Tiếng Anh Cơ khí 1 by 26-Hoàng Đinh

Unit 1: Writing

nekomen06 — 2022-09-19 12:57:33 UTC

Hello everyone, today I'm going to talk about how to make an effective presentation. First of all, the basic structure of a presentation consists of three parts: the introduction, the body, and the conclusion. Each parts has a different function and they are very important to make a good presentation. After that, before the presentation, you should choose a presentation style and create the slide: make the font, color and some picture illustrate. You can stand in front of the mirror and practice facial expession,… or you can speak in front of others and get feedback. Besides , in the presentation, you should make eye contact, look at the audience and don’t look at the floor or celling. You should not look at the paper and read too much, but memorize the content. The last, you have to thank the audience after they ask some a question. If you don't know the answer to the question, you should admit that and promise to provide the answer later.

Unit 2: Writing 1

nekomen06 — 2022-09-29 13:14:10 UTC

Roller contact bearing uses rollers to support the load. They have an inner and outer race. Average load capacity is low. There are two main types: Contact Roller Bearings and Jounal Bearings. Main contact roller bearings include 4 types: ball bearings, straight roller bearings, tapered roller bearings and thrust roller bearings
Ball bearings use spherical rollers. They support radial and axial movement
Straight roller bearings use cylindrical roller bearings. They support radial movement
taper using conical roller. They support moderate radial and repulsive forces
Thrust roller bearings use barrel-shaped rollers. They support propulsion motion
Jounal: Jounal bearings have no rolling elements. Their shaft rotates inside an alternate lubricated sleeve High load capacity

Unit 2: Writing 2

nekomen06 — 2022-09-29 13:14:40 UTC

There are two primary types of couplings: Rigid couplings and Flexible couplings
Rigid couplings align the shafts with each other. Perfect alignment reduces wear on the machin. Rigid couplings maximize performance and efficiency. Sleeve-style couplings are the most rigid coupling.

Flexible couplings transmit power without perfect alignment. Beam couplings are cut in a spiral shape. These can accommodate several degree of sahft offset. Flexible of couplings help reduce noise and unwantes vibrations
Couplings transmit power from one shaft to another . The input shaft connects to the power source. The output shaft connects to the destination.

Unit 3: Writing 1

nekomen06 — 2022-10-09 15:40:26 UTC

There are two types of drives include belt drive and chain drive. The belt drive is used to transmit motion and power form one shaft to another by means of friction between the belt and pulleys and the chain drive can transmit motion and power between successive chains with sprocket special toothed wheels. The belt drive is made of rubber, plastic urethane, or other substances and the chain drive is made of metal with a number of links. The belt can reduce noise and vibration and the chain drive can cause noise and vibration. The belt drive is comparatively low due to frictional loss and the chain drive is high (usually above 95%). The belt drive is minimum maintenance and frequent tension. The chain drive is regular maintenance (including frequent lubrication). The application of belt drives is flour mills and coolant pumps. Lubricant pump, AC, CAM shaft, alternator, lathe machines, and lots of other machines and belt conveyors. The application of the chain drive is bicycles, motorcycles, agricultural and textile machinery, and material handling equipment.

Unit 3: Writing 2

nekomen06 — 2022-10-09 15:56:13 UTC

Gear is a rotating circular component of the machine with teeth, which mesh with another toothed part to transmit torque. Geared devices can change the speed, torque, and direction of a power source. There are five types of gear include: spur gear, helical gear, worm and worm gears, rack and pinion gear, and bevel gear. The first, Spur gears have teeth projecting towards or away form the centre. It is used in low-speed applications and cannot control noise at high speed. The second, the helical gears have their teeth cut in a spiral shape. It is used in high-speed applications, has large power transmission, runs more smoothly and quietly, and controls noise. Next, the worm has just one continuous tooth and a worm paired with a worm gear can reduce speed. The rack and pinion gears are consists of a circular gear (the pinion) engaging a linear ( the rack). They are used to convert rotational motion into linear motion. The last, bevel gears have a conical form. The function of the bevel gears is to transmit rotational power through shafts at an angle, normally 90 degrees

Unit 2: Speaking1

nekomen06 — 2022-10-11 08:28:50 UTC

Unit 2: Speaking 2

nekomen06 — 2022-10-11 08:29:27 UTC

Unit 3: Speking 1

nekomen06 — 2022-10-11 08:31:04 UTC

Unit 3: Speaking 2

nekomen06 — 2022-10-11 08:31:57 UTC

Unit 4: Writing 1

nekomen06 — 2022-11-04 09:02:37 UTC

Manual drafting is simply known as the practice of creating drawings by hand, you use pens, rulers and erasers to create the drawing. In general, CAD can solve all of the difficulties you meet when draft manually and helps you produce very accurate designs, the error is very small. Your drawings can be created in 2D or 3D. It has the ability to create exploded views of machinery parts. However, CAD has some disadvantages too. You have to have a computer to use a CAD program. Nowadays lots of people have the ability to access to computer but in some remote areas few engineers don't. Moreover, with some people a CAD program is not easy to use, it will take them few days or months to get used to using it.

Unit 4: Writing 2

nekomen06 — 2022-11-04 09:03:02 UTC

Nx first time released in 1973, it is a simple, useful and powerful software. It's used in aerospace and automotive companies. The functions of Nx including creating drawings, 2D or 3D models, editing data and collecting multiple design elements into a single feature. It's fast and flexible, it helps reduce mistakes and maximize the productivity. It can also track your product through every phase of the production cycle easily. However, before you can use Nx, you have to be trained professionally. Nx is also can not be able to handle super complex parts or assemblies. So overall, Nx is a very useful program for drawing, make it more easily for companies and factories to design.

Unit 5: Writing

nekomen06 — 2022-11-04 09:03:39 UTC

The check valve is made of cast iron.
First step is casting, hot iron is poured into a container and cooled to make the correct shape.
The cast iron is then turned on a lathe machine.
Next, the check valve is drilled to make holes.
After drilling process, the next step is painting, the surface of the check valve is covered by paint.
Next is bolting process, pieces of it are joined together using nuts and bolts
The final step is inspection.
This is when we make sure that the part is made properly.

Unit 6: Writing 1

nekomen06 — 2022-11-04 09:04:02 UTC

As far as I know, plastic is a synthetic material that use polymers as a main ingredient. Plastic is able to be molded or shaped to any forms. The properties of plastic are versatile, lightweight, durable and some kind of plastic are saft . Plastic brings us a great number of benefit. The firstly, the plastic is versatile help them be shaped easily in to a wide range of forms. The secondly, it is lightweight, which is used in manufacturing airplane interiors and exterior parts. The next, plastic is cost-efficient because it formed into final useful form quickly and inexpensively. first of all, Most plastics are non-degradable and they may take a long time to break down once they are landfilled. Moreover, most of plastic product is not recycled and disposed of directly into the environment, which is hurt the enviroment. now, Human lifestyle and plastic inseparable. Nowaday, plastic are made from oil, coal and natural gas but in the near future, we will be able to make plastic form any kind of plant material. In short, plastic is a useful material for life and production, but besides that, there are still many plastic problems that we need to solve.

Unit 4: Speaking 1

nekomen06 — 2022-11-10 14:05:50 UTC

Unit 4: Speaking 2

nekomen06 — 2022-11-10 14:06:33 UTC

Unit 6: Speaking 1

nekomen06 — 2022-11-10 14:25:32 UTC

Unit 7: Writing 1

nekomen06 — 2022-11-14 15:49:50 UTC

The most common process of plastic moulding is the injection moulding process. The injection molding products are accurate in size, easy to be replaced, and can be formed into complex shapes. There are 5 steps to in the moulding process. The first step is feeding. In this step, the pellets of plastic are fed from the hopper in to a cylinder. In the second step is plasticization, pellets are pushed along the cylinder by a rotation screw, and heated to creat moulten plastic. Then the screw stops rotating and a ram in fornt of the screw moves straight forward. The next step is the injection, the soft and warm platic are pushed toward a nozzle by the ram. They are injected through the nozzle into a shape cavity in the mould. After the plastic is filled the cavity, the plastic is transferred the cooling step. In this step, the plastic is cooled in the mould and becomes hard, strong. The final step is ejection, the mould opens and plastic shape is ejected. Those are the basic steps in the injection moulding process.

Unit 7: Writing 2

nekomen06 — 2022-11-14 15:50:28 UTC

From my point of view, there are 3 typical problem of plastic injection moulding. They are short shot, sink mark and void. As I know, short shot is cause of 2 reasons. Firstly, there is not enough plastic in the shot. Secondly, the plastic pressure loss in the mould is too high. We have 2 ways to avoid these causes. The first one is increasing fill speed, plastic and moud temperature. Next, we could increase gate size and runner. The void is created by shrinkage. It is volume change of plastic when plastic is heated or cooled. To attack this problem, we have 3 ways. The firt way is reducing wall thickness. Then, you should slow down cooling rate. Beside, we can increase gae size and locate it at the thick oart of the moulding. The final problem is sink mark. There are some reasons of this phenomena as the internal stress is too high and the part has low surface rigidity. The ways to solve is pretty simple. We need to have enough shot size and increase holding pressure, holding time. Beside that, we should reduce mould temperature and wall thichness for faster. Those are some typical problems of plastic injection moulding and the ways to attack them.

Unit 1: Speaking

nekomen06 — 2023-09-22 15:16:01 UTC

Unit 5: Speaking 1

nekomen06 — 2023-10-20 19:01:50 UTC

Unit 5: Speaking 2

nekomen06 — 2023-10-20 19:02:05 UTC

Unit 6: writing 2

nekomen06 — 2023-10-27 18:06:41 UTC

As I know, there are 7 types of plastic with different uses and features including: PET, HDPE, PVC, LDPE, PP, PS and other Plastic. The frist one is PET. Its code is number 1. It is strong and recyclable. We use PET to make food and drink packaging. The sencond one is HIDE. It is hard, resistant to impact, subjected to high temperatures and recyclable. We use HIDE to make grocery bags, milk jugs, recycling bins, agricutural pipes, playground equipment, lids, and shampoo bottles. Thirdly, the properties of PVC/V are lightness, durability, and easiness. PVC/V is divided into 2 form: rigid and flexible form. In its rigid from, PVC/V is largely used in the building and construction industry to produce door and window profiles and pipes. In flexible form, it can be made flexible and applied to plumbing, wiring and electrical cable insulation and flooring. Finallly, PP is hard, sturdy, resistant to fatigue. We use PP to make plastic bags, six-pack rings, various containers, dispensing bottles, plastic wraps

Unit 6: Speaking 2

nekomen06 — 2023-10-31 17:45:22 UTC

Unit 7:Speaking 1

nekomen06 — 2023-11-08 01:36:15 UTC

Unit 7: Speaking 2

nekomen06 — 2023-11-08 01:36:59 UTC

Unit 8: Writing 1

nekomen06 — 2023-11-15 01:47:04 UTC

Introducing the "PrecisionTurn 2000," a versatile lathe that stands as a cornerstone of precision engineering. This machine tool excels in turning, threading, and intricate machining tasks. To ensure its consistent performance, a well-structured maintenance schedule has been devised. Daily tasks involve checking water line pressure gauges and air pressure levels, along with a warm-up routine for the spindle at low speed for five minutes. The chip filter is also meticulously cleaned. On a weekly basis, these efforts are reinforced, ensuring the machine's vital components remain in optimal condition. Such proactive maintenance preserves accuracy, minimizes wear and tear, and reduces the risk of unplanned downtime. By adhering to this routine, the PrecisionTurn 2000 delivers reliable and efficient operations, consistently producing high-quality components and bolstering overall productivity.

Unit 8: Writing 2

nekomen06 — 2023-11-15 01:47:45 UTC

Introducing our state-of-the-art machine tool series, the "PrecisionMachina Line." With its prowess in precision milling, drilling, and intricate shaping, these tools play a pivotal role in modern manufacturing. A meticulously crafted maintenance schedule ensures seamless operations and prolonged equipment life. Daily tasks encompass fluid level checks, air pressure assessments, and spindle warm-ups, complemented by regular chip filter cleaning. Weekly maintenance reinforces these actions, maintaining optimal conditions for crucial components. On a monthly basis, thorough inspections of spindle alignment, tool magazines, and coolant systems are conducted to uphold precision. Quarterly assessments of electrical systems and software updates are also paramount. These maintenance activities proactively prevent deterioration, reduce unplanned downtime, and uphold consistent precision, thus elevating the quality of manufactured products while maximizing production efficiency.

Unit 8: Speaking

nekomen06 — 2023-11-21 10:13:55 UTC