Calculation of scuffing load capacity of cylindrical, bevel and hypoid gears

2015 ◽  
Keyword(s):  
2011 ◽  
Vol 86 ◽  
pp. 237-242 ◽  
Author(s):  
Bernd Robert Höhn ◽  
Karsten Stahl ◽  
Christian Wirth

At the FZG (Gear Research Centre, Munich, Germany) a research project was carried out to analyze the influence of the hypoid offset on the load capacity of bevel gears by systematic theoretical and experimental investigations. For the experimental investigations two types of bevel gears were designed, one for the pitting tests and one for the tooth root tests. The results of the tooth root tests showed as expected an increasing load capacity with higher offsets. In contrast the pitting tests showed an increasing, but after reaching a maximum, a decreasing load capacity with higher offsets. Regarding the test results a new calculation method was developed that is based on a loaded tooth contact analysis (LTCA). The method is able to consider the local stresses on the flank and in the tooth root. The local strength values are derived out of the standard ISO 6336 for the calculation of helical gears. For bending the local geometry of the tooth root is considered to adopt the strength values of helical gears to bevel and hypoid gears. As a result the local safety factors might be calculated along the face width of pinion and wheel. For pitting the local sliding conditions are taken into account in order to appraise the local lubrication conditions as well as the risk of crack initiations due to shear stresses and higher contact temperatures. The recalculation of the test showed for both types of failure a good correlation between the test results and the calculated values.


Author(s):  
E Conrado ◽  
B-R Höhn ◽  
K Michaelis ◽  
M Klein

In industrial or automotive dip lubricated gear drives, low oil levels may be used due to different design requirements or constraints. A variation of the sump oil level affects different working conditions of gears, such as the power loss, the heat generation, and the load-carrying capacity with respect to different types of damage. In particular, reduced oil levels decrease the scuffing load capacity of gears because of high bulk temperatures and reduced oil quantity in the gear mesh. Investigations were made in a back-to-back hypoid gear test rig to evaluate the influence of the bath oil level on the scuffing load-carrying capacity of dip lubricated hypoid gears.


Author(s):  
Dennis Flanagan ◽  
Alessandro Fisher BS ◽  
Carmen Ciardiello ◽  
Vito Moreno ◽  
Alen Uvalic ◽  
...  

When planning an implant supported restoration the dentist is faced with the surgical and prosthetic technical issues as well as the patient’s expectations. Many patients wish an immediate solution to an edentulous condition. This is especially may be true in the esthetic zone. The extent of the zone is determined by the patient. The dentist may consider when it is feasible to load the supporting implants with definitive or provisional prosthetics. For the work herein, consideration of many parameters were theoretically assessed for inclusion: bone density, cortical thickness, seating torque, parafunction, bite load capacity, number of implants under load, implant/crown ratio, implant diameter and length. After assessment, the most influential parameters were selected. An iteration, using patient age, implant diameter, bite load capacity and cortical thickness, is now presented to aid the implant dentist in determining the feasibility for immediate functional loading of a just placed dental implant in a healed site. Extensive testing is required to develop this concept. According to this iteration, most immediate functional loaded implants would fail. A future refined and definitive formula may enable the clinician to safely immediately functional load an implant with a definitive prosthesis.


2018 ◽  
Vol 9 (5) ◽  
pp. 174
Author(s):  
Agus Maryoto ◽  
Han Ay Lie ◽  
Nanang Gunawan Wariyatno

2020 ◽  
Vol 40 (11) ◽  
pp. 905-907
Author(s):  
V. I. Korotkin ◽  
E. M. Kolosova ◽  
N. P. Onishkov
Keyword(s):  

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