Modelling and experiment of gear hob tooth profile error for relief grinding

2021 ◽  
pp. 095440542110172
Author(s):  
Shuying Yang ◽  
Weifang Chen ◽  
Zhiqiang Wang ◽  
Yanfeng Zhou
Keyword(s):  
Prediction Model ◽  
High Speed ◽  
Tooth Profile ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Feed Speed ◽  
Machining Parameters ◽  
Profile Error ◽  
Mechanical Coupling ◽  
Axial Profile

Gear hob is an important tool that is most used in gear processing. Hob accuracy directly exerts an overwhelming influence on the quality of the processed gear. Generally, the hob tooth profile accuracy is mainly determined by relief grinding process. Studies on tooth profile errors of gear hobs caused by severe friction and cutting with the high-speed rotation of the wheel during the form grinding machining of hobs are limited. Thus, a theoretical model of the tooth profile error prediction under different machining parameters was established based on the analysis of coupling influence of high temperature and high strain rate on gear hobs in the relief grinding process. The model was completed on the basis of the dynamic explicit integral finite element method of thermo-mechanical coupling. Through the prediction model, the influence of the grinding depth ap, feed speed Vw and grinding speed Vs on the tooth profile error can be analysed. In addition, an algorithm for accurately calculate the grinding wheel axial profile by combining instantaneous envelope theory and hob normal tooth profile was proposed. The hob relief grinding experiments were carried out using the proposed grinding wheel profile algorithm. The relative error of the prediction obtained by comparing the calculation results of the prediction model with the experimental results is within 10%. Results prove the validity of the prediction model. This finding is greatly important for optimising the accuracy of hob relief grinding.

Simulation research on temperature field and stress field during rail grinding

2021 ◽  
pp. 095440972098456
Author(s):  
LM Huang ◽  
HH Ding ◽  
SY Zhang ◽  
K Zhou ◽  
J Guo ◽  
...  
Keyword(s):  
Residual Stress ◽  
Temperature Field ◽  
Rotational Speed ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Feed Speed ◽  
Grinding Wheels ◽  
Mechanical Coupling ◽  
Rail Head ◽  
Rail Grinding

The rail grinding process generates a large amount of heat, which could lead to heat damage on the ground rails. But, the whole temperature field of rail ground by the grinding train has not been explored in detail. In the present study, finite element models of a rail and grinding wheel were established to simulate the rail grinding process. The temperature field and the thermo-mechanical coupling stress during rail grinding, and the residual stress after grinding were studied. Furthermore, through simplifying grinding wheels into heat sources, the temperature field of rail ground by a whole grinding train was investigated as well. The results indicated that the grinding temperature and the residual stress increased with the grinding depth and rotational speed, but decreased with the feed speed and radius of rail head. The thermo-mechanical coupling stress increased with the radius of rail head and grinding depth, and decreased with the rotational speed and feed speed. When ground by the whole grinding train, the increase in the number of grinding wheels at the same grinding angle and adjacent angles could lead to a rise in temperature on the rail surface. The speeds of grinding train and the rail head radius also have an influence on the temperature. The optimal feed speed of the grinding train should be below 12 km/h for R300, 16 km/h for R80, and 18 km/h for R13. The results could be used to optimize the grinding parameters and grinding pattern in the field.

Modified-Roll Profile Correction for a Gear Shaping Cutter Made by the Lengthwise-Reciprocating Grinding Process

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Chin-Lung Huang ◽  
Zhang-Hua Fong
Keyword(s):  
Tooth Profile ◽  
Roll Motion ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Profile Error ◽  
Sensitivity Matrix ◽  
Profile Correction ◽  
Wheel Profile ◽  
Profile Errors ◽  
Gear Shaping

The tooth profile error of a gear shaping cutter made by the lengthwise-reciprocating grinding process (LRGP) is usually corrected by modifying the grinding wheel profile. However, such grinding wheel modification cannot eliminate the twisting profile error along the face of the shaping cutter. A kinematic modified roll motion for generating a shaping cutter is proposed to minimize such twisted profile errors even after cutter resharpening. The tooth profile errors of the work gears generated by the shaping cutter with various resharpening depths are represented as a novel topographic error map. Based on the error map and its sensitivity matrix, the roll ratio between the shaping cutter and the grinding wheel stroke is modified to reduce the twisted profile error as illustrated by the numerical examples. Combining this modified roll motion modification and the grinding wheel profile correction, the high accuracy resharpening depth of the LRGP helical shaping cutter is increased.

Study on Edge Contact Area and Surface Integrity of Workpiece in Point Grinding Process

2009 ◽  
Vol 407-408 ◽  
pp. 577-581
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Guang Qi Cai
Keyword(s):  
Surface Integrity ◽  
Contact Area ◽  
High Speed ◽  
Ground Surface ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Edge Contact ◽  
Cylindrical Grinding ◽  
Theoretic Foundations

During cylindrical grinding process, the geometric configuration and size of the edge contact area between the grinding wheel and workpiece have the heavy effects on the workpiece surface integrity. In consideration of the differences between the point grinding and the conventional high speed cylindrical grinding, the geometric and mathematic models of the edge contact area in point grinding were established. Based on the models, the numerical simulation for the edge contact area was performed. By means of the point grinding experiment, the effect mechanism of the edge contact area on the ground surface integrity was investigated. These will offer the applied theoretic foundations for optimizing the point grinding angles, depth of cut, wheel and workpiece speed, geometrical configuration and size of CBN wheel and some other grinding parameters in point grinding process.

Study on Effect of Grinding Fluid Supply Parameters on Surface Integrity in Quick-Point Grinding for Green Manufacturing

2008 ◽  
Vol 53-54 ◽  
pp. 209-214 ◽  
Author(s):  
Shi Chao Xiu ◽  
Ya Dong Gong ◽  
Guang Qi Cai
Keyword(s):  
Surface Integrity ◽  
High Speed ◽  
Point Contact ◽  
Green Manufacturing ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Fluid ◽  
Fluid Supply ◽  
High Speed Grinding ◽  
Grinding Power

In high and super-high speed grinding process, there is an airflow layer with high speed around the circle edge of the grinding wheel that hinders the grinding fluid into contact layer, namely, the air barrier effect. The speed of airflow layer is directly proportional to the square of the wheel speed. Quick-point grinding is a new type of high and super-high speed grinding process with a point contact zone and less grinding power. The edge effect of the air barrier is weakened because the thin CBN wheel is applied in the process. By the analysis of dynamic pressure and velocity distributions in the airflow layer around the wheel edge, the mathematic models of the flow and jet pressure of grinding fluid for effective supply in the process were established and the process of optimization calculation of the jet nozzle diameter for green manufacturing was also analyzed based on the thermodynamics and the technical character of quick-point grinding process. The quick-point grinding experiment for surface integrity influenced by grinding fluid supply parameters was performed.

Novel Third-Order Correction for a Helical Gear Shaping Cutter Made by a Lengthwise-Reciprocating Grinding Process

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Chin-Lung Huang ◽  
Zhang-Hua Fong ◽  
Shi-Duang Chen ◽  
Kuang-Rong Chang
Keyword(s):  
Gear Tooth ◽  
Helical Gear ◽  
Tooth Profile ◽  
Order Correction ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Third Order ◽  
Profile Correction ◽  
Profile Accuracy ◽  
Gear Shaping

Although the Isoform® lengthwise-reciprocating grinding process is considered as one of the most accurate methods for generating the tooth profile geometry of a helical gear shaping cutter, the tooth profile accuracy produced by the Isoform® with a straight cone grinding wheel is not accurate enough for high precision requirement. That is why the shaper cutter is used as a rough cutting tool for most cases. A third-order profile correction to the cone grinding wheel is proposed to increase the accuracy of the work gear profile. A novel topography is developed to schematically show the work gear tooth profile accuracy cut by a resharpened shaping cutter. The profile errors corresponding to the varied resharpening depth are shown in the topography with information of true involute form diameter and semitopping depth. The usable resharpening depth of the shaping cutter can be determined by this topography. The numerical result indicates that third-order correction reduces the profile error of the major cutter enveloping gear to submicro and extends the resharpening depth.

The Computation of Grinding Parameters for the Modified Shaper Cutter

2011 ◽  
Vol 121-126 ◽  
pp. 2701-2705
Author(s):  
Chao Huang ◽  
Guo Long Li
Keyword(s):  
Coordinate System ◽  
Relative Motion ◽  
Tooth Profile ◽  
Tooth Surface ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Parameters ◽  
The Relationship

Grinding process is regarded as the most effective way to generate the tooth profile of spur shaper cutter. However, for the purpose of generating a tip chamfer of gear, the semi-topping is always required on the tooth surface of shaper cutter, which is difficult to process by grinding wheel. This paper proposes a method to compute the profile of grinding wheel which is used to process the spur shaper cutter with a semi–topping. Firstly, translate the points on the surface of shaper cutter into auxiliary rack; Secondly, building the relationship between the coordinate system of grinding wheel and coordinate system of auxiliary rack; Lastly, the points on the surface of auxiliary rack are translated into the coordinate system of grinding wheel based on the relative motion between the grinding wheel and shaper cutter.

The Process Strategies of Mould High-Speed Machining and their Applications in the Environment of PowerMILL

2011 ◽  
Vol 188 ◽  
pp. 542-548 ◽  
Author(s):  
Jie Liu
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Feed Speed ◽  
Machining Parameters ◽  
High Speed Machining ◽  
Whole Process ◽  
Machining Strategies ◽  
Selection Of

High-speed machining requires the support of high intelligent CAM software as well as customized machining strategies and properly selected machining parameters. Only by combining the two can the advantage of high-speed machining be made full use of. Compared to ordinary NC cutting, high-speed machining has special requirements for process strategies, CAM system and tool path. A complete tool path includes approaching/retracting tool, moving tool and tool path. Based on the above principles, a mould part is successfully processed using the PowerMILL software at the high-speed machining centre of DMG-DMU40T. The maximum hardness of the mould part is HRC50. There’s a 30 degree corner in the cavity with a transition radius of 3mm. The whole process can be divided into three stages: rough, semi-finish and finish machining and each stage involves the selection of tool path, the selection of tool, the selection of cutting parameters (including spindle speed, feed speed and depth of cut), and the application of PowerMILL specific machining methods (such as Race-line machining, rest roughing, automatic trochoidal machining, 3D offset finishing and etc).

Research on the Grinding Force of the Basin-Like Grinding Wheel in Grinding Elliptical Grooves of Outer Race

2013 ◽  
Vol 823 ◽  
pp. 143-148
Author(s):  
Xiao Xue Li ◽  
Jun Ming Wang ◽  
Yu Qin Sun ◽  
Zhen Gang Gao
Keyword(s):  
High Speed ◽  
Grinding Force ◽  
The Other ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Feed Velocity ◽  
Outer Race ◽  
Abrasive Grains ◽  
Other Hand

In order to calculate the grinding force of the basin-like grinding wheel in grinding outer race elliptical grooves, the thesis simplifies the grinding process as follow: the evenly distributed abrasive grains move around grinding wheel axis along an imaginary ellipse at high speed, while the imaginary ellipse moves along the trace deflected from the grinding wheel axis simultaneously. The analysis of grinding force in CVJ outer race elliptical groove grinding with basin-like grinding wheel reveals that, the grinding force will be decreased, if wheel velocity increased and feed velocity decreased. On the other hand, with the decrease of inter-grain spacing, the grinding force of basin-like grinding wheel will be increased, but the grinding force of abrasive grit will be decreased.

Experimental Research on High Speed Grinding of Silicon Nitride Ceramic Spindle

2016 ◽  
Vol 874 ◽  
pp. 253-258
Author(s):  
Ke Zhang ◽  
Jian Sun ◽  
He Wang ◽  
Yu Hou Wu
Keyword(s):  
Silicon Nitride ◽  
High Speed ◽  
Linear Velocity ◽  
Grinding Wheel ◽  
Feed Speed ◽  
Silicon Nitride Ceramic ◽  
Technical Parameters ◽  
Internal Grinding ◽  
Brittle Rupture ◽  
High Speed Grinding

Grinding is a main method of silicon nitride ceramic in finish machining stage. The technical parameters had an important influence on the surface quality of silicon nitride ceramic. The silicon nitride ceramic spindle was ground by the high-speed cylindrical grinder MGKS1432-H. The relations between different speed parameters and surface roughness were researched. The cylindrical and internal high speed grinding experiments of silicon nitride ceramics spindle were carried out. The S-4800 scanning electron microscope was used to explore the roughness change rule of the grinded surface under the condition of only changed grinding wheel’s velocity. In the process of cylindrical and internal grinding on silicon nitride ceramic spindle, the roughness tended to decrease with the linear velocity increasing, and increased with the radial feed speed increasing and decreased with the wheel shaft’s oscillation speed increasing. The result indicated that the linear velocity of grinding wheel influenced the sample’s roughness most. The effect of radial feed speed on the roughness is next only to the effect from linear velocity. The effect of shaft’s oscillation speed on the roughness is the lowest of the three factors. In the process of internal grinding, with the linear velocity increasing, the ceramic material transformed from brittle rupture to plastic deformation and the roughness appeared one peak. These results were very helpful to optimize the grinding parameters and improve grinding efficiency.

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