A Comparative Analysis of Multi-Scale and Rayleigh Approaches in Capturing Eigenfrequencies and Mode Shape Evaluation in Planetary Gear Transmission Systems of Medium and Heavy Trucks

Round 1

Reviewer 1 Report

Planetary geas, as a specialized type of gear transmission, possess certain advantages and disadvantages compared to conventional gear transmissions. The main advantages include compact construction, high transmission ratios, high efficiency, uniform distribution of loads, reduced mass compared to conventional transmissions efficient utilization of the internal space of the transmission, and more.. The primary disadvantages of planetary gears include the need for high precision during manufacturing and assembly, and dynamic imbalance, especially in cases with a large number of satellites. Emphasize their advantages and disadvantages (https://doi.org/10.18485/aeletters.2022.7.1.5 , https://doi.org/10.1115/1.4039337 ).

- Specify the applications where planetary gears are used.

- Demonstrate the main contribution of the paper and why this paper should be published. What is the main idea of the paper?

- Why was this specific planetary gear chosen?

- What is its designation?

- Based on what criteria were exactly 4 satellites chosen in the planetary gear system? Can this dynamic model be applied in the case of a different number of satellites (N=5, N=6...)?

- Standardize notations throughout the text (multi-scale, multi scale...).

- When using an abbreviation for the first time, provide a description of that abbreviation.

- Standardize labels in the entire text, equations, and figures. Use the same font and labels for quantities.

- Axes are missing on the figures.

- Write unit labels in accordance with the standard and the journal's instructions (Nm instead of N.m…).

- Standardize the text on the figures and below the figures. For example, Figure 4 (speed-velocity).

- Provide references for all terms used in the paper.

- The paper lacks a discussion of the results. Compare these results with the results of other researchers.

- Expand the conclusion based on the introduced changes.

Author Response

Dear Reviewers,

The authors extend their heartfelt gratitude for the invaluable feedback and insightful comments provided on our manuscript titled "Dynamic Modelling and Modal Analysis of Planetary Gear Transmission Systems in Medium and Heavy Duty Diesel Trucks: A Comparative Study of Multi-scale and Rayleigh Approaches." Your thoughtful evaluation and constructive suggestions have immensely contributed to refining the depth and quality of our work.

In response to your comprehensive review, the authors have precisely analysed each comment and critique. response letter aim revisions and our strategy for addressing the highlighted concerns, incorporating necessary revisions, and elucidating our enhancements to ensure the manuscript's robustness and scholarly contribution.

We have organized our response in a systematic manner, addressing each comment sequentially. For ease of reference, we have aligned our responses with the corresponding sections, figures, tables, and equations within the manuscript. Each suggestion or query has been carefully considered, leading to precise modifications, clarifications, or expansions where deemed necessary.

              This manuscript's significant contributions are as follows:

1. The title of the manuscript has been changed to “Comparative Analysis of Multi-scale and Rayleigh Approaches in Capturing Eigen Frequencies and Mode Shape Evaluation in Planetary Gear Transmission Systems of Medium and Heavy Trucks” where it captures the essence of the manuscript more effectively than the previous title.
2. The transmission error section has been eliminated as the authors find it unnecessary to emphasize this aspect. The primary focus is on conducting a comparative analysis between the Rayleigh energy approach and the multi-scale approach, aiming to quantify differences between these methodologies instead of delving into the transmission error. As an alternative, the authors explored the properties of the Rayleigh quotient.
3. The preceding lumped parameter model equations have been replaced with the Lagrange equations following Singiresu [1]. These equations illustrate both the kinetic energy and elastic potential energy functions. This substitution serves also to reduce the number of equations, thereby streamlining the manuscript.
4. The figures' quality has been enhanced to ensure better readability and optimal printing standards.
5. The manuscript received careful proofreading by an English language expert to address the errors and improve linguistic clarity.

We are committed to delivering an improved manuscript that encompasses both the essence of our original research and the necessary refinements to meet the standards of academic excellence and scientific rigor expected by the Machines esteemed journal.

Thank you once again for your invaluable time and efforts in evaluating our work. We are eager to present the revised manuscript, incorporating your invaluable inputs, and contributing meaningfully to the scientific discourse in our field.

Sincerely,

Mahmoud Mabrouk

Beijing Institute of Technology

1. Singiresu, S.R., Mechanical vibrations. 1995: Addison Wesley Boston, MA.
   
   

Please see the attachment for detailed point-to-point response.

Author Response File: Author Response.pdf

Reviewer 2 Report

-       Generally, figures are of low quality, especially those schematically representing planetary gearboxes. It would be very difficult to read them after printing the article.

-       Figure 1 shows a gearbox that doesn't work. Of course, it is a schematic representation, but it should accurately depict planetary gears and carriers. For example, at stage 3, how are planet carriers connected to the planetary gear? In the shown way, planets can't rotate. Additionally, there are no ring gears in stages 2 and 3. In these stages, the gearbox should have the possibility to engage these rings and facilitate rotation, but in the figure, such a possibility is not shown. There is no distinction between important and unimportant lines; all lines have the same thickness.

-       The article lacks a description of how many speeds this gearbox provides.

-       In line 143, what is the meaning of 'TE'? Does it stand for total error? If yes, please explicitly show that.

-       In line 167, it mentions N.m (there is no such unit in SI). It should be N m.

-       Figure 5 is challenging to read. I believe it would be much more readable in a different format.

-       In Figure 6, specifically in the Gear mode shape area, it is very inconvenient to display all designations on the x-axis in this manner. The graphical elements of the figure, such as lines, have the same thickness. I believe that vectors should be represented differently than shown in this figure.

-       Figures 7, 8, 9, and 10 exhibit the same issue as Figure 6.

-       Figures 12, 13, 14, 15, and 16 face the same challenges as Figure 5.

I think that the English language should be sent to someone who is better in English than the authors for proofreading. I noticed a couple of minor mistakes.

Author Response

Dear Reviewers,

The authors extend their heartfelt gratitude for the invaluable feedback and insightful comments provided on our manuscript titled "Dynamic Modelling and Modal Analysis of Planetary Gear Transmission Systems in Medium and Heavy Duty Diesel Trucks: A Comparative Study of Multi-scale and Rayleigh Approaches." Your thoughtful evaluation and constructive suggestions have immensely contributed to refining the depth and quality of our work.

In response to your comprehensive review, the authors have precisely analysed each comment and critique. response letter aim revisions and our strategy for addressing the highlighted concerns, incorporating necessary revisions, and elucidating our enhancements to ensure the manuscript's robustness and scholarly contribution.

We have organized our response in a systematic manner, addressing each comment sequentially. For ease of reference, we have aligned our responses with the corresponding sections, figures, tables, and equations within the manuscript. Each suggestion or query has been carefully considered, leading to precise modifications, clarifications, or expansions where deemed necessary.

This manuscript's significant contributions are as follows:

1. The title of the manuscript has been changed to “Comparative Analysis of Multi-scale and Rayleigh Approaches in Capturing Eigen Frequencies and Mode Shape Evaluation in Planetary Gear Transmission Systems of Medium and Heavy Trucks” where it captures the essence of the manuscript more effectively than the previous title.
2. The transmission error section has been eliminated as the authors find it unnecessary to emphasize this aspect. The primary focus is on conducting a comparative analysis between the Rayleigh energy approach and the multi-scale approach, aiming to quantify differences between these methodologies instead of delving into the transmission error. As an alternative, the authors explored the properties of the Rayleigh quotient.
3. The preceding lumped parameter model equations have been replaced with the Lagrange equations following Singiresu [1]. These equations illustrate both the kinetic energy and elastic potential energy functions. This substitution serves also to reduce the number of equations, thereby streamlining the manuscript.
4. The figures' quality has been enhanced to ensure better readability and optimal printing standards.
5. The manuscript received careful proofreading by an English language expert to address the errors and improve linguistic clarity.

We are committed to delivering an improved manuscript that encompasses both the essence of our original research and the necessary refinements to meet the standards of academic excellence and scientific rigor expected by the Machines esteemed journal.

Thank you once again for your invaluable time and efforts in evaluating our work. We are eager to present the revised manuscript, incorporating your invaluable inputs, and contributing meaningfully to the scientific discourse in our field.

Sincerely,

Mahmoud Mabrouk

Beijing Institute of Technology

1. Singiresu, S.R., Mechanical vibrations. 1995: Addison Wesley Boston, MA.

Please see the attachment for point-to-point response.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Accept in present form

Reviewer 2 Report

Dear Authors, I have noticed that you have made a lot of changes according to my suggestions. However, I still found the same mistakes as before (e.g., figures from 9 to 14 are the same as before). I believe these are not crucial for readability, and you don't have to change them. I think the article is ready for publishing.

Best regards,