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Questions and Answers

A belt drive system requires a heavy capacity belt. What is the smallest pulley diameter that should be used?

125 mm
56 mm
80 mm (correct)
40 mm

If a light capacity belt with a thickness of 1.5 mm is selected for a drive system, what would be a recommendable pulley width that is not available?

10 mm
45 mm (correct)
35 mm
50 mm

An engineer is designing a belt drive system using a medium capacity belt. They want to use the smallest possible pulley diameter according to the provided data. What minimum diameter should they choose?

25 mm
16 mm
40 mm (correct)
56 mm

A belt drive system is being designed with a required inside length of 1100 mm. Which belt cross-sections could be used?

Light, medium, or heavy capacity (C) Signup and view all the answers

A designer needs a belt with an inside length as close as possible to 2100 mm. If only listed belt lengths are available, what is the closest inside length they can select?

2240 mm (C) Signup and view all the answers

For a medium capacity belt system requiring a pulley, which has the smallest recommended diameter possible, what belt width should be considered?

20 mm (C) Signup and view all the answers

An application requires a very short belt. What is the shortest inside length available for a light capacity belt?

200 mm (A) Signup and view all the answers

A system using pulleys with a diameter of 70 mm requires a belt. Based on the data, which belt type(s) could you select?

Medium capacity only (D) Signup and view all the answers

A flat belt drive system has a large pulley with a diameter of 60 cm and a small pulley with a diameter of 20 cm. If the center distance between the pulleys is 100 cm, what is the approximate arc of contact on the smaller pulley, in degrees?

156 (B) Signup and view all the answers

Which of the following is required to calculate the length of the arc of contact?

Pulley diameter and angle of contact (B) Signup and view all the answers

In a flat belt drive system, if the diameter of the pulley is doubled and the angle of contact is halved, what is the effect on the length of the arc?

The arc length remains the same. (D) Signup and view all the answers

If the diameter of a pulley is 230 mm and the angle subtended by the arc of belt contact is 115 degrees, calculate the length of the arc.

230 mm (A) Signup and view all the answers

When should a correction for the arc of contact be considered in flat belt drive calculations?

Especially for the smaller pulley in the system (D) Signup and view all the answers

According to Table 13, what diameter of bolt is typically used with a plate size of '3 small'?

10 mm (A) Signup and view all the answers

For a belt width of 400 mm, which plate size and bolt diameter is recommended according to Table 13?

Size 3 small with 10 mm bolt (C) Signup and view all the answers

What is the primary reason for enclosing a belt drive with covers?

To prevent foreign materials from contacting the drive and for safety. (D) Signup and view all the answers

What aspects of belt drives should be inspected on a periodic basis, according to the provided information?

The tightness of the belts, keys and setscrews, and the condition of the belt. (A) Signup and view all the answers

According to the example calculation, if a small pulley has a diameter of 150 mm and rotates at 1500 rpm, what is the approximate belt speed?

706.86 m/min (A) Signup and view all the answers

In the example of flat rubber belt drive selection, what type of motor is assumed?

A normal-torque squirrel-cage AC motor. (A) Signup and view all the answers

In the provided example calculation, which parameter does 'NS' represent in the belt speed formula?

The speed of the small pulley in revolutions per minute (rpm). (D) Signup and view all the answers

In a crossed belt system, how does increasing the distance between the centers of the pulleys (C) affect the required belt length (L), assuming all other variables remain constant?

L increases linearly with C. (B) Signup and view all the answers

A belt drive system has a large pulley diameter ($D_L$) of 200 mm and a small pulley diameter ($D_S$) of 100 mm. If the available standard belt length ($L_S$) is 1500 mm, which formula would you use to calculate center distance?

$C = (b + \sqrt{b^2 - 32(D_L - D_S)}) / 16$, where $b = 4L_S - 6.28(D_L + D_S)$ (C) Signup and view all the answers

Based on the 'Example of flat rubber belt drive selection,' what belt type is suggested for a pulley diameter of 127 mm and a belt speed of approximately 688 m/min?

A 3 ply, Fabric belt (D) Signup and view all the answers

When designing a belt drive with more than two pulleys, which method is most accurate for determining the required belt length?

Graphically laying out the pulleys to scale and summing the tangent and arc lengths. (D) Signup and view all the answers

In a belt drive system, if you need to increase the power transmission without changing the pulley diameters or the belt material, which of the following adjustments would be most effective according to the content?

Increase the center distance between the pulleys to a practical extent and select a longer belt. (A) Signup and view all the answers

Given a standard belt length ($L_s$), a large pulley diameter ($D_L$), and a small pulley diameter ($D_S$), what does the variable 'b' represent in equation 2?

A term that incorporates the belt length and pulley diameters to calculate center distance. (C) Signup and view all the answers

Which of the following arrangements of flat belts is acceptable for use in agricultural machinery?

Belts spliced to the desired loop size or made as a continuous loop. (D) Signup and view all the answers

A flat belt drive system has a driver pulley rotating at 1200 rpm with a diameter of 150 mm. What calculation determines the belt speed?

Multiply the rpm by the diameter and $\pi$ (pi). (A) Signup and view all the answers

In selecting a flat belt for a grain harvester operating in a humid environment, which material property is most critical?

Resistance to moisture (C) Signup and view all the answers

What is the primary advantage of using rubberized fabric in flat belts for agricultural machinery?

High tensile strength and resistance to moisture (A) Signup and view all the answers

What force would necessitate using a flat belt drive instead of a V-belt or synchronous belt?

Power transmission over fairly long center distances. (B) Signup and view all the answers

If a flat belt system exhibits excessive slippage, what adjustment addresses this issue, assuming proper belt tension?

Apply a specialized belt dressing to enhance friction. (B) Signup and view all the answers

In a flat belt system operating under heavy load, the belt stretches beyond its elastic limit. What is the most likely consequence of this scenario?

Permanent deformation and potential belt failure. (C) Signup and view all the answers

Compared to a traditional flat belt made of rubberized fabric, what advantage does a flat belt reinforced with nylon cords offer?

Increased tensile strength and reduced stretching under load. (B) Signup and view all the answers

According to Table 10, what is the 'F' dimension of a flat pulley when 'A' is 305 mm and 'B' is 203 mm?

13 mm (A) Signup and view all the answers

A flat pulley has dimension 'A' of 457 mm and dimension 'B' of 305 mm. Referring to Table 10, what is its 'H' dimension?

22 mm (A) Signup and view all the answers

If a flat pulley has dimensions 'A' = 254 mm and 'B' = 152 mm, what are the corresponding 'C' and 'G' dimensions according to Table 10?

'C' = 4 mm, 'G' = 89 mm (C) Signup and view all the answers

What is one potential benefit of using larger pulley diameters in belt drives?

The ability to use smaller and less expensive belt cross-sections (A) Signup and view all the answers

What 'E' dimension corresponds to pulley dimensions 'A' = 508 mm and 'B' = 305 mm, as per Table 10?

41 mm (D) Signup and view all the answers

A designer aims to minimize bearing loads in a belt drive system. According to section 6.5, which pulley diameter should they choose?

The largest possible diameter (B) Signup and view all the answers

Based on Table 10, which combination of 'A' and 'B' dimensions results in an 'F' dimension of 32 mm?

'A' = 457 mm, 'B' = 508 mm (A) Signup and view all the answers

A pulley has 'A' dimension of 356 mm and a 'B' dimension of 203 mm. What are the 'C', 'E', and 'H' dimensions for this pulley according to Table 10?

'C' = 5 mm, 'E' = 33 mm, 'H' = 127 mm (B) Signup and view all the answers

Which of the following 'A' dimensions corresponds to the largest 'G' dimension provided in Table 10?

559 mm (C) Signup and view all the answers

Considering both the table and section 6.5, what is the most reasonable approach when selecting a pulley with a specific 'A' dimension if minimizing bearing load is the primary concern?

Choose the pulley with the largest 'B' dimension for that 'A' value to potentially allow for smaller belt cross-sections (A) Signup and view all the answers

Flashcards

Flat Belt

Belts that transmit rotary motion and power between two shafts, lying flat on the pulley face.

Flat Belt Pulley

A wheel with a flat or crowned face used to transmit motion and power using flat belts.

Flat Belt Drive

Power transmission device using flat belts to transmit power and motion between two shafts with flat pulleys.