Abstract: The 3-roll Planetary Cross Mill developed in the middle of 1970’s is a new type mill with huge reduction and high efficiency. It provides an economical method for rolling semifinished and finished rounds. For roughing process of wire, tube blank and light section, this mill can get through the same reduction in a single pass as would be done by 7-8 stands in a conventional roughing line. Consequently, it is found very advantageous to replace the conventional roughing train in an existing bar or light section plant with a planetary cross mill in consideration of higher productivity, less energy consumption, better product quality, and higher level of automatization. Relevant factors such as kinematics, construction, and determination of characteristic parameter and rolling force and so on have been calculated theoretically with a view to establishing a suitable design.
Abstract: The calculation for the caster angle of cardan shaft in the skew rolling mill is more complicated than that in general rolling mill. Furthermore the affected factors are comparatively greater for the angle of cardan shaft in the skew rolling mill. In order to prevent the slide block of cardan shaft from wearing seriously, the cardan shaft in the skew rolling mill must be rational designed. This article presents the calculating formula of the caster angle of cardan shaft and discusses principles for designing rational cardan shaft in the skew rolling mill.
Abstract: It is important to improve the quality of strip shape in present production. This paper offers some key factors which affect the strip shape, such as the original shape, patterns of work and back-up rolls, disposed of bending force and heat crown through the practical measurement and the theoratical calculation, in order to obtain an optimium strip shape.
Abstract: A Cam plastometer is adapted. The experimental study of the resistance to plastic deformation of four types of steel (200Cr 40Cr, T8A, Tl2A) has been made during the compression of the specimen under high temperature and high speed. The experimental range was as follows:temperature 850-1150℃;rate 5-80S-1; and extent of reduction emax=lnho/h=ln2. This paper mainly analyes the influence of the temperature, rate and the extant of the reduction on the resistance to deformation of these four type's of steel, and results of 20Cr and T8A are in compar-sion with 40Cr and Tl2A. In this paper, there are a formula for calculating resistance to deformation and some graphic charts which may be useful for engineers and technicians. The experimatal result of T8A is compared to the other study of some foreign scholars.
Abstract: In order to ensure that a certain degree of transmission accuracy, the remains deformation of gear teeth must be restricted within a certain range. In other words, the allowable remains deformation depends on the accuracy of the transmission and the conditions under which the gear is working. Based on a large number of test results, the relationship between remains deformation and static bending strength limit σFilms was obtained as follows: σFilms=σ1(δ/m)K. Where σ1-the gear bending stress at the moment when 1 um remains deformation is produced for unit module. K - a coefficient which is dependent on the material and its heat treatment method, σ1 and K for spheroidal cast iron gears are shoun in this paper.
This article sums up the testing results of bending fatigue strength of three kinds of Baintic ductile iron gears. The testing method is an accelerated test for determining the fatigue strength of gears. For calculating the bending fatigue stress 《ISO/TC60 424E Calculation of tooth strength of spur and helical gears》 is adopted. When the number of basic cycles is No = 3×106, the bending fatigue limit stresses σFlim（R = 0. 99） are shown as follows:
The measurements and surfaces where failure occurred are analyzed.
Abstract: This paper is through the investegation of the result of life test over one hundred and thirty pairs of Bainitic Ductile Iron gears, perfectly prored that the tooth strength of gears made from this material is the highest of all sort ductile iron gears. Thereby it possesses a broad developing prospect. Authors have Conducted the pitting and bending durability test of gear tooth with tow sort materials of possessing ourselves, features ducctile iron -Copper-Malybdenum and Vanadium-Tiandium Bainitic and abtained the respective functions of S-N curve with reliability R = 0.99 and the relevant value of fatigue limit stress σFlim. Therefore it would supply the system datum to the design and manufacture of this sort gears and also would offer a referance for the "principle for the calculation of tooth strength of spur and helical gears" of " ISO" When it augment the inadequate datum of fatigue limit stress of ductile iron gears. Authors arc applying this datum abtaining from above test to tackle the practical are problem of gears in the industry also abtaining a good effects
Abstract: Hobbing the middle hardness surface gears with Hss tools is one of the important machining methods. This paper introduces the experimental results of cutting forces in the gears bobbing and discusses the effect of cutting conditions on the cutting forces of bobbing process. In spite of the faet that cutting forces for bobbing the middle hardness surfuce gears （HRc36-46） are weaker than those of soft surface gears of the same material, the cutting force gradient for bobbing the middle hardness surfuee gears is much higher than that of the soft surface gears. It is suggtsted that the attention be paid to dynamic characteristics of bobbing process. Besides, the experimental result shows that it is possible to machine the middle hardness surface gears on an ordinary bobbing machine under the rational cutting conditions.
Abstract: This paper analyzed the fundamental parameters of gear reducer series type ZQ they are in wide use for cranes, some problems have been dissected in the parameters, Meanwhile some new parameters have been studied for 5-50 tf overhead travelling cranes. The new parameters will be of benefit to rational arrangement of transmitting power, raise of load-carrying capacity of reducer, decrease of the size and weight of reducer, and also improvement of lubrication condition of gear,etc.
Abstract: In this paper we derive the formula for computing the envelope of a bi-parametric family of surfaces, when they are expressed in parameters. We also develop a graph-analytic method for cacula ting cross roller shapes with revolving surfaces, when they are considered as envelopes of a bi-parametric family of spheres.
Abstract: At present there are still few programs for calculating either discrete quantities or discrete quantities and continuous quantities optimal design. However, if there are discrete quantities in the design variables, such as the numbers of gear teeth, gear modulus and the thichness of the steel plate, one needs a program for integer variables. This article describes a method based on the grid method which calculates iterative-ly according to the variations of design variables using continuous quantities or discrete quantities respectively to find the ideal optimal solution. Based on this method, a program has been developed for integer variables in optimal design using ALGOL, and some examples are also attached. This program is easy to understand and quite flexible. It could be helpful in calculating the solutions to small scale questions with discrete and continuous variables.
Abstract: Recently, in order to improve the loadcell performance, the loadcell is always designed in this form: the stress resulting from the measured load is forced to well-distribute and concentrate in one or several force paths of the elastic element of the loadcell. This concentrated stress is detected by the strarn gages, and the output will accurately correspond to the load. In this paper, the technique of the concentrated stress is summarized in a principle. The concentrated stress principle. It is explained in detail and the application of this technique for the loadcell design is also introduced by examples.
Abstract: Jor the production of narrow strip of less than 600 mm in width, a hot strip mill with a planetary mill as roughing mill and three to four 4-high mills as finishing mill was suggested. The features of the said mill are less in number of mill stands, lower in investment and easily operate. Hot strip mills of 750 and 450mm has been designed which can be used to produce strips of 1.25mm minimum thickness, up to 620 and 320mm in width and up to 6.5 and 3 tons in coil weight respectively. The planetary mill used is of the clam type which we have developed and used successfully twice in a pilot plant. The important features of clam type planetary mill are: higher in mill rigidity, lower in weight simpler in synchronous mechanism of upper and lower planetary rolls. The feasibility of using this hind of hot strip mill to roll narraw strip has been discussed.
Abstract: This paper is briefly analysed the problems of travelling mechanism redactor on 5-50tf trolley overhead travelling Crane. The principle of plane quadratic enveloping worm transmission and its characteristic. It is suggestion that by means of the plane quadratic enveloping worm instead of of vertical type spur gear reductor in order to improving its transmission performance.
Monthly, started in 1955 Supervising institution：Ministry of Education Sponsoring Institution：University of Science and Technology Beijing Editorial office：Editorial Department of Chinese Journal of Engineering Publisher：Science Press Chairperson：Ren-shu Yang Editor-in-Chief：Ai-xiang Wu ISSN 2095-9389CN 2095-9389
