Avoidance of Cutter Retracting Interference in Noncircular Gear Shaping Through 4-Linkage Model

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Fangyan Zheng ◽  
Hua Lin ◽  
Xinghui Han ◽  
Mingde Zhang ◽  
Weiqing Zhang ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Machine Tool ◽  
Cutting Process ◽  
Cutting Experiment ◽  
Noncircular Gears ◽  
Pitch Curve ◽  
Gear Shaping ◽  
Linkage Model

Gear shaping, a widely used machining method for circular gears, was generalized to noncircular gears in recent works using a 3-linkage machine tool. As the pitch curve normals of noncircular gears change constantly in processing, angles may exist between the pitch curve normals and the cutter relieving direction, bringing in turn cutter retracting interference. Regarding this, the paper proposes a 4-linkage shaping method. Through linkage motion of 4 machine tool axes, noncircular gear pitch normals are along the cutter relieving direction, avoiding completely cutter retracting interference. On such basis, a mathematical model is first established, the cutting process is then discussed and a cutting experiment is finally carried out, proving the validity of the proposed method.

Study on the pitch curve with minimal rotary inertia for the noncircular gears

2017 ◽  
Vol 232 (15) ◽  
pp. 2666-2673
Author(s):  
Xin Zhang ◽  
Shouwen Fan
Keyword(s):  
Mathematical Model ◽  
Calculus Of Variations ◽  
Design Method ◽  
High Load ◽  
Rotary Inertia ◽  
Slow Response ◽  
Numerical Examples ◽  
General Mathematical Model ◽  
Noncircular Gears ◽  
Pitch Curve

Aimed at the high load and slow response of the noncircular gears design, a general mathematical model for designing the pitch curve with minimal rotary inertia of the noncircular gear is proposed by resorting to kinematics principle and calculus of variations. To achieve the closure design, the constraint conditions and smoothness characteristics of N-lobed noncircular gear pitch curve with minimal rotary inertia are established and calculated analytically. In addition, the unified design method of the conjugate pitch curves with minimal rotary inertia for the noncircular gears is given in this paper. Unclosed and closed N-lobed conjugate pitch curves that satisfy the desired transmission requirements can be easily solved by using the proposed method, and each lobe has identical profile to ensure the periodical motion of the pitch curves. Numerical examples are implemented in computer and demonstrate the feasibility of the above method.

Mathematical Model for the Influence of Machine Tool Parts Deformation on Machining Accuracy

2014 ◽  
Vol 556-562 ◽  
pp. 1354-1357
Author(s):  
Li Gong Cui ◽  
Gui Qiang Liang ◽  
Fang Shao
Keyword(s):  
Mathematical Model ◽  
Mathematical Method ◽  
Machine Tool ◽  
Cutting Tool ◽  
Lower Surface ◽  
Design Stage ◽  
Machining Accuracy ◽  
Cutting Point ◽  
The Mathematical Model

This paper presents a mathematical method to analyze the influence of each machine tool part deformation on the machining accuracy. Taking a 3-axis machine tool as an example, this paper divides the machine tool into the cutting tool sub-system and workpiece sub-system. Taking the deformation of lower surface of the machine bed as the research target, the mathematical model of the deformation on the displacement of the cutting point was established. In order to distribute the stiffness of each part, the contribution degree of each part on the machining accuracy was analyzed. Using this mathematical model, the stiffness of each part can be distributed at the design stage of the machine tool, and the machining accuracy of the machine tool can be improved economically.

scholarly journals Development of turning process digital twin based on machine learning

2021 ◽  
pp. 32-41
Author(s):  
D. A. Rastorguev ◽  
◽  
A. A. Sevastyanov ◽  
Keyword(s):  
Neural Networks ◽  
Mathematical Model ◽  
Artificial Neural Networks ◽  
Information Technologies ◽  
Cutting Process ◽  
Turning Process ◽  
Force Load ◽  
Cnc Machine ◽  
Digital Twin ◽  
Artificial Neural

Today, manufacturing technologies are developing within the Industry 4.0 concept, which is the information technologies introduction in manufacturing. One of the most promising digital technologies finding more and more application in manufacturing is a digital twin. A digital twin is an ensemble of mathematical models of technological process, which exchanges information with its physical prototype in real-time. The paper considers an example of the formation of several interconnected predictive modules, which are a part of the structure of the turning process digital twin and designed to predict the quality of processing, the chip formation nature, and the cutting force. The authors carried out a three-factor experiment on the hard turning of 105WCr6 steel hardened to 55 HRC. Used an example of the conducted experiment, the authors described the process of development of the digital twin diagnostic module based on artificial neural networks. When developing a mathematical model for predicting and diagnosing the cutting process, the authors revealed higher accuracy, adaptability, and versatility of artificial neural networks. The developed mathematical model of online diagnostics of the cutting process for determining the surface quality and chip type during processing uses the actual value of the cutting depth determined indirectly by the force load on the drive. In this case, the model uses only the signals of the sensors included in the diagnostic subsystem on the CNC machine. As an informative feature reflecting the force load on the machine’s main motion drive, the authors selected the value of the energy of the current signal of the spindle drive motor. The study identified that the development of a digital twin is possible due to the development of additional modules predicting the accuracy of dimensions, geometric profile, tool wear.

scholarly journals Design of Vegetable Pot Seedling Pick-up Mechanism with Planetary Gear Train

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Zhipeng Tong ◽  
Gaohong Yu ◽  
Xiong Zhao ◽  
Pengfei Liu ◽  
Bingliang Ye
Keyword(s):  
Design Method ◽  
Planetary Gear ◽  
Gear Train ◽  
Dimensional Synthesis ◽  
Planetary Gear Train ◽  
Key Points ◽  
Physical Prototype ◽  
Noncircular Gears ◽  
Pitch Curve ◽  
Parameter Values

Abstract It has been challenging to design seedling pick-up mechanism based on given key points and trajectories, because it involves dimensional synthesis and rod length optimization. In this paper, the dimensional synthesis of seedling pick-up mechanism with planetary gear train was studied based on the data of given key points and the trajectory of the endpoint of seedling pick-up mechanism. Given the positions and orientations requirements of the five key points, the study first conducted a dimensional synthesis of the linkage size and center of rotation. The next steps were to select a reasonable solution and optimize the data values based on the ideal seedling trajectory. The link motion was driven by the planetary gear train of the two-stage gear. Four pitch curves of noncircular gears were obtained by calculating and distributing the transmission ratio according to the data. For the pitch curve with two convex points, the tooth profile design method of incomplete noncircular gear was applied. The seedling pick-up mechanism was tested by a virtual prototype and a physical prototype designed with the obtained parameter values. The results were consistent with the theoretical design requirements, confirming that the mechanism meets the expected requirements for picking seedlings up. This paper presents a new design method of vegetable pot seedling pick-up mechanism for an automatic vegetable transplanter.

Analysis on Effect of Cooling Oil Temperature on Cutting Stability of Gear Shaping Machine

2014 ◽  
Vol 651-653 ◽  
pp. 647-650
Author(s):  
Hai Tao Yu ◽  
Lie Chen ◽  
Chang Bing Zhou ◽  
Rui Wen Guo
Keyword(s):  
Machine Tool ◽  
Processing System ◽  
Cutting Stability ◽  
Capability Index ◽  
Cutting Test ◽  
Machine Tool Accuracy ◽  
The Stability ◽  
Gear Shaping ◽  
Accuracy And Stability

With the demands of machine tool accuracy and stability for manufacturing are getting higher and higher, the effect of cooling oil is increasingly evident. And it is proved that cooling oil temperature is an important factor for machine cutting precision and stability. Continuous cutting test was carried on and values of over pin dial (M) were measured. The results show that it has large effect of cooling oil temperature on the stability of M-value. Subsequently, test of machine capability index (CMK) was carried on. And it was verified that the CMK of gear shaping machine is larger than 1.67. And the results show that the fluctuation of M values is the smallest when cooling oil temperature is 33°C. Lowest time costing for adjusting the processing system, highest cutting accuracy, and smallest value of stable amplitude for Gear Shaping Machine could be obtained at this condition.

Study on Meshing Characteristic and CAM Technology of Eccentric Involute Gears

2012 ◽  
Vol 479-481 ◽  
pp. 917-920
Author(s):  
Yong Ping Liu ◽  
Peng Fei Meng ◽  
Chi Bing Hu
Keyword(s):  
Design Method ◽  
Shape Design ◽  
Digital Manufacturing ◽  
Transmission Characteristics ◽  
Systemic Theory ◽  
Theoretical Design ◽  
Parameterized Modeling ◽  
Involute Gears ◽  
Noncircular Gears ◽  
Pitch Curve

According to the meshing principle of noncircular gears, the meshing characteristic and digital manufacturing technology of eccentric involute gears is studied. Based on analyzing the parameterized modeling of pitch curve, transmission characteristics and convex-concave property on eccentric involute gears, the transmission feasibility of this type gear is proved. Through tooth shape design, CAM calculation and processing simulation, the validity and manufacturability of theoretical design method on this type gear is proved. The research results can provide more systemic theory basis for the design, manufacture, measure and application of eccentric involute gears.

Sensorless Simultaneous Rotary-Translational Axis Motion Error Measurement and Trace Based on Virtual Bar

2010 ◽  
Author(s):  
Yuqing Zhou ◽  
Xuesong Mei ◽  
Gedong Jiang ◽  
Nuogang Sun ◽  
Bai Shao
Keyword(s):  
Mathematical Model ◽  
Feature Extraction ◽  
Wavelet Transform ◽  
Machine Tool ◽  
Error Measurement ◽  
Error Source ◽  
Spatial Error ◽  
Motion Error ◽  
Circular Test ◽  
The Mathematical Model

Simultaneous rotary-translational (R-T) axis motion error has significant influence on multi-axis machine tool precision. To improve multi-axis machine tool precision, axis motion error measurement and trace method are investigated in this study. A sensorless R-T axis motion error measurement and trace technology based on virtual bar is proposed. Firstly, the fundamental sensorless test principle is discussed. Then, the virtual-bar-based test path of a circular test though a rotary axis and two translational axes motion is scheduled. The mathematical model of motion error is established. Furthermore, to identify the error source, spatial error charts and some advanced signal processing and feature extraction technologies, such as wavelet transform and frequency analysis, are used. The analysis of experimental results shows that it is practical and efficient to use the virtual bar and the sensorless information to estimate motion error.

Cutting Dynamics in Machine Tool Chatter: Contribution to Machine-Tool Chatter Research—3

1965 ◽  
Vol 87 (4) ◽  
pp. 464-470 ◽  
Author(s):  
R. L. Kegg
Keyword(s):  
Machine Tool ◽  
Metal Cutting ◽  
Chip Thickness ◽  
Cutting Process ◽  
Dynamic Force ◽  
General Technique ◽  
Cross Sensitivity ◽  
Machine Tool Chatter ◽  
Measuring Techniques ◽  
Tool Chatter

This is one of four papers presented simultaneously on the general subject of chatter. This work is concerned with finding a representation of the dynamic metal-cutting process which is suitable for use in a linear closed-loop theory of stability of the system composed of the machine tool structure, the cutting process, and their means of combining. Measuring techniques for experimentally determining this behavior are discussed and some problems in the dynamic measurement of forces are explored. It is found that it is not at all sufficient to simply build a dynamometer whose lowest natural frequency is well beyond the range of interest. It is also shown that dynamic cross sensitivity can far exceed static cross sensitivity so that a more general technique for data correction developed in the present work must be used to calibrate dynamic force data. Results obtained to date with an oscillating tool and a flat uncut surface show that some phase, increasing with frequency, is always present between the dynamic cutting forces and the oscillatory uncut chip thickness. This phase is different for the two components of the resultant cutting force. It is felt that two mechanisms, both associated with the tool clearance flank, can explain most of the dynamic cutting effects found in testing.

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