Chapter 1: Gears⚙
- Rakshan Bathri
- Nov 16, 2024
- 12 min read
Updated: Nov 17, 2024
Chapter 1.1: The Jargon Used
getting our definitions right!
Hello 👋👋
I'm back from my sem break❗❗ This time, I will be writing my blogs about the CPDD module instead of ICPD. (we upgraded) Before I begin with my blog, you're probably going to notice a few changes in my writing style✍ as I now have like actual questions to answer and can't use my creativity to yap🗣🗣 about whatever I want to. (also there might be fewer bolded words because of my haters 💢💢)
Gears⚙
Okay now moving on to the main part of the blog, GEARS❗❗ Before I actually begin telling you about gears, not gonna lie I thought it would be ✨fun✨ because I'm finally doing the engineering part in 🔥Chemical Engineering🔨. Let me elaborate a bit more; Besides doing calculations🤓 and all the other things for my modules, this is the first time that I'm learning something that most engineering courses would do or learn about as well❗(I hope you get what I mean)
Q: "What are gears❓
A: Gears are simply wheels with teeth⚙⚙ that connect to control the movement and speed of machinery. When one gear turns, its teeth grip and turn the next gear, causing both to spin❗❗ It can go ⏩faster or slower⏪ depending on the size and configuration of the gears.
Gears help transfer and change power/torque 💪 between parts in an extremely efficient manner, making them essential in a wide range of moving objects. (I used chatGPT to help me rephrase whatever I originally wrote because my English was dying...)
Gears can be found almost EVERYWHERE you look (at least for me), including cars🚗, bicycles🚴♀️, clocks⏰, and even those electric drills❗ They help control the speed and torque in cars, allowing them to accelerate from a slow start to highway speeds💨. Gears on a bicycle make it easier for us to pedal uphill or down straight roads🤯 For example, when we go uphill, we decrease🔽 the gear so that it does not take that much energy to go up. They're also found in watches and clocks, where tiny gears ensure that the hands move precisely to keep the time accurate❗❗
Time to learn about the Jargon❗
Gear Module (m):
An indication for the size of our gear teeth.
The higher🔼 the value of m, the larger the teeth🦷(and vice versa)
The value of m ✨MUST✨ match the value of the gear it is in contact with.
Pitch Circle:
The imaginary blue circle🔵 you see above.
It's the circle found in the middle of the teeth. (idk how to explain this which is why I drew a picture above)
Pitch Circular Diameter (PCD):
It's the diameter of the Pitch Circle
Number of teeth (Z)
Number of teeth. (just to make sure you know, its the NUMBER of teeth btw, not the size not the diameter but the NUMBER)
Usually, we don't actually count the number of teeth because the gears you see in your cars or bicycles, are quite big and, counting is a hassle😵😵
Q: "What if I need to know the number of teeth❓
A: Use the equation below❗
The majority of the time, the PCD and m are given so that you know if your gear is compatible✨ with the gear train. Using these 2 values, you can get Z and perform some calculations🤓 with it.
Conclusions:
When m increases, PCD increases as the teeth get larger🔼 (they are proportional)
If you want to shop for gears and they don't give you the module, just use the equation above (this might be too specific)
Chapter 1.2: Relationships between Ratios
R & R
Gear Ratios❗
Gear ratios describe the relationship between the sizes✨ and speeds⏩ of the gears that work together.
When you connect a smaller gear to a larger one, each full turn of the smaller gear only moves the larger gear a fraction of a turn, slowing it down while increasing torque🔄 (which is the rotational force produced). This high gear ratio (>1) is used when more power is required, such as in a car when accelerating from a stop or climbing a steep hill🌄, because the engine can turn the wheels with more force, even if it means they rotate slower. (I might be overusing this car analogy too much)
A low gear ratio (<1) occurs when a larger gear drives a smaller one. In this configuration, the smaller driven gear rotates faster than the larger driver gear but produces less torque⏩⏩. This is ideal for high-speed situations, such as cruising on a bike down a straight road🚴♀️🚴♀️. Here, each pedal rotation (driver gear) causes multiple spins of the bike wheel (driven gear), allowing for faster speeds with less effort❗❗ (vroom vroom)
Q: "How do I calculate the gear ratio❓ A: Look at the 2 pictures below❗
🤓☝
T refers to the torque produced by the gear which can be calculated by
T = f x d
f = Perpendicular force applied
d = distance the force has to "travel"
(if you're using a rod connected to the wheel thingy you spin, the amount of force you apply is how much force, f you use to turn the wheel and the distance, d is the length of the rod)
Credits to Yoong Sern for those 2 pictures above❗
(I took it from the group report we had to submit)
Chapter 1.3: Hand Squeezed Fan
fan fan fan fan fan fan fan fan fan fan fan (I'm losing it)
We made a fan❗
Do you see that video there❓YEAH WE MADE THAT❗❗(Cool right?) We were tasked to assemble a hand-squeezed fan using the parts and gears given. This process was honestly quite ✨fun✨ as it was something new to me. If I ever use a handheld fan, most of the time it's those electric ones where you just press a button and the magic happens. But, when we made this, it felt like I was reliving a childhood experience that I never had❗(I hope you get what I mean)
Problems Faced...
Well, even though it does look simple and cute-ish, there were some problems that it had which really made it not fun to use😵
Here are the problems:
The Crank: We had to keep pushing and pulling the fan. What's so bad about it❓ It got tedious and it felt like a waste of my energy😭 for how much the fan actually spins (I'd rather fan myself using paper or my CRE notes)
The Exterior: Why are there so many holes❗❗ it doesn't look sleek at all and the grip is so awkward (It felt like I was pinching the fan) This made me look like I was a toddler playing with a toy 😠
Quality: I'm fine with the gears being plastic but this time, EVERYTHING is plastic... The fan felt like it would break completely if I dropped it❗
Ergonomics: This design is extremely UNERGONOMIC😕. The hand positioning is so awkward and looks weird.
THE SOLUTION
Let me show you guys the sketches first so it's easier to understand❗
First is the sketch of the gear mechanism❗
Second is what my fan looks like❗ (I really tried on this ok)
(using the fusion skills that I learnt the last sem)
Q: "How do your improvements address the problems❓
A: Let me go through them one by one❗
The first thing I wanted to do was fix was the crank. To do this, I added a return springs and changed the method by which the crank turns the gears. Let me try to explain how it works using words. When you press down🔽 on the crank arm, the teeth on the rectangle thingy will mesh with the teeth of the gears⚙ causing it to turn. After the arm is pressed down once, the arm will automatically return back to its starting position as there is a spring that would be stretched and at high tension when it's pressed down, so when you release the tension on the arm, it will go back and you can re-squeeze the arm to turn the fan even faster and for longer❗❗
The second thing I fixed was the exterior design. (Not gonna lie, the original was so meh to look at 😕). This was just a simple fix as I just changed the shape from something flat to something more rounded, similar to the shape of a capsule 💊 as it has a more natural grip. (Even more natural if you're a LEGO 🧱).
I'm going to combine the third and fourth problems together. The original design was made of plastic and felt so cheap, brittle, AND NOT SUSTAINABLE 😤 (I was so scared that I was going to break it 😬). Not only that, as mentioned above, the fan is really unergonomic and can cause hand cramps if you keep pushing the lever in that awkward position 🤦♂️.
So how did I fix it❓
First of all, I changed the base of the body to metal❗ 🛠️ (Okay, I just wanna say I didn’t actually build this IRL, but if I did, I would make it metal 😅). What kind of metal❓ Honestly, anything that doesn’t rust and still has weight to it. (Weight = Premium, according to Apple’s Logic 🍎)
The next thing I did was add some finger pads and a trigger-looking thing (I forgot what it’s called, but just refer to the sketch, and you’ll know what I mean 🎨). I added this so you can keep squeezing the arm continuously without fear of your hand falling off❗🖐️ I also added extra padding so your hand has a more neutral and comfortable grip. ✨
You might be wondering why I didn’t talk about or change the gear train or ratio 🤔. In my opinion, I feel that the amount of force needed to spin the fan was just right and didn’t really need any tweaking to it.👌
Also, now that the handle is more ergonomic, I don’t think anyone would be complaining about the force needed as the arm goes back to its neutral position automatically 💪✨
Okay, wait, I need to explain something to you... ❗ By right, because the lever arm rotates the other way on the way back, the gears will spin in the opposite direction as well. This means the gear will stop spinning and slow down the fan😩
To fix this, there’s a need to make the big idler gear in my sketch "movable". For example, when pushing down on the lever, the idler gear gets pushed to the gears connected to the fan. To do this, you just need to make the hole the gear is screwed onto change from a circle to something like a rectangle with rounded edges. 🛠️
I would show it in my sketch, but it’s really hard because of my drawing skills 😔. (I shall work on my drawing skills ✍️).
ANYWAYS... That's how I would improve on the Hand-Squeezed Fan❗
Chapter 1.4: Gear Train!
experiment time!
ACTIVITY TIME✨
One of the tasks that we had to do was raise an empty water bottle using a series of gears, also known as a gear train ❗ This was one of the more unique practicals that I had to do in both ICPD and CPDD. (The module coordinator is cooking fr 🤯).
But of course, Ms Tan made it fun for us to learn as well ❗😊
Before the practical itself, my dearest groupmate, ✨Muhsin✨, did some preparation by trying to think of the highest possible gear ratio. He ended up with 26.67 and... IT WAS RIGHT ❗👏 Okay, I can't give him all the credit because the rest of us also tried our very own gear sequences. Turns out that there were so many different ways to get a gear ratio of 26.67 ❗ This really showed me how there’s more than one solution to everything, and sometimes, you just have to think a little extra 🤔.
Okay, remember when I said we were right❓ I mean, we didn’t know we were right immediately because we had a specific TE (no name calling, but the last name rhymes with Achoo! 🤧) who said we didn’t have the highest❓(Praying on our downfall fr 😤). Anyway, we ended up using Muhsin’s gear train instead of the rest, as we wanted to show appreciation for his effort and initiative❗💪
(Muhsin, if you're reading this, hello 👋)
Below are the calculations for the gear ratio as well as the sequence of gears that we used❗
Want to see how it looks like IRL❓ SURE❗❗
You might be wondering why we wanted a gear ratio as high as possible ❓ That’s because the main purpose of the gear train is to lift the bottle up using minimum force ❗ This means that we let the gears do the work for us by having a torque multiplier as ✨high✨ as possible. Initially, I thought that this section was a bit unnecessary🥱, as we could just pick it up ourselves, right? 🤔
NO❗
This section is more about showing how industries use gears to make lifting heavy things easier ❗ Think about it❗ Workers can’t be expected to carry heavy cement blocks all day to build our houses, right❓🏠 That’s why we developed machines to do the heavy lifting for us❗💪
The next thing that we had to do was find the theoretical number of revolutions needed to raise the bottle up by 200mm.
Do you notice anything off about the calculations ❓ The assumption we are using is that there is no change in the diameter of the winch. Hence, our actual number of rotations is 50, as when the diameter increases, more distance is covered by each rotation🤯 For some reason, this was oddly interesting to me, as in Chemical Engineering, we make so many assumptions❗❗ Now I wonder what would happen if I make those same assumptions when I go for my internship because there might be a huge difference in what I’m trying to calculate... (hmmm 🤔)
Here's the video of the activity❗
This process was so painstakingly slow😭😭 but that's the same reason why we only needed 50 revolutions instead of something more❗ (remember what I said about gear ratios regarding speed and torque multipliers❓)
Chapter 1.5: Thoughts
POS RJ but more fun!
This is the part of my blog where I strive to articulate my thoughts and feelings with as much clarity and reflection as possible. I find this part honestly meaningful, as it allows me to take a step back and truly like, look back with what I’ve learned and experienced.
One of the most significant realisations I’ve had recently is how learning outside the boundaries of chemical engineering has broadened my perspective on engineering as a whole. Every field within engineering brings its own tools and methods to solve problems. For example, mechanical engineers rely on mechanisms like gears and other mechanical things, while computer engineers use coding to design and program those complex solutions. This realisation has been both humbling and as I said, eye-opening, as it shows the interconnectedness of engineering disciplines. It also led me to realise that there is no such thing as a purely "chemical engineering" industry. Most industries demand a blend of skills, knowledge, and collaboration across various branches of engineering. I think this insight is particularly relevant as I prepare for my internship, where I initially sought opportunities with job scopes that were solely aligned with chemical engineering. However, now I see the value in a more open-minded approach.
Reflecting on gears specifically, I’ve come to appreciate just how much there is to learn. While our practical sessions provided a great introduction, they only scratched the surface. I can tell because we haven’t delved deeply into applying complex principles like the moments equation (T = Fd) or other advanced calculations that might come into play. This surface-level exposure has motivated me to dig deeper through self-directed research. Why would I want to research more? This deeper understanding could be valuable for my Final Year Project (FYP) or even my upcoming CPDD project related to a Gas Detector.
What stood out to me the most, however, was gaining a new appreciation for the purpose and versatility of gears. Yes, gears are all around us; in clocks, bicycles, and more! But their true importance lies in their ability to do what we can't. For example, lifting a heavy cement block is beyond our physical capacity for prolonged periods, but gears make it possible by distributing and multiplying force or torque. Similarly, consider a task like kneading dough, it’s tedious and exhausting when done manually, but with the help of gears, which can act as speed multipliers, the burden on us is significantly reduced. Gears amplify our capabilities, allowing us to achieve more with less effort.
This understanding of gears as tools that extend human potential resonates deeply with me (Big words) It’s a reminder of why engineering exists in the first place! To innovate, solve problems, and make life better and easier for all of us. It also reinforces my belief that every bit of knowledge, no matter how unrelated it seems to my core field, can eventually prove useful. This insight has given me a renewed sense of curiosity and a desire to explore topics beyond what’s immediately required.
In conclusion, this experience has been a powerful reminder that there’s always more to learn, and every lesson. no matter how simple it seems, does have a purpose. I look forward to taking this curiosity into my internship and beyond, as I continue to uncover the endless possibilities within engineering❗
Overall, I would say I have not had this much fun in a long time and it's nice to try new things out!
That's it for this blog! BYEBYE👋
Comments