BELT DRIVE 1. A belt is a looped strip of flexible material, used to mechanically link two or more rotating shafts. 2. They may be used as: 1. a source of motion, 2. to efficiently transmit power, 3. or to track relative movement. Belts are looped over pulleys. 1. In a two pulley system,
1. the belt can either drive the pulleys in the same direction, 2. or the belt may be crossed, so that the direction of the shafts is opposite. Open versus cross belt drives OPEN BELT DRIVE
Belts on a Yanmar 2GM20 marine diesel engine Open belt drive Typical problem = calculate the length of the belt drive for given wheels system PROBLEM
Following are the details of a crossed belt drive. Calculate the length of the belt? Diameter of the driver : 200 mm Diameter of the follower : 400 mm
Center distance of the drive : 2m Speed of the driver : 400 rpm Angle of contact : 197.3 Determine the length of the belt.
Solution: D1 = 200 mm D2= 400 mm C = 2m N1 = 400 rpm Length of the belt = L =2C+ / 2 (D1+ D2) + (D1+ D2) / 4CD1+ D2) + (D1+ D2) + (D1+ D2) / 4CD1+ D2) / 4C = (D1+ D2) + (D1+ D2) / 4C2x2) + / 2 (D1+ D2) + (D1+ D2) / 4C0.2+ 0.4) + (D1+ D2) + (D1+ D2) / 4C0.2+ 0.4) / 4x2 = 4.99 m
CROSS BELT DRIVE Cross belt drive. TYPES OF BELT DRIVES FLAT BELT
VEE BELT TIMING BELT ROUND BELT WHEN SHOULD WE
USE BELT DRIVES? Advantages of belt drive 1. 2. 3. 4. 5.
6. 7. They are simple. They are economical. Parallel shafts are not required. Overload and jam protection are provided. Noise and vibration are damped out. Machinery life is prolonged because load fluctuations are cushioned (D1+ D2) + (D1+ D2) / 4Cshock-absorbed).
They are lubrication-free. They require only low maintenance. They are highly efficient (D1+ D2) + (D1+ D2) / 4C9098%, usually 95%). Some misalignment is tolerable. They are very economical when shafts are separated by large distances. Disadvantages of belt drive 1. The angular-velocity ratio is not necessarily constant or
equal to the ratio of pulley diameters, because of belt slip and stretch. 2. Heat buildup occurs. Speed is limited to usually 7000 feet per minute (D1+ D2) + (D1+ D2) / 4C35 meters per second). Power transmission is limited to 370 kilowatts (D1+ D2) + (D1+ D2) / 4C500 horsepower). 3. 4. Operating temperatures are usually restricted to 31 to 185F (D1+ D2) + (D1+ D2) / 4C35 to 85C). 5. Some adjustment of center distance or use of an idler pulley
is necessary for wear and stretch compensation. 6. A means of disassembly must be provided to install endless belts. CHAIN DRIVES CHAIN Roller chainDRIVES
and sprocket Chain drive 1. Chain drive is a way of transmitting mechanical power from one place to another. 2. It is often used to convey power to the wheels of a vehicle, particularly bicycles and motorcycles. 3. It is also used in a wide variety of machines besides vehicles.
4. Most often, the power is conveyed by a roller chain, known as the drive chain, passing over a sprocket gear, with the teeth of the gear meshing with the holes in the links of the chain. 5. The gear is turned, and this pulls the chain putting mechanical force into the system.. system Possible Questions
Short Answer Questions 1. 2. 3. 4. 5. Differentiate between open belt and crossed belt drive. What are the commonly used materials for flat belts?
List out the applications of belt drives. What do you mean by slip in a belt drive? Differentiate between belt drive and chain drive. Long Answer Questions 1. 2. 3. 4.
Explain with neat sketch, the types of various flat belt drives. List out the advantages and disadvantages of belt drives. Compare flat belt and V belts. Briefly explain chain drives.
In his darkroom he is finally alone with spools of suffering set out in ordered rows. The only light is red and softly glows, as though this were a church and he a priest preparing to intone a Mass. Belfast.
Homework Draw the Bohr model, Lewis dot diagram and Electron configurations for the following elements: potassium, aluminum, silicon, helium, beryllium. Engage Students will brainstorm on scratch paper/Post-it notes what they think chemists do to identify elements in a sample.
Organizational feasibility. Training and indoctrination . Change control and technology governance. Project Planning Considerations (cont'd.) Financial considerations. No matter what information security needs exist, the amount of effort that can be expended depends on funds available.
Write the ordered pairs that name points A, B, C, and D. The x-axis and y-axis separate the coordinate plane into four regions, called quadrants. Name the quadrant in which each point is located (-5, 4) Name the quadrant in...
Outlook Express Maarja Kask Produced at: Tartu Kutsehariduskeskus Outlook Express Maarja Kask ACTION PROGRAMME OF THE EUROPEAN UNION LEONARDO DA VINCI PROJEKT NO.: 2002 LA 112 628 BILVOC Language Competence Through Bilingual Teaching at Vocational Colleges * *
Panamic Fanged Blenny, Ophioblenniussteindachneri: [Adults] are common and always found in tidal pools, even with extreme low tides, with plenty of water and a place to hide under a rock. . . Collected in January 2008 in a dry El...
Three GE Projects at SJSU Compass Project Stephen Branz & Maureen Scharberg (Debra David) GE Program Assessment ... Increased participation in high-impact practices (e.g., service-learning, learning communities, internships, study abroad) Compass Project Project Components "Transfer-year ...
Ready to download the document? Go ahead and hit continue!