Electricity auxiliary turbocharger rotor experiment table and application

Abstract

The application discloses an electric auxiliary turbocharger rotor experiment table and application, and through an axial locking nut, a thrust bearing and a floating ring bearing supporting a shafting structure, equivalent compressor blades and a turbine disc simulation mass, a middle motor structure driving, the application can realize an electric auxiliary turbocharger static contact parameter identification experiment, a dynamics characteristic and a parameter matching relationship experiment. The application fixes the shafting components through an axial locking device, adjusts the tightening torque size and the tightening step length, changes the pre-tightening parameters in the form, combines metal processing process parameters, realizes the identification of the static contact parameters. The cooperation form and the cooperation parameters of the middle motor and the rotating shaft are changed, the dynamics characteristic and the parameter matching relationship experiment can be realized; equivalent simulation counterweight discs are arranged on the central rotating shaft, the weight and the number of the counterweight bolts are adjusted, and the unbalance of the rotor and typical assembly fault experiments are simulated.

Description

Technical Field

[0001] This invention relates to the technical field of turbocharger test benches, and particularly to a novel electrically assisted turbocharger rotor test bench and its application that takes into account the connection structure and assembly process. Background Technology

[0002] With the development of the automotive industry and internal combustion engines, exhaust gas turbocharging technology has been widely used in engine design due to its advantages in fuel economy, environmental protection of exhaust emissions, and improved engine performance. However, due to the influence of variable load environments, harsh working environments, and significant hysteresis effects, turbocharger rotor systems are prone to fatigue failure and overspeed damage. To solve the engineering problems of traditional turbochargers, high-speed electric motor-assisted turbocharger design has emerged. The design of new electric-assisted turbochargers needs to consider more complex shaft assembly structures and assembly process errors, which can lead to prominent overall vibration problems and vibration damage of some components. The introduction and assembly of the electric motor will change the initial structure of the rotor system, thus making the structural vibration response uncertain; and as vibration problems become more prominent, the contact state between the shaft mating parts during machining and assembly will also change. This contact nonlinearity will have a significant impact on the vibration characteristics of the rotor system, and the parameter uncertainties brought about by the connection structure will also pose challenges to the turbocharger structural dynamics design. The overall vibration characteristics are highly dependent on the variation of axial preload assembly parameters, the influence of shaft component assembly processes, and stability effects.

[0003] However, existing experimental platforms have the following problems:

[0004] 1. Existing experimental platforms typically simplify shaft components significantly, ignoring the fit and parameters between sleeves and shafts, motors and shafts, or integrating shaft components into a central shaft after simply equipping them with equivalent mass and moment of inertia.

[0005] 2. Because traditional test benches adopt an integrated design approach and lack precision test bench manufacturing methods, the contact effect between axial components is completely ignored. As a result, existing test benches cannot conduct experimental research and testing on the contact characteristics of rotor test benches under different working conditions.

[0006] 3. In the electric-assisted turbocharger test bench, the drive method is usually an external motor connected to the central rotating shaft through a coupling. The original high-speed motor is simplified into an equivalent disk through the rotating shaft design. This structure ignores the influence of the coupling between the motor and the rotor system, and the impact of the assembly problem between the motor and the rotor system on the system performance is also ignored.

[0007] 4. Preload has a significant impact on system performance. Preload and assembly clearance are affected by factors such as the step length and number of steps during bolt tightening, as well as the rotational speed of the shaft. Under different operating conditions, such as stationary, low-speed, or high-speed operation, they exhibit complex evolution trends. In particular, under conditions where high-speed shaft rotation causes excessive vibration, it is necessary to analyze the relationship between parameters such as bolt preload magnitude, number of tightening steps, tightening step length, axial structural clearance, and rotor amplitude deviation. Existing experimental platforms cannot meet these requirements. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and solve the problem that the existing test benches are difficult to consider the changes in component contact effects and the influence of assembly process factors under high speed or operating speed margin. The invention provides an electric-assisted turbocharger rotor test bench and its application, which is mainly used to identify static contact parameters and conduct dynamic characteristic experiments on complex combined rotor shaft systems under typical rotor faults and assembly problems.

[0009] This experimental platform integrates existing precision machining processes, decomposing the traditional one-piece machining process of rotor experimental platforms into different shaft system components. Considering the contact forms and parameters between different shaft system components, the initial static displacement of the rotor experimental platform is controlled, thereby effectively identifying the static parameters of the rotor structure considering contact effects. Simultaneously, the bearing housing is machined separately to facilitate the introduction of a mid-mounted motor in the electric-assisted turbocharger. Considering the influence of the separate bearing and mid-mounted motor assembly, the dynamic characteristics of the rotor system are effectively measured. The physical parameters of the compressor impeller and turbine disk are equivalentized to simplify complex curved blade profiles. Furthermore, the additional counterweight bolts on the counterweight plate can be repeatedly disassembled and reassembled to simulate impeller and rotor imbalance faults. By comprehensively considering the effects of connection contact effects and assembly processes, the novel structural design of the traditional electric-assisted turbocharger rotor experimental platform achieves a multi-factor, multi-functional coupled novel rotor experimental platform design.

[0010] The objective of this invention is achieved through the following technical solution:

[0011] An electric-assisted turbocharger rotor test bench, taking into account the influence of axial connection structure and assembly process factors, includes a support. A first bearing seat and a second bearing seat are separately fixed on the left and right sides of the support. A compressor wheel seat and a turbine seat are respectively fixed on the outer sides of the first bearing seat and the second bearing seat. A compressor impeller and a turbine disk are respectively installed in the compressor wheel seat and the turbine seat. A floating ring bearing, a thrust limit bearing and an elastic sealing ring are provided in both the first bearing seat and the second bearing seat to support the central rotating shaft.

[0012] Both ends of the central rotating shaft are fastened with lock nuts. The outer end caps are installed on the outer sides of the compressor wheel seat and the turbine seat. The central rotating shaft located between the first bearing seat and the second bearing seat is connected to the shaft sleeve and the motor rotor with clearance fit.

[0013] Both the compressor wheel seat and the turbine seat are provided with pipeline interfaces and guide channels, through which oil film is filled into the floating ring bearing and the thrust limit bearing; both the compressor wheel seat and the turbine seat are provided with mounting holes for installing eddy current sensors.

[0014] Several non-contact displacement sensors are also provided on one side of the central shaft located between the first bearing housing and the second bearing housing, for measuring the lateral vibration of the central shaft as a whole.

[0015] Furthermore, the front part of the central shaft is connected to the first bearing housing via a shaft sleeve, and the rear part of the central shaft is directly connected to the second bearing housing; different support forms affect the concentricity and initial static displacement of the central shaft, shaft sleeve, and motor rotor.

[0016] Furthermore, the support is provided with a reference groove, which is used to align the centerline of the compressor wheel seat and the turbine seat with the reference groove during installation to ensure structural alignment.

[0017] Furthermore, by changing the tightening torque of the lock nut with a torque wrench, the magnitude and preload of the axial preload can be directly altered, thereby changing the shaft connection stiffness of the central rotating shaft.

[0018] Furthermore, elastic sealing rings are provided between the central shaft and the compressor wheel seat and the turbine seat, with two elastic sealing rings respectively installed on the central shaft and the turbine seat.

[0019] Furthermore, the central shaft is rotatably connected to both the first and second bearing seats via floating ring bearings; the opposite sides of the first and second bearing seats are each fitted with an inner end cap by several fixing bolts; the preload of the fixing bolts and locking nuts can affect the axial tilt of the central shaft and affect whether the central shaft will bulge.

[0020] Furthermore, the compressor impeller disk and turbine disk are used to simulate the counterweight disk, and the unbalanced state of the central shaft is simulated by adjusting the weight and number of fixing bolts.

[0021] This invention also provides an application of an electric-assisted turbocharger rotor test bench. By applying different torques to the locking nut using a torque wrench, the magnitude of the axial preload is changed. While using the thrust limit bearing to fix the axial displacement, the axial preload is transmitted to press the shaft system components together. The compressor impeller and turbine disk are machined with graduations to obtain static contact deformation. By using the relationship between the metal parts machining process parameters, a structural static contact parameter identification experiment is performed. The shaft system components include a shaft sleeve and a motor rotor.

[0022] This invention also provides an application of an electric-assisted turbocharger rotor test bench, which processes several motor rotors with different inner diameters and controls the fit parameters with the central shaft through different fit forms and small clearance fit amounts. Through displacement sensors and eddy current sensors, it realizes the characteristic experiments of compressor impeller and turbine disk rotation at different speeds.

[0023] This invention also provides an application of an electric-assisted turbocharger rotor test bench, which constructs an unbalanced mass of the central shaft by adjusting the weight and number of counterweight bolts on the counterweight plate; and conducts experiments on impeller dynamic characteristics, motor rotor amplitude and shaft center trajectory at different speeds to simulate classic fault and assembly problem experiments.

[0024] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0025] 1. High-precision fit control and vibration characteristic research: This invention controls the fit clearance of the motor shaft using precision machining technology, enabling experimental research on the impact of various radial fit types and fit parameters on the structural vibration characteristics. Through meticulous consideration of complex shaft structures, the response accuracy and experimental efficiency of contact effects on the dynamic characteristics of the rotor system are significantly improved.

[0026] 2. Analysis of the Influence of Assembly Process on Vibration Characteristics: This invention utilizes a shaft-end locking nut and a separately machined bearing housing. By adjusting parameters such as the preload, number of tightening steps, and step length of the fixing bolts connected to the support, the influence of these process variables on the static characteristics (e.g., axis alignment and shaft deflection) and dynamic characteristics (e.g., turntable and motor vibration amplitude and shaft trajectory) of the central shaft. This provides experimental evidence for revealing the influence of assembly process factors on the vibration characteristics of the rotor system.

[0027] 3. Imbalance Simulation and Fault Experiment Function: The counterweight plate on the central shaft can simulate the imbalance state of the shaft by adjusting the number and weight of the counterweight bolts. This experimental platform can simulate dynamic characteristics such as impeller dynamic characteristics, motor amplitude, and shaft trajectory at different speeds, effectively reproducing and studying the impact of assembly processes and typical faults on system performance, and further promoting fault diagnosis and optimization design of the turbocharger rotor system.

[0028] 4. Static Parameter Identification of Contact Effect: By independently designing the shaft sleeve and floating ring bearing fit on the experimental platform, the static contact parameters in complex combined rotor shaft systems were accurately identified. The influence of variables such as contact nonlinearity and assembly clearance on static characteristics was comprehensively analyzed, which helps to optimize the structural design and process adjustment of electrically assisted turbochargers.

[0029] 5. Multi-factor coupling research platform: By introducing a split bearing housing and a centrally located motor assembly form, and by equivalencing the physical parameters of the compressor impeller and turbine disk, this invention successfully realizes the multi-functional integration and multi-factor coupling research of a novel experimental platform, providing a reliable experimental platform for analyzing complex contact and assembly effects under high speed margin.

[0030] 6. Precise Measurement of Dynamic Characteristics: The experimental platform of this invention is equipped with multiple non-contact displacement sensors and eddy current sensors, which can accurately measure the lateral vibration and dynamic response of the central shaft. Combined with different assembly methods and operating conditions, it further improves the measurement and experimental analysis capabilities of the turbocharger rotor system's dynamic characteristics. Attached Figure Description

[0031] Figure 1 This is a schematic side view of the overall structure of the rotor test bench of the present invention.

[0032] Figure 2 for Figure 1 A cross-sectional view along the BB direction in the middle.

[0033] Figure 3 This is an axial cross-sectional view of the sealing structure.

[0034] Figure 4 This is a schematic diagram of a single, separately machined bearing housing.

[0035] Figure 5 This is a front cross-sectional view of a single, separately machined bearing housing.

[0036] Figure 6 A top-view cross-sectional view of a single, separately machined bearing housing.

[0037] Figure 7 This is a cross-sectional view of the shaft sleeve.

[0038] Reference numerals: 1. Support; 2. Compressor impeller seat; 3. Locking nut; 4. Compressor impeller; 5. Elastic sealing ring; 6. Thrust limit bearing; 7. Floating ring bearing; 8. Turbine seat; 9. Turbine disk; 10. Central shaft; 11. Pipeline interface; 12. Motor rotor; 13. Shaft sleeve; 14. Inner end cover; 15. First bearing seat; 16. Turbine; 17. Outer end cover; 18. Second bearing seat Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0040] like Figure 1 and Figure 2 As shown, this embodiment provides an electric-assisted turbocharger rotor test bench, incorporating the influence of axial connection structure and assembly process factors. The test bench includes a support 1, with a first bearing housing 15 and a second bearing housing 18 separately fixed on the left and right sides of the support 1. A compressor impeller 2 and a turbine housing 8 are respectively fixed to the outer sides of the first bearing housing 15 and the second bearing housing 18. To avoid air turbulence, a compressor impeller 4 and a turbine disk 9 are respectively installed inside the compressor impeller housing and the turbine housing, and are connected to the first and second bearing housings as a whole by fixing bolts. The separate installation is used to simulate the flow guide volute system where the compressor impeller 4 and the turbine disk 9 are located. Both the first bearing housing 15 and the second bearing housing 18 are equipped with a floating ring bearing 7, a thrust limiting bearing 6, and an elastic sealing ring 5 to support the central rotating shaft 10. A centrally located motor is coupled to the rotor system to simulate the electric auxiliary characteristics under high-speed motor conditions.

[0041] Both ends of the central rotating shaft 10 are fastened by locking nuts 3. The outer end caps 17 are installed on the outer sides of the compressor wheel seat 2 and the turbine seat 8. The central rotating shaft 10 located between the first bearing seat 15 and the second bearing seat 18 is connected to the shaft sleeve 13 and the motor rotor 12 with clearance fit.

[0042] Both the compressor wheel mount 2 and the turbine mount 8 are equipped with pipe interfaces 11 and guide channels, through which oil film is filled into the floating ring bearing 7 and the thrust limit bearing 6. Both the compressor wheel mount 2 and the turbine mount 8 are equipped with mounting holes for installing eddy current sensors. The eddy current sensors are mounted on magnetic bases and fixed to the supports by magnetic bases. The probes extend into the mounting holes for non-contact measurement.

[0043] Several non-contact displacement sensors are also provided on one side of the central rotating shaft 10 located between the first bearing housing 15 and the second bearing housing 18, for measuring the overall lateral vibration of the central rotating shaft. The displacement sensors are fixed on the support and connected to the preamplifier, with the probe close to the central rotating shaft for non-contact measurement.

[0044] Specifically, in compressor impeller housing 2, the counterweight disc simulating the compressor impeller 4 is axially pre-tightened by a locking nut 3 via a threaded connection locking device. The right side is restricted by a thrust limit bearing 6, limiting the overall axial displacement and transmitting axial force to the shaft sleeve structure connected to the floating ring bearing 7. The motor rotor 12 structure is pre-loaded onto the right side of the central shaft. This combined shaft structure takes into account the contact effects between components and the variations in contact effects under high-speed conditions and within the operating speed margin range. Turbine housing 8 is similarly restricted by a simulated turbine counterweight disc via a locking nut and a thrust bearing. The pipe interfaces 11 and guide channels on the left and right bearing housings allow lubricating oil to be introduced via an oil pump during operation, providing a suitable working environment for the floating ring bearing.

[0045] Preferably, the front part of the central shaft 10 is connected to the first bearing seat 15 through the shaft sleeve 13, and the rear part of the central shaft 10 is directly connected to the second bearing seat 18; different support forms affect the concentricity and initial static displacement of the central shaft 10, the shaft sleeve 13 and the motor rotor 12.

[0046] Preferably, the support 1 is provided with a reference groove, which is used to align the centerline of the compressor wheel seat 2 and the turbine seat 8 with the reference groove during installation to ensure structural alignment.

[0047] Preferably, by changing the tightening torque of the locking nut 3 with a torque wrench, the magnitude and preload of the axial preload are directly changed, thereby altering the shaft connection stiffness of the central rotating shaft 10.

[0048] Preferably, elastic sealing rings are provided between the central rotating shaft and the compressor wheel seat and the turbine seat, with two elastic sealing rings respectively provided on the central rotating shaft and the turbine seat; the central rotating shaft is rotatably connected to the first bearing seat and the second bearing seat via floating ring bearings; an inner end cover 14 is installed on the opposite side of the first bearing seat and the second bearing seat via several fixing bolts; the preload of the fixing bolts and the locking nut 3 can affect the axial tilt of the central rotating shaft and affect whether the central rotating shaft will bulge; a counterweight plate is also provided on the central rotating shaft 10, and several counterweight bolts are detachably connected to the counterweight plate. By adjusting the weight and number of counterweight bolts, the unbalanced state of the central rotating shaft can be simulated.

[0049] See Figure 1 This exhibit showcases the axial assembly details of the compressor wheel housing and turbine housing, as well as the radial fit details of the shaft system components. The split bearing housing is connected to the support 1 via fixing bolts, and axially connected to the turbine housing via hexagonal bolts. The outer side of the central rotating shaft 10 is fitted with a clearance-fit sleeve structure and a motor rotor structure.

[0050] Figure 3The sealing structure, consisting of an elastic sealing ring 5 and a sealing end cap, is shown, which provides appropriate oil pressure and oil sealing performance for the operation of the thrust limit bearing and the floating ring bearing.

[0051] Figure 4 The image shows a front view of a single, split-type bearing housing. Multiple flow ports in different directions are provided on the bearing housing and bearing end cap, which can be connected to pipeline interfaces to provide an oil circuit environment. Additionally, sensors can be inserted after drilling to measure oil film pressure, temperature, and lubrication parameters.

[0052] Figure 5 The diagram shows a cross-sectional view of the bearing housing, which provides space for the oil passage through the guide port and drainage channel, and communicates with the floating ring bearing and thrust limit bearing to provide a suitable working environment. At the same time, the external sealing structure prevents the leakage of lubricating oil.

[0053] Figure 6 The diagram shows a cross-sectional view of the bearing housing from a top view, demonstrating the connection between the bearing housing and the turbine housing, which is fixed by long bolts. It also shows the structure of the elastic sealing ring.

[0054] Figure 7 A cross-sectional view of the entire shaft sleeve 13 is shown. The left end has a small-scale concave shape because it needs to be connected to the inner end cap 14 on the floating ring bearing 7 and the first bearing seat 15; the right end is pressed into contact with the motor rotor.

[0055] Specifically, the following experimental methods can be achieved using the aforementioned electrically assisted turbocharger rotor test bench:

[0056] 1. Static structure and parameter identification experiment:

[0057] (1) Experiment on axial preload and contact parameter identification:

[0058] By applying different torques to the shaft end lock nut with a torque wrench, the magnitude of the axial preload is changed. The axial displacement is fixed by the thrust limit bearing while transmitting the axial preload, thus pressing the high-speed motor and rotor system together. Three-phase sensors perpendicular to each other are placed in the middle section to measure motor vibration. Eddy current sensors are inserted through holes drilled in the left and right end covers to realize the compressor impeller and turbine disc motion characteristics experiment at different speeds.

[0059] (2) Experiment on motor matching form and matching parameters:

[0060] Multiple motor stators with different inner diameters are machined and their fit parameters are adjusted by controlling different fit forms and small clearance fit amounts with the central shaft. Three-phase sensors perpendicular to each other are placed in the middle section to measure motor vibration. Eddy current sensors are inserted through holes drilled in the left and right end covers to conduct experiments on the rotor and turbine disk characteristics of the compressor at different speeds.

[0061] 2. Fault Experiment:

[0062] (1) Experiment on the misalignment of the bearing housing bore in a split-type machining process:

[0063] Adjusting the thickness of the shims added under the base creates a misalignment condition between the central shaft, left base, and right base; experiments can be conducted on the impeller dynamic characteristics, motor rotor amplitude, and shaft trajectory at different speeds.

[0064] (2) Experiment on the imbalance between the front and rear impellers:

[0065] By adjusting the weight and number of counterweight bolts on the counterweight plate, an unbalanced mass can be constructed on the central rotating shaft; experiments can be conducted on the impeller dynamic characteristics, motor rotor amplitude, and shaft center trajectory at different speeds.

[0066] This invention is not limited to the embodiments described above. The above description of specific embodiments is intended to illustrate and explain the technical solutions of this invention. The specific embodiments described above are merely illustrative and not restrictive. Without departing from the spirit and scope of the claims, those skilled in the art can make many specific modifications based on the teachings of this invention, and these modifications all fall within the scope of protection of this invention.

Claims

1. An experimental rig for an electrically assisted turbocharger rotor, characterized in that, Introducing the influence of axial connection structure and assembly process factors, including the support, the support has a first bearing seat and a second bearing seat fixed separately on the left and right sides, the compressor wheel seat and turbine seat are fixed on the outer sides of the first bearing seat and the second bearing seat respectively, the compressor impeller and turbine disk are installed in the compressor wheel seat and the turbine seat respectively, and the first bearing seat and the second bearing seat are provided with floating ring bearings, thrust limit bearings and elastic sealing rings to support the central rotating shaft; Both ends of the central rotating shaft are fastened with lock nuts. The outer end caps are installed on the outer sides of the compressor wheel seat and the turbine seat. The central rotating shaft located between the first bearing seat and the second bearing seat is connected to the shaft sleeve and the motor rotor with clearance fit. Both the compressor wheel seat and the turbine seat are provided with pipeline interfaces and guide channels, through which oil film is filled into the floating ring bearing and the thrust limit bearing; both the compressor wheel seat and the turbine seat are provided with mounting holes for installing eddy current sensors. Several non-contact displacement sensors are also provided on one side of the central shaft located between the first bearing housing and the second bearing housing, for measuring the lateral vibration of the central shaft as a whole. The front part of the central shaft is connected to the first bearing housing through the shaft sleeve, and the rear part of the central shaft is directly connected to the second bearing housing; different support forms affect the concentricity and initial static displacement of the central shaft, shaft sleeve and motor rotor. The support is provided with a reference groove, which is used to align the centerline of the compressor wheel seat and the turbine seat with the reference groove during installation to ensure structural alignment. By changing the tightening torque of the lock nut with a torque wrench, the magnitude and preload of the axial preload can be directly changed, thereby altering the shaft connection stiffness of the central rotating shaft. The central shaft is rotatably connected to both the first and second bearing seats via floating ring bearings; the inner end caps are installed on the opposite sides of both the first and second bearing seats via several fixing bolts; the preload of the fixing bolts and locking nuts can affect the axial tilt of the central shaft and affect whether the central shaft will bulge. The compressor impeller disk and turbine disk are used to simulate the counterweight disk. By adjusting the weight and number of fixing bolts, the unbalanced state of the central shaft is simulated.

2. The electric-assisted turbocharger rotor test bench according to claim 1, characterized in that, Elastic sealing rings are installed between the central shaft and the compressor wheel seat and the turbine seat, with two elastic sealing rings respectively installed on the central shaft and the turbine seat.

3. An application of an electrically assisted turbocharger rotor test bench, based on the electrically assisted turbocharger rotor test bench according to any one of claims 1-2, characterized in that, By applying different torques to the lock nut with a torque wrench, the magnitude of the axial preload is changed. The thrust limit bearing is used to fix the axial displacement while transmitting the axial preload, thus pressing the shaft system components together. The compressor impeller and turbine disk are machined with graduations to obtain static contact deformation. By using the relationship between the metal parts machining process parameters, a structural static contact parameter identification experiment is conducted. The shaft system components include the shaft sleeve and the motor rotor.

4. An application of an electrically assisted turbocharger rotor test bench, based on the electrically assisted turbocharger rotor test bench according to any one of claims 1-2, characterized in that, Several motor rotors with different inner diameters are machined, and the fitting parameters are adjusted by controlling the different fitting forms and small clearance fitting amounts with the central shaft. Dynamic characteristic experiments of compressor impeller and turbine disk at different speeds are carried out by using displacement sensors and eddy current sensors.

5. An application of an electrically assisted turbocharger rotor test bench, based on the electrically assisted turbocharger rotor test bench according to any one of claims 1-2, characterized in that, By adjusting the weight and number of counterweight bolts on the counterweight plate, the unbalanced mass of the central shaft is constructed; experiments are conducted on the impeller dynamic characteristics, motor rotor amplitude, and shaft center trajectory at different speeds to simulate classic fault and assembly problem experiments.

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