Universal joint

The lip seal, or oil. seal, used on modern centrifugal pumps is borrowed from the automotive industry. The lip seal was born with the invention of the automobile transmission and the universal joint in the early days of the family ear. It would effectively retain the transmission fluid and U-joint grea.se on jalopies with rumble seats. It really hasn t changed much in design since the 1920s. 

Kardangelenk, n. Cardan joint, universal joint, kardieren, v.t. card (wool, etc.), kardinalrot, a. cardinal (-red). 

Kreuzgelenk, n. universal joint, kreuzgeschichtet, a. cross-bedded. 

Uniton, m. plain shade, solid shade. Universal-arznei, /. universal remedy, cure all. -gelenk, n. universal joint, -mittel, n. = Universalarznei. 

Using a rear-wheel-drive vehicle as an example, a prop shaft delivers power from the transmission output, near the middle of the vehicle, to the differential that drives the wheels at the rear. If this prop shaft is designed to be stiff, which is normally the case, it could not be rigidly attached to the transmission output at one end and the differential at the other because of the differences in vertical movement between the drive wheels and the chassis. Typically, two universal joints are inserted into the drivetrain to accommodate this situation. 

Following the operating principle of the most commonly used universal joint, the input shaft and the output shaft both terminate in yokes that are oriented in mutually perpendicular planes. The branches of each yoke are pinned to a cross connector so that each yoke can pivot about its beam of the cross. This mechanism was employed in the sixteenth century by Italian mathematician Geronimo Cardano, who used it to maintain a shipboard compass in a horizontal plane, regardless of the movement of the ship. Consequently it is often called a Cardan joint. 

In a front-wheel-drive car, the drive wheels experience not only the road-induced vertical motion of the rear wheels hut also must rotate about a vertical axis to accommodate steering. Several different configurations of constant-velocity universal joints have been developed to manage such motion. These constant-velocity joints are larger and more expensive than the joint described above. 

Society of Automotive Engineers. (1979). Universal Joint and Driveshaft Design Manual. Warrendale, PA Society of Automotive Engineers. 

Jackshafts Some machine-trains use an extended or spacer shaft, called a jackshaft, to connect the driver and a driven unit. This type of shaft may use any combination of flexible coupling, universal joint, or splined coupling to provide the flexibility required making the connection. Typically, this type of intermediate drive is used either to absorb torsional variations during speed changes or to accommodate misalignment between the two machine-train components. 

Universal joints There are a variety of universal joints used to transmit torsional power. In most cases, this type of intermediate drive is used where some misalignment between the drive and driven unit is necessary. Because of the misalignment, the universal s pivot points generate a unique forcing function that influences both the dynamics and vibration profile generated by a machine-train. 

Figure 44.3 illustrates a typical double-pivot universal joint. This type of joint, which is similar to those used in automobiles, generates a unique frequency at four times (4x) the rotational speed of the shaft. Each of the pivot-point bearings generates a passing frequency each time the shaft completes a revolution. 

Figure 44.3 Typical double-pivot universal joint...

In universal-type jackshafts like the one illustrated in Figure 44.57, improper lubrication results in non-uniform power transmission. The absence of a uniform grease film causes the pivot points within the universal joints to bind and restrict smooth power transmission. 

The spherical pendulum, which consists of a mass attached by a massless rigid rod to a frictionless universal joint, exhibits complicated motion combining vertical oscillations similar to those of the simple pendulum, whose motion is constrained to a vertical plane, with rotation in a horizontal plane. Chaos in this system was first observed over 100 years ago by Webster [2] and the details of the motion discussed at length by Whittaker [3] and Pars [4]. All aspects of its possible motion are covered by the case, when the mass is projected with a horizontal speed V in a horizontal direction perpendicular to the vertical plane containing the initial position of the pendulum when it makes some acute angle with the downward vertical direction. In many respects, the motion is similar to that of the symmetric top with one point fixed, which has been studied ad nauseum by many of the early heroes of quantum mechanics [5]. 

Figure 6. Diagram of our 1-atm ion mobility spectrometer (IMS) apparatus (a) stainless steel source gas dilution volume, (b) septum inlet, (c) needle valve, (d) Nj source gas supply, (e) source and drift gas exhaust, (f) flow meter, (g) pressure transducer, (h) insulated box, (i) drift tube, (j) ion source, (k) Bradbury-Nielson gate, (I) Faraday plate/MS aperture, (m) drift gas inlet, (n) universal joint, (o) electrostatic lens element, (p) quadrupole mass filter, (q) 6"-diffusion pump, (r) first vacuum envelope, (s) channeltron electron multiplier, (t) second vacuum envelope, (u) 3"-dif-fusion pump, (v) Nj drift gas, (w) leak valve, (x) on/off valves, (y) fused silica capillary, (z) 4-liter stainless steel dilution volume, (aa) Nj gas supply.

Combustion control is currently a hot area of research in the U.S. and abroad. In addition to basic research at a number of universities, joint industry-university S T efforts are also underway to implement the control strategies developed by researchers in industry applications. Though some of the demonstrations have been made using gaseous fuels, the techniques can be extended to liquid fuels as well, and efforts are underway to accomplish this. It is hoped that future engines will perform equally well in off-design conditions, with improved reliability and easier maintenance, and reduced operational costs. 

Some items not usually described in elementary glass blowing texts, but frequently useful in vacuum apparatus, are magnetic seal-breakers, universal joints, and metal wire seals. Therefore their construction is described here. 

It is often necessary to make hardness measurements on curved surfaces, e.g. rollers or O rings. In the first example the product may be large enough for the hardness instrument to rest upon it, whilst in the second it would usually be possible to rest the product on the specimen table. In either case, some form of jig is required to locate the test piece and suitable examples and precautions to be taken are described in ISO 48. Any of the standard methods could be used for curved surfaces except that it is not possible to use a foot on concave surfaces. For large cylindrical surfaces, the hardness tester is either fitted with feet movable in universal joints which rest on the curved surface or the base of the instrument is fitted with two cylindrical rods which rest on the curved surface. The latter method can be used for surfaces with radius of curvature down to 50 mm. For surfaces having double curvature, only the method using movable feet is suitable. For small products and where the radius of curvature is too small to rest the instrument on the surface, the test piece is placed on the base of the instrument as with... 

Geer, R.D. 1978. Predicting the anaerobic degradation of organic chemical pollutants in waste water treatment plants from their electrochemical reduction behavior. In Montana University Joint Water Resources Research Center, Bozeman, MT, Completion Report No. 96... 

TS has been supported in parts by the Grants-in-Aid for Scientific Research (No. 20750018) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Nihon University Joint Research Grant for 2008, and by Nihon University Strategic Projects for Academic Research. JP thanks the Alexander von Humboldt Foundation for the renewal of his Humboldt Research Award. 

Fig. 3 I nterlocking rings and threaded systems can be considered as elemental working components of future molecular machines, (a) A prototype molecular ball and socket" joint, (b) A crude universal joint" the action...

Freely jointed chains are another form of flexible chains because of the free rotation of the universal joint between monomers however, monomers are... 

Fig. 18 Mechanical movements of one ring relative to the other in a catenane, which from a macroscopic viewpoint are reminiscent of movements of a ball and socket joint (top) and of a universal joint (bottom)...

A catenane is a molecule composed of two or more interlocked macrocyclic components. From a macroscopic mechanical viewpoint the movement of one ring relative to the other in a catenane is reminiscent of a ball and socket joint (Fig. 18, top) [81]. Similarly, twisting of one ring around the main axis of the catenane forces the other ring to rotate in the same direction in a manner reminiscent of an universal joint (Fig. 18, bottom) [81]. 

Bailey, A. K., andWeisel, G. R, 1976, Completion report Concentration of heavy metals in sediments of a hydroelectric impoundment Montana State University Joint Water Resources Research Center, 75 p. 

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