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Bearings and Lubrication
Published in Ansel C. Ugural, Mechanical Engineering Design, 2022
A roller bearing uses straight, tapered, or contoured cylindrical rollers. When shock and impact loads are present or when a large bearing is needed, these bearings are usually employed. Roller bearings can support much higher static and dynamic (shock) loads than comparably sized ball bearings, since they have line contact instead of point contact. A roller bearing generally consists of the same elements as a ball bearing. These bearings can be grouped into five basic types: cylindrical roller bearings, spherical roller bearings, tapered thrust roller bearings, needle roller bearings, and tapered roller bearings (Figure 10.23). Straight roller bearings provide purely radial load support in most applications; they cannot resist thrust loads. The spherical roller bearings have the advantage of accommodating some shaft misalignments in heavy-duty rolling mill and industrial gear drives. Needle bearings are in widespread usage where radial space is limited.
Bearings and Lubrication
Published in Ansel C. Ugural, Youngjin Chung, Errol A. Ugural, Mechanical Engineering Design, 2020
Ansel C. Ugural, Youngjin Chung, Errol A. Ugural
A roller bearing uses straight, tapered, or contoured cylindrical rollers. When shock and impact loads are present or when a large bearing is needed, these bearings are usually employed. Roller bearings can support much higher static and dynamic (shock) loads than comparably sized ball bearings, since they have line contact instead of point contact. A roller bearing generally consists of the same elements as a ball bearing. These bearings can be grouped into five basic types: cylindrical roller bearings, spherical roller bearings, tapered thrust roller bearings, needle roller bearings, and tapered roller bearings (Figure 10.23). Straight roller bearings provide purely radial load support in most applications; they cannot resist thrust loads. The spherical roller bearings have the advantage of accommodating some shaft misalignments in heavy-duty rolling mill and industrial gear drives. Needle bearings are in widespread usage where radial space is limited.
Bearings and Lubrication
Published in Ansel C. Ugural, Youngjin Chung, Errol A. Ugural, MECHANICAL DESIGN of Machine Components, 2018
Ansel C. Ugural, Youngjin Chung, Errol A. Ugural
A roller bearing uses straight, tapered, or contoured cylindrical rollers. When shock and impact loads are present or when a large bearing is needed, these bearings usually are employed. Roller bearings can support much higher static and dynamic (shock) loads than comparably sized ball bearings, since they have line contact instead of point contact. A roller bearing generally consists of the same elements as a ball bearing. These bearings can be grouped into five basic types: cylindrical roller bearings, spherical roller bearings, tapered thrust roller bearings, needle roller bearings, and tapered roller bearings (Figure 10.23). Straight roller bearings provide purely radial load support in most applications; they cannot resist thrust loads. The spherical roller bearings have the advantage of accommodating some shaft misalignments in heavy-duty rolling mill and industrial gear drives. Needle bearings are in widespread usage where radial space is limited.
An Approach to Determine and Analyze the Wear Rates at Cage Pocket Contacts in Solid-Lubricated Rolling Bearings
Published in Tribology Transactions, 2019
Rahul Dahiwal, Sascha Pörsch, Markus Löwenstein, Bernd Sauer
The lifetime of solid-lubricated roller bearings depends substantially on the amount of lubricant available and usable by the bearing. There are various sources of lubrication available for the bearing. Kondo (11) lists the primary lubricant depots in his patent. For a deep-groove ball bearing, the possible lubricant sources are the inner ring and outer ring raceways or the rolling elements. Furthermore, a possible source of lubricant is associated with the cage. In this contribution, to determine the wear rates for lubricant dispensers, the following scenario of component coatings is used: Ball–raceway contact—Raceways are made of steel and are uncoated and balls are silver coated (Ag–steel contact).Ball–cage pocket contact—Cage pockets are made with PI with 15% endowed MoS2 and balls are silver coated (Ag–PI contact).
Robust design of ball bearings for an improved performance using genetic algorithm
Published in International Journal for Computational Methods in Engineering Science and Mechanics, 2021
Shashikant Kumar Verma, Rajiv Tiwari
Rolling bearings are the bearings used to carry or transmit heavy and fluctuating loads. These are used for the radial and axial loads and a combination of both. A rolling bearing’s geometry consists of rolling elements such as balls or rollers placed in between the two rings (inner ring and outer ring). A cage is also mounted between the rings to guide the rolling elements and to maintain a proper annular space between them. To carry load and permit constrained motion, the rolling contact between the rolling elements and raceways are utilized. Due to its low friction characteristics between rolling elements and raceways, these are also termed as anti-friction bearings. Based on the geometry of rolling elements, these are of generally two types, namely the ball and roller bearings. Deep Groove Ball Bearings (DGBBs), angular contact ball bearings and thrust ball bearings come under ball bearings category. Among them, DGBBs are widely used in operations because of its simple geometry, suitable for very high speeds and robustness in operations, and it results in the requirement of less maintenance. However, they have less load carrying capacity compared to roller bearings because of the area of contact (i.e., the point contact for no load condition) between the balls and races are very small, causes the development of very high magnitude of stresses. DGBBs are used in many applications, like in the turbomachinery, agriculture machinery, internal combustion engines, household electrical appliances, instruments, and meters. Therefore, it is very important for DGBBs to have a long fatigue life for an excellent performance, which motivates the designers to use different methods that optimizes the bearing’s performance [1, 2].
Dynamic analysis and frequency response of cylindrical roller bearing of an airflow root blower
Published in Cogent Engineering, 2022
Themba Mashiyane, Dawood Desai, Lagouge Tartibu
The roller bearings used in machinery come in different types such as cylindrical roller bearing, spherical roller bearing, tapered roller bearing, thrust bearing, etc. An airflow root blowers being one of such machines that operate in a compression range of 1.1–1.2 (Verma, 2014) and are used to discharge compressed air/demineralized water into a mechanical system at a steady flow rate, depending on the system requirement, it uses a cylindrical roller because the bearing has a high load-bearing capacity, and it is capable of operating efficiently under moderate speed and heavy-duty applications (Sehgal et al., 2000; Upadhyay et al., 2013; Sharma et al., 2014, 2015).