1. Purpose Of The Tangential Slots In An Oil Burner Nozzle
2. Purpose Of Tangential Slots Definition
3. Purpose Of Tangential Slots Games

Tangential jet slots were incorporated for bi-directional force generation. Findings include: finite-span effects on CC augmented lift are consistent with the effects on conventional lift-due-to-angle-of-attack, and cavitation in the Coanda wall jet region does not result. The slot end to end (tangent) length is a function of the slot clearance, and for that clearance we can pick tight, normal or lose and not bother with what actual value it is - except that value affects the important range of movement for the fastener. We change the fit of the slot and it changes the range of movement for the fastener! A tangential vortex intake is a compact structure that can convey storm water efficiently as a swirling flow down a vortex dropshaft. It has been studied in physical models and successfully employed in urban drainage and hydroelectric plant applications, but a comprehensive account of the key flow characteristics has not been reported and a theoretical design guideline of a tangential intake is.

The main purpose of this study is to present a new and very simple empirical. The flow changes its direction again in the tangential direction along the tip seal slot indicated in region “C” (labelled ③), as shown in Figure 1(c). The out flow (labelled ③ to ⑤) from the tip seal slot into the low pressure region is. Pin slot, with an arrow in the direction of the slot. More tips for visualizing Mates: Select a part, right-click for the context menu and select Show mates. Hover over a Mate, right-click for the context menu where you are able to take action on the Mate.

In mechanical engineering, a key is a machine element used to connect a rotating machine element to a shaft. The key prevents relative rotation between the two parts and may enable torque transmission. For a key to function, the shaft and rotating machine element must have a keyway and a keyseat, which is a slot and pocket in which the key fits. The whole system is called a keyed joint.[1][2] A keyed joint may allow relative axial movement between the parts.

Commonly keyed components include gears, pulleys, couplings, and washer

Types[edit]

There are five main types of keys: sunk, saddle, tangent, round, and spline.

Sunk key[edit]

Types of sunk keys: rectangular, square, parallel sunk, gib-head, feather, and Woodruff.

Parallel keys[edit]

Parallel keys are the most widely used. They have a square or rectangular cross-section. Square keys are used for smaller shafts and rectangular faced keys are used for shaft diameters over 6.5 in (170 mm) or when the wall thickness of the mating hub is an issue. Set screws often accompany parallel keys to lock the mating parts into place.^[1] The keyway is a longitudinal slot in both the shaft and mating part.

• The keyseat in a shaft for a parallel key

• A sprocket with an internal parallel keyway

• Cross-section of a parallel keyed joint

W = d/4^{[clarification needed]}

H = 2d/3^{[clarification needed]}

where

• W is the key width
• H is the key height
• d is the shaft diameter

Woodruff keys [edit]

Woodruff keys are semicircular, fitting partly into A*B circular segment keyway with the remainder fitting into a longitudinal slot keyway in the mating part. The circular segment can be cut directly by plunge cutting with a circular Woodruff cutter without any reliefs. The main advantage of the Woodruff key is the elimination of milling near shaft shoulders, where stress concentrations,^[2] and concentricity would be affected.^[1] The latter is particularly important for high speed operation. The more exact fit of the key and keyway also reduces play, and stress concentrations in, and improves the reliability of the key. An additional advantage is a stuck key can be removed from a shaft with a hammer blow, the circular profile will push the key out of the slot, as opposed to a standard key which will need to be pushed axially, or pulled out of its slot. Common applications include machine tools, automotive applications, snowblowers and marinepropellers.

This type of key was developed by W.N. Woodruff of Connecticut. In 1888, he was awarded the John Scott Medal by the Franklin Institute for his invention.^[3]

• A Woodruff key installed

• A Woodruff key and keyway

• Gear G is positively located on shaft S by Woodruff key N

Tapered keys[edit]

The tapered key is tapered only on the side that engages the hub. The keyway in the hub has a taper that matches that of the tapered key. Some taper keys have a gib, or tab, for easy removal during disassembly. The purpose of the taper is to secure the key itself, as well as, to firmly engage the shaft to the hub without the need for a set screw. The problem with taper keys is that they can cause the center of the shaft rotation to be slightly off of the mating part.^[1] It is different from a tapered shaft lock in that tapered keys have a matching taper on the keyway, while tapered shaft locks do not.

Others[edit]

A Scotch key or Dutch key features a circular keyway hole (instead of rectangular), produced by drilling axially into the assembled hub and shaft, with a metal dowel pin serving as the key. If the hole and key are tapered, the key is referred to as a Dutch pin, which is driven in and optionally finished by cutting or grinding flush with the end of the shaft. If a straight Dutch keyway hole is optionally tapped with a thread, then an ordinary screw serves as the threaded Dutch key.

Spring pins are an alternative Dutch key component, instead of solid dowel pins. A spring pin is self-fastening and does not work loose under vibration. Hollow spring pins provide a weaker shear strength than a solid dowel pin, and the strength may be varied by varying the wall thickness. This limited shear strength specification is designed to sustain normal operation, but then give way in the event of excessive shaft torque, thus protecting the rest of the machine from damage.

Introducing an additional bushing component between hub and shaft improves the performance and convenience of keyed joints. Taper-Lock bushings are keyed hub fittings which provide three threaded Dutch keyways and two setscrews as Dutch keys, in addition to the rectangular keyway. The Dutch keyways are threaded only on the alternate hub side or shaft side, with a thread clearance hole form on the opposite side. By simply driving setscrews into selected holes, the hub mechanism conveniently operates to rigidly lock or definitely release from the shaft, without hammering or hub-pulling. Quick-disconnect (QD) bushings work similarly, but place a circular pattern of three unthreaded and three fully threaded holes further out from the shaft axis on a bushing flange, instead of across the bushing-to-hub interface.

A Hirth joint is similar to a spline joint but with the teeth on the end of the shaft instead of on the surface.

Saddle keys[edit]

These types of keys are generally attached to the driving member (e.g. shafts). These types of keys have less strength as compared with the sunk keys. These are rarely used keys, to transmit lower power to the driven members (e.g. couplings)

Tangent keys[edit]

Tangent keys are used in high-torque heavy-duty applications. The keyway is similar to a parallel key, except it extends tangentially out of the external shaft into the internal shaft. What would have been the side of each keyway forms heels against which the key sits, and transfers force compressively. This latter point means that for reversible motion of the shaft, another key along a tangent outwards in the opposing direction is needed. Typically this will be offset by 90° or 180° on the shaft. The key may be wedge, rectangular, or square shaped, but particularly rectangular double-taper keys are used.

Spline key[edit]

This type of key uses multiple keyways in the hub to transmit high power.

Keyseating[edit]

Keyseating is the creation of the slots in the mating items. Keyseating can be done on a variety of different machines including a broach, a keyseater, wire-cut EDM, a shaper or vertical slotting machine, either a vertical or horizontal mill, or with a chisel and file.

• Keyway cutters

• Special cutters

• Slotting tools

• Different slotting tools

Broaching[edit]

Broaching is primarily used to cut square cornered internal keyways. The specific broach, bushing and guide are used for each given keyway cross-section, which makes this process more expensive than most of the alternatives. However, it can produce the most accurate keyway out of all the processes. There are three main steps in broaching a keyway: First, the workpiece is set on the arbor press and the bushing is placed in the opening of the workpiece. Next, the broach is inserted and pushed through, cutting the keyway. Finally, shims are placed between the bushing and the broach to achieve the correct depth necessary for the key.^[4]

Keyseater[edit]

Keyseaters, also known as keyseating machines and keyway cutters, are specialized machines designed to cut keyways. They are very similar to vertical shapers; the difference is that the cutting tool on a keyseater enters the workpiece from the bottom and cuts on the down-stroke, while the tool on a shaper enters the workpiece from the top and cuts downward. Another difference is a keyseater has a guiding system above the workpiece to minimize deflection, which results in a closer tolerance cut. The process starts by clamping the workpiece to the table with a fixture or vise. The workpiece is properly located and then the reciprocating arm is started. Some models have a stationary table so the cutter is fed horizontally into the workpiece, while others have a movable table that feeds the workpiece into a fixed cutter. These machines can cut other straight sided features other than keyways (see the picture). They can also produce blind slots, which are slots that do not extend through the whole workpiece.^[5][6]

Wire-cut electrical-discharge machining (EDM)[edit]

Wire-cut electrical-discharge machining (EDM) is primarily used for small production lot sizes where either extreme precision is required or other cutting technologies are not readily available. Wire-cut EDM cuts keyways by eroding material away from the workpiece through a series of rapid electric current discharges between a spooling wire and the workpiece through a dielectric liquid. Computer numerical control (CNC) wire-cut EDM machines allow for a wide variety selection of keyways to be cut, inclusive of multiple keyways on the same hub. The main limitations of CNC wire-cut EDM is the time it takes to cut a keyway as well as the size of parts a given wire-cut EDM machine can accommodate.^[7]

Shaping or slotting[edit]

Shaping or slotting is largely used for cutting keyways that do not extend through the full length of the part. Like keyseating, shaping uses a single-point cutting tool for cutting, however, shapers are not guided through the cut on a fixed post. As such, shaper cuts are generally more susceptible to deflection than keyseater cuts.^[7]

Milling[edit]

Parallel, tapered, and Woodruff keyways can be produced on a milling machine. End mills or slotting cutters are used for parallel and tapered keyways, while a Woodruff cutter is used for Woodruff keyways.^[8]

For internal keyways that are not too long, the keyways can be milled if a radius is acceptable.

Chiseling[edit]

One of the earliest forms of keyseating was done by chiseling. The keyway is roughed out using a chisel and then filed to size; the key is tried frequently to avoid over filing. This technique is long, tedious, and rarely used anymore.^[9]

Keyed joints[edit]

A shear key is a feature intended to fail and avoid further damage should the machinery be accidentally operated in excess of its design limits. Shear keys may be any of the designs described above, but are made from a weaker material than the shaft. The shear key is easily and inexpensively replaced, and avoids more serious damage to the mechanism that would be costly or difficult to repair. For example, a steel shaft and pulley may employ a brass key. When excessive torque is applied to the joint, the steel edges shear the brass key into two pieces, leaving the pulley spinning loosely on the shaft and relieving the rest of the machine from possible damage.

Two parallel keys can be used if the shaft connection requires a higher torque rating.^[1]

Improperly machined keyways that had cutter deflection or drifting occur, may not be strong enough for the required application.^[10]

See also[edit]

Purpose Of The Tangential Slots In An Oil Burner Nozzle

References[edit]

1. ^ ^abcdKeys and Keyways(PDF), archived from the original(PDF) on 2010-03-19, retrieved 2010-03-19.
2. ^Shigley, Joseph; Mischke, Charles (1989), Mechanical Engineering Design (5 ed.), McGraw-Hill, ISBN0-07-331657-1.
3. ^Garfield, Eugene (2007). 'The John Scott Award Recipients from 1826 - present'. Retrieved 2007-08-23.
4. ^Krar, S. F. (1983). Machine tool operations. (pp. 84–85). New York: Gregg Division McGraw-Hill.
5. ^Keyseating, retrieved 2010-01-30.
6. ^Wick, C. H. (1964). Versatility of keyseating. Machinery (NY), 70(8), 138-140.
7. ^ ^abCutting Keyways - Broaching, Keyseating, Wire-Cut EDM, Shaping, & Milling, retrieved 2014-12-03.
8. ^Kibbe, R. R. (1995). Machine tool practices. (5th ed. ed., p. 572). Englewood Cliffs, New Jersey: Prentice-Hall, Inc.
9. ^Leonard 1908, p. 40 harvnb error: no target: CITEREFLeonard1908 (help).
10. ^Romig, J. V. (1926). The Popular Science Monthly. The Popular Science Monthly., 110(5), 72, 124.

Bibliography[edit]

• Leonard, William Samuel (1919). Machine-shop Tools and Methods (Revised 7th ed.). New York: John Wiley & Sons. pp. 39–42. OCLC848146647. Retrieved 30 April 2019.

External links[edit]

• Key joint article from the 1979 Great Soviet Encyclopedia

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Sloth, (suborder Phyllophaga), tree-dwelling mammal noted for its slowness of movement. All five living species are limited to the lowland tropical forests of South and Central America, where they can be found high in the forest canopy sunning, resting, or feeding on leaves. Although two-toed sloths (family Megalonychidae) are capable of climbing and positioning themselves vertically, they spend almost all of their time hanging horizontally, using their large hooklike extremities to move along branches and vines. Three-toed sloths (family Bradypodidae) move in the same way but often sit in the forks of trees rather than hanging from branches.

What kind of animal is a sloth?

Sloths are mammals. They are part of the order Pilosa, which is also home to anteaters. Together with armadillos, sloths and anteaters form the magnorder Xenarthra.

How many types of sloths are there?

A total of five species of sloths exist: the pygmy three-toed sloth, the maned sloth, the pale-throated three-toed sloth, the brown-throated three-toed sloth, and Linnaeus's two-toed sloth. All sloths are either two-toed or three-toed.

Where do sloths live?

Sloths live in the lowland tropical areas of South and Central America. They spend most of their life in the forest canopy. Two-toed sloths tend to hang horizontally from branches, while three-toed sloths often sit in the forks of trees.

What do sloths eat?

Sloths are omnivores. Because they spend most of their time in trees, they like to munch on leaves, twigs, flowers, and other foliage, though some species may eat insects and other small animals.

Why are sloths so slow?

Sloths are slow because of their diet and metabolic rate. They eat a low-calorie diet consisting exclusively of plants, and they metabolize at a rate that is only 40–45 percent of what is expected for mammals of their weight. Sloths must move slowly to conserve energy.

Sloths have long legs, stumpy tails, and rounded heads with inconspicuous ears. Although they possess colour vision, sloths’ eyesight and hearing are not very acute; orientation is mainly by touch. The limbs are adapted for suspending the body rather than supporting it. As a result, sloths are completely helpless on the ground unless there is something to grasp. Even then, they are able only to drag themselves along with their claws. They are surprisingly good swimmers. Generally nocturnal, sloths are solitary and are aggressive toward others of the same sex.

Sloths have large multichambered stomachs and an ability to tolerate strong chemicals from the foliage they eat. The leafy food is digested slowly; a fermenting meal may take up to a week to process. The stomach is constantly filled, its contents making up about 30 percent of the sloth’s weight. Sloths descend to the ground at approximately six-day intervals to urinate and defecate (see Sidebar: A moving habitat). Physiologically, sloths are heterothermic—that is, they have imperfect control over their body temperature. Normally ranging between 25 and 35 °C (77 and 95 °F), body temperature may drop to as low as 20 °C (68 °F). At this temperature the animals become torpid. Although heterothermicity makes sloths very sensitive to temperature change, they have thick skin and are able to withstand severe injuries.

All sloths were formerly classified in the same family (Bradypodidae), but two-toed sloths have been found to be so different from three-toed sloths that they are now classified in a separate family (Megalonychidae).

Three-toed sloths

The three-toed sloth (family Bradypodidae) is also called the ai in Latin America because of the high-pitched cry it produces when agitated. All four species belong to the same genus, Bradypus, and the coloration of their short facial hair bestows them with a perpetually smiling expression. The brown-throated three-toed sloth (B. variegatus) occurs in Central and South America from Honduras to northern Argentina; the pale-throated three-toed sloth (B. tridactylus) is found in northern South America; the maned sloth (B. torquatus) is restricted to the small Atlantic forest of southeastern Brazil; and the pygmy three-toed sloth (B. pygmaeus) inhabits the Isla Escudo de Veraguas, a small Caribbean island off the northwestern coast of Panama.

Although most mammals have seven neck vertebrae, three-toed sloths have eight or nine, which permits them to turn their heads through a 270° arc. The teeth are simple pegs, and the upper front pair are smaller than the others; incisor and true canine teeth are lacking. Adults weigh only about 4 kg (8.8 pounds), and the young weigh less than 1 kg (2.2 pounds), possibly as little as 150–250 grams (about 5–9 ounces) at birth. (The birth weight of B. torquatus, for example, is only 300 grams [about 11 ounces].) The head and body length of three-toed sloths averages 58 cm (23 inches), and the tail is short, round, and movable. The forelimbs are 50 percent longer than the hind limbs; all four feet have three long, curved sharp claws. Sloths’ coloration makes them difficult to spot, even though they are very common in some areas. The outer layer of shaggy long hair is pale brown to gray and covers a short, dense coat of black-and-white underfur. The outer hairs have many cracks, perhaps caused by the algae living there. The algae give the animals a greenish tinge, especially during the rainy season. Sexes look alike in the maned sloth, but in the other species males have a large patch (speculum) in the middle of the back that lacks overhair, thus revealing the black dorsal stripe and bordering white underfur, which is sometimes stained yellow to orange. The maned sloth gets its name from the long black hair on the back of its head and neck.

Three-toed sloths, although mainly nocturnal, may be active day or night but spend only about 10 percent of their time moving at all. They sleep either perched in the fork of a tree or hanging from a branch, with all four feet bunched together and the head tucked in on the chest. In this posture the sloth resembles a clump of dead leaves, so inconspicuous that it was once thought these animals ate only the leaves of cecropia trees because in other trees it went undetected. Research has since shown that they eat the foliage of a wide variety of other trees and vines. Locating food by touch and smell, the sloth feeds by hooking a branch with its claws and pulling it to its mouth. Sloths’ slow movements and mainly nocturnal habits generally do not attract the attention of predators such as jaguars and harpy eagles. Normally, three-toed sloths are silent and docile, but if disturbed they can strike out furiously with the sharp foreclaws.

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Reproduction is seasonal in the brown- and pale-throated species; the maned sloth may breed throughout the year. Reproduction in pygmy three-toed sloths, however, has not yet been observed. A single young is born after less than six months’ gestation. Newborn sloths cling to the mother’s abdomen and remain with the mother until at least five months of age. Three-toed sloths are so difficult to maintain in captivity that little is known about their breeding behaviour and other aspects of their life history.

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