Superspeed motorized spindle performance testing device

Abstract

The invention belongs to the technical field of mechanical equipment, and relates to an ultra-high-speed motorized spindle performance testing device, which mainly structurally comprises an operation table, a three-axis displacement table, a motorized spindle, an impeller cover connected with the three-axis displacement table through an axial pressure sensor, and an impeller connected with the motorized spindle, height-adjustable ground feet are arranged at the bottom of the operation table, a pressure-torsion composite sensor is arranged at the end of the impeller cover, a baffle is arranged on the inner wall of the impeller cover, the motorized spindle is arranged on the operation table through an upper sliding rail, the impeller extends into the impeller cover, and the impeller of the automobile turbocharger is coupled to the superspeed motorized spindle. The resistance acting with air during rotation of the impeller is used as a loading load, the impeller is used for simulating a tool machining process, the load is changed by using the impeller cover, various machining working conditions of the ultra-high-speed motorized spindle are reproduced, and the problems of inaccurate data acquisition and overheating of the motorized spindle caused by other physical factors are reduced. The temperature rise and the torque of the motorized spindle supporting bearing are measured in real time.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical equipment, and in particular relates to an ultra-high-speed electric spindle performance testing device, which utilizes the resistance of impeller rotation and air action to radially load and axially load the electric spindle. Background Art

[0002] With the rapid development of high-speed machining technology, the speed of spindle bearings is constantly increasing. The electric spindle is a combination of a traditional mechanical spindle and a motor. It has irreplaceable advantages over the mechanical spindle and has been widely used in the field of ultra-precision machining. It has become the most suitable core functional component for high-performance CNC machine tools. Based on this, the machining performance of the machine tool is positively correlated with the performance of the electric spindle, and its accuracy directly affects the geometric accuracy, surface quality and other parameters of the workpiece. It is necessary to carry out research on the measurement index system and test methods of the electric spindle, especially the dynamic test of the electric spindle, to provide guidance for improving the motion accuracy of the electric spindle and designing high-performance electric spindles.

[0003] At present, traditional transmission loading is mostly used for dynamic loading tests of ultra-high-speed electric spindles. For example, Chinese Patent 202410208302.1 discloses an electric spindle dynamic loading test device using a cable drive mechanism, including a test bench base, a rope drive unit, a fixed pulley assembly, an exciter, a movable pulley assembly, a rope, a vertical beam, a long cross beam, a short cross beam, an inner angle iron, an electric spindle tooling assembly, a tension sensor, a loading unit assembly, a coupling, an outer angle iron, a torque sensor and a dynamometer assembly; the four parts of the test bench base are as follows: There is a vertical beam fixed at each corner, two long horizontal beams are connected in parallel to the top of the vertical beam, and two short horizontal beams are connected between the two long horizontal beams through the outer angle iron and the inner angle iron; the electric spindle fixture assembly is installed on the test bench base, which is used to completely fix the electric spindle to the test bench base; the loading unit assembly is installed at the center of the device through 8 ropes, and it is connected to the electric spindle installed on the electric spindle fixture assembly through the tool handle interface at the left end of the loading rod, and the right end of the loading rod is connected to the dynamometer assembly through a coupling; the dynamometer assembly is also fixed on the test bench The base is used for torque loading and speed measurement; the torque sensor is installed between the dynamometer assembly and the coupling to provide real-time feedback on the size of the loading torque; the vibrator is installed on the test bench base, located at the center of the upper surface of the test bench base, and is used to apply time-varying loads; the rope drive units are installed on the test bench base, a total of 8, symmetrically installed on the inner and outer sides of the vertical beam; among them, the 4 rope drive units on the inner side of the vertical beam are installed with fixed pulley assemblies, and the 4 rope drive units on the outer side of the vertical beam are installed with movable pulley assemblies; the starting ends of the 8 ropes are respectively connected to the 8 eye screws on the loading unit assembly, among which the 4 ropes above the loading unit assembly are respectively turned through the 4 movable pulleys fixed on the inner angle iron, and are connected to the guide rail supports on the 4 rope drive units on the inner side of the vertical beam after being connected to the fixed pulley assembly; the 4 ropes below the loading unit assembly are connected to the guide rail supports on the 4 rope drive units on the outer side of the vertical beam after being turned through the movable pulley assembly; each rope is connected with a tension sensor for measuring the tension applied to each rope. Chinese patent 201910186493.5 discloses a high-speed electric spindle dynamic loading vibration measuring device, wherein a mobile platform is installed on the left side of the test bench, a spindle fixture is installed on the mobile platform, a spindle to be measured is installed on the spindle fixture, two vibration acceleration sensors are installed at the front end bearing position of the spindle to be measured, the spindle to be measured is connected to the connecting shaft B through a broaching device, the connecting shaft B is connected to the coupling, the coupling is connected to the connecting shaft A, a speed plate is installed on the connecting shaft A, the right side of the connecting shaft A is connected to the magnetic powder brake in the tangential force mechanism, a radial force mechanism is installed inside the tangential force mechanism, and an axial force mechanism is installed on the right side of the tangential force mechanism.Chinese patent 201120286625.0 discloses a high-speed electric spindle dynamic loading device, including a supporting part and a loading part; the supporting part includes a spindle base, an axial loading bracket, a radial loading pad and a dynamometer base, wherein: the spindle base includes a spindle pad, an adjustment pad and a clamping mechanism; the loading part includes a radial loading mechanism, an axial loading mechanism, a torque loading mechanism, a loading rod and a bearing unit, wherein: the torque loading mechanism includes an electric dynamometer, a high-speed spring tube coupling and an inverter; the adjustment pad and the clamping mechanism are sequentially stacked on the spindle pad and fixedly connected by bolts, and the electric dynamometer Fixed on the dynamometer base, the output end of the electric dynamometer is connected to the right end of the loading rod through the high-speed spring tube coupling, the left end of the loading rod is connected to the right end of the high-speed electric spindle to be tested installed in the clamping mechanism, the rotation axis of the output shaft of the electric dynamometer, the high-speed spring tube coupling, the loading rod and the main shaft through hole of the clamping mechanism are on the same horizontal line, the bearing unit is sleeved on the loading rod, the radial loading mechanism installed on the radial loading pad is directly below the bearing unit for contact connection, one end of the axial loading mechanism is installed on the axial loading bracket, and the other end is in contact connection with the bearing unit, and the electric dynamometer and the inverter are connected by wires. A high-speed electric spindle dynamic stiffness test device disclosed in Chinese patent 200910191495.X includes a base, a loading system and an automatic control unit; the loading system includes an axial loading system, a radial loading system and a test rod fixedly arranged on the high-speed electric spindle; a radial rolling bearing is arranged on the outer circle of the test rod, and a plane rolling bearing is arranged on the loading end of the test rod; the axial loading system includes an axial loading rod and an axial loading drive system, the axial loading drive system includes an axial loading servo motor, an axial loading drive screw and an axial loading drive nut, the axial loading screw is matched with the power output shaft of the axial loading drive servo motor, the axial loading drive nut is screwed on the axial loading drive screw with thread matching, one end of the axial loading rod is opposite to the plane rolling bearing in the axial direction, and the other end is pressed against the axial loading drive through a pressure sensor I. The radial loading system comprises a radial loading rod and a radial loading driving system, the radial loading driving system comprises a radial loading servo motor, a radial loading driving screw and a radial loading driving nut, the radial driving loading screw is matched with the power output shaft of the radial loading driving servo motor, the radial loading driving nut is screwed on the radial loading driving screw with thread matching, one end of the radial loading rod is radially opposite to the outer ring of the radial rolling bearing, and the other end is pressed against the radial loading driving nut through the pressure sensor II; a displacement sensor I is arranged relative to the outer circle of the test rod, and a displacement sensor II is arranged relative to the loading end of the test rod, the signals collected by the pressure sensor I, the pressure sensor II, the displacement sensor I and the displacement sensor II are transmitted to the automatic control unit, and the command of the automatic control unit is output to the axial loading servo motor and the radial loading servo motor.It is not only difficult to ensure that the coaxiality between the parts meets the requirements when the electric spindle runs at ultra-high speed, but also it will generate huge inertia force, which will cause the electric spindle to not run smoothly. At the same time, the ultra-high-speed operation of each transmission part will generate a lot of heat due to friction, which will affect the measurement of dynamic parameters.

[0004] Therefore, an ultra-high-speed electric spindle performance testing device was developed and designed. The device uses non-contact dynamic loading to reproduce the stress state of the electric spindle bearings under actual working conditions and explore the impact of different working conditions on the dynamic performance of the electric spindle. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the prior art, develop and design an ultra-high-speed electric spindle performance testing device, and solve the problems of low coaxiality, poor stability and high heat generation in the loading mode of the traditional testing device.

[0006] The main structure of an ultra-high-speed electric spindle performance testing device according to the present invention is as follows Figure 1 As shown, it includes an operating table and a three-axis translation table and an electric spindle arranged thereon, as well as an impeller cover connected to the three-axis translation table through an axial pressure sensor, and an impeller connected to the electric spindle;

[0007] Among them, the bottom of the operating table is provided with height-adjustable feet;

[0008] A compression-torsion composite sensor is provided at the end of the impeller cover, and a baffle is provided on the inner wall;

[0009] The electric spindle is arranged on the operating table through an upper slide rail, and a temperature sensor is also arranged on the operating table;

[0010] The impeller extends into the impeller cover.

[0011] The axial pressure sensor 4 of the present invention comprises a spoke-type weighing sensor with an error of less than 0.1%, which is used to collect the pressure of the impeller cover. When the force of the impeller cover is transmitted to the axial pressure sensor, the force measuring element is affected by the external force, the strain gauge is deformed, and the deformation causes the resistance of the strain gauge to change. The magnitude of the applied axial force is determined by the change in resistance. At the same time, the magnitude of the axial force is also the magnitude of the axial force on the bearing of the electric spindle 7.

[0012] The impeller cover takes on the first line of protection during operation, and acts as the load measurement carrier together with the impeller. The impeller rotates to disturb the gas to generate airflow, which acts on the baffle to simulate the working condition of the tool during processing.

[0013] The compression-torsion composite sensor includes a multi-dimensional force composite sensor with multiple strain gauges built in. When the impeller cover has a tendency to move, the strain gauge undergoes a slight deformation, and the deformation generates an electrical signal, which is transmitted to an external device. After receiving the electrical signal, the external device processes the signal to obtain the load applied to the electric spindle and the radial load on the bearing of the electric spindle;

[0014] The electric spindle includes an ultra-high-speed electric spindle for various processing methods, and the bottom is assembled to the slide rail through a fixture so that the electric spindle 7 can move axially and adjust the position;

[0015] The impeller includes an intake impeller of an automobile turbocharger, which is made of nickel-aluminum alloy, is lightweight, and has a maximum speed of 120,000-160,000 rpm. It is assembled with the shaft head of the electric spindle through a tension sleeve. Its geometric characteristics enable the axial force and reverse torque generated by the impeller when it rotates to act on the shaft head of the electric spindle through the tension sleeve, which is used to simulate the working state of the tool during ultra-high-speed electric spindle processing;

[0016] The temperature sensor includes a PT100 temperature sensor, which can convert temperature changes into potential changes. One end is installed inside the electric spindle to measure the real-time temperature rise.

[0017] The working principle of the impeller cover and the impeller involved in the present invention is as follows Figure 2 As shown, the three-axis translation stage is adjusted to make the impeller cover coaxial with the impeller. The impeller rotates in the direction shown by w1, pushing the airflow to diffuse along the axial and radial directions of the impeller cover. The effect of the axial diffusion airflow acting on the inner wall of the impeller cover is equivalent to the axial force F a The radial diffuser airflow w2 acts on the baffle to produce radial and circumferential effects. The circumferential effect makes the impeller cover have a rotational tendency to generate torque. Since the impeller cover is coaxial with the impeller, the radial effect is 0 for the overall integral and does not produce a force effect. The integral of the radial airflow on the circumference is not 0, which produces a radial force effect along a specific direction. Based on this, loading and measurement are achieved in a non-contact manner.

[0018] Among them, the torque can be adjusted by changing the length, angle or size of the baffle;

[0019] Changing the distance between the impeller and the inner end surface of the impeller cover can adjust the axial force;

[0020] By changing the relative position of the impeller and the impeller cover in the Y-axis direction, the radial force can be adjusted.

[0021] An ultra-high-speed electric spindle performance testing device involved in the present invention clamps an impeller at the position where the tool is installed on the electric spindle. The resistance generated by the rotation of the impeller is used to simulate the radial force and axial force exerted on the tool during operation, reproduce the stress state of the electric spindle bearings under actual working conditions, and explore the influence of different working conditions on the dynamic performance of the electric spindle.

[0022] Compared with the prior art, the present invention couples the automobile turbocharger impeller to the ultra-high-speed electric spindle, takes the resistance of the impeller rotating with the air as the loading load, accurately loads through a three-axis coordinate table, adopts an impeller to simulate the tool processing process, uses an impeller cover to change the load, reproduces various processing conditions of the ultra-high-speed electric spindle, realizes non-contact loading through gas transmission, reduces the problems of inaccurate data collection and overheating of the electric spindle caused by other physical factors, and measures the temperature rise and torque of the electric spindle support bearing in real time through an axial pressure sensor, a compression-torsion composite sensor and a PT100 temperature sensor; the present invention has a simple structure, uses the resistance of the impeller rotation and the air to radially and axially load the electric spindle, is suitable for various ultra-high-speed electric spindles, does not affect the collection of basic parameters of the electric spindle, and the measurement results are used to evaluate the overall service performance of the electric spindle, which is of great significance for the technical development of ultra-high-speed electric spindles and practical engineering applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the main structural principle of the present invention.

[0024] Figure 2 The present invention is a schematic diagram of the working principle of the impeller cover and the impeller.

[0025] Figure 3 This is a schematic diagram of axial force control involved in the present invention.

[0026] Figure 4 This is a schematic diagram of radial force control involved in the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.

[0028] Embodiment 1:

[0029] The main structure of an ultra-high-speed electric spindle performance testing device involved in this embodiment is as follows Figure 1 As shown, it includes an operating table 1, a three-axis displacement table 2, a slide rail 3, an axial pressure sensor 4, an impeller cover 5, a compression-torsion composite sensor 6, an electric spindle 7, an impeller 8, a foot 9, a baffle 10 and a temperature sensor 11; the three-axis displacement table 2 and the slide rail 3 are arranged on the operating table 1, the axial pressure sensor 4 is arranged on the three-axis displacement table 2, the axial pressure sensor 4 is connected to the impeller cover 5, the end of the impeller cover 5 is arranged with a compression-torsion composite sensor 6, the slide rail 3 is arranged with an electric spindle 7, the electric spindle 7 is connected to the impeller 8, and the impeller 8 extends into the internal cavity of the impeller cover 5; in addition, a foot 9 with adjustable height is arranged at the bottom of the operating table 1, a plurality of detachable baffles 10 are arranged at equal intervals on the inner wall of the impeller cover 5, and a temperature sensor 11 is also arranged on the electric spindle 7.

[0030] The operating table 1 involved in this embodiment can provide sufficient rigidity and assembly accuracy;

[0031] The three-axis translation table 2 is an XYZ three-axis translation table, which is installed on the operating table 1 and drives the impeller cover 5 to move accurately; the transmission mechanism includes guide rail guide devices and corresponding driving devices for the three axes, and the guide rail guide device of each axis is composed of a guide rail and a slider, and the slider is connected to the guide rail through a rolling bearing and performs translational motion on the corresponding axis. The slider is provided with a driving device, and the driving device drives the slider to move back and forth on the corresponding axis with an accuracy of 0.02mm. Among them, the X-axis translation table and the Z-axis translation table are used to adjust the coaxiality of the impeller cover 5 to ensure that the impeller cover 5 is only subjected to axial pressure and torque after the impeller 8 is running, and the Y-axis translation table is used to adjust the eccentricity of the impeller 8 and the impeller cover 5, and apply radial load to the bearing of the electric spindle 7;

[0032] The axial pressure sensor 4 is fixed to the three-axis translation platform 2 by bolts to measure the axial load in real time;

[0033] The compression-torsion composite sensor 6 is located behind the axial pressure sensor 4 and is connected to the impeller cover 5 to convert loads and measure torque and radial force;

[0034] The electric spindle 7 is installed in the slide rail 3 on the operating table 1 through a fixture 12, so as to adjust the position of the electric spindle 7 and be compatible with different electric spindles 7 for testing;

[0035] The impeller 8 is connected to the shaft head of the electric spindle 7 through a tightening sleeve to simulate a machining tool;

[0036] The temperature sensor 11 is installed in the bearing chamber of the electric spindle 7 to monitor the temperature of the outer ring of the bearing in real time.

[0037] The specific process of using the ultra-high-speed electric spindle performance testing device involved in this embodiment includes the following steps:

[0038] S1. Preparation

[0039] First, supply oil continuously to the bearings of the electric spindle 7 for half an hour to discharge impurities in the bearings and perform preliminary lubrication on the bearings;

[0040] Then, the electric spindle 7 is run for half an hour under no-load and low-speed conditions respectively to fully lubricate the bearings;

[0041] Finally, the three-axis translation stage 2 is adjusted to achieve the target load;

[0042] S2. Collect data

[0043] The electric spindle 7 is turned on, and the impeller 8 rotates to generate airflow. The baffle 10 is impacted by the airflow to generate a relative motion trend. The baffle 10 converts the impact of the rotating airflow along the axial direction into an axial force. The magnitude of the axial force is measured by the axial pressure sensor 4, and the magnitude of the motion trend is measured by the compression-torsion composite sensor 6. The temperature sensor 11 senses the change in temperature, and the resistance value changes linearly with the temperature change. The temperature of the electric spindle 7 is measured in real time, and the temperature change of the electric spindle 7 is recorded;

[0044] During this process, the temperature output value of the temperature sensor 11 is fed back to the control system of the electric spindle 7. When it reaches an abnormal value, an early warning is issued and the machine is immediately shut down for maintenance;

[0045] S3. Analyze data

[0046] The bearing temperature rise and rolling torque data of the electric spindle 7 are graphically analyzed, and the relationship curve between the oil supply parameters, operating parameters and measured data is established. The change law and internal mechanism are analyzed, the parameters are optimized, and the service performance of the electric spindle 7 is evaluated.

Claims

1. An ultra-high-speed electric spindle performance testing device, characterized in that: The main structure includes an operating table and a three-axis translation platform and an electric spindle arranged thereon, as well as an impeller cover connected to the three-axis translation platform through an axial pressure sensor, and an impeller connected to the electric spindle; a compression-torsion composite sensor is arranged at the end of the impeller cover, a baffle is arranged on the inner wall, and the impeller extends into the impeller cover.

2. The ultra-high-speed electric spindle performance testing device according to claim 1, characterized in that: The axial pressure sensor includes a spoke-type weighing sensor, which collects the pressure of the impeller cover. When the force of the impeller cover is transmitted to the axial pressure sensor, the force measuring element is affected by the external force, and the strain gauge is deformed. The deformation causes the resistance of the strain gauge to change. The magnitude of the applied axial force is determined by the change in resistance. At the same time, the magnitude of the axial force is also the magnitude of the axial force on the bearing of the electric spindle.

3. The ultra-high-speed electric spindle performance testing device according to claim 2, characterized in that: The impeller cover takes on the first line of protection during operation, and acts together with the impeller as the load measurement carrier. The impeller rotates to disturb the gas to generate airflow, which acts on the baffle to simulate the working condition of the tool during machining.

4. The ultra-high-speed electric spindle performance testing device according to claim 3, characterized in that: The compression-torsion composite sensor includes a multi-dimensional force composite sensor with multiple strain gauges built in. When the impeller cover generates a movement tendency, the strain gauge undergoes a slight deformation, and the deformation generates an electrical signal, which is transmitted to an external device. After the external device receives the electrical signal, it processes the signal to obtain the load applied to the electric spindle 7 and the radial load on the bearings of the electric spindle.

5. The ultra-high-speed electric spindle performance testing device according to claim 4, characterized in that: The electric spindle comprises an ultra-high-speed electric spindle, the bottom of which is assembled on the slide rail through a clamp.

6. The ultra-high-speed electric spindle performance testing device according to claim 5, characterized in that: The impeller includes the intake end impeller of the automobile turbocharger, which is made of nickel-aluminum alloy, is lightweight, and has a maximum speed of 120,000-160,000 rpm. It is assembled with the shaft head of the electric spindle through a tension sleeve. When the impeller rotates, the axial force and reverse torque generated by pushing the air act on the shaft head of the electric spindle through the tension sleeve, simulating the working state of the tool during ultra-high-speed electric spindle processing.

7. The ultra-high-speed electric spindle performance testing device according to any one of claims 1 to 6, characterized in that: The bottom of the operating table is provided with a foot with adjustable height; the electric spindle is arranged on the operating table through an upper slide rail, and a temperature sensor is also arranged on the upper slide rail.

8. The ultra-high-speed electric spindle performance testing device according to claim 7, characterized in that: The temperature sensor comprises a PT100 temperature sensor, one end of which is installed inside the electric spindle.

9. The ultra-high-speed electric spindle performance testing device according to claim 7, characterized in that: The impeller is clamped at the position where the tool is installed on the electric spindle. The resistance generated by the rotation of the impeller simulates the radial force and axial force that the tool is subjected to during operation, and reproduces the stress state of the electric spindle bearing under actual working conditions. The working principle of the impeller cover and the impeller is: adjust the three-axis translation table to make the impeller cover coaxial with the impeller. The impeller rotates to push the airflow to diffuse axially and radially along the impeller cover. The effect of the axially diffused airflow on the inner wall of the impeller cover is equivalent to the axial force. The radially diffused airflow acts on the baffle to produce radial and circumferential effects. The circumferential effect makes the impeller cover have a rotation tendency to generate torque. Since the impeller cover is coaxial with the impeller, the radial effect is integrated to 0 for the whole, and no force effect is generated. The integral of the effect of the radial airflow on the circumference is not 0, which produces a radial force effect along a specific direction.

10. The ultra-high-speed electric spindle performance testing device according to claim 9, characterized in that: The torque can be adjusted by changing the length, angle or size of the baffle; the axial force can be adjusted by changing the distance between the impeller and the inner end face of the impeller cover; the radial force can be adjusted by changing the relative position of the impeller and the impeller cover in the Y-axis direction.

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