Lubrication Modeling of the Reciprocating Piston with High Lateral Load and Various Conditions in a Swash Plate-Type Piston Pump
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsDear authors：
I am honored to review your article，the following comments are made for discussion.
(1)In this paper, a boundary lubrication model considering the elastic deformation is established, and the author is asked to explain the innovation or difference from the existing lubrication model. In addition, whether there are experiments or reference databases to verify the reliability and accuracy of the model.
(2)Authors should explain the blank graph of g and i in Figure 8, and explain the reason and rationality of the maximum contact stress of 2000 MPa in Figure h.The corresponding problems suggest that the author carefully check.
(3)In the conclusion, it is suggested that the author add the specific gravity analysis of the influence of each working condition on the lubrication characteristics and power loss characteristics.
Comments on the Quality of English LanguageMinor editing of English language required
Author Response
Dear Editor and Reviewer
We would like to thank the reviewers for their thorough reviews and useful comments and insights. Changes suggested by the reviewers have been incorporated in the manuscript. I hope that the referees will find them satisfactory. If there are further changes to be made, we will be happy to comply. We prepared sincere responses to your comments as a file.
Sincerely yours,
Jung-Hun Shin, Sung-Ho Hong
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsComments to the Author’s
Authors discussed an interesting paper on tribological analysis of piston pump by developing boundary lubrication model. The manuscript is well written but presented very badly. Authors are requested to do serious change in the manuscript according to several comments suggested for further improvement.
· Please put Figure 1 and 2 in Section 2 and defined all the symbols in text on their first appearance. Symbols containing ‘F’ is not defined at all in whole manuscript. It is not clear what is lateral force in which direction.
· Update Nomenclature list also. It is incomplete.
· Please define each parameters on their first appearance. We cannot think about addressing model without clarifying parameters. Do it for each equations (Eq. 1 to 25). Authors can not put everything in nomenclature. To understand the model, first parameter are needed to be clarified.
· Noting is mentioned on How Eq. 9 was solved. Which method was used ?. Was load convergence performed ?. What convergence criteria was used ?. What types of boundary conditions was employed (Dirichlet or Neuman). Please write a separate on solving method of Eq. 9.
· Figure 6 should be below the Sec. 3.2. It is always recommended that any figure should be placed below to the corresponding Section.
· What symbol was used to denote the Coulomb friction?.
· Fig. 7 is also placed above to the Sec. 2.3. Is this appropriate writing style?. I did not see anything like this before.
See this paper which is also published in lubricants: https://doi.org/10.3390/lubricants10010012
· Please strictly follow the guidelines of Lubricants Journal
· The same is true for Figures 8, 9, 10. Please changed all figures position. This way it is very hard to understand the results and discussion part.
· Figure 10, how can higher speed make negative effect on power loss, and friction ?. Explain this opposite trend.
· The develop model is not validated from published result.
· Figure 11, what is operating pressure. Is this total equivalent load applied on piston ?.
Author Response
Dear Editor and Reviewer
We would like to thank the reviewers for their thorough reviews and useful comments and insights. Changes suggested by the reviewers have been incorporated in the manuscript. I hope that the referees will find them satisfactory. If there are further changes to be made, we will be happy to comply. We prepared sincere responses to your comments as a file.
Sincerely yours,
Jung-Hun Shin, Sung-Ho Hong
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe paper can be accepted, but it is necessary to carry out certain refinements in order to improve the quality of the work and its application for subsequent tests.
Fluid-structure interaction between piston and cylinder is explained very well, concisely but completely.
It is needed to note inside the introduction part that the piston with piston mechanism is the main part inside reciprocating machines, not only for hydraulic piston machines.
As an example, inside IC engines, the piston mechanism is mainly, but usually obligatory, eccentrically mounted with regard to the cylinder vertical axis. You can compare this reason with your situation with the hydraulic pump example. This is very important regarding the tribological situation between the piston and cylinder in terms of friction and wear.
The piston bowl in the piston head has an influence on the front pressure and lateral forces between the piston and cylinder. More detailed information can be seen inside the work: https://doi.org/10.17559/TV-20211220232130
Inside the paper, you are analyzing the lubrication between the cylinder and piston directly without piston rings, and this is a specific situation. It is also very important to explain the cylinder mounting position. Is it horizontally mounted or vertical, etc.? This is because of the tribology between sliding surfaces. If the mounting position is horizontal, it is very important to consider the forces regarding piston mass only on one cylinder side.
From that side, it is very important to use pistons with lower mass, made of aluminum. Wear and friction inside cylinders and pistons made of aluminum alloy in that situation can be resolved with reinforcements, for example, inside reciprocating air compressors. For this, you can study and cite the following literature: https://doi.org/10.18485/aeletters.2023.8.4.3
- Expand the introduction or other chapters with pappers from this field.
- In the concluding remarks, it is necessary to unequivocally state whether the obtained results confirmed the expectations and assumptions, i.e. whether there were deviations or completely opposite results from the expected ones.
- The analysis with different lubrication oils is also needed if possible, but not obligatory. Please specify the oil grade and maker.
- Based on the analysis and discussion, expand the concluding considerations, especially in terms of further research in the field of application of other materials and additives, both for the basic aluminum alloy and for the layer that is applied to improve the characteristics of the basic alloy, but also in the field of application of other modern the technique of applying surface layers of materials, using lasers of different characteristics or other production and diagnostic equipment. In accordance with the current possibilities, it is necessary to comment on the expected costs and the price of the application of this technological procedure, primarily because of the possibility of its commercialization and mass application, with indications of future research in this field.
Author Response
Dear Editor and Reviewer
We would like to thank the reviewers for their thorough reviews and useful comments and insights. Changes suggested by the reviewers have been incorporated in the manuscript. I hope that the referees will find them satisfactory. If there are further changes to be made, we will be happy to comply. We prepared sincere responses to your comments as a file.
Sincerely yours,
Jung-Hun Shin, Sung-Ho Hong
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsNo comments further. Authors has addressed more or less my previous comments. I am satisfied with responses.
