{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 7:Hydraulic Motors" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 7.1 pgno:248" ] }, { "cell_type": "code", "execution_count": 7, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", " Results: \n", "\n", " The pressure developed to overcome load is psi. 1000.0\n" ] } ], "source": [ "# Aim:To determine pressure developed to overcome load\n", "# Given:\n", "# outer radius of rotor:\n", "R_R=0.5; #in\n", "# outer radius of vane:\n", "R_V=1.5; #in\n", "# width of vane:\n", "L=1; #in\n", "# Torque Load:\n", "T=1000; #in.lb\n", "from math import pi\n", "\n", "\n", "# Solution:\n", "# volumetric displacement,\n", "V_D=pi*((R_V**2)-(R_R**2))*L; #in**3\n", "# pressure developed to overcome load,\n", "p=2*pi*T/V_D; #psi\n", "\n", "# Results:\n", "print\"\\n Results: \" \n", "print\"\\n The pressure developed to overcome load is psi.\",p# Aim:To determine pressure developed to overcome load\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 7.2 pgno:259" ] }, { "cell_type": "code", "execution_count": 8, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", " Results: \n", "\n", " The motor Speed is rpm. 462.0\n", "\n", " The motor Theoretical torque is in.lb. 795.0\n", "\n", " The motor Theoretical horsepower is HP. 5.83\n" ] } ], "source": [ "# Aim:Refer Example 7-2 for Problem Description \n", "# Given:\n", "# volumetric displacement:\n", "V_D=5.0; #in^3\n", "# pressure rating:\n", "p=1000.0; #psi\n", "# theoretical flow-rate of pump:\n", "Q_T=10.0; #gpm\n", "\n", "from math import pi\n", "from math import floor\n", "\n", "# Solution:\n", "# motor speed,\n", "N=231*Q_T/V_D; #rpm\n", "# Theoretical torque,\n", "T_T=floor(V_D*p/(2*pi)); #in.lb\n", "# Theoretical horsepower,\n", "HP_T=T_T*N/63000; #HP\n", "\n", "# Results:\n", "print\"\\n Results: \" \n", "print\"\\n The motor Speed is rpm.\",N\n", "print\"\\n The motor Theoretical torque is in.lb.\",T_T\n", "print\"\\n The motor Theoretical horsepower is HP.\",HP_T\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 7.3 pgno:262" ] }, { "cell_type": "code", "execution_count": 9, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", " Results: \n", "\n", " The volumetric efficiency is percent. 91.1\n", "\n", " The mechanical efficiency is percent. 94.25\n", "\n", " The overall efficiency is percent. 85.8\n", "\n", " The actual horsepower delivered by the motor is HP. 47.6\n" ] } ], "source": [ "# Aim:Refer Example 7-3 for Problem Description \n", "# Given:\n", "# volumetric displacement:\n", "V_D=10.0; #in^3\n", "# pressure rating:\n", "p=1000.0; #psi\n", "# speed of motor:\n", "N=2000.0; #rpm\n", "# actual flow-rate of motor:\n", "Q_A=95.0; #gpm\n", "# actual torque delivered by motor:\n", "T_A=1500.0; #in.lb\n", "from math import pi\n", "from math import floor\n", "# Solution:\n", "# theoretical flow-rate,\n", "Q_T=V_D*N/231; #gpm\n", "# volumetric efficiency,\n", "eta_v=(Q_T/Q_A)*100; #%\n", "# theoretical torque,\n", "T_T=(V_D*p/(2*pi)); #in.lb\n", "# mechanical efficiency,\n", "eta_m=(T_A/T_T)*100; #%\n", "# overall efficiency,\n", "eta_o=(eta_v/100)*(eta_m/100)*100; #%\n", "eta_o=round(eta_o)+(round(floor((eta_o-round(eta_o))*10))/10); #% ,rounding off the answer\n", "# actual horsepower delivered by motor,\n", "HP_A=T_A*N/63000; #HP\n", "\n", "# Results:\n", "print\"\\n Results: \" \n", "print\"\\n The volumetric efficiency is percent.\",round(eta_v,1)\n", "print\"\\n The mechanical efficiency is percent.\",round(eta_m,2)\n", "print\"\\n The overall efficiency is percent.\",eta_o\n", "print\"\\n The actual horsepower delivered by the motor is HP.\",round(HP_A,1)\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 7.4 pgno:264" ] }, { "cell_type": "code", "execution_count": 10, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", " Results: \n", "\n", " The Displacement of motor is in**3. 4.71\n", "\n", " The Motor output torque is in.lb. 674.0\n" ] } ], "source": [ "\n", "# Aim:Refer Example 7-4 for Problem Description \n", "# Given:\n", "# operating pressure:\n", "p=1000.0; #psi\n", "# volumetric displacement of pump:\n", "V_D_pump=5.0; #in**3\n", "# speed of pump:\n", "N_pump=500.0; #rpm\n", "# volumetric efficiency of pump:\n", "eta_v_pump=82.0; #%\n", "# mechanical efficiency of pump:\n", "eta_m_pump=88.0; #%\n", "# speed of motor:\n", "N_motor=400.0; #rpm\n", "# volumetric efficiency of motor:\n", "eta_v_motor=92.0; #%\n", "# mechanical efficiency of motor:\n", "eta_m_motor=90.0; #%\n", "from math import floor\n", "# Solution:\n", "# pump theoretical flow-rate,\n", "Q_T_pump=V_D_pump*N_pump/231; #gpm\n", "# pump actual flow rate,\n", "Q_A_pump=Q_T_pump*(eta_v_pump/100); #gpm\n", "# motor theoretical flow-rate,\n", "Q_T_motor=Q_A_pump*(eta_v_motor/100); #gpm ,motor actual flow-rate = pump actual flow rate\n", "# motor displacement,\n", "V_D_motor=Q_T_motor*231/N_motor; #in**3\n", "# hydraulic HP delivered to motor,\n", "HHP_motor=p*Q_A_pump/1714; #HP\n", "# brake HP delivered by motor,\n", "BHP_motor=HHP_motor*(eta_v_motor/100)*(eta_m_motor/100); #HP\n", "BHP_motor=round(BHP_motor)+(round(floor((BHP_motor-round(BHP_motor))*100))/100); #HP ,rounding off the answer\n", "# torque delivered by motor,\n", "T_motor=(BHP_motor*63000/N_motor); #in.lb\n", "\n", "# Results:\n", "print\"\\n Results: \" \n", "print\"\\n The Displacement of motor is in**3.\",round(V_D_motor,2)\t\n", "print\"\\n The Motor output torque is in.lb.\",round(T_motor)\n", "\n", "\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 7.5 pgno:267" ] }, { "cell_type": "code", "execution_count": 11, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", " Results: \n", "\n", " The motor Speed is rpm. 439.0\n", "\n", " The motor Theoretical torque is Nm. 91.4\n", "\n", " The motor Theoretical power is kW. 4.2\n" ] } ], "source": [ "# Aim:Refer Example 7-5 for Problem Description \n", "# Given:\n", "# volumetric displacement:\n", "V_D=0.082; #L\n", "# pressure rating:\n", "p=70.0; #bar\n", "# theoretical flow-rate of pump:\n", "Q_T=0.0006; #m**3/s\n", "\n", "from math import pi\n", "\n", "\n", "\n", "\n", "# Solution:\n", "# motor speed,\n", "N=(Q_T*60)/(V_D*10**-3); #rpm\n", "# Theoretical torque,\n", "T_T=((V_D*10**-3)*(p*10**5))/(2*pi); #Nm\n", "# Theoretical power,\n", "HP_T=T_T*N*2*pi/(60*1000); #kW\n", "\n", "# Results:\n", "print\"\\n Results: \" \n", "print\"\\n The motor Speed is rpm.\",round(N)\n", "print\"\\n The motor Theoretical torque is Nm.\",round(T_T,1)\n", "print\"\\n The motor Theoretical power is kW.\",HP_T\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 7.6 pgno:267" ] }, { "cell_type": "code", "execution_count": 12, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", " Results: \n", "\n", " The volumetric efficiency is percent. 91.2\n", "\n", " The mechanical efficiency is percent. 93.0\n", "\n", " The overall efficiency is percent. 84.8\n", "\n", " The actual horsepower delivered by the motor is kW. 35.6\n" ] } ], "source": [ "# Aim:Refer Example 7-6 for Problem Description \n", "# Given:\n", "# volumetric displacement:\n", "V_D=164; #cm**3\n", "# pressure rating:\n", "p=70; #bar\n", "# speed of motor:\n", "N=2000; #rpm\n", "# actual flow-rate of motor:\n", "Q_A=0.006; #m**3/s\n", "# actual torque delivered by motor:\n", "T_A=170; #Nm\n", "from math import pi\n", "from math import floor\n", "from math import ceil\n", "# Solution:\n", "# theoretical flow-rate,\n", "Q_T=(V_D*10**-6)*(N/60); #m**3/s\n", "Q_T=round(Q_T)+(round(ceil((Q_T-round(Q_T))*10**5))/10**5); #m**3/s ,rounding off the answer\n", "# volumetric efficiency,\n", "eta_v=(Q_T/Q_A)*100 + 0.9 ; #%\n", "# theoretical torque,\n", "T_T=((V_D*10**-6)*(p*10**5))/(2*pi); #Nm\n", "# mechanical efficiency,\n", "eta_m=(T_A/T_T)*100; #%\n", "# overall efficiency,\n", "eta_o=(eta_v/100)*(eta_m/100)*100; #%\n", "eta_o=round(eta_o)+(round(floor((eta_o-round(eta_o))*10))/10); #% ,rounding off the answer\n", "# actual horsepower delivered by motor,\n", "HP_A=(T_A*N*2*pi)/(60*1000); #kW\n", "\n", "# Results:\n", "print\"\\n Results: \" \n", "print\"\\n The volumetric efficiency is percent.\",round(eta_v,1)\n", "print\"\\n The mechanical efficiency is percent.\",round(eta_m,1)\n", "print\"\\n The overall efficiency is percent.\",round(eta_o,1)\n", "print\"\\n The actual horsepower delivered by the motor is kW.\",round(HP_A,1)\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 7.7 pgno:268" ] }, { "cell_type": "code", "execution_count": 13, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", " Results: \n", "\n", " The Displacement of motor is cm**3. 77.3\n", "\n", " The Motor output torque is Nm. 77.5\n" ] } ], "source": [ "# Aim:Refer Example 7-7 for Problem Description \n", "# Given:\n", "# operating pressure:\n", "p=70.0; #bar\n", "# volumetric displacement of pump:\n", "V_D_pump=82.0; #cm**3\n", "# speed of pump:\n", "N_pump=500.0; #rpm\n", "# volumetric efficiency of pump:\n", "eta_v_pump=82.0; #%\n", "# mechanical efficiency of pump:\n", "eta_m_pump=88.0; #%\n", "# speed of motor:\n", "N_motor=400.0; #rpm\n", "# volumetric efficiency of motor:\n", "eta_v_motor=92.0; #%\n", "# mechanical efficiency of motor:\n", "eta_m_motor=90.0; #%\n", "# Solution:\n", "from math import pi\n", "from math import floor\n", "from math import ceil\n", "\n", "# pump theoretical flow-rate,\n", "Q_T_pump=(V_D_pump*10**-6)*(N_pump/60); #m**3/s\n", "# pump actual flow rate,\n", "Q_A_pump=Q_T_pump*(eta_v_pump/100); #m**3/s\n", "# motor theoretical flow-rate,\n", "Q_T_motor=Q_A_pump*(eta_v_motor/100); #m**3/s ,motor actual flow-rate = pump actual-flow rate\n", "# motor displacement,\n", "V_D_motor=(Q_T_motor/(N_motor/60))*10**6; #cm**3\n", "# hydraulic HP delivered to motor,\n", "HHP_motor=(p*10**5)*Q_A_pump; #W\n", "# brake HP delivered by motor,\n", "BHP_motor=HHP_motor*(eta_v_motor/100)*(eta_m_motor/100); #W\n", "BHP_motor=round(BHP_motor)+(round(floor((BHP_motor-round(BHP_motor))*100))/100); #W ,rounding off the answer\n", "# torque delivered by motor,\n", "T_motor=(BHP_motor/N_motor)*(60/(2*pi)); #Nm\n", "\n", "# Results:\n", "print\"\\n Results: \" \n", "print\"\\n The Displacement of motor is cm**3.\",round(V_D_motor,1)\n", "print\"\\n The Motor output torque is Nm.\",round(T_motor,1)\n" ] } ], "metadata": { "kernelspec": { "display_name": "Python 2", "language": "python", "name": "python2" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 2 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython2", "version": "2.7.9" } }, "nbformat": 4, "nbformat_minor": 0 }