General Comments

In this paper, the authors summarize the literature pertaining to rolling contact fatigue life fatigue for oscillating bearings – including many clarifications and filling of gaps. The similarities and differences and pros and cons for the various methods are highlighted, concluding in an interesting and helpful flow chart that recommends the best method(s) depending on the application conditions. This is followed by several different examples that describe the basic parameters of each application from the resulting method. This reviewer’s experience is that the variety of these methods is quite confusing, so having a succinct review of them with a few examples is helpful. The title is certainly sufficient, but I might also suggest “Review of rolling contact fatigue life calculation for oscillating bearings and application-dependent recommendations for use”. It's a bit more general, as there are 2 non-wind examples, and 2 wind examples.

Specific Technical Comments

None

Minor Clarifying Comments

Line 12: I would add “Their movements…” to indicate to the reader that the sentence is describing pitch movements, as the same language is used in the next sentence to describe yaw movements.

Line 25: I would write “An overview…is given in Section 2.”

Line 168: I believe this is an “s” missing in “…either Harris’s…”

Please see attached file. 

This paper reviews the life calculation methods in the literature for oscillating bearings failed by roller contact fatigue. The review is thorough and has sufficient details. Places that need to be improved are below:

1. Using “recommendation” in the title is misleading. Please change it to “Review of life calculation methods on rolling contact fatigue for oscillating bearing with use examples” or like
2. Page 1, line 16, please elaborate on which conditions rolling contact fatigue will occur. Similarly, what conditions wear will appear. Do authors know the likelihood of rolling contact fatigue occurrence in wind turbine applications?
3. Figure 4 and Figure 5 can put sub figures side by side to use blank space.
4. In some places, language needs to be further polished. Such as combining short paragraphs,
5. Page 14, at the end of chapter 2, please summarize and compare the various life calculation methods using tables or other forms. Please add discussions on the differences among various approaches. Table 1 is great and please expand the discussion around it.
6. Page 15, experimental validation. As discussed, appropriate experimental validation is currently lacking for the discussed life calculations methods in general. Although correct, this statement can give impressions that all the discussed calculation methods might not be reliable. I would recommend expanding this chapter by including discussions on future work – gaps in the current literature and lack of experimental validation. If experimental validation, what test needs to be performed?
7. Chapter 4.2 and 4.3 describes examples not in wind turbines, indicated otherwise in the title. These sections can be removed.
8. Will the authors consider perform experiments to validate these discussed life calculation methods in the future?