Thermal-mechanical coupling calculation method for deformation error of motorized spindle of machine tool

Author(s):  
Yangfan Li ◽  
Yingjie Zhang ◽  
Yanqing Zhao ◽  
Xiaojun Shi
2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Dazhong Wang ◽  
Yan Lu ◽  
Tongchao Zhang ◽  
Keyong Wang ◽  
Akira Rinoshika

Dynamic characteristic of ball screw feed system in a milling machine is studied numerically in this work. In order to avoid the difficulty in determining the stiffness of rolling joints theoretically, a dynamic modeling method for analyzing the feed system is discussed, and a stiffness calculation method of the rolling joints is proposed based on the Hertz contact theory. Taking a 3-axis computer numerical control (CNC) milling machine set ermined as a research object, the stiffness of its fixed joint between the column and the body together with the stiffness parameters of the rolling joints is evaluated according to the Takashi Yoshimura method. Then, a finite element (FE) model is established for the machine tool. The correctness of the FE model and the stiffness calculation method of the rolling joints are validated by theoretical and experimental modal analysis results of the machine tool’s workbench. Under the two modeling methods of joints incorporating the stiffness parameters and rigid connection, a theoretical modal analysis is conducted for the CNC milling machine. The natural frequencies and modal shapes reveal that the joints’ dynamic characteristic has an important influence on the dynamic performance of a whole machine tool, especially for the case with natural frequency and higher modes.


Author(s):  
Wu-Sung Yao

This paper presents a system modeling technique for a high-speed gantry-type machine tool driven by linear motors. One feed axis of the investigated machine tool is driven by the joint thrust from two parallel linear motors. These two parallel motors are coupled mechanically to form the Y-axis while another standalone motor fixed to a support forms the X-axis. The components in the X-axis, which is treated as the mechanical coupling, are carried by the slides of the Y-axis motors. This configuration is applied to improve the dynamic stiffness of the system and operation speed/acceleration. However, the precise synchronous control of the two parallel and coupled motors would be the major challenge. To overcome this challenge, a multivariable system identification method is developed in this paper. This method is used to construct an accurate system mathematical model for the target coupled system. A synchronous control scheme is then applied to the model obtained using the proposed technique. The performance of the system is experimentally verified with a high-speed S-curve motion profile. The results substantiate the constructed system model and demonstrate the effectiveness of the control scheme.


2011 ◽  
Vol 179-180 ◽  
pp. 960-966
Author(s):  
Hu Ran Liu

In order to improve productivity and product quality and reduce cost, over the past many years, producers made great efforts to find the new method of chamfering. One of the methods is the chamfer milling cutter, on the milling machine tool. This method is suited for medium and small batch production. The tool life is long, the machining quality is stable. In this thesis, the principle of meshing between gear and the rake is applied. The chamfer miller design principle and calculation method is put forward.


2011 ◽  
Vol 52-54 ◽  
pp. 1206-1211 ◽  
Author(s):  
Huai Xing Wen ◽  
Mei Yan Wang

The thermal characteristics of the motorized spindle determines maching qualities and cutting capabilities, and is one of the important factors influencing the precision of the high speed NC machine tool. To improve the performance of the high speed machine tool, it is important to study the thermal characteristics of the motorized spindle. It had been studied in two ways: one is finite element analysis by Ansys software, in which the finite element analysis model was built. According to the actual working condition, the heat source and the heat transfer coefficient of every part are calculated. On this basis, the temperature field and temperature rises were gotten in Ansys software. The other way is temperature rises experiment on the motorized spindle test platform. The result was shown in the form of curve. These two ways shown the same result: the highest temperature rise appears in the area of electromotor, then followed by the rolling bearing .The result provides the necessary theory basis for optimizing the structure of the motorized spindle and establishes a basis for the research and application about the high speed spindle.


2011 ◽  
Vol 87 ◽  
pp. 59-62
Author(s):  
Peng Zheng ◽  
Xin Bao ◽  
Fang Cui

The thermal deformation error that is the biggest error of effecting the machining precision of Direct-drive A/C Bi-rotary Milling Head was narrated in brief. Based on the introduce of the study status on the thermal error compensation techniques of CNC Machine tool, the momentum of thermal deformation of Bi-rotary Milling Head was analyzed. According to the Trigonometric Relations in A/C axis rotation angle of Bi-rotary Milling Head and the momentum of thermal deformation in Bi-rotary Milling Head and -axis respectively, a thermal error compensation model was established to make the Machine tool to compensate for thermal errors in -axis.


2010 ◽  
Vol 455 ◽  
pp. 33-36 ◽  
Author(s):  
C.Q. Li ◽  
Xiao Dong Zhang ◽  
Q. Zhang ◽  
H. Li

To solve the problems that the thermal deformation of the High-Grade CNC machine tool has much effect on accuracy and quality of the produces, the structure characteristics of the high speed motorized spindle is firstly introduced in this paper. Then one type of motorized spindle and supporting structure are selected, and the thermal boundary parameters are calculated. Much more the static and transient temperature field are simulated by using FEA software ANSYS in one working condition. At last, the main measures to improve the uneven temperature field and the plans to reduce the thermal deformation are put forward, which are provided some technical bases for the equipment to achieve the high-speed and high-precision machining.


2005 ◽  
Vol 71 (704) ◽  
pp. 1392-1399 ◽  
Author(s):  
Hirohisa NARITA ◽  
Hiroshi KAWAMURA ◽  
Takashi NORIHISA ◽  
Lian-yi CHEN ◽  
Hideo FUJIMOTO ◽  
...  

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