2&4 hrow and Firing5 equnnon国要气t大房 2.5.6Flymhoob( 惑购 5 的凡冷大写 窗凡冷大复 Page 5Page 5 37 同济大学汽车学院 • Another example for a V8-engine, throw spacing is 720 ° /8=90 ° • Two cylinders at the same role share the same crank • Firing sequence is 1-8-4-3-6-5-7-2 2.6.4 Throw and Firing Sequences(曲柄及气缸发火顺序) 38 同济大学汽车学院 • Without damping, the excursions of the crank shaft would become increasingly larger until the shaft breaks, therefore, additional measures must be taken, and the only possibility is to reduce the rotational oscillations to a sage level, there are basically two options for this: Damping(减幅) and Absorption（吸收）. • The effect of vibration dampers are based on both damping and absorbing. They are designed to continuously reduce rotational oscillation excursions of the system. • For passenger car engines, rubber vibration dampers are used: the vibration energy is converted by the material damping of the rubber into heat. Two stage dampers are also used in which two damper masses are tuned to two different frequencies. • The dampers not only relieve the crankshaft and camshaft mechanically, but also reduce the play-induced noise of the engine. 2.6.5 Torsion vibration damper(扭转减震器) 39 同济大学汽车学院 • A flywheel is a rotating mechanical device that is used to store rotational energy. It has a significant moment of inertia and thus resists changes in rotational speed. It is often used to provide continuous energy in systems where the energy source is not continuous. • It is used to maintain constant angular velocity of the crankshaft in a reciprocating engine. In this case, the flywheel stores energy when torque is exerted on it by a firing piston, and it releases energy to its mechanical loads when no piston is exerting torque on it, therefore enhance the distribution of the rotation speed and torque output. • Drives the actuator(驱动件) of the clutch（离合器 ） • Flywheels have ring gear at the outer rim of the wheels and is geared with starting motor to start the engine 2.6.6 Flywheels(飞轮)