Andrea Vacca - Hydraulic Fluid Power

26 Chapter 26Figure 26.1 Open circuit hydrostatic actuator using counterbalance valves.Figure 26.2 HA circuit with single acting cylinder.Figure 26.3 Primary control of a differential cylinder in closed circuit.Figure 26.4 System behavior for the case of cylinder extension with resistiv...Figure 26.5 System behavior for the case of cylinder extension with low resi...Figure 26.6 System pressures for the case of cylinder extension.Figure 26.7 System behavior for the case of cylinder retraction with assisti...Figure 26.8 System behavior for the case of cylinder retraction with resisti...Figure 26.9 System pressures for the case of cylinder retraction.Figure 26.10 Summary of the operating conditions for the hydrostatic actuato...Figure 26.11 Closed circuit HA with accumulator and charge circuit sequence ...

27 Chapter 27Figure 27.1 Variables involved in the control of a hydraulic motor through s...Figure 27.2 Basic implementation of the secondary control principle inclusiv...Figure 27.3 One of the first concepts for controlling the displacement of a ...Figure 27.4 Regulation of the velocity of the secondary unit for the system ...Figure 27.5 Secondary control circuit with tachometric pump and additional f...Figure 27.6 Secondary control unit with full electronic feedback of speed, d...Figure 27.7 Secondary control circuit with multiple actuators.

28 1Figure A.1 A crane is a typical example of application where the combination...Figure A.2 Comparison of available torque (continuous line) and power (dotte...Figure A.3 Torque and power curves for a diesel engine. The chart shows how ...Figure A.4 Interaction between diesel engine and hydraulic pump.Figure A.5 Examples of machines powered by a diesel engine with different op...Figure A.6 Example of brake‐specific fuel consumption map for 150 kW to 700 ...Figure A.7 Operating principle and simplified implementation of a DC brushed...Figure A.8 Classification of DC brush motors based on type of excitation.Figure A.9 Torque vs. speed curves for different types of DC brushed motors....Figure A.10 DC power unit and equivalent schematic. A thermal switch (not re...Figure A.11 Performance curves of a DC power unit using a PM motor for diffe...Figure A.12 Example of duty cycle ratings for a DC power unit.Figure A.13 Two simple methods for controlling the speed of DC motors. The v...Figure A.14 The principle of operation of AC motors can be represented as a ...Figure A.15 Induction motor implementation with a single‐phase current.Figure A.16 Three‐phase and two‐pole induction motor: the rotating magnetic ...Figure A.17 Typical characteristic of an AC asynchronous induction motor.Figure A.18 Characteristic of an AC induction motor with variable frequency ...Figure A.19 Hydraulic power unit with induction motor and variable displacem...Figure A.20 Principle of operation of a synchronous motor with three pole pa...Figure A.21 Typical torque and power characteristics of a synchronous motor....Figure A.22 Torque limitation using two fixed displacement pumps.Figure A.23 Operating areas of a power limited supply using two fixed displa...Figure A.24 Common method for limiting the torque for an axial piston pump....Figure A.25 Detailed operation of the power limiting device.Figure A.26 Pressure–flow characteristic of a variable displacement pump wit...Figure A.27 Power limiting control integrated with load sensing and max pres...Figure A.28 Torque limiting control based on a cam‐adjusted relief valve.Figure A.29 Operating area for a cam‐operated torque limiting control.

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2 Table of Contents

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