Go-Kart Brake System Design

This assignment presents a detailed design of a braking system for a go-kart. It includes calculations for brake torque, pedal force, and system pressure, based on given parameters. The design considers the brake pedal ratio, caliper piston diameter, and appropriate seals for the hydraulic system. Sketches of the brake pedal and explanations of different caliper types are also included. The final section presents a PowerPoint presentation outlining the design.

Vehicle Engineering 2

TABLE OF CONTENT
Question 1: Component used in race Kart...................................................................................3
Question 2: Loading across front and rear axle...........................................................................4
Question 3: Force and Torque required.......................................................................................5
Question 4: Sketches of brake pedal............................................................................................6
Question 5: Maximum system pressure.......................................................................................7
Question 6....................................................................................................................................8

Question 1: Component used in race Kart
1. Brake pedal- In Kart braking system, the brake pedal is used to apply the brakes
to the system. If vehicle is moving very fast and it needs to stop, than brake pedal
is used to slow down it's speed, and full pedal is pressed to make it stand still.
2. Brake rod- This is used in hydraulic braking system, where when the brake pedal
is pressed, this push rod, or brake rod is move backward. It apply force on the
piston, which is in master cylinder. This causes the brake fluid to flow into a
pressure chamber, via a compensating port. The pressure will be increased after
that, which apply force to brake pads, and this cause to vehicle to slow down and
then stop.
3. Brake and Band- This can be a primary or secondary brake, which is having band
of different friction material, which gets tightens around a cylinder piece of
equipment. This will either prevent if from rotating or to slow it down.

4. Brake pin- Most of the component of Kart uses a rubber or plastic shim, which s
around the mounting bolts of the caliper. During the continuous friction of brake
pads with the wheel, these pins will get deform, protecting the friction pad.
5. Extension spring- These springs are used at the ends of brake pads. These are
tightly collided springs, which are particularly designed to resist a force, tensile or
stretching. If the spring is pulled outside, this will again tend to go at its initial
position. If the spring is stretched further, its resistance will increase.
6. Brake cable- This is a cable, which connects brake handle, lever or pedal to the
vehicle's braking mechanism.
Braking is very important aspect of vehicle, as these are used in stopping the vehicle. To stop the
vehicle from motion to rest, brakes are used. In go-kart, according to the international standard,
hydraulic brakes are used. Kart will have only single rear axle, which can be use in the
transmission of power from engine to wheel.
Question 2: Loading across front and rear axle
We assume that The center of gravity at front and rear axle is same, because it was not
given separately.
Equation for kinetic energy = E= ½ M v^2
E = ½ 265*9.8
E = 1298.5 Joule
Work done in bringing the vehicle to rest
Ew = F * x
x = distance travelled
F = average brake force
Ew = work done (Joule)
Average brake force can be calculated, when the work done by the brakes will be equal to
the kinetic energy of the vehicle, i.e.
E = Ew
½ M V^2 = F.x
therefore,
average brake force = F = MV^2 / 2*x
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So,
the weight distribution on front and rear axle will be same, which can be given as
w = (W*Cg)/Wb
where, w= distributed weight
W= total weight
Cg=center of gravity
Wb= wheel base
therefore,
w= (265*0.28)/1.7
w= 43.64 kg (on each axle)
Question 3: Force and Torque required
Braking force = Mass * acceleration
F = 265*0.45*9.81
F = 1169.84 N
It can be calculated from another formula, which can be given as,
N = m*g*c
where N= normal force on each tire caused by weight
m= mass to kart
g= gravitational acceleration
c= weight distributed
N(rear)= 265*9.8*0.38
N(rear)= 987.867 Newton
N(front)= 265*9.81*0.62
N(front)= 1611.783 Newton
f(rear)= μ*N (rear)
f(rear)= 0.45*987.867
f(rear)= 444.54 N
here f= frictional force
to find out the acceleration
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a= f(rear)/m
a= 444.54/265
a = 1.67 m/sec
Brake torque = Brake force*effective radius of rotor
= 1169.84*0.15 (radius of Tyre outer dia)
Brake torque = 175.476 Nm
Question 4: Sketches of brake pedal
The brake pedal ratio of front to rear axle is almost same in all the design of go kart. That
is 4:1.
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Question 5: Maximum system pressure
System pressure can be calculated as
Brake pressure= (pedal ratio*pedal force)/area of cylinder
pedal ratio generally taken as 4:1, the braking force = 1169.84 N, area of cylinder= 160 mm
Brake pressure = 4*1169.84/16*10^-2
= 2.92 Mpa
Caliper piston diameter = The ratio or the difference between the master cylinder diameter and
the bore diameter of the wheel is known as caliper piston diameter.
a) Master cylinder diameter = it will be dependent on the required torque of the vehicle.
The effective torque required will be = r*f
where r – effective radius of rotor
f – applied force
The standard size is around 180-200 mm.
The diameter is also dependent on the calculation and its outcome. The weight of the kart also
have an impact on the size of the diameter. If the weight of the kart is 200 kg, including the mass
of the driver, then the disc size of 200 mm will be very much sufficient.
Here, the combined weight is 265 kg, so the master cylinder diameter will be around 180-
200 mm.
b) Caliper piston diameter- There are normally three types of caliper, they are floating caliper,
sliding caliper, fixed caliper.
The sliding caliper or floating caliper will prevent vibration but fixed caliper will cause
vibration. The caliper diameter will totally dependent on the size of master cylinder diameter.
This will be calculated by = 3.14 * (radius of piston)^2 * (half the number of piston)
= 3.14 * 0.2^2* 2
= 2.5 sq inches of the area of the piston.
c) Appropriate seals – For go kart, the system is hydraulic braking system, and for that there are
some types of seals which are present in the market like;
1. Hydraulic piston seals: These are used to seal the fluid which is leaking.
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2. Hydraulic rod seals: They are used in the hydraulic cylinder to fluid sealing.
3. Scrapper rings: These seals prevent the contamination. Used to prevent damage to
wear rings, seals and its other components.
For go kart, for our design, we are using the hydraulic piston seals. As the cooling fluid is all
around the piston area, so we do not want that this fluid will leak from the bottom part of the
piston, that is why we are using piston seals.
Question 6
Enclosed in power point presentation.
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