TORSION 83-2 EXTERNAL TORQUE OF A TRANSMISSION SHAFT INTERNAL TORQUE AND ITS DIAGRAM I\ External torque of a transmission shaft The relation between the transmission power, revolution and external torque of the transmission shaft where: P-power, unit: kilowatt(kW m=9.55(kNm) n rotational speed unit r/min or (rpm) where P-power. unit: horsepower(HP m=7.024(kNm) notational speed, unit: r/min or (rpm where: P-power, unit: kilowatt(kW) m=7.121(kNm) n- rotational speed unit: r/min or (rpm) 1PS=735.5Nm/s,1HP=7457Nms,1kw=1.36PS
11 §3–2 EXTERNAL TORQUE OF A TRANSMISSION SHAFT INTERNAL TORQUE AND ITS DIAGRAM 1、External torque of a transmission shaft The relation between the transmission power, revolution and external torque of the transmission shaft： 9 55 (kNm) n P m . 7 024 (kNm) n P m . 7 121 (kNm) n P m . where：P - power, unit: kilowatt (kW) n – rotational speed, unit: r/min or（rpm） where：P - power, unit: horsepower (HP) n – rotational speed, unit: r/min or（rpm） where：P - power, unit: kilowatt (kW) n – rotational speed, unit: r/min or（rpm） 1PS=735.5N·m/s , 1HP=745.7N·m/s , 1kW=1.36PS
§3-2传动轴的外力偶矩·扭矩及扭矩图 传动轴的外力偶矩 传递轴的传递功率、转数与外力偶矩的关系: P 其中:P一功率,千瓦(kW) m=9.55(kNm) n一转速,转分(rpm) 其中:P一功率,马力(PS) m=7.024-(kNm) n一转速,转分(rpm) m=7121(kNm)共甲:P一功率,马力(HP) n—转速,转/分(rpm) 1PS=7355Nm/s,1HP=745.7Nm/s,lkW=1.36PS12
12 §3–2 传动轴的外力偶矩 · 扭矩及扭矩图 一、传动轴的外力偶矩 传递轴的传递功率、转数与外力偶矩的关系： 9 55 (kNm) n P m . 7 024 (kNm) n P m . 7 121 (kNm) n P m . 其中：P — 功率，千瓦（kW） n — 转速，转/分（rpm） 其中：P — 功率，马力（PS） n — 转速，转/分（rpm） 其中：P — 功率，马力（HP） n — 转速，转/分（rpm） 1PS=735.5N·m/s , 1HP=745.7N·m/s , 1kW=1.36PS
TORSION 2 Internal torque and its diagram 1) Internal torque: The moment of internal forces acting in arbitrary section of the member in torsion designated by t 2) Determine the internal torque by the method of section ∑ m=0,T-m2=0 T -n X 3)Sign conventions for internal torque Twill be considered to be positive when the relation between its turning direction and the out normal line obeys the right hand rule, otherwise it will be considered to be negative
13 3) Sign conventions for internal torque： “T”will be considered to be positive when the relation between its turning direction and the out normal line obeys the right hand rule, otherwise it will be considered to be negative. 2、Internal torque and its diagram 1) Internal torque：The moment of internal forces acting in arbitrary section of the member in torsion. Designated by“T”. 2) Determine the internal torque by the method of section: m m m T T m m T m x 0, 0 x
二、扭矩及扭矩图 1扭矩:构件受扭时,横截面上的内力偶矩,记作“T 2截面法求扭矩 ∑mx=0 T-m=0 T=m 3扭矩的符号规定: “P的转向与截面外法线方向满足右手螺旋规则为正, 反之为负
14 3 扭矩的符号规定： “T”的转向与截面外法线方向满足右手螺旋规则为正， 反之为负。 二、扭矩及扭矩图 1 扭矩：构件受扭时，横截面上的内力偶矩，记作“T” 。 2 截面法求扭矩 m m m T T m T m mx 0 0 x
TORSION 4) Internal torque diagram: Sketch that expresses the law of change of the torque in each cross section along the axis. (1 the law of change of the torque Purpose ② value of z/ Imax and the position of its section→ strength calculation (critical section T x 15
15 4) Internal torque diagram：Sketch that expresses the law of change of the torque in each cross section along the axis. Purpose ① the law of change of the torque ； ②Value of |T|max and the position of its section strength calculation（critical section） x T