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.

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

2000 ◽  
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

Abstract 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 increases 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.

Transmission Error in Helical Synchronous Belt Drives in Bidirectional Operation: Influence of Pulley Flange Under No Load

2003 ◽  
Author(s):  
Masanori Kagotani ◽  
Kenichi Makita ◽  
Hiroyuki Ueda ◽  
Tomio Koyama
Keyword(s):  
Theoretical Analysis ◽  
Helix Angle ◽  
Transmission Error ◽  
Belt Drive ◽  
Alignment Error ◽  
Belt Drives ◽  
The Difference ◽  
Case Transmission ◽  
Synchronous Belt Drive ◽  
Outside Diameter

Helical synchronous belt drives are more effective than conventional synchronous belt drives with respect to reducing noise and transmission error per single pitch of the pulley. However, the helix angle of the tooth trace causes axial belt movement. Therefore, a flanged pulley is used in a helical synchronous belt drive. In the present study, the transmission error in a helical synchronous belt drive using a flanged pulley under installation tension was investigated both theoretically and experimentally for the case where the pulley was rotated in bidirectional operation. The computed transmission error agrees well with the experimental results, thereby confirming the applicability of the proposed theoretical analysis for transmission error. In this case, transmission error is found to be generated by the difference in axial belt movement between the driving and driven sides, and by a change in the state of contact between the belt and pulley teeth flanks. The transmission error is reduced when the installation tension is set higher than the tension that causes a change in contact direction between the tooth flanks. In addition, transmission error does not occur when the driving and driven pulleys are of equal outside diameter and have no pulley alignment error.

Experimental/Numerical Analysis of the Timing Belt Drive Behavior of a V6 Engine

2003 ◽  
Author(s):  
Lionel Manin ◽  
Didier Remond ◽  
Jean-Philippe Gaborel
Keyword(s):  
Rotation Speed ◽  
Transmission Error ◽  
Strain Gauges ◽  
Belt Drive ◽  
Automotive Engine ◽  
Transmission Errors ◽  
Belt Drives ◽  
Harmonic Content ◽  
Timing Belt ◽  
The Time Domain

The timing belts used for automotive engine are asked to last more and more, and to be less noisy. In this way, it is necessary to simulate the behavior of the engine timing belt drives for optimization, but also to understand it from experimental analysis. The first objective of the work was to analyze experimentally the behavior of a V6 engine timing belt drive in terms of: pulley speeds, belt span tensions, transmission error. The second objective was to compare the measurements with simulations. The engine has four overhead camshafts and 4 valves per cylinder. The timing belt drive is composed of six pulleys, three idlers and an automatic tensioner. The crankshaft and the two first camshaft speeds are measured with optical encoders. Spans tensions are measured by means of strain gauges glued on the idler mounting axes. All the data are simultaneously recorded. Tests have been run from 800 rpm to 6000 rpm. Measured data are first analyzed in the time domain. Some phenomena like, nil span tensions, speeds acyclism and transmission error amplitude, are observed. Then, analyses of the harmonic content of the span tensions, pulley speeds and transmission errors between the crankshaft and the camshafts, are performed versus engine rotation speed. Finally, the tests have been simulated and comparisons are made between numerical and experimental results.

Factors Affecting Transmission Error in Helical Synchronous Belt With Error on Belt Side Face Under Bidirectional Operation

2009 ◽  
Author(s):  
Masanori Kagotani ◽  
Hiroyuki Ueda
Keyword(s):  
Static Condition ◽  
Axial Direction ◽  
Helix Angle ◽  
Transmission Error ◽  
Alignment Error ◽  
Factors Affecting ◽  
Belt Drives ◽  
Pitch Difference ◽  
Side Face

Helical synchronous belt drives are effective for reducing the noise and transmission error per single pitch of a pulley in comparison with conventional synchronous belt drives. However, the helix angle of the tooth trace causes axial belt movement. When the belt comes into contact with the pulley flange or the belt moves away from the pulley flange due to bidirectional operation, the accuracy of finishing on the belt side face affects the transmission error. In addition, it is considered that various factors such as transmitted torque, installation tension, pitch difference between the belt and the pulley, and alignment error between the driving and driven pulleys in the axial direction affect the behavior of the transmission error. In the present study, the influence of various factors on the transmission error in a helical synchronous belt with the error on the belt side face was investigated. Specifically, the case in which a flanged pulley is rotated in bidirectional operation under the quasi-static condition and transmitted torque was examined. The transmission error in bidirectional operation considering the error on the belt side face increased with the increase in transmitted torque, but was reduced when the installation tension was set to be high and when the pitch difference on the driving side was smaller than that on the driven side. In addition, the accuracy of rotation transmission improved when the alignment between the pulleys in the axial direction was set so that the belt on the driving side came into contact earlier with the pulley flange than did the belt on the driven side.

Noise and Life of Helical Timing Belt Drives

1999 ◽  
Vol 121 (2) ◽  
pp. 274-279 ◽  
Author(s):  
H. Ueda ◽  
M. Kagotani ◽  
T. Koyama ◽  
M. Nishioka
Keyword(s):  
Noise Level ◽  
Helix Angle ◽  
Tooth Profile ◽  
Belt Drives ◽  
Timing Belt

A new helical timing belt has been developed to reduce noise. In the present study, three belts, each having a curvilinear tooth profile and helix angles of 3 deg, 5 deg and 10 deg, respectively, were designed. The noise and life of the helical timing belt under a constant transmission force are compared with those of a conventional timing belt, in which the helix angle is zero. The noise level of the new helical belts having helix angles of 5 deg or 10 deg was found to be around 5 dB(A) lower than the conventional belt. The belt life was found to be almost identical for each type when the installation tension was set while the slack side tension for the transmission force was lowest. The results of the present study showed that helical belts should be selected for applications in which noise is a crucial factor.

Transmission Error in Helical Synchronous Belt Drives in Bidirectional Operation Under No Transmitted Load (Influence of Pulley Flanges)

2004 ◽  
Vol 126 (5) ◽  
pp. 881-888 ◽  
Author(s):  
Masanori Kagotani ◽  
Kenichi Makita ◽  
Hiroyuki Ueda ◽  
Tomio Koyama
Keyword(s):  
Axial Direction ◽  
Helix Angle ◽  
Transmission Error ◽  
Belt Drive ◽  
Alignment Error ◽  
Belt Drives ◽  
The Difference ◽  
Case Transmission ◽  
Synchronous Belt Drive ◽  
Outside Diameter

Helical synchronous belt drives are more effective than conventional synchronous belt drives with respect to reducing noise and transmission error per single pitch of the pulley. However, the helix angle of the tooth trace causes axial belt movement. Therefore, flanged pulleys are used in a helical synchronous belt drive, in order to prevent the belt from running off the pulley. In the present study, the transmission error in a helical synchronous belt drive using flanged pulleys under no transmitted load was investigated both theoretically and experimentally for the case where the pulley was rotated in bidirectional operation. The computed transmission error agrees well with the experimental results, thereby confirming the applicability of the proposed theoretical analysis for transmission error. In this case, transmission error is found to be generated by the difference in axial belt movement between the driving and driven sides, and by a change in the state of contact between the belt and pulley teeth flanks. The transmission error is reduced when the installation tension is set higher than the tension that causes a change in contact direction between the tooth flanks. In addition, transmission error does not occur when the driving and driven pulleys are of equal outside diameter and have no alignment error between the driving and driven pulleys in the axial direction.

Factors Affecting Transmission Error in Helical Synchronous Belt With Error on Belt Side Face Under Bidirectional Operation

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Masanori Kagotani ◽  
Hiroyuki Ueda
Keyword(s):  
Static Condition ◽  
Axial Direction ◽  
Helix Angle ◽  
Transmission Error ◽  
Alignment Error ◽  
Factors Affecting ◽  
Belt Drives ◽  
Pitch Difference ◽  
Side Face

Helical synchronous belt drives are effective for reducing the noise and transmission error per single pitch of a pulley, as compared with conventional synchronous belt drives. However, the helix angle of the tooth trace causes axial belt movement. When the belt comes into contact with the pulley flange or moves away from the pulley flange due to bidirectional operation, the accuracy of finishing on the belt side face affects the transmission error. In addition, various factors, such as the transmitted torque, installation tension, pitch difference between the belt and the pulley, and alignment error between the driving and driven pulleys in the axial direction, are considered to affect the behavior of the transmission error. In the present study, the influence of various factors on the transmission error in a helical synchronous belt with the error on the belt side face was investigated. Specifically, the case in which a flanged pulley is rotated in bidirectional operation under the quasi-static condition and transmitted torque was examined. The transmission error in bidirectional operation considering the error on the belt side face increased with an increase in the transmitted torque, but was reduced when the installation tension was set to be high and when the pitch difference on the driving side was smaller than that on the driven side. In addition, the accuracy of rotation transmission improved when the alignment between the pulleys in the axial direction was set so that the belt on the driving side came into contact with the pulley flange earlier than the belt on the driven side.

Influence of Idler on Transmission Error in Synchronous Belt Drives (Under Transmission Force)

2003 ◽  
Vol 125 (2) ◽  
pp. 404-410 ◽  
Author(s):  
Kenichi Makita ◽  
Masanori Kagotani ◽  
Hiroyuki Ueda ◽  
Tomio Koyama
Keyword(s):  
Helix Angle ◽  
Transmission Error ◽  
Experimental Results ◽  
Belt Drive ◽  
Belt Drives ◽  
Synchronous Belt Drive

Synchronous belt drives are widely used in various machines in order to transmit rotation accurately and synchronously. In these machines, idlers are commonly used to increase the angle of contact on the pulley and to avoid obstacles. However, the generating source of the transmission error under a transmission force with an idler remains unclear. In the present study, transmission error over a period of one pitch of the pulley was investigated both theoretically and experimentally for a synchronous belt drive attached an idler when a transmission force acted on the belt span. The experimental results agree closely with the computed results. The transmission error is greatly affected by change in the meshing state in the incomplete meshing sections. The idler position at which the transmission error is reduced exists even if the transmission torque increases. In addition, transmission error is reduced when the helix angle is increased.

Theoretical Analysis of Transmission Error in Helical Synchronous Belt With Error on Belt Side Face Under Bidirectional Operation

2009 ◽  
Vol 131 (8) ◽  
Author(s):  
Masanori Kagotani ◽  
Hiroyuki Ueda
Keyword(s):  
Theoretical Analysis ◽  
Helix Angle ◽  
Transmission Error ◽  
Belt Drive ◽  
Belt Drives ◽  
Axial Movement ◽  
Side Face ◽  
The Difference ◽  
Synchronous Belt Drive

Synchronous belt drives are occasionally required to transmit rotation accurately and are often employed in bidirectional operation. For transmission error per single pitch of the pulley, a helical synchronous belt with a helix angle of the tooth trace is effective. However, this belt causes axial movement because of the axial belt tooth load. When the belt comes into contact with the pulley flange or the belt moves away from the pulley flange due to bidirectional operation, the accuracy of finishing on the belt side face affects the transmission error. In the present study, the transmission error considering the error on the belt side face in a helical synchronous belt drive that uses flanged pulleys under the quasistatic condition and transmitted torque was investigated theoretically and experimentally for the case in which the pulley was rotated in bidirectional operation. The calculated transmission error coincided well with the experimentally obtained transmission error. Under forward rotation, the transmission error having a period of one rotation of the belt is caused by the error on the belt side face when the belt comes into contact with the pulley flange. Under reverse rotation, the transmission error is generated by a change in the belt tension due to the application of a transmitted torque and by the difference in axial belt movements between the driving and driven sides when the belt moves away from the pulley flange.

Experimental and Theoretical Comparison of the Precision of Flame Atomic Absorption, Fluorescence, and Emission Measurements

1981 ◽  
Vol 35 (3) ◽  
pp. 317-324 ◽  
Author(s):  
N. W. Bower ◽  
J. D. Ingle
Keyword(s):  
Atomic Absorption ◽  
Flicker Noise ◽  
Power Spectra ◽  
Inner Filter Effect ◽  
Atomic Emission ◽  
Noise Power ◽  
Experimental Conditions ◽  
Noise Characteristics ◽  
Fluorescence Measurements ◽  
Flame Atomic Absorption

Theoretical equations and experimental evaluation procedures for the determination of the precision of flame atomic absorption, emission, and fluorescence measurements are presented. These procedures and noise power spectra are used to evaluate the precision and noise characteristics of atomic copper measurements with all three techniques under the same experimental conditions in an H2-air flame. At the detection limit, emission and fluorescence measurements are limited by background emission shot and flicker noise whereas absorption measurements are limited by flame transmission lamp flicker noise. Analyte flicker noise limits precision at higher analyte concentrations for all three techniques. Fluctutations in self-absorption and the inner filter effect are shown to contribute to the noise in atomic emission and fluorescence measurements.

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