Electrical feed drives for machines tools /
edited by Hans Gross.
- Berlin : Siemens, 1983
- 363 p.
CONTENIDO 1. Feed Drive and Position Control Loop 13 Basics of Control Theory 13 Open and Closed Loop Control 13 Stationary Systems Behavior 14 Characteristic Curves 14 Linearization 15 Normalized Values 16 Referenced Values 18 Dynamic Systems Behavior 18 Differential Equations 18 Transient Response 22 Frequency Response Curve 26 Bode Diagram 29 Linkage of Transfer Elements 32 Frequency Response Curve Symbol for Control Loops 34 Experimental Determination of the Frequency Response Curve 35 Basics of the Position Control Loop 36 Construction and Functioning of the Position Control Loop 36 Localization 38 Measuring Value Detection 38 Measuring Procedures 39 Location of Measurement 39 Characteristic Values and Properties ofPosition Control Loops 40 Dynamic Systems Behavior of Single Control Loop Elements 41 Explanation Terms 44 Behavior Linear Position Control Loops 44 Non-linearities in the Position Control Loop 50 Position Loop Gain 52 Position Control Loop Model 52 Settling Time and Overshoot Width at Positioning 53 Ramp Distance for Thread Cutting 56 Contour Deviations on Corners 61 Contour Deviations on Circles 63 Disturbance Transient Response 66 Reqllirements for the Position Loop Gain 67 Bibliography 69 2. DC Motors for Feed Drives 70 Requirements for the Feed Drive 70 Requirements for Stationary Operation 70 DC Shunt Motor 71 Construction Forms 71 Permanent Magnet-excited DC Servo Motors of the Series 71 Electrically Excited DC Servo Motors of the Series 74 Drive Behavior 76 Differential Equation and Block Diagram 76 Stationary Behavior of the Uncontrolled Drive 80 Dynamic Behavior of the Uncontrolled Drive 82 Dynamic Behavior of the Speed-controlled Drive 84 Calculating the Drive Nominal Angular Frequency 86 External Tnertia Effect 92 Dead Time Effect 94 Selection of DC Servo Motors 96 Methods of Calculation 96 Stationary Load 97 Friction and Losses 98 Machining Force 100 Dynamic Load 102 Heating Behavior 111 Periodic Load Changes 111 Overload Behavior 112 Thermal Time Constants 116 Additional Optimization Criteria 118 Energy Content of Moved Masses 118 Attainable Acceleration 119 Drive Comparisons 121 Calculation Scheme 123 Summary of Calculation Formulas 132 Bibliography 133 3. Current Converters for DC Servo Motors 134 Notions and General Overview 134 Requirements 134 Dead Time 136 Form Factor 137 Efficiency 139 Costs 140 Transistor DC Choppers 141 Applications 141 Principie of Operation 141 Driving, Clockwise, 1. Quadrant 142 Driving, Counterclockwise, ITI. Quadrant 144 Braking, Clockwise, IV. Quadrant 144 Brakillg, Counterc1ockwise, n. Quadrant 145 DC Bus 145 Line Synchrollized Thyristor Controllers 146 Generalities 146 Rectitíer and Inverter Operation 147 Circulating Curent-free Connection 149 Circulating Current-conducting Connection 150 6-Pulse Circulating Current - conducting Cross Connection 151 3-Pulse Circulating Current-conducting Anti-parallel Connection 153 6-Pulse Circulating Current-free Anti-parallel Connection 157 2-Pulse Circulating Current- conducting Anti-parallel Connection 159 Controllers 163 Structure of the Control Loop 163 Overcurrent Limitation 164 Subordinated Current Control 165 Speed Control with Current Limit 166 Status Monitor 168 Adaptive Speed Control Influence 169 Selection Criteria 172 Characteristic Values of Converter Circuits 172 Applications for Con verter Circuits 172 Bibliography 175 4. Design Versions of Mechanical Transmission Elements 177 Generalities 177 Requirements for the Mechanical Transmission System 178 Nominal Angular Frequency 180 Stiffness 184 Damping Gradient 185 Non-linearities 189 Reversing Errors 189 Friction 190 Effects of Rhersing Errors and Frictional Reversing Errors 194 Indirect Position Control Measurement 195 Direct Position Control Measurement 198 Moment of Inertia 202 Cylindrical Bodies 202 Linearly Moved Masses 204 Gear Ratio 205 Calculating the Slide Elements of the Drive 205 Feed Screw Drives 205 Construction and Requirements 205 Feed Screw 208 Stiffness of the Feed Screw 209 Moment of Inertia of the Feed Screw 213 Efficiency 215 Feed Screw Lead 216 Lead Accuracy 216 Critical Speed 217 Buckling Strength 218 Ball Screw Nut 220 Feed Screw Bearings 223 Stiffness and Preload 224 Effect of the Bearing Mounting Elements 226 Friction and Temperature Behavior 227 Rack and Pinion Drives 229 Range of Applications, Influencing Variables 229 Stiffness 230 Torsional Stiffness of Shafts 230 Bending Strength of Shafts 231 Radial Stiffness of Shaft Bearings 231 Bending Strength of the Gear Wheel, Pinion, and Rack Teeth 233 Example 233 Preload at the Pinion 236 Machine Slide and Guides 238 Machine Slide 238 Table Guides 239 Requirements 239 Friction Guides 210 Roller Guides 241 Hydrostatic Guides 243 Aerostatic Guides 244 Damping 245 Gears 247 Overview of Applications 247 Requirements 251 Moment of Inertia 251 Torsion and Bending 253 Reversing Errors 254 Toothed Belt Gear 255 Advantage Limits of a Gear Ratio 259 Motors of Equal Frame Size 259 Motors of Different Frame Size 261 Disturbance Transient Response 264 Comparison of two Motors 264 Couplings 266 Bibliography 268 5. Command Value Modification 271 Purpose of the Command Value Modification 271 Smoothing the Command Values 271 Effects ofCommand Vallle Smoothing 275 Stress and Contour Deviation Characteristics 275 Contour Movements 276 Diagrams for Contour Deviation and Stress Characteristics 279 Determining the Command Value for Acceleration 284 Conclusions 287 Bibliography 287 6. Measurements on Feed Drives 288 Substantiation, Aim 288 Measuring Procedures 289 Measurements on the Mechanical Transmission Elements 289 Reversing Error (Back Lash) 290 Total Stiffness, Nominal Angular Frequency 295 Friction Characteristics 296 Measurements on the Speed Control Loop 298 Step Response, Transient Response 299 Current Limit 301 Motor Heat 301 Nominal Angular Frequency of the Feed Drive 302 Measurements on the Position Control Loop 304 Contour Deviations 304 Measuring the Position Loop Gain 306 Measurements for the Smallest Position Increments 308 Positioning Response 309 Measuring Values of Machines in Use 310 Evaluation of Measured Frequency Response Curves 310 Measurements on a Timing Belt Gear 311 Effect of the Moment of Inertia 314 Motors in Short Version 314 Effects of Optimization of the Speed Control 316 Frequency Response Curve of a Shell Magnet Motor 316 Influence of the Con verter Circuit 318 Frequcncy Rcsponse Curve of an Electrically Excited DC Servo Motor 320 Conclusions 321 7. Technical Data 322 DC Servo Motors 322 General Data 322 Design Series 1 HU 325 Design Series 1 GS 3 331 Current Converter Units 334 Transistor DC Choppers 334 Line-synchronized Thyristor Controllers 336 8. Technical Appendix 339 Symbols and Units Used 339 SI Units 350 Conversion Tables 353 Equations 356 Index 358
0471262730
TECNOLOGIA DEL CONTROL EQUIPO DE CONTROL ELECTRICO FEED DRIVE CONTROL LOOP SERVO MOTORS MECHANICAL TRANSMISSION MACHINE TOOLS