Research on Lubrication Characteristics of Cage-Free Ball Bearing with Local Functional Slot
Round 1
Reviewer 1 Report
This research has found that the lubrication effect of cage free ball bearings with reduced raceways mainly depends on the thickness of the oil film between the rolling element and the conventional raceway as well as the reduced raceway, but further investigation can still be carried out in the following aspects.
1. The amount of lubricating oil required for a cage free ball bearing with a reduced raceway.
2. The influence of the depth of the raceway on the overall lubrication effect of the cage free ball bearing with reduced raceway.
3. The very latest references about lubrication effect (e.g., Acta Materialia 232 (2022) 117934; Tribology International 181 (2023) 108295) are lacking, which may be helpful for introduction and/or discussion.
4. The effect of different speed conditions on the overall lubrication effect of cage free ball bearings with reduced raceways.
Author Response
List of Responses
Dear Editors and Reviewers:
Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Research on lubrication characteristics of cage free ball bearing with local functional slot” (ID: lubricants-2316632). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:
Responds to the reviewer’s comments:
Reviewer #1:
- Response to comment: The amount of lubricating oil required for a cage free ball bearing with a reduced raceway.
Response: Thank you for your suggestion. We have added the additional research in the main text and highlighted it in red.
- Response to comment: The influence of the depth of the raceway on the overall lubrication effect of the cage free ball bearing with reduced raceway.
Response: Thank you for your suggestion. We have added the additional research in the main text and highlighted it in red.
- Response to comment: The very latest references about lubrication effect (e.g., Acta Materialia 232 (2022) 117934; Tribology International 181 (2023) 108295) are lacking, which may be helpful for introduction and/or discussion.
Response: Thank you for your suggestion, which is very helpful for our research.
- Response to comment: The effect of different speed conditions on the overall lubrication effect of cage free ball bearings with reduced raceways.
Response: Thank you for your suggestion. This is very helpful for our research. We have included theoretical and experimental studies on the overall lubrication of functional groove ball bearings without cages under different speed conditions in the main text. The added parts have been highlighted in red in the main text.
We appreciate for Editors/Reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions.
Yours sincerely,
Corresponding author:
Name: Yuan Zhang
E-mail:[email protected]
Reviewer 2 Report
Please finish or rearrange the sentence in the line 575 ('by analyzing the oil film flow rate, it is concluded that the oil film flow rate in the elliptical contact ... (?)'). Keep up with the good work...
Author Response
List of Responses
Dear Editors and Reviewers:
Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Research on lubrication characteristics of cage free ball bearing with local functional slot” (ID: lubricants-2316632). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:
Responds to the reviewer’s comments:
Reviewer #2:
- Response to comment: Please finish or rearrange the sentence in the line 575 ('by analyzing the oil film flow rate, it is concluded that the oil film flow rate in the elliptical contact ... (?)'). Keep up with the good work.
Response: Thank you for your feedback. We have revised the conclusions involved and highlighted them in red in the text.
We appreciate for Editors/Reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions.
Yours sincerely,
Corresponding author:
Name: Yuan Zhang
E-mail:[email protected]
Reviewer 3 Report
The authors studied lubrication behavior of rolling ball bearings
The main point of the paper is describing lubrication behavior with functional groove on the bearing raceway.
However there are some critical points needed confirm:
1. The authors model the contact between ball and functional groove by using equivalent radius. Then it doesn't reflect real contact between ball and race. Original functional groove contact with the ball by 2-point contact but its was modeled with single point contact.
2. There is no model verification.
Author Response
List of Responses
Dear Editors and Reviewers:
Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Research on lubrication characteristics of cage free ball bearing with local functional slot” (ID: lubricants-2316632). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:
Responds to the reviewer’s comments:
Reviewer #3:
- Response to comment: The authors model the contact between ball and functional slotby using equivalent radius. Then it doesn't reflect real contact between ball and race. Original functional slot contact with the ball by 2-point contact but its was modeled with single point contact.
Response: Thank you for your feedback. We have rewritten the second part of the article. The previous model and schematic cannot clearly reflect the dynamic relationship between the rolling element and the functional slot. The modifications have been highlighted in red in the text.
- Response to comment: There is no model verification.
Response: Thank you for your feedback. In the revised draft, we have established a model of the required lubricating oil level for a non cage bearing with functional slots based on the existing model. We have studied the impact of different rotational speed conditions on the overall lubrication effect of the bearing and added experimental verification.
We appreciate for Editors/Reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Reviewer 4 Report
The paper presents an elasto-hydrodynamic lubrication study of a special construction of ball bearing.
The paper needs some clarifications:
Must add the reference for eqs. 22 and 23.
Fig. 2: Is it a groove (interior contact with the ball) or a bump (exterior contact, as in Fig. 2)? Is this an existing construction? A geometry comparison with the “conventional raceway” should be presented. Use the same term: slot or groove or bump!
Please use the same term along the paper: reduced touch raceway or reduced-collision raceway. (recuded-collision raceway in Fig. 6)
Line 275 Please rephrase “connecting the contact point between the center of the bearing and the functional groove.”
Must define dimension parameter a and b in Table 1
Fig. 3: “Calculate the oil film thickness formula to find the oil film thickness” Please be more specific. What is the initial value of h0? Is it 0?
Table 2: What means Circumferential span angle θx, Axial span angle θz? What means thin wall” How thin?
Lines 335-346, 357-368: Please rephrase. Phrases are too long.
Fig. 4: Why is the normal force smaller for the 3000 rpm rotational speed than for the 1800 or 6000 rpm?
Fig. 6: Why tank in “tank oil film”?
Figs. 7 and 8: X axis notation is missing
Al over the paper: Measurement unit Pa instead of pa
Author Response
List of Responses
Dear Editors and Reviewers:
Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Research on lubrication characteristics of cage free ball bearing with local functional slot” (ID: lubricants-2316632). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:
Responds to the reviewer’s comments:
Reviewer #4:
- Response to comment: Must add the reference for eqs. 22 and 23..
Response: Thank you for your feedback. We have made modifications to the introduction.
- Response to comment: Fig. 2: Is it a groove (interior contact with the ball) or a bump (exterior contact, as in Fig. 2)? Is this an existing construction? A geometry comparison with the “conventional raceway” should be presented. Use the same term: slot or groove or bump!.
Response: This is our mistake and we deeply apologize for the inconvenience caused to you in reading. We have rewritten the second part of the article, redrawn the schematic diagram involved, and marked the retained schematic diagram.
- Response to comment: Please use the same term along the paper: reduced touch raceway or reduced-collision raceway. (recuded-collision raceway in Fig. 6).
Response: This is our mistake and we deeply apologize for the inconvenience caused to you in reading. We have made changes throughout the entire article and have uniformly changed it to a functional slot.
- Response to comment: Line 275 Please rephrase “connecting the contact point between the center of the bearing and the functional groove.”
Response: This is our mistake and we deeply apologize for any inconvenience caused to your reading. We have made modifications to the entire paragraph and highlighted it in red in the text.
- Response to comment: Must define dimension parameter a and b in Table 1.
Response: We have added explanations for a and b in Table 1, and added the parameters involved in the explanation after Table 1.
- Response to comment: Fig. 3: “Calculate the oil film thickness formula to find the oil film thickness” Please be more specific. What is the initial value of h0? Is it 0?.
Response: In the revised manuscript, we have re established the oil volume model of the functional slot in the second part to highlight the formula for oil film thickness in the connected third part. The initial oil film thickness is related to the structural parameters of the functional slot, which is mentioned in the rewritten second chapter. Additionally, the revised manuscript has added an analysis and verification of the relationship between oil film thickness, initial oil film thickness, and various parameters.
- Response to comment: Table 2: What means Circumferential span angle θx, Axial span angle θz? What means thin wall” How thin?.
Response: This is our mistake and we deeply apologize for the reading inconvenience caused to you. In the second part of the revised manuscript, we explained the structural parameters of the functional slot more clearly and modified the header of Table 2.
- Response to comment: Lines 335-346, 357-368: Please rephrase. Phrases are too long..
Response: This is our mistake and we deeply apologize for the inconvenience caused to your reading. We have rewritten two paragraphs of the revised manuscript and highlighted them in red.
- Response to comment: Fig. 4: Why is the normal force smaller for the 3000 rpm rotational speed than for the 1800 or 6000 rpm?.
Response: The normal force at 3000 rpm is smaller than 1800rpm because at 1800rpm, the rolling element has a smaller linear velocity, and the combined action of gravity and oil film friction causes the rolling element to move tightly against the functional slot. The reason why 6000rpm is larger than 3000rpm is due to centrifugal force. In the revised manuscript, an analysis of the relationship between speed and oil film thickness has been added, indirectly explaining this issue. Thank you again for your valuable suggestion.
- Response to comment: Why tank in “tank oil film”?.
Response: We made modifications in the revised manuscript and marked it in red.
- Response to comment: Figs. 7 and 8: X axis notation is missing.
Response: We made modifications in the revised manuscript and marked it in red.
- Response to comment: Al over the paper: Measurement unit Pa instead of pa.
Response: We made modifications in the revised manuscript and marked it in red.
We appreciate for Editors/Reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions.
Yours sincerely,
Corresponding author:
Name: Yuan Zhang
E-mail:[email protected]
Round 2
Reviewer 3 Report
The authors have revised the manuscript by adding experimental verification.
That can be a point to consider for publication.
Reviewer 4 Report
Agree with all revisions.
