Design Analysis and Specifications for Mechanical Power Transmission Components

Question 1: Design of Belt Drives (10 marks)
A cross belt drive has two pulleys with radii of 300 mm and 150 mm, respectively, mounted on two parallel
shafts 2.5 + O.P m apart as shown in Figure 1.1 below. Assume that the tight tension, Tl is 1500 + O.P N, the
smaller pulley rotates at 150 + O.P rpm and the frictional coefficient is chosen as 0.20.

As the design engineer, you are required to determine:

1. what the datum lengths of the belts are required for this drive;
2. what the contact angles at two pulleys are; and
3. what is the capacity of power transmission of the belt drive.

Question 2: Design of Chain Drives (10 Marks)
As the design engineer, you are required to specify the required length of no. 60 chain to mount on sprockets
having 15 and 50 teeth, respectively, with a guess centre distance of 40 + O.P pitches, and compute the actual
centre distance.

As shown in Figure 1.2, the chain connects a hydraulic drive with a meat grinder with an input speed 300 + O.P
rpm and an input power 3 + O.P hp. You are also required to

1. Determine what the rating for the two-strand chain; and
2. Design the chain drive according to the input speed and power requirement.

Question 3: Pesien of Snur Gears (10 marks)
A pair of spur gears with 200, full-depth, involute teeth transmits O. 75 + O.P hp as shown in Figure I. 3. The
pinion is on the shaft of an electric motor at + P rpm. The pinion has 24 teeth and
a diametral pitch of 24. The gear has 110 teeth.

As the design engineer. you are required to compute:

• The rotational of the gear
• The velocity ratio and thc gear ratio for the gear pair
• The pitch diameter Of the pinion and the gear
• The centre distance between the shafts carrying the pinion and the gear
• Thc pitch line speed for both the pinion and the gear
• The torque on the pinion shaft and on the gear shaft
• The tangential force acting on the teeth of each gear
• The radial force acting on the teeth of each gear
• The normal force acting on the teeth of each gear

Question 4: Shaft Design (10 marks)
Figure I .4 shows a rotating shaft carrying two steady downward loads F at C and D, respectively and D is right
in the middle between A and B. The shaft is held by a pair of bearings at A and B, respectively. As the design
engineer, you are required to specify a suitable material for material selection by setting up the value of F
using F = 200) + P/100 (N) with a design factor of 2.5 + 0.P.

Question 5: Key Design (10 marks)
Specify a key for a gear to be mounted on a shaft of a 2.50-inch diameter. The gear transmits a torque of 21000+
P lb•in and has a hub length of 4.00 + 0.P in.

As the design engineer, you are required to determine the required key geometry as shown in Figure 1.5:
length, width, and height. Use AISI 1020 cold-drawn steel for the keys if a satisfactory design can be achieved.
If not, use a higher-strength material. Unless otherwise stated, assume that the key material is weakest when
compared with the shaft material or the mating elements.

Are you struggling to keep up with the demands of your academic journey? Don't worry, we've got your back! Exam Question Bank is your trusted partner in achieving academic excellence for all kind of technical and non-technical subjects. Our comprehensive range of academic services is designed to cater to students at every level. Whether you're a high school student, a college undergraduate, or pursuing advanced studies, we have the expertise and resources to support you.

To connect with expert and ask your query click here Exam Question Bank