• SUBJECT-THEORY OF MACHINES.�BRANCH- MECHANICAL ENGINEERING.�SEMESTER- 4^th.�CHAPTER- FOUR.�FACULTY- Er. BARENDRA NATH MOHANTA..�

TOPIC- GOVERNORS & FLYWHEEL

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INTRODUCTION

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• Governor is the device used to control the speed in engines. It is observed that when load is applied on the engine, the speed tends to decrease which is known as rpm drop also, to compensate the speed, governor is used in all stationary or mobile engines which run on either single speed or variable.

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INTRODUCTION

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• A flywheel is a mechanical device that uses conservation of angular momentum to store rotational energy; a form of kinetic energy that is proportional to the product of its moment of inertia and the square of its rotational speed.

TYPE OF GOVERNOR

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• Centrifugal Governor

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*Watt Governor

*Porter Governor

*Proell Governor

*Hartnell Governor

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EQUILIBRIUM SPEED

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• Equilibrium speed of governor: It is the speed at which the governor is in complete balance. The governor balls, sleeve, arms do not tend to move at this speed. Mean equilibrium of governor: it is the speed of governor when the ball or sleeve is in mean position.

WATT GOVERNOR

• Watt governor is the simplest and gravity controlled form of the centrifugal governors. It consists of two fly balls attached to the sleeve of negligible mass. The upper sides of arms are pivoted so that its balls can move upward and downward as they revolve with a vertical spindle. The engine drives the spindle through bevel gears. The lower arms are connected to the sleeves. The sleeve is keyed to the spindle in such a way that revolves with the spindle. At the same time, it can slide up and down according to the spindle speed. Two stoppers are provided at the bottom and top of the spindle to limit the movement sleeve.

WATT GOVERNOR

PORTER GOVERNOR

• The two balls are pivoted at the top so that it can move up and down on a vertical spindle as the speed of revolution of the spindle vary. The lower links are connected to the central sleeve. Vertical sleeve can move up and down along with the ball movements. Two stoppers are provided in spindle to limit the movement of the sleeve. The sleeve is carrying a heavy central load. A mechanism is connected to the sleeve of the governor to actuate the throttle valve.

PORTER GOVERNOR

PROELL GOVERNOR

• Proell governor is a type of gravity controlled centrifugal governor. The centrifugal governor works on the principle of centrifugal force, which gets applicable on the rotating balls. These balls are known as fly balls, which are attached to the spindle through links.

PROELL GOVERNOR

HARTNELL GOVERNOR

• Hartnell governor is a type of spring-loaded centrifugal governor. It is smaller in construction as compared to the dead-weight governor. It consists of a bell crank lever, pivoted to the frame. It has a flyball mounted on a vertical arm & a horizontal arm is inserted into the slot of the sleeve by means of a roller.

HARTNELL GOVERNOR

FLYWHEEL

• Flywheels are often used to provide continuous power output in systems where the energy source is not continuous. For example, a flywheel is used to smooth fast angular velocity fluctuations of the crankshaft in a reciprocating engine. In this case, a crankshaft flywheel stores energy when torque is exerted on it by a firing piston, and returns it to the piston to compress a fresh charge of air and fuel. Another example is the friction motor which powers devices such as toy cars. In unstressed and inexpensive cases, to save on cost, the bulk of the mass of the flywheel is toward the rim of the wheel. Pushing the mass away from the axis of rotation heightens rotational inertia for a given total mass.

CONSTRUCTION

FUNCTION

PURPOSE

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• #1. Engine Balance.
• #2. Engine Start.
• #3. Drivetrain Stress Reduction.
• #4. Engine Speed Soothing.
• #5. Weight Manipulation.

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ADVANTAGES

• The advantages of flywheel energy storage systems are high efficiency, high energy and power density, and long life. On the other hand, flywheels are more expensive and require more space than batteries and fuel cells. There are also some safety concerns about flywheels rotating at high speeds.

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