Minimum Load Requirements for the Prevention of Skidding in High Speed Thrust Loaded Ball Bearings

Boness, R. J.

doi:10.1115/1.3251611

Cited by 10 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hirano [10] carried out an experimental investigation on the ball motion inside an axially loaded angular contact ball bearing, and found that the gross-sliding of rolling-elements occurs when the value of the parameter zF c /F a exceeds 0.1, where z, F c and F a denote the number of balls in the bearing, centrifugal force acting on the ball and applied thrust load respectively. However, it has been established by Poplawaski [7] and Boness [11] that this parameter alone is not sufficient to completely define the roll-slip behaviour of a ball bearing.…”

Section: Introductionmentioning

confidence: 99%

A dynamic model to predict the occurrence of skidding in wind-turbine bearings

Jain¹,

Hunt²

2011

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Abstract. Despite use of the best in current design practices, high-speed shaft (HSS) bearings, in a wind-turbine gearbox, continue to exhibit a high rate of premature failure. As HSS bearings operate under low loads and high speeds, these bearings are prone to skidding. However, most of the existing methods for analyzing skidding are quasi-static in nature and cannot be used to study dynamic operating conditions. This paper proposes a dynamic model, which includes gyroscopic and centrifugal effects, to study the skidding characteristics of angularcontact ball-bearings. Traction forces between rolling-elements and raceways are obtained using elastohydrodynamic (EHD) lubrication theory. Underlying gross-sliding mechanisms for pure axial loads, and combined radial and axial loads are also studied. The proposed model will enable engineers to improve bearing reliability at the design stage, by estimating the amount of skidding. IntroductionWind energy is the fastest growing renewable energy sector with an average annual growth rate of around 30% during last 10 years. In order to harvest energy most efficiently and reliably, various wind-turbine design concepts have been developed over the years. Most of the modern wind-turbine designs utilize a gearbox which connects the rotor-shaft to high-speed shaft, and increases rotational speed from 15-30 rpm (at blades) to 1000-1800 rpm -the speed required by most generators to produce electricity. As wind-turbines have grown larger, gearbox failure rates have gone up as well. Since gearbox is one of the most expensive components of a wind turbine, higher-than-expected failure rates increase the cost of energy production. For a typical turbine, 20% of the downtime is due to gearbox failures and an average gearbox failure takes about 250 hours to repair [1].Most of the problems in wind turbine gearboxes appear to emanate from bearings [2]. Bearings supporting the high speed shaft exhibit a high rate of premature failure and are identified as one of the most critical components [1,2]. These bearings operate under low loads and high speeds, and therefore, are prone to skidding, i.e., gross-sliding of rolling-elements on raceways. Sliding can lead to rolling surface distress and eventually to premature failure. Hence, skidding is an important design criterion for wind-turbine bearings. Both ball-bearings and roller-bearings are commonly used to support HSS. The focus of this work is on angular-contact ball-bearings.Researchers have developed numerous analytical and numerical models of varying complexity to understand the skidding behaviour of bearings. Jones [3,4] developed the first mathematical theory to analyze the motion of rolling-elements in ball bearings. He evaluated the frictional

show abstract

Section: Introductionmentioning

confidence: 99%

A dynamic model to predict the occurrence of skidding in wind-turbine bearings

Jain¹,

Hunt²

2011

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

show abstract

“…The effects of rotational speed, load, number of rolling elements and lubricants on the skidding behaviour of bearing were investigated. Boness and Gentle 6–8 developed aquasi-static model to analyse the ball motion in ball bearings and achieved good agreements with experimental results. An empirical formula of the critical thrust load to prevent the gross skidding in angular-contact bearings was also proposed.…”

Section: Introductionmentioning

confidence: 79%

Investigation of the dynamic local skidding behaviour of rollers in cylindrical roller bearings

Luo

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part K:

View full text Add to dashboard Cite

Skidding has a great influence on the reliability and the life of rolling element bearings. The previous research of bearing skidding mainly focussed on the gross skidding of bearings under severe conditions. However, the local skidding of rolling element also exists and cannot be ignored when bearing normally runs at steady state. In this paper, considering the discontinuous contact between the roller and the cage, the Hertz contact between the roller and races, lubrication, centrifugal effects and the cage pocket clearance, a nonlinear dynamic model is established to investigate the local skidding behaviour of a roller in cylindrical roller bearings. The equations of the dynamic model are solved by the fourth-order Runge–Kutta algorithm and verified by comparing simulation results with the published experimental data. The results show that the local skidding of the roller still noticeably exists in bearings even when the gross skidding can be ignored, especially on the inner raceway. The local skidding at the entry of the loaded zone may cause the smearing on the raceway surface. However, it can be found that the probability of the local skidding of the roller will be decreased by increasing radial load and reducing the bearing rotational speed. The cage pocket clearance would induce violent fluctuations on the roller rotational angular velocity as well as on the sliding velocity. Furthermore, it can generate extraordinary impact forces between the rollers and the cage. Thus, the cage pocket clearance should be carefully considered in the design of bearings.

show abstract

“…Great care must be taken to effectively choose the structure parameters and operating parameters of the bearing for the design of the rotor bearing system. centre of curvature of the outer ring groove R c2 centre of curvature of the inner ring groove Q 1 contact load between the ball and outer ring Q 2 contact load between the ball and inner ring X 2 bearing displacement in the x-direction Y 2 bearing displacement in the y-direction Z 2 bearing displacement in the z-direction α 0 initial contact angle ω rotating speed of the rotor φ i angular location of the ith rolling element δ 1i contact deformation between the ball and outer race δ 2i contact deformation between the ball and inner race…”

Section: Discussionmentioning

confidence: 99%

“…Harris [1] gives an analytical method to predict skidding using quasi-static equations. Boness [2] presents a simple empirical equation to compute the minimum load for preventing skidding in ball bearing. Gupta and Meeks [3,4] establish a sophisticated dynamic equation to study the dynamic property of the ball bearing.…”

Section: Introductionmentioning

confidence: 99%

Study on dynamic characteristics of angular ball bearing with non-linear vibration of rotor system

Cui

et al. 2008

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

A rotor system supported by an angular ball bearing displays very complicated nonlinear behaviour due to non-linear Hertzian contact force. The non-linear force and moment caused by the ball bearing are calculated on the basis of the relationship between deflection, and five-degree-of-freedom dynamic equations of the rotor ball bearing system are established. The Newmark-β method and the Newton-Raphson method are used to solve the non-linear equations. The dynamic characteristics of angular ball bearings are computed, considering the non-linear vibration of the rotor system. Taking angular ball bearing QJS208ACQ4C1/HNP4 as an example, the effects of the vibration of the rotor system on bearing dynamic characteristics are analysed. The results show that the spin-to-roll ratio of balls, the slide ratio of the cage, and stiffness of the bearing all vary obviously with the non-periodic vibration range of the rotor; initial contact angle and axial load of the ball bearing change the non-linear dynamic nature of the rotor system and dynamic characteristics of the bearing. The rotor ball bearing system can work stably by choosing the structural and operation parameters reasonably.

show abstract

Minimum Load Requirements for the Prevention of Skidding in High Speed Thrust Loaded Ball Bearings

Cited by 10 publications

References 0 publications

A dynamic model to predict the occurrence of skidding in wind-turbine bearings

A dynamic model to predict the occurrence of skidding in wind-turbine bearings

Investigation of the dynamic local skidding behaviour of rollers in cylindrical roller bearings

Study on dynamic characteristics of angular ball bearing with non-linear vibration of rotor system

Contact Info

Product

Resources

About