Through-Hardening or Case-Hardening for Tapered Roller Bearings?

In the context of targeted improvements in energy efficiency, secondary rolling bearing contacts are gaining relevance. As such, the elastohydrodynamically lubricated (EHL) roller face/rib contact of tapered roller bearings significantly affects power losses. Consequently, this contribution aimed at numerical optimization of the pairing’s macro-geometric parameters. The latter were sampled by a statistical design of experiments (DoE) and the tribological behavior was predicted by means of EHL contact simulations. For each of the geometric pairings considered, a database was generated. Key target variables such as pressure, lubricant gap and friction were approximated by a meta-model of optimal prognosis (MOP) and optimization was carried out using an evolutionary algorithm (EA). It was shown that the tribological behavior was mainly determined by the basic geometric pairing and the radii while eccentricity was of subordinate role. Furthermore, there was a trade-off between high load carrying capacity and low frictional losses. Thereby, spherical or toroidal geometries on the roller end face featuring a large radius paired with a tapered rib geometry were found to be advantageous in terms of low friction. For larger lubricant film heights and load carrying capacity, spherical or toroidal roller on toroidal rib geometries with medium radii were favorable.

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Tandem tapered roller bearings no-load torque loss in a rear axle gear transmission

Tribology International ◽

10.1016/j.triboint.2021.106876 ◽

2021 ◽

Vol 157 ◽

pp. 106876

Author(s):

Justino A.O. Cruz ◽

Pedro M.T. Marques ◽

Jorge H.O. Seabra ◽

Ramiro C. Martins

Keyword(s):

Rear Axle ◽

Gear Transmission ◽

Load Torque ◽

Roller Bearings ◽

Torque Loss ◽

Tapered Roller ◽

Tapered Roller Bearings

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Steering to success — with tapered roller bearings

Tribology International ◽

10.1016/0301-679x(86)90022-8 ◽

1986 ◽

Vol 19 (3) ◽

pp. 157

Keyword(s):

Roller Bearings ◽

Tapered Roller ◽

Tapered Roller Bearings

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In-Process Measurement for the Process Control of the Real-Time Manufacturing of Tapered Roller Bearings

Materials ◽

10.3390/ma11081371 ◽

2018 ◽

Vol 11 (8) ◽

pp. 1371 ◽

Cited By ~ 2

Author(s):

Francisco Brosed ◽

A. Zaera ◽

Emilio Padilla ◽

Fernando Cebrián ◽

Juan Aguilar

Keyword(s):

Real Time ◽

Measurement Procedure ◽

Axial Loads ◽

Machining Processes ◽

Process Measurement ◽

Roller Bearings ◽

Tapered Roller ◽

Environmental Process ◽

Tapered Roller Bearings ◽

Component Assembly

Tapered roller bearings can accommodate high radial loads as well as high axial loads. The manufacturing process consists of machining processes for ring and component assembly. In this contribution, the parameters of influence on the measurement procedure were studied. These parameters of influence were classified as environmental, process, and machine parameters. The main objective of this work was to optimize the process using real-time measurements, which required the study of the influence of several parameters on the measurement uncertainty and how to correct their effects.

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Discussion: “Fatigue Life of Tapered Roller Bearings” (Clinedinst, W. O., 1937, ASME J. Appl. Mech., 4, pp. A143–A150)

Journal of Applied Mechanics ◽

10.1115/1.4008859 ◽

1938 ◽

Vol 5 (2) ◽

pp. A90-A91

Author(s):

S. Einstein

Keyword(s):

Fatigue Life ◽

Roller Bearings ◽

Tapered Roller ◽

Tapered Roller Bearings

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Comparison of planetary bearing load-sharing characteristics in wind turbine gearboxes

Wind Energy Science ◽

10.5194/wes-3-947-2018 ◽

2018 ◽

Vol 3 (2) ◽

pp. 947-960 ◽

Cited By ~ 1

Author(s):

Jonathan Keller ◽

Yi Guo ◽

Zhiwei Zhang ◽

Doug Lucas

Keyword(s):

Fatigue Life ◽

Wind Turbine ◽

Load Sharing ◽

Position Error ◽

Bearing Clearance ◽

Roller Bearings ◽

Bearing Load ◽

Tapered Roller ◽

Tapered Roller Bearings ◽

Cylindrical Roller

Abstract. In this paper, the planetary load-sharing behavior and fatigue life of different wind turbine gearboxes when subjected to rotor moments are examined. Two planetary bearing designs are compared – one design using cylindrical roller bearings with clearance and the other design using preloaded tapered roller bearings to support both the carrier and planet gears. Each design was developed and integrated into a 750 kW dynamometer tests, the loads on each planet bearing row were measured and compared to finite-element models. Bearing loads were not equally shared between the set of cylindrical roller bearings supporting the planets even in pure torque conditions, with one bearing supporting up to 46 % more load than expected. A significant improvement in planetary bearing load sharing was demonstrated in the gearbox with preloaded tapered roller bearings with maximum loads 20 % lower than the gearbox with cylindrical roller bearings. Bearing life was calculated with a representative duty cycle measured from field tests. The predicted fatigue life of the eight combined planet and carrier bearings for the gearbox with preloaded tapered roller bearings is 3.5 times greater than for the gearbox with cylindrical roller bearings. The influence of other factors, such as carrier and planet bearing clearance, gravity, and tangential pin position error, is also investigated. The combined effect of gravity and carrier bearing clearance was primarily responsible for unequal load sharing. Reducing carrier bearing clearance significantly improved load sharing, while reducing planet clearance did not. Normal tangential pin position error did not impact load sharing due to the floating sun design of this three-planet gearbox.

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