Li Xiu Zhang

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 on the Factors of Surface Morphologies on Si3N4 Ceramic Internal Grinding

Different grinding parameters of silicon nitride ceramic are researched at the process of internal grinding. The influences on the roughness of surface by the linear speed of grinding wheel (vs), radial feeding speed (f) and axial vibration speed (fa) are studied in the uniformity testing. The experimental equation of silicon nitride ceramic internal grinding is optimized. The machined surface morphologies of the ceramic specimen are measured by roughness instrument of Taylor-Hobson Surtroni-25 and scanning electron microscope of S-4800. The results show that with the increasing of the linear speed of grinding wheel the roughness of surface get reduced, and with the increasing of radial feeding speed the roughness of surface get raised. It is also inversely proportional to the axial vibration speed. The linear speed of grinding wheel has the biggest impact on the roughness of surface of the silicon nitride ceramic internal grinding among the three grinding parameters. With the increasing of linear speed of grinding wheel, the value of roughness of surface declines from 0.4095μm to 0.1726μm. The influences on the roughness of surface of the silicon nitride ceramic internal grinding by different factors are found out in the research, and its removal mechanisms are cleared up under different linear speeds of grinding wheel.

Analysis of Spindle Rotary Precision Based on Two-Point Methods

Two-point method designed of the test system for application, the precision of the motorized spindle rotation was dynamic measurements. The system consists of standard bars, high-precision non-contact eddy current sensor. Analyzed by a mathematical model to establish error separation, measurement of two spindle rotation accuracy. The use of two isolated error method for processing the experimental data obtained spindle rotation accuracy at different speeds. Studies have shown that when the spindle speed of 10,000 rpm rotational error is small and tends to be more stable. Identify the factors that affect the accuracy of spindle rotation and summarized. Spindle rotation accuracy on-line monitoring and speed control provides an important theoretical, experimental basis.

Analysis on the Effects of Cooling Water Velocity on Temperature Rise of Motorized Spindle

In order to obtain the optimal cooling water velocity, the relationship between motor spindle temperature and cooling water velocity was derived by using the heat transfer and fluid mechanics. When the cooling water velocity was relatively small, its change has significantly influence on cooling effect; But when the cooling water velocity was relative large, the difference in cooling effect was inappreciable. Motor spindles water cooling system based on the software of ANSYS CFX was established. The cooling water velocity and temperature distribution in circular channel was analyzed. Motor spindle temperature of theory and simulation was compared under different cooling water velocity; Experiments were conducted according to the results of the simulation, Experimental temperature is consistent with simulation results, which verify the validity of motorized spindle simulation analysis and theoretical derivation. The study in this paper provides a reference for the motorized spindle selecting the rational velocity of cooling water.

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 laboratorys 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.

The Simulation Research of High-Speed Motorized Spindle Vector Control System with a Fuzzy Speed Controller

The quality of high-speed machining workpiece is determined by drive control performance of motorized spindle. Vector control is one of high-speed motorized spindle control method, but the traditional controller is difficult to effectively overcome parameter disturbances caused by parameter variations from internal and external system. So it is necessary to use intelligent control. In this paper, a model of a speed and flux-closed-loop vector control system with an inner torque-closed loop is established, and a fuzzy controller is used to adjust the speed. MATLAB is used for load simulation of high-speed segment of motorized spindle, and then the simulation results show that high-speed motorized spindle can be increased in to the high-speed segment using a short period of time, and it has strong anti-interference ability and excellent performance at the same time in the control system presented in this paper.

Finite Element Analysis about the Influence that High-Speed Motorized Spindle Spindle System Material has on its Temperature Field

The article has analyzed the changes of temperature of different materials of the spindle, and considered 170SD30 Ceramic Motorized Spindle and the same model Metal Motorized Spindle as the research objects, analyzed the inside heat source and heat transfer mechanism of the high-speed motorized spindle; used finite element software to set up the model of the motorized spindle, and did simulation and analysis. Verified by simulation, heat transfer rate of ceramic materials is slower than the metallic materials, in actual operation of the process, due to different materials have different heat transfer rate, so the temperature distribution of the different materials of motorized spindle are different. This conclusion provides the basis to solve motorized spindle temperature field distribution.

Modeling and Simulation Analysis of Motorized Spindle Vector Control

In this paper, a vector control model based on MRAS with speed sensorless is established and observed the influence of parameters on the output waveform of speed and torque by changing the parameters of and in PI regulator of speed calculating module. Experimental results show that the precision of speed recognition is affected by the parameters and . It is verified that the optimal value of and in the model is when is 4400 and is 1.98.

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.

Vibration and Noise Monitoring of Ceramic Motorized Spindles

High speed machining (HSM) technology is used in a broad range of applications to machine ferrous metals and nonmetallic material. The motorized spindle is one of the major elements to keep the machine running at high productivity. In recently years, the requirement of rotational speed and rigidity of motorized spindle is getting higher and higher in order to satisfy the high speed processing. Engineering ceramic is the ideal material for high-speed and high precision electrical spindle due to perfect characteristics of light weight, wear resistance, high temperature, high strength, and so on. So a ceramic motorized spindle is designed for higher speed and rigidity. The shaft and bearing of the motorized spindle are made from ceramic material and other parts are made from metal. Rated power of this electrical spindle is 15Kw; its torque is 14Nm and revolving speed is up to 30,000 rpm as maximum. Motorized spindle is a typical mechatronics product and its dynamic property is very important. The signal of vibration and noise of motorized spindle may display its running status, so the vibration and noise of motorized spindle is an important index in the dynamic performance. This paper monitors the vibration and noise of ceramic motorized spindles using spectral analysis techniques. The effects of rotating speed and lubrication condition on vibration and noise of the ceramic electrical spindle are analyzed. These results are very helpful to the structure optimization and application of the ceramic motorized spindle.