center trajectory measurement function according to claim 1, characterized in that: The four S-type tension and compression sensors (9) are respectively arranged in the positive first direction, negative first direction, positive second direction and negative second direction of the floating bearing seat (8). The rotation center of the fisheye bearing (21) intersects with the force axis of the corresponding S-type tension and compression sensor (9) to reduce the additional bending moment caused by installation deviation.

6. The single-axis centrifuge experimental device with floating support reaction force and shaft center trajectory measurement function according to claim 1, characterized in that: The two eddy current displacement sensors (10) are respectively set at a preset installation angle relative to the first direction and the second direction, and a probe bracket is provided between the two eddy current displacement sensors (10) and the mounting plate (18) to adjust the gap between the probe and the measuring surface of the main shaft (7).

7. The single-axis centrifuge experimental device with floating support reaction force and shaft center trajectory measurement function according to claim 1, characterized in that: A photoelectric sensor (11) is provided around the main shaft (7). A photoelectric sensor groove plate (24) is provided on the main shaft (7) or a component that rotates synchronously with the main shaft (7). The photoelectric sensor (11) and the photoelectric sensor groove plate (24) cooperate to generate at least one key phase pulse per revolution.

8. The single-axis centrifuge experimental device with floating support reaction force and shaft center trajectory measurement function according to claim 1, characterized in that: The rotating arm is equipped with hydraulic cylinders (14) located on both sides of the main shaft (7). Each hydraulic cylinder (14) includes a hydraulic oil chamber, a gas back pressure chamber, and a piston that separates the two chambers. The volume difference of the hydraulic oil chambers of the two hydraulic cylinders (14) is used to form an adjustable liquid mass difference. The experimental chamber (15), the counterweight chamber (16), and the hydraulic cylinders (14) are all fixed to the rotating arm by an anti-loosening connection structure. The frame is equipped with a protective structure covering the rotating area of ​​the rotating arm. An electro-hydraulic slip ring (12) is coaxially arranged on the outside of the main shaft (7). The electro-hydraulic slip ring (12) includes a hydraulic oil supply channel, a hydraulic oil return channel, and an electrical signal channel. The hydraulic oil supply channel and the hydraulic oil return channel connect the fixed end hydraulic source and the rotating end hydraulic cylinder (14). The electrical signal channel is used to transmit pressure, displacement, or status signals.

9. The single-axis centrifuge experimental device with floating support reaction force and shaft center trajectory measurement function according to claim 1, characterized in that: A mechanical limiting structure is provided between the mounting plate (18) and the floating bearing seat (8) to limit the maximum lateral displacement of the floating bearing seat (8). The limiting gap of the mechanical limiting structure is greater than the floating displacement under normal measurement conditions and less than the displacement corresponding to the contact between the eddy current displacement sensor (10) and the spindle (7).

10. The single-axis centrifuge experimental device with floating support reaction force and shaft center trajectory measurement function according to claim 1, characterized in that: It also includes a synchronous acquisition mechanism, which is electrically connected to four S-shaped tension and compression sensors (9), two eddy current displacement sensors (10), a photoelectric sensor (11), and a torque sensor (4), respectively.

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