Engine Governor

Engine Governor

Governor:

A governor, or speed limiter, is a device used to measure and regulate the speed of a machine, such as an engine.

Controlling Force is the inward radial force exerted on each ball of a centrifugal governor by the arms, spring, etc. which are attached to it. At any equilibrium speed the controlling force is equal and opposite to the centrifugal force.Effort is the mean force exerted at the sleeve due to a 1% change in the speed of the governor.Power is the work done at the sleeve for a 1% change in speed. It is called “The Power” and is equal to the effort times the sleeve displacement.Sensitivity is defined as the ratio of the mean speed to the speed range of the governor over its limits of operation.Stability: A governor is said to be stable if there is one equilibrium speed for each radius of rotation  and this speed increases with the radius. i.e.

Isochronism: A governor is said to be isochronous if, neglecting friction, the equilibrium speed is the same for all radii of the balls. This implies infinite sensitivity and the governor will always fly to one or other extreme position.Hunting: The governor is said to hunting if the engine speed is caused to fluctuate continually above and below the mean speed. This is caused by over-compensation of the energy supply due to the governor being too sensitive.

A classic example is the centrifugal governor, also known as the Watt or fly-ball governor on a reciprocating steam engine, which uses the effect of centrifugal force on rotating weights driven by the machine output shaft to regulate its speed by altering the input flow of steam.

Types of Governors:

Inertial Governors

Centrifugal Governors

                      Pendulum Type Gov.

                                                             Watt governor

                     Loaded Type Gov.

                                          Gravity Controlled Gov.

                                                                             Porter Gov.

                                                                             Proell Gov.

                                                          Spring Controlled Gov.

                                                                              Hartnell Gov.

                                                                             Wilson Hartnell Gov.

                                                                             Hartung Gov.

                                                                              Pickering Gov.

HOW DOES A SMALL ENGINE GOVERNOR WORK?

The governor system is like a cruise control system. It maintains the speed of your lawn mower or outdoor power products. When Briggs & Stratton governors are adjusted properly, they keep your speed steady regardless of engine load – the amount of work the engine must perform.