Calculate the following: 11.1.1 The area of the ram if the diameter of the cylinder is 110 mm - NSC Mechanical Technology Fitting and Machining - Question 11 - 2023 - Paper 1

Using the formula for force:

$f = \frac{F \cdot a}{A}$

Given F = 350 N and A (area of the plunger) = 0.005 m²:

$f = \frac{350 \times 0.005}{0.0095} \approx 184.21 N$

Using the relationship:

$h = \frac{A \cdot H}{a}$

Where H is the area of the ram, and substituting values:

$h = \frac{0.0095 m^2 \cdot 0.025 m}{0.005 m^2} = 0.0475 m = 47.5 mm$

Pressure gauges serve several purposes:

• They help to adjust pressure control valves.
• They allow for determining the pressure being exerted.
• For safety, as they indicate whether pressure limits are being approached.
• They can indicate any leaks present in the system.

One advantage of pneumatics is that pneumatic tools are typically very environmentally friendly due to their clean operation.

To find the rotational frequency of the driven pulley, we use:

$N_{DN} = \frac{N_{DR} \times D_{DR}}{D_{DN}}$

Substituting values:

$N_{DN} = \frac{25 \times 75}{350} \approx 5.36 r/sec$

Using the formula for belt speed:

$V = \frac{D_{DR} \times N_{DR}}{D_{DN}}$

Substituting values:

$V = \frac{0.075 m \times 25}{0.350 m} \approx 5.89 m/s$

The slippage of the V-belt is what protects it against sudden loads, ensuring the belt does not sustain damage.

Using the relationship:

$N_{B} = \frac{product \ of \ teeth \ on \ driven \ gears}{product \ of \ teeth \ on \ driver \ gears} \times N_{A}$

Calculating:

$N_{B} = \frac{30 \times 25}{55 \times 50} \times 95 \approx 25.91 r/min$

The power transmitted is calculated using:

$P = \frac{2 \pi N T}{60}$

Where T = 120 Nm and substituting for the frequency:

$P = \frac{2 \pi \times 95 \times 120}{60} \approx 1193.81 W \approx 1.19 kW$

Using the torque formula:

$T = F \cdot R$

Rearranging to find radius R:

$R = \frac{T}{F} = \frac{135 Nm}{300 N} = 0.45 m \ or \ 450 mm$