Electric Spindle Research Articles

The Accuracy of the Plastic Parts Milling Process Executed by a Six Axes Robot

The objective of this paper is to analyze the precision of plastic parts made by using robot milling. Currently, the robots have good precision, rigidity, flexibility and they are able to machine parts. By using a six axis Kuka robot and an electric spindle, a plastic part was milled. The paper presents the advantages and disadvantages of this new technology, analyzing the dimensional accuracy, surface quality and costs.

An Energy Analysis of Electric and Pneumatic Ultra-high Speed Machine Tool Spindles

There is a growing demand for ultra-high speed precision machine tool spindles to create complex miniature devices and features, in consumer markets such as medical devices, electronics and communications. The key enabling drive technologies for spindle rotational speeds in the 100,000rpm range includes electric motors, both AC and DC powered, and air turbines. In particular for high speed micromachining, turbine spindles have advantages in terms of precision and cost. A widely considered drawback of pneumatic technology though is low energy efficiency, but to date there has been little in depth analysis of commercial/state-of-art turbo-spindle energy performance. This paper provides a holistic comparative analysis of electric motor and turbine powered spindle electrical power requirements, by including the power demand of supporting systems and infrastructure. The analysis indicates that at present the energy usage associated with turbine spindles is significantly higher than electric spindles. However, a number of technically feasible energy efficiency measures are identified for turbine spindles, which would make their energy performance comparable with electro-spindles. The analysis and results will contribute towards an overall life cycle assessment of high speed turbo-spindle technology, and provide impetus to further explore energy optimization approaches and methods.

Two-Dimensional Magnetotelluric Forward Research for the Vertical Anisotropy

When we study and process magnetotelluric data, the earth's interior structure is usually equated with isotropic medium in the existing approaches. When the underground structure is complex, there is serious resistivity anisotropy in macroscopic view, and then the traditional processing and interpretation methods often produce wrong results. For that we must establish the study method based on the anisotropy in order to explain the measured data exactly. In this paper, by considering the change of resistivity in three electrical spindle directions, we deduce two-dimensional magnetotelluric variational equation for vertical anisotropy. The study region is divided into many rectangular units, and it is dealt with linear interpolation in each of them. By comparing with former achievements including the results of the isotropic and anisotropic models, it demonstrates the validity of the program. The pseudosection map of vertical anisotropic body shows that we can’t ignore the anisotropy effect and provides a solid foundation for the further inversion study.

Thermal Structure Coupling Analysis of Lathe Built-In Electric Spindle under Intermittent Load

Built-in electric spindle has been the core component of machine tool, whose temperature problem is serious. Internal heat source are greatly influenced by load. Based on which has the function of automatic clipping chuck inversion type vertical lathe built-in electric spindle prototype as the research object, using the theory of thermal stress and finite element, established the intermittent load cases hot - structure coupling numerical analysis model of the electric spindle. After overall analyzing electric spindle within the transient temperature field under the action of the intermittent load, the winding temperature changing with time curve is given. On that basis, electric spindle thermal deformation has been carried on the analysis and calculation, gets the shaft extension end axial thermal deformation, provides theoretical basis for the thermal error compensation.

Assessment of wood particleboards milling by means of energy consumption tests

In this paper, an experimental procedure is proposed, in order to evaluate the machinability of different particleboards. A dedicated test stand has been built to measure the power consumption during the process for different typologies of particleboards. This methodology could constitute a quick particleboard grading system, in order to maximise the feeding rate during the working process, and, at the same time, minimise the tool wear and the loads on the shaft of the electrical spindle, with a considerable improvement in the overall production costs.

The NC Grinding Machine Rebuilding for TG30 NC Lathe

Based on the characters of NC lathe and NC grinding machine, the NC grinding machine rebuilding for TG30 NC lathe is studied in this paper. According to the geometric parameters of grinding, choose appropriate TG30 NC lathe, keep the driving system of spindle and the feeding function of two axle linkage of NC lathe, increase the high speed rotating grinding head electric spindle, to realize the one-time processing of inner hole and groove fillet R grinding.

Based on ANSYS Workbench High Speed Electricity Spindle Dynamics Characteristic Analysis

This paper describes the inherent characteristics, dynamic response and dynamic stability dynamics of vibration capability that impacts of high-speed electric spindle. Taking the high-speed, high-power electric spindle milling center on as the object of the research, modal analyzing of electric spindle with the finite element software ANSYS Workbench, researching the spindle modes, natural frequencies and critical speed of electric spindle, to get each frequency and vibration type, pointed the affection of what spindle away from the anti-vibration frequency requirements, well before bearing stiffness and damping of the vibration to the spindle system. It provides the necessary basis for further dynamic analysis by modal analysis.

The Electric Spindle Built-in Motor Thermal Equilibrium Active Temperature Control Model

Based on the structure characteristics of electric spindle built-in motor and numerical heat transfer theory,electric spindle built-in motor physical heat conduction model was given and a mathematical temperature control model for the electric spindle built-in motor was established. According to the mathematical temperature control model, controllable factors for the heat balance was determined. By electric spindle own screw channels, using this mathematical temperature control model to adjust the flow speed and fluid medium temperature, the built-in motor quickly reached heat balance and maintained temperature field stability in the electric spindle start-stop and using process. Then the theoretical calculations and simulation on the electric spindle built-in motor was conducted.This model is designed to enhance high-speed precision spindle machining accuracy and the use of performance.Nomenclature:

Experimental Modality Analysis of Ceramic Motorized Spindle

The unit of Electric spindle is decided processing speed and precision of the machine key functional components, it determines the development direction of machine tool industry. Use high-performance structure ceramic as electric spindle of spindle, bearing main of rotating parts material, mainly use ceramic material density is small, hardness higher good characteristics, improve the inherent frequency and life axis. Based on the modal analysis theory, the use of the laboratory's hammer excitation 170SD30 models of the ceramic motorized spindle by experimental modal analysis got its first three order inherent frequency and critical speed. Results show that all the ceramic motorized spindle rated frequency far below its first order natural frequency, rated speed far below its first order critical speed, it can effectively avoid resonance region that ensure the process accuracy.

Comprehensive Test of Electric Spindle Based on Thermal Stress

This document explains the details of electric spindle thermal characteristics experiments. The temperature distribution, shaft deformation and the stress of temperature sensitive points are tested. Thermal characteristics are gathered about the different cooling strategies and different spindle speeds in the experiments results analysis. Choosing reasonable cooling strategy can use to design spindle cooling system. Thermal stress test can obtain accurate data at temperature sensitive points. The stress analysis can be used to reflect spindle deformation.

Dynamic Analysis of Electric Spindle Based on ANSYS

Building a finite model of the electric spindle by ANSYS. Using Lanczos to extract first 4 natural frequencies and vibration models of the spindle, and using Harmonic response analytic methods to obtain dynamic response in different excitation of electric spindle .The results show that the static stiffness of electric spindle can meet the requirements, because the highest work speed of Spindle is far away from the critical rotational speed, it can avoid the resonance phenomenon effectively. It lays the foundation of Optimization design and Remanufacturing of the spindle.

Analysis about the Influence of Load on Loss of the Ceramic Spindle

The increase of loss causes the temperature rise in motor, reducing the using life of spindle, which can seriously affect the performance of motor. Thus, accurate calculating of loss is meaningful to optimal design of electric spindle. In this paper, the losses both with load and without load were analyzed by time-step finite element method. As the result of simulation analysis, the spindle losses with load are higher than those without load. Comparison analysis indicates that losses are various with different load. And the load impacts on core loss mostly in ceramic spindle. In addition, in asynchronous ceramic spindle with 4N•m rated load, the core loss, solid loss and stranded loss are least when the load change from 1.8 N•m to 3.8N•m. Accordingly, the best operation condition under the influence of load in electric spindle is gained.

Analysis of Influence to Electric Spindle Losses Caused by Carrier Ratio in Frequency Converter

Aiming at analyzing the influence to ceramic electric spindle and metal electric spindle caused by carrier ratio in frequency converter, in this paper, the time-step finite element model was built based on SPWM method. The changing law of the loss in different carrier ratios were gained by simulation. The result shows that the greatest impact by carrier ratio is solid loss, the least is core loss. The ceramic electric spindle is less impact by carrier ratio than metal electric spindle. Additionally, the corresponding carrier ratio with minimum loss in both ceramic electric spindle and metal electric spindle were found.

Structure Design and Analysis of a High-Speed Camshaft Grinding Carriage

In this paper, the overall structure of a high-speed camshaft grinding carriage and the key components such as electric spindle system and feed system are presented. The model analysis of the electric spindle and grinding carriage box is established to verify the feasibility of the design.

The active vibration attenuation of a built-in motorized milling spindle

An active vibration control scheme is proposed for suppressing the vibration of the high-speed induction electric spindle with a built-in force actuator to improve the performance of high-speed milling system. The built-in force actuator is a set of windings, which are added to the stator of electric spindle motor. An improved fast block least mean square (FBLMS) adaptive filter is adopted to produce the reference control force, which is used to obtain the control current of force actuator, and then a controlled, non-contact electromagnetic control force on the electric spindle is produced by the force actuator to control actively chatter, unbalanced vibration and disturbance signals of milling system. The built-in motorized spindles dynamic is modeled by means of the finite element method, the dynamic milling, the air gap excitation current of torque and radial electromagnetic control force are modeled, the control force coefficient and the unbalanced magnetic pull force coefficient are identified by finite element analysis, and then the active vibration control scheme for the flexible induction electric spindle is designed. The vibration, with a different frequency component, is investigated. The results show that the improved FBLMS adaptive filter and the proposed active control scheme have an obvious effect on suppressing the spindle chatter, unbalanced vibration and other frequency vibration components in the built-in motorized milling spindle.

Analysis of Z-axis rigid of PCB CNC drilling machines

This article for the printed circuit board (PCB) CNC drilling machine dynamic character and rigidity analysis of Z-axis, With ADAMS motion simulation of the Z-axis program, come to the bit offset of the rig during the drilling process in the X-axis and Y-axis direction, and then use the quadratic elements of the completed prototype data test, the measured data and simulation data compare validation to identify the impact of the motion parameters of accuracy of ultra-high-speed electric spindle drilling. Using ANSYS on the overall structure (in particular, the structure of Z-axis) to optimize the structure analysis, the optimal structural parameters. This article both specific theoretical analysis, but also the experimental verification, through theoretical analysis and experimental validation of the Z-axis structure play an important role to improve the ultra-high-speed electric spindle dynamic accuracy and rigidity in the drilling process. DOI: http://dx.doi.org/10.11591/telkomnika.v10i6.1421 Full Text: PDF

Fault Detection of a High-Speed Electric Spindle

The high-speed electric spindle is the key part of the machining center which performing high speed precision machining. In order to ensure the electric spindle running under the smooth and steady state, it is necessary to prevent and discover the abnormities during the running process of the electric spindle by the experimental test and analysis. In this paper, the vibration order analysis method combined with the experimental modal test is utilized to measure and diagnose the abnormities of a high speed electric spindle.

The Structure Design and Dynamic Characteristic Simulation Analysis of Electric Spindle Using the PC Grinder of Ceramic Ferrule

The PC grinder of ceramic ferrule is the core part of the processing of Optical—fiber Connector. Through the processing equipment, in order to ensuring the product spherical curvature radius is SR14-18mm, eccentric ≤30 µm, surface roughness of less than 0.01 µm. In grinding process for high rotating speed and high precision machining, here used a motorized spindle technology. High speed spindle is widely applied in high speed grinder whit its advantages of light weight, high speed, compact structure, small inertia, good dynamic characteristics and so on.

Design and Analysis of a Grinding Machine for Back Gouging of Outer Circumferential Weld

In order to improve the efficiency of back gouging of large thick wall vessels and the work condition, and to reduce labor intensity, this paper presents a large-power, compact-structure and easy-and-simple-handled grinding machine for back gouging of outer circumferential weld. This grinding machine consists of grinding head, manipulator and guide rail. Since a grinding electric spindle, in which a grinding spindle is directly connected to a motor, is used in grinding head, the structure of the drive system is greatly simplified. Firstly the grinding head can be controlled closer to weld for back gouging in a certain pose by the arm back, up down traverse of the arm, longitudinal and lateral movement of the manipulator. Secondly, radial force can be produced between grinding head and weld line by the arm telescopic and radial force can be kept constant by a flexible device. The manipulator is set up on the guide rail, so it can control the grinding head to accomplish back gouging of multiple welds. When the grinding head is set up on the different functional manipulator, it can accomplish back gouging of internal or outer circumferential-weld and straight-weld. As the power of grinding machine is large and the process of back gouging is high automation, the time of back gouging can be reduced by one fifth to one third and the efficiency of back gouging is significantly improved, and security and comfort of back gouging of weld can be increased as well.

Spindle speed variation in turning: technological effectiveness and applicability to real industrial cases

Spindle speed variation is a well-known technique to suppress regenerative machine tool vibrations especially for low spindle speeds. Although a lot of research effort was made over the years the technique is not widespread in real turning applications. In this paper, the reasons that can limit the diffusion of the spindle speed variation were investigated. Therefore, the analysis of spindle speed variation strategy was not only focused on its chatter suppression properties but also on some more general technological aspects: the surface quality of the machined components, the cutting edge-spindle bearings load and the thermal overload the electrical spindle motor is subjected to when the speed modulation is used. A time-domain numerical model of the turning process was developed and exploited to support the analysis. A lot of cutting tests were also performed both to validate the numerical model and to evaluate the effect of variable spindle speed on surface quality. Finally, some real industrial applications were analyzed focusing on thermal overload issue of the spindle motor.