balancing
bal·ance
B0035600 (băl′əns)Bal·ance
B0035600 (băl′əns)balancing
(ˈbælənsɪŋ)| Noun | 1. |  balancing - getting two things to correspond; "the reconciliation of his checkbook and the bank statement" |
Balancing
balancing
[′bal·əns·iŋ]Balancing
Balancing
the balancing of rotating machine parts (the rotor of a turbine or electric motor, a crankshaft, pulleys, and so on). For most rotors in machinery, the axis of rotation is the axis passing through the centers of the bearing surfaces of the journals. Misalignment of that axis and the principal axis of inertia, which can result from errors in the fabrication technology of the part or from design features, gives rise to uncompensated centrifugal forces and moments, causing rapid wear on the bearings, increased vibration of the machine, bending oscillations of its components, and so on.
In the balancing operation, the axes are brought into alignment by placing balancing weights on the part tested, by removing unbalanced (excess) weights, or (in some special cases) by centering the article at the points where the principal central axis of inertia intersects the surface of the part; the axis of rotation passes through those points. Balancing is done on balancing machines. The choice of the required number of planes for corrections is determined by the type of balancing machine used. Depending on the mutual positions of the principal central axis of inertia, the axis of rotation, and the axis of the part, a distinction is made between static balancing, dynamic balancing, and balancing of flexible articles (dynamic straightening). Axes 2–2 and 3–3 (see Figure 1) coincide in static balancing and dynamic balancing.
Static balancing is used when the principal central axis of inertia becomes displaced parallel to the axis of rotation. In the case of a part with an unbalanced mass m and a balancing weight P (see Figure la), balancing involves compensating for the centrifugal force generated by the mass m as it rotates, and is brought about by positioning the weight P in one correcting plane. The relationship between the balancing weight P and the displacement e of the center of gravity (displacement of axes) is given by the formula P =∊ G/r, where G is the force of gravity and r is the radius at which the weight is mounted. The term “static balance” has its historical roots in the fact that mass imbalance can be detected statically by placing the part on straight horizontal guides on which a rotor will turn heavy side downward because of the gravitational force acting on the unbalanced mass. However, this is an imprecise method, and static balancing under dynamic conditions is preferred.
Dynamic balancing is used when there is an angular displacement of the principal central axis of inertia relative to the technological axis of rotation; the axes then intersect at the center of gravity of the part (see Figure lb). The relationship between the balancing weights P and the angular displacement φ of the principal central axis of inertia is expressed by the formula P =φI g/rl, where I is the moment of inertia of the part, g is gravitational acceleration, and l is the axial distance between the weights. In this case dynamic unbalance is a consequence of the centrifugal moment and can be offset by placing the weights in two correction planes generating a compensating couple of centrifugal forces of arm l.
Balancing of flexible parts (dynamic straightening) is used when the displacement of the principal central axis of inertia relative to the axis of rotation stems from bending of the axis of the article being balanced and when the purpose of balancing is to bring the axes into alignment. Figure lc shows a bent rotor near the first critical velocity. In this case balancing is brought about by positioning balancing weights in three or more correction planes. The equilibrant of the centrifugal forces and moments of a system with three weights must be zero. The relationship between the balancing weights is given by the formulas
P1 = (b 2 - b 3)P2/ (b3- b1)
P3 = (b1 - b 2)P2/ (b3 - b 1)
where b1, b2, and b3 are the axial coordinates of the correction planes. Four weights must be placed in four correction planes in order to achieve balancing near the second critical velocity, and so forth.
All of these aspects of imbalance are capable of acting on the article simultaneously, in which case the balancing problem will be complex. Only in some individual cases is it feasible to rely on only one mode of balancing—for example, static balancing is adequate in the case of flat articles. Quality balancing work requires that the balancing tolerances be set on the articles, and these tolerances are expressed by convention in the allowable displacement of the center of gravity ∊(in microns) or in the allowable imbalance u = rP (in g-cm).
REFERENCES
Artobolevskii, I. I, “Uravnoveshivanie sil inertsii ploskikh mekhanizmov.” Izv. nauchno-issledovatel’skogo in-ta mashinostroeniia,1935, no. 10.Krylov, A. N. “O dinamicheskom uravnoveshivanii rotorov i giro-skopov.”lzv. nauchno-issledovatel’skogo in-ta mashinostroeniia, 1935, no. 7.
Krylov, A. N. O nekotorykh differentsial’nykh uravneniiakh matematicheskoifiztki, imeiushchikh prilozhenie v tekhnicheskikh voprosakh,5th ed. Moscow-Leningrad, 1950.
Shitikov, B. V. Dinamicheskaia balansirovka rotorov. Moscow, 1951.
Den Hartog, J. P. Mekhanicheskie kolebaniia. Moscow, 1960. (Translated from English.)
Timoshenko, S. P. Kolebaniia v inzhenernom dele,2nd ed. Moscow, 1967. (Translated from English.)
V. N. BARKE
Balancing
a genre of circus art centered on the performer’s ability to maintain his equilibrium in any unstable position of the body while on a tightrope, large ball, or trapeze. It is often combined with acrobatics and juggling.
balancing
Balancing
Balancing
A process sometimes used by state and federal courts in deciding between the competing interests represented in a case.
Used frequently to decide constitutional cases, balancing is one of two main legal decision-making methods, the other being categorization or Strict Construction. Balancing involves weighing competing rights against each other and analyzing the relative strengths of many factors. A balancing decision is dependent upon the circumstances of each case. Therefore, the outcome is difficult to predict. By contrast, categorization is a classification and labeling process. It involves identifying a right and how it was infringed upon and analogizing these findings to a previously decided case or precedent. Hence, the outcome is more predictable.
Balancing of Competing Interests in the U.S. Supreme Court
Balancing may take one of two forms in cases before the U.S. Supreme Court. In the first, the Court may measure competing interests against each other and determine which carries the most weight. For example, in New York v. Ferber, 458 U.S. 747, 102 S. Ct. 3348, 73 L. Ed. 2d 1113 (1982), the Court upheld a statute criminalizing distribution of Child Pornography because the evil eliminated by the statute far outweighed any infringement on free speech interests. In the second form of balancing, the Court attempts to "strike a balance" between competing interests. Thus, in Tennessee v. Garner, 471 U.S. 1, 105 S. Ct. 1694, 85 L. Ed. 2d 1 (1985), the Court held that a police officer may use Deadly Force to stop a fleeing felon if the officer has Probable Cause to believe that the suspect poses a threat of serious physical harm to others. In Garner, the Court did not find that one interest clearly outweighed the other. Instead, both the state's interest in law enforcement and the individual's interest in being free from harm were weighed in the analysis and given due recognition.
Balancing was first used by the U.S. Supreme Court as one of its principal modes of judicial analysis in the late 1930s and early 1940s when the judiciary began to reject the rigid formalism and mechanical Jurisprudence characteristic of the nineteenth and early twentieth centuries. Before the balancing era began in earnest with lochner v. new york, 198 U.S. 45, 25 S. Ct. 539, 49 L. Ed. 937 (1905), the Court held that a New York statute setting maximum work hours was constitutional because such regulation was within the state's Police Power. In reaching this decision, the Court did not attempt to balance the rights of the individuals against the state's interests, but it took a straightforward look at the language of the statute and found it valid. This earlier Court stated: "The purpose of a statute must be determined from the natural and legal effect of the language employed… . It seems to us that the real object and purpose [of the statute] were simply to regulate the hours of labor between the master and his employees."
Early proponents of balancing included such prominent Supreme Court justices as oliver wendell holmes jr., louis d. brandeis, and harlan f. stone, all of whom sat on the Court in the early to middle 1900s. Holmes, sometimes called the patron saint of the anti-formalist movement, was one of the first to espouse the idea that the law is and should be an evolving product of social experience. He assailed the notion that rigid formulas could be applied to all situations before the Court. "[T]he law is a logical development, like everything else," he wrote. In a similar vein, Brandeis criticized the Court for ignoring contemporary social, political, and economic problems. He said, "[W]hether a measure relating to the public welfare is Arbitrary or unreasonable … should be based upon a consideration of relevant facts, actual or possible" (Adams v. Tanner, 244 U.S. 590, 37 S. Ct. 662, 61 L. Ed. 1336 [1917] [Brandeis, J., dissenting]). In another case, he wrote: "Whether a law enacted in the exercise of the police power is justly subject to the charge of being unreasonable or arbitrary can ordinarily be determined only by a consideration of the contemporary conditions, social, industrial, and political, of the community to be affected thereby. Resort to such facts is necessary, among other things, in order to appreciate the evils sought to be remedied and the possible effects of the remedy proposed" (Truax v. Corrigan, 257 U.S. 312, 42 S. Ct. 124, 66 L. Ed. 254 [1921] [Brandeis, J., dissenting]). Similarly, Stone forcefully advocated "consideration of all the facts and circumstances" in a case, including societal conditions that affected the parties, the controversy, and the outcome (DiSanto v. Pennsylvania, 273 U.S. 34, 47 S. Ct. 267, 71 L. Ed. 524 [1927] [Stone, J., dissenting]).
The Court uses a balancing approach most often to decide cases where constitutionally protected individual rights conflict with governmental interests. Many of the landmark constitutional cases of the 1960s, 1970s, and 1980s were decided in this manner, including roe v. wade, 410 U.S. 113, 93 S. Ct. 705, 35 L. Ed. 2d 47 (1973), which legalized Abortion. In reaching its decision in Roe, the Court found that in the first trimester of pregnancy, a woman's right to privacy outweighed the state's interest in protecting health, but in the later stages of pregnancy, the state's interest gradually outweighed the woman's.
Contrary to popular belief, however, the Court has not used balancing as its primary method of deciding constitutional cases. In fact, some of the most important constitutional cases of the twentieth century were decided without any balancing of competing interests. For example, balancing was not used to decide brown v. board of education, 347 U.S. 483, 74 S. Ct. 686, 98 L. Ed. 873 (1954) (outlawing segregated public schools); gideon v. wainwright, 372U.S. 335, 83 S. Ct. 792, 9 L. Ed. 2d 799 (1963) (guaranteeing indigent defendants appointed counsel in felony cases); and griswold v. connecticut, 381 U.S. 479, 85 S. Ct. 1678, 14 L. Ed. 2d 510 (1965) (outlawing state laws prohibiting contraceptives).
Balancing has always aroused controversy among legal scholars and judges. Critics contend that it gives too much discretion to judges and amounts to a usurpation of the legislative function. They maintain that it is a vague and arbitrary method of measuring unequal interests against each other and that it results in unpredictable decision making. One vocal critic of balancing is Justice Antonin Scalia. In his dissenting opinion in Bendix Autolite Corp. v. Midwesco Enterprises, 486 U.S. 888, 108 S. Ct. 2218, 100 L. Ed. 2d 896 (1988), he characterized the balancing of competing interests as an illusion. "[T]he scale analogy is not really appropriate," he wrote, "since the interests on both sides are incommensurate. It is more like judging whether a particular line is longer than a particular rock is heavy."
Scalia's frontal attack on balancing gained force in the 1990s when Scalia was joined on the Court by other justices who shared his philosophy that the Constitution should be construed strictly and literally. Evidence that Scalia's view was held by others on the Court can be found in the 1995 decision Vernonia School District 47J v. Acton, 515 U.S.646, 115 S. Ct. 2386, 132 L. Ed. 2d 564 (U.S. 1995), which held that schools could legally perform random drug tests on student athletes. The decision employed a straightforward analysis of the rationality of the school's policy to conduct random drug tests and dismissed concerns about infringement of the students' Fourth Amendment right to be free from unreasonable searches. Writing for the majority, Scalia stated: "The most significant element in this case is … that the policy was undertaken in furtherance of the government's responsibilities, under a public school system, as guardian and tutor of children entrusted to its care." The Court held that the testing was a type of search that "a reasonable guardian and tutor might undertake."
Three justices disagreed vehemently. Writing for the dissent, Justice Sandra Day O'Connor emphasized her belief that the decision did not give due recognition to the students' constitutional rights and went too far in its broad approval of "intrusive, blanket searches of school children, most of whom are innocent, for evidence of serious wrongdoing." Under the ruling, she said, students no longer enjoyed "the Fourth Amendment's … most basic … protection: its strong preference for an individualized suspicion requirement."
Justice O'Connor's dissent in Acton echoed her strong approval of balancing competing interests and assessing a statute's intrusion on individual rights. O'Connor expressed her belief that balancing is an essential step in the Court's decision-making process, in Employment Division, Department of Human Resources v. Smith, 494 U.S. 872, 110 S. Ct. 1595, 108 L. Ed. 2d 876 (1990). The respondents in Smith were Native Americans who were fired from their jobs because they ingested peyote as part of a religious ceremony. The Court held that the state could deny them unemployment benefits without violating the Free Exercise Clause of the First Amendment. O'Connor concurred with the result but took issue with the majority's failure to consider the effect the disputed statute had on the free exercise of religion. "To me," O'Connor wrote, "the sounder approach—the approach more consistent with our role as judges to decide each case on its individual merits—is to apply [a] test in each case to determine whether the burden on the specific plaintiffs before us is constitutionally significant and whether the particular … interest asserted by the State before us is compelling."
Balancing of Competing Interests in Other State and Federal Courts
Although the U.S. Supreme Court generates close scrutiny of its decisions when it applies a balancing test to resolve high-profile or controversial issues before it, it is not the only court that resolves issues by balancing competing interests at stake in a legal dispute. Indeed, every day across the country state and federal courts are asked to balance the competing interests of litigants in determining the admissibility of evidence, the appropriateness of a sentence, or the viability of an appeal.
For example, state and Federal Rules of Evidence call for the exclusion of relevant evidence when its Probative value is substantially outweighed by the danger of unfair prejudice or by considerations of undue delay, waste of time, or the needless presentation of cumulative or confusing evidence. Consequently, before one party may introduce relevant evidence over another party's objection, the judge must balance the competing interests that would be served by excluding or admitting the evidence in question.
State and federal sentencing guidelines also generally require judges to balance the aggravating and Mitigating Circumstances underlying a criminal offense before imposing a particular sentence on a defendant. Aggravating factors are those factors that justify a more severe punishment and are typically introduced by the prosecution, victim, or victim's family. Mitigating factors are those factors that justify a less severe sentence and are typically introduced by the defendant, the defendant's attorney, or witnesses speaking on behalf of the defendant.
Finally, appellate courts often engage in some form of balancing to review the lawfulness of a lower court decision. In addition, to the above examples from the U.S. Supreme Court, appellate courts employ a variety of standards of review by which they evaluate the record for error using some form of balancing analysis. For example, the substantial evidence standard of review requires appellate courts to determine if a lower court's decision was supported by sufficient evidence to avoid being overturned, meaning that the appellate court must weigh the evidence offered by the parties to some extent. Appellate courts applying the arbitrary and capricious standard of review must not only examine the gravity of the alleged arbitrary or capricious conduct in the lower court, but they must also take into consideration any evidence that makes the lower court's decision reasonable or justifiable.
Further readings
Alexy, Robert. 2003. "Constitutional rights, balancing, and rationality." Ratio Juris 16 (June): 131-140.
Columbia Law Review. 1978. 78:1022.
Friendly, Fred W. 1984. The Constitution: That Delicate Balance. New York: Random House.
Gottlieb, Stephen E., ed. 1993. Public Values in Constitutional Law. Ann Arbor, Mich.: Univ. of Michigan Press.
Hastings Law Journal. 1994. 45 (April): 711, 835, 969.
Yale Law Journal. 1987. 96 (April): 943.
Cross-references
Child Pornography; Deadly Force; Fourth Amendment; Judicial Review; Jurisprudence; Police Power; Precedent; Probable Cause; Strict Construction.
balancing
- noun
Synonyms for balancing
noun getting two things to correspond
Synonyms
- reconciliation
Related Words
- equalisation
- equalization
- leveling