Week 4- Engine balance

Question 1

What are the equations for piston velocity and acceleration?

Answer 1

Velocity: rw(sin(wt) + r/2l *sin (2wt))
Acceleration: rw^2 ( cos(wt) + r/l cos(2wt))

Question 2

What are the reciprocal masses in analysis?

Answer 2

Reciprocal masses = Piston mass and Conrod small end mass (piston + conrod) = m_rec

Question 3

What are the rotating masses in analysis?

Answer 3

The crankshaft, and the conrod big end

Question 4

Explain how reciprocating masses with equations for a four-cylinder engine.

Answer 4

Answer on canvas/ one note

Question 5

Derive the balance for the equation, and explain how this is balanced.

Answer 5

F-balance = -0.5 (mp + m_rec) *rw^2 *r/l *cos (2wt),it consists of two masses (auxiliary shafts) rotating at double the rate of the crankshaft, in opposite directions.

Question 6

Explain how a rotating force in the engine can be balanced with two web balancers, and derive the equations.

Answer 6

On canvas

Question 7

What is the centrifugal force equation?

Answer 7

F = m*w^2 *r

Question 8

Derive the equations for an integrated web balance design.Draw the integrated web design.

Answer 8

On canvas

Question 9

Can the reciprocating internal forces cause a moment even if their sum is zero?

Answer 9

Yes

Question 10

What cylinder engines have the best balance

Answer 10

6 cylinder engines have the best balance

Question 11

What happens to torque unevenness as you increase the number of cylinders in the engine?

Answer 11

It decreases, 6 and 8 cylinders have good torque evenness.

Question 12

What is piston slaps?

Answer 12

Piston slaps is where when the piston moves through TDC and changes direction the piston can hit the liner, which is loud.