A novel planetary thread roller bearing: Design and analysis of load characteristic

2020 ◽  
pp. 1-7
Author(s):  
Shicheng Zheng ◽  
Yongling Fu ◽  
Deyi Wang ◽  
Junlin Pan ◽  
Linjie Li ◽  
...  

Abstract A novel planetary thread roller bearing (PTRB) was proposed in this paper based on Herz theory combined with multiple principles (e.g. equivalent steel ball, multi-point meshing and power dividing). A significant improvement in load-carrying capacity, comparing the current bearing, was achieved and thus providing a new option for the advanced equipment with high thrust-to-weight ratio requirement. The newly proposed PTRB exhibited a 83 % increase in dynamic axial load rating while a comparable static axial load rating comparing with the thrust ball bearing with a comparable size. In addition, the relationship between friction torque and bearing rotating speed, contact point number and axial load was discussed. It was found that, given a proper installation space, increasing the thread roller number could not only significantly improve the axial load rating of PTRB, but also reduce the friction torque. Furthermore, the working efficiency of the new PTRB was constantly higher than 97 %. A self-degradation operation was achieved by the system when some thread rollers were stuck, which improved the system fault tolerance. Finally, friction torque tests were performed on the self-developed test instrument. The results showed a good agreement with the theoretical analysis.

1973 ◽  
Vol 187 (1) ◽  
pp. 763-770 ◽  
Author(s):  
C. M. Taylor

Normally cylindrical roller bearings are employed to transmit purely radial loads. However, depending upon the configuration of lips or flanges on the rings, it is sometimes possible to carry an axial load. In certain applications, an axial load capability is essential. A significant feature in determining the performance of a cylindrical roller bearing under axial loading is the lubrication conditions existing between the lips and rolling elements. The paper describes a study of such conditions. The long-term aim of the work is to provide a basis for the design of cylindrical roller bearings to carry axial loads.


1973 ◽  
Vol 187 (1) ◽  
pp. 763-770
Author(s):  
C. M. Taylor

Normally cylindrical roller bearings are employed to transmit purely radial loads. However, depending upon the configuration of lips or flanges on the rings, it is sometimes possible to carry an axial load. In certain applications, an axial load capability is essential. A significant feature in determining the performance of a cylindrical roller bearing under axial loading is the lubrication conditions existing between the lips and rolling elements. The paper describes a study of such conditions. The long-term aim of the work is to provide a basis for the design of cylindrical roller bearings to carry axial loads.


Structures ◽  
2021 ◽  
Vol 31 ◽  
pp. 590-601
Author(s):  
Hamed Rahman Shokrgozar ◽  
Vahid Akrami ◽  
Tayebeh Jafari Ma'af ◽  
Naseraldin Shahbazi

Author(s):  
Bugra Ertas

Abstract The following paper presents a new type of gas lubricated thrust bearing fabricated using additive manufacturing or direct metal laser melting (DMLM). The motivation for the new bearing concept is derived from the need for highly efficient supercritical carbon dioxide turbomachinery in the mega-watt power range. The paper provides a review of existing gas thrust bearing technologies, outlines the need for the new DMLM concept, and discusses proof of concept testing results. The new concept combines hydrostatic pressurization with individual flexibly mounted pads using hermetic squeeze film dampers in the bearing-pad support. Proof-of-concept testing in air for a 6.8" (173mm) outer diameter thrust bearing was performed; with loads up to 1,500 lbs (6.67kN) and a rotating speed of 10krpm (91 m/s tip speed). The experiments were performed with a bent shaft resulting in thrust runner axial vibration magnitudes of 2.9mils (74microns) p-p and dynamic thrust loads of 270 lbs (1.2kN) p-p. In addition, force deflection characteristics of the bearing system are presented for an inlet hydrostatic pressure of 380psi (2.62MPa). Results at 10krpm show that the pad support architecture was able to sustain high levels of dynamic misalignment equaling 6 times the nominal film clearance while demonstrating a unit load carrying capacity of 55psi (0.34Mpa). Gas-film force-deflection tests portrayed nonlinear behavior like a hardening spring, while the pad support stiffness was measured to be linear and independent of film thickness.


2009 ◽  
Vol 68 ◽  
pp. 167-174 ◽  
Author(s):  
Jerry Wong ◽  
Patricia del C. Zambrano ◽  
Martha Patrizia Guerrero-Mata ◽  
Victor Mucino ◽  
Rafael Colás

A series of linear and spot stir welding friction tests were carried out on aluminum samples of 1 mm in thickness and area of 100 mm x 27 mm. The tool rotating speed was varied from 2000 to 4000 RPM and the feeding rate from 45 to 67.8 mm/min. The temperature distribution during welding was measured by thermocouples inserted within the aluminum strips. The microstructure of the welded nuggets and the HAZ were analyzed by optical and scanning electron microscopy. Some samples were tested intension to measure the load carrying capacity of the welded bead. Preliminary analyses indicate that the temperature at the heat affected zone increases with the rotating speed.


2013 ◽  
Vol 312 ◽  
pp. 25-28
Author(s):  
Ji Mei Wu ◽  
Yan Chen ◽  
Bo Gao ◽  
Tuan Yong Yi

By means of considering improved Lundberg-Palmgren (L-P) fatigue life theory and rollers and other comprehensive factors, a model of fatigue life is setup for eccentric double row cylindrical roller bearing under rotation. On this basis, the calculation flow chart is given and the fatigue life is calculated. Then come to the conclusions that the fatigue life of bearing is influenced by radial load, rotating speed, radial clearance.


2021 ◽  
Vol 895 ◽  
pp. 97-109
Author(s):  
Mustafa Mazin Ghazi ◽  
Ahmad Jabbar Hussain Alshimmeri

Castellated columns are structural members that are created by breaking a rolled column along the center-line by flame after that rejoining the equivalent halves by welding such that for better structural strength against axial loading, the total column depth is increased by around 50 percent. The implementation of these institutional members will also contribute to significant economies of material value. The main objectives of this study are to study the enhancement of the load-carrying capacity of castellated columns with encasement of the columns by Reactive Powder Concrete (RPC) and lacing reinforcement, and serviceability of the confined castellated columns. The Castellated columns with RPC and Lacing Reinforcement improve compactness and local buckling (web and flange local buckling), as a result of steel section encasement. This study presents axial load test results for four specimens Castellated columns section encasement by Reactive powder concrete (RPC) with laced reinforcement. The encasement consists of, flanges unstiffened element height was filled with RPC for each side and laced reinforced which are used inclined continuous reinforcement of two layers on each side o0f the web of the castellated column. The inclination angle of lacing reinforcement concerning the longitudinal axis is 45o. Four specimens with four different configurations will be prepared and tested under axial load at columns. The first group was the control group (CSC1) Unconfined castellated steel column, the second group was consists of Castellated columns (web and flange) confined with 17mm of (RPC), welded web, and 6mm laced reinforcement (CSC3). While group three (CSC4) consists of a Castellated steel column same as the sample (CSC3), but without using welding between two parts of the castellated steel column. Groups four and five consist of a Castellated steel column same as sample (CSC4) encased partially with reactive powder concrete (25.5 mm) (CSC5) and full encased flange with reactive powder concrete (34mm) mm (CSC6), respectively. The tested specimens' results show that an increase in the strength of the column competitive with increasing the encased reactive powder concrete thickness. And the best sample was sample CSC6 with (34mm) mm in experimental and ABAQUS results.


Author(s):  
Ehab El-Salakawy ◽  
Fangxin Ye ◽  
Yasser Mostafa Selmy

Composite materials like glass fiber-reinforced polymer (GFRP) is becoming widely acceptable to be used as a reinforcing material due to its high ultimate tensile strength-to-weight ratio and excellent resistance to corrosion. However, the seismic behavior of GFRP-reinforced concrete columns has not been fully investigated yet. This paper presents the results of a numerical analysis of full-size GFRP-RC rectangular columns under cyclic loading. The simulated column depicts the lower part of a building column between the foundation and the point of contra-flexure at the mid-height of the column. GFRP reinforcement properties and concrete modeling based on fracture energy have been incorporated in the numerical model. Experimental validation has been used to examine the accuracy of the constructed finite element models (FEMs) using a commercially available software. The validated FEM was used to perform a parametric study, considering several concrete strength values and axial load levels, to study its influence on the performance of the GFRP-reinforced concrete columns under cyclic loading. It was concluded that the hysteretic dissipation capacity deteriorates under high axial load level due to severe softening of the concrete. The FE results showed a substantial improvement of the lateral load-carrying capacities by increasing concrete compressive strength.


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