Robotics Structure Design

Report

for

Final
Academic Year 2/2563

Course: 010243106 Robotics Structure Design

Section 1

Student name: Student ID: _____________________

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010243106 Robotics Structure Design Academic year 2/63 1/18

1. What are the advantages and disadvantages of gear drives when compared with
other drives, such as v-belt, timing belt and chain drives? Please describe at least 10
topics. (1 point)
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2. Please write down the gear terminology for each arrow. (1 point)

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010243106 Robotics Structure Design Academic year 2/63 2/18

3. What is the Lewis form factor for gears calculation? What are the parameters
which used for to find the Lewis value? (1 point)
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4. How many types of gear manufacturing processes are there? (1 point)
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5 . Please describe the advantages and disadvantages of helical gear when
compared with spur gear. (1 point)
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010243106 Robotics Structure Design Academic year 2/63 3/18

6. Please reasonable explain and sketch a picture for the suitable gear set which
may be used for an AGV wheel drive. (1 point)
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The following problem used for the questions 7-8.

A 3-stage gear train designed for a power transmission of 37 kW motor. The input
revolutionary speed being 1,450 rpm. The first couple is the helical gears Z1 and Z2 with
a reduction speed ratio i1 is 3. The second couple is also the helical gears Z3 and Z4
with a reduction speed ratio i2 is 5. The last coupler is the spur gears Z5 and Z6 with a
reduction speed ratio i3 is 7. The real gear train shown in Figure 1 and its diagram shown
in Figure 2. Please answer the following questions.

Figure 1. Gear Train

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010243106 Robotics Structure Design Academic year 2/63 4/18

Figure 2. Diagram of Gear Train

7. Please calculation the maximum torque which loading on a shaft of 1, 2, 3 and

4, respectively. (2 points)
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010243106 Robotics Structure Design Academic year 2/63 5/18

8. From the above gear train. The couple of the last spur gears are Z5 and Z6.
Define a normal pressure angle, 

n
is 20 FD (Full Depth). The teeth number of the

pinion must not less than 22. Working condition is a little impact load also. The material
for manufacturing is a grey cast iron ASTM 50. Please find the dimensions of this spur
gear such as module, pitch diameter, width and a center distance between Z5 and Z6
shaft. Must be proof by the dynamic load (Fd) and bending load (Fb). (10 points)
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010243106 Robotics Structure Design Academic year 2/63 6/18

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010243106 Robotics Structure Design Academic year 2/63 7/18

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010243106 Robotics Structure Design Academic year 2/63 8/18

9. If we need to design a mini 6-axis robot arm for pick and place object. Please
define the requirement and specification of mechanical design by yourself as below.

http://pubs.sciepub.com/ajme/3/6/26/index.html

9.1 Functionality (1 point)
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9.2 Reliability (1 point)
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9.3 Motion Range and Speed (1 point)
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010243106 Robotics Structure Design Academic year 2/63 9/18

9.4 Payload (1 point)
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9.5 Reach (1 point)
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9.6 Axes (1 point)
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10. From the topic 9. Please find example of standard parts which can buy
from vendors (at least 10 parts). (1 point)
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010243106 Robotics Structure Design Academic year 2/63 10/18

11. From the topic 9. Please find example of manufacturing parts which may be
fabrication by yourself (at least 10 parts). (1 point)
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12. Please explain why we always use the aluminum alloy for manufacturing the arm
of robot. If we do not use this aluminum alloy. What are other material types that can
be made of these parts? (1 point)
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13. Please describe and show stress equations which generated inside the following

robot parts.
13.1 Robot arm (Cantilever Beam) parts (1 point)
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010243106 Robotics Structure Design Academic year 2/63 11/18

13.2 Screw and nut joints for the fixed joints of robot parts (1 point)
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13.3 Servo motor shafts (1 point)
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13.4 Gripper parts (1 point)
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13.5 Bearings for revolute joint parts (1 point)
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13.6 Gear train of servo motors (1 point)
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010243106 Robotics Structure Design Academic year 2/63 12/18

14. Two plates of cantilever beam robot arm 10 mm thick are joined by a double
riveted lap joint as shown in figure below. The rivets are 5 mm in diameter. Find the
bearing stress induced between the plates and the rivet, if the maximum tensile load P
on the joints is 500 N. (2 points)

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15. For the assembly processes of mini robot arm. Why do we use the screw joint?
Please find the advantages and disadvantages of screw joint compare to other joints such
as rivet joint, welded joint, glue joint. (2 points)
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010243106 Robotics Structure Design Academic year 2/63 13/18

16. An eye bolt is to be used for lifting a load of 100 kN. Find the nominal diameter
(d) of the bolt, if the tensile stress is not to exceed 300 MPa. Assume coarse threads.
An eye bolt for lifting a load is shown in Figure below. The table is in the next 2 pages.

Let d = Nominal diameter of the bolt, and
dc = Core diameter of the bolt.
t = Permissible tensile stress for the bolt material.
We know that external load applied (P), (5 points)

P =


4
(dc

2)t

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010243106 Robotics Structure Design Academic year 2/63 14/18

Table of Design dimensions of screw threads, bolts and nuts according
to IS : 4218 (Part III) 1976 (Reaffirmed 1996), Coarse series.

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(Continuous) Table of Design dimensions of screw threads, bolts and nuts according
to IS : 4218 (Part III) 1976 (Reaffirmed 1996), Coarse series.

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010243106 Robotics Structure Design Academic year 2/63 16/18

17. A single row deep groove ball bearing number 210 (see table below) is used for a
wheel drive of mobile robot. The bearing is to carry a radial load of 5,500 N and an axial
or thrust load of 1,500 N. Assuming light shock load, determine the rating life of the
bearing in the unit of revolution and hours if the average speed of wheel drive is 2,000
rpm. (8 points)

Table of Basic static and dynamic capacities of various types of radial ball bearings.

Table Values of service factor (KS).

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010243106 Robotics Structure Design Academic year 2/63 17/18

Table Values of X and Y for dynamically loaded bearings.

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010243106 Robotics Structure Design Academic year 2/63 18/18

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