液压与气压传动（英汉双语）第2版教学课件作者陈淑梅第7章chapter_7课件.pptVIP

Chapter 7 Basic Hydraulic Circuits 7.1 Pressure Control Circuits 7.2 Speed Control Circuits 7.3 Directional Control Circuits 7.4 Multi-actuator Control Circuits 7.1 Pressure Control Circuits 7.1.1 Pressure regulated circuits 7.1.2 Pressure-venting circuits 7.1.3 Pressure-reducing circuits 7.1.4 Pressure-increasing circuits 7.1.5 Pressure counterbalance circuits 7.1.6 Pressure-holding circuits 7.1.1 Pressure regulated circuits 2. Multistage pressure regulated circuits 7.1.2 Pressure-venting circuits 1. Pressure-venting by the neutral of a directional valve 2. Pressure-venting by pilot -operated relief valve 7.1.3 Pressure-reducing circuits 7.1.4 Pressure-increasing circuits 2. A pressure-increasing circuit by a tandem circuit 7.1.5 Pressure counterbalance circuits 2. Counter control-balance circuits done by a hydraulic control-operated check valve 7.1.6 Pressure-holding circuits 2. A pressure-holding circuits by the accumulator 7.2 Speed Control Circuits 7.2.1 The principles of speed-regulating and control 7.2.2 Throttle speed-regulating circuits by a invariable displacement pump 7.2.3 Volume speed-regulating circuits 7.2.4 Fast-speed movement circuits 7.2.5 Speed shift circuit 7.2.1 The principles of speed-regulating and control 1. Inlet throttle speed-regulating circuits （1）The features of speed-load The formula（7-5）is the speed-load performance equation, the characteristic curves of the speed-load are shown in Fig. 7-8. The character of speed variation with load can be described by speed rigidity as below, (2) Performance of power 3. Bypass throttle orifice speed-regulating circuits (1) Performance of speed-load (2) Characters of power 4.The comparisons for three throttle speed-regulating circuits （4）The comparisons of three circuits in power loss . There is only the throttle orifice loss without the overflow loss. So the bypass circuit has the advantage of lower power loss and higher efficiency tha