couplings and flywheels - mercer...
TRANSCRIPT
Couplings and Flywheels
MAE 322
Couplings are divided into categories
• Rigid & Flexible
• Rigid couplings by virtue of their simple rugged design are generally able to transmit more power than flexible couplings of comparable size but this is not an Important advantage except in high horsepower applications.
Shaft Misalignment Compensation
• Angular and Lateral Misalignment are common and always present to some degree.
Flexible Couplings
Universal joint bellows & plain couplings
Shaft Couplings
Shigley’s Mechanical Engineering Design
Fig. 16–26
Flexible Couplings
Bellows coupling
Flywheels
• Energy Storage
– Punch Press
– Baseball pitching machine
• Smooth out fluctuating torque
– Pistons on crank shaft
Flywheels: Torque required to accelerate
Shigley’s Mechanical Engineering Design
Sum of the moment (torque) along the axis= Inertia x angular acceleration.
Hypothetical Flywheel Case: Work & Energy
Shigley’s Mechanical Engineering Design
Fig. 16–27
Kinetic Energy
Shigley’s Mechanical Engineering Design
Engine Torque for One Cylinder Cycle
Shigley’s Mechanical Engineering Design Fig. 16–28
Punch-Press Torque Demand
Shigley’s Mechanical Engineering Design
Fig. 16–29
Coefficient of Speed Fluctuation, Cs
Shigley’s Mechanical Engineering Design
Energy Change
Shigley’s Mechanical Engineering Design
Cs=Coefficient of Speed Fluctuation
More Basic Flywheel Equations
𝐼 = 12𝑀𝑟
2 Mass Moment of Inertia for a solid disk about central axis
Energy change in/out ∆𝐸 = 12𝐼 𝜔
2𝑚𝑎𝑥 − 𝜔2
𝑚𝑖𝑛
Punch-Press Analysis
Shigley’s Mechanical Engineering Design