Analysis of Friction Torque Characteristics of a Novel Ball–Roller Composite Turntable Bearing

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Article

Analysis of Friction Torque Characteristics of a Novel Ball-Roller Composite Turntable Bearing

Heng Tian, Weimang Li, Xiuhua Shao, Zhanli Zhang and Wenhu Zhang

 

The manuscript presents a theoretical study coupled with experimental research on a novel ball-roller composite turntable bearing. It is a static approach under imposed stiffness conditions. The problem addressed is challenging because it is a pioneering multi-parametric analysis.

However, by purpose and objectives, the work aims to obtain a primary static model, as a preliminary element, useful for the subsequent development of an advanced model. For these reasons, I appreciate that the work is well structured and formulated.

Reviewer’s remarks

1. However, I would recommend detailing the algorithms applied for calculating the friction torque involved and describing the software applications used.
2. It is not clear how the values ​​of the parameters studied, which influence the friction torque, were modelled and incremented.
3. Also, it is appropriate to carefully discuss the combined effect of all parameters, acting simultaneously, on the kinematics of the assembly and the friction torque.
4. A comparative analysis of the new proposed model, in relation to known bearings, would be welcome, to demonstrate that, indeed, the new bearing model operates more efficiently, with better efficiency.

Finally, I appreciate that the manuscript can be considered for publication, after minor revision.

 

Comments on the Quality of English Language

In general, the text is clear and easy to understand. Of course, additional proofreading of the English expression is advisable

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors propose a new turntable bearing design combining balls with rollers in one bearing. The aim is to create a bearing design, which integrates the high stiffness of roller elements and low friction properties of balls. To fill the theoretic gap, the authors present a new calculation model.

The authors could show that the main friction is generated by the rollers, which is not a novel finding. By adjusting the clearance of the axial rollers the friction could be reduced significantly. They could also show that the combination of rollers and balls has the predicted effects on friction and load distribution. The aberration between calculation and experimantal results could also be explained and possible countermeasures have been shown.

In general, the submission is from scientific sound and provides several improvements in bearing design. Nevertheless, some points have to be addressed.

1. A general section with fundamentals is missing. The authors list the state of research regarding bearings calculations, but do not focus on the theoretical background which is necessary for their calculations and assumptions. Providing the fundamentals of bearing kinematics and load distribution would help to generate a better understanding of their calcultions and assumptions. Therefore, the authors have to provide an extra section for this.
2. In line 157 - 160, the authors list some assumptions. What are the reasons and basics for this assumptions. How do the authors come to them?
3. In line 176 - 178, the authors write about the slice method. What are the fundamentals of the slice method? Who invented it? This information can be provided in a fundamentals section
4. For most equations in section 2, it is not clear whether the authors invented them by themselves or if they are taken from literature. For example, equation (3) can be found in Dahlke 1994. Therefore, I recommend that the authors have to check the references of the equations and provide the missing ones. 
5. Line 250 - 254: This is not clear to me. The authors should provide the equations for the calculation of the displacements and the deflection angle.

After addressing the listed issues, the article can be published. Therefore, I recommend a major revision due to the fact of the missing fundamentals section. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have responded appropriately to all the reviewer's comments, so that the manuscript has been substantially improved. Also, the English text has been carefully checked and is acceptable and easy to understand. Finally, I consider that the manuscript can be considered for publication in its current form.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors addressed the feedback completly. Therefore, I recommend to accept the submission in present form.