Discrete theory of rolling elements for a cageless ball bearing

Zhao, Yanling; Wang, Qiyu; Wang, Mingzhu; Pan, Chengyi; Bao, Yudong

doi:10.1007/s12206-022-0329-x

Cited by 4 publications

(5 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where υ 1 , υ 2 , E 1 and E 2 are the Poisson's ratio, elastic modulus of the materials of the rolling elements and the variable diameter raceway. R * is the equivalent radius of curvature at the contact point in Equation (3). According to the geometrical characteristics of the variable diameter raceway, the equivalent radius can be obtained from Equation ( 5):…”

Section: Analysis Of Contact Stress Distribution Between Rolling Elem...mentioning

confidence: 99%

“…With the increasing application of high-speed equipment such as control systems for rocket engines and fans, the cageless bearing is used as the protective bearing of the electromagnetic bearing rotor system, the discrete performance of rolling elements is the premise to ensure the smooth operation of rotor [1,2]. The design of the local variable diameter raceway in the outer ring of bearing is a method to realize the discretization of rolling elements [3]. Considering the particularity of the local variable diameter raceway structure, when the rolling elements pass through the variable diameter raceway, the contact characteristics between the rolling elements and the bearing raceway change.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of Contact Stress Distribution between Rolling Element and Variable Diameter Raceway of Cageless Bearing

2022

Self Cite

View full text Add to dashboard Cite

The change in contact state between the rolling elements and raceway of a cageless bearing with a variable diameter raceway affect the wear of the bearing, which leads to discrete motion failure of the rolling elements. For this purpose, the contact characteristics as contact form and contact stress between the rolling elements and raceway were determined. A numerical method is proposed to determine the three-dimensional contact stress of a cageless bearing. First, combined with the variable diameter raceway structure characteristics and the motion of rolling elements, the rolling elements and raceway contact stress model was established, and the influence factors of contact stress and the maximum stress distribution were determined. Based on the rolling contact theory, the relative position of the stick-slip region and the tangential stress distribution of the contact area were analyzed. The stress equations for the three-dimensional between rolling elements and variable diameter raceway were obtained by the principle of superposition, and the stress component characteristics of the contact area were numerically simulated. The results show that the main influencing factors of contact stress are: load, structure of variable diameter raceway, spindle speed, friction coefficient µ and the ratio of the stick region and the slip region k. Taking a cageless bearing as an example, the influence of the contact curvature Ri on the contact stress is smaller than that of ri. Increasing ri to make it larger than 1.5 mm and controlling the speed to be lower than 13,950 r/min, the maximum stress appears in the conventional raceway, which is beneficial to alleviate the failure of the variable diameter raceway. There are a slip region and a stick region in the contact area, reducing the friction coefficient µ and increasing the stick-slip coefficient k appropriately can ensure the discrete movement of the rolling elements and reduce the wear of the variable diameter raceway. The error of the stress distribution model is less than 15%, which can predict and characterize the contact stress distribution between the rolling elements and the variable diameter raceway. The theoretical guidance for the development and application of cageless bearings is provided.

show abstract

Section: Analysis Of Contact Stress Distribution Between Rolling Elem...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis of Contact Stress Distribution between Rolling Element and Variable Diameter Raceway of Cageless Bearing

2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…As the core part of the magnetic floating bearing, the outer ring of the cageless protection bearing often adopts the local functional groove to keep the rolling element automatically discrete because it often rotates at high speed to make the local functional groove wear, so it is especially important to explore its wear texture [1,2].…”

Section: Introductionmentioning

confidence: 99%

Characterization of Microscopic Damage Evolution of Functional Groove in Cageless Bearings

et al. 2023

Self Cite

View full text Add to dashboard Cite

Bearings with partial function grooves as cageless bearings related to magnetic floating bearing protection have characteristics, such as fast offsetting of the impact force caused by rotor fall, and they gradually become important parts of ultra clean and cryogenic transportation systems. However, the functional failure mechanism of the bearing, which is caused by functional groove wear, is not clear. Therefore, this paper establishes a force–motion intrinsic model of particles inside the functional groove, which is based on the discrete element method, which it itself combined with the functional groove damage evolution trend analysis. Then, a hyper-quadratic surface model of inter-particle contact is established to simulate the time-varying friction coefficient of the functional groove by combining particles of different sizes to form particle clusters. Additionally, as the boundary condition, EDEM is used to solve the contact motion state of rolling element rolling through the functional groove for one week to obtain the overlap between particles and contact force change law. The results show that the wide side of the functional groove wears more seriously than the narrow side, and the rolling element leaves the functional groove with more impact than when it enters the functional groove, and the functional groove wears more seriously. In this paper, through the study of local functional groove wear of cageless ball bearing, we propose to characterize the damage extension of functional groove by using the number of particle fracture and motion trend in discrete element method, and this study provides theoretical guidance for the design of cageless bearings.

show abstract

“…Collisions among rolling elements in cageless bearings occur due to the absence of a cage. To achieve the stability of cageless bearings, Zhao et al proposed a method of setting a reduced collision groove in the outer raceway to make the rolling elements discrete [ 1 , 2 ]. However, the constant contact between the rolling elements and the discrete groove will lead to wear of the discrete groove, which will affect the discrete rolling elements [ 3 ].…”

Section: Introductionmentioning

confidence: 99%

Characterization of Bond Fracture in Discrete Groove Wear of Cageless Ball Bearings

et al. 2022

Self Cite

View full text Add to dashboard Cite

Cageless ball bearings with discrete grooves in the outer raceway enable the dispersion of rolling elements. Once worn, the discrete groove can cause the rolling element to discretely fail. This paper presents the discrete element method to investigate the wear of discrete grooves in cageless bearings from the standpoint of bond fracture. In conjunction with the structural characteristics of bearing races with discrete slots, we propose a hexagonal close-spaced spherical particle arrangement, in which the discrete slots are discretized into particles of the same size that are connected by bonds. The contact model and contact force equation between the rolling elements and the aggregate elements are established, and the external force on the aggregate elements is calculated. Under the influence of an external force and the arrangement of particles in the aggregate element, the internal force transfer equation of different layers and different particles is derived, and the internal force of the particles in the aggregate unit is calculated. In accordance with Hertz–Mindline theory, the bonding model of discrete groove particles is established, the size of the particle shedding cohesive force during bond fracture is determined, and the wear degree of discrete grooves is characterized by comparing the cohesive force and internal force. Numerical solutions and wear tests are combined. Bond fracture can accurately characterize the wear of discrete grooves. This approach offers theoretical guidance for cageless bearing design.

show abstract

Discrete theory of rolling elements for a cageless ball bearing

Cited by 4 publications

References 16 publications

Analysis of Contact Stress Distribution between Rolling Element and Variable Diameter Raceway of Cageless Bearing

Analysis of Contact Stress Distribution between Rolling Element and Variable Diameter Raceway of Cageless Bearing

Characterization of Microscopic Damage Evolution of Functional Groove in Cageless Bearings

Characterization of Bond Fracture in Discrete Groove Wear of Cageless Ball Bearings

Contact Info

Product

Resources

About