Force Of Bearing Research Articles

Stability analysis of nonlinear synchronous vibration in an inclined rotor system supported by journal bearing with variational gravity

In vertical rotating shaft-bearing systems, synchronous vibration undergoes destabilization and stabilization owing to the self-excited vibration. Recently, these phenomena have been clarified numerically, experimentally, and analytically based on a newly proposed analytical method. In this method, a two-step linearization of the nonlinear journal bearing (JB) force and generalized eigenvalue analysis are proposed to directly determine the stability of the synchronous orbit. However, this method cannot be used directly for inclined-rotor systems with a large gravitational effect. Moreover, stability changes caused by gravity variations in inclined-rotor systems have not been fully investigated. This study extended the analytical method to one with weighted average dynamic coefficients to efficiently predict the stability changes of synchronous whirling vibrations in inclined rotor systems. The extended analytical method clearly clarifies gravity-induced stability changes in comparison with the numerical (shooting) method. Our analytical method enhances the ability of rotor dynamics software to calculate the stability thresholds of inclined rotor systems with gravity variations.

A study on the temperature rise characteristics of high-speed ball bearings under starvation lubrication

Purpose This paper aims to study the problem of starvation lubrication of high-speed ball bearings due to temperature rise during operation and to avoid thermal failure of bearing lubrication. Design/methodology/approach Under the quasi-statics model of grease lubrication, both the oil film dragging force and the rolling friction between the balls and raceways collectively counteract the gyroscopic torque. Initially, the static model for grease lubrication is solved, followed by calculating the generated heat using the local heat generation method and ultimately the multinodal thermal network model is solved, and the solved results of the quasi-statics are updated by the temperatures of the grease nodes based on the relationship of the grease temperature and viscosity, as well as the relationship of the viscosity and the film thickness. Findings By comparing the numerical calculation results of bearings under different working conditions, the influence of starvation lubrication on the oil film thickness, oil film drag force and rolling friction of bearings is discussed, and it is found that the numerical calculation results of the outer ring temperature of bearings under the starvation lubrication due to the consideration of temperature rise are closer to the experimental values. Originality/value This study reveals the dynamic characteristics of bearings under starvation lubrication, which is more practical and engineering guiding significance for the design of bearings, and introduces a new method and basis for the calculation of temperature rise of rolling bearings. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2024-0208/

Study on the 2D equivalent nonlinear dynamics simulation model related to high speed precision bearing and spindle

The stiffness and contact stress of the bearing spindle system are the key factors affecting its machining accuracy and service life under the condition of high-speed service, which will be affected by different structural parameters and service conditions. It is essential to establish an efficient and accurate computational simulation model to understand the influence of complex factors on the nonlinear dynamic characteristics of the bearing spindle system. Firstly, in the paper, a 2D axisymmetric finite element model of the bearing, aims at the relationship between stiffness and contact stress of the bearing under high-speed service, has been built based on a classical dynamic analysis model and the reversed method of material parameters of equivalent rolling balls. Additionally, for the BT30 spindle, the 2D axisymmetric finite element model of the bearing spindle system also has been built and applied in mechanical analysis of spindle under different conditions of assembly and service, based on the bearing model. The results show that the axial force of bearings decreases as the rotational speed increases, and an augmentation in speed will result in a reduction in the axial stiffness of the BT30 spindle. In addition, the maximum contact stress exhibits a slight decline as the rotational speed increases. Furthermore, with an escalating preload, the stiffness and contact stress of the spindle undergo substantial increments, however, these parameters will cease to alter once a certain threshold is reached.

Study on the wear characteristics of cylindrical needle bearings on the crankshaft of RV decelerator

PurposeThe purpose of this study is to systematically analyze the wear of cylindrical needle bearings in rotary vector reducers under temperature rise and identify the influencing factors.Design/methodology/approachBased on the dynamic characteristics of the RV-20E reducer, the time-varying contact force of the cylindrical needle bearing and the entrainment speed of the inner and outer raceways were calculated. A mixed elastohydrodynamic lubrication model of the needle bearing, considering friction and temperature rise, was established using a dynamic rough tooth surface model. The model solved for the oil film thickness, contact stress and wear conditions of the bearing raceway contact area. The effects of the number of rolling needles, the diameter of rolling needles and surface strength on the wear characteristics were analyzed.FindingsThe results of this study show that the oil film thickness, oil film pressure and surface scratches of cylindrical needle bearings exhibit an uneven, patchy distribution under the combined effects of friction and temperature rise. When the radius of the rolling needle is less than 1.44 mm, inner ring wear is less than outer ring wear. Conversely, when the radius exceeds 1.44 mm, inner ring wear is greater. The optimal rolling needle radius is 1.6 mm. Increasing the number of rolling needles and enhancing the yield strength of the contact surface significantly extend bearing life.Originality/valueThis study provides valuable recommendations for optimizing bearing structural parameters and material characteristics in the design of rotary vector reducers.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2024-0242/

Failure Analysis for Overall Overturning of Concrete Single-Column Pier Bridges Induced by Temperature and Overloaded Vehicles.

Several overloaded-induced overturning incidents of girder bridges with single-column piers have occurred in recent years, resulting in significant casualties and economic losses. Temperature, in addition to overloading, may also play a role in exacerbating bridge overturning. To investigate the association between temperature and bridge overturning, an explicit finite element model (EFEM) of a three-span concrete curved continuous bridge considering nonlinearities was developed to simulate overall collapse. The effects of uniform and gradient temperatures on the overall overturning stability of curved and straight bridges were evaluated based on the EFEMs. Furthermore, the temperature-bridge coupling model and temperature-vehicle-bridge coupling model were utilized to examine how gradient temperature influences bridge overturning. The results show that the overall overturning collapse of a bridge follows four stages: stabilization, transition, risk and overturning. Variations in uniform temperature from -30 °C to 60 °C had a negligible effect on the ultimate vehicle weight for bridge overturning, with a variation of less than 1%. As the gradient temperature ranged from -30 °C to 60 °C, curved bridges show less than a 2% variation in ultimate vehicle weights, compared to a range of -6.1% to 11.7% for straight bridges. The torsion caused by positive gradient temperature in curved bridges can exacerbate bridge overturning, while negative gradient temperature in straight bridges can lead the girder to 'upward warping', facilitating girder separation from bearings. Monitoring the girder rotation angle and vertical reaction force of bearings can serve as important indicators for comparing the stability of bridges.

A Disturbance Compensation Control Strategy for Rotational Speed Standard Device Based on AMB System.

The rotational speed standard device that can carry loads is the key device for calibrating passive rotational speed sensors. The rotor of the passive rotational speed sensor is connected to the rotor of the standard speed device through a coupling, and the standard reference speed is provided by the standard device. Due to the rotor eccentricity, the unbalanced force of the rotor occurs, and it can not only affect the rotational speed accuracy but can also damage the mechanical bearings of the standard speed device. To solve this issue, a method for suppressing the unbalanced force of the speed standard device based on an active magnetic bearing (AMB) force compensation system is proposed. First, the overall structure of the system is briefly introduced. Then, the force feedback control system model with the AMB as the force actuator is established, and a PI controller is designed to achieve the disturbed force control. Finally, a semi-physical simulation experimental platform is built to verify the effectiveness of the proposed method. The experimental results show that the AMB force compensation system can reduce 84.4%, 81.6%, and 79.8% of the unbalanced vibration force at the frequency of 30 Hz, 90 Hz, and 150 Hz, respectively.

Study on the Vibration Characteristics of the Helical Gear-Rotor-Bearing Coupling System of a Wind Turbine with Composite Faults

As the core component of the wind turbine generation gearbox, the gear-rotor-bearing transmission system typically operates in harsh environments, inevitably leading to the occurrence of composite faults in the system, which exacerbates system vibration. Therefore, it is necessary to study the vibration characteristics of wind turbine helical gear-rotor-bearing transmission systems with composite faults. This paper uses an improved energy method to calculate the theoretical time-varying mesh stiffness of a helical gear with a root crack failure. On the premise of considering the time-varying meshing stiffness of the faulty helical gear, the gear eccentric fault, and the nonlinear support force of the faulty bearing, a multi-degree-of-freedom helical gear-rotor-bearing transmission system with compound faults was established by using the lumped parameter method. The dynamic model of the system was solved based on the Runge–Kutta method, and the vibration response of the system under healthy conditions, single faults with gear eccentricity, single faults with tooth root cracks, and coupled bearing composite faults were simulated and analyzed. The results show that the simulation results based on KISSsoft software 2018 version verify the effectiveness of the improved energy method; the existence of single faults and composite faults will cause the fault characteristics in the time domain and frequency domain responses. In this paper, the influence of a single fault and a complex fault on the time domain and frequency domain of the system is mainly discovered through the fault study of the helical rotor-bearing system, and the influence of the fault degree on the vibration of the gear motion system is discussed. The greater the degree of the fault, the more vibration of the system occurs; accordingly, when the system is under the coupling of tooth root crack and bearing fault, there is a significant difference compared with the healthy system and the single fault system. The system vibration has obvious time domain and frequency domain signal characteristics, including periodic pulse impacts caused by gear faults and time domain impact caused by bearing. The fault characteristic frequencies can also be found in the frequency domain. In this paper, the fault study of a helical gear of wind turbine generation provides a reference for the theoretical analysis of the vibration characteristics of the helical gear-rotor-bearing system under various fault conditions, lays a solid foundation for the simulation and subsequent diagnosis of the composite fault signal of the system, and provides help for the fault diagnosis of wind turbine gearboxes in the future.

Friction Evolution of Graphite Bearing Impregnated with Polymer Subjected to Vibration Fretting at High Temperature

To address friction and wear challenges in dry contacts, manufacturers often employ self-lubricating materials. Graphite and its derivatives stand out as particularly suitable due to their exceptional tribological properties. However, under intense friction conditions, graphite can experience a decline in lubricating efficiency due to severe abrasive wear. This abrasive damage results in elevated activated carbon surfaces with increased surface energy, fostering greater adhesion between sliding surfaces. The low friction coefficient of graphite is not an inherent property but rather a consequence of water vapor adsorption by the material. Beyond 150 °C, desorption of the vapor occurs, leading to a transition in the friction coefficient from µ = 0.1 to µ = 0.6. To address this issue, impregnation solutions for self-lubricating materials have been developed, with various compositions tailored to specific objectives. Common types include molybdenum disulfide, soft metals and polymers. In this predominantly experimental study, the impact of polymer impregnation on the evolution of friction force and wear rate in graphite material bearings subjected to a dry fretting contact under severe thermal stresses at 270 °C was investigated. Additionally, the mechanical stresses in the bearings throughout different phases of our tests were analyzed using a numerical model.

Dynamics model and vibrational response analysis of helical gear-rotor-bearing transmission system

As a core component of wind turbines, wind power gear speed increasers often work in harsh environments, so it is necessary to study the vibration characteristics of gear transmission systems. Taking a wind turbine gearbox high-speed stage helical gear transmission system as the research object, the dynamics model of multi-degree-of-freedom helical gear-rotor-bearing transmission system is established by the lumped parameter method and solved by Runge-Kutta method, taking into account the tooth side clearance of the gear, transmission error, eccentricity and support force of the nonlinear bearing. The effects of input torque, transmission error and tooth side clearance on the vibration characteristic response of the helical gear train were analyzed. The relationship between the trend of amplitude change in each direction of the gear and the trend of change in the major frequency components was analyzed under the conditions of changing internal and external excitation. The results show that torsional vibration dominates in the system. As the input torque increases, the vibration amplitude of the driving and driven gears decreases, and the frequency amplitude decreases significantly at multiple locations. Gear transmission errors and changes in tooth side clearance have significant effects on gear vibration amplitudes, but are sensitive only to the meshing frequency. The trend of gear vibration amplitude caused by the change of external excitation of the gear set is synchronized with the trend of main frequency amplitude in the corresponding direction, while the change of vibration amplitude caused by internal excitation is consistent with the trend of mesh frequency amplitude in the corresponding direction. The results of this paper can pave a certain foundation for the design and fault diagnosis of wind power gearbox transmission system.

Determination of dynamic component reactions in support bearings of rotor saws for cutting hot rolled (message 1)

A distinctive feature of rotary saws is the process of cutting the workpiece, which takes a very short time. For example, a workpiece with a diameter of 200 mm is cut in 0.2 seconds, while traditional designs of sliding and pendulum saws perform this operation in 10-20 seconds or more. This effect is achieved due to the high speeds of feeding the disc to the cut, exceeding traditional modes by 20 or more times. However, due to the specific cutting conditions, weak links were identified in these designs that require further improvement. One of the factors that reduces the reliability of the saw is the insufficient durability of the bearings of the high-speed disk shaft, which perceives the cutting force. Until now, the reliability issues of rotary saw structures remained unresolved. One of the factors that reduces the reliability of the saw is the insufficient durability of the bearings of the high-speed disk shaft, which perceives the cutting forces. Practice shows that the applied methods of calculating the strength of support bearings do not allow taking into account all possible factors that affect the reliability of bearings in the cutting process. First of all, as it turned out, during operation, the saw blade has radial runout, possibly due to an error when cutting the teeth of the blade and the eccentric landing of the blade on the seat when replacing it. For modern rolling mill production, the issue of strength and reliability of rotary saw designs, which are intended for cutting rolled metal, is relevant. The purpose of this work is to determine the precise values of the reaction forces of the support bearings of the disc shaft. As you know, during long-term operation of the object, the place for landing the cutting disc on the faceplate wears out, sometimes there is an error in the hole when making a new disc. Therefore, there is an eccentricity of the center of gravity of the disk. The presence of this eccentricity is taken into account in the work when determining the required forces using D'Alembert's principle of conditional balancing of forces. Due to the fact that the process of cutting with a circular saw is very short-term, the cutting force is considered the impact force. The magnitudes of the reaction forces in the bearings are determined during cutting using the impact dynamics theorems: the momentum theorem and the kinetic momentum change theorem. By projecting the vector formulas of the principle and theorems on the coordinate axis, the systems of algebraic equations are obtained, from which the horizontal and vertical components of the reaction forces in the bearings are determined both in idle mode and during cutting. Due to the fact that the vector of the centrifugal Dalembert force of inertia of the disk changes its direction, the formulas of the reaction forces at different positions of the center of gravity of the disk were obtained. According to the results of the planned numerical analysis of the problem, graphs of the dependences of the horizontal and vertical components of the pressure forces on the bearings can be drawn from: the eccentricity value, the vertical and horizontal components of the cutting forces, the angular velocity and the position of the disk

The inter‐history iteration method for seismic response analysis of seismically isolated structures and its secondary development based on ABAQUS

SummaryIn seismic response analysis of seismically isolated structures (SISs), the nonlinearity is concentrated in the isolation layer while the upper structure behaves linearly, making SISs locally nonlinear systems. This paper proposed a novel seismic analysis method based on equivalent linearization (EL) and iterative solution for SISs. In this method, the equilibrium equations of an SIS are expressed by the second‐order ordinary differential equations of the structural system as well as the hysteretic force of seismic isolation bearings (SIBs). Based on EL theory, the linearized equilibrium equations of the overall system were reconstructed in which the EL parameters are derived theoretically. The inter‐history iteration (IHI) method was proposed to solve the linearized equation system and calculate the EL parameters in sequence iteratively for seismic response analysis of SISs, thus reducing computational cost without excessive loss of accuracy. In addition, the secondary development of the proposed method was programmed in ABAQUS for ease of engineering applications. Finally, the convergence and accuracy of the method were investigated through numerical simulation of an SIS case study. As the numerical investigation indicates, the proposed method considers the coupling between structural response and the EL parameters, achieving a high convergence rate and satisfactory solution accuracy. The ABAQUS secondary development program utilizes the powerful pre‐processor, post‐processor, and solvers of ABAQUS, making the IHI method more appropriate for engineering applications.

Dynamic modeling and analysis of two-span rotor-pedestal system with bearing tilt and extended defect: Simulation and experiment

When the rolling bearing raceway is tilted, the contact load of the raceway increases, which may greatly increase the occurrence of raceway defects. However, the evolution law of the raceway defect extension process on the system dynamic characteristics is not clear when the bearing is tilted. In this paper, considering the influence of rough surface caused by the extension of bearing defects, a mathematical model of raceway extension defects which is more consistent with the actual morphology is proposed. The model can be used to evaluate the damage degree of the bearing raceway of rotating machinery. Taking the two-span rotor-bearing-pedestal system of the test rig as the research object, a nonlinear dynamic model of the system is established considering the nonlinear supporting force of bearings and pedestal, shaft coupling looseness and other nonlinear factors. The effectiveness of the bearing fault characterization model and the system dynamics model is verified by experiments. On this basis, the influence of tilt on bearing fault and the change rule of raceway defect extension on bearing contact characteristics and system dynamic characteristics are discussed. The results indicate that raceway tilt aggravates system vibration caused by the bearing defect. With the increase of the defect range, the impact vibration characteristics weaken, and the roughness of the raceway surface in the defect area has a great influence. However, with the increase of defect depth, the influence law is just the opposite. The research results are expected to provide theoretical support for bearing fault diagnosis of rotating machinery systems.

Force-based feedforward control of persistent synchronous rotor/touchdown bearing contact in active magnetic bearing systems

Touchdown bearings are installed in active magnetic bearing systems to protect system components and prevent rotor contact with stator laminations. Abnormal conditions may induce a rotor dynamic response that leads to persistent contact with the touchdown bearings. Control schemes may be successful in re-levitating the rotor from contact provided the underlying contact dynamics are taken into consideration. Effective rotor/touchdown bearing contact control is opportune when active magnetic bearings remain operational and complete machine rundown is avoidable. In such cases, the active magnetic bearing forces should have the required dynamic load capacity to restore contact-free rotor levitation, eliminating the need for extra actuation in the system. This requires establishing a relationship between contact dynamics and magnetic bearing control forces. This paper presents a new contact control method based on stator strain measurement arising from rotor/touchdown bearing contact. The measurement data are utilised to evaluate frequency dependent magnetic bearing control forces and phase shifts to enable rotor recovery from contact. The control method is tested and validated experimentally on an active magnetic bearing system with a long unbalanced flexible rotor. The tests demonstrate effective rotor recovery from persistent synchronous contact over a range of rotor speeds.

Support Force and Load Distribution Analysis of Angular Contact Ball Bearing Considering Rotor Deformation

Support Force and Load Distribution Analysis of Angular Contact Ball Bearing Considering Rotor Deformation

Influence of complex loading of radial bearings of the oscillation groups of liquid propellant engine steering gear on the frictional moment

The paper presents a method for determining the frictional moments of the oscillation groups of the most widespread domestically made liquid propellant engine steering units. This is a topical issue requiring investigation to improve the efficiency and reliability of oscillation groups. The reason for the occurrence of an additional axial force in the radial bearings of the articulated joints that leads to an overestimation of the actual values of the moments relative to the theoretical values is shown. The procedure for calculating the maximum axial force and the accompanying increase in the moment, confirmed by the analysis of the results of the bench test of the experimental steering unit, is presented. An assessment of the range of axial forces in the absence of blocking of the axial movement of the bearing was carried out with a simultaneous analysis of the suitability of the existing methods for calculating the increase in the frictional moment for the obtained ratios of axial and radial loads. The direction of further research of low-speed radial bearings is determined, aimed at increasing the reliability of calculations and developing measures to minimize the frictional moment of production oscillation units.

Study of Hydrodnamic Pumping Effects of Fixed Axis Rotation in Eccentric Annular Flow Field

Hydrodynamic effect is one of the key phenomena in journal bearing lubrication. Many researches have been carried out on the supporting force of journal bearing, the motion of suspension shaft and the lubrication effect. This paper studies the hydrodynamic effect from another point of view, that is, the pumping effect caused by the rotation of the eccentric shaft with fixed axis. The clearance between the rotor and the stator is divided into two sections by the inlet port and the outlet port. Their mathematical models are established and studied in polar coordinates. The pressure distribution and pumping flowrate in the flow field are studied theoretically. Under the conditions analyzed in this paper, an output flow larger than 90 ml/s could be generated, overcoming a load pressure of 0.5 MPa. In addition, the pressure distribution and pumping flowrate of the mechanism are affected by the pumping outlet orientation. According to the analysis results of the output angle range from π/8 to 3π/4, when the pump outlet angle is set near 3π/8 to π/2, the pumping flowrate reaches the maximum value of 91.83 ml/s, and nearly half 48% of the inflow liquid can be pumped out to the outlet.

Analysis and Compensation of Hysteresis Effect on Electromagnetic Force in Axial Magnetic Bearings

Magnetic bearings (MBs) enable the rotor to run at high speed without lubrication due to no mechanical contact. However, the inherent hysteresis of ferromagnetic materials affects the support characteristics, reducing the design performance and stability margin of MBs, especially for axial MBs using materials with high coercive force. To analyze and compensate for the hysteresis effect on the electromagnetic force in axial MBs, an efficient method is proposed in this paper. Firstly, the hysteresis properties of the ferromagnetic materials are simulated by the Preisach model, and the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</i> - <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> relationships under any external magnetic field can be determined. Taking into account the non-ideal factors such as hysteresis and saturation effects, the nonlinear magnetic circuit model of the axial MBs is established. The magnetic flux density working point under different control currents and eccentric displacements can be determined through iterative calculation, and then the air gap flux density distribution and electromagnetic force of the axial MBs are calculated. On this basis, the adverse effects of hysteresis on the bearing capacity and system stability of axial MBs are analyzed. A compensation algorithm is designed based on the inverse model to reduce the hysteresis effect. The inverse model is approximated modeled by the Lissajous curve. Finally, the proposed analysis and control methods are verified by the finite element method (FEM) or experiments. The results show that the proposed analysis method is capable of accomplishing good accuracy and requires less computation time than FEM, it can be applied to arbitrary current variation processes. In addition, the phase lag of the system is effectively improved with the compensation algorithm.

Dynamic characteristics analysis of a coaxial rotor system with shared bearing bore structure

The nonlinear dynamic model of a shared bearing bore-coaxial rotor system was established with nonlinear forces of the rolling bearings and squeeze film dampers considered, Cross coupling frequency was found in cross coupling vibration simulation. Numerical studies were conducted to reveal the mechanism of the coupling vibration for the shared bearing bore-coaxial rotor system. The coupling vibration characteristics and influencing factors of the shared bearing bore-coaxial rotor system were studied. The results show that the coupling vibration is featured by cross-excitation phenomenon and orbit which shows a “circle in circle” pattern. Besides, the angular stiffness of the shared bearing bore has great influences on the coupling vibration. However, the radial stiffness has almost no effect on the coupling vibration.

Nonlinear Vibration of Bolted Rotor Bearing System Accounting for the Bending Stiffness Characteristics of the Connection Interface

This paper considers the discontinuous characteristics of a real aero-engine rotor system, that is, the existence of bolted connection characteristics, and establishes a new bolted connection rotor system model. Taking into account the bending stiffness and the nonlinear Hertzian contact force of the rolling bearing, the Newmark-[Formula: see text] numerical method is used to solve the system response, and the influence of the bending stiffness on the system is studied. Moreover, the effects of bending stiffness and eccentricity on the system dynamics are analyzed. The results show that the nonlinear phenomena of the system are more abundant and the critical speed of the system is higher when the bending stiffness is involved. With the increase of bending stiffness, the critical speed of the system increases, and the frequency component of the system becomes more complex. Then, the influence of eccentricity on the system is studied based on the bending stiffness. It is found that the greater the eccentricity, the greater the critical speed of the rotor and the greater the amplitude of the main frequency. In the case of the same eccentricity, the main frequency increases as the rotational speed increases, and the frequency doubling component appears in the 2-period motion. This paper provides a basis for predicting the nonlinear response of bolted rotor-bearing system.

The Effect of the Fillets on Submarine Wake Field and Propeller Unsteady Bearing Force

The uniformity of the wake on the submarine propeller disk is the key factor affecting the vibration and noise performance of the propeller. To study the influence of the fillets on the uniformity of submarine wake field and propeller unsteady bearing force, the submarine resistance calculation and self-propulsion calculation were carried out using the Detached-Eddy Simulation (DES) method. The characteristics of the wake field and hydrodynamic performance of the original and improved plan were compared and analyzed in detail. The fillets improve the wake distribution at the propeller disk by reducing the horseshoe vortex, and the fillets mainly affect the flow field characteristics of the inner radius area. The fillets can effectively reduce the axial velocity pulsation and improve the quality of the wake field. The frequency–domain curve shows that the bearing force and torque pulsation value of the improved plan are smaller than that in the original one, indicating that the fillets are conducive to controlling the vibration and noise performance of the submarine propeller. The results show that the fillets can effectively improve the flow field quality in the wake fields and reduce the propeller unsteady bearing force.