Hartnell Governor MCQ Quiz - Objective Question with Answer for Hartnell Governor - Download Free PDF

Explanation:

Analysis of Governor Spring Stiffness:

• In a spring-loaded Hartnell governor, the spring stiffness plays a crucial role in determining the governor's performance characteristics.
• The primary function of the governor is to maintain a constant engine speed by adjusting the fuel supply in response to varying loads.
• The governor achieves this by controlling the position of the throttle valve through the movement of the governor sleeve, which is actuated by the centrifugal force of the rotating flyweights and the opposing force of the governor spring.

When the spring stiffness in a Hartnell governor is increased, the following effects on governor performance can be observed:

• Decreased Sensitivity: Sensitivity refers to the governor's ability to respond to small changes in engine speed. A more sensitive governor can detect and correct minor speed variations quickly. Increasing the spring stiffness requires a larger force to move the governor sleeve, which means that smaller changes in engine speed will not produce enough centrifugal force to overcome the stiffer spring. As a result, the governor becomes less responsive to minor speed fluctuations, decreasing its sensitivity.
• Operating Speed Range: The operating speed range of the governor is the range of engine speeds over which the governor can effectively control the throttle position. By increasing the spring stiffness, the governor's operating speed range is expanded. This is because a stiffer spring requires a higher centrifugal force to achieve the same sleeve movement, thus allowing the governor to function over a broader range of speeds.
• Stability: Stability refers to the governor's ability to maintain a steady engine speed without oscillations or hunting. While a stiffer spring can improve the stability by providing a more substantial opposing force to the flyweights, it can also lead to less precise control at lower speeds, potentially causing instability if the governor is not correctly tuned for the engine's operating conditions.
• Wear and Tear: Increasing the spring stiffness does not directly make the governor more susceptible to wear and tear. However, it can result in higher forces acting on the governor components, which may indirectly contribute to increased wear over time if the governor is subjected to frequent adjustments or rapid speed changes.

Explanation: 

• If the stiffness of the spring is increased then the governor will be less sensitive.
• A governor is said to be sensitive when it readily responds to a small change of speed.
• Consider two governors A and B running at the same speed.
• When this speed increases or decreases by a certain amount, the lift of the sleeve of governor A is greater than the lift of the sleeve of governor B.
• It is then said that governor A is more sensitive than the governor B.

Hunting

• Sensitiveness of a governor is a desirable quality. However, if a governor is too sensitive, it may fluctuate continuously.
• This phenomenon of fluctuation is pronounced as hunting.

\(Stiffness\;of\;Hartnell\;Governor\;\left( S \right) = 2 \times {\left( {\frac{a}{b}} \right)^2} \times \left( {\frac{{{F_2} - {F_1}}}{{{r_2} - {r_1}}}} \right)\)

\(Sensitiveness = \frac{{2 \times \left( {{N_2} - {N_1}} \right)}}{{{N_1} + {N_2}}}\)

Explanation:

Governors are classified as:

• Centrifugal Governor
• Inertia Governor

Centrifugal Governors are classified as:

• Dead Weight Governors:
  • Porter governor
  • Proell governor
• Spring controlled governors:
  • Hartnell governor
  • Hartung governor
  • Pickering governor

Hartnell governor 

• Wilson-Hartnell governor (also known as radial spring controller) uses two parallel springs along with an auxiliary spring. This type of governor has a primary/ main spring and an auxiliary spring.
• The main spring is arranged symmetrically on either side of the axis and it connects two flying balls on the vertical arms of the bell crank lever.
• An adjustable auxiliary spring is attached to the sleeve mechanism of the governor through a pivoted lever. 
• The Purpose of this auxiliary spring is that to adjust the equilibrium speed for a given radius of rotation.
• The auxiliary spring tends to keep the sleeve down.

Explanation:-

• The function of the governor is to maintain the speed of an engine within specified limits whenever there Is a variation of loads.
• The operation of a flywheel is continuous whereas that of a governor is more or less intermittent.

Classification of governors

Hartnell governor 

• A Hartnell governor is a/an spring-loaded governor.
• Wilson-Hartnell governor (also known as radial spring controller) uses two parallel springs along with an auxiliary spring. 
• This type of governor has a primary/ main spring and an auxiliary spring.
• The main spring is arranged symmetrically on either side of the axis and it connects two flying balls on the vertical arms of the bell crank lever.
• An adjustable auxiliary spring is attached to the sleeve mechanism of the governor through a pivoted lever. 
• The Purpose of this auxiliary spring is that to adjust the equilibrium speed for a given radius of rotation.
• The auxiliary spring tends to keep the sleeve down.

• Pickering governor used in a gramophone.
• The controlling force curve is a parabolic curve in the case of a dead weight governor.
• The controlling force curve is a straight line in the case of a spring-loaded governor.

Explanation:-

• The function of the governor is to maintain the speed of an engine within specified limits whenever there Is a variation of loads.
• The operation of a flywheel is continuous whereas that of a governor is more or less intermittent.

Classification of governors

Hartnell governor 

• A Hartnell governor is a/an spring-loaded governor.
• Wilson-Hartnell governor (also known as radial spring controller) uses two parallel springs along with an auxiliary spring. 
• This type of governor has a primary/ main spring and an auxiliary spring.
• The main spring is arranged symmetrically on either side of the axis and it connects two flying balls on the vertical arms of the bell crank lever.
• An adjustable auxiliary spring is attached to the sleeve mechanism of the governor through a pivoted lever. 
• The Purpose of this auxiliary spring is that to adjust the equilibrium speed for a given radius of rotation.
• The auxiliary spring tends to keep the sleeve down.

Important Points 

• Pickering governor used in a gramophone.
• The controlling force curve is a parabolic curve in the case of a dead weight governor.
• The controlling force curve is a straight line in the case of a spring-loaded governor.

Explanation: 

Sensitiveness:

• Consider two governors A and B running at the same speed
• When this speed increases or decreases by a certain amount, the lift of the sleeve of governor A is greater than the lift of the sleeve of governor B
• It is then said that governor A is more sensitive than the governor B.
• In general, the greater the lift of the sleeve corresponding to a given fractional change in speed, the greater is the sensitiveness of the governor
• The sensitiveness is defined as the ratio of the difference between the maximum and minimum equilibrium speeds to the mean equilibrium speed.
• The movement of the sleeve for a fractional change of speed is the measure of sensitivity.

\({\rm{Sensitiveness = }}\frac{{{\rm{Range}}\,{\rm{of}}\,{\rm{Speed}}}}{{{\rm{Mean}}\,{\rm{Speed}}}} = \frac{{{\omega _{\max }}\;-\;{\omega _{\min }}}}{{{\omega _{{\mathop{\rm m}\nolimits} ean}}}}=\frac{N_2\;-\;N_1}{N}\)

Hartnell Governor:

In this type of governor, the balls are controlled by spring as shown in the figure.

• For a given stiffness of spring, as the speed increases, the balls move away from the spindle axis and if the speed decreases, the balls moves towards the spindle axis.
• If the stiffness is lowered, then the resisting force of spring will decrease and the balls will be moving more away from the spindle axis i.e. the movement of the sleeve for a fractional change of speed get increase, thus increasing its sensitiveness.

Explanation:-

• The function of the governor is to maintain the speed of an engine within specified limits whenever there Is a variation of loads.
• The operation of a flywheel is continuous whereas that of a governor is more or less intermittent.

Classification of governors

Hartnell governor 

• Wilson-Hartnell governor (also known as radial spring controller) uses two parallel springs along with an auxiliary spring. This type of governor has a primary/ main spring and an auxiliary spring.
• The main spring arranged symmetrically on either side of the axis and it connects two flying balls on the vertical arms of bell crank lever.
• An adjustable auxiliary spring is attached to sleeve mechanism of governor through a pivoted lever. 
• The Purpose of this auxiliary spring is that to adjust the equilibrium speed for a given radius of rotation.
• The auxiliary spring tends to keep sleeve down.

• Pickering governor used in a gramophone.
• The controlling force curve is a parabolic curve in the case of a dead weight governor.
• The controlling force curve is a straight line in the case of a spring-loaded governor.

Explanation:-

• The function of the governor is to maintain the speed of an engine within specified limits whenever there Is a variation of loads.
• The operation of a flywheel is continuous whereas that of a governor is more or less intermittent.

Classification of governors

Hartnell governor 

• A Hartnell governor is a/an spring-loaded governor.
• Wilson-Hartnell governor (also known as radial spring controller) uses two parallel springs along with an auxiliary spring. 
• This type of governor has a primary/ main spring and an auxiliary spring.
• The main spring is arranged symmetrically on either side of the axis and it connects two flying balls on the vertical arms of the bell crank lever.
• An adjustable auxiliary spring is attached to the sleeve mechanism of the governor through a pivoted lever. 
• The Purpose of this auxiliary spring is that to adjust the equilibrium speed for a given radius of rotation.
• The auxiliary spring tends to keep the sleeve down.

Important Points 

• Pickering governor used in a gramophone.
• The controlling force curve is a parabolic curve in the case of a dead weight governor.
• The controlling force curve is a straight line in the case of a spring-loaded governor.

Concept:

Governors are classified as:

• Centrifugal Governor
• Inertia Governor

Centrifugal Governors are classified as:

• Dead Weight Governors:
  • Porter governor
  • Proell governor
• Spring controlled governors:
  • Hartnell governor
  • Hartung governor
  • Pickering governor

Explanation: 

• If the stiffness of the spring is increased then the governor will be less sensitive.
• A governor is said to be sensitive when it readily responds to a small change of speed.
• Consider two governors A and B running at the same speed.
• When this speed increases or decreases by a certain amount, the lift of the sleeve of governor A is greater than the lift of the sleeve of governor B.
• It is then said that governor A is more sensitive than the governor B.

Hunting

• Sensitiveness of a governor is a desirable quality. However, if a governor is too sensitive, it may fluctuate continuously.
• This phenomenon of fluctuation is pronounced as hunting.

\(Stiffness\;of\;Hartnell\;Governor\;\left( S \right) = 2 \times {\left( {\frac{a}{b}} \right)^2} \times \left( {\frac{{{F_2} - {F_1}}}{{{r_2} - {r_1}}}} \right)\)

\(Sensitiveness = \frac{{2 \times \left( {{N_2} - {N_1}} \right)}}{{{N_1} + {N_2}}}\)

Explanation:

Governors are classified as:

• Centrifugal Governor
• Inertia Governor

Centrifugal Governors are classified as:

• Dead Weight Governors:
  • Porter governor
  • Proell governor
• Spring controlled governors:
  • Hartnell governor
  • Hartung governor
  • Pickering governor

Hartnell governor 

• Wilson-Hartnell governor (also known as radial spring controller) uses two parallel springs along with an auxiliary spring. This type of governor has a primary/ main spring and an auxiliary spring.
• The main spring is arranged symmetrically on either side of the axis and it connects two flying balls on the vertical arms of the bell crank lever.
• An adjustable auxiliary spring is attached to the sleeve mechanism of the governor through a pivoted lever. 
• The Purpose of this auxiliary spring is that to adjust the equilibrium speed for a given radius of rotation.
• The auxiliary spring tends to keep the sleeve down.

Explanation:-

• The function of the governor is to maintain the speed of an engine within specified limits whenever there Is a variation of loads.
• The operation of a flywheel is continuous whereas that of a governor is more or less intermittent.

Classification of governors

Hartnell governor 

• A Hartnell governor is a/an spring-loaded governor.
• Wilson-Hartnell governor (also known as radial spring controller) uses two parallel springs along with an auxiliary spring. 
• This type of governor has a primary/ main spring and an auxiliary spring.
• The main spring is arranged symmetrically on either side of the axis and it connects two flying balls on the vertical arms of the bell crank lever.
• An adjustable auxiliary spring is attached to the sleeve mechanism of the governor through a pivoted lever. 
• The Purpose of this auxiliary spring is that to adjust the equilibrium speed for a given radius of rotation.
• The auxiliary spring tends to keep the sleeve down.

• Pickering governor used in a gramophone.
• The controlling force curve is a parabolic curve in the case of a dead weight governor.
• The controlling force curve is a straight line in the case of a spring-loaded governor.

Concept:

Spring stiffness (K) for a Hartnell governor is,

\(K = 2{\left( {\frac{a}{b}} \right)^2}\left( {\frac{{{F_2} - {F_1}}}{{{r_2} - {r_1}}}} \right)\)

Calculation:

Given, For a Hartnell governor,

Mass of each ball (m) = 2.5 kg

Maximum centrifugal force (F2) = 2000 N

Minimum centrifugal force (f1) = 100 N

Max. Radius of ball (r2) = 20 cm

Min. radius of ball (r1) = 15 cm and

Lengths of vertical and horizontal arms of the bell-crank levers are the same i.e., a = b

Spring stiffness (k) for a Hartnell governor is,

\(k = 2{\left( {\frac{a}{b}} \right)^2}\left( {\frac{{{F_2} - {F_1}}}{{{r_2} - {r_1}}}} \right)\)

\(k = 2{\left( 1 \right)^2}\left( {\frac{{2000 - 100}}{{20 - 15}}} \right)\)

∴ K = 760 N/cm

Nearest option is 800 N/cm

Explanation: 

Sensitiveness:

• Consider two governors A and B running at the same speed
• When this speed increases or decreases by a certain amount, the lift of the sleeve of governor A is greater than the lift of the sleeve of governor B
• It is then said that governor A is more sensitive than the governor B.
• In general, the greater the lift of the sleeve corresponding to a given fractional change in speed, the greater is the sensitiveness of the governor
• The sensitiveness is defined as the ratio of the difference between the maximum and minimum equilibrium speeds to the mean equilibrium speed.
• The movement of the sleeve for a fractional change of speed is the measure of sensitivity.

\({\rm{Sensitiveness = }}\frac{{{\rm{Range}}\,{\rm{of}}\,{\rm{Speed}}}}{{{\rm{Mean}}\,{\rm{Speed}}}} = \frac{{{\omega _{\max }}\;-\;{\omega _{\min }}}}{{{\omega _{{\mathop{\rm m}\nolimits} ean}}}}=\frac{N_2\;-\;N_1}{N}\)

Hartnell Governor:

In this type of governor, the balls are controlled by spring as shown in the figure.

• For a given stiffness of spring, as the speed increases, the balls move away from the spindle axis and if the speed decreases, the balls moves towards the spindle axis.
• If the stiffness is lowered, then the resisting force of spring will decrease and the balls will be moving more away from the spindle axis i.e. the movement of the sleeve for a fractional change of speed get increase, thus increasing its sensitiveness.

Explanation:-

• The function of the governor is to maintain the speed of an engine within specified limits whenever there Is a variation of loads.
• The operation of a flywheel is continuous whereas that of a governor is more or less intermittent.

Classification of governors

Hartnell governor 

• Wilson-Hartnell governor (also known as radial spring controller) uses two parallel springs along with an auxiliary spring. This type of governor has a primary/ main spring and an auxiliary spring.
• The main spring arranged symmetrically on either side of the axis and it connects two flying balls on the vertical arms of bell crank lever.
• An adjustable auxiliary spring is attached to sleeve mechanism of governor through a pivoted lever. 
• The Purpose of this auxiliary spring is that to adjust the equilibrium speed for a given radius of rotation.
• The auxiliary spring tends to keep sleeve down.

• Pickering governor used in a gramophone.
• The controlling force curve is a parabolic curve in the case of a dead weight governor.
• The controlling force curve is a straight line in the case of a spring-loaded governor.