Flashcards

Question 1

What is a structure that relies of the weight of the material for their strength and support. Typically made with stone, brick, soil and concrete blocks?

Answer 1

Mass structures

Question 2

What are the key features of a mass structure?

Answer 2

They rely on the weight of the material for their strength and support.

Question 3

What are mass structures usually made of?

Answer 3

Stone, brick, soil and concrete blocks

Question 4

What are framed structures?

Answer 4

A structure that is made by connecting individual parts called members of material.

Question 5

What structure is made by connecting individual parts called members?

Answer 5

Framed structures

Question 6

Examples of framed structures

Answer 6

Bridges, roof truss

Question 7

Examples of mass structures

Answer 7

Pyramids, igloos, water dams

Question 8

What structure is made from thin materials to create a hollow structure?

Answer 8

Shell structures

Question 9

What is a shell structure?

Answer 9

A structure made from thin materials that create a hollow structure

Question 10

What are shell structures typically made of?

Answer 10

Sheet steel or plastic

Question 11

Examples of shell structures

Answer 11

A car body, aircraft fuse cage.

Question 12

What structure is naturally formed and grow and erode over time?

Answer 12

Natural structures

Question 13

What are natural structures?

Answer 13

Naturally formed structures that grow and erode over time

Question 14

Examples of natural structures

Answer 14

Skeletons, trees and Grand Canyon.

Question 15

What linkage forms a Z shape

Answer 15

Reverse motion linkages

Question 16

What linkage forms a /-/ shape

Answer 16

Parallel linkages

Question 17

What linkage forms a quarter circle shape

Answer 17

Bell crank linkage

Question 18

Do materials react better when being crushed or being pulled apart?

Answer 18

Crushed

Question 19

What is the rise in a cam?

Answer 19

The part of the cam that causes the follower to rise

Question 20

What is a dwell in a cam?

Answer 20

When the cam rotates but the follower does not rise or fall

Question 21

What is the fall in a cam?

Answer 21

The part of the cam that causes the follower to fall

Question 22

What is one cycle in a cam?

Answer 22

One rotation or revolution of the cam.

Question 23

Does an ellipse cam ever dwell

Answer 23

No

Question 24

Main characteristics of a snail cam

Answer 24

It has a very sharp fall and if put on the wrong way it will break.

Question 25

What are the 4 types of rotation?

Answer 25

Rotary, linear, oscillating, reciprocating

Question 26

What does a displacement diagram show.

Answer 26

It shows the displacement of the cam at different points of rotation.

Question 27

If a driver and driven goes from small to big what happens to the speed and torque

Answer 27

Less speed and more torque.

Question 28

If a driver and driven go from big to small then what happens to the speed and torque

Answer 28

It will have more speed and less torque

Question 29

Velocity ratio diameter

Answer 29

Diameter of driven pulley/diameter of driver pulley

Question 30

Velocity ratio torque

Answer 30

Output torque/input torque

Question 31

Velocity ratio speed

Answer 31

Input speed/ output speed

Question 32

What is the formula for torque

Answer 32

Torque = Force(F) x Distance(M)

Question 33

What are spur gears?

Answer 33

Spur gears are gears that push together when rotating and have teeth .

Question 34

What are the advantages of spur gears?

Answer 34

Slipping doesn’t happen because of the positive drive, less parts required because there is no need for a belt or chain, low cost to get.

Question 35

What are the disadvantages of spur gears?

Answer 35

Suited to low speeds, the gear teeth experience a lot of stress, can’t transfer power between non parallel shafts, make a lot of noise when operating at high speeds.

Question 36

What are gear trains?

Answer 36

A gear train is made up of more than 2 gears.

Question 37

What are idler gears?

Answer 37

An idler gear makes it so that the driver and the driven are rotating the same way.

Question 38

What are compound gears?

Answer 38

A number of gears that are fixed together and rotate at the same speed and share the same shaft.

Question 39

What are bevel gears?

Answer 39

Used to change direction of the drive in the gear system 90 degrees.

Question 40

What is torque in gears?

Answer 40

The turning force when the load F is applied at distance L away from the centre of rotation.

Question 41

What is the equation for torque in gears?

Answer 41

Torque = Force x Distance T = N x mm

Question 42

What measurement is torque expressed in?

Answer 42

Torque is measured in Newton millimetres (Nmm).

Question 43

What is torque determined by

Answer 43

It is determined by the Distance and the Load

Question 44

What is a worm gear?

Answer 44

It is another way of changing the direction of the drive in a gear system 90 degrees. It is powered by a motor.