Machining Accuracy Enhancement of a Machine Tool by a Cooling Channel Design for a Built-in Spindle

Round 1

Reviewer 1 Report

Comment 1:
There is no numbering in the rows and this makes it difficult for the reviewer

Comment 2:
full text alignment for '' Graduate Institute of Precision Manufacturing .....
and ''Industrial Technology Research Institute

Comment 3:
into the external heat source and the internal heat source.
=>
into the external and the internal heat source.

Comment 4:
Page numbering is not correct (2 of 4 => 2 of 24)

Comment 5:
2. Experimental Equipment Construction and Thermal Deformation Measurement
2.1. Eeperimental Equipments
It's not so good to start the sub-chapter at the bottom of the page without using text

Comment 6:
2.1. Eeperimental Equipments
=>
2.1. Experimental Equipments

Comment 7:
PAGE 4 (c) Pair path split cooling (separate cooling oil of bearing and motor) (unit: mm)
=> remove to the page 5 above the figure
PAGE 5 (c) Pair path split cooling (separate cooling oil of bearing and motor) (unit: mm)

Comment 8:
PAGE 5 (h) Trapezoidal channel type with paralleling front bearing channel (unit: mm)
=> remove to the page 6 above the figure
PAGE 6 (h) Trapezoidal channel type with paralleling front bearing channel (unit: mm)

Comment 9:
2.4. Heat Source Measurement and Calculation
=>
It's not so good to start the sub-chapter at the bottom of the page without using text

Comment 10:
The numbering of all equations (1 - 23) should be at the end of the row on the right side of the text.

Comment 11:
2.6. Governing Equations of Spindle Cooling Flow
=>
It's not so good to start the sub-chapter at the bottom of the page without using text

Comment 12:
Page 9
length [27].
=> [26] is missing. Change reference [26] with [27].
length [26].

Comment 13:
Page 9
friction sources is calculated [28] as
=>
friction sources is calculated [?? SKF REFERENCE] as

Comment 14:
Page 10
FANUC motor specification [26].
=>
FANUC motor specification [28].

Comment 15:
Page 11
Insert a figure from the simulation
by ANSYS software with the typical results

Comment 16:
Page 11
Table 2 shows a comparison
=>
Gap between text and table

Comment 17:
Page 12
Table 3 illustrates the average
=>
Gap between text and table

Comment 18:
Page 13
the deformation of the built-in spindle is 6.3 μm
=>
the deformation of the built-in spindle is 118.3 μm (difference is 6.3 μm)

Comment 19:
Page 14
Table 4
Width(P1)
=>
Width (P1)
Height(P2)
=>
Height (P2)
Oil Flow Rate
=>
Oil Flow Rate (P3)

Comment 20:
Page 14
Table 5 shows the results
=>
Gap between text and table

Comment 21:
Page 15
Table 5
P1Width
=>
Width (P1)

P2Height
=>
Height (P2)

P3 cooling oil flow (kg/sec)
=>
Cooling oil flow (P3)
(kg/sec) (as mm given in the adjacent column)

Comment 22:
Page 15
The sensitivity level of the
=>
Gap between text and table

Comment 23:
Page 15
numerical analysis software
=>
Indicate which specific software was used

Comment 24:
Page 16
Table 6. Optimal combination of cooling channel dimensions.
=>
the table title must be in the same page with the table

Comment 25:
Page 18
delete the space in the page end

Comment 26:
Page 19
delete the space in the page end

Comment 27:
Page 21
Table 9. Machining accuracy results in the machining verification.
=>
the table title must be in the same page with the table

Comment 28:
Page 22
In the practical machining
=>
Gap between text and table

Comment 29:
Page 23
B.,Fitting the Weibull
=>
B., Fitting the Weibull

Comment 30:
Page 23
http://www.hiwin.com.tw/
The site is not active

Comment 31:
Page 23
www.mikino.co.jp
The site is not active

Comment 32:
Page 24
Delete 29 and 30.

 

Author Response

Dear reviewers,

     We would like to thank you for your careful and thoughtful comments about our manuscript. We really appreciate the time and effort that have gone into your detailed comments. These comments are all valuable and very helpful for revising and improving our manuscript, as well as the important guiding significance to our researches.

Best regards

Win Jet, Luo

Author Response File: Author Response.docx

Reviewer 2 Report

The precision of machine tools is affected by many factors, the most important being the stiffness of the main spindle and the wear of the tool. The spindle is usually sustained on rolling bearings, allowing high speed and good rotational precision. Unfortunately, beside the heat generated by electrical motors, rolling bearing friction is one of the most important sources of heat generation. Excessive heat produces thermal deformations of the main spindle, directly affecting the machining precision, dimensional and surface quality of manufactured workpieces.

Considering the previously mentioned aspects, the subject of the paper is of interest. The authors proposed multiple solutions for the evacuation of the heat generated by motor and front rolling bearing of the spindle. Numerical simulations were done to find the optimal solution from various types of cooling channels. The optimization of the channel's dimensions were realized by  design of experiments (DOE) method. Experimental measurements of developed temperatures and machining precision proved the effectiveness of the proposed optimized cooling channel over the original non-optimized design.

I consider that this paper is original, being an important contribution to the field of machine tools and manufacturing. The research is well conducted and the paper is properly written. Taking into account the extensive theoretical and experimental research conducted in this paper, I propose to publish it as it is, after a minor revision of typing errors. 

Author Response

Dear reviewer,

     We would like to highly appreciate your useful comments to the manuscript. In order to meet the publication standards, the manuscript has been revised thoroughly in terms of the comment. These comments are all valuable and very helpful for revising and improving our manuscript, as well as the important guiding significance to our researches.

Best regards

Win Jet, Luo

Author Response File: Author Response.docx