Load Distribution in Timing Belts

1978 ◽  
Vol 100 (2) ◽  
pp. 208-215 ◽  
Author(s):  
G. Gerbert ◽  
H. Jo¨nsson ◽  
U. Persson ◽  
G. Stensson
Keyword(s):  
Load Distribution ◽  
Test Procedure ◽  
Spring Constant ◽  
The Finite Element Method ◽  
Belt Drives ◽  
Exponential Character ◽  
Timing Belt ◽  
Steel Cord ◽  
The Subject ◽  
Theory And Experiment

A theory is presented for determining the distribution of the belt tension and the tooth load in timing belts. It appears that the distribution of both loads is of exponential character and one important parameter is the ratio between the spring constant of the tooth and the spring constant of the cord (a nondimensional number). Friction between the belt and the top of the pulley is also considered. This mostly influences the tooth load distribution. A criterion is presented for maximum tension ratio with respect to correct tooth action. Two belts are examined experimentally (steel cord-urethane and glass fiber cord-neoprene rubber). The spring constant of the tooth is determined both experimentally (a test procedure is presented) and theoretically (using the finite element method) and the agreement is good. The distribution of the belt tension in timing belt drives has been measured. The agreement between theory and experiment for the belts examined is satisfactory. Some discrepancies were observed. These will be the subject for further research.

Load distribution of timing belt drives transmitting variable torques

1995 ◽  
Vol 30 (4) ◽  
pp. 553-567 ◽  
Author(s):  
Nestor A. Karolev ◽  
Peter W. Gold
Keyword(s):  
Load Distribution ◽  
Belt Drives ◽  
Timing Belt

Influence of Planet Pin Stiffness on Load Sharing in Planetary Gear Drives

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Alfred N. Montestruc
Keyword(s):  
Planetary Gear ◽  
Load Sharing ◽  
Spring Constant ◽  
Spur Gears ◽  
The Finite Element Method ◽  
Specific Design ◽  
The Subject ◽  
Gear Drives ◽  
Gear Meshes ◽  
Spring Constants

Others have done significant work on the subject of load sharing among the planets of planetary gear drives; a brief review of that work is presented. Little work has been done, however, to evaluate the utility of the Hicks type flexible planet pins in improvement of load sharing in a planetary gear stage. This work shows the potential value of the three variations of the Hicks type flexible planet pin used on cantilever carriers, and a new design of a low spring constant planet pin that can be used on straddle type carriers. This is done by the calculation of the spring constants of gear meshes, bearings, and various designs of planet pins using the finite element method for a specific design of a planetary gear stage with spur gears and eight planets. The result showed significant differences. Low spring constant flexible pins are shown to have significantly superior load sharing characteristics.

Transmission Error in Helical Timing Belt Drives (Case of a Period of Pulley Pitch)

2000 ◽  
Vol 123 (1) ◽  
pp. 104-110 ◽  
Author(s):  
Masanori Kagotani ◽  
Hiroyuki Ueda ◽  
Tomio Koyama
Keyword(s):  
Helix Angle ◽  
Transmission Error ◽  
Face Advance ◽  
Experimental Conditions ◽  
Belt Drives ◽  
Noise Characteristics ◽  
Synchronous Rotation ◽  
Timing Belt ◽  
Belt Width ◽  
Static Conditions

Helical timing belts have been developed in order to reduce the noise that occurs when conventional timing belts are driven. Helical timing belts are characterized by synchronous rotation. Although several studies have been performed to clarify the noise characteristics and belt life of helical timing belts, the transmission error of these belts remains unclear. In the present study, the transmission error having a period of one pitch of the pulley was investigated both theoretically and experimentally for helical timing belt drives. Experimental conditions were such that the transmission force acts on the helical timing belts under quasi-static conditions and the belt incurs belt climbing at the beginning of meshing and at the end of meshing. Experimental results obtained for the transmission error agreed closely with the computed results. The computed results revealed that helical timing belts can be analyzed as a set of very narrow belts for which the helix angle is zero. The transmission error was found to decrease when the helix angle or the belt width increase within a range defined such that the face advance is less than one belt pitch. In addition, there exists an appropriate installation tension that reduces the transmission error.

Primary Hyperparathyroidism

1964 ◽  
Vol 10 (3) ◽  
pp. 228-234 ◽  
Author(s):  
H O Nicholas ◽  
James Allen Chamberlin
Keyword(s):  
Primary Hyperparathyroidism ◽  
Serum Calcium ◽  
Test Procedure ◽  
Total Serum ◽  
Renal Lithiasis ◽  
Routine Test ◽  
Total Serum Calcium ◽  
Reliable Diagnosis ◽  
The Subject

Abstract This paper presents the final results obtained by this laboratory during a 3½-year investigation of primary hyperparathyroidism. The project involved establishment of a routine test procedure for more reliable diagnosis of this condition; a study of the incidence of renal lithiasis in hyperparathyroidism, and, finally, the subject of the present paper-the obtaining of data to construct a nomogram for estimation of diffusible serum calcium from the total serum calcium and the albumin and globulin levels.

scholarly journals Double-arm steel connector of glass façades

2019 ◽  
Vol 97 ◽  
pp. 06012
Author(s):  
Izabela Major ◽  
Maciej Major ◽  
Zbigniew Respondek
Keyword(s):  
Load Distribution ◽  
Dynamic Effect ◽  
Wind Pressure ◽  
The Finite Element Method ◽  
Additional Element ◽  
Wind Gusts ◽  
Rectangular Element ◽  
Glass Facade ◽  
Maximum Stresses ◽  
Glass Façade

This paper presents a numerical analysis of a steel double-arm connector, according to the authors’ solution, designed for fixation of glass façades. The analysis was carried out in order to obtain a distribution of stresses and displacements, on the basis of which global displacements and maximum stresses were determined. An additional element of the solution was the use of the M8 bolt, as a linking element of the steel walls of both arms. The numerical simulation was performed using the ADINA program, which is based on the finite element method (FEM). The dynamic effect of wind gusts on the glass façade was assumed, taking into account both wind pressure and suction. The adoption of a rectangular element of the glass façade causes an unfavorable load distribution at the connection point. The conducted research allowed to determine displacements and stresses in a steel connector made of S355JR steel. The applicability of the proposed solution for glass façades with a height of up to 100 m has been demonstrated.

Poincare's Silence and Einstein's Relativity: The Role of Theory and Experiment in Poincaré's Physics

1970 ◽  
Vol 5 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Stanley Goldberg
Keyword(s):  
Special Theory ◽  
Theoretical Physics ◽  
Theory Of Relativity ◽  
Special Theory Of Relativity ◽  
Henri Poincaré ◽  
Home Town ◽  
Académie Des Sciences ◽  
The Subject ◽  
Theory And Experiment

It is a matter of record that Henri Poincaré never responded publicly to Einstein's Special Theory of Relativity (RT). Since almost no private papers of Poincaré are available, his attitude toward Einstein's work and his silence on that score become somewhat of a mystery. It is almost certain that Poincaré knew of Einstein's work in RT. First, he was fluent in German, having learned it as a young man when the Germans occupied his home town of Nancy in 1870. Second, he often reported to the members of the Académie des Sciences on current work in electrodynamics in Germany. It is highly improbable that he would have missed the abstract of Einstein's first paper on RT or the subsequent articles by Einstein on the subject, especially those which were translated into French, since they were in areas directly related to his own interests in theoretical physics.

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